Enstar Group Limited (ESGR) 10-Q 6 Nov 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Nov. 04, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 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	Q3
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		18,564,268
Nonvoting Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,509,682

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
ASSETS
Available-for-sale, at fair value	$ 3,161,647	$ 1,666,387
Funds held - directly managed	1,066,639	1,187,552
Equities, at fair value	653,159	726,721
Other investments, at fair value	3,704,870	2,518,031
Equity method investments	516,795	326,277
Total investments (Note 5 and Note 11)	14,109,885	12,619,793
Cash and cash equivalents	640,601	624,472
Restricted cash and cash equivalents	556,721	346,877
Premiums receivable	450,977	491,511
Deferred tax assets (Note 19)	157,827	155,793
Reinsurance balances recoverable on paid and unpaid losses (net of allowance: 2020 — $135,117) (Note 7)	1,338,495	1,485,616
Reinsurance balances recoverable on paid and unpaid losses, at fair value (Note 7 and Note 11)	543,161	695,518
Insurance balances recoverable (net of allowance: 2020 — $5,907) (Note 10)	365,288	448,855
Funds held by reinsured companies	657,490	475,732
Deferred acquisition costs	52,899	116,513
Goodwill and intangible assets (Note 13)	62,959	191,568
Other assets	677,797	699,081
Assets held-for-sale (Note 4)	2,156,488	1,474,770
TOTAL ASSETS	21,770,588	19,826,099
LIABILITIES
Losses and loss adjustment expenses (Note 9)	7,878,206	7,247,282
Losses and loss adjustment expenses, at fair value (Note 9 and Note 11)	2,422,678	2,621,122
Defendant asbestos and environmental liabilities (Note 10)	754,037	847,685
Unearned premiums	335,336	533,692
Insurance and reinsurance balances payable	581,615	420,546
Deferred tax liabilities (Note 19)	6,493	16,074
Debt obligations (Note 14)	1,447,908	1,191,207
Other liabilities	478,888	444,818
Liabilities held-for-sale (Note 4)	1,653,343	1,208,531
TOTAL LIABILITIES	15,558,504	14,530,957
COMMITMENTS AND CONTINGENCIES (Note 21)
REDEEMABLE NONCONTROLLING INTEREST (Note 15)	376,731	438,791
SHAREHOLDERS’ EQUITY (Note 16)
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	1,832,130	1,836,778
Accumulated other comprehensive income	61,873	7,171
Retained earnings	3,816,548	2,887,892
Total Enstar Shareholders’ Equity	5,820,885	4,842,183
Noncontrolling interest (Note 15)	14,468	14,168
TOTAL SHAREHOLDERS’ EQUITY	5,835,353	4,856,351
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTEREST AND SHAREHOLDERS’ EQUITY	$ 21,770,588	$ 19,826,099
Treasury shares, preferred at cost (in shares)	388,571	388,571
Voting Ordinary shares (issued and outstanding 2020: 18,559,762; 2019: 18,001,823)
SHAREHOLDERS’ EQUITY (Note 16)
Ordinary shares	$ 18,560	$ 18,002
Non-voting convertible ordinary Series C Shares (issued and outstanding 2020 and 2019: 2,599,672)
SHAREHOLDERS’ EQUITY (Note 16)
Ordinary shares	2,600	2,600
Non-voting convertible ordinary Series E Shares (issued and outstanding 2020 and 2019: 910,010)
SHAREHOLDERS’ EQUITY (Note 16)
Ordinary shares	910	910
Series C Preferred Shares (issued and held in treasury 2020 and 2019: 388,571)
SHAREHOLDERS’ EQUITY (Note 16)
Preferred Shares	$ 389	$ 389
Treasury shares, preferred at cost (in shares)	388,571	388,571
Series D Preferred Shares (issued and outstanding 2020 and 2019: 16,000)
SHAREHOLDERS’ EQUITY (Note 16)
Preferred Shares	$ 400,000	$ 400,000
Series E Preferred Shares (issued and outstanding 2020 and 2019: 4,400)
SHAREHOLDERS’ EQUITY (Note 16)
Preferred Shares	110,000	110,000
Short-term investments, AFS, at fair value
ASSETS
Trading, at fair value	7,133	51,490
Available-for-sale, at fair value	278,175	128,335
Fixed maturity investments
ASSETS
Trading, at fair value	4,999,642	6,143,335
Available-for-sale, at fair value	$ 2,883,472	$ 1,538,052

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
ASSETS
Investments, available-for-sale, at fair value, amortized cost	$ 3,115,580	$ 1,666,126
Investments, allowance for credit losses	912	0
Reinsurance recoverable, allowance for credit loss	135,117
Insurance balance recoverable, allowance for credit loss	$ 5,907	$ 3,818
SHAREHOLDERS’ EQUITY
Common Stock, Par or Stated Value Per Share	$ 1	$ 1
Ordinary shares issued (in shares)	22,069,444	21,511,505
Ordinary shares outstanding (in shares)	22,069,444	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)	18,559,762	18,001,823
Ordinary shares outstanding (in shares)	18,559,762	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
Treasury shares, preferred at cost (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, AFS, at fair value
ASSETS
Investments, available-for-sale, at fair value, amortized cost	$ 278,221	$ 128,311
Investments, allowance for credit losses	0
Fixed maturity investments
ASSETS
Investments, available-for-sale, at fair value, amortized cost	2,837,359	$ 1,537,815
Investments, allowance for credit losses	$ 912

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
INCOME
Net premiums earned	$ 161,724	$ 175,802	$ 463,946	$ 618,711
Fees and commission income	10,787	6,437	28,325	18,931
Net investment income	72,130	81,502	241,287	231,424
Net realized and unrealized gains	500,005	145,060	838,552	858,489
Other income	48,404	822	67,761	15,368
Total income	793,050	409,623	1,639,871	1,742,923
EXPENSES
Net incurred losses and loss adjustment expenses	109,686	163,258	339,678	566,111
Acquisition costs	37,708	33,310	132,818	162,192
General and administrative expenses	115,828	97,365	359,086	296,304
Interest expense	15,003	14,950	42,436	39,022
Net foreign exchange (gains) losses	8,156	(13,665)	1,375	(20,097)
Total expenses	286,381	295,218	875,393	1,043,532
EARNINGS BEFORE INCOME TAXES	506,669	114,405	764,478	699,391
Income tax expense	(13,915)	(13,465)	(25,295)	(25,265)
Earnings from equity method investments	149,065	17,703	152,725	44,188
NET EARNINGS FROM CONTINUING OPERATIONS	641,819	118,643	891,908	718,314
NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	4,031	7,916	810	12,041
NET EARNINGS	645,850	126,559	892,718	730,355
Net loss (earnings) attributable to noncontrolling interest	(21,912)	109	30,802	4,970
NET EARNINGS ATTRIBUTABLE TO ENSTAR	623,938	126,668	923,520	735,325
Dividends on preferred shares	(8,925)	(8,925)	(26,775)	(26,989)
NET EARNINGS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$ 615,013	$ 117,743	$ 896,745	$ 708,336
Basic:
Net earnings from continuing operations (in dollars per share)	$ 28.39	$ 5.26	$ 41.56	$ 32.65
Net earnings from discontinued operations (in dollars per share)	0.11	0.22	0.02	0.33
Net earnings per ordinary share (in dollars per share)	28.50	5.48	41.58	32.98
Diluted:
Net earnings from continuing operations (in dollars per share)	28.13	5.21	41.12	32.25
Net earnings from discontinued operations (in dollars per share)	0.11	0.21	0.02	0.33
Net earnings per ordinary share (in dollars per share)	$ 28.24	$ 5.42	$ 41.14	$ 32.58
Weighted average ordinary shares outstanding:
Basic (in shares)	21,578,106	21,488,216	21,564,447	21,476,586
Diluted (in shares)	21,778,729	21,720,497	21,799,627	21,741,499

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
NET EARNINGS	$ 645,850	$ 126,559	$ 892,718	$ 730,355
Other comprehensive income (loss), net of income taxes:
Unrealized gains (losses) on fixed income available-for-sale investments arising during the period	21,198	(267)	74,969	4,640
Reclassification adjustment for change in allowance for credit losses recognized in net earnings	(2,379)	0	71	0
Reclassification adjustment for net realized losses included in net earnings	(9,488)	(34)	(13,498)	(4,191)
Unrealized gains (losses) arising during the period, net of reclassification adjustments	9,331	(301)	61,542	449
Cumulative currency translation adjustment	1,891	(2,551)	0	(4,390)
Increase in defined benefit pension liability	0	(952)	0	(952)
Total other comprehensive income (loss)	11,222	(3,804)	61,542	(4,893)
Comprehensive income	657,072	122,755	954,260	725,462
Comprehensive (income) loss attributable to noncontrolling interest	(22,546)	206	23,962	4,912
COMPREHENSIVE INCOME ATTRIBUTABLE TO ENSTAR	$ 634,526	$ 122,961	$ 978,222	$ 730,374

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Ordinary SharesVoting Ordinary Shares	Ordinary SharesSeries C Non-Voting Convertible Ordinary Shares	Ordinary SharesSeries E Non-Voting Convertible Ordinary Shares	Preferred StockSeries C Preferred Shares	Preferred StockSeries D Preferred Stock	Preferred StockSeries 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	Retained EarningsCumulative effect of change in accounting principle	Noncontrolling Interest (excludes Redeemable Noncontrolling Interest)
Balance, beginning of period at Dec. 31, 2018		$ 17,950	$ 2,600	$ 910	$ 389	$ 400,000	$ 110,000	$ (421,559)	$ 0	$ 1,804,664	$ 10,440	$ 10,986	$ (987)	$ 441	$ 1,976,539	$ 0	$ 12,056
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares		31							0	1,497
Shares repurchased		0								0
Amortization of share-based compensation										24,346
Change in other comprehensive income (loss)	$ (4,893)											(4,399)		400
Change in defined benefit pension liability	(952)												(951)
Net earnings	708,336														730,355
Net loss (earnings) attributable to noncontrolling interest	4,970														4,970		681
Dividend on preferred shares															(26,989)
Change in redemption value of redeemable noncontrolling interests															6,607
Purchase of noncontrolling shareholders' interest in subsidiaries																	(47)
Balance, end of period at Sep. 30, 2019	4,650,490	17,981	2,600	910	389	400,000	110,000	(421,559)	0	1,830,507	5,490	6,587	(1,938)	841	2,691,482		12,690
Balance, beginning of period at Jun. 30, 2019		17,975	2,600	910	389	400,000	110,000	(421,559)	0	1,822,202	9,196	9,147	(987)	1,036	2,573,117	0	12,609
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares		6							0	576
Shares repurchased		0								0
Amortization of share-based compensation										7,729
Change in other comprehensive income (loss)	(3,804)											(2,560)		(195)
Change in defined benefit pension liability	(952)												(951)
Net earnings	117,743														126,559
Net loss (earnings) attributable to noncontrolling interest	109														109		81
Dividend on preferred shares															(8,925)
Change in redemption value of redeemable noncontrolling interests															622
Purchase of noncontrolling shareholders' interest in subsidiaries																	0
Balance, end of period at Sep. 30, 2019	4,650,490	17,981	2,600	910	389	400,000	110,000	(421,559)	0	1,830,507	5,490	6,587	(1,938)	841	2,691,482		12,690
Balance, beginning of period at Dec. 31, 2019	4,856,351	18,002	2,600	910	389	400,000	110,000	(421,559)	0	1,836,778	7,171	8,548	(945)	(432)	2,887,892	(6,148)	14,168
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares		732							(566)	(857)
Shares repurchased		(174)								(25,215)
Amortization of share-based compensation										21,424
Change in other comprehensive income (loss)	61,542											753		53,949
Change in defined benefit pension liability	0												0
Net earnings	896,745														892,718
Net loss (earnings) attributable to noncontrolling interest	30,802														30,802		300
Dividend on preferred shares															(26,775)
Change in redemption value of redeemable noncontrolling interests															38,059
Purchase of noncontrolling shareholders' interest in subsidiaries																	0
Balance, end of period at Sep. 30, 2020	5,835,353	18,560	2,600	910	389	400,000	110,000	(421,559)	(566)	1,832,130	61,873	9,301	(945)	53,517	3,816,548		14,468
Balance, beginning of period at Jun. 30, 2020		18,635	2,600	910	389	400,000	110,000	(421,559)	(566)	1,835,115	51,285	6,824	(945)	45,406	3,190,104	$ 0	13,553
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares		6							0	503
Shares repurchased		(81)								(12,782)
Amortization of share-based compensation										9,294
Change in other comprehensive income (loss)	11,222											2,477		8,111
Change in defined benefit pension liability	0												0
Net earnings	615,013														645,850
Net loss (earnings) attributable to noncontrolling interest	(21,912)														(21,912)		915
Dividend on preferred shares															(8,925)
Change in redemption value of redeemable noncontrolling interests															11,431
Purchase of noncontrolling shareholders' interest in subsidiaries																	0
Balance, end of period at Sep. 30, 2020	$ 5,835,353	$ 18,560	$ 2,600	$ 910	$ 389	$ 400,000	$ 110,000	$ (421,559)	$ (566)	$ 1,832,130	$ 61,873	$ 9,301	$ (945)	$ 53,517	$ 3,816,548		$ 14,468

