0001363829-20-000116 | 10-Q | XBRL Viewer

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Cover Page - shares	3 Months Ended
Cover Page - shares	Mar. 31, 2020	May 05, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Entity File Number	001-33289
Entity Registrant Name	Enstar Group LTD
Entity Incorporation, State or Country Code	D0
Entity Address, Address Line One	Windsor Place
Entity Address, Address Line Two	3rd Floor
Entity Address, Address Line Three	22 Queen Street
Entity Address, City or Town	Hamilton
Entity Address, Postal Zip Code	HM JX
Entity Address, Country	BM
City Area Code	441
Local Phone Number	292-3645
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity Central Index Key	0001363829
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false
Ordinary Shares
Document Information [Line Items]
Title of 12(b) Security	Ordinary shares, par value $1.00 per share
Trading Symbol	ESGR
Security Exchange Name	NASDAQ
Series D Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/1,000th Interest in a 7.00%
Trading Symbol	ESGRP
Security Exchange Name	NASDAQ
Series E Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/1,000th Interest in a 7.00%
Trading Symbol	ESGRO
Security Exchange Name	NASDAQ
Voting Ordinary Shares
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		18,624,473
Nonvoting Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,509,682

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
ASSETS
Available-for-sale, at fair value	$ 2,279,073	$ 2,041,724
Funds held - directly managed	1,134,921	1,187,552
Equities, at fair value	641,850	729,721
Other investments, at fair value	2,326,984	2,524,420
Equity method investments	337,474	326,277
Total investments (Note 4 and Note 10)	12,383,370	13,207,513
Cash and cash equivalents	815,878	703,085
Restricted cash and cash equivalents	345,097	352,692
Premiums receivable	631,447	576,980
Deferred tax assets (Note 18)	171,729	170,984
Reinsurance balances recoverable on paid and unpaid losses (net of allowance: 2020 — $143,327) (Note 6)	1,666,381	1,684,372
Reinsurance balances recoverable on paid and unpaid losses, at fair value (Note 6 and Note 10)	653,396	695,518
Insurance balances recoverable (net of allowance: 2020 — $6,985) (Note 9)	435,613	448,855
Funds held by reinsured companies	827,382	408,735
Deferred acquisition costs	162,135	153,505
Goodwill and intangible assets	215,960	216,468
Other assets	823,121	744,608
TOTAL ASSETS	19,131,509	19,363,315
LIABILITIES
Losses and loss adjustment expenses (Note 8)	8,084,444	7,808,116
Losses and loss adjustment expenses, at fair value (Note 8 and Note 10)	2,345,543	2,621,122
Defendant asbestos and environmental liabilities (Note 9)	822,716	847,685
Unearned premiums	760,307	746,775
Insurance and reinsurance balances payable	451,530	373,180
Deferred tax liabilities (Note 18)	11,434	16,074
Debt obligations (Note 13)	1,541,554	1,191,207
Other liabilities	431,204	464,014
TOTAL LIABILITIES	14,448,732	14,068,173
COMMITMENTS AND CONTINGENCIES (Note 20)
REDEEMABLE NONCONTROLLING INTEREST (Note 14)	392,773	438,791
SHAREHOLDERS’ EQUITY (Note 15)
Treasury shares, at cost (Series C Preferred shares 2020 and 2019: 388,571)	(421,559)	(421,559)
Joint Share Ownership Plan (voting ordinary shares, held in trust 2020: 565,630)	(566)	0
Additional paid-in capital	1,825,798	1,836,778
Accumulated other comprehensive income (loss)	(34,656)	7,171
Retained earnings	2,375,073	2,887,892
Total Enstar Shareholders’ Equity	4,276,599	4,842,183
Noncontrolling interest (Note 14)	13,405	14,168
TOTAL SHAREHOLDERS’ EQUITY	4,290,004	4,856,351
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTEREST AND SHAREHOLDERS’ EQUITY	19,131,509	19,363,315
Voting Ordinary shares (issued and outstanding 2020: 18,610,068; 2019: 18,001,823)
SHAREHOLDERS’ EQUITY (Note 15)
Ordinary shares	18,610	18,002
Non-voting convertible ordinary Series C Shares (issued and outstanding 2020 and 2019: 2,599,672)
SHAREHOLDERS’ EQUITY (Note 15)
Ordinary shares	2,600	2,600
Non-voting convertible ordinary Series E Shares (issued and outstanding 2020 and 2019: 910,010)
SHAREHOLDERS’ EQUITY (Note 15)
Ordinary shares	910	910
Series C Preferred Shares (issued and held in treasury 2020 and 2019: 388,571)
SHAREHOLDERS’ EQUITY (Note 15)
Preferred Shares	389	389
Series D Preferred Shares (issued and outstanding 2020 and 2019: 16,000)
SHAREHOLDERS’ EQUITY (Note 15)
Preferred Shares	400,000	400,000
Series E Preferred Shares (issued and outstanding 2020 and 2019: 4,400)
SHAREHOLDERS’ EQUITY (Note 15)
Preferred Shares	110,000	110,000
Short-term Investments
ASSETS
Trading, at fair value	18,249	51,490
Available-for-sale, at fair value	138,900	128,335
Fixed maturity investments
ASSETS
Trading, at fair value	5,644,819	6,346,329
Available-for-sale, at fair value	$ 2,140,173	$ 1,913,389

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
ASSETS
Investments, available-for-sale, at fair value, amortized cost	$ 2,342,582	$ 2,042,454
Investments, allowance for credit losses	16,271	0
Reinsurance recoverable, allowance for credit loss	143,327
Insurance balance recoverable, allowance for credit loss	$ 6,985	$ 3,818
SHAREHOLDERS’ EQUITY
Ordinary shares, par value (in dollars per share)	$ 1	$ 1
Ordinary shares issued (in shares)	22,119,750	21,511,505
Ordinary shares outstanding (in shares)	22,119,750	21,511,505
Treasury shares, preferred at cost (in shares)	388,571	388,571
Treasury shares, voting ordinary shares, held in trust (in shares)	565,630
Voting Ordinary Shares
SHAREHOLDERS’ EQUITY
Ordinary shares issued (in shares)	18,610,068	18,001,823
Ordinary shares outstanding (in shares)	18,610,068	18,001,823
Series C Non-Voting Convertible Ordinary Shares
SHAREHOLDERS’ EQUITY
Ordinary shares issued (in shares)	2,599,672	2,599,672
Ordinary shares outstanding (in shares)	2,599,672	2,599,672
Series E Non-Voting Convertible Ordinary Shares
SHAREHOLDERS’ EQUITY
Ordinary shares issued (in shares)	910,010	910,010
Ordinary shares outstanding (in shares)	910,010	910,010
Series C Preferred Shares
SHAREHOLDERS’ EQUITY
Preferred shares issued (in shares)	388,571	388,571
Series D Preferred Stock
SHAREHOLDERS’ EQUITY
Preferred shares issued (in shares)	16,000	16,000
Preferred shares outstanding (in shares)	16,000	16,000
Series E Preferred Stock
SHAREHOLDERS’ EQUITY
Preferred shares issued (in shares)	4,400	4,400
Preferred shares outstanding (in shares)	4,400	4,400
Short-term Investments
ASSETS
Investments, available-for-sale, at fair value, amortized cost	$ 138,596	$ 128,311
Investments, allowance for credit losses	0
Fixed maturity investments
ASSETS
Investments, available-for-sale, at fair value, amortized cost	2,203,986	$ 1,914,143
Investments, allowance for credit losses	$ 16,271

CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
INCOME
Net premiums earned	$ 259,897	$ 335,287
Fees and commission income	7,528	6,681
Net investment income	77,840	78,696
Net realized and unrealized gains (losses)	(634,476)	460,791
Other income	20,444	5,812
Total income	(268,767)	887,267
EXPENSES
Net incurred losses and loss adjustment expenses	107,894	312,404
Life and annuity policy benefits	0	96
Acquisition costs	66,586	93,788
General and administrative expenses	113,511	112,074
Interest expense	13,415	11,036
Net foreign exchange gains	(11,930)	(3,850)
Total expenses	289,476	525,548
EARNINGS (LOSS) BEFORE INCOME TAXES	(558,243)	361,719
Income tax benefit (expense)	5,175	(4,749)
Earnings from equity method investments	12,450	8,772
NET EARNINGS (LOSS)	(540,618)	365,742
Net loss attributable to noncontrolling interest	32,722	2,148
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR	(507,896)	367,890
Dividends on preferred shares	(8,925)	(9,139)
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$ (516,821)	$ 358,751
Earnings (Loss) per ordinary share attributable to Enstar:
Basic (in dollars per share)	$ (23.98)	$ 16.71
Diluted (in dollars per share)	$ (23.98)	$ 16.57
Weighted average ordinary shares outstanding:
Basic (in shares)	21,549,844	21,463,499
Diluted (in shares)	21,779,906	21,645,862

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
NET EARNINGS (LOSS)	$ (540,618)	$ 365,742
Other comprehensive income (loss), net of income taxes:
Unrealized holding gains (losses) on fixed income available-for-sale investments arising during the period	(58,735)	3,663
Reclassification adjustment for change in allowance for credit losses recognized in net earnings	13,212	0
Reclassification adjustment for net realized gains included in net earnings	212	61
Unrealized gains (losses) arising during the period, net of reclassification adjustments	(45,311)	3,724
Total cumulative currency translation adjustment	(686)	(801)
Total other comprehensive income (loss)	(45,997)	2,923
Comprehensive income (loss)	(586,615)	368,665
Comprehensive loss attributable to noncontrolling interest	36,892	2,064
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO ENSTAR	$ (549,723)	$ 370,729

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($)	Total	Ordinary Shares Voting Ordinary Shares	Ordinary Shares Series C Non-Voting Convertible Ordinary Shares	Ordinary Shares Series E Non-Voting Convertible Ordinary Shares	Preferred Stock Series C Preferred Shares	Preferred Stock Series D Preferred Stock	Preferred Stock Series E Preferred Stock	Treasury Shares (Series C Preferred Shares)	Joint Share Ownership Plan — Voting Ordinary Shares, Held in Trust	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Currency translation adjustment	Defined benefit pension liability	Unrealized gains (losses) on available-for-sale investments	Retained Earnings	Noncontrolling Interest (excludes Redeemable Noncontrolling Interest)
Balance, beginning of period at Dec. 31, 2018		$ 17,950,000	$ 2,600,000	$ 910,000	$ 389,000	$ 400,000,000	$ 110,000,000	$ (421,559,000)	$ 0	$ 1,804,664,000	$ 10,440,000	$ 10,986,000		$ 441,000	$ 1,976,539,000	$ 12,056,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares		8,000							0	466,000
Shares repurchased		0								0
Amortization of share-based compensation										3,977,000
Change in other comprehensive income (loss)	$ 2,923,000											(803,000)		3,642,000
Net earnings (loss)	358,751,000														365,742,000
Net loss attributable to noncontrolling interest	2,148,000														2,148,000	396,000
Dividend on preferred shares															(9,139,000)
Change in redemption value of redeemable noncontrolling interests															(262,000)
Balance, end of period at Mar. 31, 2019	4,280,164,000	17,958,000	2,600,000	910,000	389,000	400,000,000	110,000,000	(421,559,000)	0	1,809,107,000	13,279,000	10,183,000	$ (987,000)	4,083,000	2,335,028,000	12,452,000
Balance, beginning of period at Dec. 31, 2019	4,856,351,000	18,002,000	2,600,000	910,000	389,000	400,000,000	110,000,000	(421,559,000)	0	1,836,778,000	7,171,000	8,548,000		(432,000)	2,887,892,000	14,168,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares		701,000							(566,000)	(1,251,000)
Shares repurchased		(93,000)								(12,433,000)
Amortization of share-based compensation										2,704,000
Change in other comprehensive income (loss)	(45,997,000)											(686,000)		(41,141,000)
Net earnings (loss)	(516,821,000)														(540,618,000)
Net loss attributable to noncontrolling interest	32,722,000														32,722,000	(763,000)
Dividend on preferred shares															(8,925,000)
Change in redemption value of redeemable noncontrolling interests															10,150,000
Balance, end of period at Mar. 31, 2020	$ 4,290,004,000	$ 18,610,000	$ 2,600,000	$ 910,000	$ 389,000	$ 400,000,000	$ 110,000,000	$ (421,559,000)	$ (566,000)	$ 1,825,798,000	$ (34,656,000)	$ 7,862,000	$ (945,000)	$ (41,573,000)	$ 2,375,073,000	$ 13,405,000

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
OPERATING ACTIVITIES:
Net earnings (loss)	$ (540,618)	$ 365,742	$ (540,618)
Adjustments to reconcile net earnings (loss) to cash flows provided by operating activities:
Realized gains on sale of investments	(1,918)	(270)
Unrealized losses (gains) on investments	636,394	(460,521)
Depreciation and other amortization	11,393	7,900
Earnings from equity method investments	(12,450)	(8,772)
Sales and maturities of trading securities	800,631	1,486,423
Purchases of trading securities	(284,860)	(1,379,411)
Other non-cash items	2,760	4,687
Changes in:
Reinsurance balances recoverable on paid and unpaid losses	57,860	(256,706)
Funds held by reinsured companies	(418,647)	(598,471)
Losses and loss adjustment expenses	16,817	685,834
Defendant asbestos and environmental liabilities	(24,969)	(5,807)
Insurance and reinsurance balances payable	78,693	67,653
Unearned premiums	13,532	108,424
Premiums receivable	(54,467)	67,489
Other operating assets and liabilities	(122,039)	22,944
Net cash flows provided by operating activities	158,112	107,138
INVESTING ACTIVITIES:
Sales and maturities of available-for-sale securities	465,065	5,839
Purchase of available-for-sale securities	(778,151)	(147)
Purchase of other investments	(160,814)	(225,961)
Proceeds from other investments	85,720	58,980
Purchase of equity method investments	0	(9,762)
Other investing activities	0	(1,956)
Net cash flows used in investing activities	(388,180)	(173,007)
FINANCING ACTIVITIES:
Dividends on preferred shares	(8,925)	(9,139)
Repurchase of shares	(12,526)	0
Receipt of loans	364,000	344,000
Repayment of loans	(14,000)	(102,000)
Net cash flows provided by financing activities	328,549	232,861
EFFECT OF EXCHANGE RATE CHANGES ON FOREIGN CURRENCY CASH AND CASH EQUIVALENTS	6,717	(3,925)
NET INCREASE IN CASH AND CASH EQUIVALENTS	105,198	163,067
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	1,055,777	982,584	982,584
CASH AND CASH EQUIVALENTS, END OF PERIOD	1,160,975	1,145,651	1,055,777
Supplemental Cash Flow Information:
Income taxes paid, net of refunds	6,596	9
Interest paid	9,747	14,215
Reconciliation to Consolidated Balance Sheets:
Cash and cash equivalents				$ 815,878	$ 703,085	$ 718,050
Restricted cash and cash equivalents				345,097	352,692	427,601
Cash, cash equivalents and restricted cash	$ 1,160,975	$ 1,145,651	$ 982,584	$ 1,160,975	$ 1,055,777	$ 1,145,651

Significant Accounting Policies

3 Months Ended

Mar. 31, 2020

Accounting Policies [Abstract]

SIGNIFICANT ACCOUNTING POLICIES

1. SIGNIFICANT ACCOUNTING POLICIES

Basis of Preparation

These unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, these financial statements reflect all adjustments consisting of normal recurring items considered necessary for a fair presentation under U.S. GAAP. The results of operations for any interim period are not necessarily indicative of results for the full year. These financial statements should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2019. All significant inter-company transactions and balances have been eliminated. In these notes, the terms "we," "us," "our," "Enstar," or "the Company" refer to Enstar Group Limited and its consolidated subsidiaries. Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications had no impact on net earnings.

Use of Estimates

The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Our actual results may differ materially from these estimates. Results of changes in estimates are reflected in earnings in the period in which the change is made. Accounting policies that we believe are most dependent on assumptions and estimates are considered to be our critical accounting policies and are related to the determination of:


•	liability for losses and loss adjustment expenses ("LAE");


•	reinsurance balances recoverable on paid and unpaid losses;


•	defendant asbestos and environmental liabilities and related insurance balances recoverable;


•	valuation allowances on reinsurance balances recoverable and deferred tax assets;


•	impairment charges, including credit allowances on investment securities classified as available-for-sale ("AFS"), and impairments on goodwill, intangible assets and deferred charge assets;


•	gross and net premiums written and net premiums earned;


•	fair value measurements of investments;


•	fair value estimates associated with accounting for acquisitions;


•	fair value estimates associated with loss portfolio transfer reinsurance agreements for which we have elected the fair value option; and

•

redeemable noncontrolling interests.

Updated Accounting Policies

The following accounting policies have been updated to reflect our adoption of Accounting Standards Update ("ASU") 2016-13 - Financial Instruments - Credit losses - Measurement of Credit Losses on Financial Instruments, effective January 1, 2020 as described in detail below under "New Accounting Standards Adopted in 2020."

Short-term investments and fixed maturity investments

We perform a detailed analysis every reporting period to identify any credit losses on our investment portfolios not measured at fair value through net earnings.

Some of the factors that we consider when assessing whether an allowance for credit losses is required on our debt securities include: (1) the extent to which the fair value has been less than the amortized cost; (2) the financial condition, near-term and long-term prospects of the issuer, including the relevant industry conditions and trends, and implications of rating agency actions and offering prices; (3) the likelihood of the recoverability of principal and interest;

and (4) whether it is more likely than not that we will be required to sell the security prior to an anticipated recovery in value.

With effect from January 1, 2020, credit losses on our AFS debt securities are recognized through an allowance account which is deducted from the amortized cost basis of the security, with the net carrying value of the security presented on the consolidated balance sheet at the amount expected to be collected. To calculate the amount of the credit loss, we compare the present value of the expected future cash flows with the amortized cost basis of the AFS debt security, with the amount of the credit loss recognized being limited to the excess of the amortized cost basis over the fair value of the AFS debt security, effectively creating a “fair value floor”. See "New Accounting Standards Adopted in 2020" below for the discussion on our adoption of the credit losses standard.

For our AFS debt securities that we do not intend to sell or for which it is more likely than not that we will not be required to sell before an anticipated recovery in value, we separate the credit loss component of any unrealized losses from the amount related to all other factors and report the credit loss component in net realized investment gains (losses) in our consolidated statements of earnings. The unrealized losses related to non-credit factors is reported in other comprehensive income. The allowance for credit losses account is adjusted for any additional credit losses, write-offs and subsequent recoveries.

For our AFS debt securities where we record a credit loss, a determination is made as to the cause of the credit loss and whether we expect a recovery in the fair value of the security. For our AFS debt securities where we expect a recovery in fair value, the constant effective yield method is utilized, and the investment is amortized to par.

For our AFS debt securities that we intend to sell or for which it is more likely than not that we will be required to sell before an anticipated recovery in fair value, the full amount of the unrealized loss is included in net realized investment gains (losses). The new cost basis of the investment is the previous amortized cost basis less the credit loss recognized in net realized investment gains (losses). The new cost basis is not adjusted for any subsequent recoveries in fair value.

We report the investment income accrued on our AFS debt securities within other assets and therefore separately from the underlying AFS debt securities. In addition, due to the short-term period during which accrued investment income remains unpaid, which is typically six months, since the coupon on our AFS debt securities is paid semi-annually, we have elected not to establish an allowance for credit losses on our accrued investment income balances. Accrued investment income is written off through net realized investment gains (losses) at the time the issuer of the debt security defaults or is expected to default on payments.

Uncollectible debt securities are written off when we determine that no additional payments of principal or interest will be received.

Reinsurance Balances Recoverable on Paid and Unpaid Losses

Amounts recoverable from reinsurers are estimated in a manner consistent with the underlying liability for losses and loss adjustment expenses. We report our reinsurance balances recoverable on paid and unpaid losses net of an allowance for estimated uncollectible amounts. The allowance is based upon our ongoing review of the outstanding balances and reflects factors such as the duration of the collection period, credit quality, changes in reinsurer credit standing, default rates specific to the individual reinsurer, the geographical location of the reinsurer, contractual disputes with reinsurers over individual contentious claims, contract language or coverage issues, industry analyst reports and consensus economic forecasts.

A probability-of-default methodology that reflects current and forecasted economic conditions is used to estimate the allowance for uncollectible reinsurance due to credit-related factors. See "New Accounting Standards Adopted in 2020" below for the discussion on our adoption of the credit losses standard.

The allowance also includes estimated uncollectible amounts related to dispute risk with reinsurers. Amounts deemed to be uncollectible, including amounts due from known insolvent reinsurers, are written off against the allowance.

Changes in the allowance, as well as any subsequent collections of amounts previously written off, are reported as part of the net incurred losses and loss adjustment expenses in our consolidated statements of earnings.

On an ongoing basis, we also evaluate and monitor the financial condition of our reinsurers under voluntary schemes of arrangement to minimize our exposure to significant losses from potential insolvencies.

Premiums Receivable and Unearned Premium Reserves

Premiums are recognized as revenues on a pro-rata basis over the coverage period. Unearned premium reserves represent the unexpired portion of policy premiums. For retrospectively rated contracts as well as those whose written premium amounts are recorded based on premium estimates at inception, accrued premiums arising from changes to these estimates are included in premium balances receivable where appropriate. Premium balances receivable are reported net of an allowance for expected credit losses as appropriate. The allowance is based upon our ongoing review of amounts outstanding, historical loss data, including delinquencies and write-offs, current and forecasted economic conditions and other relevant factors. However, the credit risk on our premiums receivable balances is substantially reduced where we have the ability to cancel the underlying policy if the policyholder does not pay the related premium.

New Accounting Standards Adopted in 2020

ASU 2020-03 – Codification Improvements to Financial Instruments

In March 2020, the Financial Accounting Standards Board ("FASB") issued ASU 2020-03, which makes narrow-scope improvements to various topics within the codification relating to financial instruments, including the new credit losses standard. The amendments related to certain specific issues covered by the ASU were effective immediately upon the issuance of the ASU, while certain specific issues covered by the ASU and affecting the credit losses standard in ASU 2016-13 are effective in 2020 for those entities that have already adopted ASU 2016-13. We adopted the amendments in this ASU upon its issuance and that adoption did not have a material impact on our consolidated financial statements and the related disclosures.

ASUs 2016-13, 2018-19, 2019-04, 2019-05, 2019-10 and 2019-11, Financial Instruments – Credit Losses – Measurement of Credit Losses on Financial Instruments

In June 2016, the FASB issued ASU 2016-13, which is codified in Accounting Standards Codification ("ASC") 326 - Financial Instruments - Credit Losses, amending the guidance on the impairment of financial instruments and significantly changing how entities measure credit losses for most financial assets and certain other financial instruments, including reinsurance balances recoverable on paid and unpaid losses that are not measured at fair value through net earnings. The ASU replaced the “incurred loss” approach that was previously applied to determine credit losses with an “expected loss” model for financial instruments measured at amortized cost. Under the "expected loss" model, the estimate of expected credit losses should consider historical information, current information, as well as reasonable and supportable forecasts, including estimates of prepayments. The expected credit losses and subsequent adjustments to such losses are recorded through an allowance account that is deducted from the amortized cost basis of the financial asset, with the net carrying value of the financial asset presented on the consolidated balance sheet at the amount expected to be collected.

ASU 2016-13 also amends the other-than-temporary impairment ("OTTI") model that was previously applicable to AFS debt securities, with the new approach now requiring the recognition of impairments relating to credit losses through an allowance account and limiting the amount of credit loss to the difference between a security’s amortized cost basis and its fair value. This revised approach records the full effect of reversals of any credit losses in current period earnings, compared to previous guidance where this reversal was amortized over the lifetime of the security. Under this revised approach, the length of time a security has been in an unrealized loss position will no longer be considered in determining whether to record a credit loss. In addition, the historical and implied volatility of the fair value of a security and recoveries or declines in fair value after the balance sheet date will no longer be considered when making a determination of whether a credit loss exists.

We adopted ASU 2016-13 and all the related amendments on January 1, 2020 using the modified retrospective approach for our financial instruments carried at amortized cost, and prospectively for our AFS debt securities as required by the standard, resulting in an overall reduction in retained earnings of $6.1 million as summarized below:

•

A cumulative effect adjustment of $3.0 million relating to our financial instruments carried at amortized cost, which primarily relates to our insurance balances recoverable on paid and unpaid losses. We already carried significant specific allowances for credit losses of $147.6 million on our reinsurance balances recoverable on paid and unpaid losses, relating primarily to our Non-life Run-off segment and therefore the adoption of this standard did not have a material impact on our balance sheet; and

•

$3.1 million related to our AFS debt securities whose fair values were less than their amortized cost basis.

Recently Issued Accounting Pronouncements Not Yet Adopted

Note 2 - "Significant Accounting Policies" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019 describes accounting pronouncements that were not adopted as of December 31, 2019. Those pronouncements have not yet been adopted unless discussed above in "New Accounting Standards Adopted in 2020." In addition, the following accounting pronouncement was issued by the FASB during the three months ended March 31, 2020 and is yet to be adopted.

ASU 2020-04 – Reference Rate Reform (ASC 848)

In March 2020, the FASB issued ASU 2020-04 – Reference Rate Reform – Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which is codified in ASC 848 and which provides entities with temporary optional expedients and exceptions to the existing US GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition from the London Inter-bank Offered Rate ("LIBOR") and other inter-bank offered rates to alternative reference rates, such as the Secured Overnight Financing Rate ("SOFR").

Under the provisions of this ASU, entities can elect not to apply certain modification accounting requirements to contracts affected by reference rate reform, if certain criteria are met. An entity that makes this election would not have to remeasure the contracts at the modification date or reassess a previous accounting determination. Entities can also elect various optional expedients for hedging relationships affected by reference rate reform, if certain criteria are met. In addition, entities can make a one-time election to sell, transfer or both sell and transfer debt securities classified as held-to-maturity (“HTM”) that refer to a rate affected by reference rate reform, to AFS or to trading. However, such debt securities must have been classified as HTM before January 1, 2020. Once elected the amendments in the ASU must be applied prospectively for all eligible contract modifications.

The ASU was effective upon issuance and can be applied through to December 31, 2022. As we transition from LIBOR to alternative reference rates, we may elect the temporary optional expedients and exceptions to the existing US GAAP guidance on contract modifications and hedge accounting permitted by the ASU, as appropriate, in order to ease the potential financial reporting burdens we may to encounter during the transition period. We do not expect the adoption of this standard to have a material impact on our consolidated financial statements and disclosures.

Acquisitions	3 Months Ended
Acquisitions	Mar. 31, 2020
Business Combinations [Abstract]
Acquisitions	2. ACQUISITIONS On October 30, 2019, we completed the acquisition of Morse TEC LLC ("Morse TEC"). For further details, refer to Note 3 - "Acquisitions" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019.

Significant New Business	3 Months Ended
Significant New Business	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
SIGNIFICANT NEW BUSINESS	3. SIGNIFICANT NEW BUSINESS Lyft On March 31, 2020, we entered into a novation agreement with affiliates of Lyft, Inc. (“Lyft”) and certain underwriting companies of Zurich North America (“Zurich”). Enstar will reinsure legacy automobile business underwritten by Zurich between October 1, 2015 and September 30, 2018 and reinsured by Lyft’s wholly owned subsidiary, Pacific Valley Insurance Company ("PVIC") for consideration of $465.0 million. Under a separate agreement, PVIC will provide retrocession coverage to Enstar in excess of an $816.0 million limit. The transaction was effective on March 31, 2020. The consideration was recorded as funds held on March 31, 2020 and was received in April 2020. Aspen On March 2, 2020, we entered into an adverse development cover reinsurance agreement with Aspen Insurance Holdings Limited. In the transaction, we will reinsure losses incurred on or prior to December 31, 2019 on a diversified mix of property, liability and specialty lines across the U.S., U.K. and Europe for a premium of $770.0 million. We will provide $770.0 million of cover in excess of a $3.8 billion retention, and an additional $250.0 million of cover in excess of a $4.8 billion retention. Completion of the transaction is subject to regulatory approvals and satisfaction of various other closing conditions. The transaction is expected to close in the second quarter of 2020. AXA Group On February 24, 2020, we entered into a loss portfolio transfer reinsurance agreement with AXA XL, a division of AXA, to reinsure specified legacy construction general liability multi-year policies. We will assume reinsurance reserves of approximately $225.0 million in the transaction. Completion of the transaction is subject to, among other things, regulatory approvals and satisfaction of various closing conditions. The transaction is expected to close in the second quarter of 2020. Munich Re On September 10, 2019, we signed an agreement with Great Lakes Insurance SE and HSB Engineering Insurance Limited, both subsidiaries of Munich Reinsurance Company ("Munich Re"), pursuant to which we will acquire certain portfolios from their Australian branches. In the transaction, which is subject to regulatory and Federal Court of Australia approval, we will receive total assets of approximately AUD$228.2 million (approximately $139.3 million) for assuming the associated net insurance reserves, which primarily relate to long tail insurance business. We are pursuing a portfolio transfer of the insurance business under Division 3A of Part III of Australia’s Insurance Act 1973 (Cth), which would provide legal finality for Munich Re and its subsidiaries. This transaction is expected to close in the third quarter of 2020.

Investments

3 Months Ended

Mar. 31, 2020

Investments, Debt and Equity Securities [Abstract]

INVESTMENTS

4. INVESTMENTS

We hold: (i) trading portfolios of short-term and fixed maturity investments and equities, carried at fair value; (ii) AFS portfolios of short-term and fixed maturity investments, carried at fair value; (iii) other investments, carried at fair value; (iv) equity method investments; and (v) funds held - directly managed.

Short-Term and Fixed Maturity Investments

Asset Types

The fair values of the underlying asset categories comprising our short-term and fixed maturity investments classified as trading and AFS and the fixed maturity investments included within our funds held - directly managed balance were as follows:



	March 31, 2020
	Short-term investments, trading		Short-term investments, AFS		Fixed maturities, trading		Fixed maturities, AFS		Fixed maturities, funds held - directly managed		Total
U.S. government and agency	$	766	$	34,582	$	186,693	$	203,637	$	94,255	$	519,933
U.K. government	3,675		3,337		63,420		29,573		—		100,005
Other government	11,022		334		490,111		83,007		19,540		604,014
Corporate	2,368		99,277		3,649,143		1,233,289		554,614		5,538,691
Municipal	418		1,370		98,341		15,676		49,025		164,830
Residential mortgage-backed	—		—		229,723		155,027		83,168		467,918
Commercial mortgage-backed	—		—		523,207		130,878		219,419		873,504
Asset-backed	—		—		404,181		289,086		61,608		754,875
Total fixed maturity and short-term investments	$	18,249	$	138,900	$	5,644,819	$	2,140,173	$	1,081,629	$	9,023,770



	December 31, 2019
	Short-term investments, trading		Short-term investments, AFS		Fixed maturities, trading		Fixed maturities, AFS		Fixed maturities, funds held - directly managed		Total
U.S. government and agency	$	—	$	111,583	$	219,194	$	298,729	$	106,537	$	736,043
U.K. government	24,411		1,069		122,012		14,280		—		161,772
Other government	21,958		387		575,018		84,760		20,734		702,857
Corporate	5,121		13,915		4,007,386		1,067,256		603,389		5,697,067
Municipal	—		1,381		102,554		14,491		49,456		167,882
Residential mortgage-backed	—		—		258,412		127,219		86,205		471,836
Commercial mortgage-backed	—		—		571,129		98,557		230,343		900,029
Asset-backed	—		—		490,624		208,097		76,681		775,402
Total fixed maturity and short-term investments	$	51,490	$	128,335	$	6,346,329	$	1,913,389	$	1,173,345	$	9,612,888

Included within residential and commercial mortgage-backed securities as of March 31, 2020 were securities issued by U.S. governmental agencies with a fair value of $363.6 million (December 31, 2019: $356.9 million). Included within corporate securities as of March 31, 2020 were senior secured loans of $8.8 million (December 31, 2019: $31.4 million).

Contractual Maturities

The contractual maturities of our short-term and fixed maturity investments, classified as trading and AFS and the fixed maturity investments included within our funds held - directly managed balance are shown below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties.



As of March 31, 2020	Amortized Cost		Fair Value		% of Total Fair Value
One year or less	$	502,300	$	497,009	5.5	%
More than one year through two years	754,996		747,837		8.3	%
More than two years through five years	2,209,294		2,156,740		23.9	%
More than five years through ten years	2,080,140		2,049,319		22.7	%
More than ten years	1,439,507		1,476,568		16.3	%
Residential mortgage-backed	466,964		467,918		5.2	%
Commercial mortgage-backed	894,859		873,504		9.7	%
Asset-backed	829,598		754,875		8.4	%
	$	9,177,658	$	9,023,770	100.0	%

Credit Ratings

The following table sets forth the credit ratings of our short-term and fixed maturity investments classified as trading and AFS and the fixed maturity investments included within our funds held - directly managed balance as of March 31, 2020:



	Amortized Cost		Fair Value		% of Total		AAA Rated			AA Rated			A Rated			BBB Rated			Non- Investment Grade			Not Rated

U.S. government and agency	$	488,708	$	519,933	5.8	%	$	519,933		$	—		$	—		$	—		$	—		$	—
U.K. government	100,716		100,005		1.1	%	538			99,467			—			—			—			—
Other government	618,746		604,014		6.7	%	268,626			136,721			63,097			111,636			20,478			3,456
Corporate	5,622,480		5,538,691		61.3	%	140,194			602,836			2,908,118			1,594,296			277,738			15,509
Municipal	155,587		164,830		1.8	%	16,425			77,511			49,068			21,826			—			—
Residential mortgage-backed	466,964		467,918		5.2	%	395,148			26,892			3,085			1,602			35,489			5,702
Commercial mortgage-backed	894,859		873,504		9.7	%	621,883			93,167			78,379			57,187			5,867			17,021
Asset-backed	829,598		754,875		8.4	%	421,823			64,782			122,025			71,799			10,352			64,094
Total	$	9,177,658	$	9,023,770	100.0	%	$	2,384,570		$	1,101,376		$	3,223,772		$	1,858,346		$	349,924		$	105,782
% of total fair value							26.4		%	12.2		%	35.7		%	20.6		%	3.9		%	1.2		%

Unrealized Gains and Losses on AFS Short-term and Fixed Maturity Investments

The amortized cost, unrealized gains and losses, allowance for credit losses and fair values of our short-term and fixed maturity investments classified as AFS as of March 31, 2020 were as follows:



					Gross Unrealized Losses
As of March 31, 2020	Amortized Cost		Gross Unrealized Gains		Non-Credit Related Losses			Allowance for Credit Losses⁽¹⁾			Fair Value
U.S. government and agency	$	230,450	$	7,783	$	(14	)	$	—		$	238,219
U.K. government	33,953		—		(1,043		)	—			32,910
Other government	84,302		1,416		(2,377		)	—			83,341
Corporate	1,374,000		5,680		(30,844		)	(16,270		)	1,332,566
Municipal	16,799		250		(3		)	—			17,046
Residential mortgage-backed	153,268		2,943		(1,184		)	—			155,027
Commercial mortgage-backed	137,641		744		(7,506		)	(1		)	130,878
Asset-backed	312,169		195		(23,278		)	—			289,086
	$	2,342,582	$	19,011	$	(66,249	)	$	(16,271	)	$	2,279,073

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

The amortized cost, unrealized gains and losses and fair values of our short-term and fixed maturity investments classified as AFS as of December 31, 2019 were as follows:



As of December 31, 2019	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses (Non-OTTI)			Fair Value
U.S. government and agency	$	410,842	$	77	$	(607	)	$	410,312
U.K. government	15,067		282		—			15,349
Other government	84,116		1,119		(88		)	85,147
Corporate	1,081,713		4,026		(4,568		)	1,081,171
Municipal	15,963		20		(111		)	15,872
Residential mortgage-backed	127,704		240		(725		)	127,219
Commercial mortgage-backed	98,928		38		(409		)	98,557
Asset-backed	208,121		169		(193		)	208,097
	$	2,042,454	$	5,971	$	(6,701	)	$	2,041,724

Gross Unrealized Losses on AFS Short-term and Fixed Maturity Investments

The following table summarizes our short-term and fixed maturity investments classified as AFS that were in a gross unrealized loss position, for which an allowance for credit losses has not been recorded, as of March 31, 2020, aggregated by major security type and length of time in continuous unrealized loss position:



	12 Months or Greater					Less Than 12 Months					Total
As of March 31, 2020	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency	$	—	$	—		$	1,399	$	(14	)	$	1,399	$	(14	)
U.K. government	—		—			32,909		(1,043		)	32,909		(1,043		)
Other government	992		(110		)	40,315		(2,267		)	41,307		(2,377		)
Corporate	2,390		(432		)	532,456		(10,287		)	534,846		(10,719		)
Municipal	—		—			473		(3		)	473		(3		)
Residential mortgage-backed	—		—			33,738		(1,184		)	33,738		(1,184		)
Commercial mortgage-backed	—		—			93,706		(7,460		)	93,706		(7,460		)
Asset-backed	—		—			264,205		(23,278		)	264,205		(23,278		)
Total fixed maturity and short-term investments	$	3,382	$	(542	)	$	999,201	$	(45,536	)	$	1,002,583	$	(46,078	)

The following table summarizes our short-term and fixed maturity investments classified as AFS that are in a gross unrealized loss position as of December 31, 2019, aggregated by major security type and length of time in continuous unrealized loss position:



	12 Months or Greater					Less Than 12 Months					Total
As of December 31, 2019	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency	$	—	$	—		$	222,643	$	(607	)	$	222,643	$	(607	)
Other government	1,080		(23		)	37,796		(65		)	38,876		(88		)
Corporate	2,754		(306		)	461,772		(4,262		)	464,526		(4,568		)
Municipal	128		—			12,046		(111		)	12,174		(111		)
Residential mortgage-backed	—		—			65,992		(725		)	65,992		(725		)
Commercial mortgage-backed	—		—			79,606		(409		)	79,606		(409		)
Asset-backed	—		—			129,014		(193		)	129,014		(193		)
Total fixed maturity and short-term investments	$	3,962	$	(329	)	$	1,008,869	$	(6,372	)	$	1,012,831	$	(6,701	)

As of March 31, 2020 and December 31, 2019, the number of securities classified as AFS in an unrealized loss position for which an allowance for credit loss is not recorded was 896 and 563, respectively. Of these securities, the number of securities that had been in an unrealized loss position for twelve months or longer was 9 and 12, respectively.

The increase in the unrealized losses on our short-term and fixed maturity investments was attributable to widening credit spreads due to the recent disruption in global financial markets associated with the COVID-19 pandemic. The contractual terms of a majority of these investments do not permit the issuers to settle the securities at a price less than the amortized cost basis of the security. While credit spreads have increased, and in certain cases credit ratings were downgraded, we currently do not expect the issuers of these fixed income securities to settle them at a price less than their amortized cost basis and therefore it is expected that we will recover the entire amortized cost basis of each security. Furthermore, we do not intend to sell the securities that are currently in an unrealized loss position, and it is also not more likely than not that we will be required to sell the securities before the recovery of their amortized cost bases.

Allowance for Credit Losses

We adopted ASU 2016-13 and the related amendments on January 1, 2020 prospectively, and recognized an allowance for credit losses of $3.1 million on initial adoption of the guidance. Our allowance for credit losses is derived based on various data sources, multiple key inputs and forecast scenarios. These include default rates specific to the individual security, vintage of the security, geography of the issuer of the security, industry analyst reports, credit ratings and consensus economic forecasts.

To determine the credit losses on our AFS securities, we use the probability of default ("PD") and loss given default ("LGD") methodology through a third-party proprietary tool which calculates the expected credit losses based on a discounted cash flow method. The tool uses effective interest rates to discount the expected cash flows associated with each AFS security to determine its fair value, which is then compared with its amortized cost basis to derive the credit loss on the security.

The methodology and inputs used to determine the credit loss by security type are as follows:

•

Corporate and Government: Expected cashflows are derived that are specific to each security. The PD is based on a quantitative model that converts agency ratings to term structures that vary by country, industry and the state of the credit cycle. This is used along with macroeconomic forecasts to produce scenario conditioned PDs. The LGD is based on default studies provided by a third party which we use along with macroeconomic forecasts to produce scenario conditioned LGDs.


•	Municipals: Expected cash flows are derived that are specific to each security. The PD model produces scenario conditioned PD output over the lifetime of the municipal security. These PDs are based on key macroeconomic and instrument specific risk factors. The LGD is derived based on a model which uses assumptions specific to the municipal securities.

For corporates, government and municipal securities, we use an explicit reversion and a three year forecast period, which we consider to be a reasonable duration during which an economic forecast could continue to be reliable.

•

Asset backed, Commercial and Residential mortgaged-backed: Expected cash flows are derived that are specific to each security. The PD and LGD for each security is based on a quantitative model that generates scenario conditioned PD and LGD term structures based on the underlying collateral type, waterfall and other trustee information. This model also considers prepayments. For these security types, there is no explicit reversion and the forecasts are deemed reasonable and supportable over the life of the portfolio.

Due to the short-term period during which accrued investment income remains unpaid, which is typically six months since the coupon on our debt securities is paid semi-annually, we elected not to establish an allowance for credit losses on our accrued investment income balances. Accrued investment income is written off through net realized investment gains (losses) at the time the issuer of the debt security defaults or is expected to default on payments.

The table below provides a reconciliation of the beginning and ending allowance for credit losses on our AFS debt securities for the three months ended March 31, 2020:



	Other government			Corporate			Commercial mortgage backed			Total
Allowance for credit losses, beginning of period	$	—		$	—		$	—		$	—
Cumulative effect of change in accounting principle	(22		)	(2,987		)	(50		)	(3,059		)
Allowances for credit losses on securities for which credit losses were not previously recorded	—			(13,681		)	—			(13,681		)
Reductions for securities sold during the period	—			369			—			369
Reductions in the allowance for credit losses on securities we either intend to sell or more likely than not, we will be required to sell before the recovery of their amortized cost basis	22			29			49			100
Allowance for credit loss, end of period	$	—		$	(16,270	)	$	(1	)	$	(16,271	)

During the three months ended March 31, 2020 we did not have any write-offs charged against the allowance for credit losses or any recoveries of amounts previously written-off.