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		7 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
OPERATING ACTIVITIES:
Net earnings	$ 645,850	$ 126,559		$ 892,718	$ 730,355
Net earnings from discontinued operations, net of income taxes	(4,031)	(7,916)		(810)	(12,041)
Adjustments to reconcile net earnings to cash flows provided by operating activities:
Realized gains on sale of investments				(114,894)	(49,243)
Unrealized gains on investments				(723,658)	(809,246)
Depreciation and other amortization				42,210	23,652
Earnings from equity method investments	(149,065)	(17,703)		(152,725)	(44,188)
Sales and maturities of trading securities				2,778,993	4,133,200
Purchases of trading securities				(1,531,190)	(3,876,661)
Other non-cash items				20,847	26,098
Changes in:
Reinsurance balances recoverable on paid and unpaid losses				266,289	(207,579)
Funds held by reinsured companies				(211,850)	(48,814)
Losses and loss adjustment expenses				697,516	474,707
Defendant asbestos and environmental liabilities				(93,648)	(22,957)
Insurance and reinsurance balances payable				172,358	38,382
Unearned premiums				(106,748)	(21,999)
Premiums receivable				(18,950)	195,751
Other operating assets and liabilities				187,572	(99,849)
Net cash flows provided by operating activities				2,104,030	429,568
INVESTING ACTIVITIES:
Sales and maturities of available-for-sale securities				1,673,800	100,154
Purchase of available-for-sale securities				(3,125,184)	(363,221)
Purchase of other investments				(812,586)	(731,588)
Proceeds from other investments				282,330	460,554
Purchase of equity method investments				(33,000)	(38,403)
Other investing activities				3,606	(1,204)
Net cash flows used in investing activities				(2,011,034)	(573,708)
FINANCING ACTIVITIES:
Dividends on preferred shares				(26,775)	(26,989)
Dividends paid to redeemable noncontrolling interest				0	(11,556)
Purchase of noncontrolling shareholders' interest in subsidiaries				0	(47)
Repurchase of shares			$ (25,400)	(25,390)	0
Receipt of loans				858,788	1,070,808
Repayment of loans				(604,000)	(722,574)
Net cash flows provided by financing activities				202,623	309,642
Net cash flows provided by operating activities				114,024	210,666
Net cash flows used in investing activities				(134,759)	(5,332)
Net cash flows from discontinued operations				(20,735)	205,334
EFFECT OF EXCHANGE RATE CHANGES ON FOREIGN CURRENCY CASH AND CASH EQUIVALENTS				1,727	(12,507)
NET INCREASE IN CASH AND CASH EQUIVALENTS				276,611	358,329
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD				971,349	901,996	$ 901,996
CASH AND CASH EQUIVALENTS, END OF PERIOD	1,197,322	1,054,992	1,197,322	1,197,322	1,054,992	971,349
NET CHANGE IN CASH OF BUSINESSES HELD FOR SALE				(50,638)	(205,333)
Supplemental Cash Flow Information:
Income taxes paid, net of refunds				15,870	(271)
Interest paid				37,275	33,742
Reconciliation to Consolidated Balance Sheets:
Cash and cash equivalents							$ 640,601	$ 624,472	$ 557,677
Restricted cash and cash equivalents							556,721	346,877	497,315
Cash, cash equivalents and restricted cash	$ 1,197,322	$ 1,054,992	$ 1,197,322	$ 1,197,322	$ 1,054,992	$ 901,996	$ 1,197,322	$ 971,349	$ 1,054,992

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 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 as described in further detail in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations." 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 2020-04 – Reference Rate Reform In March 2020, the Financial Accounting Standards Board ("FASB") issued ASU 2020-04 – Reference Rate Reform – Facilitation of the Effects of Reference Rate Reform on Financial Reporting , which is codified in Accounting Standards Codification ("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 guidance, 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 this guidance must be applied prospectively for all eligible contract modifications. The ASU was effective upon issuance and can be applied through to December 31, 2022. We adopted the ASU upon its issuance and as we transition from LIBOR to alternative reference rates, we will 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. The adoption of this standard did not have any impact on our consolidated financial statements and disclosures. ASU 2020-03 – Codification Improvements to Financial Instruments In March 2020, the 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 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 • 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, we are yet to adopt the following accounting pronouncements that the FASB issued during and subsequent to the nine months ended September 30, 2020. ASU 2020-09 – Amendments to SEC Paragraphs Pursuant to SEC Release No. 33-10762 In October 2020, the FASB issued ASU 2020-09, which amends and supersedes various SEC paragraphs in ASC 270, ASC 460, ASC 470 and ASC 505 pursuant to the issuance of the SEC's Release No. 33-10762. Through Release No. 33-10762, the SEC made amendments to the financial disclosure requirements in Regulation S-X for guarantors and issuers of guaranteed securities registered or being registered, and issuers’ affiliates whose securities collateralize securities registered or being registered, to improve those requirements for both investors and registrants. The changes made by the SEC are intended to provide investors with material information given the specific facts and circumstances, make the disclosures easier to understand, and reduce the costs and burdens to registrants. In addition, by reducing the costs and burdens of compliance, issuers may be encouraged to offer guaranteed or collateralized securities on a registered basis, thereby affording investors protection they may not be provided in offerings conducted on an unregistered basis. Finally, by making it less burdensome and less costly for issuers to include guarantees or pledges of affiliate securities as collateral when they structure debt offerings, the revisions may increase the number of registered offerings that include these credit enhancements, which could result in a lower cost of capital and an increased level of investor protection. The amended rules in Release No. 33-10762 are effective on January 4, 2021 although early compliance is permitted, hence we elected early compliance with the new rules. Because the amendments made by the FASB in this ASU are to ensure alignment of the relevant SEC paragraphs in ASC 270, ASC 460, ASC 470 and ASC 505 with the amended rules in Release No. 33-10762, the amendments made by the FASB to these SEC paragraphs will not have a material impact on our disclosures, since we already elected early compliance with the amended rules in Release No. 33-10762. ASU 2020-08 – Codification Improvements to Subtopic 310-20 - Receivables - Nonrefundable Fees and Other Costs In October 2020, the FASB issued ASU 2020-08 to clarify that an entity should re-evaluate whether a callable debt security is within the scope of ASC 310-20-35-33 during each reporting period. All entities are required to apply the amendments in this ASU on a prospective basis as of the beginning of the period of adoption for existing or newly purchased callable debt securities. The amendments in this ASU are effective for interim and annual reporting periods beginning after December 15, 2020, and early adoption is not permitted. We do not expect the adoption of this guidance to have a material impact on our consolidated financial statements and the related disclosures. ASU 2020-06 – Accounting for Convertible Instruments and Contracts in an Entity's Own Equity In August 2020, the FASB issued ASU 2020-06, which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts in an entity's own equity. For convertible instruments, the ASU eliminates two of the three accounting models in ASC 470-20 that require separate accounting for embedded conversion features. The ASU also simplifies an issuer's application of the derivatives scope exception in ASC 815-40 for contracts in its own equity and removes some of the conditions that preclude a freestanding contract from being classified in equity, thereby allowing more of such contracts to qualify for equity classification. The amendments in this ASU are effective for interim and annual reporting periods beginning after December 15, 2021 and, although early adoption is permitted, the amendments may not be adopted earlier than during interim and annual reporting periods beginning after December 15, 2020. We do not expect the adoption of this guidance to have a material impact on our consolidated financial statements and the related disclosures.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Acquisitions	2. ACQUISITIONS Morse TEC 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

Significant New Business	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
SIGNIFICANT NEW BUSINESS	3. SIGNIFICANT NEW BUSINESS Hannover Re On August 6, 2020, we completed a novation agreement with Hannover Reück SE and an affiliate (“Hannover Re”), pursuant to which we assumed certain legacy asbestos, environmental and workers' compensation exposures. In the transaction, we assumed loss reserves of $209.7 million in exchange for net novation consideration of $182.5 million. We elected the fair value option for this novation agreement and recorded an initial fair value adjustment of $27.2 million on the assumed loss reserves. Refer to Note 11 - "Fair Value Measurements" for a description of the fair value process and the assumptions made. Munich Re On July 1, 2020, we completed a business transfer transaction with Great Lakes Insurance SE and HSB Engineering Insurance Limited, both subsidiaries of Munich Reinsurance Company ("Munich Re"), pursuant to which we assumed certain portfolios from their Australian branches. In the transaction, we assumed net loss reserves of AUD$142.2 million ($98.0 million), which primarily relate to public and products liability, property and engineering exposures, in exchange for net consideration of an equal amount. AXA Group On June 1, 2020, we completed a loss portfolio transfer reinsurance agreement with AXA XL, a division of AXA SA, to reinsure specified legacy construction general liability multi-year policies. We assumed gross loss reserves of $179.7 million, which was equal to the net reinsurance premium consideration received in the transaction. In addition, we provided additional collateral of $24.5 million to support our obligations to AXA XL per the terms of the reinsurance agreement. Effective October 1, 2020, we have ceded 10% of this transaction to Enhanzed Reinsurance Ltd. ("Enhanzed Re"), in which we have an investment, on the same terms and conditions as those received by Enstar. Aspen On June 1, 2020, we completed an adverse development cover reinsurance transaction with Aspen Insurance Holdings Limited. In the transaction, we assumed $781.6 million of gross reserves for losses incurred on or prior to December 31, 2019 on a diversified mix of property, liability and specialty lines of business across the U.S., U.K. and Europe, in exchange for reinsurance premium consideration of $770.0 million and recorded a deferred charge asset of $11.7 million. Pursuant to the agreement, we 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. 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”). In the transaction, in exchange for premium consideration of $465.0 million, we reinsured legacy automobile business underwritten by Zurich between October 1, 2015 and September 30, 2018 and which previously had been reinsured by Lyft’s wholly owned subsidiary, Pacific Valley Insurance Company ("PVIC"). Under a separate but related agreement, PVIC provides retrocession reinsurance coverage to us on the Lyft business reinsured in excess of an $816.0 million limit. The transaction was effective on March 31, 2020.