Our allowance for credit losses increased during the three months ended March 31, 2020 primarily due to widening credit spreads arising from the recent disruption in global financial markets associated with the COVID-19 pandemic, which resulted in a larger number of securities being in an unrealized loss position. In addition, our modeling process for determining credit losses was adjusted to take into account the adverse impact that the COVID-19 pandemic had on capital markets, and the global economy in general, which resulted in an increase in our allowance for credit losses as at March 31, 2020.

Other-Than-Temporary Impairment on AFS Fixed Maturity Investments

For the three months ended March 31, 2019, we did not recognize any other-than-temporary impairment losses on our AFS securities. We determined that no other-than-temporary credit losses existed as of December 31, 2019. A description of our other-than-temporary impairment process is included in Note 2 - "Significant Accounting Policies" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019.

As discussed in detail in Note 1 - "Significant Accounting Policies" above, we adopted ASU 2016-13 and the related amendments on January 1, 2020 with this new guidance replacing the OTTI model that was previously applicable to our AFS debt securities. The new approach now requires the recognition of impairments relating to credit losses through an allowance account and limits the amount of credit loss to the difference between a security’s amortized cost basis and its fair value.

Equity Investments

The following table summarizes our equity investments classified as trading:



	March 31, 2020		December 31, 2019
Publicly traded equity investments in common and preferred stocks	$	240,932	$	327,875
Exchange-traded funds	130,906		133,047
Privately held equity investments in common and preferred stocks	270,012		268,799
	$	641,850	$	729,721

Equity investments include publicly traded common and preferred stocks, exchange-traded funds and privately held common and preferred stocks. Our publicly traded equity investments in common and preferred stocks predominantly trade on major exchanges and are managed by our external advisors. Our investments in exchange-traded funds also trade on major exchanges.

Our privately held equity investments in common and preferred stocks are direct investments in companies that we believe offer attractive risk adjusted returns and/or offer other strategic advantages. Each investment may have its own unique terms and conditions and there may be restrictions on disposals. The market for these investments is illiquid and there is no active market. Included within the above balance as of March 31, 2020 and December 31, 2019 is an investment in the parent company of AmTrust Financial Services, Inc. ("AmTrust"), with a fair value of $241.3 million and $240.1 million, respectively. Refer to Note 19 - "Related Party Transactions" for further information.

Other Investments, at fair value

The following table summarizes our other investments carried at fair value:



	March 31, 2020		December 31, 2019
Hedge funds	$	1,055,448	$	1,121,904
Fixed income funds	463,717		481,039
Equity funds	320,046		410,149
Private equity funds	309,219		329,885
CLO equities	83,740		87,555
CLO equity funds	66,938		87,509
Private credit funds	20,473		—
Other	7,403		6,379
	$	2,326,984	$	2,524,420

The valuation of our other investments is described in Note 10 - "Fair Value Measurements." Due to a lag in the valuations of certain funds reported by the managers, we may record changes in valuation with up to a three-month lag. We regularly review and discuss fund performance with the fund managers to corroborate the reasonableness of the reported net asset values and to assess whether any events have occurred within the lag period that would affect the valuation of the investments. Due to the adverse impact that the COVID-19 pandemic has had on capital markets, and the global economy in general, we recorded an estimate for unrealized losses for certain other investments that are typically reported on a lag basis. The following is a description of the nature of each of these investment categories:


•	Hedge funds may invest in a wide range of instruments, including debt and equity securities, and utilize various sophisticated strategies to achieve their objectives. We invest in a mixture of fixed income, equity and multi-strategy hedge funds.


•	Fixed income funds comprise a number of positions in diversified fixed income funds that are managed by third-party managers. Underlying investments vary from high-grade corporate bonds to non-investment grade senior secured loans and bonds, but are generally invested in liquid fixed income markets. These funds have regularly published prices.


•	Equity funds invest in a diversified portfolio of U.S. and international publicly-traded equity securities.


•	Private equity funds invest primarily in the financial services industry.


•	CLO equities comprise investments in the equity tranches of term-financed securitizations of diversified pools of corporate bank loans.


•	CLO equity funds invest primarily in the equity tranches of term-financed securitizations of diversified pools of corporate bank loans.


•	Private credit funds invest in direct senior or collateralized loans.


•	Others comprise various investments including real estate debt funds that invest primarily in European commercial real estate equity, call options on equities and a fund that provides loans to educational institutions throughout the U.S. and its territories.

The decrease in our other investments carried at fair value between March 31, 2020 and December 31, 2019 was primarily attributable to unrealized losses of $258.1 million due to the recent disruption in global financial markets associated with the COVID-19 pandemic, partially offset by net additional subscriptions of $75.1 million to fixed income funds, private credit funds, CLO equities and CLO equity funds.

As of March 31, 2020, we had unfunded commitments of $773.6 million to private equity funds.

Certain of our other investments are subject to restrictions on redemptions and sales that are determined by the governing documents, which limits our ability to liquidate those investments. These restrictions may include lock-ups, redemption gates, restricted share classes or side pockets, restrictions on the frequency of redemption and notice

periods. A gate is the ability to deny or delay a redemption request, whereas a side-pocket is a designated account for which the investor loses its redemption rights. Certain other investments may not have any restrictions governing their sale, but there is no active market and no guarantee that we will be able to execute a sale in a timely manner. In addition, even if certain other investments are not eligible for redemption or sales are restricted, we may still receive income distributions from those other investments. The table below details the estimated date by which proceeds would be received if we had provided notice of our intent to redeem or initiated a sales process as of March 31, 2020:



	Less than 1 Year		1-2 years		2-3 years		More than 3 years		Not Eligible/ Restricted		Total		Redemption Frequency
Hedge funds	$	325,882	$	576,616	$	—	$	102,600	$	50,350	$	1,055,448	Monthly to Bi-annually
Fixed income funds	460,684		—		—		—		3,033		463,717		Daily to Quarterly
Equity funds	320,046		—		—		—		—		320,046		Daily to Quarterly
Private equity funds	—		—		—		—		309,219		309,219		N/A
CLO equities	83,740		—		—		—		—		83,740		N/A
CLO equity funds	47,938		—		19,000		—		—		66,938		Quarterly to Bi-annually
Private credit funds	—		—		—		—		20,473		20,473		N/A
Other	—		—		—		—		7,403		7,403		N/A
	$	1,238,290	$	576,616	$	19,000	$	102,600	$	390,478	$	2,326,984

Equity Method Investments

The following table summarizes our equity method investments:



	March 31, 2020						December 31, 2019
	Investment		Ownership %		Carrying Value		Investment		Ownership %		Carrying Value
Enhanzed Re	$	154,050	47.4	%	$	197,206	$	154,050	47.4	%	$	182,856
Citco	50,000		31.9	%	51,504		50,000		31.9	%	51,742
Monument	26,600		26.6	%	57,737		26,600		26.6	%	60,598
Clear Spring	11,210		20.0	%	10,952		11,210		20.0	%	10,645
Other	24,963		~30%		20,075		24,963		~30%		20,436
	$	266,823			$	337,474	$	266,823			$	326,277

Refer to Note 19 - "Related Party Transactions" for further information regarding our investments in Enhanzed Re, Citco, Monument and Clear Spring.

As of March 31, 2020, we had unfunded commitments of $110.5 million related to equity method investments.

Funds Held

Under funds held arrangements, the reinsured company has retained funds that would otherwise have been remitted to our reinsurance subsidiaries. We either have (i) funds held by reinsured companies, which are carried at amortized cost and on which we receive a fixed crediting rate, or (ii) funds held - directly managed, which are carried at fair value and on which we receive the underlying return on the portfolio. The investment returns on both categories of funds held are recognized in net investment income and net realized and unrealized gains (losses). The funds held balance is credited with investment income and losses payable are deducted.

Funds Held - Directly Managed

Funds held - directly managed, where we receive the underlying return on the investment portfolio, are carried at fair value, either because we elected the fair value option at the inception of the reinsurance contract, or because it represents the aggregate of funds held at amortized cost and the fair value of an embedded derivative. The embedded derivative relates to our contractual right to receive the return on the underlying investment portfolio supporting the reinsurance contract. We include the estimated fair value of these embedded derivatives in the consolidated balance sheets with the host contract in order to reflect the expected settlement of these features with the host contract. The change in the fair value of the embedded derivative is included in net unrealized gains (losses). The following table summarizes the components of the funds held - directly managed:



	March 31, 2020		December 31, 2019
Fixed maturity investments, trading	$	1,081,629	$	1,173,345
Cash and cash equivalents	51,209		10,296
Other assets	2,083		3,911
	$	1,134,921	$	1,187,552

The following table summarizes the fixed maturity investment components of funds held - directly managed:



	March 31, 2020						December 31, 2019
	Funds held - Directly Managed - Fair Value Option		Funds held - Directly Managed - Variable Return		Total		Funds held - Directly Managed - Fair Value Option		Funds held - Directly Managed - Variable Return		Total
Fixed maturity investments, at amortized cost	$	164,425	$	895,214	$	1,059,639	$	185,859	$	940,194	$	1,126,053
Net unrealized gains (losses):
Change in fair value - fair value option accounting	2,754				2,754		5,438		—		5,438
Change in fair value - embedded derivative accounting			19,236		19,236		—		41,854		41,854
Fixed maturity investments within funds held - directly managed, at fair value	$	167,179	$	914,450	$	1,081,629	$	191,297	$	982,048	$	1,173,345

Refer to the sections above for details of the fixed maturity investments within our funds held - directly managed portfolios.

Funds Held by Reinsured Companies

Funds held by reinsured companies, where we received a fixed crediting rate, are carried at cost on our consolidated balance sheets. As of March 31, 2020 and December 31, 2019, we had funds held by reinsured companies of $827.4 million and $408.7 million, respectively. The increase related to $465.0 million of consideration for the Lyft transaction which was subsequently received in April 2020.

Net Investment Income

Major categories of net investment income are summarized as follows:



	Three Months Ended March 31,
	2020			2019
Fixed maturity investments	$	57,195		$	58,070
Short-term investments and cash and cash equivalents	2,794			3,860
Funds held	271			5,798
Funds held - directly managed	8,816			9,750
Investment income from fixed maturities and cash and cash equivalents	69,076			77,478
Equity investments	5,963			3,380
Other investments	7,505			2,114
Investment income from equities and other investments	13,468			5,494
Gross investment income	82,544			82,972
Investment expenses	(4,704		)	(4,276		)
Net investment income	$	77,840		$	78,696

Net Realized and Unrealized Gains (Losses)

Components of net realized and unrealized gains (losses) were as follows:



	Three Months Ended
	March 31,
	2020			2019
Net realized gains (losses) on sale:
Gross realized gains on fixed maturity securities, AFS	$	1,814		$	4
Gross realized losses on fixed maturity securities, AFS	(2,026		)	(65		)
Credit loss on fixed maturity securities, AFS	(13,212		)	—
Net realized gains (losses) on fixed maturity securities, trading	15,837			(611		)
Net realized gains (losses) on funds held - directly managed	512			(1,606		)
Net realized gains (losses) on equity investments	(1,007		)	2,548
Total net realized gains on sale	$	1,918		$	270
Net unrealized gains (losses):
Fixed maturity securities, trading	$	(261,008	)	$	209,467
Fixed maturity securities in funds held - directly managed portfolios	(25,302		)	38,962
Equity investments	(91,952		)	7,383
Other Investments	(258,132		)	204,709
Total net unrealized gains (losses)	(636,394		)	460,521
Net realized and unrealized gains (losses)	$	(634,476	)	$	460,791

The gross realized gains and losses on AFS investments included in the table above resulted from sales of $388.8 million and $1.2 million for the three months ended March 31, 2020 and 2019, respectively.

Restricted Assets

We utilize trust accounts to collateralize business with our insurance and reinsurance counterparties. We are also required to maintain investments and cash and cash equivalents on deposit with regulatory authorities and Lloyd's to support our insurance and reinsurance operations. The investments and cash and cash equivalents on deposit are available to settle insurance and reinsurance liabilities. Collateral generally takes the form of assets held in trust, letters of credit or funds held. The assets used as collateral are primarily highly rated fixed maturity securities. The carrying value of our restricted assets, including restricted cash of $345.1 million and $352.7 million, as of March 31, 2020 and December 31, 2019, respectively, was as follows:



	March 31, 2020		December 31, 2019
Collateral in trust for third party agreements	$	3,664,247	$	4,104,093
Assets on deposit with regulatory authorities	226,477		445,626
Collateral for secured letter of credit facilities	124,505		133,238
Funds at Lloyd's ⁽¹⁾	717,970		639,316
	$	4,733,199	$	5,322,273

⁽¹⁾Our businesses include three Lloyd's syndicates. Lloyd's determines the required capital principally through the annual business plan of each syndicate. This capital is referred to as "Funds at Lloyd's" and will be drawn upon in the event that a syndicate has a loss that cannot be funded from other sources. We also utilize unsecured letters of credit for Funds at Lloyd's, as described in Note 13 - "Debt Obligations and Credit Facilities."

Derivative and Hedging Instruments

3 Months Ended

Mar. 31, 2020

Derivative Instruments and Hedging Activities Disclosure [Abstract]

DERIVATIVE AND HEDGING INSTRUMENTS

5. DERIVATIVES AND HEDGING INSTRUMENTS

Foreign Currency Hedging of Net Investments in Foreign Operations

We use foreign currency forward exchange rate contracts in qualifying hedging relationships to hedge the foreign currency exchange rate risk associated with certain of our net investments in foreign operations. As of March 31, 2020 and December 31, 2019, we had forward currency contracts in place which we had designated as hedges of our net investments in foreign operations.

The following table presents the gross notional amounts and estimated fair values recorded within other assets and other liabilities related to our qualifying foreign currency forward exchange rate contracts:



	March 31, 2020						December 31, 2019
			Fair Value						Fair Value
	Gross Notional Amount		Assets		Liabilities		Gross Notional Amount		Assets		Liabilities
Foreign currency forward - AUD	$	56,149	$	4,269	$	—	$	64,620	$	52	$	2,033
Foreign currency forward - EUR	103,127		194		943		112,284		246		1,635
Foreign currency forward - GBP	297,582		13,192		—		318,387		344		7,784
Total qualifying hedges	$	456,858	$	17,655	$	943	$	495,291	$	642	$	11,452

The following table presents the amounts of the net gains and losses deferred in the cumulative translation adjustment ("CTA") account, which is a component of accumulated other comprehensive income (loss) ("AOCI"), in shareholders' equity, relating to our foreign currency forward exchange rate contracts:



	Amount of Gains (Losses) Deferred in AOCI
	Three Months Ended March 31,
	2020		2019
Foreign currency forward - AUD	$	8,471	$	(327	)
Foreign currency forward - EUR	2,635		1,855
Foreign currency forward - GBP	20,812		—
Net gains on qualifying derivative hedges	$	31,918	$	1,528

Derivatives Not Designated or Not Qualifying as Hedging Instruments

From time to time, we may also utilize foreign currency forward contracts as part of our overall foreign currency risk management strategy or to obtain exposure to a particular financial market, as well as for yield enhancement in non-qualifying hedging relationships. We may also utilize equity call option instruments either to obtain exposure to a particular equity instrument or for yield enhancement in non-qualifying hedging relationships.

Foreign Currency Forward Contracts

The following table presents the gross notional amounts and estimated fair values recorded within other assets and other liabilities related to our non-qualifying foreign currency forward hedging relationships:



	March 31, 2020						December 31, 2019
			Fair Value						Fair Value
	Gross Notional Amount		Assets		Liabilities		Gross Notional Amount		Assets		Liabilities
Foreign currency forward - AUD	$	32,103	$	3,088	$	608	$	913	$	839	$	892
Foreign currency forward - CAD	50,754		3,419		1		66,266		10		1,482
Foreign currency forward - EUR	52,660		173		1,672		74,444		507		1,440
Foreign currency forward - GBP	24,427		972		713		11,940		13		292
Total non-qualifying hedges	$	159,944	$	7,652	$	2,994	$	153,563	$	1,369	$	4,106

The following table presents the amounts of the net gains (losses) included in earnings related to our non-qualifying foreign currency forward contracts:



	Gains (Losses) on non-qualifying-hedges included in net earnings
	Three Months Ended March 31,
	2020		2019
Foreign currency forward - AUD	$	2,533	$	(765	)
Foreign currency forward - CAD	4,996		1
Foreign currency forward - EUR	1,176		1,205
Foreign currency forward - GBP	576		(4,059		)
Net gains (losses) on non-qualifying hedges	$	9,281	$	(3,618	)

Investments in Call Options on Equities

During the three months ended March 31, 2020 and 2019, we recorded unrealized losses of less than $0.1 million and $0.2 million, respectively, in net earnings on the call options on equities that we purchased in 2018 at a cost of $10.0 million. These call options on equities, which had a fair value of less than $0.1 million as of December 31, 2019, expired without being exercised during the three months ended March 31, 2020.

Other Derivatives

In October 2019, we entered into a forward interest rate swap, with a notional amount of AUD$120.0 million, to partially mitigate the risk associated with declining interest rates until the completion of the Munich Re transaction, as discussed in Note 3 - "Significant New Business", which is expected to close in the third quarter of 2020. The carrying value of the forward interest rate swap, recorded in other assets, was $0.5 million as of March 31, 2020 compared to $0.3 million recorded in other liabilities as of December 31, 2019. We recorded unrealized gains in net earnings of $0.8 million on the instrument for the three months ended March 31, 2020. This forward interest rate swap was subsequently terminated on April 7, 2020, for an inception-to-date gain of $0.5 million.

Reinsurance Balances Recoverable on Paid and Unpaid Losses

3 Months Ended

Mar. 31, 2020

Insurance [Abstract]

REINSURANCE BALANCES RECOVERABLE ON PAID AND UNPAID LOSSES

6. REINSURANCE BALANCES RECOVERABLE ON PAID AND UNPAID LOSSES

The following tables provide the total reinsurance balances recoverable on paid and unpaid losses:



	March 31, 2020
	Non-life Run-off			Atrium		StarStone			Total
Recoverable from reinsurers on unpaid:
Outstanding losses	$	957,961		$	8,140	$	321,921		$	1,288,022
IBNR	602,508			24,781		263,222			890,511
Fair value adjustments - acquired companies	(13,353		)	514		(1,678		)	(14,517		)
Fair value adjustments - fair value option	(93,935		)	—		—			(93,935		)
ULAE	7,827			—		—			7,827
Total reinsurance reserves recoverable	1,461,008			33,435		583,465			2,077,908
Paid losses recoverable	137,210			1,181		103,478			241,869
Total	$	1,598,218		$	34,616	$	686,943		$	2,319,777

Reconciliation to Consolidated Balance Sheet:
Reinsurance balances recoverable on paid and unpaid losses	$	944,822		$	34,616	$	686,943		$	1,666,381
Reinsurance balances recoverable on paid and unpaid losses - fair value option	653,396			—		—			653,396
Total	$	1,598,218		$	34,616	$	686,943		$	2,319,777



	December 31, 2019
	Non-life Run-off			Atrium		StarStone			Total
Recoverable from reinsurers on unpaid:
Outstanding losses	$	972,293		$	9,011	$	328,009		$	1,309,313
IBNR	673,059			19,286		211,404			903,749
Fair value adjustments - acquired companies	(13,652		)	519		(2,122		)	(15,255		)
Fair value adjustments - fair value option	(88,086		)	—		—			(88,086		)
Total reinsurance reserves recoverable	1,543,614			28,816		537,291			2,109,721
Paid losses recoverable	181,375			1,541		87,253			270,169
Total	$	1,724,989		$	30,357	$	624,544		$	2,379,890

Reconciliation to Consolidated Balance Sheet:
Reinsurance balances recoverable on paid and unpaid losses	$	1,029,471		$	30,357	$	624,544		$	1,684,372
Reinsurance balances recoverable on paid and unpaid losses - fair value option	695,518			—		—			695,518
Total	$	1,724,989		$	30,357	$	624,544		$	2,379,890

Our insurance and reinsurance run-off subsidiaries and assumed portfolios, prior to acquisition, used retrocessional agreements to reduce their exposure to the risk of insurance and reinsurance assumed. On an annual basis, both Atrium and StarStone purchase a tailored outwards reinsurance program designed to manage their risk profiles. The majority of Atrium’s and StarStone's third-party reinsurance cover is with highly rated reinsurers or is collateralized by pledged assets or letters of credit.

The fair value adjustments, determined on acquisition of insurance and reinsurance subsidiaries, are based on the estimated timing of loss and LAE recoveries and an assumed interest rate equivalent to a risk free rate for securities with similar duration to the acquired reinsurance balances recoverable on paid and unpaid losses plus a spread for credit risk, and are amortized over the estimated recovery period, as adjusted for accelerations in timing of payments as a result of commutation settlements. The determination of the fair value adjustments on the retroactive reinsurance contracts for which we have elected the fair value option is described in Note 10 - "Fair Value Measurements."

As of March 31, 2020 and December 31, 2019, we had reinsurance balances recoverable on paid and unpaid losses of $2.3 billion and $2.4 billion, respectively. The decrease of $60.1 million in reinsurance balances recoverable on paid and unpaid losses was primarily due to cash collections in the first three months of 2020, offset by reserve increases on StarStone, which includes estimated recoverables on losses related to the COVID-19 pandemic.

Top Ten Reinsurers



	March 31, 2020
	Non-life Run-off		Atrium		StarStone		Total		% of Total
Top 10 reinsurers	$	1,075,150	$	25,328	$	430,788	$	1,531,266	66.0	%
Other reinsurers > $1 million	510,504		8,742		253,127		772,373		33.3	%
Other reinsurers < $1 million	12,564		546		3,028		16,138		0.7	%
Total	$	1,598,218	$	34,616	$	686,943	$	2,319,777	100.0	%



	December 31, 2019
	Non-life Run-off		Atrium		StarStone		Total		% of Total
Top 10 reinsurers	$	1,154,110	$	22,051	$	388,171	$	1,564,332	65.7	%
Other reinsurers > $1 million	551,636		7,761		233,871		793,268		33.4	%
Other reinsurers < $1 million	19,243		545		2,502		22,290		0.9	%
Total	$	1,724,989	$	30,357	$	624,544	$	2,379,890	100.0	%



	March 31, 2020		December 31, 2019
Information regarding top ten reinsurers:
Number of top 10 reinsurers rated A- or better	8		8
Number of top 10 non-rated reinsurers ⁽¹⁾	2		2

Reinsurers rated A- or better in top 10	$	1,260,977	$	1,292,207
Collaterized non-rated reinsurers in top 10 ⁽¹⁾	270,289		272,125
Total top 10 reinsurance recoverables	$	1,531,266	$	1,564,332

Single reinsurers that represent 10% or more of total reinsurance balance recoverables as of March 31, 2020:

Hannover Ruck SE ⁽²⁾	$	264,424	$	261,295
Lloyd's Syndicates ⁽³⁾	$	412,790	$	411,030

⁽¹⁾For the two non-rated reinsurers as of March 31, 2020 and two non-rated reinsurers as of December 31, 2019, we hold security in the form of pledged assets in trust or letters of credit issued to us in the full amount of the recoverable.

⁽²⁾ Hannover Ruck SE is rated AA- by Standard & Poor’s and A+ by A.M. Best.

⁽³⁾ Lloyd's Syndicates are rated A+ by Standard & Poor's and A by A.M. Best.

Allowance for Estimated Uncollectible Reinsurance Balances Recoverable on Paid and Unpaid Losses

We evaluate and monitor the credit risk related to our reinsurers, and an allowance for estimated uncollectible reinsurance balances recoverable on paid and unpaid losses ("allowance for estimated uncollectible reinsurance") is established for amounts considered potentially uncollectible.

With respect to our process for determining the allowances for estimated uncollectible reinsurance, we adopted ASU 2016-13 and the related amendments on January 1, 2020 and recorded a cumulative effect adjustment of $0.2 million to increase the opening retained earnings on the initial adoption of the guidance. Our allowance for estimated uncollectible reinsurance is derived based on various data sources, multiple key inputs and forecast scenarios. These include the duration of the collection period, credit quality, changes in reinsurer credit standing, default rates specific

to the individual reinsurer, the geographical location of the reinsurer, contractual disputes with reinsurers over individual contentious claims, contract language or coverage issues, industry analyst reports and consensus economic forecasts.

To determine the allowance for estimated uncollectible reinsurance, we use the PD and LGD methodology whereby each reinsurer is allocated an appropriate PD percentage based on the expected payout duration by portfolio. This PD percentage is then multiplied by an appropriate LGD percentage to arrive at an overall credit allowance percentage which is then applied to the reinsurance balance recoverable for each reinsurer, net of any specific bad debt provisions, collateral or other contract related offsets, to arrive at the overall allowance for estimated uncollectible reinsurance by reinsurer.

The following tables show our gross and net balances recoverable from our reinsurers as well as the related allowance for estimated uncollectible reinsurance broken down by the credit ratings of our reinsurers. The majority of the allowance for estimated uncollectible reinsurance relates to the Non-life Run-off segment.



	March 31, 2020
	Gross		Allowance for estimated uncollectible reinsurance		Net		Provisions as a % of Gross
Reinsurers rated A- or above	$	1,853,658	$	42,759	$	1,810,899	2.3	%
Reinsurers rated below A-, secured	478,752		—		478,752		—	%
Reinsurers rated below A-, unsecured	130,694		100,568		30,126		76.9	%
Total	$	2,463,104	$	143,327	$	2,319,777	5.8	%



	December 31, 2019
	Gross		Allowance for estimated uncollectible reinsurance		Net		Provisions as a % of Gross
Reinsurers rated A- or above	$	1,904,268	$	43,427	$	1,860,841	2.3	%
Reinsurers rated below A-, secured	487,608		—		487,608		—	%
Reinsurers rated below A-, unsecured	135,653		104,212		31,441		76.8	%
Total	$	2,527,529	$	147,639	$	2,379,890	5.8	%

The table below provides a reconciliation of the beginning and ending allowance for estimated uncollectible reinsurance balances for the three months ended March 31, 2020:



	Three Months Ended
	March 31, 2020
Allowance for estimated uncollectible reinsurance, beginning of period	$	147,639
Cumulative effect of change in accounting principle	(195		)
Current period change in the allowance	(4,117		)
Allowance for estimated uncollectible reinsurance, end of period	$	143,327

During the three months ended March 31, 2020, we did not have any write-offs charged against the allowance for estimated uncollectible reinsurance or any recoveries of amounts previously written off.

The change in the allowance for estimated uncollectible reinsurance during the three months ended March 31, 2020 was purely attributable to the weakening of the Australian dollar and the British pound sterling against the U.S. dollar, which is our functional currency. While the allowances in original currency did not change, the weakening of those currencies against the U.S. dollar resulted in an overall reduction in the allowance during the three months ended March 31, 2020.

11. PREMIUMS WRITTEN AND EARNED

The following table provides a summary of premiums written and earned by segment and for our other activities:



	Three Months Ended March 31,
	2020						2019
	Premiums Written			Premiums Earned			Premiums Written			Premiums Earned
Non-life Run-off
Gross	$	327		$	18,078		$	(20,877	)	$	83,966
Ceded	1,849			(2,048		)	1,699			(7,292		)
Net	$	2,176		$	16,030		$	(19,178	)	$	76,674
Atrium
Gross	$	57,837		$	47,833		$	53,985		$	43,386
Ceded	(9,139		)	(5,463		)	(7,486		)	(4,633		)
Net	$	48,698		$	42,370		$	46,499		$	38,753
StarStone
Gross	$	279,854		$	258,107		$	251,373		$	268,264
Ceded	(90,819		)	(59,947		)	(56,772		)	(55,002		)
Net	$	189,035		$	198,160		$	194,601		$	213,262
Other
Gross	$	(3,885	)	$	2,673		$	864		$	6,673
Ceded	664			664			(19		)	(75		)
Net	$	(3,221	)	$	3,337		$	845		$	6,598
Total
Gross	$	334,133		$	326,691		$	285,345		$	402,289
Ceded	(97,445		)	(66,794		)	(62,578		)	(67,002		)
Total	$	236,688		$	259,897		$	222,767		$	335,287

Gross premiums written for the three months ended March 31, 2020 and 2019 were $334.1 million and $285.3 million, respectively, an increase of $48.8 million. The increase was primarily due to an increase in gross premiums written in our StarStone and Non-life Run-off segments of $28.5 million and $21.2 million, respectively. The increase in the StarStone segment was primarily driven by an increase in the casualty lines of business, due to new business opportunities and improving rates, as well as an increase in the aerospace line of business, as a result of a new proportional quota share arrangement. These increases were partially offset by decreases in StarStone's property and marine lines of business as a result of our strategy to exit certain lines of business and to focus on core lines. The negative gross premium written in the Non-Life Run-off segment for the three months ended March 31, 2019 related to premium adjustments on the acquired unearned premium.

Deferred Charge Assets

3 Months Ended

Mar. 31, 2020

Insurance [Abstract]

DEFERRED CHARGE ASSETS

7. DEFERRED CHARGE ASSETS

Deferred charge assets relate to retroactive reinsurance policies providing indemnification of losses and LAE with respect to past loss events in the Non-life Run-off segment. For insurance and reinsurance contracts for which we do not elect the fair value option, a deferred charge asset is recorded for the excess, if any, of the estimated ultimate losses payable over the premiums received at the initial measurement. The premium consideration that we charge the ceding companies may be lower than the undiscounted estimated ultimate losses payable due to the time value of money. After receiving the premium consideration in full from our cedents at the inception of the contract, we invest the premium received over an extended period of time thereby generating investment income. We expect to generate profits from these retroactive reinsurance policies when taking into account the premium received and expected investment income, less contractual obligations and expenses.

Deferred charge assets are included in other assets on our consolidated balance sheets. The following table presents a reconciliation of the deferred charge assets:



	Three Months Ended March 31,
	2020			2019
Beginning carrying value	$	272,462		$	86,585
Recorded during the period	—			20,632
Amortization	(14,630		)	(7,063		)
Ending carrying value	$	257,832		$	100,154

Deferred charge assets are amortized over the estimated claim payment period of the related contract with the periodic amortization reflected in earnings as a component of losses and LAE. Deferred charge assets amortization is adjusted at each reporting period to reflect new estimates of the amount and timing of remaining loss payments. Changes in the estimated amount and the timing of payments of unpaid losses may have an effect on the unamortized deferred charge assets and the amount of periodic amortization. Deferred charge assets are assessed at each reporting period for impairment. If the asset is determined to be impaired, it is written down in the period in which the determination is made. For the three months ended March 31, 2020, we completed our assessment for impairment of deferred charge assets and concluded that there had been no impairment of our carried deferred charge assets amount.

Losses and Loss Adjustment Expenses

3 Months Ended

Mar. 31, 2020

Insurance [Abstract]

LOSSES AND LOSS ADJUSTMENT EXPENSES

8. LOSSES AND LOSS ADJUSTMENT EXPENSES

The liability for losses and loss adjustment expenses ("LAE"), also referred to as loss reserves, represents our gross estimates before reinsurance for unpaid reported losses and includes losses that have been incurred but not reported ("IBNR") for our Non-life Run-off, Atrium and StarStone segments using a variety of actuarial methods. We recognize an asset for the portion of the liability that we expect to recover from reinsurers. LAE reserves include allocated loss adjustment expenses ("ALAE"), and unallocated loss adjustment expenses ("ULAE"). ALAE are linked to the settlement of an individual claim or loss, whereas ULAE are based on our estimates of future costs to administer the claims. IBNR represents reserves for loss and LAE that have been incurred but not yet reported to us. This includes amounts for unreported claims, development on known claims and reopened claims.

Our loss reserves cover multiple lines of business, which include asbestos, environmental, general casualty, workers' compensation/personal accident, marine, aviation and transit, construction defect, professional indemnity/directors and officers, motor, property and other non-life lines of business. Refer to Note 10 - "Losses and Loss Adjustment Expenses" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019 for more information on establishing the liability for losses and LAE.

The following tables summarize the liability for losses and LAE by segment and for our other activities:



	March 31, 2020
	Non-life Run-off			Atrium		StarStone			Other		Total
Outstanding losses	$	4,392,560		$	86,712	$	831,996		$	9,764	$	5,321,032
IBNR	3,937,751			150,666		1,086,293			12,749		5,187,459
Fair value adjustments - acquired companies	(161,040		)	3,833		(413		)	—		(157,620		)
Fair value adjustments - fair value option	(274,642		)	—		—			—		(274,642		)
ULAE	322,221			2,399		29,138			—		353,758
Total	$	8,216,850		$	243,610	$	1,947,014		$	22,513	$	10,429,987

Reconciliation to Consolidated Balance Sheet:
Loss and loss adjustment expenses	$	5,871,307		$	243,610	$	1,947,014		$	22,513	$	8,084,444
Loss and loss adjustment expenses, at fair value	2,345,543			—		—			—		2,345,543
Total	$	8,216,850		$	243,610	$	1,947,014		$	22,513	$	10,429,987



	December 31, 2019
	Non-life Run-off			Atrium		StarStone			Other		Total
Outstanding losses	$	4,407,082		$	89,141	$	888,794		$	9,512	$	5,394,529
IBNR	3,945,407			136,543		962,353			13,565		5,057,868
Fair value adjustments - acquired companies	(170,689		)	3,700		(522		)	—		(167,511		)
Fair value adjustments - fair value option	(217,933		)	—		—			—		(217,933		)
ULAE	331,494			2,288		28,503			—		362,285
Total	$	8,295,361		$	231,672	$	1,879,128		$	23,077	$	10,429,238

Reconciliation to Consolidated Balance Sheet:
Loss and loss adjustment expenses	$	5,674,239		$	231,672	$	1,879,128		$	23,077	$	7,808,116
Loss and loss adjustment expenses, at fair value	2,621,122			—		—			—		2,621,122
Total	$	8,295,361		$	231,672	$	1,879,128		$	23,077	$	10,429,238

The overall increase in the liability for losses and LAE between December 31, 2019 and March 31, 2020 was primarily attributable to the Lyft reinsurance transaction, as described in Note 3 - "Significant New Business" and net incurred losses and LAE in the period, partially offset by losses paid and foreign exchange gains in the period.

The table below provides a consolidated reconciliation of the beginning and ending liability for losses and LAE:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	10,429,238		$	9,409,504
Less: reinsurance reserves recoverable	2,109,721			1,867,841
Less: deferred charge assets on retroactive reinsurance	272,462			86,585
Less: cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible reinsurance balances ⁽¹⁾	195			—
Net balance as of beginning of period	8,046,860			7,455,078
Net incurred losses and LAE:
Current period	181,203			217,266
Prior periods	(73,309		)	95,138
Total net incurred losses and LAE	107,894			312,404
Net paid losses:
Current period	(6,582		)	(28,029		)
Prior periods	(378,992		)	(461,605		)
Total net paid losses	(385,574		)	(489,634		)
Effect of exchange rate movement	(146,083		)	19,679
Assumed business	471,150			620,418
Net balance as of March 31	8,094,247			7,917,945
Plus: reinsurance reserves recoverable⁽²⁾	2,077,908			2,077,923
Plus: deferred charge assets on retroactive reinsurance	257,832			100,154
Balance as of March 31	$	10,429,987		$	10,096,022

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible reinsurance.

The tables below provide the components of net incurred losses and LAE by segment and for our other activities:



	Three Months Ended March 31, 2020
	Non-life Run-off			Atrium		StarStone			Other			Total
Net losses paid	$	258,966		$	17,008	$	106,554		$	3,046		$	385,574
Net change in case and LAE reserves	(174,580		)	139		(43,192		)	252			(217,381		)
Net change in IBNR reserves	(104,397		)	11,131		75,262			(816		)	(18,820		)
Increase (reduction) in estimates of net ultimate losses	(20,011		)	28,278		138,624			2,482			149,373
Increase (reduction) in provisions for unallocated LAE	(7,479		)	—		741			—			(6,738		)
Amortization of deferred charge assets	14,630			—		—			—			14,630
Amortization of fair value adjustments	9,063			138		(335		)	—			8,866
Changes in fair value - fair value option	(58,237		)	—		—			—			(58,237		)
Net incurred losses and LAE	$	(62,034	)	$	28,416	$	139,030		$	2,482		$	107,894



	Three Months Ended March 31, 2019
	Non-life Run-off			Atrium			StarStone			Other		Total
Net losses paid	$	349,069		$	22,313		$	115,417		$	2,835	$	489,634
Net change in case and LAE reserves	(77,701		)	(413		)	2,056			595		(75,463		)
Net change in IBNR reserves	(232,895		)	(5,817		)	76,424			1,526		(160,762		)
Increase in estimates of net ultimate losses	38,473			16,083			193,897			4,956		253,409
Increase (reduction) in provisions for unallocated LAE	(15,175		)	—			1,348			—		(13,827		)
Amortization of deferred charge assets	7,064			—			—			—		7,064
Amortization of fair value adjustments	8,779			1,131			(193		)	—		9,717
Changes in fair value - fair value option	56,041			—			—			—		56,041
Net incurred losses and LAE	$	95,182		$	17,214		$	195,052		$	4,956	$	312,404

Non-life Run-off Segment

The table below provides a reconciliation of the beginning and ending liability for losses and LAE for the Non-life Run-off segment:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	8,295,361		$	7,540,662
Less: reinsurance reserves recoverable	1,543,614			1,366,123
Less: deferred charge assets on retroactive insurance	272,462			86,585
Plus: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance ⁽¹⁾	703			—
Net balance as of beginning of period	6,479,988			6,087,954
Net incurred losses and LAE:
Current period	7,849			49,071
Prior periods	(69,883		)	46,111
Total net incurred losses and LAE	(62,034		)	95,182
Net paid losses:
Current period	(1,240		)	(18,014		)
Prior periods	(257,726		)	(331,055		)
Total net paid losses	(258,966		)	(349,069		)
Effect of exchange rate movement	(132,128		)	20,689
Assumed business	471,150			620,418
Net balance as of March 31	6,498,010			6,475,174
Plus: reinsurance reserves recoverable ⁽²⁾	1,461,008			1,579,646
Plus: deferred charge assets on retroactive reinsurance	257,832			100,154
Balance as of March 31	$	8,216,850		$	8,154,974

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible reinsurance.

Net incurred losses and LAE in the Non-life Run-off segment were as follows:



	Three Months Ended March 31,
	2020								2019
	Prior Period			Current Period		Total			Prior Period			Current Period		Total
Net losses paid	$	257,726		$	1,240	$	258,966		$	331,055		$	18,014	$	349,069
Net change in case and LAE reserves	(176,252		)	1,672		(174,580		)	(97,573		)	19,872		(77,701		)
Net change in IBNR reserves	(109,334		)	4,937		(104,397		)	(243,815		)	10,920		(232,895		)
Increase (reduction) in estimates of net ultimate losses	(27,860		)	7,849		(20,011		)	(10,333		)	48,806		38,473
Increase (reduction) in provisions for unallocated LAE	(7,479		)	—		(7,479		)	(15,440		)	265		(15,175		)
Amortization of deferred charge assets	14,630			—		14,630			7,064			—		7,064
Amortization of fair value adjustments	9,063			—		9,063			8,779			—		8,779
Changes in fair value - fair value option	(58,237		)	—		(58,237		)	56,041			—		56,041
Net incurred losses and LAE	$	(69,883	)	$	7,849	$	(62,034	)	$	46,111		$	49,071	$	95,182

Net change in case and LAE reserves comprises the movement during the period in specific case reserve liabilities as a result of claims settlements or changes advised to us by our policyholders and attorneys, less changes in case reserves recoverable advised by us to our reinsurers as a result of the settlement or movement of assumed claims. Net change in IBNR represents the gross change in our actuarial estimates of IBNR, less amounts recoverable.

Three Months Ended March 31, 2020

The reduction in net incurred losses and LAE for the three months ended March 31, 2020 of $62.0 million included net incurred losses and LAE of $7.8 million related to current period net earned premium, primarily in respect of the run-off business acquired with the AmTrust RITC transactions. Excluding current period net incurred losses and LAE of $7.8 million, the reduction in net incurred losses and LAE liabilities relating to prior periods was $69.9 million, which was attributable to a reduction in estimates of net ultimate losses of $27.9 million, a reduction in the fair value of liabilities of $58.2 million related to our assumed retroactive reinsurance agreements for which we have elected the fair value option and a reduction in provisions for unallocated LAE of $7.5 million relating to 2020 run-off activity, partially offset by amortization of fair value adjustments over the estimated payout period relating to companies acquired of $9.1 million and amortization of the deferred charge assets of $14.6 million. The reduction in estimates of net ultimate losses relating to prior periods of $27.9 million for the three months ended March 31, 2020 included a net reduction in case and IBNR reserves of $285.6 million, partially offset by net losses paid of $257.7 million.

Three Months Ended March 31, 2019

Net incurred losses and LAE for the three months ended March 31, 2019 of $95.2 million included net incurred losses and LAE of $49.1 million related to current period net earned premium, primarily due to the run-off business acquired in connection with the AmTrust RITC transactions and the acquisition of Maiden Reinsurance North America, Inc. ("Maiden Re North America"). Excluding current period net incurred losses and LAE of $49.1 million, the increase in net incurred losses and LAE liabilities relating to prior periods was $46.1 million, which was attributable to an increase in the fair value of liabilities of $56.0 million related to our assumed retroactive reinsurance agreements for which we have elected the fair value option, amortization of fair value adjustments over the estimated payout period relating to companies acquired of $8.8 million and the amortization of the deferred charge assets of $7.1 million, partially offset by a reduction in estimates of net ultimate losses of $10.3 million and a reduction in provisions for unallocated LAE of $15.4 million relating to 2019 run-off activity. The reduction in estimates of net ultimate losses of $10.3 million for the three months ended March 31, 2019 included a net reduction in case and IBNR reserves of $341.4 million, partially offset by net losses paid of $331.1 million.

Atrium

The table below provides a reconciliation of the beginning and ending liability for losses and LAE for the Atrium segment:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	231,672		$	241,284
Less: reinsurance reserves recoverable	28,816			38,768
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance ⁽¹⁾	851			—
Net balance as of beginning of period	202,005			202,516
Net incurred losses and LAE:
Current period	27,904			18,237
Prior periods	512			(1,023		)
Total net incurred losses and LAE	28,416			17,214
Net paid losses:
Current period	(4,285		)	(7,893		)
Prior periods	(12,723		)	(14,420		)
Total net paid losses	(17,008		)	(22,313		)
Effect of exchange rate movement	(3,238		)	281
Net balance as of March 31	210,175			197,698
Plus: reinsurance reserves recoverable ⁽²⁾	33,435			31,682
Balance as of March 31	$	243,610		$	229,380

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible reinsurance.