Divestitures, Held-For-Sale Bus

Divestitures, Held-For-Sale Businesses and Discontinued Operations	9 Months Ended
	Sep. 30, 2020
Discontinued Operations and Disposal Groups [Abstract]
DIVESTITURES, HELD-FOR-SALE BUSINESSES AND DISCONTINUED OPERATIONS	4. DIVESTITURES, HELD-FOR-SALE BUSINESSES AND DISCONTINUED OPERATIONS Atrium Exchange Transaction On August 13, 2020, we announced an exchange transaction with Trident V, L.P., Trident V Parallel Fund, L.P. and Trident V Professionals Fund, L.P. (collectively, the "Trident V Funds") managed by Stone Point Capital LLC ("Stone Point"). As part of the exchange, we entered into a recapitalization agreement with the Trident V Funds, Dowling Capital Partners I, L.P. and Capital City Partners LLC (collectively, the "Dowling Funds"), North Bay Holdings Limited ("North Bay"), and StarStone Specialty Holdings Limited ("SSHL"). Enstar currently owns an indirect 59.0% interest in North Bay and the Trident V Funds and the Dowling Funds currently own 39.3% and 1.7%, respectively. North Bay owns 100.0% of SSHL, the holding company for the StarStone group, which includes StarStone's U.S. operations, including StarStone U.S. Holdings, Inc. and its subsidiaries ("StarStone U.S.") and its non-U.S. operations ("StarStone International"). North Bay also owns approximately 92.1% of Northshore Holdings Limited ("Northshore"), the holding company that owns Atrium Underwriting Group Limited and its subsidiaries (collectively, "Atrium") and Arden Reinsurance Company Ltd. ("Arden"). The remaining share ownership of Northshore is held on behalf of certain Atrium employees. Pursuant to the terms of the recapitalization agreement, we agreed to exchange a portion of our indirect interest in Northshore for all of the Trident V Funds’ indirect interest in StarStone U.S. (the “Exchange Transaction”). The Exchange Transaction is conditioned on the closing of the sale of StarStone U.S. to Core Specialty Insurance Holdings, Inc. ("Core Specialty"), as described further below, and is subject to regulatory approval and other closing conditions. The exchange transaction is expected to close in the first quarter of 2021. Upon completion of the sale of StarStone U.S. to Core Specialty and the Exchange Transaction with the Trident V Funds, we expect to own indirectly approximately 26.1% of Core Specialty, which will then own StarStone U.S., and approximately 11.0% of Northshore, which will continue to own Atrium and Arden. Our ultimate ownership in Northshore at the closing of the Exchange Transaction may vary based on, among other things, the final valuation of StarStone U.S. in its sale to Core Specialty and if, and to the extent, certain employees of Atrium elect to defer the payout of certain long-term equity awards. Upon the closing of the Exchange Transaction, the Trident V Funds will not own any interest in Core Specialty and are expected to own approximately 80.0% of Northshore, and the Dowling Funds will own approximately 0.5% of Core Specialty and retain their approximately 1.6% interest in Northshore. The Exchange Transaction will have no impact on the ultimate ownership of SSHL, which will own StarStone International, with us, the Trident V Funds and the Dowling Funds retaining our and their current ownership interests in SSHL of 59.0%, 39.3% and 1.7%, respectively. Upon completion of the Exchange Transaction, our investment in Northshore will be accounted for as a privately held equity investment and will be carried at fair value. We have classified the assets and liabilities of Northshore as held-for-sale as of September 30, 2020. The impending disposal of Enstar's majority equity interest in Northshore does not represent a strategic shift that will have a major effect on our operations and financial results, and therefore the disposal is not reported as a discontinued operation during the current or prior periods. The following table summarizes the components of Northshore's assets and liabilities held-for-sale on our consolidated balance sheets as of September 30, 2020: September 30, 2020 ASSETS Short-term investments, available-for-sale, at fair value $ 1,852 Fixed maturities, trading, at fair value 154,325 Fixed maturities, available-for-sale, at fair value 9,252 Equities, at fair value 18,120 Other investments, at fair value 87,795 Total investments 271,344 Cash and cash equivalents 61,221 Restricted cash and cash equivalents 10,152 Premiums receivable 59,484 Deferred tax assets 97 Reinsurance balances recoverable on paid and unpaid losses 30,673 Funds held by reinsured companies 30,092 Deferred acquisition costs 24,522 Goodwill and intangible assets 115,085 Other assets 48,308 TOTAL ASSETS HELD-FOR-SALE $ 650,978 LIABILITIES Losses and loss adjustment expenses $ 248,532 Unearned premiums 91,608 Insurance and reinsurance balances payable 10,916 Deferred tax liabilities 14,010 Other liabilities 66,020 TOTAL LIABILITIES HELD-FOR-SALE $ 431,086 NET ASSETS HELD-FOR-SALE $ 219,892 As of September 30, 2020, included in the table above were restricted investments of $117.6 million. The unrealized gains (losses) on AFS investments in accumulated other comprehensive income (loss) ("AOCI"), a component of shareholders' equity, included ($0.3) million as at September 30, 2020 related to Northshore. Upon completion of the Exchange Transaction, the balance at closing will be included in earnings as a component of the gain on sale. Recapitalization of StarStone U.S. On June 10, 2020, we announced an agreement to recapitalize StarStone U.S. and appoint a new management team and Board. As part of the recapitalization, we entered into a definitive agreement to sell StarStone U.S. to Core Specialty, a newly formed entity with equity backing from funds managed by SkyKnight Capital, L.P., Dragoneer Investment Group and Aquiline Capital Partners LLC. We currently have a 59.0% interest in StarStone U.S. The purchase price will be based on a $30.0 million premium to the GAAP tangible book value of StarStone U.S. to be determined on the month end prior to the closing date and will consist of $235.0 million of common shares of Core Specialty and cash. The $235.0 million of common shares of Core Specialty is expected to represent an estimated 26.1% interest in Core Specialty after certain co-investments and management equity awards. Our investment in Core Specialty will be accounted for as an equity method investment. Given the proposed transaction, we have classified the StarStone U.S. results as discontinued operations for the periods presented. In connection with the sale, one of our Non-life Run-off subsidiaries will enter into a loss portfolio transfer reinsurance agreement with StarStone U.S. pursuant to which we will reinsure all of the net loss reserves of StarStone U.S. in respect of premium earned prior to the calendar month end prior to the closing date. We will receive a reinsurance premium equal to the assumed reserves, plus approximately $16.0 million. The reinsurance agreement will contain an aggregate limit on our liability equal to $130.0 million in excess of the assumed reserves, and our subsidiary's obligations under the reinsurance agreement will be guaranteed by Enstar. The closing of the transaction is subject to regulatory approvals and other closing conditions and is expected to occur in the fourth quarter of 2020. StarStone U.S. comprises a substantial portion of the StarStone segment. We have classified the assets and liabilities of StarStone U.S. as held-for-sale as of September 30, 2020. The following table summarizes the components of StarStone U.S.'s assets and liabilities held-for-sale on our consolidated balance sheets as of September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 (1) ASSETS Fixed maturities, trading, at fair value $ 140,124 $ 202,994 Fixed maturities, available-for-sale, at fair value 525,842 375,337 Equities, at fair value 5,494 3,000 Other investments, at fair value 6,864 6,389 Total investments 678,324 587,720 Cash and cash equivalents 54,303 78,613 Restricted cash and cash equivalents 9,390 5,815 Premiums receivable 105,339 99,367 Deferred tax assets 14,890 15,191 Reinsurance balances recoverable on paid and unpaid losses 477,739 530,604 Funds held by reinsured companies 29,678 35,861 Deferred acquisition costs 32,071 36,992 Goodwill and intangible assets 24,900 24,900 Other assets 78,876 59,707 TOTAL ASSETS HELD-FOR-SALE $ 1,505,510 $ 1,474,770 LIABILITIES Losses and loss adjustment expenses $ 830,456 $ 836,761 Unearned premiums 217,375 218,166 Insurance and reinsurance balances payable 49,822 22,453 Other liabilities 124,604 131,151 TOTAL LIABILITIES HELD-FOR-SALE $ 1,222,257 $ 1,208,531 NET ASSETS HELD-FOR-SALE $ 283,253 $ 266,239 (1) In accordance with U.S. GAAP, the assets and liabilities of StarStone U.S. as of December 31, 2019 have been reclassified to held-for-sale as a result of the business qualifying as a discontinued operation. As of September 30, 2020 and December 31, 2019, included in the table above were restricted investments of $146.5 million and $131.0 million, respectively. The unrealized gains (losses) on AFS investments balance in accumulated other comprehensive income (loss) ("AOCI"), a component of shareholders' equity, included $16.1 million and $(1.0) million as at September 30, 2020 and December 31, 2019, respectively, related to StarStone U.S. Upon completion of the sale, the balance at closing will be included in earnings as a component of the gain on sale. The StarStone U.S. business qualifies as a discontinued operation. The following table summarizes the components of net earnings (loss) from discontinued operations, net of income taxes, related to StarStone U.S., on the consolidated statements of earnings for the three and nine months ended September 30, 2020 and 2019: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 INCOME Net premiums earned $ 75,414 $ 94,523 $ 241,363 $ 263,464 Fees and commission income — 150 — 515 Net investment income 3,649 3,970 11,063 11,831 Net realized and unrealized gains 1,910 3,125 2,757 20,198 Other income 55 4 80 10 81,028 101,772 255,263 296,018 EXPENSES Net incurred losses and loss adjustment expenses 44,939 59,159 157,648 185,048 Acquisition costs 14,776 16,972 47,570 48,733 General and administrative expenses 16,675 16,558 47,404 47,213 Interest expense 535 — 1,715 1,355 Net foreign exchange (gains) losses (3) 34 (5) 29 76,922 92,723 254,332 282,378 EARNINGS (LOSS) BEFORE INCOME TAXES 4,106 9,049 931 13,640 Income tax benefit (expense) (75) (1,133) (121) (1,599) NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES $ 4,031 $ 7,916 $ 810 $ 12,041 Net loss (earnings) from discontinued operations attributable to noncontrolling interest (1,654) (3,247) (332) (4,939) NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 2,377 $ 4,669 $ 478 $ 7,102 The following table presents the cash flows of StarStone U.S. for the nine months ended September 30, 2020 and 2019: Nine Months Ended September 30, 2020 2019 Operating activities $ 114,024 $ 210,666 Investing activities (134,759) (5,332) Change in cash and restricted cash of business held-for-sale $ (20,735) $ 205,334 Intercompany transactions between StarStone U.S. (Discontinued Operations) and Continuing Operations The table below presents a summary of the total income and expenses recognized in continuing operations for the three and nine months ended September 30, 2020 and 2019, relating to intercompany transactions, primarily intragroup reinsurances, between StarStone U.S. and our other subsidiaries: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Total income $ 1,709 $ 3,373 $ 9,072 $ 8,082 Total expenses (income) (1,783) (4,582) (16,682) 41,884 Net earnings (loss) $ 3,492 $ 7,955 $ 25,754 $ (33,802) Run-off of StarStone International (non-U.S.) On June 10, 2020, we also announced that we placed StarStone International into an orderly run-off (the "StarStone International Run-Off"). The liabilities associated with the StarStone International Run-Off vary in duration, and the run-off is expected to occur over a number of years. Steps to reduce the size of StarStone International's operations have begun and will involve several phases to occur over time. As a result, we cannot anticipate with certainty the expected completion date of the StarStone International Run-Off. We continue to evaluate additional strategic options for StarStone International's operations and business. Consequently, such options could have the effect of mitigating costs associated with placing the business into run-off. The remaining StarStone International operations will continue to serve the needs of policyholders and ensure that the companies continue to meet all regulatory requirements. The results of StarStone International are included within continuing operations in the StarStone segment. Recent developments relating to StarStone International include: • On October 14, 2020, we completed the sale of Vander Haeghen & Co. SA ("VdH"), a Belgium-based insurance agency majority owned by two StarStone International entities, for a purchase price of €3.8 million ($4.5 million). We expect to recognize a gain on the sale of $3.6 million in the fourth quarter of 2020. • On October 2, 2020, StarStone International sold the renewal rights for its financial lines portfolio for consideration of approximately $0.5 million. Reconciliation to the Consolidated Balance Sheet The following table provides a reconciliation of the assets and liabilities of Northshore and StarStone U.S. held-for-sale on our consolidated balance sheet: September 30, 2020 Assets held-for-sale: Northshore (Atrium and Arden Re) $ 650,978 StarStone U.S. 1,505,510 Total $ 2,156,488 Liabilities held-for-sale: Northshore (Atrium and Arden Re) $ 431,086 StarStone U.S. 1,222,257 Total $ 1,653,343