Net incurred losses and LAE in the Atrium segment were as follows:



	Three Months Ended March 31,
	2020							2019
	Prior Period			Current Period		Total		Prior Period			Current Period		Total
Net losses paid	$	12,723		$	4,285	$	17,008	$	14,420		$	7,893	$	22,313
Net change in case and LAE reserves	(3,034		)	3,173		139		(6,342		)	5,929		(413		)
Net change in IBNR reserves	(9,315		)	20,446		11,131		(10,232		)	4,415		(5,817		)
Increase (reduction) in estimates of net ultimate losses	374			27,904		28,278		(2,154		)	18,237		16,083
Amortization of fair value adjustments	138			—		138		1,131			—		1,131
Net incurred losses and LAE	$	512		$	27,904	$	28,416	$	(1,023	)	$	18,237	$	17,214

Three Months Ended March 31, 2020 and 2019

Net incurred losses and LAE for the three months ended March 31, 2020 and 2019 were $28.4 million and $17.2 million, respectively. Net unfavorable prior period loss development was $0.5 million for the three months ended March 31, 2020 compared to net favorable prior period development of $1.0 million for the three months ended March 31, 2019. The current period net unfavorable prior period loss development was driven by reserve strengthening for the construction loss. Excluding prior period loss development, net incurred losses and LAE for the three months ended March 31, 2020 were $27.9 million and included $8.6 million of losses related to the COVID-19 pandemic. Excluding prior period loss development, net incurred losses and LAE for the three months ended March 31, 2019 were $18.2 million.

StarStone

The table below provides a reconciliation of the beginning and ending liability for losses and LAE for our StarStone segment:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	1,879,128		$	1,608,697
Less: reinsurance reserves recoverable	537,291			462,950
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance ⁽¹⁾	47			—
Net balance as of beginning of period	1,341,790			1,145,747
Net incurred losses and LAE:
Current period	142,105			144,950
Prior periods	(3,075		)	50,102
Total net incurred losses and LAE	139,030			195,052
Net paid losses:
Current period	(1,027		)	(1,792		)
Prior periods	(105,527		)	(113,625		)
Total net paid losses	(106,554		)	(115,417		)
Effect of exchange rate movement	(10,717		)	(1,291		)
Net balance as of March 31	1,363,549			1,224,091
Plus: reinsurance reserves recoverable ⁽²⁾	583,465			466,595
Balance as of March 31	$	1,947,014		$	1,690,686

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible reinsurance.

Net incurred losses and LAE in the StarStone segment were as follows:



	Three Months Ended March 31,
	2020								2019
	Prior Period			Current Period		Total			Prior Period			Current Period		Total
Net losses paid	$	105,527		$	1,027	$	106,554		$	113,625		$	1,792	$	115,417
Net change in case and LAE reserves	(48,693		)	5,501		(43,192		)	(8,824		)	10,880		2,056
Net change in IBNR reserves	(57,969		)	133,231		75,262			(52,834		)	129,258		76,424
Increase (reduction) in estimates of net ultimate losses	(1,135		)	139,759		138,624			51,967			141,930		193,897
Increase (reduction) in provisions for unallocated LAE	(1,605		)	2,346		741			(1,672		)	3,020		1,348
Amortization of fair value adjustments	(335		)	—		(335		)	(193		)	—		(193		)
Net incurred losses and LAE	$	(3,075	)	$	142,105	$	139,030		$	50,102		$	144,950	$	195,052

Three Months Ended March 31, 2020 and 2019

Net incurred losses and LAE for the three months ended March 31, 2020 and 2019 were $139.0 million and $195.1 million, respectively. Net favorable prior period loss development was $3.1 million for the three months ended March 31, 2020 compared to net unfavorable prior period loss development of $50.1 million for the three months ended March 31, 2019. Net favorable prior period loss development for the three months ended March 31, 2020 was primarily driven by favorable run-off across several lines of business. Net adverse prior period loss development for the three months ended March 31, 2019 was primarily related to development on lines of business which we have either exited or which are subject to remediation as part of our underwriting repositioning. Excluding prior period net loss development, net incurred losses and LAE for the three months ended March 31, 2020 were $142.1 million and included $32.1 million of losses related to the COVID-19 pandemic. Excluding prior period net loss development, net incurred losses and LAE for the three months ended March 31, 2019 were $145.0 million.

Defendant Asbestos and Environmental Liabilities

3 Months Ended

Mar. 31, 2020

Liability for Asbestos and Environmental Claims [Abstract]

DEFENDANT ASBESTOS AND ENVIRONMENTAL LIABILITIES

9. DEFENDANT ASBESTOS AND ENVIRONMENTAL LIABILITIES

We acquired DCo LLC ("DCo") on December 30, 2016, and Morse TEC on October 30, 2019, as described in Note 3 - "Acquisitions" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019. DCo and Morse TEC hold liabilities associated with personal injury asbestos claims and environmental claims arising from their legacy manufacturing operations. These companies continue to process asbestos personal injury claims in the normal course of business. Defendant asbestos liabilities on our consolidated balance sheets include amounts for loss payments and defense costs for pending and future asbestos-related claims, determined using standard actuarial techniques for asbestos exposures. Defendant environmental liabilities include estimated clean-up costs associated with the acquired companies' former operations based on engineering reports.

Insurance balances recoverable on our consolidated balance sheets include estimated insurance recoveries relating to these liabilities. The recorded asset represents our assessment of the capacity of the insurance agreements to indemnify our subsidiaries for the anticipated defense and loss payments for pending claims and projected future claims. The recognition of these recoveries is based on an assessment of the right to recover under the respective contracts and on the financial strength of the insurers. The recorded asset does not represent the limits of our insurance coverage, but rather the amount we would expect to recover if the accrued and projected loss and defense costs were paid in full.

Included within insurance balances recoverable and defendant asbestos and environmental liabilities are the fair value adjustments that were initially recognized upon acquisition. These fair value adjustments are amortized in proportion to the actual payout of claims and recoveries. The carrying value of the asbestos and environmental liabilities, insurance recoveries, future estimated expenses and the fair value adjustments related to DCo and Morse TEC as of March 31, 2020 and December 31, 2019 were as follows:



	March 31, 2020			December 31, 2019
Defendant asbestos and environmental liabilities:
Defendant asbestos liabilities	$	1,068,620		$	1,100,593
Defendant environmental liabilities	10,146			10,279
Estimated future expenses	49,607			51,637
Fair value adjustments	(305,657		)	(314,824		)
Defendant asbestos and environmental liabilities	822,716			847,685

Insurance balances recoverable:
Insurance recoveries related to defendant asbestos and environmental liabilities	532,653			549,593
Fair value adjustments	(97,040		)	(100,738		)
Insurance balances recoverable	435,613			448,855

Net liabilities relating to defendant asbestos and environmental exposures	$	387,103		$	398,830

The table below provides a consolidated reconciliation of the beginning and ending liability for defendant asbestos and environmental exposures for the three months ended March 31, 2020 and 2019:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	847,685		$	203,320
Less: Insurance balances recoverable	448,855			135,808
Plus: Cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible insurance balances ⁽¹⁾	3,167			—
Net balance as of beginning of period	401,997			67,512
Total net paid claims	6,581			2,751
Amounts recorded in other (income) expense:
Change in estimate of ultimate net liabilities	(24,915		)	(1,159		)
Increase (reduction) in estimated future expenses	(2,028		)	(2,125		)
Amortization of fair value adjustments	5,468			101
Total other expense (income)	(21,475		)	(3,183		)
Net balance as at March 31	387,103			67,080
Plus: Insurance balances recoverable ⁽²⁾	435,613			130,432
Balance as at March 31	$	822,716		$	197,512

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible insurance balances.

For further details on the methodologies used for determining liabilities, refer to Note 11 - "Defendant Asbestos and Environmental Liabilities" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019.

Allowance for Estimated Uncollectible Insurance Balances Recoverable on Defendant Asbestos Liabilities

We evaluate and monitor the credit risk related to our insurers and an allowance for estimated uncollectible insurance balances recoverable on our defendant asbestos liabilities ("allowance for estimated uncollectible insurance") is established for amounts considered potentially uncollectible.

With respect to our process for determining the allowances for estimated uncollectible insurance, we adopted ASU 2016-13 and the related amendments on January 1, 2020 and recorded a cumulative effect adjustment of $3.2 million to reduce the opening retained earnings on the initial adoption of the guidance. Our allowance for estimated uncollectible insurance is derived based on various data sources, multiple key inputs and forecast scenarios. These include the duration of the collection period, credit quality, changes in insurer credit standing, default rates specific to the individual insurer, the geographical location of the insurer, contractual disputes with insurers over individual contentious claims, contract language or coverage issues, industry analyst reports and consensus economic forecasts.

To determine the allowance for estimated uncollectible insurance, we similarly use the PD and LGD methodology as described in Note 6 - "Reinsurance Balances Recoverable on Paid and Unpaid Losses" above.

The table below provides a reconciliation of the beginning and ending allowance for estimated uncollectible insurance balances related to our defendant asbestos liabilities, for the three months ended March 31, 2020:



	Three Months Ended
	March 31, 2020
Allowance for estimated uncollectible insurance balances, beginning of period	$	3,818
Cumulative effect of change in accounting principle	3,167
Allowance for estimated uncollectible insurance balances, end of period	$	6,985

During the three months ended March 31, 2020, we did not recognize any changes to our allowance for estimated uncollectible insurance neither did we have any write-offs charged against the allowance nor any recoveries of amounts previously written off.

Fair Value Measurements

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

10. FAIR VALUE MEASUREMENTS

Fair Value Hierarchy

Fair value is defined as the price at which to sell an asset or transfer a liability (i.e. the "exit price") in an orderly transaction between market participants. We use a fair value hierarchy that gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data. The hierarchy is broken down into three levels as follows:


•	Level 1 - Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access. Valuation adjustments and block discounts are not applied to Level 1 instruments.


•	Level 2 - Valuations based on quoted prices in active markets for similar assets or liabilities, quoted prices for identical assets or liabilities in inactive markets, or for which significant inputs are observable (e.g. interest rates, yield curves, prepayment speeds, default rates, loss severities, etc.) or can be corroborated by observable market data.


•	Level 3 - Valuations based on unobservable inputs where there is little or no market activity. Unadjusted third party pricing sources or management's assumptions and internal valuation models may be used to determine the fair values.

In addition, certain of our other investments are measured at fair value using net asset value ("NAV") per share (or its equivalent) as a practical expedient and have not been classified within the fair value hierarchy above. We have categorized our assets and liabilities that are recorded at fair value on a recurring basis among levels based on the observability of inputs, or at fair value using NAV per share (or its equivalent) as follows:



	March 31, 2020
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value Based on NAV as Practical Expedient		Total Fair Value
Investments:
Short-term and fixed maturity investments:
U.S. government and agency	$	—	$	519,933	$	—	$	—	$	519,933
U.K. government	—		100,005		—		—		100,005
Other government	—		604,014		—		—		604,014
Corporate	—		5,538,691		—		—		5,538,691
Municipal	—		164,830		—		—		164,830
Residential mortgage-backed	—		467,918		—		—		467,918
Commercial mortgage-backed	—		873,504		—		—		873,504
Asset-backed	—		754,875		—		—		754,875
	$	—	$	9,023,770	$	—	$	—	$	9,023,770

Other assets included within funds held - directly managed	—		53,292		—		—		53,292

Equities:
Publicly traded equity investments	$	210,419	$	30,513	$	—	$	—	$	240,932
Exchange-traded funds	130,906		—		—		—		130,906
Privately held equity investments	—		—		270,012		—		270,012
	$	341,325	$	30,513	$	270,012	$	—	$	641,850

Other investments:
Hedge funds	$	—	$	—	$	—	$	1,055,448	$	1,055,448
Fixed income funds	—		325,066		—		138,651		463,717
Equity funds	—		76,591		—		243,455		320,046
Private equity funds	—		—		—		309,219		309,219
CLO equities	—		83,740		—		—		83,740
CLO equity funds	—		—		—		66,938		66,938
Private credit funds	—		—		—		20,473		20,473
Other	—		—		514		6,889		7,403
	$	—	$	485,397	$	514	$	1,841,073	$	2,326,984
Total Investments	$	341,325	$	9,592,972	$	270,526	$	1,841,073	$	12,045,896

Cash and cash equivalents	$	204,294	$	122,243	$	—	$	—	$	326,537

Reinsurance balances recoverable on paid and unpaid losses:	$	—	$	—	$	653,396	$	—	$	653,396

Other Assets:
Derivatives qualifying as hedges	$	—	$	17,655	$	—	$	—	$	17,655
Derivatives not qualifying as hedges	—		7,652		—		—		7,652
Derivative instruments	$	—	$	25,307	$	—	$	—	$	25,307

Losses and LAE:	$	—	$	—	$	2,345,543	$	—	$	2,345,543

Other Liabilities:
Derivatives qualifying as hedges	$	—	$	943	$	—	$	—	$	943
Derivatives not qualifying as hedges	—		2,994		—		—		2,994
Derivative instruments	$	—	$	3,937	$	—	$	—	$	3,937



	December 31, 2019
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value Based on NAV as Practical Expedient		Total Fair Value
Investments:
Short-term and fixed maturity investments:
U.S. government and agency	$	—	$	736,043	$	—	$	—	$	736,043
U.K government	—		161,772		—		—		161,772
Other government	—		702,857		—		—		702,857
Corporate	—		5,697,067		—		—		5,697,067
Municipal	—		167,882		—		—		167,882
Residential mortgage-backed	—		471,836		—		—		471,836
Commercial mortgage-backed	—		900,029		—		—		900,029
Asset-backed	—		775,402		—		—		775,402
	$	—	$	9,612,888	$	—	$	—	$	9,612,888

Other assets included within funds held - directly managed	$	—	$	14,207	$	—	$	—	$	14,207

Equities:
Publicly traded equity investments	$	297,310	$	30,565	$	—	$	—	$	327,875
Exchange-traded funds	133,047		—		—		—		133,047
Privately held equity investments	—		—		268,799		—		268,799
	$	430,357	$	30,565	$	268,799	$	—	$	729,721

Other investments:
Hedge funds	$	—	$	—	$	—	$	1,121,904	$	1,121,904
Fixed income funds	—		398,143		—		82,896		481,039
Equity funds	—		111,040		—		299,109		410,149
Private equity funds	—		—		—		329,885		329,885
CLO equities	—		—		87,555		—		87,555
CLO equity funds	—		—		—		87,509		87,509
Other	—		34		314		6,031		6,379
	$	—	$	509,217	$	87,869	$	1,927,334	$	2,524,420
Total Investments	$	430,357	$	10,166,877	$	356,668	$	1,927,334	$	12,881,236

Cash and cash equivalents	$	173,892	$	222,191	$	—	$	—	$	396,083

Reinsurance balances recoverable on paid and unpaid losses:	$	—	$	—	$	695,518	$	—	$	695,518

Other Assets:
Derivatives qualifying as hedges	$	—	$	642	$	—	$	—	$	642
Derivatives not qualifying as hedges	—		1,369		—		—		1,369
Derivative instruments	$	—	$	2,011	$	—	$	—	$	2,011

Losses and LAE:	$	—	$	—	$	2,621,122	$	—	$	2,621,122

Other Liabilities:
Derivatives qualifying as hedges	$	—	$	11,452	$	—	$	—	$	11,452
Derivatives not qualifying as hedges	—		4,106		—		—		4,106
Derivative instruments	$	—	$	15,558	$	—	$	—	$	15,558

Valuation Methodologies of Financial Instruments Measured at Fair Value

Short-term and Fixed Maturity Investments

The fair values for all securities in the short-term and fixed maturity investments and funds held - directly managed portfolios are independently provided by the investment accounting service providers, investment managers and investment custodians, each of which utilize internationally recognized independent pricing services. We record the unadjusted price provided by the investment accounting service providers, investment managers or investment custodians and validate this price through a process that includes, but is not limited to: (i) comparison of prices against alternative pricing sources; (ii) quantitative analysis (e.g. comparing the quarterly return for each managed portfolio to its target benchmark); (iii) evaluation of methodologies used by external parties to estimate fair value, including a review of the inputs used for pricing; and (iv) comparing the price to our knowledge of the current investment market. Our internal price validation procedures and review of fair value methodology documentation provided by independent pricing services have not historically resulted in adjustment in the prices obtained from the pricing service.

The independent pricing services used by the investment accounting service providers, investment managers and investment custodians obtain actual transaction prices for securities that have quoted prices in active markets. Where we utilize single unadjusted broker-dealer quotes, they are generally provided by market makers or broker-dealers who are recognized as market participants in the markets for which they are providing the quotes. For determining the fair value of securities that are not actively traded, in general, pricing services use "matrix pricing" in which the independent pricing service uses observable market inputs including, but not limited to, reported trades, benchmark yields, broker-dealer quotes, interest rates, prepayment speeds, default rates and other such inputs as are available from market sources to determine a reasonable fair value.

The following describes the techniques generally used to determine the fair value of our short-term and fixed maturity investments by asset class, including the investments underlying the funds held - directly managed.

•

U.S. government and agency securities consist of securities issued by the U.S. Treasury and mortgage pass-through agencies such as the Federal National Mortgage Association, the Federal Home Loan Mortgage Corporation and other agencies. Non-U.S. government securities consist of bonds issued by non-U.S. governments and agencies along with supranational organizations. The significant inputs used to determine the fair value of these securities include the spread above the risk-free yield curve, reported trades and broker-dealer quotes. These are considered to be observable market inputs and, therefore, the fair values of these securities are classified as Level 2.

•

Corporate securities consist primarily of investment-grade debt of a wide variety of corporate issuers and industries. The fair values of these securities are determined using the spread above the risk-free yield curve, reported trades, broker-dealer quotes, benchmark yields, and industry and market indicators. These are considered observable market inputs and, therefore, the fair values of these securities are classified as Level 2. Where pricing is unavailable from pricing services, such as in periods of low trading activity or when transactions are not orderly, we obtain non-binding quotes from broker-dealers. Where significant inputs are unable to be corroborated with market observable information, we classify the securities as Level 3.


•	Municipal securities consist primarily of bonds issued by U.S.-domiciled state and municipal entities. The fair values of these securities are determined using the spread above the risk-free yield curve, reported trades, broker-dealer quotes and benchmark yields. These are considered observable market inputs and, therefore, the fair values of these securities are classified as Level 2.

•

Asset-backed securities consist primarily of investment-grade bonds backed by pools of loans with a variety of underlying collateral. Residential and commercial mortgage-backed securities include both agency and non-agency originated securities. Where pricing is unavailable from pricing services, we obtain non-binding quotes from broker-dealers. This is generally the case when there is a low volume of trading activity and current transactions are not orderly. The significant inputs used to determine the fair value of these securities include the spread above the risk-free yield curve, reported trades, benchmark yields, prepayment speeds and default rates. The fair values of these securities are classified as Level 2 if the significant inputs are market observable. Where significant inputs are unable to be corroborated with market observable information, we classify the securities as Level 3.

Equities

Our investments in equities consist of a combination of publicly and privately traded investments. Our publicly traded equity investments in common and preferred stocks predominantly trade on major exchanges and are managed by our external advisors. Our exchange-traded funds also trade on major exchanges. Our publicly traded equities are widely diversified and there is no significant concentration in any specific industry. We use an internationally recognized pricing service to estimate the fair value of our publicly traded equities and exchange-traded funds. We have categorized the majority of our publicly traded equity investments, other than preferred stock, and our exchange-traded funds as Level 1 investments because the fair values of these investments are based on unadjusted quoted prices in active markets for identical assets. One equity security is trading in an inactive market and, as a result has been classified as Level 2. The fair value estimates of our investments in publicly traded preferred stock are based on observable market data and, as a result, have been categorized as Level 2.

Our privately held equity investments in common and preferred stocks are direct investments in companies that we believe offer attractive risk adjusted returns and/or offer other strategic advantages. Each investment may have its own unique terms and conditions and there may be restrictions on disposals. The market for these investments is illiquid and there is no active market. We use a combination of cost, internal models, reported values from co-investors/managers and observable inputs, such as capital raises and capital transactions between new and existing shareholders to calculate the fair value of the privately held equity investments. The fair value estimates of our investments in privately held equities are based on unobservable market data and, as a result, have been categorized as Level 3.

Other investments, at fair value

We have ongoing due diligence processes with respect to the other investments carried at fair value in which we invest and their managers. These processes are designed to assist us in assessing the quality of information provided by, or on behalf of, each fund and in determining whether such information continues to be reliable or whether further review is warranted. Certain funds do not provide full transparency of their underlying holdings; however, we obtain the audited financial statements for funds annually, and regularly review and discuss the fund performance with the fund managers to corroborate the reasonableness of the reported net asset values ("NAV").

The use of NAV as an estimate of the fair value for investments in certain entities that calculate NAV is a permitted practical expedient. Due to the time lag in the NAV reported by certain fund managers we adjust the valuation for capital calls and distributions. Other investments measured at fair value using NAV as a practical expedient have not been classified in the fair value hierarchy. Other investments for which we do not use NAV as a practical expedient have been valued using prices from independent pricing services, investment managers and broker-dealers.

The following describes the techniques generally used to determine the fair value of our other investments.


•	For our investments in hedge funds, we measure fair value by obtaining the most recently available NAV as advised by the external fund manager or third-party administrator. The fair values of these investments are measured using the NAV as a practical expedient and therefore have not been categorized within the fair value hierarchy.

•

Our investments in fixed income funds and equity funds are valued based on a combination of prices from independent pricing services, external fund managers or third-party administrators. For the publicly available prices we have classified the investments as Level 2. For the non-publicly available prices we are using NAV as a practical expedient and therefore these have not been categorized within the fair value hierarchy.


•	For our investments in private equity funds, we measure fair value by obtaining the most recently available NAV from the external fund manager or third-party administrator. The fair values of these investments are measured using the NAV as a practical expedient and therefore have not been categorized within the fair value hierarchy.

•

We measure the fair value of our direct investment in CLO equities based on valuations provided by independent pricing services, our external CLO equity manager, and valuations provided by the broker or lead underwriter of the investment (the "broker"). The fair values measured using prices provided by independent pricing services have been classified as Level 2 and fair values using prices from brokers have been classified as Level 3 due to the use of unobservable inputs in the valuation and the limited number of relevant trades in secondary markets.


•	For our investments in the CLO equity funds, we measure fair value by obtaining the most recently available NAV as advised by the external fund manager or third party administrator. The fair value of these investments is measured using the NAV as a practical expedient and therefore have not been categorized within the fair value hierarchy.


•	For our investments in private credit funds, we measure fair value by obtaining the most recently available NAV from the external fund manager or third-party administrator. The fair values of these investments are measured using the NAV as a practical expedient and therefore have not been categorized within the fair value hierarchy.

•

Included within other is an investment in a real estate debt fund, for which we measure fair value by obtaining the most recently available NAV from the external fund manager or third-party administrator. The fair value of this investment is measured using the NAV as a practical expedient and therefore has not been categorized within the fair value hierarchy.

Cash and Cash Equivalents

Cash equivalents are short-term, highly liquid investments that are readily convertible to known amounts of cash and are so near their maturity that they present insignificant risk of changes in value due to changes in interest rates. Included within cash and cash equivalents are money market funds, fixed interest deposits and highly liquid fixed maturity investments purchased with an original maturity of three months or less.

The majority of our cash and cash equivalents included within the fair value hierarchy are comprised of money market and liquid reserve funds which have been categorized as Level 1. Fixed interest deposits and highly liquid fixed maturity investments with an original maturity of three months or less have been categorized as Level 2. Operating cash balances are not subject to the recurring fair value measurement guidance and are therefore excluded from the fair value hierarchy.

Insurance Contracts - Fair Value Option

The Company uses an internal model to calculate the fair value of the liability for losses and loss adjustment expenses and reinsurance balances recoverable on paid and unpaid losses for certain retroactive reinsurance contracts where we have elected the fair value option in our Non-life Run-off segment. The fair value was calculated as the aggregate of discounted cash flows plus a risk margin. The discounted cash flow approach uses (i) estimated nominal cash flows based upon an appropriate payment pattern developed in accordance with standard actuarial techniques and (ii) a discount rate based upon a high quality rated corporate bond plus a credit spread for non-performance risk. The model uses corporate bond rates across the yield curve depending on the estimated timing of the future cash flows and specific to the currency of the risk. The risk margin was calculated using the present value of the cost of capital. The cost of capital approach uses (i) projected capital requirements, (ii) multiplied by the risk cost of capital representing the return required for non-hedgeable risk based upon the weighted average cost of capital less investment income and (iii) discounted using the weighted average cost of capital.

Derivative Instruments

The fair values of our foreign currency exchange contracts, as described in Note 5 - "Derivatives and Hedging Instruments" are classified as Level 2. The fair values are based upon prices in active markets for identical contracts.

Level 3 Measurements and Changes in Leveling

Transfers into or out of levels are recorded at their fair values as of the end of the reporting period, consistent with the date of determination of fair value.

Investments

The following tables present a reconciliation of the beginning and ending balances for all investments measured at fair value on a recurring basis using Level 3 inputs:



	Three Months Ended March 31, 2020
	Privately-held Equities			Other Investments			Total
	Privately-held Equities			Other Investments			Total
Beginning fair value	$	268,799		$	87,869		$	356,668
Purchases	1,358			37,292			38,650
Sales	—			(539		)	(539		)
Total realized and unrealized losses	(145		)	(40,368		)	(40,513		)
Transfer out of Level 3 into Level 2	—			(83,740		)	(83,740		)
Ending fair value	$	270,012		$	514		$	270,526



	Three Months Ended March 31, 2019
	Fixed maturity investments									Privately-held Equities		Other Investments		Total
	Corporate			Commercial mortgage-backed			Asset-backed			Privately-held Equities		Other Investments		Total
Beginning fair value	$	37,386		$	7,389		$	9,121		$	228,710	$	39,367	$	321,973
Sales	(2,660		)	(608		)	(321		)	—		—		(3,589		)
Total realized and unrealized gains	257			62			737			—		2,380		3,436
Transfer into Level 3 from Level 2	387			—			6,225			—		—		6,612
Transfer out of Level 3 into Level 2	(32,198		)	(6,843		)	(6,462		)	—		—		(45,503		)
Ending fair value	$	3,172		$	—		$	9,300		$	228,710	$	41,747	$	282,929

Net realized and unrealized gains related to Level 3 assets in the tables above are included in net realized and unrealized gains (losses) in our unaudited condensed consolidated statements of earnings.

The securities transferred from Level 2 to Level 3 were transferred due to insufficient market observable inputs for the valuation of the specific assets. The transfers from Level 3 to Level 2 were based upon obtaining market observable information regarding the valuations of the specific assets.

Valuations Techniques and Inputs

The table below presents the quantitative information related to the fair value measurements for investments measured at fair value on a recurring basis using Level 3 inputs:



Qualitative Information about Level 3 Fair Value Measurements
	Fair Value as of March 31, 2020		Valuation Techniques	Unobservable Input	Range (Average) ⁽¹⁾
	(in millions of U.S. dollars)
Privately held equity investments	$	270.0	Transactional value	Implied price at recent purchase transaction	13.50 - 13.85
Privately held equity investments	$	270.0	Cost as approximation of fair value	Cost as approximation of fair value

⁽¹⁾ The average represents the arithmetic average of the inputs and is not weighted by the relative fair value.

Insurance Contracts - Fair Value Option

The following table presents a reconciliation of the beginning and ending balances for all insurance contracts measured at fair value on a recurring basis using Level 3 inputs:



	Three Months Ended March 31,
	2020									2019
	Liability for losses and LAE			Reinsurance balances recoverable			Net			Liability for losses and LAE			Reinsurance balances recoverable			Net
Beginning fair value	$	2,621,122		$	695,518		$	1,925,604		$	2,874,055		$	739,591		$	2,134,464
Assumed business	4,975			—			4,975			—			—			—
Incurred losses and LAE:
Reduction in estimates of ultimate losses	(14,439		)	(3,171		)	(11,268		)	(7,154		)	(3,486		)	(3,668		)
Reduction in unallocated LAE	(6,413		)	—			(6,413		)	(4,341		)	—			(4,341		)
Change in fair value	(64,804		)	(6,567		)	(58,237		)	77,461			21,420			56,041
Total incurred losses and LAE	(85,656		)	(9,738		)	(75,918		)	65,966			17,934			48,032
Paid losses	(81,163		)	(16,114		)	(65,049		)	(115,860		)	(27,242		)	(88,618		)
Effect of exchange rate movements	(113,735		)	(16,270		)	(97,465		)	23,632			4,974			18,658
Ending fair value	$	2,345,543		$	653,396		$	1,692,147		$	2,847,793		$	735,257		$	2,112,536

Changes in fair value in the table above are included in net incurred losses and LAE in our consolidated statements of earnings.

The following table presents the components of the net change in fair value:



	Three Months Ended March 31,
	2020			2019
Changes in fair value due to changes in:
Duration	$	4,148		$	9,047
Corporate bond yield	(64,092		)	46,994
Weighted cost of capital	(5,048		)	—
Risk cost of capital	6,755			—
Change in fair value	$	(58,237	)	$	56,041

Below is a summary of the quantitative information regarding the significant observable and unobservable inputs used in the internal model to determine fair value on a recurring basis:



		March 31, 2020	December 31, 2019
Valuation Technique	Unobservable (U) and Observable (O) Inputs	Weighted Average	Weighted Average
Internal model	Corporate bond yield (O)	A rated	A rated
Internal model	Credit spread for non-performance risk (U)	0.2%	0.2%
Internal model	Risk cost of capital (U)	5.1%	5.1%
Internal model	Weighted average cost of capital (U)	8.25%	8.5%
Internal model	Duration - liability (U)	7.91 years	7.82 years
Internal model	Duration - reinsurance balances recoverable (U)	8.74 years	8.68 years

The fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses may increase or decrease due to changes in the corporate bond rate, the credit spread for non-performance risk, the risk cost of capital, the weighted average cost of capital and the estimated payment pattern as described below:


•	An increase in the corporate bond rate or credit spread for non-performance risk would result in a decrease

in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses. Conversely, a decrease in the corporate bond rate or credit spread for non-performance risk would result in an increase in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses.

•

An increase in the weighted average cost of capital would result in an increase in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses. Conversely, a decrease in the weighted average cost of capital would result in a decrease in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses.


•	An increase in the risk cost of capital would result in an increase in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses. Conversely, a decrease in the risk cost of capital would result in a decrease in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses.

•

The duration of the liability and recoverable is adjusted every period to reflect actual net payments during the period and expected future payments. An acceleration of the estimated payment pattern, a decrease in duration, would result in an increase in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses. Conversely, a deceleration of the estimated payment pattern, an increase in duration, would result in a decrease in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses.

In addition, the estimate of the capital required to support the liabilities is based upon current industry standards for capital adequacy. If the required capital per unit of risk increases, then the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses would increase. Conversely, a decrease in required capital would result in a decrease in the fair value of the liability for losses and LAE and reinsurance balances recoverable on paid and unpaid losses.

Disclosure of Fair Values for Financial Instruments Carried at Cost

Senior Notes

As of March 31, 2020, our 4.50% Senior Notes due 2022 (the "2022 Senior Notes") and our 4.95% Senior Notes due 2029 (the "2029 Senior Notes" and, together with the 2022 Senior Notes, the "Senior Notes") were carried at amortized cost of $348.8 million and $493.6 million, respectively, while the fair value based on observable market pricing from a third party pricing service was $347.0 million and $475.0 million, respectively. The Senior Notes are classified as Level 2.

Insurance Contracts

Disclosure of fair value of amounts relating to insurance contracts is not required, except those for which we elected the fair value option, as described above.

Remaining Assets and Liabilities

Our remaining assets and liabilities were generally carried at cost or amortized cost, which due to their short-term nature approximates fair value as of March 31, 2020 and December 31, 2019.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Premiums Written and Earned

3 Months Ended

Mar. 31, 2020

Insurance [Abstract]

PREMIUMS WRITTEN AND EARNED

6. REINSURANCE BALANCES RECOVERABLE ON PAID AND UNPAID LOSSES

The following tables provide the total reinsurance balances recoverable on paid and unpaid losses:



	March 31, 2020
	Non-life Run-off			Atrium		StarStone			Total
Recoverable from reinsurers on unpaid:
Outstanding losses	$	957,961		$	8,140	$	321,921		$	1,288,022
IBNR	602,508			24,781		263,222			890,511
Fair value adjustments - acquired companies	(13,353		)	514		(1,678		)	(14,517		)
Fair value adjustments - fair value option	(93,935		)	—		—			(93,935		)
ULAE	7,827			—		—			7,827
Total reinsurance reserves recoverable	1,461,008			33,435		583,465			2,077,908
Paid losses recoverable	137,210			1,181		103,478			241,869
Total	$	1,598,218		$	34,616	$	686,943		$	2,319,777

Reconciliation to Consolidated Balance Sheet:
Reinsurance balances recoverable on paid and unpaid losses	$	944,822		$	34,616	$	686,943		$	1,666,381
Reinsurance balances recoverable on paid and unpaid losses - fair value option	653,396			—		—			653,396
Total	$	1,598,218		$	34,616	$	686,943		$	2,319,777



	December 31, 2019
	Non-life Run-off			Atrium		StarStone			Total
Recoverable from reinsurers on unpaid:
Outstanding losses	$	972,293		$	9,011	$	328,009		$	1,309,313
IBNR	673,059			19,286		211,404			903,749
Fair value adjustments - acquired companies	(13,652		)	519		(2,122		)	(15,255		)
Fair value adjustments - fair value option	(88,086		)	—		—			(88,086		)
Total reinsurance reserves recoverable	1,543,614			28,816		537,291			2,109,721
Paid losses recoverable	181,375			1,541		87,253			270,169
Total	$	1,724,989		$	30,357	$	624,544		$	2,379,890

Reconciliation to Consolidated Balance Sheet:
Reinsurance balances recoverable on paid and unpaid losses	$	1,029,471		$	30,357	$	624,544		$	1,684,372
Reinsurance balances recoverable on paid and unpaid losses - fair value option	695,518			—		—			695,518
Total	$	1,724,989		$	30,357	$	624,544		$	2,379,890

Top Ten Reinsurers



	March 31, 2020
	Non-life Run-off		Atrium		StarStone		Total		% of Total
Top 10 reinsurers	$	1,075,150	$	25,328	$	430,788	$	1,531,266	66.0	%
Other reinsurers > $1 million	510,504		8,742		253,127		772,373		33.3	%
Other reinsurers < $1 million	12,564		546		3,028		16,138		0.7	%
Total	$	1,598,218	$	34,616	$	686,943	$	2,319,777	100.0	%



	December 31, 2019
	Non-life Run-off		Atrium		StarStone		Total		% of Total
Top 10 reinsurers	$	1,154,110	$	22,051	$	388,171	$	1,564,332	65.7	%
Other reinsurers > $1 million	551,636		7,761		233,871		793,268		33.4	%
Other reinsurers < $1 million	19,243		545		2,502		22,290		0.9	%
Total	$	1,724,989	$	30,357	$	624,544	$	2,379,890	100.0	%



	March 31, 2020		December 31, 2019
Information regarding top ten reinsurers:
Number of top 10 reinsurers rated A- or better	8		8
Number of top 10 non-rated reinsurers ⁽¹⁾	2		2

Reinsurers rated A- or better in top 10	$	1,260,977	$	1,292,207
Collaterized non-rated reinsurers in top 10 ⁽¹⁾	270,289		272,125
Total top 10 reinsurance recoverables	$	1,531,266	$	1,564,332

Single reinsurers that represent 10% or more of total reinsurance balance recoverables as of March 31, 2020:

Hannover Ruck SE ⁽²⁾	$	264,424	$	261,295
Lloyd's Syndicates ⁽³⁾	$	412,790	$	411,030

⁽²⁾ Hannover Ruck SE is rated AA- by Standard & Poor’s and A+ by A.M. Best.

⁽³⁾ Lloyd's Syndicates are rated A+ by Standard & Poor's and A by A.M. Best.

Allowance for Estimated Uncollectible Reinsurance Balances Recoverable on Paid and Unpaid Losses



	March 31, 2020
	Gross		Allowance for estimated uncollectible reinsurance		Net		Provisions as a % of Gross
Reinsurers rated A- or above	$	1,853,658	$	42,759	$	1,810,899	2.3	%
Reinsurers rated below A-, secured	478,752		—		478,752		—	%
Reinsurers rated below A-, unsecured	130,694		100,568		30,126		76.9	%
Total	$	2,463,104	$	143,327	$	2,319,777	5.8	%



	December 31, 2019
	Gross		Allowance for estimated uncollectible reinsurance		Net		Provisions as a % of Gross
Reinsurers rated A- or above	$	1,904,268	$	43,427	$	1,860,841	2.3	%
Reinsurers rated below A-, secured	487,608		—		487,608		—	%
Reinsurers rated below A-, unsecured	135,653		104,212		31,441		76.8	%
Total	$	2,527,529	$	147,639	$	2,379,890	5.8	%

The table below provides a reconciliation of the beginning and ending allowance for estimated uncollectible reinsurance balances for the three months ended March 31, 2020:



	Three Months Ended
	March 31, 2020
Allowance for estimated uncollectible reinsurance, beginning of period	$	147,639
Cumulative effect of change in accounting principle	(195		)
Current period change in the allowance	(4,117		)
Allowance for estimated uncollectible reinsurance, end of period	$	143,327

During the three months ended March 31, 2020, we did not have any write-offs charged against the allowance for estimated uncollectible reinsurance or any recoveries of amounts previously written off.

11. PREMIUMS WRITTEN AND EARNED

The following table provides a summary of premiums written and earned by segment and for our other activities:



	Three Months Ended March 31,
	2020						2019
	Premiums Written			Premiums Earned			Premiums Written			Premiums Earned
Non-life Run-off
Gross	$	327		$	18,078		$	(20,877	)	$	83,966
Ceded	1,849			(2,048		)	1,699			(7,292		)
Net	$	2,176		$	16,030		$	(19,178	)	$	76,674
Atrium
Gross	$	57,837		$	47,833		$	53,985		$	43,386
Ceded	(9,139		)	(5,463		)	(7,486		)	(4,633		)
Net	$	48,698		$	42,370		$	46,499		$	38,753
StarStone
Gross	$	279,854		$	258,107		$	251,373		$	268,264
Ceded	(90,819		)	(59,947		)	(56,772		)	(55,002		)
Net	$	189,035		$	198,160		$	194,601		$	213,262
Other
Gross	$	(3,885	)	$	2,673		$	864		$	6,673
Ceded	664			664			(19		)	(75		)
Net	$	(3,221	)	$	3,337		$	845		$	6,598
Total
Gross	$	334,133		$	326,691		$	285,345		$	402,289
Ceded	(97,445		)	(66,794		)	(62,578		)	(67,002		)
Total	$	236,688		$	259,897		$	222,767		$	335,287

Goodwill and Intangible Assets

3 Months Ended

Mar. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

GOODWILL AND INTANGIBLE ASSETS

12. GOODWILL AND INTANGIBLE ASSETS

The following table presents a reconciliation of the beginning and ending goodwill and intangible assets during the three months ended March 31, 2020:



			Intangible assets
	Goodwill		Intangible assets with a definite life			Intangible assets with an indefinite life		Total			Total
Balance as of January 1, 2020	$	114,807	$	14,630		$	87,031	$	101,661		$	216,468
Amortization	—		(508		)	—		(508		)	(508		)
Balance as of March 31, 2020	$	114,807	$	14,122		$	87,031	$	101,153		$	215,960

Refer to Note 14 - "Goodwill and Intangible Assets" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019 for more information on goodwill and intangible assets.

The following table provides a summary of the amortization recorded on the intangible assets:



	Three Months Ended March 31,
	2020		2019
Intangible asset amortization	$	508	$	565

The gross carrying value, accumulated amortization and net carrying value of intangible assets by type was as follows:



	March 31, 2020							December 31, 2019
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Gross Carrying Value		Accumulated Amortization			Net Carrying Value
Intangible assets with a definite life:
Distribution channel	$	20,000	$	(8,444	)	$	11,556	$	20,000	$	(8,111	)	$	11,889
Brand	7,000		(4,434		)	2,566		7,000		(4,259		)	2,741
Total	$	27,000	$	(12,878	)	$	14,122	$	27,000	$	(12,370	)	$	14,630
Intangible assets with an indefinite life:
Lloyd’s syndicate capacity	$	37,031	$	—		$	37,031	$	37,031	$	—		$	37,031
Licenses	19,900		—			19,900		19,900		—			19,900
Management contract	30,100		—			30,100		30,100		—			30,100
Total	$	87,031	$	—		$	87,031	$	87,031	$	—		$	87,031

Debt Obligations and Credit Facilities

3 Months Ended

Mar. 31, 2020

Debt Disclosure [Abstract]

DEBT OBLIGATIONS AND CREDIT FACILITIES

13. DEBT OBLIGATIONS AND CREDIT FACILITIES

We primarily utilize debt facilities for funding acquisitions and for significant new business, investment activities and, from time to time, for general corporate purposes. Our debt obligations were as follows:



Facility	Origination Date	Term	March 31, 2020		December 31, 2019
4.50% Senior Notes due 2022	March 10, 2017	5 years	$	348,794	$	348,616
4.95% Senior Notes due 2029	May 28, 2019	10 years	493,643		493,600
Total Senior Notes			842,437		842,216
EGL Revolving Credit Facility	August 16, 2018	5 years	350,000		—
2018 EGL Term Loan Facility	December 27, 2018	3 years	349,117		348,991
Total debt obligations			$	1,541,554	$	1,191,207

During the three months ended March 31, 2020, we utilized $364.0 million and repaid $14.0 million under our facilities. The facilities were utilized for funding significant new business as described in Note 3 - "Significant New Business" and providing additional liquidity to the Company to maximize financial flexibility following the recent disruption in global financial markets associated with the COVID-19 pandemic.

The table below provides a summary of the total interest expense:



	Three Months Ended March 31,
	2020		2019
Interest expense on debt obligations	$	13,195	$	10,453
Amortization of debt issuance costs	220		273
Funds withheld balances and other	—		310
Total interest expense	$	13,415	$	11,036

Senior Notes

4.50% Senior Notes due 2022

On March 10, 2017, we issued the 2022 Senior Notes for an aggregate principal amount of $350.0 million. The 2022 Senior Notes pay 4.5% interest semi-annually and mature on March 10, 2022. The 2022 Senior Notes are unsecured and unsubordinated obligations that rank equal to any of our other unsecured and unsubordinated obligations, senior to any future obligations that are expressly subordinated to the 2022 Senior Notes, effectively subordinate to any of our secured indebtedness to the extent of the value of the assets securing such indebtedness, and structurally subordinate to all liabilities of our subsidiaries.

The 2022 Senior Notes are rated BBB- and are redeemable at our option on a make whole basis at any time prior to the date that is one month prior to the maturity of the 2022 Senior Notes. On or after the date that is one month prior to the maturity of the 2022 Senior Notes, the notes are redeemable at a redemption price equal to 100% of the principal amount of the 2022 Senior Notes to be redeemed.

We incurred costs of $2.9 million in issuing the 2022 Senior Notes. These costs included underwriters’ fees, legal and accounting fees, and other fees, and are capitalized and presented as a direct deduction from the principal amount of debt obligations in the consolidated balance sheets. These costs are amortized over the term of the 2022 Senior Notes and are included in interest expense in our consolidated statements of earnings. The unamortized costs as of March 31, 2020 and December 31, 2019 were $1.2 million and $1.4 million, respectively.

4.95% Senior Notes due 2029

On May 28, 2019, we issued the 2029 Senior Notes for an aggregate principal amount of $500.0 million. The 2029 Senior Notes pay 4.95% interest semi-annually and mature on June 1, 2029. The 2029 Senior Notes are unsecured and unsubordinated obligations that rank equal to any of our other unsecured and unsubordinated obligations, senior to any future obligations that are expressly subordinated to the 2029 Senior Notes, effectively subordinate to any of

our secured indebtedness to the extent of the value of the assets securing such indebtedness, and contractually subordinate to all liabilities of our subsidiaries.

The 2029 Senior Notes are rated BBB- and are redeemable at our option on a make whole basis at any time prior to the date that is three months prior to the maturity of the 2029 Senior Notes. On or after the date that is three months prior to the maturity of the 2029 Senior Notes, the notes are redeemable at a redemption price equal to 100% of the principal amount of the notes to be redeemed.

We incurred costs of $6.8 million in issuing the 2029 Senior Notes. These costs included underwriters’ fees, legal and accounting fees, and other fees, and are capitalized and presented as a direct deduction from the principal amount of debt obligations in the consolidated balance sheets. These costs are amortized over the term of the 2029 Senior Notes and are included in interest expense in our consolidated statements of earnings. The unamortized costs as of March 31, 2020 and December 31, 2019 were $6.4 million.

EGL Revolving Credit Facility

On August 16, 2018, we and certain of our subsidiaries, as borrowers and guarantors, entered into a new five-year unsecured $600.0 million revolving credit agreement. The revolving credit agreement expires in August 2023 and we have the option to increase the commitments under the facility by up to an aggregate amount of $400.0 million from the existing lenders, or through the addition of new lenders subject to the terms of the agreement. Borrowings under the facility will bear interest at a rate based on the Company's long term senior unsecured debt ratings.

As of March 31, 2020, we were permitted to borrow up to an aggregate of $600.0 million under the facility. As of March 31, 2020, there was $250.0 million of available unutilized capacity under the facility. Subsequent to March 31, 2020, we have neither borrowed nor repaid any additional amounts under the facility, as such the unutilized capacity remains at $250.0 million.

Interest is payable at least every month at either the alternate base rate ("ABR") or LIBOR plus a margin as set forth in the revolving credit agreement. The margin could vary based upon any change in our long term senior unsecured debt rating assigned by Standard & Poor's ("S&P") or Fitch. We also pay a commitment fee based on the average daily unutilized portion of the facility. If an event of default occurs, the interest rate may increase and the agent may, and at the request of the required lenders shall, cancel lender commitments and demand early repayment.

2018 EGL Term Loan Facility

On December 27, 2018, we entered into and fully utilized a three-year $500.0 million unsecured term loan (the "2018 EGL Term Loan Facility"). The proceeds were partially used to fund the acquisition of Maiden Re North America, Inc. ("Maiden Re North America"). We have the option to increase the principal amount of the term loan credit facility up to an aggregate amount of $150.0 million from the existing lenders or through the addition of new lenders, subject to the terms of the term loan credit agreement. During 2019, we repaid $150.0 million of principal on the facility, bringing the outstanding loan amount to $349.1 million, which includes unamortized issuance costs of $0.9 million, as of March 31, 2020.

Interest is payable at least every three months at either ABR or LIBOR plus a margin set forth in the term loan credit agreement. The margin could vary based upon any change in our long term senior unsecured debt rating assigned by S&P or Fitch. During the existence of an event of default, the interest rate may increase and the agent may, and at the request of the required lenders shall, demand early repayment.

We incurred costs of $1.5 million associated with closing the 2018 EGL Term Loan Facility. These costs included bank, legal and accounting fees, and other fees, and are capitalized and presented as a direct deduction from the principal amount of debt obligations in the consolidated balance sheets. These costs are amortized over the term of the facility and are included in general and administrative expenses in our consolidated statements of earnings. The unamortized costs as of March 31, 2020 and December 31, 2019 were $0.9 million and $1.0 million, respectively.

Refer to Note 15 - "Debt Obligations and Credit Facilities" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019 for further information on the terms of the above facilities.

Unsecured Letters of Credit

We utilize unsecured letters of credit to support certain of our insurance and reinsurance performance obligations.

Funds at Lloyd's

We have an unsecured letter of credit agreement for Funds at Lloyd's ("FAL Facility") to issue up to $375.0 million of letters of credit, with provision to increase the facility by an additional $25.0 million up to an aggregate amount of $400.0 million, subject to lenders approval. On November 6, 2019, we amended and restated the FAL Facility to extend its term by one year. The FAL Facility is available to satisfy our Funds at Lloyd's requirements and expires in 2023. As of March 31, 2020 and December 31, 2019, our combined Funds at Lloyd's were comprised of cash and investments of $718.0 million and $639.3 million, respectively, and unsecured letters of credit of $252.0 million as of both dates.

$120.0 million Letter of Credit Facility

We use this facility to support certain reinsurance collateral obligations of our subsidiaries. On December 6, 2019, we reduced the facility size from $170.0 million to $120.0 million. Pursuant to the facility agreement, we have the option to increase commitments under the facility by an additional $60.0 million. As of both March 31, 2020 and December 31, 2019, we had issued an aggregate amount of letters of credit under this facility of $115.3 million.

$760.0 million Syndicated Letter of Credit Facility

During 2019, we entered into an unsecured $760.0 million letter of credit facility agreement, most recently amended on December 9, 2019. We may increase the commitments by an aggregate amount of $40.0 million. The facility is used to post letters of credit to collateralize reinsurance performance obligations to various parties, including $447.4 million relating to the reinsurance transaction with Maiden Reinsurance Ltd. ("Maiden Re Bermuda"). As of March 31, 2020 and December 31, 2019, we had issued an aggregate amount of letters of credit under this facility of $610.4 million and $608.0 million, respectively.

Noncontrolling Interests

3 Months Ended

Mar. 31, 2020

Noncontrolling Interest [Abstract]

NONCONTROLLING INTERESTS

14. NONCONTROLLING INTERESTS

We have both redeemable noncontrolling interest ("RNCI") and noncontrolling interest ("NCI") on our consolidated balance sheets. RNCI with redemption features that are not solely within our control are classified within temporary equity in the consolidated balance sheets and carried at redemption value, which is fair value. The change in fair value is recognized through retained earnings as if the balance sheet date were also the redemption date. In addition, we also have NCI, which does not have redemption features and is classified within equity in the consolidated balance sheets.

Redeemable Noncontrolling Interest

RNCI as of March 31, 2020 and 2019 comprised the ownership interests held by the Trident V Funds ("Trident") (39.3%) and Dowling Capital Partners, L.P. ("Dowling") (1.7%) in our subsidiary North Bay Holdings Limited ("North Bay"). North Bay owns our investments in Atrium and StarStone.

The following is a reconciliation of the beginning and ending carrying amount of the equity attributable to the RNCI:



	Three Months Ended
	March 31,
	2020			2019
Balance at beginning of period	$	438,791		$	458,543
Net losses attributable to RNCI	(31,959		)	(2,544		)
Accumulated other comprehensive earnings (losses) attributable to RNCI	(4,170		)	85
Change in redemption value of RNCI	(10,150		)	262
Cumulative effect of change in accounting principle attributable to RNCI ⁽¹⁾	261			—
Balance at end of period	$	392,773		$	456,346

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

We carried the RNCI at its estimated redemption value, which is fair value, as of March 31, 2020 and December 31, 2019. The decrease was primarily attributable to net losses related to StarStone during the three months ended March 31, 2020.

Refer to Note 19 - "Related Party Transactions" and Note 20 - "Commitments and Contingencies" for additional information regarding RNCI.

Noncontrolling Interest

As of March 31, 2020 and December 31, 2019, we had $13.4 million and $14.2 million, respectively, of NCI related to external interests in two of our non-life run-off subsidiaries. A reconciliation of the beginning and ending carrying amount of the equity attributable to NCI is included in the unaudited condensed consolidated statement of changes in shareholders equity.

Share Capital

3 Months Ended

Mar. 31, 2020

Equity [Abstract]

SHARE CAPITAL

15. SHARE CAPITAL

Refer to Note 17 - "Share Capital" to our consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019 for additional information on our share capital.

Dividends Declared and Paid

The following table details the dividends that have been declared and paid on our Series D and E Preferred Shares for the period from January 1, 2020 to May 7, 2020:



				Dividend per:
Preferred Share Series	Date Declared	Record Date	Date Paid or Payable	Preferred Share		Depositary Share		Total dividends paid in the three months ended March 31, 2020
				(in U.S. dollars)				(in thousands of U.S. dollars)
Series D	February 4, 2020	February 15, 2020	March 2, 2020	$	437.50	$	0.43750	$	7,000
Series E	February 4, 2020	February 15, 2020	March 2, 2020	$	437.50	$	0.43750	1,925
Series D	May 5, 2020	May 15, 2020	June 1, 2020	$	437.50	$	0.43750	—
Series E	May 5, 2020	May 15, 2020	June 1, 2020	$	437.50	$	0.43750	—
								$	8,925

Share Repurchases

On March 9, 2020, the Company's Board of Directors adopted a stock trading plan for the purpose of repurchasing a limited number of the Company’s ordinary shares, not to exceed $150.0 million in aggregate (the "Repurchase Program"). On March 23, 2020, the Company suspended its Repurchase Program due to uncertainty in the global financial markets resulting from the COVID-19 pandemic. From inception to March 23, 2020, the Company repurchased 92,510 ordinary shares for an aggregate price of $12.5 million under the Repurchase Program. The average price paid per share repurchased was $135.40.

Joint Share Ownership Plan

On January 21, 2020, 565,630 Voting Ordinary Shares were issued to the trustee of the Enstar Group Limited Employee Benefit Trust (the "EB Trust"). Voting rights in respect of shares held in the EB Trust have been contractually waived. We have consolidated the EB Trust, and shares held in the EB Trust are classified like treasury shares as contra-equity in our consolidated balance sheet.

The EB Trust supports awards made under our Joint Share Ownership Plan, a sub-plan to our Amended and Restated 2016 Equity Incentive Plan (the "JSOP"). An award of 565,630 shares was made to our Chief Executive Officer on January 21, 2020, which cliff-vests after 3 years from grant. The accounting for stock-settled JSOP awards is similar to options, whereby the grant date fair value of $13.6 million is expensed over the life of the award. To determine the grant date fair value of $24.13 per share, we utilized a Monte-Carlo valuation model with the following assumptions: (i) volatility of 18.66%; (ii) dividend yield of 0.00%; and (iii) risk-free interest rate of 1.55%. For further information on the EB Trust and JSOP award, including the vesting conditions, refer to Note 17 - "Share Capital" and Note 19 - "Share-Based Compensation and Pensions" to our consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019.

Earnings Per Share

3 Months Ended

Mar. 31, 2020

Earnings Per Share [Abstract]

EARNINGS PER SHARE

16. EARNINGS PER SHARE

The following table sets forth the computation of basic and diluted net earnings per ordinary share:



	Three Months Ended
	March 31,
	2020			2019
Numerator:
Net earnings (losses) attributable to Enstar ordinary shareholders:	$	(516,821	)	$	358,751
Denominator:
Weighted-average ordinary shares outstanding — basic ⁽¹⁾	21,549,844			21,463,499
Effect of dilutive securities:
Share-based compensation plans ⁽²⁾	164,435			122,980
Warrants	65,627			59,383
Weighted-average ordinary shares outstanding — diluted	21,779,906			21,645,862

Earnings (losses) per ordinary share attributable to Enstar:
Basic net earnings (losses) per ordinary share	$	(23.98	)	$	16.71
Diluted net earnings (losses) per ordinary share ⁽³⁾	$	(23.98	)	$	16.57

⁽¹⁾Weighted-average ordinary shares for basic earnings per share includes ordinary shares (voting and non-voting) but excludes ordinary shares held in the EB Trust in respect of JSOP awards.

⁽²⁾ Share-based dilutive securities include restricted shares, restricted share units, and performance share units. Certain share-based compensation awards, including the ordinary shares held in the EB Trust in respect of JSOP awards, were excluded from the calculation for the three months ended March 31, 2020 because they were anti-dilutive.

⁽³⁾During a period of loss, the basic weighted average ordinary shares outstanding is used in the denominator of the diluted loss per ordinary share computation as the effect of including potentially dilutive securities would be anti-dilutive.

Share-Based Compensation and Pensions

3 Months Ended

Mar. 31, 2020

Retirement Benefits [Abstract]

SHARE-BASED COMPENSATION AND PENSIONS

17. SHARE-BASED COMPENSATION

We provide various employee benefits including share-based compensation, an employee share purchase plan and an annual incentive compensation program. These are described in Note 19 - "Share-Based Compensation and Pensions" to our consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019.

The table below provides a summary of the compensation costs for all of our share-based compensation plans:



	Three Months Ended March 31,
	2020			2019
Share-based compensation plans:
Restricted shares and restricted share units	$	1,599		$	1,843
Performance share units	(667		)	1,325
Cash-settled stock appreciation rights	(3,159		)	56
Joint share ownership plan expense	872			—
Other share-based compensation plans:
Northshore incentive plan	472			1,046
StarStone incentive plan	(223		)	—
Deferred compensation and ordinary share plan for non-employee directors	866			827
Employee share purchase plan	104			103
Total share-based compensation	$	(136	)	$	5,200

Income Taxation	3 Months Ended
Income Taxation	Mar. 31, 2020
Income Tax Disclosure [Abstract]
INCOME TAXATION	18. INCOME TAXATION Interim Tax Calculation Method We use the estimated annual effective tax rate method for computing our interim tax provision. This method applies our best estimate of the effective tax rate expected for the full year to our year-to-date earnings before income taxes. We provide for income tax expense or benefit based upon our pre-tax earnings and the provisions of currently enacted tax laws. Certain items deemed to be unusual, infrequent or not reliably estimated are excluded from the estimated annual effective tax rate. In the event such items are identified, the actual tax expense or benefit is reported in the same period as the related item. Certain other items are not included in the estimated annual effective tax rate, such as changes in the assessment of valuation allowance on deferred tax assets and uncertain tax positions, if any. Interim Tax Expense The effective tax rates on income for the three months ended March 31, 2020 and 2019 were 0.9% and 1.3%, respectively. The effective tax rate on income differs from the statutory rate of 0% due to tax on foreign operations, primarily the U.S. and the U.K. We have foreign operating subsidiaries and branch operations principally located in the U.S., U.K., Continental Europe and Australia that are subject to federal, foreign, state and local taxes in those jurisdictions. Deferred tax liabilities have not been accrued with respect to the undistributed earnings of our foreign subsidiaries. If the earnings were to be distributed, as dividends or other distributions, withholding taxes may be imposed by the jurisdiction of the paying subsidiary. For our U.S. subsidiaries, we have not currently accrued any withholding taxes with respect to unremitted earnings as management has indefinitely reinvested these earnings. For our U.K. subsidiaries, there are no withholding taxes imposed. For our other foreign subsidiaries, it would not be practicable to compute such amounts due to a variety of factors, including the amount, timing, and manner of any repatriation. Because we operate in many jurisdictions, our net earnings are subject to risk due to changing tax laws and tax rates around the world. The current, rapidly changing economic environment may increase the likelihood of substantial changes to tax laws in the jurisdictions in which we operate. Assessment of Valuation Allowance on Deferred Tax Assets We have estimated the future taxable income of our foreign subsidiaries and have provided a valuation allowance in respect of loss carryforwards where we do not expect to realize a benefit. We have considered all available evidence using a "more likely than not" standard in determining the amount of the valuation allowance. During the three months ended March 31, 2020, we have determined that there is sufficient positive evidence to conclude that it is more likely than not that additional deferred taxes of $1.8 million are realizable and have maintained a valuation allowance for deferred tax assets which management does not believe meet the “more likely than not” criteria. Unrecognized Tax Benefits There were no unrecognized tax benefits as of March 31, 2020 and December 31, 2019. Tax Examinations Our operating subsidiaries may be subject to audit by various tax authorities and may have different statutes of limitations expiration dates. With limited exceptions, our major subsidiaries that operate in the U.S., U.K. and Australia are no longer subject to tax examinations for years before 2015.

Related Party Transactions

3 Months Ended

Mar. 31, 2020

RELATED PARTY TRANSACTIONS

19. RELATED PARTY TRANSACTIONSStone Point Capital LLC

Through several private transactions occurring from May 2012 to July 2012 and an additional private transaction that closed in May 2018, investment funds managed by Stone Point Capital LLC ("Stone Point") have acquired an aggregate of 1,635,986 of our Voting Ordinary Shares (which constitutes approximately 8.8% of our outstanding Voting Ordinary Shares). On November 6, 2013, we appointed James D. Carey to our Board of Directors. Mr. Carey is the sole member of an entity that is one of four general partners of the entities serving as general partners for Trident, is a member of the investment committees of such general partners, and is a member and senior principal of Stone Point, the manager of the Trident funds.

In addition, we have entered into certain agreements with Trident with respect to Trident’s co-investments in the Atrium, Arden, and StarStone acquisitions. These include investors’ agreements and shareholders’ agreements, which provide for, among other things: (i) our right to redeem Trident’s equity interest in the Atrium/Arden and StarStone transactions in cash at fair market value at any time following September 6, 2020 and April 1, 2021, respectively; and (ii) Trident’s right to have its equity co-investment interests in the Atrium/Arden and StarStone transactions redeemed by us at fair market value (which we may satisfy in either cash or our ordinary shares) following September 6, 2020 and April 1, 2021, respectively. We did not exercise our prior right to redeem Trident's equity interest in Atrium/Arden during the 90 days following September 6, 2018, nor did we exercise our prior right to redeem Trident's equity interest in StarStone during the 90 days following April 1, 2019. Pursuant to the terms of the shareholders’ agreements, Mr. Carey serves as a Trident representative on the boards of the holding companies, including North Bay Holdings Limited ("North Bay"), established in connection with the Atrium/Arden and StarStone co-investment transactions. Trident also has a second representative on these boards who is a Stone Point employee.

We, in partnership with StarStone's other shareholders, have recently completed two transactions to provide capital support to StarStone in the form of:

(i) a contribution to its contributed surplus account and a loss portfolio transfer, effective October 1, 2018. To fund the transaction, the North Bay shareholders contributed an aggregate amount of $135.0 million to North Bay in proportion to their ownership interests. Trident’s proportionate contribution of $53.1 million was temporarily funded by North Bay and was reimbursed in the first quarter of 2019; and

(ii) a loss portfolio transfer, effective April 1, 2019, for which shareholders agreed to contribute an aggregate amount of $48.0 million.

In addition, Enstar has separately entered into a loss portfolio transfer and adverse development cover with StarStone effective October 1, 2019, whereby StarStone transferred $189.4 million in loss reserves and unearned premium to a wholly-owned Enstar subsidiary in exchange for premium of $189.4 million. Enstar also provided an additional $59.0 million adverse development cover in excess of the $189.4 million.

The RNCI on our balance sheet relating to these Trident co-investment transactions was as follows:



	March 31, 2020		December 31, 2019
Redeemable Noncontrolling Interest	$	376,399	$	420,499

As of March 31, 2020, we had the following additional relationships with Stone Point and its affiliates:


•	Investments in funds (carried within other investments) managed by Stone Point, with respect to which we recognized net unrealized gains (losses);


•	Investments in registered investment companies affiliated with entities owned by Trident or otherwise affiliated with Stone Point, with respect to which we recognized net unrealized gains (losses) and interest income;


•	Separate accounts managed by Eagle Point Credit Management, PRIMA Capital Advisors and SKY Harbor Capital Management, which are affiliates of entities owned by Trident, with respect to which we incurred management fees;


•	Investments in funds (carried within other investments) managed by Sound Point Capital, an entity in which Mr. Carey has an indirect minority ownership interest and serves as a director, with respect to which we recognized net unrealized gains (losses);


•	Sound Point Capital has acted as collateral manager for certain of our direct investments in CLO debt and equity securities, with respect to which we recognized net unrealized gains (losses) and interest income;


•	Marble Point Capital, which is an affiliate of an entity owned by Trident, has acted as collateral manager for certain of our direct investments in CLO debt and equity securities, with respect to which we recognized net unrealized gains (losses) and interest income;


•	A separate account managed by Sound Point Capital, with respect to which we incurred management fees in prior periods; and

•

In the fourth quarter of 2018, we invested $25.0 million in Mitchell TopCo Holdings, the parent company of Mitchell International and Genex Services, as a co-investor alongside certain Trident funds.

The following table presents the amounts included in our consolidated balance sheet related to our related party transactions with Stone Point and its affiliated entities:



	March 31, 2020		December 31, 2019
Short-term investments, AFS, at fair value	$	1,134	$	1,431
Fixed maturities, trading, at fair value	208,255		269,131
Fixed maturities, AFS, at fair value	199,563		160,303
Equities, at fair value	91,820		121,794
Other investments, at fair value:
Hedge funds	16,501		18,993
Fixed income funds	310,397		381,449
Private equity funds	32,241		34,858
CLO equities	31,842		32,560
CLO equity funds	66,938		87,509
Private Debt	16,528		16,312
Real estate fund	21,644		18,106
Cash and cash equivalents	55,391		54,080
Other assets	346		10
Other liabilities	457		4,710

The following table presents the amounts included in net earnings related to our related party transactions with Stone Point and its affiliated entities:



	Three Months Ended March 31,
	2020			2019
Net investment income	$	4,084		$	1,075
Net realized and unrealized (losses) gains	(102,516		)	20,133
Total net (losses) earnings	$	(98,432	)	$	21,208

Hillhouse Capital

Investment funds managed by managed by Hillhouse Capital Management, Ltd. and Hillhouse Capital Advisors, Ltd. (together, “Hillhouse Capital”) collectively own approximately 9.4% of Enstar’s voting ordinary shares. These funds also own non-voting ordinary shares and warrants to purchase additional non-voting ordinary shares, which together with their voting ordinary shares, represent an approximate 16.5% economic interest in Enstar. In February 2017, Jie Liu, a Partner of AnglePoint (defined below), was appointed to our Board.

We have direct investments in funds managed by Hillhouse Capital and AnglePoint Asset Management Ltd. ("AnglePoint"). As of March 31, 2020, our carrying value of our direct investment the InRe Fund, L.P. ("InRe Fund"), which is managed by AnglePoint, was $869.3 million with the fund's assets being invested in approximately 30% in fixed income securities, 15% in North American equities, 80% in international equities and (25)% in financing, derivatives and other items.

As of March 31, 2020 and December 31, 2019 our equity method investee, Enhanzed Reinsurance Ltd. ("Enhanzed Re"), had investments in a fund managed by AnglePoint, as set forth in the table below.

Our consolidated balance sheet included the following balances related to transactions with Hillhouse Capital and AnglePoint:



	March 31, 2020			December 31, 2019
Investments in funds managed by AnglePoint, held by Enhanzed Re	$	380,681		$	327,799
Our ownership of equity method investments	47.4		%	47.4		%
Our share of funds managed by AnglePoint, held by Enhanzed Re	$	180,443		$	155,377

Investment in other funds managed by Hillhouse Capital and AnglePoint:
InRe Fund	$	869,275		$	918,633
Other funds	213,123			232,968
	$	1,082,398		$	1,151,601

The decrease in the investment in funds managed by Hillhouse Capital and AnglePoint was primarily due to unrealized losses for the three months ended March 31, 2020. We incurred fees of approximately $2.3 million, included within the funds' reported NAV, for the three months ended March 31, 2020 in relation to the investment in funds managed by Hillhouse Capital and AnglePoint as described above.

Monument

Monument Insurance Group Limited ("Monument") was established in October 2016 and Enstar has invested a total of $26.6 million in the common and preferred shares of Monument. We have approximately a 26.6% interest in Monument. In connection with our investment in Monument, we entered into a Shareholders Agreement with the other shareholders. We recorded the investment in Monument using the equity method basis of accounting, as we concluded that we are not required to consolidate based on the guidance in Accounting Standards Codification ("ASC") 810 - Consolidation.

On May 31, 2019, we completed the transfer of our remaining life assurance policies written by our wholly-owned subsidiary Alpha Insurance SA to a subsidiary of Monument. In this transaction, we transferred policy benefits for life and annuity contracts with a carrying value of €88.8 million (or approximately $99.1 million) and total assets with a fair value of €91.1 million (or approximately $101.6 million) to a subsidiary of Monument.

Our investment in the common and preferred shares of Monument, carried in equity method investments on our consolidated balance sheet was as follows:



	March 31, 2020		December 31, 2019
Investment in Monument	$	57,737	$	60,598

Clear Spring (formerly SeaBright)

Effective January 1, 2017, we sold SeaBright Insurance Company (“SeaBright Insurance”) and its licenses to Delaware Life Insurance Company ("Delaware Life"), a subsidiary of Guggenheim Partners, LLC. Following the sale, SeaBright Insurance was renamed Clear Spring Property and Casualty Company (“Clear Spring”). Clear Spring was subsequently capitalized with $56.0 million of equity, with Enstar retaining a 20% indirect equity interest in Clear Spring.

We have recorded the investment in Clear Spring using the equity method basis of accounting, pursuant to the

conclusion that we are not required to consolidate following an analysis based on the guidance in ASC 810 - Consolidation.

Our investment in the common shares of Clear Spring, carried in equity method investments on our consolidated balance sheet, was as follows:



	March 31, 2020		December 31, 2019
Investment in Clear Spring	$	10,952	$	10,645

Effective January 1, 2017, StarStone National Insurance Company (“StarStone National”) entered into a ceding quota share treaty with Clear Spring pursuant to which Clear Spring reinsures 33.3% of core workers' compensation business written by StarStone National. This agreement was terminated as of December 31, 2018.

Effective January 1, 2017, we also entered into an assuming quota share treaty with Clear Spring pursuant to which an Enstar subsidiary reinsures 25% of all workers' compensation business written by Clear Spring. This is recorded as other activities.

Our consolidated balance sheet included the following balances between us and Clear Spring:



	March 31, 2020		December 31, 2019
Balances under StarStone ceding quota share:
Reinsurance balances recoverable	$	23,566	$	22,812
Prepaid insurance premiums	12		51
Ceded payable	4,189		3,616
Ceded acquisition costs	—		21

Balances under assuming quota share:
Losses and LAE	5,307		6,135
Unearned reinsurance premiums	3		13
Funds held	8,303		8,611

Our consolidated statement of earnings included the following amounts between us and Clear Spring:



	Three Months Ended
	March 31,
	2020			2019

Transactions under StarStone ceding quota share:
Ceded premium earned	$	(681	)	$	(5,485	)
Ceded incurred losses and LAE	754			3,859
Ceded acquisition costs	72			54

Transactions under assuming quota share:
Premium earned	170			1,371
Net incurred losses and LAE	372			(965		)
Acquisition costs	(13		)	(14		)

Total net earnings (loss)	$	674		$	(1,180	)

AmTrust

In November 2018, pursuant to a Subscription Agreement with Evergreen Parent L.P. ("Evergreen"), K-Z Evergreen, LLC and Trident Pine Acquisition LP ("Trident Pine"), we purchased equity in Evergreen in the aggregate amount of $200.0 million. Evergreen is an entity formed by private equity funds managed by Stone Point and the Karfunkel-Zyskind family that acquired the approximately 45% of the issued and outstanding shares of common stock of AmTrust that the Karfunkel-Zyskind Family and certain of its affiliates and related parties did not already own or control. The equity interest was in the form of three separate classes of equity securities issued at the same price and in the same proportion as the equity interest purchased by Trident Pine. In a second transaction in December 2019, Enstar acquired an additional $25.9 million of Evergreen securities from another investor.

Following the closing of the second transaction, Enstar owns approximately 8.5% of the equity interest in Evergreen and Trident Pine owns approximately 21.8%. Evergreen owns all of the equity interest in AmTrust. In addition, upon the successful closing of the transaction we received a fee of $3.3 million, half of which was payable upon closing and the other on the first anniversary of the closing. The fee has been recorded in full in other income within our consolidated statements of earnings for the year ended December 31, 2018.

Our indirect investment in the shares of AmTrust, carried in equities on our consolidated balance sheet was as follows:



	March 31, 2020		December 31, 2019
Investment in AmTrust	$	241,328	$	240,115

During the three months ended March 31, 2020 and 2019 we recorded net investment income of $2.5 million and $1.8 million, respectively, and net realized and unrealized losses of $0.1 million and $nil, respectively, related to our indirect equity investment in AmTrust.

Citco

In June 2018, we made a $50.0 million indirect investment in the shares of Citco III Limited ("Citco"), a fund administrator with global operations. Pursuant to an investment agreement and in consideration for participation therein, a related party of Hillhouse Capital provided us with investment support. In a private transaction that preceded our co-investment opportunity, certain Citco shareholders, including Trident, agreed to sell all or a portion of their interests in Citco. As of March 31, 2020, Trident owned an approximate 3.4% interest in Citco. Mr. Carey currently serves as an observer to the board of directors of Citco in connection with Trident's investment therein.

Our indirect investment in the shares of Citco, carried in equity method investments on our consolidated balance sheet, was as follows:



	March 31, 2020		December 31, 2019
Investment in Citco	$	51,504	$	51,742

Enhanzed Re

Enhanzed Re is a joint venture between Enstar, Allianz SE ("Allianz") and Hillhouse Capital that was capitalized in December 2018. Enhanzed Re is a Bermuda-based Class 4 and Class E reinsurer and will reinsure life, non-life run-off, and property and casualty insurance business, initially sourced from Allianz and Enstar. Enstar, Allianz and Hillhouse Capital affiliates have made equity investment commitments in aggregate of $470.0 million to Enhanzed Re. Enstar owns 47.4% of the entity, Allianz owns 24.9% and an affiliate of Hillhouse Capital owns 27.7%. As of March 31, 2020, Enstar contributed $154.1 million of its total capital commitment to Enhanzed Re and had an uncalled amount of $68.7 million. We have accounted for our equity interest in Enhanzed Re as an equity method investment as we have significant influence over its operating and financial policies.

Enstar acts as the (re)insurance manager for Enhanzed Re, for which it receives fee income recorded within other income, AnglePoint acts as the primary investment manager, and an affiliate of Allianz provides investment management services. Enhanzed Re writes business from affiliates of its operating sponsors, Allianz SE and Enstar. It also underwrites other business to maximize diversification by risk and geography.

Our investment in the common shares of Enhanzed Re, carried in equity method investments on our consolidated balance sheet was as follows:



	March 31, 2020		December 31, 2019
Investment in Enhanzed Re	$	197,206	$	182,856

We have ceded 10% of the Zurich transaction, as discussed in Note 4 - "Significant New Business" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019, to Enhanzed Re on the same terms and conditions as those received by Enstar.

Our consolidated balance sheet included the following balances between us and Enhanzed Re:



	March 31, 2020		December 31, 2019
Balances under ceding quota share:
Insurance balances payables	$	1,519	$	1,443
Reinsurance balances recoverable	58,022		59,601
Funds held	48,383		50,089

Other assets	400		1,033

Our consolidated statement of earnings included the following amounts between us and Enhanzed Re:



	Three Months Ended March 31, 2020
	2020		2019
Amounts under ceding quota share:
Acquisition costs	23		—

Other income	291		86

Total net earnings	$	314	$	86

Commitments and Contingencies

3 Months Ended

Mar. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

20. COMMITMENTS AND CONTINGENCIES

Concentration of Credit Risk

We believe that there are no significant concentrations of credit risk associated with our cash and cash equivalents, fixed maturity investments, or other investments. Our cash and investments are managed pursuant to guidelines that follow prudent standards of diversification and liquidity, and limit the allowable holdings of a single issue and issuers. We are also subject to custodial credit risk on our investments, which we manage by diversifying our holdings amongst large financial institutions that are highly regulated.

We have exposure to credit risk on certain of our assets pledged to ceding companies under insurance contracts. In addition, we are potentially exposed should any insurance intermediaries be unable to fulfill their contractual obligations with respect to payments of balances owed to and by us.

Credit risk exists in relation to insurance and reinsurance balances recoverable on paid and unpaid losses. We remain liable to the extent that counterparties do not meet their contractual obligations and, therefore, we evaluate and monitor concentration of credit risk among our insurers and reinsurers.

We are also subject to credit risk in relation to funds held by reinsured companies. Under funds held arrangements, the reinsured company has retained funds that would otherwise have been remitted to our reinsurance subsidiaries. The funds may be placed into trust or subject to other security arrangements. However, we generally have the contractual ability to offset any shortfall in the payment of the funds held balances with amounts owed by us. As of March 31, 2020, we had a significant funds held concentration of $941.5 million to one reinsured company which has financial strength credit ratings of A+ from A.M. Best and AA from S&P.

We limit the amount of credit exposure to any one counterparty, and none of our counterparty credit exposures, excluding U.S. government instruments and the counterparty noted above, exceeded 10% of shareholders’ equity as of March 31, 2020. Our credit exposure to the U.S. government was $872.4 million as of March 31, 2020.

Legal Proceedings

We are, from time to time, involved in various legal proceedings in the ordinary course of business, including litigation and arbitration regarding claims. Estimated losses relating to claims arising in the ordinary course of business, including the anticipated outcome of any pending arbitration or litigation, are included in the liability for losses and LAE in our consolidated balance sheets. In addition to claims litigation, we may be subject to other lawsuits and regulatory actions in the normal course of business, which may involve, among other things, allegations of underwriting errors or omissions, employment claims or regulatory activity. We do not believe that the resolution of any currently pending legal proceedings, either individually or taken as a whole, will have a material effect on our business, results of operations or financial condition. We anticipate that, similar to the rest of the insurance and reinsurance industry, we will continue to be subject to litigation and arbitration proceedings in the ordinary course of business, including litigation generally related to the scope of coverage with respect to asbestos and environmental and other claims.

Unfunded Investment Commitments

As of March 31, 2020, we had unfunded commitments of $773.6 million and $110.5 million to private equity funds and equity method investments, respectively.

Guarantees

As of March 31, 2020 and December 31, 2019, parental guarantees and capital instruments supporting subsidiaries' insurance obligations were $1.3 billion and $1.0 billion, respectively. We also guarantee the FAL facility, which is described in Note 13 - "Debt Obligations and Credit Facilities."

Redeemable Noncontrolling Interest

We have the right to purchase the RNCI interests from the RNCI holders at certain times in the future (each such right, a "call right") and the RNCI holders have the right to sell their RNCI interests to us at certain times in the future (each such right, a "put right"). The RNCI rights held by Trident are described in Note 19 - "Related Party Transactions." Dowling has a right to participate if Trident exercises its put right.

Leases

Our leases are all currently classified as operating leases whereby the related lease expense is recognized within general and administrative expenses in our consolidated statements of earnings on a straight-line basis over the term of the lease. We also recognize a right-of-use asset and an offsetting lease liability within other assets and other liabilities, respectively, in our consolidated balance sheets, for each operating lease that we enter into.

Our leases are primarily related to office space and facilities used to conduct business operations and have remaining lease terms of one year to 37 years; some of which include options to extend the lease term for up to five years, and some of which include options to terminate the lease within one year. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants.

Since a majority of our leases do not provide an implicit discount rate, we use our collateralized incremental borrowing rate based on the information available at the commencement date of the lease in determining the present value of lease payments. For more information on our leasing arrangements and the related accounting, refer to Note 23 - "Commitments and Contingencies" to the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019.

The table below provides the lease cost and other information relating to our operating leases:



	Three Months Ended March 31,
	2020			2019
Lease cost
Operating lease cost	$	3,322		$	3,487
Short-term lease cost⁽¹⁾	58			—
Total lease cost	3,380			3,487
Sub-lease income⁽²⁾	(138		)	(131		)
Total net lease cost	$	3,242		$	3,356

Other information
Operating Cash paid for amounts included in the measurement of lease liabilities	$	3,183		$	3,024
Non-cash activity: right-of-use assets relating to leases	72			51,609
Weighted-average remaining lease term	6.2 years			6.6 years
Weighted-average discount rate	6.3		%	6.2		%

⁽¹⁾ Leases with an initial lease term of twelve months or less are not recognized within our consolidated balance sheets.

⁽²⁾ Sub-lease income consists of rental income received from third parties to whom we have sub-leased some of our leased office spaces and is included within other income in our consolidated statements of earnings.

The table below provides a summary of the operating leases recorded on our consolidated balance sheets:



	Balance sheet classification	March 31, 2020		December 31, 2019
Right-of-use assets	Other assets	$	39,300	$	46,747
Current lease liabilities	Other liabilities	10,467		11,403
Non-current lease liabilities	Other liabilities	31,319		34,785

The table below provides a summary of the contractual maturities of our operating lease liabilities:



	March 31, 2020
2020	$	9,938
2021	9,578
2022	7,893
2023	6,873
2024	5,147
2025 and beyond	12,205
Total lease payments ⁽¹⁾	51,634
Less: Imputed interest	(9,848		)
Present value of lease liabilities	$	41,786

⁽¹⁾ Amount excludes short-term leases.

Segment Information

3 Months Ended

Mar. 31, 2020

Segment Reporting [Abstract]

SEGMENT INFORMATION

21. SEGMENT INFORMATION

We have three reportable segments of business that are each managed, operated and separately reported: (i) Non-life Run-off; (ii) Atrium; and (iii) StarStone. Our other activities, which do not qualify as a reportable segment, include our corporate expenses, debt servicing costs, holding company income and expenses, foreign exchange and other miscellaneous items. These segments are described in Note 1 - "Description of Business" to our consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2019.

The following tables set forth selected and unaudited condensed consolidated statement of earnings results by segment and for our other activities:



	Three Months Ended March 31, 2020
	Non-life Run-off			Atrium			StarStone			Other			Total
Gross premiums written	$	327		$	57,837		$	279,854		$	(3,885	)	$	334,133

Net premiums written	$	2,176		$	48,698		$	189,035		$	(3,221	)	$	236,688

Net premiums earned	$	16,030		$	42,370		$	198,160		$	3,337		$	259,897
Net incurred losses and LAE	62,034			(28,416		)	(139,030		)	(2,482		)	(107,894		)
Acquisition costs	(6,907		)	(14,384		)	(45,212		)	(83		)	(66,586		)
Operating expenses	(48,210		)	(2,877		)	(34,552		)	—			(85,639		)
Underwriting income (loss)	22,947			(3,307		)	(20,634		)	772			(222		)
Net investment income (loss)	67,451			1,525			11,352			(2,488		)	77,840
Net realized and unrealized losses	(574,682		)	(5,708		)	(54,086		)	—			(634,476		)
Fees and commission income	4,985			2,543			—			—			7,528
Other income (expense)	22,295			35			85			(1,971		)	20,444
Corporate expenses	(8,120		)	(3,138		)	(574		)	(16,040		)	(27,872		)
Interest income (expense)	(15,899		)	—			(447		)	2,931			(13,415		)
Net foreign exchange gains (losses)	14,653			(2,133		)	(590		)	—			11,930
LOSS BEFORE INCOME TAXES	(466,370		)	(10,183		)	(64,894		)	(16,796		)	(558,243		)
Income tax benefit	2,807			753			1,615			—			5,175
Earnings from equity method investments	12,450			—			—			—			12,450
NET LOSS	(451,113		)	(9,430		)	(63,279		)	(16,796		)	(540,618		)
Net loss attributable to noncontrolling interest	2,087			3,868			26,767			—			32,722
NET LOSS ATTRIBUTABLE TO ENSTAR	(449,026		)	(5,562		)	(36,512		)	(16,796		)	(507,896		)
Dividends on preferred shares	—			—			—			(8,925		)	(8,925		)
NET LOSS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$	(449,026	)	$	(5,562	)	$	(36,512	)	$	(25,721	)	$	(516,821	)

Underwriting ratios:
Loss ratio				67.1		%	70.2		%
Acquisition expense ratio				33.9		%	22.8		%
Operating expense ratio				6.8		%	17.4		%
Combined ratio				107.8		%	110.4		%



	Three Months Ended March 31, 2019
	Non-life Run-off			Atrium			StarStone			Other			Total
Gross premiums written	$	(20,877	)	$	53,985		$	251,373		$	864		$	285,345

Net premiums written	$	(19,178	)	$	46,499		$	194,601		$	845		$	222,767

Net premiums earned	$	76,674		$	38,753		$	213,262		$	6,598		$	335,287
Net incurred losses and LAE	(95,182		)	(17,214		)	(195,052		)	(4,956		)	(312,404		)
Life and Annuity Policy Benefits	—			—			—			(96		)	(96		)
Acquisition costs	(28,155		)	(13,742		)	(51,659		)	(232		)	(93,788		)
Operating expenses	(43,992		)	(3,033		)	(35,994		)	—			(83,019		)
Underwriting income (loss)	(90,655		)	4,764			(69,443		)	1,314			(154,020		)
Net investment income (loss)	66,728			1,711			11,942			(1,685		)	78,696
Net realized and unrealized gains	436,186			2,913			20,658			1,034			460,791
Fees and commission income	4,832			1,849			—			—			6,681
Other income	5,504			36			60			212			5,812
Corporate expenses	(16,570		)	(3,788		)	—			(8,697		)	(29,055		)
Interest income (expense)	(12,116		)	—			(475		)	1,555			(11,036		)
Net foreign exchange gains (losses)	3,618			825			(594		)	1			3,850
EARNINGS (LOSS) BEFORE INCOME TAXES	397,527			8,310			(37,852		)	(6,266		)	361,719
Income tax expense	(2,720		)	(685		)	(1,259		)	(85		)	(4,749		)
Earnings from equity method investments	8,584			—			188			—			8,772
NET EARNINGS (LOSS)	403,391			7,625			(38,923		)	(6,351		)	365,742
Net loss (earnings) attributable to noncontrolling interest	(2,646		)	(3,128		)	7,922			—			2,148
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR	400,745			4,497			(31,001		)	(6,351		)	367,890
Dividend on preferred shares	—			—			—			(9,139		)	(9,139		)
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$	400,745		$	4,497		$	(31,001	)	$	(15,490	)	$	358,751

Underwriting ratios:
Loss ratio				44.4		%	91.5		%
Acquisition expense ratio				35.5		%	24.2		%
Operating expense ratio				7.8		%	16.9		%
Combined ratio				87.7		%	132.6		%

Assets by Segment

Invested assets are managed on a subsidiary basis, and investment income and realized and unrealized gains (losses) on investments are recognized in each segment as earned. Our total assets by segment and for our other activities were as follows:



	March 31, 2020			December 31, 2019
Assets by Segment:
Non-life Run-off	$	15,438,588		$	15,775,409
Atrium	590,805			580,405
StarStone	3,627,036			3,522,353
Other	(524,920		)	(514,852		)
Total assets	$	19,131,509		$	19,363,315

Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2020

Accounting Policies [Abstract]

Basis of Preparation

Basis of Consolidation

Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, these financial statements reflect all adjustments consisting of normal recurring items considered necessary for a fair presentation under U.S. GAAP. The results of operations for any interim period are not necessarily indicative of results for the full year. These financial statements should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2019. All significant inter-company transactions and balances have been eliminated. In these notes, the terms "we," "us," "our," "Enstar," or "the Company" refer to Enstar Group Limited and its consolidated subsidiaries.