Investments

Investments	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	5. 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. 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: September 30, 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 $ 3,399 $ 252,449 $ 148,378 $ 298,140 $ 87,264 $ 789,630 U.K. government — — 71,803 42,974 — 114,777 Other government 2,872 — 327,406 136,130 24,039 490,447 Corporate 862 25,726 3,474,857 1,653,722 524,742 5,679,909 Municipal — — 79,296 30,806 51,737 161,839 Residential mortgage-backed — — 157,773 293,811 77,655 529,239 Commercial mortgage-backed — — 382,735 228,207 232,177 843,119 Asset-backed — — 357,394 199,682 56,587 613,663 Total fixed maturity and short-term investments $ 7,133 $ 278,175 $ 4,999,642 $ 2,883,472 $ 1,054,201 $ 9,222,623 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 $ 208,296 $ 269,661 $ 106,537 $ 696,077 U.K. government 24,411 1,069 122,012 14,280 — 161,772 Other government 21,958 387 575,017 84,760 20,734 702,856 Corporate 5,121 13,915 3,959,288 866,557 603,389 5,448,270 Municipal — 1,381 87,451 2,399 49,456 140,687 Residential mortgage-backed — — 215,521 99,188 86,205 400,914 Commercial mortgage-backed — — 534,357 49,046 230,343 813,746 Asset-backed — — 441,393 152,161 76,681 670,235 Total fixed maturity and short-term investments $ 51,490 $ 128,335 $ 6,143,335 $ 1,538,052 $ 1,173,345 $ 9,034,557 Included within residential and commercial mortgage-backed securities as of September 30, 2020 were securities issued by U.S. governmental agencies with a fair value of $458.8 million (December 31, 2019: $333.3 million). Included within corporate securities as of September 30, 2020 were senior secured loans of $nil (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 September 30, 2020 Amortized Fair Value % of Total One year or less $ 556,125 $ 559,086 6.1 % More than one year through two years 589,231 598,559 6.5 % More than two years through five years 2,080,715 2,163,967 23.5 % More than five years through ten years 2,010,769 2,149,170 23.3 % More than ten years 1,595,695 1,765,820 19.1 % Residential mortgage-backed 521,383 529,239 5.7 % Commercial mortgage-backed 821,995 843,119 9.1 % Asset-backed 631,133 613,663 6.7 % $ 8,807,046 $ 9,222,623 100.0 % 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 September 30, 2020: Amortized Fair Value % of Total AAA AA Rated A Rated BBB Non- Not Rated U.S. government and agency $ 769,544 $ 789,630 8.6 % $ 789,630 $ — $ — $ — $ — $ — U.K. government 111,169 114,777 1.2 % — 102,624 8,739 — — 3,414 Other government 466,575 490,447 5.3 % 242,097 150,005 43,003 45,884 9,458 — Corporate 5,339,160 5,679,909 61.6 % 206,345 583,595 2,704,861 1,912,857 267,765 4,486 Municipal 146,087 161,839 1.8 % 7,137 83,519 51,538 19,645 — — Residential mortgage-backed 521,383 529,239 5.7 % 517,915 — 2,154 1,612 5,251 2,307 Commercial mortgage-backed 821,995 843,119 9.1 % 576,643 111,720 77,391 64,898 5,308 7,159 Asset-backed 631,133 613,663 6.7 % 249,237 99,942 145,494 96,960 21,780 250 Total $ 8,807,046 $ 9,222,623 100.0 % $ 2,589,004 $ 1,131,405 $ 3,033,180 $ 2,141,856 $ 309,562 $ 17,616 % of total fair value 28.1 % 12.3 % 32.9 % 23.2 % 3.3 % 0.2 % 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 September 30, 2020 were as follows: Gross Unrealized Losses As of September 30, 2020 Amortized Cost Gross Unrealized Gains Non-Credit Related Losses Allowance for Credit Losses (1) Fair Value U.S. government and agency $ 546,799 $ 4,071 $ (281) $ — $ 550,589 U.K. government 42,025 995 (46) — 42,974 Other government 131,861 4,279 (10) — 136,130 Corporate 1,646,014 40,601 (6,383) (784) 1,679,448 Municipal 29,810 1,012 (16) — 30,806 Residential mortgage-backed 292,153 2,211 (551) (2) 293,811 Commercial mortgage-backed 226,292 4,347 (2,351) (81) 228,207 Asset-backed 200,626 642 (1,541) (45) 199,682 $ 3,115,580 $ 58,158 $ (11,179) $ (912) $ 3,161,647 (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 Fair Value U.S. government and agency $ 381,488 $ 78 $ (322) $ 381,244 U.K. government 15,067 282 — 15,349 Other government 84,116 1,119 (88) 85,147 Corporate 880,667 3,739 (3,934) 880,472 Municipal 3,770 12 (2) 3,780 Residential mortgage-backed 99,646 221 (679) 99,188 Commercial mortgage-backed 49,219 30 (203) 49,046 Asset-backed 152,153 127 (119) 152,161 $ 1,666,126 $ 5,608 $ (5,347) $ 1,666,387 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 September 30, 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 September 30, 2020 Fair Gross Unrealized Fair Gross Unrealized Fair Gross Unrealized U.S. government and agency $ — $ — $ 170,590 $ (281) $ 170,590 $ (281) U.K. government — — 2,911 (46) 2,911 (46) Other government — — 7,392 (10) 7,392 (10) Corporate — — 498,974 (5,585) 498,974 (5,585) Municipal — — 3,551 (16) 3,551 (16) Residential mortgage-backed — — 136,602 (383) 136,602 (383) Commercial mortgage-backed — — 69,226 (1,652) 69,226 (1,652) Asset-backed — — 135,857 (1,386) 135,857 (1,386) Total fixed maturity and short-term investments $ — $ — $ 1,025,103 $ (9,359) $ 1,025,103 $ (9,359) 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 Gross Unrealized Fair Gross Unrealized Fair Gross Unrealized U.S. government and agency $ — $ — $ 193,574 $ (322) $ 193,574 $ (322) Other government 1,080 (23) 37,796 (65) 38,876 (88) Corporate 2,754 (306) 338,965 (3,628) 341,719 (3,934) Municipal 128 — 761 (2) 889 (2) Residential mortgage-backed — — 52,005 (679) 52,005 (679) Commercial mortgage-backed — — 35,777 (203) 35,777 (203) Asset-backed — — 101,591 (119) 101,591 (119) Total fixed maturity and short-term investments $ 3,962 $ (329) $ 760,469 $ (5,018) $ 764,431 $ (5,347) As of September 30, 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 721 and 479, respectively. Of these securities, the number of securities that had been in an unrealized loss position for twelve months or longer was 0 and 12, respectively. Allowance for Credit Losses on AFS Fixed Maturity Investments We adopted ASU 2016-13 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 following tables provide a reconciliation of the beginning and ending allowance for credit losses on our AFS debt securities: Three Months Ended September 30, 2020 Other Corporate Residential mortgage-backed Commercial Asset-backed Total Allowance for credit losses, beginning of period $ — $ (3,090) $ — $ (494) $ (89) $ (3,673) Cumulative effect of change in accounting principle — — — — — — Allowances for credit losses on securities for which credit losses were not previously recorded — (39) (2) (78) (45) (164) Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets — — — — — — Reductions for securities sold during the period — 341 — — — 341 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 — — — — — — (Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period — 2,004 — 491 89 2,584 Allowance for credit losses, end of period $ — $ (784) $ (2) $ (81) $ (45) $ (912) Nine Months Ended September 30, 2020 Other Corporate Residential mortgage-backed Commercial Asset-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 — (10,359) (2) (572) (134) (11,067) Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets — — — — — — Reductions for securities sold during the period 22 2,108 — — — 2,130 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 — — — — — — (Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period — 10,454 — 541 89 11,084 Allowance for credit losses, end of period $ — $ (784) $ (2) $ (81) $ (45) $ (912) During the three and nine months ended September 30, 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 decreased during the three months ended September 30, 2020 primarily due to improved market conditions. Our modeling process for determining credit losses remained the same as the prior quarter and took into account the adverse impact that the COVID-19 pandemic still has on capital markets and the global economy in general. Other-Than-Temporary Impairment on AFS Fixed Maturity Investments For the three and nine months ended September 30, 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: September 30, 2020 December 31, 2019 Publicly traded equity investments in common and preferred stocks $ 303,932 $ 327,875 Exchange-traded funds 78,182 133,047 Privately held equity investments in common and preferred stocks 271,045 265,799 $ 653,159 $ 726,721 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. Other Investments, at fair value The following table summarizes our other investments carried at fair value: September 30, 2020 December 31, 2019 Hedge funds $ 2,087,091 $ 1,121,904 Fixed income funds 684,031 481,039 Equity funds 290,129 410,149 Private equity funds 320,455 323,496 CLO equities 84,532 87,555 CLO equity funds 140,458 87,509 Private credit funds 90,476 — Other 7,698 6,379 $ 3,704,870 $ 2,518,031 The valuation of our other investments is described in Note 11 - "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. 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, including derivatives, 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, in both liquid and illiquid markets. The liquid fixed income 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 and a fund that provides loans to educational institutions throughout the U.S. and its territories. The increase in our other investments carried at fair value between September 30, 2020 and December 31, 2019 was primarily attributable to unrealized gains of $670.7 million and net additional subscriptions of $530.3 million to hedge funds, fixed income funds, private credit funds, CLO equities and CLO equity funds. As of September 30, 2020, we had unfunded commitments of $792.2 million to other investments. 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 September 30, 2020: Less than 1 Year 1-2 years 2-3 years Not Eligible/ Restricted Total Redemption Frequency Hedge funds $ 793,268 $ 1,131,505 $ 102,600 $ 59,718 $ 2,087,091 Monthly to Bi-annually Fixed income funds 671,333 — — 12,698 684,031 Daily to Quarterly Equity funds 290,129 — — — 290,129 Daily to Quarterly Private equity funds — — — 320,455 320,455 N/A CLO equities 84,532 — — — 84,532 N/A CLO equity funds 101,597 29,113 9,748 — 140,458 Quarterly to Bi-annually Private credit funds — 10,000 80,476 90,476 N/A Other 7,698 7,698 N/A $ 1,940,859 $ 1,170,618 $ 112,348 $ 481,045 $ 3,704,870 Refer to Note 20 - "Related Party Transactions" for further information regarding certain of our other investments. Equity Method Investments The following table summarizes our equity method investments: September 30, 2020 December 31, 2019 Investment Ownership % Carrying Value Investment Ownership % Carrying Value Enhanzed Re $ 154,050 47.4 % $ 271,678 $ 154,050 47.4 % $ 182,856 Citco 50,000 31.9 % 51,946 50,000 31.9 % 51,742 Monument Re (1) 59,600 20.0 % 161,994 26,600 20.0 % 60,598 Clear Spring 11,210 20.0 % 10,944 11,210 20.0 % 10,645 Other 24,963 ~30% 20,233 24,963 ~30% 20,436 $ 299,823 $ 516,795 $ 266,823 $ 326,277 (1) We own 20.0% of the common shares in Monument Re as well as different classes of preferred shares which have fixed dividend yields. Refer to Note 20 - "Related Party Transactions" for further information regarding our investments in Enhanzed Re, Citco, Monument Re and Clear Spring. As of September 30, 2020, we had unfunded commitments of $68.7 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: September 30, 2020 December 31, 2019 Fixed maturity investments, trading $ 1,054,201 $ 1,173,345 Cash and cash equivalents 6,432 10,296 Other assets 6,006 3,911 $ 1,066,639 $ 1,187,552 The following table summarizes the fixed maturity investment components of funds held - directly managed: September 30, 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 $ 106,768 $ 861,511 $ 968,279 $ 185,859 $ 940,194 $ 1,126,053 Net unrealized gains (losses): Change in fair value - fair value option accounting 9,077 — 9,077 5,438 — 5,438 Change in fair value - embedded derivative accounting — 76,845 76,845 — 41,854 41,854 Fixed maturity investments within funds held - directly managed, at fair value $ 115,845 $ 938,356 $ 1,054,201 $ 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 Net Investment Income Major categories of net investment income are summarized as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Fixed maturity investments $ 47,275 $ 54,085 $ 153,554 $ 163,246 Short-term investments and cash and cash equivalents 826 3,526 4,203 11,430 Funds held 8,346 10,091 32,715 18,901 Funds held - directly managed 7,703 9,381 27,204 28,742 Investment income from fixed maturities and cash and cash equivalents 64,150 77,083 217,676 222,319 Equity investments 4,771 4,416 14,496 11,218 Other investments 6,000 2,642 19,384 7,259 Investment income from equities and other investments 10,771 7,058 33,880 18,477 Gross investment income 74,921 84,141 251,556 240,796 Investment expenses (2,791) (2,639) (10,269) (9,372) Net investment income $ 72,130 $ 81,502 $ 241,287 $ 231,424 Net Realized and Unrealized Gains Components of net realized and unrealized gains were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Net realized gains (losses) on sale: Gross realized gains on fixed maturity securities, AFS $ 9,871 $ 44 $ 19,995 $ 4,493 Gross realized losses on fixed maturity securities, AFS (786) (10) (7,379) (302) Credit recoveries (losses) on fixed maturity securities, AFS 2,248 — (389) — Net realized gains on fixed maturity securities, trading 30,531 25,245 87,911 45,636 Net realized gains on funds held - directly managed 3,292 1,991 5,545 629 Net realized gains (losses) on equity investments 8,286 (3,881) 9,165 (1,213) Net realized investment gains (losses) on derivatives 46 — 46 — Total net realized gains on sale $ 53,488 $ 23,389 $ 114,894 $ 49,243 Net unrealized gains (losses): Fixed maturity securities, trading $ 14,324 $ 86,840 $ 58,795 $ 413,175 Fixed maturity securities in funds held - directly managed portfolios 7,814 20,895 42,619 95,124 Equity investments 4,210 10,057 (48,409) 31,266 Other Investments 420,169 3,879 670,653 269,681 Total net unrealized gains 446,517 121,671 723,658 809,246 Net realized and unrealized gains $ 500,005 $ 145,060 $ 838,552 $ 858,489 The gross realized gains and losses on AFS investments included in the table above resulted from sales of $409.6 million and $7.6 million for the three months ended September 30, 2020 and 2019, respectively, and $1,455.9 million and $91.2 million for the nine months ended September 30, 2020 and 2019, respectively. Reconciliation to the Consolidated Statements of Comprehensive Income The following table provides a reconciliation of the gross realized gains and losses and credit recoveries (losses) on our AFS fixed maturity debt securities that arose during the three and nine months ended September 30, 2020 within our continuing and discontinued operations and the offsetting reclassification adjustments included within our consolidated statements of comprehensive income: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Included within continuing operations: Gross realized gains on fixed maturity securities, AFS $ 9,871 $ 44 $ 19,995 $ 4,493 Gross realized losses on fixed maturity securities, AFS (786) (10) (7,379) (302) Included within discontinued operations: Gross realized gains on fixed maturity securities, AFS 489 12 1,025 12 Gross realized losses on fixed maturity securities, AFS (86) (12) (143) (12) Total reclassification adjustment $ 9,488 $ 34 $ 13,498 $ 4,191 Included within continuing operations: Credit recoveries (losses) on fixed maturity securities, AFS $ 2,248 $ — $ (389) $ — Included within discontinued operations: Credit recoveries (losses) on fixed maturity securities, AFS 131 — 318 — Total reclassification adjustment $ 2,379 $ — $ (71) $ — 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 $556.7 million and $346.9 million, as of September 30, 2020 and December 31, 2019, respectively, was as follows: September 30, 2020 December 31, 2019 Collateral in trust for third party agreements $ 5,189,537 $ 4,103,847 Assets on deposit with regulatory authorities 276,941 309,659 Collateral for secured letter of credit facilities 121,700 132,670 Funds at Lloyd's (1) 546,996 639,316 $ 6,135,174 $ 5,185,492 (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 14 - "Debt Obligations and Credit Facilities." The increase in restricted assets during the nine months ended September 30, 2020 primarily related to new business as described in Note 3 - "Significant New Business," partially offset by reductions due to paid losses and other releases of collateral.