Reclassifications

Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications had no impact on net earnings.

Use of Estimates


•	liability for losses and loss adjustment expenses ("LAE");


•	reinsurance balances recoverable on paid and unpaid losses;


•	defendant asbestos and environmental liabilities and related insurance balances recoverable;


•	valuation allowances on reinsurance balances recoverable and deferred tax assets;


•	impairment charges, including credit allowances on investment securities classified as available-for-sale ("AFS"), and impairments on goodwill, intangible assets and deferred charge assets;


•	gross and net premiums written and net premiums earned;


•	fair value measurements of investments;


•	fair value estimates associated with accounting for acquisitions;


•	fair value estimates associated with loss portfolio transfer reinsurance agreements for which we have elected the fair value option; and

•

redeemable noncontrolling interests.

Short-term investments and fixed maturity investments

We perform a detailed analysis every reporting period to identify any credit losses on our investment portfolios not measured at fair value through net earnings.

and (4) whether it is more likely than not that we will be required to sell the security prior to an anticipated recovery in value.

Uncollectible debt securities are written off when we determine that no additional payments of principal or interest will be received.

Reinsurance Balances Recoverable on Paid and Unpaid Losses

Premiums Receivable and Unearned Premium Reserves

New Accounting Standards Adopted in 2020 and Recently Issued Accounting Pronouncements Not Yet Adopted

New Accounting Standards Adopted in 2020

ASU 2020-03 – Codification Improvements to Financial Instruments

ASUs 2016-13, 2018-19, 2019-04, 2019-05, 2019-10 and 2019-11, Financial Instruments – Credit Losses – Measurement of Credit Losses on Financial Instruments

•

$3.1 million related to our AFS debt securities whose fair values were less than their amortized cost basis.

Recently Issued Accounting Pronouncements Not Yet Adopted

ASU 2020-04 – Reference Rate Reform (ASC 848)

Investments (Tables)

3 Months Ended

Mar. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Marketable Securities



	March 31, 2020
	Short-term investments, trading		Short-term investments, AFS		Fixed maturities, trading		Fixed maturities, AFS		Fixed maturities, funds held - directly managed		Total
U.S. government and agency	$	766	$	34,582	$	186,693	$	203,637	$	94,255	$	519,933
U.K. government	3,675		3,337		63,420		29,573		—		100,005
Other government	11,022		334		490,111		83,007		19,540		604,014
Corporate	2,368		99,277		3,649,143		1,233,289		554,614		5,538,691
Municipal	418		1,370		98,341		15,676		49,025		164,830
Residential mortgage-backed	—		—		229,723		155,027		83,168		467,918
Commercial mortgage-backed	—		—		523,207		130,878		219,419		873,504
Asset-backed	—		—		404,181		289,086		61,608		754,875
Total fixed maturity and short-term investments	$	18,249	$	138,900	$	5,644,819	$	2,140,173	$	1,081,629	$	9,023,770



	December 31, 2019
	Short-term investments, trading		Short-term investments, AFS		Fixed maturities, trading		Fixed maturities, AFS		Fixed maturities, funds held - directly managed		Total
U.S. government and agency	$	—	$	111,583	$	219,194	$	298,729	$	106,537	$	736,043
U.K. government	24,411		1,069		122,012		14,280		—		161,772
Other government	21,958		387		575,018		84,760		20,734		702,857
Corporate	5,121		13,915		4,007,386		1,067,256		603,389		5,697,067
Municipal	—		1,381		102,554		14,491		49,456		167,882
Residential mortgage-backed	—		—		258,412		127,219		86,205		471,836
Commercial mortgage-backed	—		—		571,129		98,557		230,343		900,029
Asset-backed	—		—		490,624		208,097		76,681		775,402
Total fixed maturity and short-term investments	$	51,490	$	128,335	$	6,346,329	$	1,913,389	$	1,173,345	$	9,612,888

Summary of Amortized Cost and Estimated Fair Value of Fixed Maturities by Contractual Maturity



As of March 31, 2020	Amortized Cost		Fair Value		% of Total Fair Value
One year or less	$	502,300	$	497,009	5.5	%
More than one year through two years	754,996		747,837		8.3	%
More than two years through five years	2,209,294		2,156,740		23.9	%
More than five years through ten years	2,080,140		2,049,319		22.7	%
More than ten years	1,439,507		1,476,568		16.3	%
Residential mortgage-backed	466,964		467,918		5.2	%
Commercial mortgage-backed	894,859		873,504		9.7	%
Asset-backed	829,598		754,875		8.4	%
	$	9,177,658	$	9,023,770	100.0	%

Credit Ratings Company's Fixed Maturity and Short-Term Investments Available-for-Sale



	Amortized Cost		Fair Value		% of Total		AAA Rated			AA Rated			A Rated			BBB Rated			Non- Investment Grade			Not Rated

U.S. government and agency	$	488,708	$	519,933	5.8	%	$	519,933		$	—		$	—		$	—		$	—		$	—
U.K. government	100,716		100,005		1.1	%	538			99,467			—			—			—			—
Other government	618,746		604,014		6.7	%	268,626			136,721			63,097			111,636			20,478			3,456
Corporate	5,622,480		5,538,691		61.3	%	140,194			602,836			2,908,118			1,594,296			277,738			15,509
Municipal	155,587		164,830		1.8	%	16,425			77,511			49,068			21,826			—			—
Residential mortgage-backed	466,964		467,918		5.2	%	395,148			26,892			3,085			1,602			35,489			5,702
Commercial mortgage-backed	894,859		873,504		9.7	%	621,883			93,167			78,379			57,187			5,867			17,021
Asset-backed	829,598		754,875		8.4	%	421,823			64,782			122,025			71,799			10,352			64,094
Total	$	9,177,658	$	9,023,770	100.0	%	$	2,384,570		$	1,101,376		$	3,223,772		$	1,858,346		$	349,924		$	105,782
% of total fair value							26.4		%	12.2		%	35.7		%	20.6		%	3.9		%	1.2		%

Amortized Cost and Estimated Fair Values of Company's Fixed Maturity and Short-Term Investments Classified as Available-for-Sale

The amortized cost, unrealized gains and losses, allowance for credit losses and fair values of our short-term and fixed maturity investments classified as AFS as of March 31, 2020 were as follows:



					Gross Unrealized Losses
As of March 31, 2020	Amortized Cost		Gross Unrealized Gains		Non-Credit Related Losses			Allowance for Credit Losses⁽¹⁾			Fair Value
U.S. government and agency	$	230,450	$	7,783	$	(14	)	$	—		$	238,219
U.K. government	33,953		—		(1,043		)	—			32,910
Other government	84,302		1,416		(2,377		)	—			83,341
Corporate	1,374,000		5,680		(30,844		)	(16,270		)	1,332,566
Municipal	16,799		250		(3		)	—			17,046
Residential mortgage-backed	153,268		2,943		(1,184		)	—			155,027
Commercial mortgage-backed	137,641		744		(7,506		)	(1		)	130,878
Asset-backed	312,169		195		(23,278		)	—			289,086
	$	2,342,582	$	19,011	$	(66,249	)	$	(16,271	)	$	2,279,073

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

The amortized cost, unrealized gains and losses and fair values of our short-term and fixed maturity investments classified as AFS as of December 31, 2019 were as follows:



As of December 31, 2019	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses (Non-OTTI)			Fair Value
U.S. government and agency	$	410,842	$	77	$	(607	)	$	410,312
U.K. government	15,067		282		—			15,349
Other government	84,116		1,119		(88		)	85,147
Corporate	1,081,713		4,026		(4,568		)	1,081,171
Municipal	15,963		20		(111		)	15,872
Residential mortgage-backed	127,704		240		(725		)	127,219
Commercial mortgage-backed	98,928		38		(409		)	98,557
Asset-backed	208,121		169		(193		)	208,097
	$	2,042,454	$	5,971	$	(6,701	)	$	2,041,724

Summary of Investments Classified as Available-for-Sale in Unrealized Loss Position as Well as Aggregate Fair Value and Gross Unrealized Loss by Length of Time



	12 Months or Greater					Less Than 12 Months					Total
As of March 31, 2020	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency	$	—	$	—		$	1,399	$	(14	)	$	1,399	$	(14	)
U.K. government	—		—			32,909		(1,043		)	32,909		(1,043		)
Other government	992		(110		)	40,315		(2,267		)	41,307		(2,377		)
Corporate	2,390		(432		)	532,456		(10,287		)	534,846		(10,719		)
Municipal	—		—			473		(3		)	473		(3		)
Residential mortgage-backed	—		—			33,738		(1,184		)	33,738		(1,184		)
Commercial mortgage-backed	—		—			93,706		(7,460		)	93,706		(7,460		)
Asset-backed	—		—			264,205		(23,278		)	264,205		(23,278		)
Total fixed maturity and short-term investments	$	3,382	$	(542	)	$	999,201	$	(45,536	)	$	1,002,583	$	(46,078	)



	12 Months or Greater					Less Than 12 Months					Total
As of December 31, 2019	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency	$	—	$	—		$	222,643	$	(607	)	$	222,643	$	(607	)
Other government	1,080		(23		)	37,796		(65		)	38,876		(88		)
Corporate	2,754		(306		)	461,772		(4,262		)	464,526		(4,568		)
Municipal	128		—			12,046		(111		)	12,174		(111		)
Residential mortgage-backed	—		—			65,992		(725		)	65,992		(725		)
Commercial mortgage-backed	—		—			79,606		(409		)	79,606		(409		)
Asset-backed	—		—			129,014		(193		)	129,014		(193		)
Total fixed maturity and short-term investments	$	3,962	$	(329	)	$	1,008,869	$	(6,372	)	$	1,012,831	$	(6,701	)

Summary of Allowance for Credit Losses

The table below provides a reconciliation of the beginning and ending allowance for credit losses on our AFS debt securities for the three months ended March 31, 2020:



	Other government			Corporate			Commercial mortgage backed			Total
Allowance for credit losses, beginning of period	$	—		$	—		$	—		$	—
Cumulative effect of change in accounting principle	(22		)	(2,987		)	(50		)	(3,059		)
Allowances for credit losses on securities for which credit losses were not previously recorded	—			(13,681		)	—			(13,681		)
Reductions for securities sold during the period	—			369			—			369
Reductions in the allowance for credit losses on securities we either intend to sell or more likely than not, we will be required to sell before the recovery of their amortized cost basis	22			29			49			100
Allowance for credit loss, end of period	$	—		$	(16,270	)	$	(1	)	$	(16,271	)

Schedule of Equity Securities

The following table summarizes our equity investments classified as trading:



	March 31, 2020		December 31, 2019
Publicly traded equity investments in common and preferred stocks	$	240,932	$	327,875
Exchange-traded funds	130,906		133,047
Privately held equity investments in common and preferred stocks	270,012		268,799
	$	641,850	$	729,721

Other Investments

The following table summarizes our other investments carried at fair value:



	March 31, 2020		December 31, 2019
Hedge funds	$	1,055,448	$	1,121,904
Fixed income funds	463,717		481,039
Equity funds	320,046		410,149
Private equity funds	309,219		329,885
CLO equities	83,740		87,555
CLO equity funds	66,938		87,509
Private credit funds	20,473		—
Other	7,403		6,379
	$	2,326,984	$	2,524,420

The table below details the estimated date by which proceeds would be received if we had provided notice of our intent to redeem or initiated a sales process as of March 31, 2020:



	Less than 1 Year		1-2 years		2-3 years		More than 3 years		Not Eligible/ Restricted		Total		Redemption Frequency
Hedge funds	$	325,882	$	576,616	$	—	$	102,600	$	50,350	$	1,055,448	Monthly to Bi-annually
Fixed income funds	460,684		—		—		—		3,033		463,717		Daily to Quarterly
Equity funds	320,046		—		—		—		—		320,046		Daily to Quarterly
Private equity funds	—		—		—		—		309,219		309,219		N/A
CLO equities	83,740		—		—		—		—		83,740		N/A
CLO equity funds	47,938		—		19,000		—		—		66,938		Quarterly to Bi-annually
Private credit funds	—		—		—		—		20,473		20,473		N/A
Other	—		—		—		—		7,403		7,403		N/A
	$	1,238,290	$	576,616	$	19,000	$	102,600	$	390,478	$	2,326,984

Equity Method Investments

The following table summarizes our equity method investments:



	March 31, 2020						December 31, 2019
	Investment		Ownership %		Carrying Value		Investment		Ownership %		Carrying Value
Enhanzed Re	$	154,050	47.4	%	$	197,206	$	154,050	47.4	%	$	182,856
Citco	50,000		31.9	%	51,504		50,000		31.9	%	51,742
Monument	26,600		26.6	%	57,737		26,600		26.6	%	60,598
Clear Spring	11,210		20.0	%	10,952		11,210		20.0	%	10,645
Other	24,963		~30%		20,075		24,963		~30%		20,436
	$	266,823			$	337,474	$	266,823			$	326,277

Funds Held, Directly Managed, Carrying Values of Assets

The following table summarizes the components of the funds held - directly managed:



	March 31, 2020		December 31, 2019
Fixed maturity investments, trading	$	1,081,629	$	1,173,345
Cash and cash equivalents	51,209		10,296
Other assets	2,083		3,911
	$	1,134,921	$	1,187,552

Funds Held, Directly Managed, Fair Value to Amortized Cost

The following table summarizes the fixed maturity investment components of funds held - directly managed:



	March 31, 2020						December 31, 2019
	Funds held - Directly Managed - Fair Value Option		Funds held - Directly Managed - Variable Return		Total		Funds held - Directly Managed - Fair Value Option		Funds held - Directly Managed - Variable Return		Total
Fixed maturity investments, at amortized cost	$	164,425	$	895,214	$	1,059,639	$	185,859	$	940,194	$	1,126,053
Net unrealized gains (losses):
Change in fair value - fair value option accounting	2,754				2,754		5,438		—		5,438
Change in fair value - embedded derivative accounting			19,236		19,236		—		41,854		41,854
Fixed maturity investments within funds held - directly managed, at fair value	$	167,179	$	914,450	$	1,081,629	$	191,297	$	982,048	$	1,173,345

Major Categories of Net Investment Income

Major categories of net investment income are summarized as follows:



	Three Months Ended March 31,
	2020			2019
Fixed maturity investments	$	57,195		$	58,070
Short-term investments and cash and cash equivalents	2,794			3,860
Funds held	271			5,798
Funds held - directly managed	8,816			9,750
Investment income from fixed maturities and cash and cash equivalents	69,076			77,478
Equity investments	5,963			3,380
Other investments	7,505			2,114
Investment income from equities and other investments	13,468			5,494
Gross investment income	82,544			82,972
Investment expenses	(4,704		)	(4,276		)
Net investment income	$	77,840		$	78,696

Realized Gain (Loss) on Investments

Components of net realized and unrealized gains (losses) were as follows:



	Three Months Ended
	March 31,
	2020			2019
Net realized gains (losses) on sale:
Gross realized gains on fixed maturity securities, AFS	$	1,814		$	4
Gross realized losses on fixed maturity securities, AFS	(2,026		)	(65		)
Credit loss on fixed maturity securities, AFS	(13,212		)	—
Net realized gains (losses) on fixed maturity securities, trading	15,837			(611		)
Net realized gains (losses) on funds held - directly managed	512			(1,606		)
Net realized gains (losses) on equity investments	(1,007		)	2,548
Total net realized gains on sale	$	1,918		$	270
Net unrealized gains (losses):
Fixed maturity securities, trading	$	(261,008	)	$	209,467
Fixed maturity securities in funds held - directly managed portfolios	(25,302		)	38,962
Equity investments	(91,952		)	7,383
Other Investments	(258,132		)	204,709
Total net unrealized gains (losses)	(636,394		)	460,521
Net realized and unrealized gains (losses)	$	(634,476	)	$	460,791

Unrealized Gain (Loss) on Investments

Components of net realized and unrealized gains (losses) were as follows:



	Three Months Ended
	March 31,
	2020			2019
Net realized gains (losses) on sale:
Gross realized gains on fixed maturity securities, AFS	$	1,814		$	4
Gross realized losses on fixed maturity securities, AFS	(2,026		)	(65		)
Credit loss on fixed maturity securities, AFS	(13,212		)	—
Net realized gains (losses) on fixed maturity securities, trading	15,837			(611		)
Net realized gains (losses) on funds held - directly managed	512			(1,606		)
Net realized gains (losses) on equity investments	(1,007		)	2,548
Total net realized gains on sale	$	1,918		$	270
Net unrealized gains (losses):
Fixed maturity securities, trading	$	(261,008	)	$	209,467
Fixed maturity securities in funds held - directly managed portfolios	(25,302		)	38,962
Equity investments	(91,952		)	7,383
Other Investments	(258,132		)	204,709
Total net unrealized gains (losses)	(636,394		)	460,521
Net realized and unrealized gains (losses)	$	(634,476	)	$	460,791

Schedule of Restricted Assets

The carrying value of our restricted assets, including restricted cash of $345.1 million and $352.7 million, as of March 31, 2020 and December 31, 2019, respectively, was as follows:



	March 31, 2020		December 31, 2019
Collateral in trust for third party agreements	$	3,664,247	$	4,104,093
Assets on deposit with regulatory authorities	226,477		445,626
Collateral for secured letter of credit facilities	124,505		133,238
Funds at Lloyd's ⁽¹⁾	717,970		639,316
	$	4,733,199	$	5,322,273

Derivative and Hedging Instruments (Tables)

3 Months Ended

Mar. 31, 2020

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Estimated Fair Value and Unrealized Gains (Losses) on Derivative Instruments



	March 31, 2020						December 31, 2019
			Fair Value						Fair Value
	Gross Notional Amount		Assets		Liabilities		Gross Notional Amount		Assets		Liabilities
Foreign currency forward - AUD	$	56,149	$	4,269	$	—	$	64,620	$	52	$	2,033
Foreign currency forward - EUR	103,127		194		943		112,284		246		1,635
Foreign currency forward - GBP	297,582		13,192		—		318,387		344		7,784
Total qualifying hedges	$	456,858	$	17,655	$	943	$	495,291	$	642	$	11,452



	Amount of Gains (Losses) Deferred in AOCI
	Three Months Ended March 31,
	2020		2019
Foreign currency forward - AUD	$	8,471	$	(327	)
Foreign currency forward - EUR	2,635		1,855
Foreign currency forward - GBP	20,812		—
Net gains on qualifying derivative hedges	$	31,918	$	1,528



	March 31, 2020						December 31, 2019
			Fair Value						Fair Value
	Gross Notional Amount		Assets		Liabilities		Gross Notional Amount		Assets		Liabilities
Foreign currency forward - AUD	$	32,103	$	3,088	$	608	$	913	$	839	$	892
Foreign currency forward - CAD	50,754		3,419		1		66,266		10		1,482
Foreign currency forward - EUR	52,660		173		1,672		74,444		507		1,440
Foreign currency forward - GBP	24,427		972		713		11,940		13		292
Total non-qualifying hedges	$	159,944	$	7,652	$	2,994	$	153,563	$	1,369	$	4,106

The following table presents the amounts of the net gains (losses) included in earnings related to our non-qualifying foreign currency forward contracts:



	Gains (Losses) on non-qualifying-hedges included in net earnings
	Three Months Ended March 31,
	2020		2019
Foreign currency forward - AUD	$	2,533	$	(765	)
Foreign currency forward - CAD	4,996		1
Foreign currency forward - EUR	1,176		1,205
Foreign currency forward - GBP	576		(4,059		)
Net gains (losses) on non-qualifying hedges	$	9,281	$	(3,618	)

- Definition

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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+ Details

Reinsurance Balances Recoverable on Paid and Unpaid Losses (Tables)

3 Months Ended

Mar. 31, 2020

Insurance [Abstract]

Summary of Reinsurance Reserves Recoverable and Uncollectible Reinsurance Balances Recoverable

The following tables provide the total reinsurance balances recoverable on paid and unpaid losses:



	March 31, 2020
	Non-life Run-off			Atrium		StarStone			Total
Recoverable from reinsurers on unpaid:
Outstanding losses	$	957,961		$	8,140	$	321,921		$	1,288,022
IBNR	602,508			24,781		263,222			890,511
Fair value adjustments - acquired companies	(13,353		)	514		(1,678		)	(14,517		)
Fair value adjustments - fair value option	(93,935		)	—		—			(93,935		)
ULAE	7,827			—		—			7,827
Total reinsurance reserves recoverable	1,461,008			33,435		583,465			2,077,908
Paid losses recoverable	137,210			1,181		103,478			241,869
Total	$	1,598,218		$	34,616	$	686,943		$	2,319,777

Reconciliation to Consolidated Balance Sheet:
Reinsurance balances recoverable on paid and unpaid losses	$	944,822		$	34,616	$	686,943		$	1,666,381
Reinsurance balances recoverable on paid and unpaid losses - fair value option	653,396			—		—			653,396
Total	$	1,598,218		$	34,616	$	686,943		$	2,319,777



	December 31, 2019
	Non-life Run-off			Atrium		StarStone			Total
Recoverable from reinsurers on unpaid:
Outstanding losses	$	972,293		$	9,011	$	328,009		$	1,309,313
IBNR	673,059			19,286		211,404			903,749
Fair value adjustments - acquired companies	(13,652		)	519		(2,122		)	(15,255		)
Fair value adjustments - fair value option	(88,086		)	—		—			(88,086		)
Total reinsurance reserves recoverable	1,543,614			28,816		537,291			2,109,721
Paid losses recoverable	181,375			1,541		87,253			270,169
Total	$	1,724,989		$	30,357	$	624,544		$	2,379,890

Reconciliation to Consolidated Balance Sheet:
Reinsurance balances recoverable on paid and unpaid losses	$	1,029,471		$	30,357	$	624,544		$	1,684,372
Reinsurance balances recoverable on paid and unpaid losses - fair value option	695,518			—		—			695,518
Total	$	1,724,989		$	30,357	$	624,544		$	2,379,890



	March 31, 2020
	Gross		Allowance for estimated uncollectible reinsurance		Net		Provisions as a % of Gross
Reinsurers rated A- or above	$	1,853,658	$	42,759	$	1,810,899	2.3	%
Reinsurers rated below A-, secured	478,752		—		478,752		—	%
Reinsurers rated below A-, unsecured	130,694		100,568		30,126		76.9	%
Total	$	2,463,104	$	143,327	$	2,319,777	5.8	%



	December 31, 2019
	Gross		Allowance for estimated uncollectible reinsurance		Net		Provisions as a % of Gross
Reinsurers rated A- or above	$	1,904,268	$	43,427	$	1,860,841	2.3	%
Reinsurers rated below A-, secured	487,608		—		487,608		—	%
Reinsurers rated below A-, unsecured	135,653		104,212		31,441		76.8	%
Total	$	2,527,529	$	147,639	$	2,379,890	5.8	%

The following table provides a summary of premiums written and earned by segment and for our other activities:



	Three Months Ended March 31,
	2020						2019
	Premiums Written			Premiums Earned			Premiums Written			Premiums Earned
Non-life Run-off
Gross	$	327		$	18,078		$	(20,877	)	$	83,966
Ceded	1,849			(2,048		)	1,699			(7,292		)
Net	$	2,176		$	16,030		$	(19,178	)	$	76,674
Atrium
Gross	$	57,837		$	47,833		$	53,985		$	43,386
Ceded	(9,139		)	(5,463		)	(7,486		)	(4,633		)
Net	$	48,698		$	42,370		$	46,499		$	38,753
StarStone
Gross	$	279,854		$	258,107		$	251,373		$	268,264
Ceded	(90,819		)	(59,947		)	(56,772		)	(55,002		)
Net	$	189,035		$	198,160		$	194,601		$	213,262
Other
Gross	$	(3,885	)	$	2,673		$	864		$	6,673
Ceded	664			664			(19		)	(75		)
Net	$	(3,221	)	$	3,337		$	845		$	6,598
Total
Gross	$	334,133		$	326,691		$	285,345		$	402,289
Ceded	(97,445		)	(66,794		)	(62,578		)	(67,002		)
Total	$	236,688		$	259,897		$	222,767		$	335,287

Reinsurance Balances Recoverable by Reinsurer



	March 31, 2020
	Non-life Run-off		Atrium		StarStone		Total		% of Total
Top 10 reinsurers	$	1,075,150	$	25,328	$	430,788	$	1,531,266	66.0	%
Other reinsurers > $1 million	510,504		8,742		253,127		772,373		33.3	%
Other reinsurers < $1 million	12,564		546		3,028		16,138		0.7	%
Total	$	1,598,218	$	34,616	$	686,943	$	2,319,777	100.0	%



	December 31, 2019
	Non-life Run-off		Atrium		StarStone		Total		% of Total
Top 10 reinsurers	$	1,154,110	$	22,051	$	388,171	$	1,564,332	65.7	%
Other reinsurers > $1 million	551,636		7,761		233,871		793,268		33.4	%
Other reinsurers < $1 million	19,243		545		2,502		22,290		0.9	%
Total	$	1,724,989	$	30,357	$	624,544	$	2,379,890	100.0	%



	March 31, 2020		December 31, 2019
Information regarding top ten reinsurers:
Number of top 10 reinsurers rated A- or better	8		8
Number of top 10 non-rated reinsurers ⁽¹⁾	2		2

Reinsurers rated A- or better in top 10	$	1,260,977	$	1,292,207
Collaterized non-rated reinsurers in top 10 ⁽¹⁾	270,289		272,125
Total top 10 reinsurance recoverables	$	1,531,266	$	1,564,332

Single reinsurers that represent 10% or more of total reinsurance balance recoverables as of March 31, 2020:

Hannover Ruck SE ⁽²⁾	$	264,424	$	261,295
Lloyd's Syndicates ⁽³⁾	$	412,790	$	411,030

⁽²⁾ Hannover Ruck SE is rated AA- by Standard & Poor’s and A+ by A.M. Best.

⁽³⁾ Lloyd's Syndicates are rated A+ by Standard & Poor's and A by A.M. Best.

Reconciliation for Reinsurance Recoverable, Allowance for Credit Loss

The table below provides a reconciliation of the beginning and ending allowance for estimated uncollectible reinsurance balances for the three months ended March 31, 2020:



	Three Months Ended
	March 31, 2020
Allowance for estimated uncollectible reinsurance, beginning of period	$	147,639
Cumulative effect of change in accounting principle	(195		)
Current period change in the allowance	(4,117		)
Allowance for estimated uncollectible reinsurance, end of period	$	143,327

Deferred Charge Assets (Tables)

3 Months Ended

Mar. 31, 2020

Insurance [Abstract]

Deferred Policy Acquisition Costs

The following table presents a reconciliation of the deferred charge assets:



	Three Months Ended March 31,
	2020			2019
Beginning carrying value	$	272,462		$	86,585
Recorded during the period	—			20,632
Amortization	(14,630		)	(7,063		)
Ending carrying value	$	257,832		$	100,154

Losses and Loss Adjustment Expenses (Tables)

3 Months Ended

Mar. 31, 2020

Insurance [Abstract]

Total Losses and Loss Adjustment Expense Liabilities, and Reconciliation of Beginning and Ending Balances

The following tables summarize the liability for losses and LAE by segment and for our other activities:



	March 31, 2020
	Non-life Run-off			Atrium		StarStone			Other		Total
Outstanding losses	$	4,392,560		$	86,712	$	831,996		$	9,764	$	5,321,032
IBNR	3,937,751			150,666		1,086,293			12,749		5,187,459
Fair value adjustments - acquired companies	(161,040		)	3,833		(413		)	—		(157,620		)
Fair value adjustments - fair value option	(274,642		)	—		—			—		(274,642		)
ULAE	322,221			2,399		29,138			—		353,758
Total	$	8,216,850		$	243,610	$	1,947,014		$	22,513	$	10,429,987

Reconciliation to Consolidated Balance Sheet:
Loss and loss adjustment expenses	$	5,871,307		$	243,610	$	1,947,014		$	22,513	$	8,084,444
Loss and loss adjustment expenses, at fair value	2,345,543			—		—			—		2,345,543
Total	$	8,216,850		$	243,610	$	1,947,014		$	22,513	$	10,429,987



	December 31, 2019
	Non-life Run-off			Atrium		StarStone			Other		Total
Outstanding losses	$	4,407,082		$	89,141	$	888,794		$	9,512	$	5,394,529
IBNR	3,945,407			136,543		962,353			13,565		5,057,868
Fair value adjustments - acquired companies	(170,689		)	3,700		(522		)	—		(167,511		)
Fair value adjustments - fair value option	(217,933		)	—		—			—		(217,933		)
ULAE	331,494			2,288		28,503			—		362,285
Total	$	8,295,361		$	231,672	$	1,879,128		$	23,077	$	10,429,238

Reconciliation to Consolidated Balance Sheet:
Loss and loss adjustment expenses	$	5,674,239		$	231,672	$	1,879,128		$	23,077	$	7,808,116
Loss and loss adjustment expenses, at fair value	2,621,122			—		—			—		2,621,122
Total	$	8,295,361		$	231,672	$	1,879,128		$	23,077	$	10,429,238

The table below provides a consolidated reconciliation of the beginning and ending liability for losses and LAE:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	10,429,238		$	9,409,504
Less: reinsurance reserves recoverable	2,109,721			1,867,841
Less: deferred charge assets on retroactive reinsurance	272,462			86,585
Less: cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible reinsurance balances ⁽¹⁾	195			—
Net balance as of beginning of period	8,046,860			7,455,078
Net incurred losses and LAE:
Current period	181,203			217,266
Prior periods	(73,309		)	95,138
Total net incurred losses and LAE	107,894			312,404
Net paid losses:
Current period	(6,582		)	(28,029		)
Prior periods	(378,992		)	(461,605		)
Total net paid losses	(385,574		)	(489,634		)
Effect of exchange rate movement	(146,083		)	19,679
Assumed business	471,150			620,418
Net balance as of March 31	8,094,247			7,917,945
Plus: reinsurance reserves recoverable⁽²⁾	2,077,908			2,077,923
Plus: deferred charge assets on retroactive reinsurance	257,832			100,154
Balance as of March 31	$	10,429,987		$	10,096,022

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible reinsurance.

The table below provides a reconciliation of the beginning and ending liability for losses and LAE for the Non-life Run-off segment:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	8,295,361		$	7,540,662
Less: reinsurance reserves recoverable	1,543,614			1,366,123
Less: deferred charge assets on retroactive insurance	272,462			86,585
Plus: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance ⁽¹⁾	703			—
Net balance as of beginning of period	6,479,988			6,087,954
Net incurred losses and LAE:
Current period	7,849			49,071
Prior periods	(69,883		)	46,111
Total net incurred losses and LAE	(62,034		)	95,182
Net paid losses:
Current period	(1,240		)	(18,014		)
Prior periods	(257,726		)	(331,055		)
Total net paid losses	(258,966		)	(349,069		)
Effect of exchange rate movement	(132,128		)	20,689
Assumed business	471,150			620,418
Net balance as of March 31	6,498,010			6,475,174
Plus: reinsurance reserves recoverable ⁽²⁾	1,461,008			1,579,646
Plus: deferred charge assets on retroactive reinsurance	257,832			100,154
Balance as of March 31	$	8,216,850		$	8,154,974

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible reinsurance.

The table below provides a reconciliation of the beginning and ending liability for losses and LAE for the Atrium segment:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	231,672		$	241,284
Less: reinsurance reserves recoverable	28,816			38,768
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance ⁽¹⁾	851			—
Net balance as of beginning of period	202,005			202,516
Net incurred losses and LAE:
Current period	27,904			18,237
Prior periods	512			(1,023		)
Total net incurred losses and LAE	28,416			17,214
Net paid losses:
Current period	(4,285		)	(7,893		)
Prior periods	(12,723		)	(14,420		)
Total net paid losses	(17,008		)	(22,313		)
Effect of exchange rate movement	(3,238		)	281
Net balance as of March 31	210,175			197,698
Plus: reinsurance reserves recoverable ⁽²⁾	33,435			31,682
Balance as of March 31	$	243,610		$	229,380

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible reinsurance.

The table below provides a reconciliation of the beginning and ending liability for losses and LAE for our StarStone segment:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	1,879,128		$	1,608,697
Less: reinsurance reserves recoverable	537,291			462,950
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance ⁽¹⁾	47			—
Net balance as of beginning of period	1,341,790			1,145,747
Net incurred losses and LAE:
Current period	142,105			144,950
Prior periods	(3,075		)	50,102
Total net incurred losses and LAE	139,030			195,052
Net paid losses:
Current period	(1,027		)	(1,792		)
Prior periods	(105,527		)	(113,625		)
Total net paid losses	(106,554		)	(115,417		)
Effect of exchange rate movement	(10,717		)	(1,291		)
Net balance as of March 31	1,363,549			1,224,091
Plus: reinsurance reserves recoverable ⁽²⁾	583,465			466,595
Balance as of March 31	$	1,947,014		$	1,690,686

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible reinsurance.

Schedule of Incurred Losses

The tables below provide the components of net incurred losses and LAE by segment and for our other activities:



	Three Months Ended March 31, 2020
	Non-life Run-off			Atrium		StarStone			Other			Total
Net losses paid	$	258,966		$	17,008	$	106,554		$	3,046		$	385,574
Net change in case and LAE reserves	(174,580		)	139		(43,192		)	252			(217,381		)
Net change in IBNR reserves	(104,397		)	11,131		75,262			(816		)	(18,820		)
Increase (reduction) in estimates of net ultimate losses	(20,011		)	28,278		138,624			2,482			149,373
Increase (reduction) in provisions for unallocated LAE	(7,479		)	—		741			—			(6,738		)
Amortization of deferred charge assets	14,630			—		—			—			14,630
Amortization of fair value adjustments	9,063			138		(335		)	—			8,866
Changes in fair value - fair value option	(58,237		)	—		—			—			(58,237		)
Net incurred losses and LAE	$	(62,034	)	$	28,416	$	139,030		$	2,482		$	107,894



	Three Months Ended March 31, 2019
	Non-life Run-off			Atrium			StarStone			Other		Total
Net losses paid	$	349,069		$	22,313		$	115,417		$	2,835	$	489,634
Net change in case and LAE reserves	(77,701		)	(413		)	2,056			595		(75,463		)
Net change in IBNR reserves	(232,895		)	(5,817		)	76,424			1,526		(160,762		)
Increase in estimates of net ultimate losses	38,473			16,083			193,897			4,956		253,409
Increase (reduction) in provisions for unallocated LAE	(15,175		)	—			1,348			—		(13,827		)
Amortization of deferred charge assets	7,064			—			—			—		7,064
Amortization of fair value adjustments	8,779			1,131			(193		)	—		9,717
Changes in fair value - fair value option	56,041			—			—			—		56,041
Net incurred losses and LAE	$	95,182		$	17,214		$	195,052		$	4,956	$	312,404

Net incurred losses and LAE in the Non-life Run-off segment were as follows:



	Three Months Ended March 31,
	2020								2019
	Prior Period			Current Period		Total			Prior Period			Current Period		Total
Net losses paid	$	257,726		$	1,240	$	258,966		$	331,055		$	18,014	$	349,069
Net change in case and LAE reserves	(176,252		)	1,672		(174,580		)	(97,573		)	19,872		(77,701		)
Net change in IBNR reserves	(109,334		)	4,937		(104,397		)	(243,815		)	10,920		(232,895		)
Increase (reduction) in estimates of net ultimate losses	(27,860		)	7,849		(20,011		)	(10,333		)	48,806		38,473
Increase (reduction) in provisions for unallocated LAE	(7,479		)	—		(7,479		)	(15,440		)	265		(15,175		)
Amortization of deferred charge assets	14,630			—		14,630			7,064			—		7,064
Amortization of fair value adjustments	9,063			—		9,063			8,779			—		8,779
Changes in fair value - fair value option	(58,237		)	—		(58,237		)	56,041			—		56,041
Net incurred losses and LAE	$	(69,883	)	$	7,849	$	(62,034	)	$	46,111		$	49,071	$	95,182

Net incurred losses and LAE in the Atrium segment were as follows:



	Three Months Ended March 31,
	2020							2019
	Prior Period			Current Period		Total		Prior Period			Current Period		Total
Net losses paid	$	12,723		$	4,285	$	17,008	$	14,420		$	7,893	$	22,313
Net change in case and LAE reserves	(3,034		)	3,173		139		(6,342		)	5,929		(413		)
Net change in IBNR reserves	(9,315		)	20,446		11,131		(10,232		)	4,415		(5,817		)
Increase (reduction) in estimates of net ultimate losses	374			27,904		28,278		(2,154		)	18,237		16,083
Amortization of fair value adjustments	138			—		138		1,131			—		1,131
Net incurred losses and LAE	$	512		$	27,904	$	28,416	$	(1,023	)	$	18,237	$	17,214

Net incurred losses and LAE in the StarStone segment were as follows:



	Three Months Ended March 31,
	2020								2019
	Prior Period			Current Period		Total			Prior Period			Current Period		Total
Net losses paid	$	105,527		$	1,027	$	106,554		$	113,625		$	1,792	$	115,417
Net change in case and LAE reserves	(48,693		)	5,501		(43,192		)	(8,824		)	10,880		2,056
Net change in IBNR reserves	(57,969		)	133,231		75,262			(52,834		)	129,258		76,424
Increase (reduction) in estimates of net ultimate losses	(1,135		)	139,759		138,624			51,967			141,930		193,897
Increase (reduction) in provisions for unallocated LAE	(1,605		)	2,346		741			(1,672		)	3,020		1,348
Amortization of fair value adjustments	(335		)	—		(335		)	(193		)	—		(193		)
Net incurred losses and LAE	$	(3,075	)	$	142,105	$	139,030		$	50,102		$	144,950	$	195,052

Defendant Asbestos and Environmental Liabilities (Tables)

3 Months Ended

Mar. 31, 2020

Liability for Asbestos and Environmental Claims [Abstract]

Schedule of Liability for Asbestos and Liability Claims

The carrying value of the asbestos and environmental liabilities, insurance recoveries, future estimated expenses and the fair value adjustments related to DCo and Morse TEC as of March 31, 2020 and December 31, 2019 were as follows:



	March 31, 2020			December 31, 2019
Defendant asbestos and environmental liabilities:
Defendant asbestos liabilities	$	1,068,620		$	1,100,593
Defendant environmental liabilities	10,146			10,279
Estimated future expenses	49,607			51,637
Fair value adjustments	(305,657		)	(314,824		)
Defendant asbestos and environmental liabilities	822,716			847,685

Insurance balances recoverable:
Insurance recoveries related to defendant asbestos and environmental liabilities	532,653			549,593
Fair value adjustments	(97,040		)	(100,738		)
Insurance balances recoverable	435,613			448,855

Net liabilities relating to defendant asbestos and environmental exposures	$	387,103		$	398,830

Reconciliation of Asbestos and Environmental Liabilities

The table below provides a consolidated reconciliation of the beginning and ending liability for defendant asbestos and environmental exposures for the three months ended March 31, 2020 and 2019:



	Three Months Ended
	March 31,
	2020			2019
Balance as of beginning of period	$	847,685		$	203,320
Less: Insurance balances recoverable	448,855			135,808
Plus: Cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible insurance balances ⁽¹⁾	3,167			—
Net balance as of beginning of period	401,997			67,512
Total net paid claims	6,581			2,751
Amounts recorded in other (income) expense:
Change in estimate of ultimate net liabilities	(24,915		)	(1,159		)
Increase (reduction) in estimated future expenses	(2,028		)	(2,125		)
Amortization of fair value adjustments	5,468			101
Total other expense (income)	(21,475		)	(3,183		)
Net balance as at March 31	387,103			67,080
Plus: Insurance balances recoverable ⁽²⁾	435,613			130,432
Balance as at March 31	$	822,716		$	197,512

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

⁽²⁾Net of allowance for estimated uncollectible insurance balances.

Reconciliation of Allowance for Estimated Uncollectible Insurance Balances



	Three Months Ended
	March 31, 2020
Allowance for estimated uncollectible insurance balances, beginning of period	$	3,818
Cumulative effect of change in accounting principle	3,167
Allowance for estimated uncollectible insurance balances, end of period	$	6,985

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Categorized Investments Recorded at Fair Value among Levels

We have categorized our assets and liabilities that are recorded at fair value on a recurring basis among levels based on the observability of inputs, or at fair value using NAV per share (or its equivalent) as follows:



	March 31, 2020
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value Based on NAV as Practical Expedient		Total Fair Value
Investments:
Short-term and fixed maturity investments:
U.S. government and agency	$	—	$	519,933	$	—	$	—	$	519,933
U.K. government	—		100,005		—		—		100,005
Other government	—		604,014		—		—		604,014
Corporate	—		5,538,691		—		—		5,538,691
Municipal	—		164,830		—		—		164,830
Residential mortgage-backed	—		467,918		—		—		467,918
Commercial mortgage-backed	—		873,504		—		—		873,504
Asset-backed	—		754,875		—		—		754,875
	$	—	$	9,023,770	$	—	$	—	$	9,023,770

Other assets included within funds held - directly managed	—		53,292		—		—		53,292

Equities:
Publicly traded equity investments	$	210,419	$	30,513	$	—	$	—	$	240,932
Exchange-traded funds	130,906		—		—		—		130,906
Privately held equity investments	—		—		270,012		—		270,012
	$	341,325	$	30,513	$	270,012	$	—	$	641,850

Other investments:
Hedge funds	$	—	$	—	$	—	$	1,055,448	$	1,055,448
Fixed income funds	—		325,066		—		138,651		463,717
Equity funds	—		76,591		—		243,455		320,046
Private equity funds	—		—		—		309,219		309,219
CLO equities	—		83,740		—		—		83,740
CLO equity funds	—		—		—		66,938		66,938
Private credit funds	—		—		—		20,473		20,473
Other	—		—		514		6,889		7,403
	$	—	$	485,397	$	514	$	1,841,073	$	2,326,984
Total Investments	$	341,325	$	9,592,972	$	270,526	$	1,841,073	$	12,045,896

Cash and cash equivalents	$	204,294	$	122,243	$	—	$	—	$	326,537

Reinsurance balances recoverable on paid and unpaid losses:	$	—	$	—	$	653,396	$	—	$	653,396

Other Assets:
Derivatives qualifying as hedges	$	—	$	17,655	$	—	$	—	$	17,655
Derivatives not qualifying as hedges	—		7,652		—		—		7,652
Derivative instruments	$	—	$	25,307	$	—	$	—	$	25,307

Losses and LAE:	$	—	$	—	$	2,345,543	$	—	$	2,345,543

Other Liabilities:
Derivatives qualifying as hedges	$	—	$	943	$	—	$	—	$	943
Derivatives not qualifying as hedges	—		2,994		—		—		2,994
Derivative instruments	$	—	$	3,937	$	—	$	—	$	3,937



	December 31, 2019
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value Based on NAV as Practical Expedient		Total Fair Value
Investments:
Short-term and fixed maturity investments:
U.S. government and agency	$	—	$	736,043	$	—	$	—	$	736,043
U.K government	—		161,772		—		—		161,772
Other government	—		702,857		—		—		702,857
Corporate	—		5,697,067		—		—		5,697,067
Municipal	—		167,882		—		—		167,882
Residential mortgage-backed	—		471,836		—		—		471,836
Commercial mortgage-backed	—		900,029		—		—		900,029
Asset-backed	—		775,402		—		—		775,402
	$	—	$	9,612,888	$	—	$	—	$	9,612,888

Other assets included within funds held - directly managed	$	—	$	14,207	$	—	$	—	$	14,207

Equities:
Publicly traded equity investments	$	297,310	$	30,565	$	—	$	—	$	327,875
Exchange-traded funds	133,047		—		—		—		133,047
Privately held equity investments	—		—		268,799		—		268,799
	$	430,357	$	30,565	$	268,799	$	—	$	729,721

Other investments:
Hedge funds	$	—	$	—	$	—	$	1,121,904	$	1,121,904
Fixed income funds	—		398,143		—		82,896		481,039
Equity funds	—		111,040		—		299,109		410,149
Private equity funds	—		—		—		329,885		329,885
CLO equities	—		—		87,555		—		87,555
CLO equity funds	—		—		—		87,509		87,509
Other	—		34		314		6,031		6,379
	$	—	$	509,217	$	87,869	$	1,927,334	$	2,524,420
Total Investments	$	430,357	$	10,166,877	$	356,668	$	1,927,334	$	12,881,236

Cash and cash equivalents	$	173,892	$	222,191	$	—	$	—	$	396,083

Reinsurance balances recoverable on paid and unpaid losses:	$	—	$	—	$	695,518	$	—	$	695,518

Other Assets:
Derivatives qualifying as hedges	$	—	$	642	$	—	$	—	$	642
Derivatives not qualifying as hedges	—		1,369		—		—		1,369
Derivative instruments	$	—	$	2,011	$	—	$	—	$	2,011

Losses and LAE:	$	—	$	—	$	2,621,122	$	—	$	2,621,122

Other Liabilities:
Derivatives qualifying as hedges	$	—	$	11,452	$	—	$	—	$	11,452
Derivatives not qualifying as hedges	—		4,106		—		—		4,106
Derivative instruments	$	—	$	15,558	$	—	$	—	$	15,558

Reconciliation for Assets Measured at Fair Value on a Recurring Basis

The following tables present a reconciliation of the beginning and ending balances for all investments measured at fair value on a recurring basis using Level 3 inputs:



	Three Months Ended March 31, 2020
	Privately-held Equities			Other Investments			Total
	Privately-held Equities			Other Investments			Total
Beginning fair value	$	268,799		$	87,869		$	356,668
Purchases	1,358			37,292			38,650
Sales	—			(539		)	(539		)
Total realized and unrealized losses	(145		)	(40,368		)	(40,513		)
Transfer out of Level 3 into Level 2	—			(83,740		)	(83,740		)
Ending fair value	$	270,012		$	514		$	270,526



	Three Months Ended March 31, 2019
	Fixed maturity investments									Privately-held Equities		Other Investments		Total
	Corporate			Commercial mortgage-backed			Asset-backed			Privately-held Equities		Other Investments		Total
Beginning fair value	$	37,386		$	7,389		$	9,121		$	228,710	$	39,367	$	321,973
Sales	(2,660		)	(608		)	(321		)	—		—		(3,589		)
Total realized and unrealized gains	257			62			737			—		2,380		3,436
Transfer into Level 3 from Level 2	387			—			6,225			—		—		6,612
Transfer out of Level 3 into Level 2	(32,198		)	(6,843		)	(6,462		)	—		—		(45,503		)
Ending fair value	$	3,172		$	—		$	9,300		$	228,710	$	41,747	$	282,929

The following table presents a reconciliation of the beginning and ending balances for all insurance contracts measured at fair value on a recurring basis using Level 3 inputs:



	Three Months Ended March 31,
	2020									2019
	Liability for losses and LAE			Reinsurance balances recoverable			Net			Liability for losses and LAE			Reinsurance balances recoverable			Net
Beginning fair value	$	2,621,122		$	695,518		$	1,925,604		$	2,874,055		$	739,591		$	2,134,464
Assumed business	4,975			—			4,975			—			—			—
Incurred losses and LAE:
Reduction in estimates of ultimate losses	(14,439		)	(3,171		)	(11,268		)	(7,154		)	(3,486		)	(3,668		)
Reduction in unallocated LAE	(6,413		)	—			(6,413		)	(4,341		)	—			(4,341		)
Change in fair value	(64,804		)	(6,567		)	(58,237		)	77,461			21,420			56,041
Total incurred losses and LAE	(85,656		)	(9,738		)	(75,918		)	65,966			17,934			48,032
Paid losses	(81,163		)	(16,114		)	(65,049		)	(115,860		)	(27,242		)	(88,618		)
Effect of exchange rate movements	(113,735		)	(16,270		)	(97,465		)	23,632			4,974			18,658
Ending fair value	$	2,345,543		$	653,396		$	1,692,147		$	2,847,793		$	735,257		$	2,112,536

Changes in fair value in the table above are included in net incurred losses and LAE in our consolidated statements of earnings.

The following table presents the components of the net change in fair value:



	Three Months Ended March 31,
	2020			2019
Changes in fair value due to changes in:
Duration	$	4,148		$	9,047
Corporate bond yield	(64,092		)	46,994
Weighted cost of capital	(5,048		)	—
Risk cost of capital	6,755			—
Change in fair value	$	(58,237	)	$	56,041

Valuation Inputs and Techniques

The table below presents the quantitative information related to the fair value measurements for investments measured at fair value on a recurring basis using Level 3 inputs:



Qualitative Information about Level 3 Fair Value Measurements
	Fair Value as of March 31, 2020		Valuation Techniques	Unobservable Input	Range (Average) ⁽¹⁾
	(in millions of U.S. dollars)
Privately held equity investments	$	270.0	Transactional value	Implied price at recent purchase transaction	13.50 - 13.85
Privately held equity investments	$	270.0	Cost as approximation of fair value	Cost as approximation of fair value

⁽¹⁾ The average represents the arithmetic average of the inputs and is not weighted by the relative fair value.

Reconciliation for Liabilities Measured at Fair Value on a Recurring Basis

The following table presents a reconciliation of the beginning and ending balances for all insurance contracts measured at fair value on a recurring basis using Level 3 inputs:



	Three Months Ended March 31,
	2020									2019
	Liability for losses and LAE			Reinsurance balances recoverable			Net			Liability for losses and LAE			Reinsurance balances recoverable			Net
Beginning fair value	$	2,621,122		$	695,518		$	1,925,604		$	2,874,055		$	739,591		$	2,134,464
Assumed business	4,975			—			4,975			—			—			—
Incurred losses and LAE:
Reduction in estimates of ultimate losses	(14,439		)	(3,171		)	(11,268		)	(7,154		)	(3,486		)	(3,668		)
Reduction in unallocated LAE	(6,413		)	—			(6,413		)	(4,341		)	—			(4,341		)
Change in fair value	(64,804		)	(6,567		)	(58,237		)	77,461			21,420			56,041
Total incurred losses and LAE	(85,656		)	(9,738		)	(75,918		)	65,966			17,934			48,032
Paid losses	(81,163		)	(16,114		)	(65,049		)	(115,860		)	(27,242		)	(88,618		)
Effect of exchange rate movements	(113,735		)	(16,270		)	(97,465		)	23,632			4,974			18,658
Ending fair value	$	2,345,543		$	653,396		$	1,692,147		$	2,847,793		$	735,257		$	2,112,536

Changes in fair value in the table above are included in net incurred losses and LAE in our consolidated statements of earnings.

The following table presents the components of the net change in fair value:



	Three Months Ended March 31,
	2020			2019
Changes in fair value due to changes in:
Duration	$	4,148		$	9,047
Corporate bond yield	(64,092		)	46,994
Weighted cost of capital	(5,048		)	—
Risk cost of capital	6,755			—
Change in fair value	$	(58,237	)	$	56,041

Quantitative Information

Below is a summary of the quantitative information regarding the significant observable and unobservable inputs used in the internal model to determine fair value on a recurring basis:



		March 31, 2020	December 31, 2019
Valuation Technique	Unobservable (U) and Observable (O) Inputs	Weighted Average	Weighted Average
Internal model	Corporate bond yield (O)	A rated	A rated
Internal model	Credit spread for non-performance risk (U)	0.2%	0.2%
Internal model	Risk cost of capital (U)	5.1%	5.1%
Internal model	Weighted average cost of capital (U)	8.25%	8.5%
Internal model	Duration - liability (U)	7.91 years	7.82 years
Internal model	Duration - reinsurance balances recoverable (U)	8.74 years	8.68 years

Premiums Written and Earned (Tables)

3 Months Ended

Mar. 31, 2020

Insurance [Abstract]

Schedule of Net Premiums Written and Earned

The following tables provide the total reinsurance balances recoverable on paid and unpaid losses:



	March 31, 2020
	Non-life Run-off			Atrium		StarStone			Total
Recoverable from reinsurers on unpaid:
Outstanding losses	$	957,961		$	8,140	$	321,921		$	1,288,022
IBNR	602,508			24,781		263,222			890,511
Fair value adjustments - acquired companies	(13,353		)	514		(1,678		)	(14,517		)
Fair value adjustments - fair value option	(93,935		)	—		—			(93,935		)
ULAE	7,827			—		—			7,827
Total reinsurance reserves recoverable	1,461,008			33,435		583,465			2,077,908
Paid losses recoverable	137,210			1,181		103,478			241,869
Total	$	1,598,218		$	34,616	$	686,943		$	2,319,777

Reconciliation to Consolidated Balance Sheet:
Reinsurance balances recoverable on paid and unpaid losses	$	944,822		$	34,616	$	686,943		$	1,666,381
Reinsurance balances recoverable on paid and unpaid losses - fair value option	653,396			—		—			653,396
Total	$	1,598,218		$	34,616	$	686,943		$	2,319,777



	December 31, 2019
	Non-life Run-off			Atrium		StarStone			Total
Recoverable from reinsurers on unpaid:
Outstanding losses	$	972,293		$	9,011	$	328,009		$	1,309,313
IBNR	673,059			19,286		211,404			903,749
Fair value adjustments - acquired companies	(13,652		)	519		(2,122		)	(15,255		)
Fair value adjustments - fair value option	(88,086		)	—		—			(88,086		)
Total reinsurance reserves recoverable	1,543,614			28,816		537,291			2,109,721
Paid losses recoverable	181,375			1,541		87,253			270,169
Total	$	1,724,989		$	30,357	$	624,544		$	2,379,890

Reconciliation to Consolidated Balance Sheet:
Reinsurance balances recoverable on paid and unpaid losses	$	1,029,471		$	30,357	$	624,544		$	1,684,372
Reinsurance balances recoverable on paid and unpaid losses - fair value option	695,518			—		—			695,518
Total	$	1,724,989		$	30,357	$	624,544		$	2,379,890



	March 31, 2020
	Gross		Allowance for estimated uncollectible reinsurance		Net		Provisions as a % of Gross
Reinsurers rated A- or above	$	1,853,658	$	42,759	$	1,810,899	2.3	%
Reinsurers rated below A-, secured	478,752		—		478,752		—	%
Reinsurers rated below A-, unsecured	130,694		100,568		30,126		76.9	%
Total	$	2,463,104	$	143,327	$	2,319,777	5.8	%



	December 31, 2019
	Gross		Allowance for estimated uncollectible reinsurance		Net		Provisions as a % of Gross
Reinsurers rated A- or above	$	1,904,268	$	43,427	$	1,860,841	2.3	%
Reinsurers rated below A-, secured	487,608		—		487,608		—	%
Reinsurers rated below A-, unsecured	135,653		104,212		31,441		76.8	%
Total	$	2,527,529	$	147,639	$	2,379,890	5.8	%

The following table provides a summary of premiums written and earned by segment and for our other activities:



	Three Months Ended March 31,
	2020						2019
	Premiums Written			Premiums Earned			Premiums Written			Premiums Earned
Non-life Run-off
Gross	$	327		$	18,078		$	(20,877	)	$	83,966
Ceded	1,849			(2,048		)	1,699			(7,292		)
Net	$	2,176		$	16,030		$	(19,178	)	$	76,674
Atrium
Gross	$	57,837		$	47,833		$	53,985		$	43,386
Ceded	(9,139		)	(5,463		)	(7,486		)	(4,633		)
Net	$	48,698		$	42,370		$	46,499		$	38,753
StarStone
Gross	$	279,854		$	258,107		$	251,373		$	268,264
Ceded	(90,819		)	(59,947		)	(56,772		)	(55,002		)
Net	$	189,035		$	198,160		$	194,601		$	213,262
Other
Gross	$	(3,885	)	$	2,673		$	864		$	6,673
Ceded	664			664			(19		)	(75		)
Net	$	(3,221	)	$	3,337		$	845		$	6,598
Total
Gross	$	334,133		$	326,691		$	285,345		$	402,289
Ceded	(97,445		)	(66,794		)	(62,578		)	(67,002		)
Total	$	236,688		$	259,897		$	222,767		$	335,287

Goodwill and Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets and Goodwill

The following table presents a reconciliation of the beginning and ending goodwill and intangible assets during the three months ended March 31, 2020:



			Intangible assets
	Goodwill		Intangible assets with a definite life			Intangible assets with an indefinite life		Total			Total
Balance as of January 1, 2020	$	114,807	$	14,630		$	87,031	$	101,661		$	216,468
Amortization	—		(508		)	—		(508		)	(508		)
Balance as of March 31, 2020	$	114,807	$	14,122		$	87,031	$	101,153		$	215,960

Intangible Assets Amortization

The following table provides a summary of the amortization recorded on the intangible assets:



	Three Months Ended March 31,
	2020		2019
Intangible asset amortization	$	508	$	565

Schedule of Indefinite-Lived Intangible Assets

The gross carrying value, accumulated amortization and net carrying value of intangible assets by type was as follows:



	March 31, 2020							December 31, 2019
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Gross Carrying Value		Accumulated Amortization			Net Carrying Value
Intangible assets with a definite life:
Distribution channel	$	20,000	$	(8,444	)	$	11,556	$	20,000	$	(8,111	)	$	11,889
Brand	7,000		(4,434		)	2,566		7,000		(4,259		)	2,741
Total	$	27,000	$	(12,878	)	$	14,122	$	27,000	$	(12,370	)	$	14,630
Intangible assets with an indefinite life:
Lloyd’s syndicate capacity	$	37,031	$	—		$	37,031	$	37,031	$	—		$	37,031
Licenses	19,900		—			19,900		19,900		—			19,900
Management contract	30,100		—			30,100		30,100		—			30,100
Total	$	87,031	$	—		$	87,031	$	87,031	$	—		$	87,031

Schedule of Finite-Lived Intangible Assets

The gross carrying value, accumulated amortization and net carrying value of intangible assets by type was as follows:



	March 31, 2020							December 31, 2019
	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Gross Carrying Value		Accumulated Amortization			Net Carrying Value
Intangible assets with a definite life:
Distribution channel	$	20,000	$	(8,444	)	$	11,556	$	20,000	$	(8,111	)	$	11,889
Brand	7,000		(4,434		)	2,566		7,000		(4,259		)	2,741
Total	$	27,000	$	(12,878	)	$	14,122	$	27,000	$	(12,370	)	$	14,630
Intangible assets with an indefinite life:
Lloyd’s syndicate capacity	$	37,031	$	—		$	37,031	$	37,031	$	—		$	37,031
Licenses	19,900		—			19,900		19,900		—			19,900
Management contract	30,100		—			30,100		30,100		—			30,100
Total	$	87,031	$	—		$	87,031	$	87,031	$	—		$	87,031

Debt Obligations and Credit Facilities (Tables)

3 Months Ended

Mar. 31, 2020

Debt Disclosure [Abstract]

Amounts of Loans Payable Outstanding, and Accrued Interest

Our debt obligations were as follows:



Facility	Origination Date	Term	March 31, 2020		December 31, 2019
4.50% Senior Notes due 2022	March 10, 2017	5 years	$	348,794	$	348,616
4.95% Senior Notes due 2029	May 28, 2019	10 years	493,643		493,600
Total Senior Notes			842,437		842,216
EGL Revolving Credit Facility	August 16, 2018	5 years	350,000		—
2018 EGL Term Loan Facility	December 27, 2018	3 years	349,117		348,991
Total debt obligations			$	1,541,554	$	1,191,207

Interest Expense

The table below provides a summary of the total interest expense:



	Three Months Ended March 31,
	2020		2019
Interest expense on debt obligations	$	13,195	$	10,453
Amortization of debt issuance costs	220		273
Funds withheld balances and other	—		310
Total interest expense	$	13,415	$	11,036

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Name Accounting Standards Codification
-Topic 835
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-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 505
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-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Noncontrolling Interests (Tables)

3 Months Ended

Mar. 31, 2020

Noncontrolling Interest [Abstract]

Carrying Amount of Equity Attributable to Noncontrolling Interest

The following is a reconciliation of the beginning and ending carrying amount of the equity attributable to the RNCI:



	Three Months Ended
	March 31,
	2020			2019
Balance at beginning of period	$	438,791		$	458,543
Net losses attributable to RNCI	(31,959		)	(2,544		)
Accumulated other comprehensive earnings (losses) attributable to RNCI	(4,170		)	85
Change in redemption value of RNCI	(10,150		)	262
Cumulative effect of change in accounting principle attributable to RNCI ⁽¹⁾	261			—
Balance at end of period	$	392,773		$	456,346

⁽¹⁾ The Company adopted ASU 2016-13 and the related amendments on January 1, 2020. Refer to Note 1 - "Significant Accounting Policies" for further details.

Share Capital (Tables)

3 Months Ended

Mar. 31, 2020

Equity [Abstract]

Dividends Declared

The following table details the dividends that have been declared and paid on our Series D and E Preferred Shares for the period from January 1, 2020 to May 7, 2020:



				Dividend per:
Preferred Share Series	Date Declared	Record Date	Date Paid or Payable	Preferred Share		Depositary Share		Total dividends paid in the three months ended March 31, 2020
				(in U.S. dollars)				(in thousands of U.S. dollars)
Series D	February 4, 2020	February 15, 2020	March 2, 2020	$	437.50	$	0.43750	$	7,000
Series E	February 4, 2020	February 15, 2020	March 2, 2020	$	437.50	$	0.43750	1,925
Series D	May 5, 2020	May 15, 2020	June 1, 2020	$	437.50	$	0.43750	—
Series E	May 5, 2020	May 15, 2020	June 1, 2020	$	437.50	$	0.43750	—
								$	8,925

Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2020

Earnings Per Share [Abstract]

Comparison of Basic and Diluted Earnings per Share

The following table sets forth the computation of basic and diluted net earnings per ordinary share:



	Three Months Ended
	March 31,
	2020			2019
Numerator:
Net earnings (losses) attributable to Enstar ordinary shareholders:	$	(516,821	)	$	358,751
Denominator:
Weighted-average ordinary shares outstanding — basic ⁽¹⁾	21,549,844			21,463,499
Effect of dilutive securities:
Share-based compensation plans ⁽²⁾	164,435			122,980
Warrants	65,627			59,383
Weighted-average ordinary shares outstanding — diluted	21,779,906			21,645,862

Earnings (losses) per ordinary share attributable to Enstar:
Basic net earnings (losses) per ordinary share	$	(23.98	)	$	16.71
Diluted net earnings (losses) per ordinary share ⁽³⁾	$	(23.98	)	$	16.57

⁽¹⁾Weighted-average ordinary shares for basic earnings per share includes ordinary shares (voting and non-voting) but excludes ordinary shares held in the EB Trust in respect of JSOP awards.

Share-Based Compensation and Pensions (Tables)

3 Months Ended

Mar. 31, 2020

Retirement Benefits [Abstract]

Schedule of Compensation Cost for Share-based Compensation Plans

The table below provides a summary of the compensation costs for all of our share-based compensation plans:



	Three Months Ended March 31,
	2020			2019
Share-based compensation plans:
Restricted shares and restricted share units	$	1,599		$	1,843
Performance share units	(667		)	1,325
Cash-settled stock appreciation rights	(3,159		)	56
Joint share ownership plan expense	872			—
Other share-based compensation plans:
Northshore incentive plan	472			1,046
StarStone incentive plan	(223		)	—
Deferred compensation and ordinary share plan for non-employee directors	866			827
Employee share purchase plan	104			103
Total share-based compensation	$	(136	)	$	5,200

Related Party Transactions (Tables)

3 Months Ended

Mar. 31, 2020

Schedule of Related Party Transactions

The RNCI on our balance sheet relating to these Trident co-investment transactions was as follows:



	March 31, 2020		December 31, 2019
Redeemable Noncontrolling Interest	$	376,399	$	420,499

The following table presents the amounts included in our consolidated balance sheet related to our related party transactions with Stone Point and its affiliated entities:



	March 31, 2020		December 31, 2019
Short-term investments, AFS, at fair value	$	1,134	$	1,431
Fixed maturities, trading, at fair value	208,255		269,131
Fixed maturities, AFS, at fair value	199,563		160,303
Equities, at fair value	91,820		121,794
Other investments, at fair value:
Hedge funds	16,501		18,993
Fixed income funds	310,397		381,449
Private equity funds	32,241		34,858
CLO equities	31,842		32,560
CLO equity funds	66,938		87,509
Private Debt	16,528		16,312
Real estate fund	21,644		18,106
Cash and cash equivalents	55,391		54,080
Other assets	346		10
Other liabilities	457		4,710

The following table presents the amounts included in net earnings related to our related party transactions with Stone Point and its affiliated entities:



	Three Months Ended March 31,
	2020			2019
Net investment income	$	4,084		$	1,075
Net realized and unrealized (losses) gains	(102,516		)	20,133
Total net (losses) earnings	$	(98,432	)	$	21,208

Our consolidated balance sheet included the following balances related to transactions with Hillhouse Capital and AnglePoint:



	March 31, 2020			December 31, 2019
Investments in funds managed by AnglePoint, held by Enhanzed Re	$	380,681		$	327,799
Our ownership of equity method investments	47.4		%	47.4		%
Our share of funds managed by AnglePoint, held by Enhanzed Re	$	180,443		$	155,377

Investment in other funds managed by Hillhouse Capital and AnglePoint:
InRe Fund	$	869,275		$	918,633
Other funds	213,123			232,968
	$	1,082,398		$	1,151,601

Our investment in the common and preferred shares of Monument, carried in equity method investments on our consolidated balance sheet was as follows:



	March 31, 2020		December 31, 2019
Investment in Monument	$	57,737	$	60,598

Our investment in the common shares of Clear Spring, carried in equity method investments on our consolidated balance sheet, was as follows:



	March 31, 2020		December 31, 2019
Investment in Clear Spring	$	10,952	$	10,645

Our consolidated balance sheet included the following balances between us and Clear Spring:



	March 31, 2020		December 31, 2019
Balances under StarStone ceding quota share:
Reinsurance balances recoverable	$	23,566	$	22,812
Prepaid insurance premiums	12		51
Ceded payable	4,189		3,616
Ceded acquisition costs	—		21

Balances under assuming quota share:
Losses and LAE	5,307		6,135
Unearned reinsurance premiums	3		13
Funds held	8,303		8,611

Our consolidated statement of earnings included the following amounts between us and Clear Spring:



	Three Months Ended
	March 31,
	2020			2019

Transactions under StarStone ceding quota share:
Ceded premium earned	$	(681	)	$	(5,485	)
Ceded incurred losses and LAE	754			3,859
Ceded acquisition costs	72			54

Transactions under assuming quota share:
Premium earned	170			1,371
Net incurred losses and LAE	372			(965		)
Acquisition costs	(13		)	(14		)

Total net earnings (loss)	$	674		$	(1,180	)

Our indirect investment in the shares of AmTrust, carried in equities on our consolidated balance sheet was as follows:



	March 31, 2020		December 31, 2019
Investment in AmTrust	$	241,328	$	240,115

Our indirect investment in the shares of Citco, carried in equity method investments on our consolidated balance sheet, was as follows:



	March 31, 2020		December 31, 2019
Investment in Citco	$	51,504	$	51,742

Our investment in the common shares of Enhanzed Re, carried in equity method investments on our consolidated balance sheet was as follows:



	March 31, 2020		December 31, 2019
Investment in Enhanzed Re	$	197,206	$	182,856

Our consolidated balance sheet included the following balances between us and Enhanzed Re:



	March 31, 2020		December 31, 2019
Balances under ceding quota share:
Insurance balances payables	$	1,519	$	1,443
Reinsurance balances recoverable	58,022		59,601
Funds held	48,383		50,089

Other assets	400		1,033

Our consolidated statement of earnings included the following amounts between us and Enhanzed Re:



	Three Months Ended March 31, 2020
	2020		2019
Amounts under ceding quota share:
Acquisition costs	23		—

Other income	291		86

Total net earnings	$	314	$	86

Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

Lease, Cost and Other Lease Information

The table below provides the lease cost and other information relating to our operating leases:



	Three Months Ended March 31,
	2020			2019
Lease cost
Operating lease cost	$	3,322		$	3,487
Short-term lease cost⁽¹⁾	58			—
Total lease cost	3,380			3,487
Sub-lease income⁽²⁾	(138		)	(131		)
Total net lease cost	$	3,242		$	3,356

Other information
Operating Cash paid for amounts included in the measurement of lease liabilities	$	3,183		$	3,024
Non-cash activity: right-of-use assets relating to leases	72			51,609
Weighted-average remaining lease term	6.2 years			6.6 years
Weighted-average discount rate	6.3		%	6.2		%

⁽¹⁾ Leases with an initial lease term of twelve months or less are not recognized within our consolidated balance sheets.

Assets and Liabilities, Lessee

The table below provides a summary of the operating leases recorded on our consolidated balance sheets:



	Balance sheet classification	March 31, 2020		December 31, 2019
Right-of-use assets	Other assets	$	39,300	$	46,747
Current lease liabilities	Other liabilities	10,467		11,403
Non-current lease liabilities	Other liabilities	31,319		34,785

Lessee, Operating Lease, Liability, Maturity

The table below provides a summary of the contractual maturities of our operating lease liabilities:



	March 31, 2020
2020	$	9,938
2021	9,578
2022	7,893
2023	6,873
2024	5,147
2025 and beyond	12,205
Total lease payments ⁽¹⁾	51,634
Less: Imputed interest	(9,848		)
Present value of lease liabilities	$	41,786

⁽¹⁾ Amount excludes short-term leases.

Segment Information (Tables)

3 Months Ended

Mar. 31, 2020

Segment Reporting [Abstract]

Summary of Operations by Segment

The following tables set forth selected and unaudited condensed consolidated statement of earnings results by segment and for our other activities:



	Three Months Ended March 31, 2020
	Non-life Run-off			Atrium			StarStone			Other			Total
Gross premiums written	$	327		$	57,837		$	279,854		$	(3,885	)	$	334,133

Net premiums written	$	2,176		$	48,698		$	189,035		$	(3,221	)	$	236,688

Net premiums earned	$	16,030		$	42,370		$	198,160		$	3,337		$	259,897
Net incurred losses and LAE	62,034			(28,416		)	(139,030		)	(2,482		)	(107,894		)
Acquisition costs	(6,907		)	(14,384		)	(45,212		)	(83		)	(66,586		)
Operating expenses	(48,210		)	(2,877		)	(34,552		)	—			(85,639		)
Underwriting income (loss)	22,947			(3,307		)	(20,634		)	772			(222		)
Net investment income (loss)	67,451			1,525			11,352			(2,488		)	77,840
Net realized and unrealized losses	(574,682		)	(5,708		)	(54,086		)	—			(634,476		)
Fees and commission income	4,985			2,543			—			—			7,528
Other income (expense)	22,295			35			85			(1,971		)	20,444
Corporate expenses	(8,120		)	(3,138		)	(574		)	(16,040		)	(27,872		)
Interest income (expense)	(15,899		)	—			(447		)	2,931			(13,415		)
Net foreign exchange gains (losses)	14,653			(2,133		)	(590		)	—			11,930
LOSS BEFORE INCOME TAXES	(466,370		)	(10,183		)	(64,894		)	(16,796		)	(558,243		)
Income tax benefit	2,807			753			1,615			—			5,175
Earnings from equity method investments	12,450			—			—			—			12,450
NET LOSS	(451,113		)	(9,430		)	(63,279		)	(16,796		)	(540,618		)
Net loss attributable to noncontrolling interest	2,087			3,868			26,767			—			32,722
NET LOSS ATTRIBUTABLE TO ENSTAR	(449,026		)	(5,562		)	(36,512		)	(16,796		)	(507,896		)
Dividends on preferred shares	—			—			—			(8,925		)	(8,925		)
NET LOSS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$	(449,026	)	$	(5,562	)	$	(36,512	)	$	(25,721	)	$	(516,821	)

Underwriting ratios:
Loss ratio				67.1		%	70.2		%
Acquisition expense ratio				33.9		%	22.8		%
Operating expense ratio				6.8		%	17.4		%
Combined ratio				107.8		%	110.4		%



	Three Months Ended March 31, 2019
	Non-life Run-off			Atrium			StarStone			Other			Total
Gross premiums written	$	(20,877	)	$	53,985		$	251,373		$	864		$	285,345

Net premiums written	$	(19,178	)	$	46,499		$	194,601		$	845		$	222,767

Net premiums earned	$	76,674		$	38,753		$	213,262		$	6,598		$	335,287
Net incurred losses and LAE	(95,182		)	(17,214		)	(195,052		)	(4,956		)	(312,404		)
Life and Annuity Policy Benefits	—			—			—			(96		)	(96		)
Acquisition costs	(28,155		)	(13,742		)	(51,659		)	(232		)	(93,788		)
Operating expenses	(43,992		)	(3,033		)	(35,994		)	—			(83,019		)
Underwriting income (loss)	(90,655		)	4,764			(69,443		)	1,314			(154,020		)
Net investment income (loss)	66,728			1,711			11,942			(1,685		)	78,696
Net realized and unrealized gains	436,186			2,913			20,658			1,034			460,791
Fees and commission income	4,832			1,849			—			—			6,681
Other income	5,504			36			60			212			5,812
Corporate expenses	(16,570		)	(3,788		)	—			(8,697		)	(29,055		)
Interest income (expense)	(12,116		)	—			(475		)	1,555			(11,036		)
Net foreign exchange gains (losses)	3,618			825			(594		)	1			3,850
EARNINGS (LOSS) BEFORE INCOME TAXES	397,527			8,310			(37,852		)	(6,266		)	361,719
Income tax expense	(2,720		)	(685		)	(1,259		)	(85		)	(4,749		)
Earnings from equity method investments	8,584			—			188			—			8,772
NET EARNINGS (LOSS)	403,391			7,625			(38,923		)	(6,351		)	365,742
Net loss (earnings) attributable to noncontrolling interest	(2,646		)	(3,128		)	7,922			—			2,148
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR	400,745			4,497			(31,001		)	(6,351		)	367,890
Dividend on preferred shares	—			—			—			(9,139		)	(9,139		)
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$	400,745		$	4,497		$	(31,001	)	$	(15,490	)	$	358,751

Underwriting ratios:
Loss ratio				44.4		%	91.5		%
Acquisition expense ratio				35.5		%	24.2		%
Operating expense ratio				7.8		%	16.9		%
Combined ratio				87.7		%	132.6		%

Summary of Company's Assets by Segment



	March 31, 2020			December 31, 2019
Assets by Segment:
Non-life Run-off	$	15,438,588		$	15,775,409
Atrium	590,805			580,405
StarStone	3,627,036			3,522,353
Other	(524,920		)	(514,852		)
Total assets	$	19,131,509		$	19,363,315

Significant Accounting Policies (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to retained earnings	$ 2,375,073		$ 2,887,892
Reinsurance recoverable, allowance for credit loss	143,327		147,639
Allowance for credit losses	$ 16,271		0
Cumulative effect of change in accounting principle
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to retained earnings		$ (6,100)
Financial instruments, allowance for credit loss		3,000
Reinsurance recoverable, allowance for credit loss		200	(195)
Allowance for credit losses		$ 3,100	$ 3,059

Significant New Business (Details) $ in Thousands, $ in Millions		1 Months Ended	3 Months Ended
	Mar. 31, 2020 USD ($)	Apr. 30, 2020 USD ($)	Sep. 30, 2020 AUD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)
Guarantor Obligations [Line Items]
Assumed business						$ 471,150	$ 620,418
Pacific Valley Insurance Company
Guarantor Obligations [Line Items]
Reinsurance premium consideration	$ 465,000					$ 465,000
Scenario, Forecast \| Aspen
Guarantor Obligations [Line Items]
Reinsurance premium consideration					$ 770,000
Assumed business					770,000
Additional assumed business					250,000
Scenario, Forecast \| AXA Group
Guarantor Obligations [Line Items]
Net loss reserves					225,000
Scenario, Forecast \| Munich Re
Guarantor Obligations [Line Items]
Net loss reserves			$ 228.2	$ 139,300
Subsequent Event \| Pacific Valley Insurance Company
Guarantor Obligations [Line Items]
Retrocession coverage		$ 816,000
Minimum \| Scenario, Forecast \| Aspen
Guarantor Obligations [Line Items]
Assumed business					3,800,000
Additional assumed business					$ 4,800,000

Investments - Asset Types - Fixed Maturity Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	$ 2,279,073	$ 2,041,724
Total fair value	9,023,770	9,612,888
U.S. government and agency
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	238,219	410,312
Total fair value	519,933	736,043
U.K. government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	32,910	15,349
Total fair value	100,005	161,772
Other government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	83,341	85,147
Total fair value	604,014	702,857
Corporate
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	1,332,566	1,081,171
Total fair value	5,538,691	5,697,067
Municipal
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	17,046	15,872
Total fair value	164,830	167,882
Residential mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	155,027	127,219
Total fair value	467,918	471,836
Commercial mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	130,878	98,557
Total fair value	873,504	900,029
Asset-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	289,086	208,097
Total fair value	754,875	775,402
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	363,600	356,900
Senior Secured Debt Securities
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	8,800	31,400
Short-term Investments
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	18,249	51,490
Debt securities, fair value	138,900	128,335
Short-term Investments \| U.S. government and agency
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	766	0
Debt securities, fair value	34,582	111,583
Short-term Investments \| U.K. government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	3,675	24,411
Debt securities, fair value	3,337	1,069
Short-term Investments \| Other government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	11,022	21,958
Debt securities, fair value	334	387
Short-term Investments \| Corporate
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	2,368	5,121
Debt securities, fair value	99,277	13,915
Short-term Investments \| Municipal
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	418	0
Debt securities, fair value	1,370	1,381
Short-term Investments \| Residential mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	0	0
Debt securities, fair value	0	0
Short-term Investments \| Commercial mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	0	0
Debt securities, fair value	0	0
Short-term Investments \| Asset-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	0	0
Debt securities, fair value	0	0
Fixed maturity investments
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	5,644,819	6,346,329
Debt securities, fair value	2,140,173	1,913,389
Fixed maturity investments \| U.S. government and agency
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	186,693	219,194
Debt securities, fair value	203,637	298,729
Fixed maturity investments \| U.K. government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	63,420	122,012
Debt securities, fair value	29,573	14,280
Fixed maturity investments \| Other government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	490,111	575,018
Debt securities, fair value	83,007	84,760
Fixed maturity investments \| Corporate
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	3,649,143	4,007,386
Debt securities, fair value	1,233,289	1,067,256
Fixed maturity investments \| Municipal
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	98,341	102,554
Debt securities, fair value	15,676	14,491
Fixed maturity investments \| Residential mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	229,723	258,412
Debt securities, fair value	155,027	127,219
Fixed maturity investments \| Commercial mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	523,207	571,129
Debt securities, fair value	130,878	98,557
Fixed maturity investments \| Asset-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	404,181	490,624
Debt securities, fair value	289,086	208,097
Funds held - directly managed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	1,081,629	1,173,345
Funds held - directly managed \| U.S. government and agency
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	94,255	106,537
Funds held - directly managed \| U.K. government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	0	0
Funds held - directly managed \| Other government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	19,540	20,734
Funds held - directly managed \| Corporate
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	554,614	603,389
Funds held - directly managed \| Municipal
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	49,025	49,456
Funds held - directly managed \| Residential mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	83,168	86,205
Funds held - directly managed \| Commercial mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	219,419	230,343
Funds held - directly managed \| Asset-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	$ 61,608	$ 76,681

Investments - Contractual Maturities (Details) - Short-Term Investments and Fixed Maturities $ in Thousands	Mar. 31, 2020 USD ($)
Amortized Cost
One year or less	$ 502,300
More than one year through two years	754,996
More than two years through five years	2,209,294
More than five years through ten years	2,080,140
More than ten years	1,439,507
Trading securities, amortized cost	9,177,658
Fair Value
One year or less	497,009
More than one year through two years	747,837
More than two years through five years	2,156,740
More than five years through ten years	2,049,319
More than ten years	1,476,568
Trading securities, debt	$ 9,023,770
% of Total Fair Value
One year or less	5.50%
More than one year through two years	8.30%
More than two years through five years	23.90%
More than five years through ten years	22.70%
More than ten years	16.30%
Trading securities, percentage of fair value	100.00%
Residential mortgage-backed
Amortized Cost
Securities without single maturity date	$ 466,964
Fair Value
Securities without single maturity date	$ 467,918
% of Total Fair Value
Securities without single maturity date	5.20%
Commercial mortgage-backed
Amortized Cost
Securities without single maturity date	$ 894,859
Fair Value
Securities without single maturity date	$ 873,504
% of Total Fair Value
Securities without single maturity date	9.70%
Asset-backed
Amortized Cost
Securities without single maturity date	$ 829,598
Fair Value
Securities without single maturity date	$ 754,875
% of Total Fair Value
Securities without single maturity date	8.40%

Investments - Available-for-sale Portfolios - Unrealized Gains and Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,342,582	$ 2,042,454
Gross Unrealized Gains	19,011	5,971
Gross Unrealized Losses Non-OTTI	(66,249)	(6,701)
Allowance for credit losses	(16,271)	0
Debt securities, fair value	2,279,073	2,041,724
U.S. government and agency
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	230,450	410,842
Gross Unrealized Gains	7,783	77
Gross Unrealized Losses Non-OTTI	(14)	(607)
Allowance for credit losses	0
Debt securities, fair value	238,219	410,312
U.K. government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	33,953	15,067
Gross Unrealized Gains	0	282
Gross Unrealized Losses Non-OTTI	(1,043)	0
Allowance for credit losses	0
Debt securities, fair value	32,910	15,349
Other government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	84,302	84,116
Gross Unrealized Gains	1,416	1,119
Gross Unrealized Losses Non-OTTI	(2,377)	(88)
Allowance for credit losses	0	0
Debt securities, fair value	83,341	85,147
Corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,374,000	1,081,713
Gross Unrealized Gains	5,680	4,026
Gross Unrealized Losses Non-OTTI	(30,844)	(4,568)
Allowance for credit losses	(16,270)	0
Debt securities, fair value	1,332,566	1,081,171
Municipal
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	16,799	15,963
Gross Unrealized Gains	250	20
Gross Unrealized Losses Non-OTTI	(3)	(111)
Allowance for credit losses	0
Debt securities, fair value	17,046	15,872
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	153,268	127,704
Gross Unrealized Gains	2,943	240
Gross Unrealized Losses Non-OTTI	(1,184)	(725)
Allowance for credit losses	0
Debt securities, fair value	155,027	127,219
Commercial mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	137,641	98,928
Gross Unrealized Gains	744	38
Gross Unrealized Losses Non-OTTI	(7,506)	(409)
Allowance for credit losses	(1)	0
Debt securities, fair value	130,878	98,557
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	312,169	208,121
Gross Unrealized Gains	195	169
Gross Unrealized Losses Non-OTTI	(23,278)	(193)
Allowance for credit losses	0
Debt securities, fair value	$ 289,086	$ 208,097