Derivative and Hedging Instrume

Derivative and Hedging Instruments	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE AND HEDGING INSTRUMENTS	6. 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 September 30, 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: September 30, 2020 December 31, 2019 Fair Value Fair Value Gross Notional Amount Assets Liabilities Gross Notional Amount Assets Liabilities Foreign currency forward - AUD $ 68,847 $ 282 $ — $ 64,620 $ 52 $ 2,033 Foreign currency forward - EUR 140,663 839 — 112,284 246 1,635 Foreign currency forward - GBP 329,245 5,664 — 318,387 344 7,784 Total qualifying hedges $ 538,755 $ 6,785 $ — $ 495,291 $ 642 $ 11,452 The following table presents the net gains and losses deferred in the cumulative translation adjustment ("CTA") account, which is a component of AOCI, in shareholders' equity, relating to our foreign currency forward exchange rate contracts: Amount of Gains (Losses) Deferred in AOCI Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Foreign currency forward - AUD $ (2,813) $ 1,673 $ (1,777) $ 1,819 Foreign currency forward - EUR (5,525) 4,780 (6,001) 5,076 Foreign currency forward - GBP (11,315) 8,260 10,002 6,669 Net gains (losses) on qualifying derivative hedges $ (19,653) $ 14,713 $ 2,224 $ 13,564 Derivatives Not Designated or Not Qualifying as Net Investments 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 exchange rate hedging relationships: September 30, 2020 December 31, 2019 Fair Value Fair Value Gross Notional Amount Assets Liabilities Gross Notional Amount Assets Liabilities Foreign currency forward - AUD $ 19,076 $ 145 $ 81 $ 913 $ 839 $ 892 Foreign currency forward - CAD 52,212 525 89 66,266 10 1,482 Foreign currency forward - EUR 22,272 — 132 74,444 507 1,440 Foreign currency forward - GBP 43,254 744 — 11,940 13 292 Total non-qualifying hedges $ 136,814 $ 1,414 $ 302 $ 153,563 $ 1,369 $ 4,106 The following table presents 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Foreign currency forward - AUD $ 13 $ 1,148 $ (432) $ 1,710 Foreign currency forward - CAD (1,171) 1,582 1,600 (910) Foreign currency forward - EUR (817) 2,473 135 3,344 Foreign currency forward - GBP (2,219) 10,659 (719) $ 12,970 Net gains (losses) on non-qualifying hedges $ (4,194) $ 15,862 $ 584 $ 17,114 Investments in Call Options on Equities During the three and nine months ended September 30, 2020, we recorded unrealized losses of $nil and less than $0.1 million, respectively, in net earnings on the call options on equities that we had purchased in 2018 at a cost of $10.0 million. During the three and nine months ended September 30, 2019, we had recorded unrealized gains of less than $0.1 million and $1.3 million, respectively, in net earnings on these call options on equities. These call options on equities had a fair value of less than $0.1 million as at December 31, 2019 and expired without being exercised during the nine months ended September 30, 2020. Forward Interest Rate Swaps 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 which closed on July 1, 2020, as described in Note 3 - "Significant New Business." During the three and nine months ended September 30, 2020, we recorded unrealized gains included within net earnings of $nil and $0.8 million, respectively, on the forward interest rate swap. This forward interest rate swap was terminated on April 7, 2020, for an inception-to-date net realized gain of $0.5 million. The carrying value of the forward interest rate swap, recorded in other liabilities as of December 31, 2019, was $0.3 million. Credit Default Swaps, Futures and Currency Forward Contracts From time to time we may also utilize (i) credit default swaps to both hedge and replicate credit exposure, (ii) government bond futures contracts for interest rate management, and (iii) foreign currency forward contracts for currency hedging, to collectively manage credit and duration risk, as well as for yield enhancement on some of our fixed income portfolios. The following table presents the gross notional amounts and estimated fair values recorded within other assets and other liabilities related to our credit default swaps, government bond futures contracts and currency forward contracts: September 30, 2020 Fair Value Gross Notional Amount Assets Liabilities Credit default swaps $ 7,865 $ — $ 169 Futures contracts - long positions 48,051 100 — Futures contracts - short positions (33,318) — 85 Currency forward contracts - long positions 1,508 12 — Currency forward contracts - short positions (1,819) — 29 Total $ 22,287 $ 112 $ 283 We initially entered into these credit default swaps, government bond futures contracts and currency forward contracts during the nine month period ended September 30, 2020 and therefore we did not have any of these contracts in place as of December 31, 2019. The following table presents the amounts of the net gains included in earnings related to our credit default swaps, government bond futures contracts and currency forward contracts: Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Credit default swaps $ 106 $ 106 Futures contracts (6) (43) Currency forward contracts (43) 123 Total net gains $ 57 $ 186 We initially entered into these credit default swaps, government bond futures contracts and currency forward contracts during the nine month period ended September 30, 2020 and therefore we did not have any of these contracts in place during the three and nine months ended September 30, 2019.

Reinsurance Balances Recoverabl

Reinsurance Balances Recoverable on Paid and Unpaid Losses	9 Months Ended
	Sep. 30, 2020
Insurance [Abstract]
REINSURANCE BALANCES RECOVERABLE ON PAID AND UNPAID LOSSES	$1 million 556,623 132,049 688,672 36.6 % Other reinsurers < $1 million 18,687 1,374 20,061 1.1 % Total $ 1,403,789 $ 477,867 $ 1,881,656 100.0 % December 31, 2019 Non-life Atrium StarStone Total % of Top 10 reinsurers $ 1,154,110 $ 22,051 $ 295,443 $ 1,471,604 67.4 % Other reinsurers > $1 million 551,636 7,761 129,335 688,732 31.6 % Other reinsurers < $1 million 19,243 545 1,010 20,798 1.0 % Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 100.0 % September 30, 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 $ 910,751 $ 1,199,479 Non-rated reinsurers in top 10 (1) 262,172 272,125 Total top 10 reinsurance recoverables $ 1,172,923 $ 1,471,604 Single reinsurers that represent 10% or more of total reinsurance balance recoverables as of September 30, 2020: Hannover Ruck SE (2) $ — $ 259,077 Lloyd's Syndicates (3) $ 346,601 $ 396,246 (1) The reinsurance balances recoverable from the two non-rated top 10 reinsurers was comprised of: • $183.4 million and $190.8 million as of September 30, 2020 and December 31, 2019 respectively, due from a US state backed reinsurer that is supported by assessments on active auto writers operating within the state; and • $78.8 million and $81.4 million as of September 30, 2020 and December 31, 2019 respectively, due from a reinsurer who has provided us with security in the form of pledged assets in trust for the full amount of the recoverable balance. (2) Hannover Ruck SE is rated AA- by Standard & Poor’s and A+ by A.M. Best. The transaction described in Note 3 - "Significant New Business" had the effect of moving this reinsurer to be less than 10%. (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 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. September 30, 2020 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,429,984 $ 57,465 $ 1,372,519 4.0 % Reinsurers rated below A-, secured 419,431 — 419,431 — % Reinsurers rated below A-, unsecured 167,358 77,652 89,706 46.4 % Total $ 2,016,773 $ 135,117 $ 1,881,656 6.7 % December 31, 2019 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,731,270 $ 43,427 $ 1,687,843 2.5 % Reinsurers rated below A-, secured 463,840 — 463,840 — % Reinsurers rated below A-, unsecured 133,663 104,212 29,451 78.0 % Total $ 2,328,773 $ 147,639 $ 2,181,134 6.3 % The table below provides a reconciliation of the beginning and ending allowance for estimated uncollectible reinsurance balances for the three and nine months ended September 30, 2020: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Allowance for estimated uncollectible reinsurance, beginning of period $ 143,653 $ 147,639 Cumulative effect of change in accounting principle — (195) Effect of exchange rate movement 745 (701) Current period change in the allowance 815 (718) Write-offs charged against the allowance (9,625) (10,225) Recoveries collected (471) (683) Allowance for estimated uncollectible reinsurance, end of period $ 135,117 $ 135,117 Past-Due Status: We consider a reinsurance recoverable asset to be past due when it is 90 days past due and record a credit allowance when there is reasonable uncertainty about the collectability of a disputed amount during the reporting period. We did not have significant past due balances older than one year for any of the periods presented. 12. 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Premiums Premiums Premiums Premiums Premiums Premiums Premiums Premiums Non-life Run-off Gross $ 3,535 $ 20,426 $ 301 $ 27,190 $ 1,707 $ 52,899 $ (24,785) $ 166,707 Ceded (111) (2,950) (4,109) (10,353) 690 (8,876) (1,610) (24,726) Net $ 3,424 $ 17,476 $ (3,808) $ 16,837 $ 2,397 $ 44,023 $ (26,395) $ 141,981 Atrium Gross $ 49,083 $ 48,690 $ 48,746 $ 48,340 $ 155,551 $ 144,675 $ 146,519 $ 133,610 Ceded (2,580) (6,264) (4,961) (5,427) (19,458) (16,492) (19,273) (13,745) Net $ 46,503 $ 42,426 $ 43,785 $ 42,913 $ 136,093 $ 128,183 $ 127,246 $ 119,865 StarStone Gross $ 58,566 $ 123,813 $ 110,586 $ 151,895 $ 300,135 $ 362,638 $ 363,352 $ 409,135 Ceded (15,228) (27,697) (34,566) (40,146) (73,069) (86,072) (72,269) (69,142) Net $ 43,338 $ 96,116 $ 76,020 $ 111,749 $ 227,066 $ 276,566 $ 291,083 $ 339,993 Other Gross $ 293 $ 5,705 $ (2,498) $ 4,338 $ 3,237 $ 15,173 $ (1,174) $ 17,024 Ceded 1 1 (5) (35) 1 1 (23) (152) Net $ 294 $ 5,706 $ (2,503) $ 4,303 $ 3,238 $ 15,174 $ (1,197) $ 16,872 Total Gross $ 111,477 $ 198,634 $ 157,135 $ 231,763 $ 460,630 $ 575,385 $ 483,912 $ 726,476 Ceded (17,918) (36,910) (43,641) (55,961) (91,836) (111,439) (93,175) (107,765) Total $ 93,559 $ 161,724 $ 113,494 $ 175,802 $ 368,794 $ 463,946 $ 390,737 $ 618,711 Gross premiums written for the three months ended September 30, 2020 and 2019 were $111.5 million and $157.1 million, respectively, a decrease of $45.7 million. The decrease was primarily due to a decrease in gross premiums written in our StarStone segment of $52.0 million, partially offset by an increase Non-life Run-off segment of $3.2 million. The decrease in the StarStone segment was due to StarStone International being placed into an orderly run-off. Gross premiums written for the nine months ended September 30, 2020 and 2019 were $460.6 million and $483.9 million, respectively, a decrease of $23.3 million. The decrease was primarily due to a decrease in gross premiums written in our StarStone segment of $63.2 million, partially offset by a reduction in negative gross premiums written in our Non-life Run-off segment of $26.5 million and an increase in the Atrium segment of $9.0 million. The decrease in the StarStone segment was primarily due to StarStone International being placed into an orderly run-off. The negative gross premium written in the Non-life Run-off segment for the nine months ended September 30, 2019 was due to premium adjustments on the acquired unearned premium primarily related to the run-off business assumed as a result of the AmTrust RITC transactions and the acquisition of Maiden Re North America. The increase in the Atrium segment was driven by increases in the binding authorities, marine, aviation and transit and non-marine direct and facultative lines of business. The binding authorities line of business benefited from new opportunities to write new business, while the marine, aviation and non-marine direct and facultative lines of business continued to benefit from an increase in rates and new opportunities in the U.S." id="sjs-B4">7. REINSURANCE BALANCES RECOVERABLE ON PAID AND UNPAID LOSSES The following tables provide the total reinsurance balances recoverable on paid and unpaid losses: September 30, 2020 Non-life StarStone Total Recoverable from reinsurers on unpaid: Outstanding losses $ 858,988 $ 258,215 $ 1,117,203 IBNR 439,594 143,073 582,667 ULAE 7,674 — 7,674 Fair value adjustments - acquired companies (11,986) (1,378) (13,364) Fair value adjustments - fair value option (27,029) — (27,029) Total reinsurance reserves recoverable 1,267,241 399,910 1,667,151 Paid losses recoverable 136,548 77,957 214,505 Total $ 1,403,789 $ 477,867 $ 1,881,656 Reconciliation to Consolidated Balance Sheet: Reinsurance balances recoverable on paid and unpaid losses $ 860,628 $ 477,867 $ 1,338,495 Reinsurance balances recoverable on paid and unpaid losses - fair value option 543,161 — 543,161 Total $ 1,403,789 $ 477,867 $ 1,881,656 December 31, 2019 Non-life Atrium StarStone Total Recoverable from reinsurers on unpaid: Outstanding losses $ 972,293 $ 9,011 $ 264,131 $ 1,245,435 IBNR 673,059 19,286 93,185 785,530 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 28,816 355,194 1,927,624 Paid losses recoverable 181,375 1,541 70,594 253,510 Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 Reconciliation to Consolidated Balance Sheet: Reinsurance balances recoverable on paid and unpaid losses $ 1,029,471 $ 30,357 $ 425,788 $ 1,485,616 Reinsurance balances recoverable on paid and unpaid losses - fair value option 695,518 — — 695,518 Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 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, StarStone purchases a tailored outwards reinsurance program designed to manage its risk profile. The majority of 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 11 - "Fair Value Measurements." As of September 30, 2020 and December 31, 2019, we had reinsurance balances recoverable on paid and unpaid losses of $1.9 billion and $2.2 billion, respectively. The decrease of $299.5 million in reinsurance balances Top Ten Reinsurers September 30, 2020 Non-life StarStone Total % of Top 10 reinsurers $ 828,479 $ 344,444 $ 1,172,923 62.3 % Other reinsurers > $1 million 556,623 132,049 688,672 36.6 % Other reinsurers < $1 million 18,687 1,374 20,061 1.1 % Total $ 1,403,789 $ 477,867 $ 1,881,656 100.0 % December 31, 2019 Non-life Atrium StarStone Total % of Top 10 reinsurers $ 1,154,110 $ 22,051 $ 295,443 $ 1,471,604 67.4 % Other reinsurers > $1 million 551,636 7,761 129,335 688,732 31.6 % Other reinsurers < $1 million 19,243 545 1,010 20,798 1.0 % Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 100.0 % September 30, 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 $ 910,751 $ 1,199,479 Non-rated reinsurers in top 10 (1) 262,172 272,125 Total top 10 reinsurance recoverables $ 1,172,923 $ 1,471,604 Single reinsurers that represent 10% or more of total reinsurance balance recoverables as of September 30, 2020: Hannover Ruck SE (2) $ — $ 259,077 Lloyd's Syndicates (3) $ 346,601 $ 396,246 (1) The reinsurance balances recoverable from the two non-rated top 10 reinsurers was comprised of: • $183.4 million and $190.8 million as of September 30, 2020 and December 31, 2019 respectively, due from a US state backed reinsurer that is supported by assessments on active auto writers operating within the state; and • $78.8 million and $81.4 million as of September 30, 2020 and December 31, 2019 respectively, due from a reinsurer who has provided us with security in the form of pledged assets in trust for the full amount of the recoverable balance. (2) Hannover Ruck SE is rated AA- by Standard & Poor’s and A+ by A.M. Best. The transaction described in Note 3 - "Significant New Business" had the effect of moving this reinsurer to be less than 10%. (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 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. September 30, 2020 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,429,984 $ 57,465 $ 1,372,519 4.0 % Reinsurers rated below A-, secured 419,431 — 419,431 — % Reinsurers rated below A-, unsecured 167,358 77,652 89,706 46.4 % Total $ 2,016,773 $ 135,117 $ 1,881,656 6.7 % December 31, 2019 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,731,270 $ 43,427 $ 1,687,843 2.5 % Reinsurers rated below A-, secured 463,840 — 463,840 — % Reinsurers rated below A-, unsecured 133,663 104,212 29,451 78.0 % Total $ 2,328,773 $ 147,639 $ 2,181,134 6.3 % The table below provides a reconciliation of the beginning and ending allowance for estimated uncollectible reinsurance balances for the three and nine months ended September 30, 2020: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Allowance for estimated uncollectible reinsurance, beginning of period $ 143,653 $ 147,639 Cumulative effect of change in accounting principle — (195) Effect of exchange rate movement 745 (701) Current period change in the allowance 815 (718) Write-offs charged against the allowance (9,625) (10,225) Recoveries collected (471) (683) Allowance for estimated uncollectible reinsurance, end of period $ 135,117 $ 135,117 Past-Due Status: We consider a reinsurance recoverable asset to be past due when it is 90 days past due and record a credit allowance when there is reasonable uncertainty about the collectability of a disputed amount during the reporting period. We did not have significant past due balances older than one year for any of the periods presented. 12. 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Premiums Premiums Premiums Premiums Premiums Premiums Premiums Premiums Non-life Run-off Gross $ 3,535 $ 20,426 $ 301 $ 27,190 $ 1,707 $ 52,899 $ (24,785) $ 166,707 Ceded (111) (2,950) (4,109) (10,353) 690 (8,876) (1,610) (24,726) Net $ 3,424 $ 17,476 $ (3,808) $ 16,837 $ 2,397 $ 44,023 $ (26,395) $ 141,981 Atrium Gross $ 49,083 $ 48,690 $ 48,746 $ 48,340 $ 155,551 $ 144,675 $ 146,519 $ 133,610 Ceded (2,580) (6,264) (4,961) (5,427) (19,458) (16,492) (19,273) (13,745) Net $ 46,503 $ 42,426 $ 43,785 $ 42,913 $ 136,093 $ 128,183 $ 127,246 $ 119,865 StarStone Gross $ 58,566 $ 123,813 $ 110,586 $ 151,895 $ 300,135 $ 362,638 $ 363,352 $ 409,135 Ceded (15,228) (27,697) (34,566) (40,146) (73,069) (86,072) (72,269) (69,142) Net $ 43,338 $ 96,116 $ 76,020 $ 111,749 $ 227,066 $ 276,566 $ 291,083 $ 339,993 Other Gross $ 293 $ 5,705 $ (2,498) $ 4,338 $ 3,237 $ 15,173 $ (1,174) $ 17,024 Ceded 1 1 (5) (35) 1 1 (23) (152) Net $ 294 $ 5,706 $ (2,503) $ 4,303 $ 3,238 $ 15,174 $ (1,197) $ 16,872 Total Gross $ 111,477 $ 198,634 $ 157,135 $ 231,763 $ 460,630 $ 575,385 $ 483,912 $ 726,476 Ceded (17,918) (36,910) (43,641) (55,961) (91,836) (111,439) (93,175) (107,765) Total $ 93,559 $ 161,724 $ 113,494 $ 175,802 $ 368,794 $ 463,946 $ 390,737 $ 618,711 Gross premiums written for the three months ended September 30, 2020 and 2019 were $111.5 million and $157.1 million, respectively, a decrease of $45.7 million. The decrease was primarily due to a decrease in gross premiums written in our StarStone segment of $52.0 million, partially offset by an increase Non-life Run-off segment of $3.2 million. The decrease in the StarStone segment was due to StarStone International being placed into an orderly run-off. Gross premiums written for the nine months ended September 30, 2020 and 2019 were $460.6 million and $483.9 million, respectively, a decrease of $23.3 million. The decrease was primarily due to a decrease in gross premiums written in our StarStone segment of $63.2 million, partially offset by a reduction in negative gross premiums written in our Non-life Run-off segment of $26.5 million and an increase in the Atrium segment of $9.0 million. The decrease in the StarStone segment was primarily due to StarStone International being placed into an orderly run-off. The negative gross premium written in the Non-life Run-off segment for the nine months ended September 30, 2019 was due to premium adjustments on the acquired unearned premium primarily related to the run-off business assumed as a result of the AmTrust RITC transactions and the acquisition of Maiden Re North America. The increase in the Atrium segment was driven by increases in the binding authorities, marine, aviation and transit and non-marine direct and facultative lines of business. The binding authorities line of business benefited from new opportunities to write new business, while the marine, aviation and non-marine direct and facultative lines of business continued to benefit from an increase in rates and new opportunities in the U.S.