Investments - Gross Unrealized Losses (Details) $ in Thousands	Mar. 31, 2020 USD ($) Security	Dec. 31, 2019 USD ($) Security
Fair Value
12 Months or Greater	$ 3,382	$ 3,962
Less Than 12 Months	999,201	1,008,869
Total	1,002,583	1,012,831
Gross Unrealized Losses
12 Months or Greater	(542)	(329)
Less Than 12 Months	(45,536)	(6,372)
Total	$ (46,078)	$ (6,701)
Number of securities classified as available-for-sale in an unrealized loss position \| Security	896	563
Number of securities classified as available-for-sale in an unrealized loss position for twelve months or longer \| Security	9	12
U.S. government and agency
Fair Value
12 Months or Greater	$ 0	$ 0
Less Than 12 Months	1,399	222,643
Total	1,399	222,643
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(14)	(607)
Total	(14)	(607)
U.K. government
Fair Value
12 Months or Greater		0
Less Than 12 Months		32,909
Total		32,909
Gross Unrealized Losses
12 Months or Greater		0
Less Than 12 Months		(1,043)
Total		(1,043)
Other government
Fair Value
12 Months or Greater	992	1,080
Less Than 12 Months	40,315	37,796
Total	41,307	38,876
Gross Unrealized Losses
12 Months or Greater	(110)	(23)
Less Than 12 Months	(2,267)	(65)
Total	(2,377)	(88)
Corporate
Fair Value
12 Months or Greater	2,390	2,754
Less Than 12 Months	532,456	461,772
Total	534,846	464,526
Gross Unrealized Losses
12 Months or Greater	(432)	(306)
Less Than 12 Months	(10,287)	(4,262)
Total	(10,719)	(4,568)
Municipal
Fair Value
12 Months or Greater	0	128
Less Than 12 Months	473	12,046
Total	473	12,174
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(3)	(111)
Total	(3)	(111)
Residential mortgage-backed
Fair Value
12 Months or Greater	0	0
Less Than 12 Months	33,738	65,992
Total	33,738	65,992
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(1,184)	(725)
Total	(1,184)	(725)
Commercial mortgage-backed
Fair Value
12 Months or Greater	0	0
Less Than 12 Months	93,706	79,606
Total	93,706	79,606
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(7,460)	(409)
Total	(7,460)	(409)
Asset-backed
Fair Value
12 Months or Greater	0	0
Less Than 12 Months	264,205	129,014
Total	264,205	129,014
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(23,278)	(193)
Total	$ (23,278)	$ (193)

Investments - Allowance for Credit Losses (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	$ 0
Allowances for credit losses on securities for which credit losses were not previously recorded	(13,681)
Reductions for securities sold during the period	369
Reductions in the allowance for credit losses on securities we either intend to sell or more likely than not, we will be required to sell before the recovery of their amortized cost basis	100
Allowance for credit loss, end of period	(16,271)
Other government
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	0
Allowances for credit losses on securities for which credit losses were not previously recorded	0
Reductions for securities sold during the period	0
Reductions in the allowance for credit losses on securities we either intend to sell or more likely than not, we will be required to sell before the recovery of their amortized cost basis	22
Allowance for credit loss, end of period	0
Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	0
Allowances for credit losses on securities for which credit losses were not previously recorded	(13,681)
Reductions for securities sold during the period	369
Reductions in the allowance for credit losses on securities we either intend to sell or more likely than not, we will be required to sell before the recovery of their amortized cost basis	29
Allowance for credit loss, end of period	(16,270)
Commercial mortgage-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	0
Allowances for credit losses on securities for which credit losses were not previously recorded	0
Reductions for securities sold during the period	0
Reductions in the allowance for credit losses on securities we either intend to sell or more likely than not, we will be required to sell before the recovery of their amortized cost basis	49
Allowance for credit loss, end of period	(1)
Cumulative effect of change in accounting principle
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	(3,059)
Cumulative effect of change in accounting principle \| Other government
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	(22)
Cumulative effect of change in accounting principle \| Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	(2,987)
Cumulative effect of change in accounting principle \| Commercial mortgage-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	$ (50)

Investments - Other Than Temporary Impairment (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Other than temporary impairment losses, available-for-sale securities	$ 0
Available-for-sale Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Credit losses		$ 0

Investments - Equities - Equity Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Equities, at fair value	$ 641,850	$ 729,721
Publicly traded equity investments in common and preferred stocks
Debt and Equity Securities, FV-NI [Line Items]
Equities, at fair value	240,932	327,875
Exchange-traded funds
Debt and Equity Securities, FV-NI [Line Items]
Equities, at fair value	130,906	133,047
Privately held equity investments in common and preferred stocks
Debt and Equity Securities, FV-NI [Line Items]
Equities, at fair value	270,012	268,799
AmTrust Financial Services, Inc.
Debt and Equity Securities, FV-NI [Line Items]
Fair value of indirect investment	$ 241,300	$ 240,100

Investments - Other Investments, at Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Other Investments [Line Items]
Other investments, at fair value	$ 2,326,984		$ 2,524,420
Valuation lag period	3 months
Additional subscriptions	$ (160,814)	$ (225,961)
Hedge funds
Other Investments [Line Items]
Other investments, at fair value	1,055,448		1,121,904
Fixed income funds
Other Investments [Line Items]
Other investments, at fair value	463,717		481,039
Equity funds
Other Investments [Line Items]
Other investments, at fair value	320,046		410,149
Private equities and private equity funds
Other Investments [Line Items]
Other investments, at fair value	309,219		329,885
Unfunded commitments	773,600
CLO equities
Other Investments [Line Items]
Other investments, at fair value	83,740		87,555
CLO equity funds
Other Investments [Line Items]
Other investments, at fair value	66,938		87,509
Private credit funds
Other Investments [Line Items]
Other investments, at fair value	20,473		0
Other
Other Investments [Line Items]
Other investments, at fair value	7,403		$ 6,379
Other investments
Other Investments [Line Items]
Unrealized gain on investment	(258,132)	$ 204,709
Additional subscriptions	$ (75,100)

Investments - Equity Method Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Investment	$ 266,823	$ 266,823
Ownership %	47.40%	47.40%
Equity method investments	$ 337,474	$ 326,277
Enhanzed Re
Schedule of Equity Method Investments [Line Items]
Investment	$ 154,050	$ 154,050
Ownership %	47.40%	47.40%
Equity method investments	$ 197,206	$ 182,856
Citco
Schedule of Equity Method Investments [Line Items]
Investment	$ 50,000	$ 50,000
Ownership %	31.90%	31.90%
Equity method investments	$ 51,504	$ 51,742
Monument
Schedule of Equity Method Investments [Line Items]
Investment	$ 26,600	$ 26,600
Ownership %	26.60%	26.60%
Equity method investments	$ 57,737	$ 60,598
Clear Spring
Schedule of Equity Method Investments [Line Items]
Investment	$ 11,210	$ 11,210
Ownership %	20.00%	20.00%
Equity method investments	$ 10,952	$ 10,645
Other
Schedule of Equity Method Investments [Line Items]
Investment	$ 24,963	$ 24,963
Ownership %	30.00%	30.00%
Equity method investments	$ 20,075	$ 20,436
Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Unfunded commitments	$ 110,500

Investments - Funds Held Directly Managed Components (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Funds Held, Directly Managed [Line Items]
Funds held - directly managed	$ 1,134,921	$ 1,187,552
Funds held - directly managed
Schedule of Funds Held, Directly Managed [Line Items]
Debt securities, trading	1,081,629	1,173,345
Cash and cash equivalents	51,209	10,296
Funds held - directly managed, other assets	2,083	3,911
Funds held - directly managed	$ 1,134,921	$ 1,187,552

Investments - Funds Held Directly Managed - Fixed Maturity Components (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Funds held - Directly Managed - Fair Value Option
Schedule of Funds Held, Directly Managed [Line Items]
Fixed maturity investments, at amortized cost	$ 164,425	$ 185,859
Net unrealized gains (losses):
Change in fair value - fair value option accounting	2,754	5,438
Change in fair value - embedded derivative accounting		0
Debt securities, trading	167,179	191,297
Funds held - Directly Managed - Variable Return
Schedule of Funds Held, Directly Managed [Line Items]
Fixed maturity investments, at amortized cost	895,214	940,194
Net unrealized gains (losses):
Change in fair value - fair value option accounting		0
Change in fair value - embedded derivative accounting	19,236	41,854
Debt securities, trading	914,450	982,048
Funds held - directly managed
Schedule of Funds Held, Directly Managed [Line Items]
Fixed maturity investments, at amortized cost	1,059,639	1,126,053
Net unrealized gains (losses):
Change in fair value - fair value option accounting	2,754	5,438
Change in fair value - embedded derivative accounting	19,236	41,854
Debt securities, trading	$ 1,081,629	$ 1,173,345

Investments - Funds Held Directly Managed Narrative (Details) - USD ($) $ in Thousands		3 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Funds held by reinsured companies	$ 827,382	$ 827,382	$ 408,735
Pacific Valley Insurance Company
Business Acquisition [Line Items]
Reinsurance premium consideration	$ 465,000	$ 465,000

Investments - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Net Investment Income [Line Items]
Gross investment income	$ 82,544		$ 82,972
Investment expenses	(4,704)		(4,276)
Net investment income	77,840	$ 78,696	78,696
Fixed maturity investments
Net Investment Income [Line Items]
Gross investment income	57,195		58,070
Short-term investments and cash and cash equivalents
Net Investment Income [Line Items]
Gross investment income	2,794		3,860
Funds held
Net Investment Income [Line Items]
Gross investment income	271		5,798
Funds held - directly managed
Net Investment Income [Line Items]
Gross investment income	8,816		9,750
Investment income from fixed maturities and cash and cash equivalents
Net Investment Income [Line Items]
Gross investment income	69,076		77,478
Equity securities
Net Investment Income [Line Items]
Gross investment income	5,963		3,380
Other investments
Net Investment Income [Line Items]
Gross investment income	7,505		2,114
Investment income from equities and other investments
Net Investment Income [Line Items]
Gross investment income	$ 13,468		$ 5,494

Investments - Net Realized and Unrealized Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net realized gains (losses) on sale:
Total net realized gains on sale	$ 1,918	$ 270
Net unrealized gains (losses):
Total net unrealized gains	(636,394)	460,521
Net realized and unrealized gains	(634,476)	460,791
Sales of available-for-sale securities	388,800	1,200
Fixed maturity securities
Net realized gains (losses) on sale:
Gross realized gains on fixed maturity securities, available-for-sale	1,814	4
Gross realized losses on fixed maturity securities, available-for-sale	(2,026)	(65)
Credit loss on fixed maturity securities, AFS	(13,212)	0
Net realized gains (losses) on fixed maturity securities	15,837	(611)
Net unrealized gains (losses):
Fixed maturity securities, trading	(261,008)	209,467
Funds held - directly managed
Net realized gains (losses) on sale:
Net realized gains (losses) on fixed maturity securities	512	(1,606)
Net unrealized gains (losses):
Fixed maturity securities, trading	(25,302)	38,962
Equity securities
Net realized gains (losses) on sale:
Net realized gains (losses) on equity investments	(1,007)	2,548
Net unrealized gains (losses):
Equity investments	(91,952)	7,383
Other Investments
Net unrealized gains (losses):
Change in fair value of other investments	$ (258,132)	$ 204,709

Investments - Restricted Assets (Details) $ in Thousands	3 Months Ended
Investments - Restricted Assets (Details) $ in Thousands	Mar. 31, 2020 USD ($) Segment	Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)
Line of Credit Facility [Line Items]
Restricted cash and cash equivalents	$ 345,097	$ 352,692	$ 427,601
Collateral in trust for third party agreements	3,664,247	4,104,093
Assets on deposit with regulatory authorities	226,477	445,626
Funds at Lloyd's	717,970	639,316
Restricted assets, total	$ 4,733,199	5,322,273
Number of syndicates \| Segment	3
Asset Pledged as Collateral
Line of Credit Facility [Line Items]
Collateral for secured letter of credit facilities	$ 124,505	$ 133,238

Derivative and Hedging Instruments - Foreign Currency Hedging of Net Investments (Details) - Foreign exchange forward - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Derivatives qualifying as hedges
Derivative [Line Items]
Gross Notional Amount	$ 456,858		$ 495,291
Assets	17,655		642
Liabilities	943		11,452
Net gains on qualifying derivative hedges	31,918	$ 1,528
Derivatives qualifying as hedges \| AUD
Derivative [Line Items]
Gross Notional Amount	56,149		64,620
Assets	4,269		52
Liabilities	0		2,033
Net gains on qualifying derivative hedges	8,471	(327)
Derivatives qualifying as hedges \| EUR
Derivative [Line Items]
Gross Notional Amount	103,127		112,284
Assets	194		246
Liabilities	943		1,635
Net gains on qualifying derivative hedges	2,635	1,855
Derivatives qualifying as hedges \| GBP
Derivative [Line Items]
Gross Notional Amount	297,582		318,387
Assets	13,192		344
Liabilities	0		7,784
Net gains on qualifying derivative hedges	20,812	0
Derivatives not qualifying as hedges
Derivative [Line Items]
Gross Notional Amount	159,944		153,563
Assets	7,652		1,369
Liabilities	2,994		4,106
Gains (Losses) on non-qualifying-hedges included in net earnings	9,281	(3,618)
Derivatives not qualifying as hedges \| AUD
Derivative [Line Items]
Gross Notional Amount	32,103		913
Assets	3,088		839
Liabilities	608		892
Gains (Losses) on non-qualifying-hedges included in net earnings	2,533	(765)
Derivatives not qualifying as hedges \| EUR
Derivative [Line Items]
Gross Notional Amount	52,660		74,444
Assets	173		507
Liabilities	1,672		1,440
Gains (Losses) on non-qualifying-hedges included in net earnings	1,176	1,205
Derivatives not qualifying as hedges \| GBP
Derivative [Line Items]
Gross Notional Amount	24,427		11,940
Assets	972		13
Liabilities	713		292
Gains (Losses) on non-qualifying-hedges included in net earnings	576	(4,059)
Derivatives not qualifying as hedges \| CAD
Derivative [Line Items]
Gross Notional Amount	50,754		66,266
Assets	3,419		10
Liabilities	1		$ 1,482
Gains (Losses) on non-qualifying-hedges included in net earnings	$ 4,996	$ 1

Derivative and Hedging Instruments - Investments in Call Options on Equities (Details) - Derivatives not qualifying as hedges - Call options on equity - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Unrealized gain (loss) on equity securities	$ (0.1)	$ (0.2)
Cost				$ 10.0
Fair value of derivatives			$ 0.1

Derivative and Hedging Instruments - Other Derivatives (Details) - Interest Rate Swap $ in Millions, $ in Millions	3 Months Ended	15 Months Ended
	Mar. 31, 2020 USD ($)	Apr. 07, 2020 USD ($)	Dec. 31, 2019 USD ($)	Oct. 31, 2019 AUD ($)
Derivative [Line Items]
Notional amount of derivative				$ 120.0
Unrealized loss in net earnings	$ (0.8)
Carrying Value
Derivative [Line Items]
Liabilities	$ 0.5		$ 0.3
Subsequent Event
Derivative [Line Items]
Gain on derivative		$ 0.5

Reinsurance Balances Recoverable on Paid and Unpaid Losses - Total Reinsurance Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Effects of Reinsurance [Line Items]
Outstanding losses	$ 1,288,022	$ 1,309,313
IBNR	890,511	903,749
Fair value adjustments - acquired companies	(14,517)	(15,255)
Fair value adjustments - fair value option	(93,935)	(88,086)
ULAE	7,827
Total reinsurance reserves recoverable	2,077,908	2,109,721	$ 2,077,923	$ 1,867,841
Paid losses recoverable	241,869	270,169
Net	2,319,777	2,379,890
Reinsurance balances recoverable on paid and unpaid losses	1,666,381	1,684,372
Reinsurance balances recoverable on paid and unpaid losses - fair value option	653,396	695,518
Non-life Run-off
Effects of Reinsurance [Line Items]
Outstanding losses	957,961	972,293
IBNR	602,508	673,059
Fair value adjustments - acquired companies	(13,353)	(13,652)
Fair value adjustments - fair value option	(93,935)	(88,086)
ULAE	7,827
Total reinsurance reserves recoverable	1,461,008	1,543,614	1,579,646	1,366,123
Paid losses recoverable	137,210	181,375
Net	1,598,218	1,724,989
Reinsurance balances recoverable on paid and unpaid losses	944,822	1,029,471
Reinsurance balances recoverable on paid and unpaid losses - fair value option	653,396	695,518
Atrium
Effects of Reinsurance [Line Items]
Outstanding losses	8,140	9,011
IBNR	24,781	19,286
Fair value adjustments - acquired companies	514	519
Fair value adjustments - fair value option	0	0
ULAE	0
Total reinsurance reserves recoverable	33,435	28,816	31,682	38,768
Paid losses recoverable	1,181	1,541
Net	34,616	30,357
Reinsurance balances recoverable on paid and unpaid losses	34,616	30,357
Reinsurance balances recoverable on paid and unpaid losses - fair value option	0	0
StarStone
Effects of Reinsurance [Line Items]
Outstanding losses	321,921	328,009
IBNR	263,222	211,404
Fair value adjustments - acquired companies	(1,678)	(2,122)
Fair value adjustments - fair value option	0	0
ULAE	0
Total reinsurance reserves recoverable	583,465	537,291	$ 466,595	$ 462,950
Paid losses recoverable	103,478	87,253
Net	686,943	624,544
Reinsurance balances recoverable on paid and unpaid losses	686,943	624,544
Reinsurance balances recoverable on paid and unpaid losses - fair value option	$ 0	$ 0

Reinsurance Balances Recoverable on Paid and Unpaid Losses - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020	Dec. 31, 2019
Effects of Reinsurance [Line Items]
Reinsurance recoverable, allowance for credit loss	$ 143,327			$ 147,639
Reinsurance balances recoverable	2,319,777			2,379,890
Increase (decrease) in reinsurance recoverable	(57,860)	$ 256,706
Non-Life Run-Off and StarStone Segment
Effects of Reinsurance [Line Items]
Increase (decrease) in reinsurance recoverable	$ (60,100)
Cumulative effect of change in accounting principle
Effects of Reinsurance [Line Items]
Reinsurance recoverable, allowance for credit loss			$ 200	$ (195)

Reinsurance Balances Recoverable on Paid and Unpaid Losses - Top Ten Reinsurers (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($) reinsurer	Dec. 31, 2019 USD ($) reinsurer
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 2,319,777	$ 2,379,890
Top 10 reinsurers \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	1,531,266
Top 10 Total \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 1,260,977	$ 1,292,207
Number of external reinsurers \| reinsurer	8	8
Top Ten Reinsurers, Four Non-Rated Reinsurers \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 270,289	$ 272,125
Number of external reinsurers \| reinsurer	2	2
Reinsurance balances recoverable \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 2,319,777	$ 2,379,890
Concentration risk percentage	100.00%	100.00%
Reinsurance balances recoverable \| Top 10 reinsurers \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 1,531,266	$ 1,564,332
Concentration risk percentage	66.00%	65.70%
Reinsurance balances recoverable \| Other reinsurers greater than $1 million \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 772,373	$ 793,268
Concentration risk percentage	33.30%	33.40%
Reinsurance balances recoverable \| Other reinsurers less than $1 million \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 16,138	$ 22,290
Concentration risk percentage	0.70%	0.90%
Non-life Run-off
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 1,598,218	$ 1,724,989
Non-life Run-off \| Reinsurance balances recoverable \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	1,598,218	1,724,989
Non-life Run-off \| Reinsurance balances recoverable \| Top 10 reinsurers \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	1,075,150	1,154,110
Non-life Run-off \| Reinsurance balances recoverable \| Other reinsurers greater than $1 million \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	510,504	551,636
Non-life Run-off \| Reinsurance balances recoverable \| Other reinsurers less than $1 million \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	12,564	19,243
Atrium
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	34,616	30,357
Atrium \| Reinsurance balances recoverable \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	34,616	30,357
Atrium \| Reinsurance balances recoverable \| Top 10 reinsurers \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	25,328	22,051
Atrium \| Reinsurance balances recoverable \| Other reinsurers greater than $1 million \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	8,742	7,761
Atrium \| Reinsurance balances recoverable \| Other reinsurers less than $1 million \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	546	545
StarStone
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	686,943	624,544
StarStone \| Reinsurance balances recoverable \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	686,943	624,544
StarStone \| Reinsurance balances recoverable \| Top 10 reinsurers \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	430,788	388,171
StarStone \| Reinsurance balances recoverable \| Other reinsurers greater than $1 million \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	253,127	233,871
StarStone \| Reinsurance balances recoverable \| Other reinsurers less than $1 million \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	3,028	2,502
Equity Method Investee \| Hannover Ruck \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	264,424	261,295
Equity Method Investee \| Lloyds of London \| Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 412,790	$ 411,030

Reinsurance Balances Recoverable on Paid and Unpaid Losses - Summary of Provisions for Uncollectible Reinsurance Balances Recoverable by Rating of Reinsurer (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Effects of Reinsurance [Line Items]
Gross	$ 2,463,104	$ 2,527,529
Allowance for estimated uncollectible reinsurance	143,327	147,639
Net	$ 2,319,777	$ 2,379,890
Provisions as a % of Gross	5.80%	5.80%
Reinsurers rated A- or above
Effects of Reinsurance [Line Items]
Gross	$ 1,853,658	$ 1,904,268
Allowance for estimated uncollectible reinsurance	42,759	43,427
Net	$ 1,810,899	$ 1,860,841
Provisions as a % of Gross	2.30%	2.30%
Secured \| Reinsurers rated below A-
Effects of Reinsurance [Line Items]
Gross	$ 478,752	$ 487,608
Allowance for estimated uncollectible reinsurance	0	0
Net	$ 478,752	$ 487,608
Provisions as a % of Gross	0.00%	0.00%
Unsecured \| Reinsurers rated below A-
Effects of Reinsurance [Line Items]
Gross	$ 130,694	$ 135,653
Allowance for estimated uncollectible reinsurance	100,568	104,212
Net	$ 30,126	$ 31,441
Provisions as a % of Gross	76.90%	76.80%

Reinsurance Balances Recoverable on Paid and Unpaid Losses Reinsurance Balances Recoverable on Paid and Unpaid Losses - Allowance for Credit Loss (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for estimated uncollectible reinsurance, beginning of period	$ 147,639
Current period change in the allowance	(4,117)
Allowance for estimated uncollectible reinsurance, end of period	143,327
Cumulative effect of change in accounting principle
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for estimated uncollectible reinsurance, beginning of period	$ (195)

Deferred Charge Assets (Details) - USD ($)	3 Months Ended
Deferred Charge Assets (Details) - USD ($)	Mar. 31, 2020	Mar. 31, 2019
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning carrying value	$ 272,462,000	$ 86,585,000
Recorded during the period	0	20,632,000
Amortization	(14,630,000)	(7,063,000)
Ending carrying value	257,832,000	$ 100,154,000
Impairment loss of deferred charge assets	$ 0

- Definition

Amount of amortization expense (reversal of expense) for deferred policy acquisition costs.

+ References + Details

Losses and Loss Adjustment Expenses - Balance Sheet Summary by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	$ 5,321,032	$ 5,394,529
IBNR	5,187,459	5,057,868
Fair value adjustments - acquired companies	(157,620)	(167,511)
Fair value adjustments - fair value option	(274,642)	(217,933)
ULAE	353,758	362,285
Total	10,429,987	10,429,238	$ 10,096,022	$ 9,409,504
Loss and loss adjustment expenses	8,084,444	7,808,116
Loss and loss adjustment expenses, at fair value	2,345,543	2,621,122
Non-life Run-off
Liability for Claims and Claims Adjustment Expense [Line Items]
Total	8,216,850	8,295,361	8,154,974	7,540,662
Atrium
Liability for Claims and Claims Adjustment Expense [Line Items]
Total	243,610	231,672	229,380	241,284
StarStone
Liability for Claims and Claims Adjustment Expense [Line Items]
Total	1,947,014	1,879,128	$ 1,690,686	$ 1,608,697
Operating Segments \| Non-life Run-off
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	4,392,560	4,407,082
IBNR	3,937,751	3,945,407
Fair value adjustments - acquired companies	(161,040)	(170,689)
Fair value adjustments - fair value option	(274,642)	(217,933)
ULAE	322,221	331,494
Total	8,216,850	8,295,361
Loss and loss adjustment expenses	5,871,307	5,674,239
Loss and loss adjustment expenses, at fair value	2,345,543	2,621,122
Operating Segments \| Atrium
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	86,712	89,141
IBNR	150,666	136,543
Fair value adjustments - acquired companies	3,833	3,700
Fair value adjustments - fair value option	0	0
ULAE	2,399	2,288
Total	243,610	231,672
Loss and loss adjustment expenses	243,610	231,672
Loss and loss adjustment expenses, at fair value	0	0
Operating Segments \| StarStone
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	831,996	888,794
IBNR	1,086,293	962,353
Fair value adjustments - acquired companies	(413)	(522)
Fair value adjustments - fair value option	0	0
ULAE	29,138	28,503
Total	1,947,014	1,879,128
Loss and loss adjustment expenses	1,947,014	1,879,128
Loss and loss adjustment expenses, at fair value	0	0
Other
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	9,764	9,512
IBNR	12,749	13,565
Fair value adjustments - acquired companies	0	0
Fair value adjustments - fair value option	0	0
ULAE	0	0
Total	22,513	23,077
Loss and loss adjustment expenses	22,513	23,077
Loss and loss adjustment expenses, at fair value	$ 0	$ 0

Losses and Loss Adjustment Expenses - Reconciliation of Beginning and Ending Reserves for Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as at beginning of period	$ 10,429,238	$ 9,409,504
Less: reinsurance reserves recoverable	2,109,721	1,867,841
Less: deferred charges on retroactive reinsurance	272,462	86,585
Net balance as at beginning of period	8,046,860	7,455,078
Net incurred losses and LAE:
Current period	181,203	217,266
Prior periods	(73,309)	95,138
Total net incurred losses and LAE	107,894	312,404
Net paid losses:
Current period	(6,582)	(28,029)
Prior periods	(378,992)	(461,605)
Net losses paid	(385,574)	(489,634)
Effect of exchange rate movement	(146,083)	19,679
Assumed business	471,150	620,418
Net balance as of March 31	8,094,247	7,917,945
Plus: reinsurance reserves recoverable	2,077,908	2,077,923
Plus: deferred charges on retroactive reinsurance	257,832	100,154
Balance as of March 31	10,429,987	10,096,022
Non-life Run-off
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as at beginning of period	8,295,361	7,540,662
Less: reinsurance reserves recoverable	1,543,614	1,366,123
Less: deferred charges on retroactive reinsurance	272,462	86,585
Net balance as at beginning of period	6,479,988	6,087,954
Net incurred losses and LAE:
Current period	7,849	49,071
Prior periods	(69,883)	46,111
Total net incurred losses and LAE	(62,034)	95,182
Net paid losses:
Current period	(1,240)	(18,014)
Prior periods	(257,726)	(331,055)
Net losses paid	(258,966)	(349,069)
Effect of exchange rate movement	(132,128)	20,689
Assumed business	471,150	620,418
Net balance as of March 31	6,498,010	6,475,174
Plus: reinsurance reserves recoverable	1,461,008	1,579,646
Plus: deferred charges on retroactive reinsurance	257,832	100,154
Balance as of March 31	8,216,850	8,154,974
Atrium
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as at beginning of period	231,672	241,284
Less: reinsurance reserves recoverable	28,816	38,768
Net balance as at beginning of period	202,005	202,516
Net incurred losses and LAE:
Current period	27,904	18,237
Prior periods	512	(1,023)
Total net incurred losses and LAE	28,416	17,214
Net paid losses:
Current period	(4,285)	(7,893)
Prior periods	(12,723)	(14,420)
Net losses paid	(17,008)	(22,313)
Effect of exchange rate movement	(3,238)	281
Net balance as of March 31	210,175	197,698
Plus: reinsurance reserves recoverable	33,435	31,682
Balance as of March 31	243,610	229,380
StarStone
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as at beginning of period	1,879,128	1,608,697
Less: reinsurance reserves recoverable	537,291	462,950
Net balance as at beginning of period	1,341,790	1,145,747
Net incurred losses and LAE:
Current period	142,105	144,950
Prior periods	(3,075)	50,102
Total net incurred losses and LAE	139,030	195,052
Net paid losses:
Current period	(1,027)	(1,792)
Prior periods	(105,527)	(113,625)
Net losses paid	(106,554)	(115,417)
Effect of exchange rate movement	(10,717)	(1,291)
Net balance as of March 31	1,363,549	1,224,091
Plus: reinsurance reserves recoverable	583,465	466,595
Balance as of March 31	$ 1,947,014	$ 1,690,686
Cumulative effect of change in accounting principle
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance			$ 195	$ 0
Cumulative effect of change in accounting principle \| Non-life Run-off
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance			703	0
Cumulative effect of change in accounting principle \| Atrium
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance			851	0
Cumulative effect of change in accounting principle \| StarStone
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance			$ 47	$ 0

Losses and Loss Adjustment Expenses - Net (Reduction) Increase in Ultimate Losses and Loss Adjustment Expense Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Prior Period
Net losses paid	$ 378,992	$ 461,605
Net incurred losses and LAE, prior period	(73,309)	95,138
Current Period
Net losses paid	6,582	28,029
Net incurred losses and LAE, current period	181,203	217,266
Total
Net losses paid	385,574	489,634
Net change in case and LAE reserves	(217,381)	(75,463)
Net change in IBNR reserves	(18,820)	(160,762)
Increase (reduction) in estimates of net ultimate losses	149,373	253,409
Increase (reduction) in provisions for unallocated LAE	(6,738)	(13,827)
Amortization of deferred charges	14,630	7,064
Amortization of fair value adjustments	8,866	9,717
Changes in fair value - fair value option	(58,237)	56,041
Total net incurred losses and LAE	107,894	312,404
Non-life Run-off
Prior Period
Net losses paid	257,726	331,055
Net change in case and LAE reserves	(176,252)	(97,573)
Net change in IBNR reserves	(109,334)	(243,815)
Increase (reduction) in estimates of net ultimate losses	(27,860)	(10,333)
Increase (reduction) in provisions for unallocated LAE	(7,479)	(15,440)
Amortization of deferred charge assets	14,630	7,064
Amortization of fair value adjustments	9,063	8,779
Changes in fair value - fair value option	(58,237)	56,041
Net incurred losses and LAE, prior period	(69,883)	46,111
Current Period
Net losses paid	1,240	18,014
Net change in case and LAE reserves	1,672	19,872
Net change in IBNR reserves	4,937	10,920
Increase (reduction) in estimates of net ultimate losses	7,849	48,806
Increase (reduction) in provisions for unallocated LAE	0	265
Amortization of deferred charge assets	0	0
Amortization of fair value adjustments	0	0
Changes in fair value - fair value option	0	0
Net incurred losses and LAE, current period	7,849	49,071
Total
Net losses paid	258,966	349,069
Net change in case and LAE reserves	(174,580)	(77,701)
Net change in IBNR reserves	(104,397)	(232,895)
Increase (reduction) in estimates of net ultimate losses	(20,011)	38,473
Increase (reduction) in provisions for unallocated LAE	(7,479)	(15,175)
Amortization of deferred charges	14,630	7,064
Amortization of fair value adjustments	9,063	8,779
Changes in fair value - fair value option	(58,237)	56,041
Total net incurred losses and LAE	(62,034)	95,182
Atrium
Prior Period
Net losses paid	12,723	14,420
Net change in case and LAE reserves	(3,034)	(6,342)
Net change in IBNR reserves	(9,315)	(10,232)
Increase (reduction) in estimates of net ultimate losses	374	(2,154)
Amortization of fair value adjustments	138	1,131
Net incurred losses and LAE, prior period	512	(1,023)
Current Period
Net losses paid	4,285	7,893
Net change in case and LAE reserves	3,173	5,929
Net change in IBNR reserves	20,446	4,415
Increase (reduction) in estimates of net ultimate losses	27,904	18,237
Amortization of fair value adjustments	0	0
Net incurred losses and LAE, current period	27,904	18,237
Total
Net losses paid	17,008	22,313
Net change in case and LAE reserves	139	(413)
Net change in IBNR reserves	11,131	(5,817)
Increase (reduction) in estimates of net ultimate losses	28,278	16,083
Increase (reduction) in provisions for unallocated LAE	0	0
Amortization of deferred charges	0	0
Amortization of fair value adjustments	138	1,131
Changes in fair value - fair value option	0	0
Total net incurred losses and LAE	28,416	17,214
StarStone
Prior Period
Net losses paid	105,527	113,625
Net change in case and LAE reserves	(48,693)	(8,824)
Net change in IBNR reserves	(57,969)	(52,834)
Increase (reduction) in estimates of net ultimate losses	(1,135)	51,967
Increase (reduction) in provisions for unallocated LAE	(1,605)	(1,672)
Amortization of fair value adjustments	(335)	(193)
Net incurred losses and LAE, prior period	(3,075)	50,102
Current Period
Net losses paid	1,027	1,792
Net change in case and LAE reserves	5,501	10,880
Net change in IBNR reserves	133,231	129,258
Increase (reduction) in estimates of net ultimate losses	139,759	141,930
Increase (reduction) in provisions for unallocated LAE	2,346	3,020
Amortization of fair value adjustments	0	0
Net incurred losses and LAE, current period	142,105	144,950
Total
Net losses paid	106,554	115,417
Net change in case and LAE reserves	(43,192)	2,056
Net change in IBNR reserves	75,262	76,424
Increase (reduction) in estimates of net ultimate losses	138,624	193,897
Increase (reduction) in provisions for unallocated LAE	741	1,348
Amortization of deferred charges	0	0
Amortization of fair value adjustments	(335)	(193)
Changes in fair value - fair value option	0	0
Total net incurred losses and LAE	139,030	195,052
Other
Total
Net losses paid	3,046	2,835
Net change in case and LAE reserves	252	595
Net change in IBNR reserves	(816)	1,526
Increase (reduction) in estimates of net ultimate losses	2,482	4,956
Increase (reduction) in provisions for unallocated LAE	0	0
Amortization of deferred charges	0	0
Amortization of fair value adjustments	0	0
Changes in fair value - fair value option	0	0
Total net incurred losses and LAE	$ 2,482	$ 4,956

Losses and Loss Adjustment Expenses - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Effects of Reinsurance [Line Items]
Net incurred losses and LAE	$ 107,894	$ 312,404
Net incurred losses and LAE, current period	181,203	217,266
Prior periods	(73,309)	95,138
Net losses paid	378,992	461,605
Non-life Run-off
Effects of Reinsurance [Line Items]
Net incurred losses and LAE	(62,034)	95,182
Net incurred losses and LAE, current period	7,849	49,071
Prior periods	(69,883)	46,111
Changes in fair value - fair value option	(58,237)	56,041
Amortization of fair value adjustments	9,063	8,779
Amortization of deferred charge assets	14,630	7,064
Increase (reduction) in estimates of net ultimate losses	(27,860)	(10,333)
Increase (reduction) in provisions for unallocated LAE	(7,479)	(15,440)
Net change in case and IBNR reserves	(285,600)	(341,400)
Net losses paid	257,726	331,055
Atrium
Effects of Reinsurance [Line Items]
Net incurred losses and LAE	28,416	17,214
Net incurred losses and LAE, current period	27,904	18,237
Prior periods	512	(1,023)
Amortization of fair value adjustments	138	1,131
Increase (reduction) in estimates of net ultimate losses	374	(2,154)
Net losses paid	12,723	14,420
StarStone
Effects of Reinsurance [Line Items]
Net incurred losses and LAE	139,030	195,052
Net incurred losses and LAE, current period	142,105	144,950
Prior periods	(3,075)	50,102
Amortization of fair value adjustments	(335)	(193)
Increase (reduction) in estimates of net ultimate losses	(1,135)	51,967
Increase (reduction) in provisions for unallocated LAE	(1,605)	(1,672)
Net losses paid	105,527	$ 113,625
COVID-19 \| Atrium
Effects of Reinsurance [Line Items]
Net incurred losses and LAE, current period	8,600
COVID-19 \| StarStone
Effects of Reinsurance [Line Items]
Net incurred losses and LAE, current period	$ 32,100

Defendant Asbestos and Environmental Liabilities - Liability for Asbestos and Liability Claims (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Estimated future expenses	$ 49,607	$ 51,637
Fair value adjustments	(305,657)	(314,824)
Defendant asbestos and environmental liabilities	822,716	847,685	$ 197,512	$ 203,320
Insurance recoveries related to defendant asbestos and environmental liabilities	532,653	549,593
Fair value adjustments	(97,040)	(100,738)
Insurance balances recoverable	435,613	448,855	130,432	$ 135,808
Net liabilities relating to defendant asbestos and environmental exposures	387,103	398,830	$ 67,080
Defendant asbestos liabilities
Loss Contingencies [Line Items]
Defendant asbestos and environmental liabilities	1,068,620	1,100,593
Defendant environmental liabilities
Loss Contingencies [Line Items]
Defendant asbestos and environmental liabilities	$ 10,146	$ 10,279

Defendant Asbestos and Environmental Liabilities - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Balance as of beginning of period	$ 847,685	$ 203,320
Less: Insurance balances recoverable	448,855	135,808
Plus: Cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible insurance balances	6,985		$ 3,818
Net balance as of beginning of period	398,830
Total net paid claims	6,581	2,751
Amounts recorded in other (income) expense:
Change in estimate of ultimate net liabilities	(24,915)	(1,159)
Increase (reduction) in estimated future expenses	(2,028)	(2,125)
Amortization of fair value adjustments	5,468	101
Total other expense (income)	(21,475)	(3,183)
Net balance as at March 31	387,103	67,080
Plus: Insurance balances recoverable	435,613	130,432
Balance as at March 31	822,716	197,512
Cumulative effect of change in accounting principle
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Plus: Cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible insurance balances			$ 3,167	$ 0
Cumulative effect of change in accounting principle, adjusted balance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net balance as of beginning of period	$ 401,997	$ 67,512

Defendant Asbestos and Environmental Liabilities Defendant Asbestos and Environmental Liabilities - Allowance for Credit Loss (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Liability For Asbestos And Environmental Claims, Allowance for Credit Loss [Roll Forward]
Allowance for estimated uncollectible insurance balances, beginning of period	$ 3,818
Allowance for estimated uncollectible insurance balances, end of period	6,985	$ 3,818
Cumulative effect of change in accounting principle
Liability For Asbestos And Environmental Claims, Allowance for Credit Loss [Roll Forward]
Allowance for estimated uncollectible insurance balances, beginning of period	$ 3,167	0
Allowance for estimated uncollectible insurance balances, end of period		$ 3,167

Fair Value Measurements - Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reinsurance balances recoverable
Beginning fair value	$ 356,668	$ 321,973
Purchases	38,650
Sales	(539)	(3,589)
Total realized and unrealized losses	(40,513)	3,436
Transfer into Level 3 from Level 2		6,612
Transfer out of Level 3 into Level 2	(83,740)	(45,503)
Ending fair value	270,526	282,929
Corporate
Reinsurance balances recoverable
Beginning fair value		37,386
Sales		(2,660)
Total realized and unrealized losses		257
Transfer into Level 3 from Level 2		387
Transfer out of Level 3 into Level 2		(32,198)
Ending fair value		3,172
Commercial mortgage-backed
Reinsurance balances recoverable
Beginning fair value		7,389
Sales		(608)
Total realized and unrealized losses		62
Transfer into Level 3 from Level 2		0
Transfer out of Level 3 into Level 2		(6,843)
Ending fair value		0
Asset-backed
Reinsurance balances recoverable
Beginning fair value		9,121
Sales		(321)
Total realized and unrealized losses		737
Transfer into Level 3 from Level 2		6,225
Transfer out of Level 3 into Level 2		(6,462)
Ending fair value		9,300
Equities
Reinsurance balances recoverable
Beginning fair value	268,799	228,710
Purchases	1,358
Sales	0	0
Total realized and unrealized losses	(145)	0
Transfer into Level 3 from Level 2		0
Transfer out of Level 3 into Level 2	0	0
Ending fair value	270,012	228,710
Other Investments
Reinsurance balances recoverable
Beginning fair value	87,869	39,367
Purchases	37,292
Sales	(539)	0
Total realized and unrealized losses	(40,368)	2,380
Transfer into Level 3 from Level 2		0
Transfer out of Level 3 into Level 2	(83,740)	0
Ending fair value	$ 514	$ 41,747

Fair Value Measurements - Valuation Techniques (Details) - Private equities and private equity funds - Level 3 $ in Millions	Mar. 31, 2020 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments	$ 270.0
Minimum \| Transactional value \| Implied price at recent purchase transaction
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments, measurement input	13.50
Maximum \| Transactional value \| Implied price at recent purchase transaction
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments, measurement input	13.85

Fair Value Measurements - Insurance Contracts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Reinsurance balances recoverable
Beginning fair value	$ 356,668		$ 321,973
Assumed business	38,650
Incurred losses and LAE:
Change in fair value	(40,513)		3,436
Ending fair value	270,526	$ 356,668	282,929	$ 321,973
Net
Beginning fair value	1,925,604		2,134,464
Assumed business	4,975		0
Incurred losses and LAE:
Reduction in estimates of ultimate losses	(11,268)		(3,668)
Reduction in unallocated LAE	(6,413)		(4,341)
Change in fair value	(58,237)		56,041
Total incurred losses and LAE	(75,918)		48,032
Paid losses	(65,049)		(88,618)
Effect of exchange rate movements	(97,465)		18,658
Ending fair value	1,692,147	1,925,604	2,112,536	2,134,464
Losses and LAE liabilities
Liability for losses and LAE
Beginning fair value	2,621,122		2,874,055
Assumed business	4,975		0
Incurred losses and LAE:
Reduction in estimates of ultimate losses	(14,439)		(7,154)
Reduction in unallocated LAE	(6,413)		(4,341)
Change in fair value	(64,804)		77,461
Total incurred losses and LAE	(85,656)		65,966
Paid losses	(81,163)		(115,860)
Effect of exchange rate movements	(113,735)		23,632
Ending fair value	2,345,543	2,621,122	2,847,793	2,874,055
Reinsurance balances recoverable
Reinsurance balances recoverable
Beginning fair value	695,518		739,591
Assumed business	0		0
Incurred losses and LAE:
Reduction in estimates of ultimate losses	(3,171)		(3,486)
Reduction in unallocated LAE	0		0
Change in fair value	(6,567)		21,420
Total incurred losses and LAE	(9,738)		17,934
Paid losses	(16,114)		(27,242)
Effect of exchange rate movements	(16,270)		4,974
Ending fair value	653,396	695,518	735,257	739,591
Duration
Incurred losses and LAE:
Change in fair value	4,148		9,047
Corporate bond yield
Incurred losses and LAE:
Change in fair value	(64,092)		46,994
Weighted cost of capital
Incurred losses and LAE:
Change in fair value	$ (5,048)		$ 0
Risk cost of capital
Incurred losses and LAE:
Change in fair value		$ 6,755		$ 0

Fair Value Measurements - Observable and Unobservable Inputs (Details) - Internal Model - Recurring	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Losses and LAE liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average cost of capital	8.25%	8.50%
Duration	7 years 10 months 28 days	7 years 9 months 25 days
Reinsurance balances recoverable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Risk cost of capital	5.10%	5.10%
Duration	8 years 8 months 26 days	8 years 8 months 4 days
Measurement Input, Entity Credit Risk \| Losses and LAE liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit spread for non-performance risk	0.20%	0.20%

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	May 28, 2019	Mar. 10, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, amortized cost	$ 1,541,554	$ 1,191,207
Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, amortized cost	$ 842,437	842,216
4.50% Senior Notes due 2022 \| Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	4.50%			4.50%
Debt, amortized cost	$ 348,794	348,616
Debt, fair value	$ 347,000
4.95% Senior Notes due 2029 \| Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	4.95%		4.95%
Debt, amortized cost	$ 493,643	$ 493,600
Debt, fair value	$ 475,000

Premiums Written and Earned - Schedule of Net Premiums Written and Earned (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Effects of Reinsurance [Line Items]
Gross, premiums written	$ 334,133	$ 285,345
Ceded, premiums written	(97,445)	(62,578)
Net, premiums written	236,688	222,767
Gross, premiums earned	326,691	402,289
Ceded premium earned	(66,794)	(67,002)
Net, premiums earned	259,897	335,287
Operating Segments \| Non-life Run-off
Effects of Reinsurance [Line Items]
Gross, premiums written	327	(20,877)
Ceded, premiums written	1,849	1,699
Net, premiums written	2,176	(19,178)
Gross, premiums earned	18,078	83,966
Ceded premium earned	(2,048)	(7,292)
Net, premiums earned	16,030	76,674
Operating Segments \| Atrium
Effects of Reinsurance [Line Items]
Gross, premiums written	57,837	53,985
Ceded, premiums written	(9,139)	(7,486)
Net, premiums written	48,698	46,499
Gross, premiums earned	47,833	43,386
Ceded premium earned	(5,463)	(4,633)
Net, premiums earned	42,370	38,753
Operating Segments \| StarStone
Effects of Reinsurance [Line Items]
Gross, premiums written	279,854	251,373
Ceded, premiums written	(90,819)	(56,772)
Net, premiums written	189,035	194,601
Gross, premiums earned	258,107	268,264
Ceded premium earned	(59,947)	(55,002)
Net, premiums earned	198,160	213,262
Other
Effects of Reinsurance [Line Items]
Gross, premiums written	(3,885)	864
Ceded, premiums written	664	(19)
Net, premiums written	(3,221)	845
Gross, premiums earned	2,673	6,673
Ceded premium earned	664	(75)
Net, premiums earned	$ 3,337	$ 6,598

Premiums Written and Earned - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Gross, premiums written	$ 334,133	$ 285,345
Increase in gross premiums written	48,800
Starstone
Segment Reporting Information [Line Items]
Increase in gross premiums written	$ 28,500
Non-life Run-off
Segment Reporting Information [Line Items]
Increase in gross premiums written		$ 21,200

Goodwill and Intangible Assets - Schedule of Goodwill and Intangible Assets (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Goodwill
Balance as of January 1, 2020	$ 114,807
Balance as of March 31, 2020	114,807
Intangible assets with a definite life
Balance as of January 1, 2020	14,630
Amortization	(508)
Balance as of March 31, 2020	14,122
Intangible assets with an indefinite life
Balance as of January 1, 2020	87,031
Balance as of March 31, 2020	87,031
Intangible Assets [Roll Forward]
Balance as of January 1, 2020	101,661
Amortization	(508)
Balance as of March 31, 2020	101,153
Goodwill and Intangible Assets [Roll Forward]
Balance as of January 1, 2020	216,468
Balance as of March 31, 2020	$ 215,960

Goodwill and Intangible Assets - Intangible Asset Amortization (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 508	$ 565

Goodwill and Intangible Assets - Summary of Gross Carrying Value, Accumulated Amortization and Net Carrying Value of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Intangible assets with a definite life:
Gross Carrying Value	$ 27,000	$ 27,000
Accumulated Amortization	(12,878)	(12,370)
Net Carrying Value	14,122	14,630
Indefinite-lived Intangible Assets [Line Items]
Intangible assets with an indefinite life, Carrying Value	87,031	87,031
Lloyd’s syndicate capacity
Indefinite-lived Intangible Assets [Line Items]
Intangible assets with an indefinite life, Carrying Value	37,031	37,031
Licenses
Indefinite-lived Intangible Assets [Line Items]
Intangible assets with an indefinite life, Carrying Value	19,900	19,900
Management contract
Indefinite-lived Intangible Assets [Line Items]
Intangible assets with an indefinite life, Carrying Value	30,100	30,100
Distribution channel
Intangible assets with a definite life:
Gross Carrying Value	20,000	20,000
Accumulated Amortization	(8,444)	(8,111)
Net Carrying Value	11,556	11,889
Brand
Intangible assets with a definite life:
Gross Carrying Value	7,000	7,000
Accumulated Amortization	(4,434)	(4,259)
Net Carrying Value	$ 2,566	$ 2,741

Debt Obligations and Credit Facilities - Amounts Outstanding and Accrued Interest (Details) - USD ($) $ in Thousands			3 Months Ended
	Dec. 27, 2018	Aug. 16, 2018	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	May 28, 2019	Mar. 10, 2017
Debt Instrument [Line Items]
Debt, amortized cost			$ 1,541,554		$ 1,191,207
Interest expense on debt obligations			13,195	$ 10,453
Amortization of debt issuance costs			220	273
Funds withheld balances and other			0	310
Total interest expense			13,415	$ 11,036
Senior Notes
Debt Instrument [Line Items]
Debt, amortized cost			$ 842,437		842,216
Senior Notes \| 4.50% Senior Notes due 2022
Debt Instrument [Line Items]
Stated interest rate			4.50%				4.50%
Term			5 years
Debt, amortized cost			$ 348,794		348,616
Senior Notes \| 4.95% Senior Notes due 2029
Debt Instrument [Line Items]
Stated interest rate			4.95%			4.95%
Term			10 years
Debt, amortized cost			$ 493,643		493,600
Line of Credit \| EGL Revolving Credit Facility
Debt Instrument [Line Items]
Term		5 years	5 years
Debt, amortized cost			$ 350,000		0
Line of Credit \| 2018 EGL Term Loan Facility
Debt Instrument [Line Items]
Term	3 years		3 years
Debt, amortized cost			$ 349,117		$ 348,991

Debt Obligations and Credit Facilities - Additional Information (Details) - USD ($)						3 Months Ended		5 Months Ended	12 Months Ended
	Nov. 06, 2019	May 28, 2019	Dec. 27, 2018	Aug. 16, 2018	Mar. 10, 2017	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2019	May 07, 2020	Dec. 09, 2019	Dec. 06, 2019	Dec. 05, 2019	Feb. 12, 2019
Line of Credit Facility [Line Items]
Receipt of loans						$ 364,000,000	$ 344,000,000
Repayment of loans						14,000,000	$ 102,000,000
Debt, amortized cost						1,541,554,000		$ 1,191,207,000	$ 1,191,207,000
Cash and investments						718,000,000.0		639,300,000	639,300,000
Maiden Facility Agreement
Line of Credit Facility [Line Items]
Proceeds from credit facility agreement								447,400,000
Senior Notes
Line of Credit Facility [Line Items]
Debt, amortized cost						$ 842,437,000		842,216,000	842,216,000
Senior Notes \| 4.50% Senior Notes due 2022
Line of Credit Facility [Line Items]
Stated interest rate					4.50%	4.50%
Outstanding amount of debt					$ 350,000,000.0
Redemption price percentage					100.00%
Payments of debt issuance costs					$ 2,900,000
Unamortized costs						$ 1,200,000		1,400,000	1,400,000
Term of debt						5 years
Debt, amortized cost						$ 348,794,000		348,616,000	348,616,000
Senior Notes \| 4.95% Senior Notes due 2029
Line of Credit Facility [Line Items]
Stated interest rate		4.95%				4.95%
Outstanding amount of debt		$ 500,000,000.0
Redemption price percentage		100.00%
Payments of debt issuance costs		$ 6,800,000
Unamortized costs						$ 6,400,000		6,400,000	6,400,000
Term of debt						10 years
Debt, amortized cost						$ 493,643,000		493,600,000	493,600,000
Line of Credit
Line of Credit Facility [Line Items]
Receipt of loans						364,000,000.0
Repayment of loans						$ 14,000,000.0
Line of Credit \| 2018 EGL Revolving Credit Facility
Line of Credit Facility [Line Items]
Term of debt				5 years		5 years
Maximum borrowing capacity				$ 600,000,000.0		$ 600,000,000.0
Optional increase in borrowing capacity				$ 400,000,000.0
Debt, amortized cost						350,000,000		0	0
Line of credit facility, remaining borrowing capacity						250,000,000.0
Line of Credit \| 2018 EGL Revolving Credit Facility \| Subsequent Event
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity										$ 250,000,000.0
Line of Credit \| 2018 EGL Term Loan Facility
Line of Credit Facility [Line Items]
Repayment of loans									150,000,000.0
Payments of debt issuance costs			$ 1,500,000
Unamortized costs						$ 900,000		1,000,000.0	1,000,000.0
Term of debt			3 years			3 years
Maximum borrowing capacity			$ 500,000,000.0
Optional increase in borrowing capacity			$ 150,000,000.0
Debt, amortized cost						$ 349,117,000		348,991,000	348,991,000
Line of credit facility, remaining borrowing capacity						349,100,000
Interest payment period			3 months
Line of Credit \| FAL Facility
Line of Credit Facility [Line Items]
Higher borrowing capacity option														$ 400,000,000.0
Letters of Credit \| Line of Credit \| FAL Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity						252,000,000.0								375,000,000.0
Optional increase in borrowing capacity														$ 25,000,000.0
Term extension	1 year
Letters of Credit \| Line of Credit \| 2018 Facility Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity												$ 120,000,000.0	$ 170,000,000.0
Optional increase in borrowing capacity												$ 60,000,000.0
Letters of credit						115,300,000		115,300,000	115,300,000
Letters of Credit \| Line of Credit \| Maiden Facility Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity								760,000,000.0	760,000,000.0
Optional increase in borrowing capacity											$ 40,000,000.0
Letters of credit						$ 610,400,000		$ 608,000,000.0	$ 608,000,000.0

Noncontrolling Interests - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Noncontrolling Interest [Line Items]
Noncontrolling interest	$ 13,405	$ 14,168
Trident \| Subsidiaries
Noncontrolling Interest [Line Items]
Interest owned by an entity (percent)	39.30%		39.30%
Dowling \| Subsidiaries
Noncontrolling Interest [Line Items]
Interest owned by an entity (percent)	1.70%		1.70%

Noncontrolling Interests - Carrying Amount of Equity Attributable to Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Increase (Decrease) in Redeemable Noncontrolling Interest [Roll Forward]
Balance at beginning of period	$ 438,791	$ 458,543
Net losses attributable to RNCI	(31,959)	(2,544)
Accumulated other comprehensive earnings (losses) attributable to RNCI	(4,170)	85
Change in redemption value of RNCI	(10,150)	262
Cumulative effect of change in accounting principle attributable to RNCI (1)	261	0
Balance at end of period	$ 392,773	$ 456,346

Share Capital (Details) - USD ($)					3 Months Ended
Share Capital (Details) - USD ($)	May 05, 2020	Mar. 23, 2020	Feb. 04, 2020	Jan. 21, 2020	Mar. 31, 2020	Mar. 31, 2019	Mar. 09, 2020
Class of Stock [Line Items]
Total dividends paid					$ 8,925,000	$ 9,139,000
Repurchase authorized amount							$ 150,000,000.0
Shares repurchased (in shares)		92,510
Shares repurchased, value		$ 12,500,000			$ 12,526,000	$ 0
Average price per share (dollars per share)		$ 135.40
Series D Preferred Stock
Class of Stock [Line Items]
Declared cash dividends (in dollars per share)			$ 437.50
Declared cash dividends (in dollars per depositary share)			$ 0.43750
Total dividends paid			$ 7,000,000
Series E Preferred Stock
Class of Stock [Line Items]
Declared cash dividends (in dollars per share)			$ 437.50
Declared cash dividends (in dollars per depositary share)			$ 0.43750
Total dividends paid			$ 1,925,000
Subsequent Event \| Series D Preferred Stock
Class of Stock [Line Items]
Declared cash dividends (in dollars per share)	$ 437.50
Declared cash dividends (in dollars per depositary share)	$ 0.43750
Total dividends paid	$ 0
Subsequent Event \| Series E Preferred Stock
Class of Stock [Line Items]
Declared cash dividends (in dollars per share)	$ 437.50
Declared cash dividends (in dollars per depositary share)	$ 0.43750
Total dividends paid	$ 0
Joint Share Ownership Plan
Class of Stock [Line Items]
Grant date fair value				$ 13,600,000
Grant date fair value (dollars per share)				$ 24.13
Volatility				18.66%
Dividend yield				0.00%
Risk-free interest rate				1.55%
Joint Share Ownership Plan \| Chief Executive Officer
Class of Stock [Line Items]
Shares subscribed (shares)				565,630
Vesting period				3 years

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net earnings (loss)	$ (516,821)	$ 358,751
Denominator:
Weighted-average ordinary shares outstanding — basic (in shares)	21,549,844	21,463,499
Effect of dilutive securities:
Share-based compensation plans (in shares)	164,435	122,980
Warrants (in shares)	65,627	59,383
Weighted-average ordinary shares outstanding — diluted (in shares)	21,779,906	21,645,862
Basic:
Basic net earnings (losses) per ordinary share (in dollars per share)	$ (23.98)	$ 16.71
Diluted
Diluted net earnings (loss) per ordinary share (in dollars per share)	$ (23.98)	$ 16.57

Share-Based Compensation and Pensions - Compensation Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ (136)	$ 5,200
Restricted shares and restricted share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	1,599	1,843
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	(667)	1,325
Cash-settled stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	(3,159)	56
Employee share purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	104	103
Joint share ownership plan expense \| Employee share purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	872	0
Northshore incentive plan \| Northshore incentive plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	472	1,046
StarStone incentive plan \| Northshore incentive plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	(223)	0
Restricted Stock Units (RSUs) \| Director \| Deferred Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred compensation and ordinary share plan for non-employee directors	$ 866	$ 827

Income Taxation (Details) - USD ($)	3 Months Ended
Income Taxation (Details) - USD ($)	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Effective tax rate expense (benefit)	0.90%	1.30%
Statutory rate	0.00%
Deferred tax	$ 1,800,000
Unrecognized tax benefits	$ 0		$ 0

Related Party Transactions - Stone Point Capital LLC (Details) $ in Thousands				3 Months Ended			12 Months Ended
	Oct. 01, 2019 USD ($)	Apr. 01, 2019 USD ($)	Oct. 01, 2018 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Jul. 31, 2012 shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 06, 2013 general_partner
Related Party Transaction [Line Items]
Assumed business				$ 471,150	$ 620,418
Adverse development cover	$ 59,000
Redeemable noncontrolling interest				392,773	456,346		$ 438,791	$ 458,543
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value				2,279,073			2,041,724
Equities, at fair value				641,850			729,721
Other investments, at fair value				2,326,984			2,524,420
Cash and cash equivalents				815,878	718,050		703,085
Other assets				823,121			744,608
Other liabilities				431,204			464,014
Related Party, Consolidated Statement of Earnings [Abstract]
Net realized and unrealized gains (losses)				(634,476)	460,791
NET EARNINGS (LOSS)				(540,618)	365,742		(540,618)
Short-term Investments
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value				138,900			128,335
Trading, at fair value				18,249			51,490
Fixed Maturities
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value				2,140,173			1,913,389
Trading, at fair value				5,644,819			6,346,329
Hedge funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				1,055,448			1,121,904
Fixed income funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				463,717			481,039
Private equities and private equity funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				309,219			329,885
CLO equities
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				83,740			87,555
CLO equity funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				66,938			87,509
Trident \| Affiliated Entity
Related Party Transaction [Line Items]
Related party transaction, shares acquired (in shares) \| shares						1,635,986
Number of newly elected board of directors \| general_partner									1
Number of general partners \| general_partner									4
Redeemable noncontrolling interest				376,399			420,499
Starstone
Related Party Transaction [Line Items]
Assumed business	189,400
Reinsurance premium consideration	$ 189,400
StonePoint And Affiliated Entities
Related Party, Consolidated Balance Sheet [Abstract]
Equities, at fair value				91,820			121,794
Cash and cash equivalents				55,391			54,080
Other assets				346			10
Other liabilities				457			4,710
Related Party, Consolidated Statement of Earnings [Abstract]
Net investment income				4,084	1,075
Net realized and unrealized gains (losses)				(102,516)	20,133
NET EARNINGS (LOSS)				(98,432)	$ 21,208
StonePoint And Affiliated Entities \| Short-term Investments
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value				1,134			1,431
StonePoint And Affiliated Entities \| Fixed Maturities
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value				199,563			160,303
Trading, at fair value				208,255			269,131
StonePoint And Affiliated Entities \| Hedge funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				16,501			18,993
StonePoint And Affiliated Entities \| Fixed income funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				310,397			381,449
StonePoint And Affiliated Entities \| Private equities and private equity funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				32,241			34,858
StonePoint And Affiliated Entities \| CLO equities
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				31,842			32,560
StonePoint And Affiliated Entities \| CLO equity funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				66,938			87,509
StonePoint And Affiliated Entities \| Private Debt
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				16,528			16,312
StonePoint And Affiliated Entities \| Real estate fund
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value				$ 21,644			$ 18,106
Stone Point \| Affiliated Entity
Related Party Transaction [Line Items]
Ownership percentage				8.80%
Trident \| North Bay
Related Party Transaction [Line Items]
Payments to acquire investments			$ 53,100
North Bay Shareholders \| North Bay
Related Party Transaction [Line Items]
Payments to acquire investments		$ 48,000	$ 135,000
Mitchell International \| Affiliated Entity
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value								$ 25,000

Related Party Transactions - Hillhouse (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Other investments	$ 2,326,984	$ 2,524,420
Ownership percentage	47.40%	47.40%
Hillhouse Affiliates \| Affiliated Entity
Related Party Transaction [Line Items]
Ownership percentage	9.40%
Economic interest percentage	16.50%
Hillhouse
Related Party Transaction [Line Items]
Other investments	$ 1,082,398	$ 1,151,601
Hillhouse \| Affiliated Entity
Related Party Transaction [Line Items]
Other investments	180,443	155,377
Fees incurred	2,300
Hillhouse \| Hillhouse Affiliates \| Affiliated Entity
Related Party Transaction [Line Items]
Other investments	380,681	327,799
InRe Fund \| Hillhouse \| Affiliated Entity
Related Party Transaction [Line Items]
Other investments	869,275	918,633
Other Funds \| Hillhouse \| Affiliated Entity
Related Party Transaction [Line Items]
Other investments	$ 213,123	$ 232,968
Fixed Income Securities \| Hillhouse InRe Fund, L.P. \| Affiliated Entity
Related Party Transaction [Line Items]
Other investments, percentage of funds	30.00%
North American Equities \| Hillhouse InRe Fund, L.P. \| Affiliated Entity
Related Party Transaction [Line Items]
Other investments, percentage of funds	15.00%
International Equities \| Hillhouse InRe Fund, L.P. \| Affiliated Entity
Related Party Transaction [Line Items]
Other investments, percentage of funds	80.00%
Financing, Derivatives And Other Items \| Hillhouse InRe Fund, L.P. \| Affiliated Entity
Related Party Transaction [Line Items]
Other investments, percentage of funds	(25.00%)

Related Party Transactions - Monument (Details) $ in Thousands, € in Millions	3 Months Ended		42 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	May 31, 2019 USD ($)	May 31, 2019 EUR (€)
Related Party Transaction [Line Items]
Contributed amount of common and preferred shares	$ 0	$ 9,762
Ownership percentage	47.40%		47.40%	47.40%
Carrying value of previously held equity method investment prior to the close of the transaction	$ 337,474		$ 337,474	$ 326,277
Monument
Related Party Transaction [Line Items]
Contributed amount of common and preferred shares			$ 26,600
Ownership percentage	26.60%		26.60%	26.60%
Carrying value of previously held equity method investment prior to the close of the transaction	$ 57,737		$ 57,737	$ 60,598
Transfer Of Life Assurance Policies \| Subsidiary Of Monument
Related Party Transaction [Line Items]
Policy benefits transferred					$ 99,100	€ 88.8
Total assets transferred					$ 101,600	€ 91.1

Related Party Transactions - Clear Spring (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	Jan. 01, 2017	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Capitalized amount of investment	$ 56,000
Ownership percentage		47.40%		47.40%
Carrying value of previously held equity method investment prior to the close of the transaction		$ 337,474		$ 326,277
Balances under StarStone ceding quota share:
Reinsurance balances recoverable		2,319,777		2,379,890
Losses and LAE
Losses and LAE		10,429,987	$ 10,096,022	10,429,238	$ 9,409,504
Unearned reinsurance premiums		760,307		746,775
Funds held		827,382		408,735
Transactions under StarStone ceding quota share:
Ceded premium earned		(66,794)	(67,002)
Acquisition costs		(66,586)	(93,788)
Transactions under assuming quota share:
Net incurred losses and LAE		107,894	312,404
Net earnings (loss)		$ (540,618)	365,742	(540,618)
Clear Spring \| Equity Method Investee
Related Party Transaction [Line Items]
Ownership percentage		20.00%
Balances under StarStone ceding quota share:
Reinsurance balances recoverable		$ 23,566		22,812
Prepaid insurance premiums		12		51
Ceded payable		4,189		3,616
Ceded acquisition costs		0		21
Clear Spring \| Affiliated Entity
Transactions under assuming quota share:
Net earnings (loss)		674	(1,180)
Starstone \| Clear Spring
Related Party Transaction [Line Items]
Carrying value of previously held equity method investment prior to the close of the transaction		10,952		10,645
Percentage of business reinsured	33.30%
Starstone \| Clear Spring \| Affiliated Entity
Transactions under StarStone ceding quota share:
Ceded premium earned		(681)	(5,485)
Ceded incurred losses and LAE		754	3,859
Acquisition costs		(72)	(54)
Starstone \| Cavello Bay
Related Party Transaction [Line Items]
Percentage of business reinsured	25.00%
Cavello Bay \| Clear Spring
Losses and LAE
Losses and LAE		5,307		6,135
Unearned reinsurance premiums		3		13
Funds held		8,303		$ 8,611
Cavello Bay \| Clear Spring \| Affiliated Entity
Transactions under StarStone ceding quota share:
Acquisition costs		(13)	(14)
Transactions under assuming quota share:
Premium earned		170	1,371
Net incurred losses and LAE		$ 372	$ (965)

Related Party Transactions - AmTrust (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
	Dec. 31, 2019	Nov. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Purchase amount of equity interest			$ 0	$ 9,762
Net investment income			77,840	78,696	$ 78,696
Net realized and unrealized gains (losses)			(634,476)	460,791
AmTrust Financial Services, Inc.
Related Party Transaction [Line Items]
Investment in related party	$ 240,100		241,300		240,100
AmTrust Financial Services, Inc. \| Affiliated Entity
Related Party Transaction [Line Items]
Ownership percentage		45.00%
Trident Pine \| Evergreen Parent L.P. \| Affiliated Entity
Related Party Transaction [Line Items]
Capital units ownership percentage		21.80%
Evergreen Parent L.P. \| Affiliated Entity
Related Party Transaction [Line Items]
Purchase amount of equity interest	25,900	$ 200,000
Capital units ownership percentage		8.50%
Management fee income						$ 3,300
AmTrust Financial Services, Inc. \| Affiliated Entity
Related Party Transaction [Line Items]
Investment in related party	$ 240,115		241,328		$ 240,115
Net investment income			2,500	1,800
Net realized and unrealized gains (losses)			$ (100)	$ 0

Related Party Transactions - Citco (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Indirect investment acquired		$ 160,814	$ 225,961
Other investments		$ 2,326,984		$ 2,524,420
Trident \| Citco \| Affiliated Entity
Related Party Transaction [Line Items]
Indirect investment acquired	$ 50,000
Ownership percentage		3.40%
Citco
Related Party Transaction [Line Items]
Other investments		$ 51,504		$ 51,742

Related Party Transactions - Enhanzed Re (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Equity method investments	$ 337,474		$ 326,277
Ownership percentage	47.40%		47.40%
Balances under ceding quota share:
Insurance balances payables	$ 451,530		$ 373,180
Reinsurance balances recoverable	2,319,777		2,379,890
Funds held	827,382		408,735
Other Assets	823,121		744,608
Premiums Earned, Net [Abstract]
Acquisition costs	66,586	$ 93,788
Total net earnings	(540,618)	365,742	(540,618)
Enstar \| Enhanzed Re
Related Party Transaction [Line Items]
Equity method investments	154,100
Ownership percentage				47.40%
Uncalled amount of investment	68,700
Allianz \| Enhanzed Re
Related Party Transaction [Line Items]
Ownership percentage				24.90%
Hillhouse \| Enhanzed Re
Related Party Transaction [Line Items]
Ownership percentage				27.70%
Enhanzed Re
Related Party Transaction [Line Items]
Equity method investments	$ 197,206		$ 182,856
Ownership percentage	47.40%		47.40%
Enhanzed Re \| Affiliated Entity
Related Party Transaction [Line Items]
Equity method investments				$ 470,000
Balances under ceding quota share:
Insurance balances payables	$ 1,519		$ 1,443
Reinsurance balances recoverable	58,022		59,601
Funds held	48,383		50,089
Other Assets	400		$ 1,033
Premiums Earned, Net [Abstract]
Acquisition costs	23	0
Other income	291	86
Total net earnings	$ 314	$ 86
Enhanzed Re \| Zurich
Related Party Transaction [Line Items]
Percentage ceded	10.00%

Commitments and Contingencies - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Feb. 12, 2019
Guarantor Obligations [Line Items]
Funds held by reinsured companies	$ 827,382,000	$ 408,735,000
Lease optional renewal period	5 years
Lease optional termination period	1 year
Limited Parental Guarantee
Guarantor Obligations [Line Items]
Parental guarantees	$ 1,300,000,000	$ 1,000,000,000.0
US
Guarantor Obligations [Line Items]
Concentration of credit risk, counterparty credit exposure	872,400,000
Reinsurance Recoverables \| Reinsurer Concentration Risk
Guarantor Obligations [Line Items]
Funds held by reinsured companies	941,500,000
Line of Credit \| FAL Facility
Guarantor Obligations [Line Items]
Higher borrowing capacity option			$ 400,000,000.0
Line of Credit \| FAL Facility \| Letters of Credit
Guarantor Obligations [Line Items]
Maximum borrowing capacity	252,000,000.0		$ 375,000,000.0
Private equities and private equity funds
Guarantor Obligations [Line Items]
Commitments, unfunded	773,600,000
Equity Method Investments
Guarantor Obligations [Line Items]
Commitments, unfunded	$ 110,500,000
Minimum
Guarantor Obligations [Line Items]
Weighted-average remaining lease term	1 year
Maximum
Guarantor Obligations [Line Items]
Weighted-average remaining lease term	37 years

Commitments and Contingencies - Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 3,322	$ 3,487
Short-term lease cost	58	0
Total lease cost	3,380	3,487
Sublease income	(138)	(131)
Total lease cost	3,242	3,356
Operating Cash paid for amounts included in the measurement of lease liabilities	3,183	3,024
Non-cash activity: right-of-use assets relating to leases	$ 72	$ 51,609
Weighted-average remaining lease term	6 years 2 months 12 days		6 years 7 months 6 days
Weighted-average discount rate	6.30%		6.20%

Commitments and Contingencies - Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Right-of-use assets	$ 39,300	$ 46,747
Current lease liabilities	10,467	11,403
Non-current lease liabilities	$ 31,319	$ 34,785

Commitments and Contingencies - Leases - Operating Lease Liabilities (Details) $ in Thousands	Mar. 31, 2020 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2020	$ 9,938
2021	9,578
2022	7,893
2023	6,873
2024	5,147
2025 and beyond	12,205
Total lease payments	51,634
Less: Imputed interest	(9,848)
Present value of lease liabilities	$ 41,786

Segment Information - Additional Information (Details)	3 Months Ended
Segment Information - Additional Information (Details)	Mar. 31, 2020 Segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment Information - Summary of Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Gross premiums written	$ 334,133	$ 285,345
Net premiums written	236,688	222,767
Net premiums earned	259,897	335,287
Net incurred losses and LAE	(107,894)	(312,404)
Life and Annuity Policy Benefits	0	(96)
Acquisition costs	(66,586)	(93,788)
Operating expenses	(85,639)	(83,019)
Underwriting income (loss)	(222)	(154,020)
Net investment income	77,840	78,696	$ 78,696
Net realized and unrealized gains (losses)	(634,476)	460,791
Fees and commission income	7,528	6,681
Other income	20,444	5,812
Corporate expenses	(27,872)	(29,055)
Interest income (expense)	(13,415)	(11,036)
Net foreign exchange gains (losses)	11,930	3,850
EARNINGS (LOSS) BEFORE INCOME TAXES	(558,243)	361,719
Income tax benefit (expense)	5,175	(4,749)
Earnings from equity method investments	12,450	8,772
NET EARNINGS (LOSS)	(540,618)	365,742	(540,618)
Net loss attributable to noncontrolling interest	32,722	2,148
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR	(507,896)	367,890
Dividends on preferred shares	(8,925)	(9,139)
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	(516,821)	358,751
Non-life Run-off
Segment Reporting Information [Line Items]
Net incurred losses and LAE	62,034	(95,182)
NET EARNINGS (LOSS)			(451,113)
Atrium
Segment Reporting Information [Line Items]
Net incurred losses and LAE	$ (28,416)	$ (17,214)
NET EARNINGS (LOSS)			(9,430)
Underwriting Ratios [Abstract]
Loss ratio	67.10%	44.40%
Acquisition expense ratio	33.90%	35.50%
Operating expense ratio	6.80%	7.80%
Combined ratio	107.80%	87.70%
StarStone
Segment Reporting Information [Line Items]
Net incurred losses and LAE	$ (139,030)	$ (195,052)
NET EARNINGS (LOSS)			(63,279)
Underwriting Ratios [Abstract]
Loss ratio	70.20%	91.50%
Acquisition expense ratio	22.80%	24.20%
Operating expense ratio	17.40%	16.90%
Combined ratio	110.40%	132.60%
Operating Segments \| Non-life Run-off
Segment Reporting Information [Line Items]
Gross premiums written	$ 327	$ (20,877)
Net premiums written	2,176	(19,178)
Net premiums earned	16,030	76,674
Net incurred losses and LAE	62,034	(95,182)
Life and Annuity Policy Benefits		0
Acquisition costs	(6,907)	(28,155)
Operating expenses	(48,210)	(43,992)
Underwriting income (loss)	22,947	(90,655)
Net investment income	67,451	66,728
Net realized and unrealized gains (losses)	(574,682)	436,186
Fees and commission income	4,985	4,832
Other income	22,295	5,504
Corporate expenses	(8,120)	(16,570)
Interest income (expense)	(15,899)	(12,116)
Net foreign exchange gains (losses)	14,653	3,618
EARNINGS (LOSS) BEFORE INCOME TAXES	(466,370)	397,527
Income tax benefit (expense)	2,807	(2,720)
Earnings from equity method investments	12,450	8,584
NET EARNINGS (LOSS)		403,391
Net loss attributable to noncontrolling interest	2,087	(2,646)
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR	(449,026)	400,745
Dividends on preferred shares	0	0
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	(449,026)	400,745
Operating Segments \| Atrium
Segment Reporting Information [Line Items]
Gross premiums written	57,837	53,985
Net premiums written	48,698	46,499
Net premiums earned	42,370	38,753
Net incurred losses and LAE	(28,416)	(17,214)
Life and Annuity Policy Benefits		0
Acquisition costs	(14,384)	(13,742)
Operating expenses	(2,877)	(3,033)
Underwriting income (loss)	(3,307)	4,764
Net investment income	1,525	1,711
Net realized and unrealized gains (losses)	(5,708)	2,913
Fees and commission income	2,543	1,849
Other income	35	36
Corporate expenses	(3,138)	(3,788)
Interest income (expense)	0	0
Net foreign exchange gains (losses)	(2,133)	825
EARNINGS (LOSS) BEFORE INCOME TAXES	(10,183)	8,310
Income tax benefit (expense)	753	(685)
Earnings from equity method investments	0	0
NET EARNINGS (LOSS)		7,625
Net loss attributable to noncontrolling interest	3,868	(3,128)
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR	(5,562)	4,497
Dividends on preferred shares	0	0
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	(5,562)	4,497
Operating Segments \| StarStone
Segment Reporting Information [Line Items]
Gross premiums written	279,854	251,373
Net premiums written	189,035	194,601
Net premiums earned	198,160	213,262
Net incurred losses and LAE	(139,030)	(195,052)
Life and Annuity Policy Benefits		0
Acquisition costs	(45,212)	(51,659)
Operating expenses	(34,552)	(35,994)
Underwriting income (loss)	(20,634)	(69,443)
Net investment income	11,352	11,942
Net realized and unrealized gains (losses)	(54,086)	20,658
Fees and commission income	0	0
Other income	85	60
Corporate expenses	(574)	0
Interest income (expense)	(447)	(475)
Net foreign exchange gains (losses)	(590)	(594)
EARNINGS (LOSS) BEFORE INCOME TAXES	(64,894)	(37,852)
Income tax benefit (expense)	1,615	(1,259)
Earnings from equity method investments	0	188
NET EARNINGS (LOSS)		(38,923)
Net loss attributable to noncontrolling interest	26,767	7,922
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR	(36,512)	(31,001)
Dividends on preferred shares	0	0
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	(36,512)	(31,001)
Other
Segment Reporting Information [Line Items]
Gross premiums written	(3,885)	864
Net premiums written	(3,221)	845
Net premiums earned	3,337	6,598
Net incurred losses and LAE	(2,482)	(4,956)
Life and Annuity Policy Benefits		(96)
Acquisition costs	(83)	(232)
Operating expenses	0	0
Underwriting income (loss)	772	1,314
Net investment income	(2,488)	(1,685)
Net realized and unrealized gains (losses)	0	1,034
Fees and commission income	0	0
Other income	(1,971)	212
Corporate expenses	(16,040)	(8,697)
Interest income (expense)	2,931	1,555
Net foreign exchange gains (losses)	0	1
EARNINGS (LOSS) BEFORE INCOME TAXES	(16,796)	(6,266)
Income tax benefit (expense)	0	(85)
Earnings from equity method investments	0	0
NET EARNINGS (LOSS)		(6,351)	$ (16,796)
Net loss attributable to noncontrolling interest	0	0
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR	(16,796)	(6,351)
Dividends on preferred shares	(8,925)	(9,139)
NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$ (25,721)	$ (15,490)

Segment Information - Summary of Company's Assets by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 19,131,509	$ 19,363,315
Operating Segments \| Non-life Run-off
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	15,438,588	15,775,409
Operating Segments \| Atrium
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	590,805	580,405
Operating Segments \| StarStone
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	3,627,036	3,522,353
Other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ (524,920)	$ (514,852)

Label	Element	Value
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (6,148,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 0

Investments - Credit Ratings (Details) $ in Thousands	3 Months Ended
Investments - Credit Ratings (Details) $ in Thousands	Mar. 31, 2020 USD ($)
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 9,177,658
Fair Value	9,023,770
Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 349,924
Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	100.00%
Marketable Securities \| Credit Rating Concentration Risk \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	3.90%
AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 2,384,570
AAA Rated \| Marketable Securities \| Credit Rating Concentration Risk \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	26.40%
AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,101,376
AA Rated \| Marketable Securities \| Credit Rating Concentration Risk \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	12.20%
A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 3,223,772
A Rated \| Marketable Securities \| Credit Rating Concentration Risk \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	35.70%
BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,858,346
BBB Rated \| Marketable Securities \| Credit Rating Concentration Risk \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	20.60%
Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 105,782
Not Rated \| Marketable Securities \| Credit Rating Concentration Risk
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	1.20%
U.S. government and agency
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 488,708
Fair Value	519,933
U.S. government and agency \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 0
U.S. government and agency \| Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	5.80%
U.S. government and agency \| AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 519,933
U.S. government and agency \| AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
U.S. government and agency \| A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
U.S. government and agency \| BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
U.S. government and agency \| Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
U.K. government
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	100,716
Fair Value	100,005
U.K. government \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 0
U.K. government \| Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	1.10%
U.K. government \| AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 538
U.K. government \| AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	99,467
U.K. government \| A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
U.K. government \| BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
U.K. government \| Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
Other government
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	618,746
Fair Value	604,014
Other government \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 20,478
Other government \| Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	6.70%
Other government \| AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 268,626
Other government \| AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	136,721
Other government \| A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	63,097
Other government \| BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	111,636
Other government \| Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	3,456
Corporate
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	5,622,480
Fair Value	5,538,691
Corporate \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 277,738
Corporate \| Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	61.30%
Corporate \| AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 140,194
Corporate \| AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	602,836
Corporate \| A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	2,908,118
Corporate \| BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	1,594,296
Corporate \| Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	15,509
Municipal
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	155,587
Fair Value	164,830
Municipal \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 0
Municipal \| Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	1.80%
Municipal \| AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 16,425
Municipal \| AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	77,511
Municipal \| A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	49,068
Municipal \| BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	21,826
Municipal \| Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
Residential mortgage-backed
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	466,964
Fair Value	467,918
Residential mortgage-backed \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 35,489
Residential mortgage-backed \| Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	5.20%
Residential mortgage-backed \| AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 395,148
Residential mortgage-backed \| AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	26,892
Residential mortgage-backed \| A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	3,085
Residential mortgage-backed \| BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	1,602
Residential mortgage-backed \| Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	5,702
Commercial mortgage-backed
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	894,859
Fair Value	873,504
Commercial mortgage-backed \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 5,867
Commercial mortgage-backed \| Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	9.70%
Commercial mortgage-backed \| AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 621,883
Commercial mortgage-backed \| AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	93,167
Commercial mortgage-backed \| A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	78,379
Commercial mortgage-backed \| BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	57,187
Commercial mortgage-backed \| Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	17,021
Asset-backed
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	829,598
Fair Value	754,875
Asset-backed \| Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 10,352
Asset-backed \| Marketable Securities \| Portfolio Concentration Risk \| Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	8.40%
Asset-backed \| AAA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 421,823
Asset-backed \| AA Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	64,782
Asset-backed \| A Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	122,025
Asset-backed \| BBB Rated \| Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	71,799
Asset-backed \| Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 64,094

Investments - Other Investments at Fair Value by Notice Period (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Other investments, at fair value	$ 2,326,984	$ 2,524,420
Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	1,055,448	1,121,904
Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	463,717	481,039
Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	320,046	410,149
Private equities and private equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	309,219	329,885
CLO equities
Schedule of Investments [Line Items]
Other investments, at fair value	83,740	87,555
CLO equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	66,938	87,509
Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value	20,473	0
Other
Schedule of Investments [Line Items]
Other investments, at fair value	7,403	6,379
Less than 1 Year
Schedule of Investments [Line Items]
Other investments, at fair value	1,238,290
Less than 1 Year \| Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	325,882
Less than 1 Year \| Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	460,684
Less than 1 Year \| Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	320,046
Less than 1 Year \| Private equities and private equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
Less than 1 Year \| CLO equities
Schedule of Investments [Line Items]
Other investments, at fair value	83,740
Less than 1 Year \| CLO equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	47,938
Less than 1 Year \| Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value		0
Less than 1 Year \| Other
Schedule of Investments [Line Items]
Other investments, at fair value	0
1-2 years
Schedule of Investments [Line Items]
Other investments, at fair value	576,616
1-2 years \| Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	576,616
1-2 years \| Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
1-2 years \| Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
1-2 years \| Private equities and private equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
1-2 years \| CLO equities
Schedule of Investments [Line Items]
Other investments, at fair value	0
1-2 years \| CLO equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
1-2 years \| Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value		0
1-2 years \| Other
Schedule of Investments [Line Items]
Other investments, at fair value	0
2-3 years
Schedule of Investments [Line Items]
Other investments, at fair value	19,000
2-3 years \| Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
2-3 years \| Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
2-3 years \| Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
2-3 years \| Private equities and private equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
2-3 years \| CLO equities
Schedule of Investments [Line Items]
Other investments, at fair value	0
2-3 years \| CLO equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	19,000
2-3 years \| Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value		0
2-3 years \| Other
Schedule of Investments [Line Items]
Other investments, at fair value	0
More than 3 years
Schedule of Investments [Line Items]
Other investments, at fair value	102,600
More than 3 years \| Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	102,600
More than 3 years \| Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
More than 3 years \| Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
More than 3 years \| Private equities and private equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
More than 3 years \| CLO equities
Schedule of Investments [Line Items]
Other investments, at fair value	0
More than 3 years \| CLO equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
More than 3 years \| Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value		0
More than 3 years \| Other
Schedule of Investments [Line Items]
Other investments, at fair value	0
Not Eligible/ Restricted
Schedule of Investments [Line Items]
Other investments, at fair value	390,478
Not Eligible/ Restricted \| Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	50,350
Not Eligible/ Restricted \| Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	3,033
Not Eligible/ Restricted \| Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
Not Eligible/ Restricted \| Private equities and private equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	309,219
Not Eligible/ Restricted \| CLO equities
Schedule of Investments [Line Items]
Other investments, at fair value	0
Not Eligible/ Restricted \| CLO equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
Not Eligible/ Restricted \| Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value		$ 20,473
Not Eligible/ Restricted \| Other
Schedule of Investments [Line Items]
Other investments, at fair value	$ 7,403