Deferred Charge Assets

Deferred Charge Assets	9 Months Ended
	Sep. 30, 2020
Insurance [Abstract]
DEFERRED CHARGE ASSETS	8. 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Beginning carrying value $ 258,516 $ 99,094 $ 272,462 $ 86,585 Recorded during the period — 85,183 11,746 108,689 Amortization (10,316) (17,009) (36,008) (28,006) Ending carrying value $ 248,200 $ 167,268 $ 248,200 $ 167,268 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 nine months ended September 30, 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. Further information on deferred charge assets recorded during the three and nine months ended September 30, 2020 is included in Note 3 - "Significant New Business."

Losses and Loss Adjustment Expe

Losses and Loss Adjustment Expenses	9 Months Ended
	Sep. 30, 2020
Insurance [Abstract]
LOSSES AND LOSS ADJUSTMENT EXPENSES	9. 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: September 30, 2020 Non-life StarStone Other Total Outstanding losses $ 4,461,854 $ 698,118 $ 10,479 $ 5,170,451 IBNR 4,360,063 611,986 15,817 4,987,866 Fair value adjustments - acquired companies (147,500) (339) — (147,839) Fair value adjustments - fair value option (81,299) — — (81,299) ULAE 330,472 41,233 — 371,705 Total $ 8,923,590 $ 1,350,998 $ 26,296 $ 10,300,884 Reconciliation to Consolidated Balance Sheet: Loss and loss adjustment expenses $ 6,500,912 $ 1,350,998 $ 26,296 $ 7,878,206 Loss and loss adjustment expenses, at fair value 2,422,678 — — 2,422,678 Total $ 8,923,590 $ 1,350,998 $ 26,296 $ 10,300,884 December 31, 2019 Non-life Atrium StarStone Other Total Outstanding losses $ 4,407,082 $ 89,141 $ 743,829 $ 9,512 $ 5,249,564 IBNR 3,945,407 136,543 556,135 13,565 4,651,650 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 18,852 — 352,634 Total $ 8,295,361 $ 231,672 $ 1,318,294 $ 23,077 $ 9,868,404 Reconciliation to Consolidated Balance Sheet: Loss and loss adjustment expenses $ 5,674,239 $ 231,672 $ 1,318,294 $ 23,077 $ 7,247,282 Loss and loss adjustment expenses, at fair value 2,621,122 — — — 2,621,122 Total $ 8,295,361 $ 231,672 $ 1,318,294 $ 23,077 $ 9,868,404 The table below provides a consolidated reconciliation of the beginning and ending liability for losses and LAE: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 10,593,436 $ 9,354,891 $ 9,868,404 $ 9,048,796 Less: reinsurance reserves recoverable 1,858,161 1,873,766 1,927,624 1,708,272 Less: deferred charge assets on retroactive reinsurance 258,516 99,094 272,462 86,585 Less: cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible reinsurance balances (1) — — 643 — Net balance as of beginning of period 8,476,759 7,382,031 7,667,675 7,253,939 Net incurred losses and LAE: Current period 78,965 156,344 314,083 457,720 Prior periods 30,721 6,914 25,595 108,391 Total net incurred losses and LAE 109,686 163,258 339,678 566,111 Net paid losses: Current period (17,194) (36,733) (32,304) (107,679) Prior periods (344,060) (397,514) (1,070,063) (1,255,903) Total net paid losses (361,254) (434,247) (1,102,367) (1,363,582) Effect of exchange rate movement 99,129 (83,277) (6,139) (95,270) Acquired on purchase of subsidiaries — — — 686 Assumed business 280,497 445,000 1,705,970 1,110,881 Reclassification to assets and liabilities held-for-sale (219,284) — (219,284) — Net balance as of September 30 8,385,533 7,472,765 8,385,533 7,472,765 Plus: reinsurance reserves recoverable (2) 1,667,151 1,876,613 1,667,151 1,876,613 Plus: deferred charge assets on retroactive reinsurance 248,200 167,268 248,200 167,268 Balance as of September 30 $ 10,300,884 $ 9,516,646 $ 10,300,884 $ 9,516,646 (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. This amount excludes $0.4 million related to the adoption impact of ASU 2016-13 (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 September 30, 2020 Non-life Run-off Atrium StarStone Other Total Net losses paid $ 283,882 $ 17,189 $ 56,727 $ 3,456 $ 361,254 Net change in case and LAE reserves (49,887) 2,701 5,456 103 (41,627) Net change in IBNR reserves (221,800) 2,386 (8,579) 1,484 (226,509) Increase in estimates of net ultimate losses 12,195 22,276 53,604 5,043 93,118 Reduction in provisions for unallocated LAE (14,605) (29) (5,020) — (19,654) Amortization of deferred charge assets 10,316 — — — 10,316 Amortization of fair value adjustments 5,310 (252) (194) — 4,864 Changes in fair value - fair value option 21,042 — — — 21,042 Net incurred losses and LAE $ 34,258 $ 21,995 $ 48,390 $ 5,043 $ 109,686 Three Months Ended September 30, 2019 Non-life Atrium StarStone Other Total Net losses paid $ 288,445 $ 20,005 $ 122,848 $ 2,949 $ 434,247 Net change in case and LAE reserves (173,104) (91) (17,860) 944 (190,111) Net change in IBNR reserves (148,521) 8,702 (4,713) (246) (144,778) Increase (reduction) in estimates of net ultimate losses (33,180) 28,616 100,275 3,647 99,358 Reduction in provisions for unallocated LAE (12,158) — (188) — (12,346) Amortization of deferred charge assets 17,009 — — — 17,009 Amortization of fair value adjustments 17,538 (216) 541 — 17,863 Changes in fair value - fair value option 41,374 — — — 41,374 Net incurred losses and LAE $ 30,583 $ 28,400 $ 100,628 $ 3,647 $ 163,258 Nine Months Ended September 30, 2020 Non-life Run-off Atrium StarStone Other Total Net losses paid $ 826,250 $ 48,416 $ 218,200 $ 9,501 $ 1,102,367 Net change in case and LAE reserves (300,573) 3,635 (60,887) 965 (356,860) Net change in IBNR reserves (581,979) 14,227 17,032 2,252 (548,468) Increase (reduction) in estimates of net ultimate losses (56,302) 66,278 174,345 12,718 197,039 Increase (reduction) in provisions for unallocated LAE (34,509) (29) 23,475 — (11,063) Amortization of deferred charge assets 36,008 — — — 36,008 Amortization of fair value adjustments 21,653 (246) (561) — 20,846 Changes in fair value - fair value option 96,848 — — — 96,848 Net incurred losses and LAE $ 63,698 $ 66,003 $ 197,259 $ 12,718 $ 339,678 Nine Months Ended September 30, 2019 Non-life Atrium StarStone Other Total Net losses paid $ 966,617 $ 60,095 $ 329,265 $ 7,605 $ 1,363,582 Net change in case and LAE reserves (370,639) (245) 13,508 2,298 (355,078) Net change in IBNR reserves (619,648) (1,916) 15,042 3,165 (603,357) Increase (reduction) in estimates of net ultimate losses (23,670) 57,934 357,815 13,068 405,147 Increase (reduction) in provisions for unallocated LAE (38,229) — 739 — (37,490) Amortization of deferred charge assets 28,006 — — — 28,006 Amortization of fair value adjustments 34,033 728 310 — 35,071 Changes in fair value - fair value option 135,377 — — — 135,377 Net incurred losses and LAE $ 135,517 $ 58,662 $ 358,864 $ 13,068 $ 566,111 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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 8,979,234 $ 7,803,663 $ 8,295,361 $ 7,540,662 Less: reinsurance reserves recoverable 1,429,489 1,534,427 1,543,614 1,366,123 Less: deferred charge assets on retroactive insurance 258,516 99,094 272,462 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 7,291,229 6,170,142 6,479,988 6,087,954 Net incurred losses and LAE: Current period 8,218 23,845 24,153 107,291 Prior periods 26,040 6,738 39,545 28,226 Total net incurred losses and LAE 34,258 30,583 63,698 135,517 Net paid losses: Current period (739) (14,374) (1,777) (53,265) Prior periods (283,143) (274,071) (824,473) (913,352) Total net paid losses (283,882) (288,445) (826,250) (966,617) Effect of exchange rate movement 86,047 (73,231) (15,257) (84,372) Acquired on purchase of subsidiaries — — — 686 Assumed business 280,497 445,000 1,705,970 1,110,881 Reclassification to assets and liabilities held-for-sale — — — — Net balance as of September 30 7,408,149 6,284,049 7,408,149 6,284,049 Plus: reinsurance reserves recoverable (2) 1,267,241 1,488,374 1,267,241 1,488,374 Plus: deferred charge assets on retroactive reinsurance 248,200 167,268 248,200 167,268 Balance as of September 30 $ 8,923,590 $ 7,939,691 $ 8,923,590 $ 7,939,691 (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 September 30, 2020 2019 Prior Current Total Prior Current Total Net losses paid $ 283,143 $ 739 $ 283,882 $ 274,071 $ 14,374 $ 288,445 Net change in case and LAE reserves (49,854) (33) (49,887) (175,830) 2,726 (173,104) Net change in IBNR reserves (229,312) 7,512 (221,800) (155,315) 6,794 (148,521) Increase (reduction) in estimates of net ultimate losses 3,977 8,218 12,195 (57,074) 23,894 (33,180) Reduction in provisions for unallocated LAE (14,605) — (14,605) (12,109) (49) (12,158) Amortization of deferred charge assets 10,316 — 10,316 17,009 — 17,009 Amortization of fair value adjustments 5,310 — 5,310 17,538 — 17,538 Changes in fair value - fair value option 21,042 — 21,042 41,374 — 41,374 Net incurred losses and LAE $ 26,040 $ 8,218 $ 34,258 $ 6,738 $ 23,845 $ 30,583 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 September 30, 2020 The increase in net incurred losses and LAE for the three months ended September 30, 2020 of $34.3 million included net incurred losses and LAE of $8.2 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 $8.2 million, the increase in net incurred losses and LAE relating to prior periods was $26.0 million, which was primarily attributable to an increase in the fair value of liabilities of $21.0 million related to our assumed retroactive reinsurance agreements for which we have elected the fair value option primarily due to narrowing credit spreads on corporate bond yields in the period, amortization of the deferred charge assets of $10.3 million, amortization of fair value adjustments over the estimated payout period relating to companies acquired of $5.3 million, and an increase in estimates of net ultimate losses of $4.0 million, partially offset by a reduction in provisions for unallocated LAE of $14.6 million relating to 2020 run-off activity. Net ultimate losses relating to prior periods were relatively unchanged with an increase in estimates of net ultimate losses of $4.0 million for the three months ended September 30, 2020 and included net losses paid of $283.1 million, partially offset by a net reduction in case and IBNR reserves of $279.2 million. Unfavorable development of approximately $128.4 million within our motor line of business, was offset by favorable development across workers compensation and other lines of business. Three Months Ended September 30, 2019 Net incurred losses and LAE for the three months ended September 30, 2019 of $30.6 million included net incurred losses and LAE of $23.8 million related to current period net earned premium, primarily for the run-off business acquired 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 $23.8 million, the increase in net incurred losses and LAE relating to prior periods was $6.7 million, which was attributable to an increase in the fair value of liabilities of $41.4 million related to our assumed retroactive reinsurance agreements for which we have elected the fair value option primarily as a result of a decrease in corporate bond yields, amortization of fair value adjustments over the estimated payout period relating to companies acquired of $17.5 million and amortization of the deferred charge assets of $17.0 million, partially offset by a reduction in estimates of net ultimate losses of $57.1 million and a reduction in provisions for unallocated LAE of $12.1 million relating to 2019 run-off activity. The reduction in estimates of net ultimate losses relating to prior periods of $57.1 million for the three months ended September 30, 2019 included a net reduction in case and IBNR reserves of $331.1 million, partially offset by net losses paid of $274.1 million. Nine Months Ended September 30, 2020 2019 Prior Current Total Prior Current Total Net losses paid $ 824,473 $ 1,777 $ 826,250 $ 913,352 $ 53,265 $ 966,617 Net change in case and LAE reserves (301,382) 809 (300,573) (394,780) 24,141 (370,639) Net change in IBNR reserves (603,546) 21,567 (581,979) (649,053) 29,405 (619,648) Increase (reduction) in estimates of net ultimate losses (80,455) 24,153 (56,302) (130,481) 106,811 (23,670) Increase (reduction) in provisions for unallocated LAE (34,509) — (34,509) (38,709) 480 (38,229) Amortization of deferred charge assets 36,008 — 36,008 28,006 — 28,006 Amortization of fair value adjustments 21,653 — 21,653 34,033 — 34,033 Changes in fair value - fair value option 96,848 — 96,848 135,377 — 135,377 Net incurred losses and LAE $ 39,545 $ 24,153 $ 63,698 $ 28,226 $ 107,291 $ 135,517 Nine Months Ended September 30, 2020 The increase in net incurred losses and LAE for the nine months ended September 30, 2020 of $63.7 million included net incurred losses and LAE of $24.2 million related to current period net earned premium, primarily for the run-off business acquired with the AmTrust RITC transactions. Excluding current period net incurred losses and LAE of $24.2 million, the increase in net incurred losses and LAE liabilities relating to prior periods was $39.5 million, which was attributable to an increase in the fair value of liabilities of $96.8 million related to our assumed retroactive reinsurance agreements for which we have elected the fair value option primarily due to declining interest rates on corporate bond yields in the period, amortization of the deferred charge assets of $36.0 million and amortization of fair value adjustments over the estimated payout period relating to companies acquired of $21.7 million, partially offset by a reduction in estimates of net ultimate losses of $80.5 million and a reduction in provisions for unallocated LAE of $34.5 million relating to 2020 run-off activity. For the nine months ended September 30, 2020, the change in net ultimate losses relating to prior periods was favorable with a reduction of $80.5 million, which included a net change in case and IBNR reserves of $904.9 million, partially offset by net losses paid of $824.5 million. The favorable development was largely attributed to workers compensation as well as other lines of business, partially offset by unfavorable development of $122.4 million within our motor line of business. Nine Months Ended September 30, 2019 The increase in net incurred losses and LAE for the nine months ended September 30, 2019 of $135.5 million included net incurred losses and LAE of $107.3 million related to current period net earned premium, primarily for the run-off business acquired with the AmTrust RITC transactions and the acquisition of Maiden Re North America. Excluding current period net incurred losses and LAE of $107.3 million, the increase in net incurred losses and LAE liabilities relating to prior periods was $28.2 million, which was attributable to an increase in the fair value of liabilities of $135.4 million related to our assumed retroactive reinsurance agreements for which we have elected the fair value option primarily as a result of a decrease in corporate bond yields, amortization of fair value adjustments over the estimated payout period relating to companies acquired of $34.0 million and amortization of the deferred charge assets of $28.0 million, partially offset by a reduction in estimates of net ultimate losses of $130.5 million and a reduction in provisions for unallocated LAE of $38.7 million relating to 2019 run-off activity. The reduction in estimates of net ultimate losses of $130.5 million for the nine months ended September 30, 2019 included a net change in case and IBNR reserves of $1,043.8 million, partially offset by net losses paid of $913.4 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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 239,731 $ 222,576 $ 231,672 $ 241,284 Less: reinsurance reserves recoverable 27,250 29,606 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 212,481 192,970 202,005 202,516 Net incurred losses and LAE: Current period 23,129 27,093 70,075 63,189 Prior periods (1,134) 1,307 (4,072) (4,527) Total net incurred losses and LAE 21,995 28,400 66,003 58,662 Net paid losses: Current period (7,717) (9,387) (17,004) (24,531) Prior periods (9,472) (10,618) (31,412) (35,564) Total net paid losses (17,189) (20,005) (48,416) (60,095) Effect of exchange rate movement 1,997 (1,405) (308) (1,123) Reclassification to assets and liabilities held-for-sale (219,284) — (219,284) — Net balance as of September 30 — 199,960 — 199,960 Plus: reinsurance reserves recoverable (2) — 31,719 — 31,719 Balance as of September 30 $ — $ 231,679 $ — $ 231,679 (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 September 30, 2020 2019 Prior Current Total Prior Current Total Net losses paid $ 9,472 $ 7,717 $ 17,189 $ 10,618 $ 9,387 $ 20,005 Net change in case and LAE reserves (2,292) 4,993 2,701 (2,860) 2,769 (91) Net change in IBNR reserves (8,110) 10,496 2,386 (6,235) 14,937 8,702 Increase (reduction) in estimates of net ultimate losses (930) 23,206 22,276 1,523 27,093 28,616 Increase (reduction) in provisions for unallocated LAE 48 (77) (29) — — — Amortization of fair value adjustments (252) — (252) (216) — (216) Net incurred losses and LAE $ (1,134) $ 23,129 $ 21,995 $ 1,307 $ 27,093 $ 28,400 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 September 30, 2020 and 2019 Net incurred losses and LAE for the three months ended September 30, 2020 and 2019 were $22.0 million and $28.4 million, respectively. Net favorable prior period loss development was $1.1 million for the three months ended September 30, 2020 compared to net unfavorable prior period loss development of $1.3 million for the three months ended September 30, 2019. Excluding prior period loss development, net incurred losses and LAE for the three months ended September 30, 2020 were $23.1 million and included $1.5 million of losses related to the COVID-19 pandemic. Excluding prior period loss development, net incurred losses and LAE for the three months ended September 30, 2019 were $27.1 million. Nine Months Ended September 30, 2020 2019 Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 31,412 $ 17,004 $ 48,416 $ 35,564 $ 24,531 $ 60,095 Net change in case and LAE reserves (9,517) 13,152 3,635 (13,032) 12,787 (245) Net change in IBNR reserves (25,769) 39,996 14,227 (27,787) 25,871 (1,916) Increase (reduction) in estimates of net ultimate losses (3,874) 70,152 66,278 (5,255) 63,189 57,934 Increase (reduction) in provisions for unallocated LAE 48 (77) (29) — — — Amortization of fair value adjustments (246) — (246) 728 — 728 Net incurred losses and LAE $ (4,072) $ 70,075 $ 66,003 $ (4,527) $ 63,189 $ 58,662 Nine Months Ended September 30, 2020 and 2019 Net incurred losses and LAE for the nine months ended September 30, 2020 and 2019 were $66.0 million and $58.7 million, respectively. Net favorable prior year loss development was $4.1 million and $4.5 million for the nine months ended September 30, 2020 and 2019, respectively. The current period net favorable prior period loss development was driven by favorable development across several lines of business. Excluding prior period loss development, net incurred losses and LAE for the nine months ended September 30, 2020 were $70.1 million and included $14.3 million of losses related to the COVID-19 pandemic. Excluding prior period loss development, net incurred losses and LAE for the nine months ended September 30, 2019 were $63.2 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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 1,349,763 $ 1,305,026 $ 1,318,294 $ 1,247,989 Less: reinsurance reserves recoverable 401,422 309,733 355,194 303,381 Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance (1) — — 495 — Net balance as of beginning of period 948,341 995,293 962,605 944,608 Net incurred losses and LAE: Current period 44,734 101,808 208,414 274,070 Prior periods 3,656 (1,180) (11,155) 84,794 Total net incurred losses and LAE 48,390 100,628 197,259 358,864 Net paid losses: Current period (7,755) (11,653) (12,142) (27,624) Prior periods (48,972) (111,195) (206,058) (301,641) Total net paid losses (56,727) (122,848) (218,200) (329,265) Effect of exchange rate movement 11,084 (8,641) 9,424 (9,775) Net balance as of September 30 951,088 964,432 951,088 964,432 Plus: reinsurance reserves recoverable (2) 399,910 356,520 399,910 356,520 Balance as of September 30 $ 1,350,998 $ 1,320,952 $ 1,350,998 $ 1,320,952 (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. This amount excludes $0.4 million related to the adoption impact of ASU 2016-13 (2) Net of allowance for estimated uncollectible reinsurance. Net incurred losses and LAE in the StarStone segment were as follows: Three Months Ended September 30, 2020 2019 Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 48,972 $ 7,755 $ 56,727 $ 111,195 $ 11,653 $ 122,848 Net change in case and LAE reserves (20,068) 25,524 5,456 (8,866) (8,994) (17,860) Net change in IBNR reserves (24,755) 16,176 (8,579) (101,938) 97,225 (4,713) Increase in estimates of net ultimate losses 4,149 49,455 53,604 391 99,884 100,275 Increase (reduction) in provisions for unallocated LAE (299) (4,721) (5,020) (2,112) 1,924 (188) Amortization of fair value adjustments (194) — (194) 541 — 541 Net incurred losses and LAE $ 3,656 $ 44,734 $ 48,390 $ (1,180) $ 101,808 $ 100,628 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 September 30, 2020 and 2019 Net incurred losses and LAE for the three months ended September 30, 2020 and 2019 were $48.4 million and $100.6 million, respectively. Net unfavorable prior period loss development was $3.7 million for the three months ended September 30, 2020 compared to net favorable prior period loss development of $1.2 million for the three months ended September 30, 2019. Net unfavorable prior period loss development for the three months Nine Months Ended September 30, 2020 2019 Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 206,058 $ 12,142 $ 218,200 $ 301,641 $ 27,624 $ 329,265 Net change in case and LAE reserves (85,798) 24,911 (60,887) (22,538) 36,046 13,508 Net change in IBNR reserves (130,738) 147,770 17,032 (192,034) 207,076 15,042 Increase (reduction) in estimates of net ultimate losses (10,478) 184,823 174,345 87,069 270,746 357,815 Increase (reduction) in provisions for unallocated LAE (116) 23,591 23,475 (2,585) 3,324 739 Amortization of fair value adjustments (561) — (561) 310 — 310 Net incurred losses and LAE $ (11,155) $ 208,414 $ 197,259 $ 84,794 $ 274,070 $ 358,864 Nine Months Ended September 30, 2020 and 2019 Net incurred losses and LAE for the nine months ended September 30, 2020 and 2019 were $197.3 million and $358.9 million, respectively. Net favorable prior period loss development was $11.2 million for the nine months ended September 30, 2020 compared to net unfavorable prior period loss development of $84.8 million for the nine months ended September 30, 2019. Net favorable prior period loss development for the nine months ended September 30, 2020 was driven by favorable development in the workers compensation and casualty lines of business. Net unfavorable prior period loss development for the nine months ended September 30, 2019 was primarily related to development on lines of business that we had either exited or had been subject to remediation as part of our underwriting repositioning initiatives before our decision to place StarStone International into run-off. Excluding prior period loss development, net incurred losses and LAE for the nine months ended September 30, 2020 were $208.4 million and included $22.8 million of COVID-19 related losses and $23.7 million of exit costs associated with the StarStone International Run-Off. Excluding prior period loss development, net incurred losses and LAE for the nine months ended September 30, 2019 were $274.1 million.

Defendant Asbestos and Environm

Defendant Asbestos and Environmental Liabilities	9 Months Ended
	Sep. 30, 2020
Liability for Asbestos and Environmental Claims [Abstract]
DEFENDANT ASBESTOS AND ENVIRONMENTAL LIABILITIES	10. 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. 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. 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 September 30, 2020 and December 31, 2019 were as follows: September 30, 2020 December 31, 2019 Defendant asbestos and environmental liabilities: Defendant asbestos liabilities $ 980,678 $ 1,100,593 Defendant environmental liabilities 8,214 10,279 Estimated future expenses 45,509 51,637 Fair value adjustments (280,364) (314,824) Defendant asbestos and environmental liabilities $ 754,037 $ 847,685 Insurance balances recoverable: Insurance recoveries related to defendant asbestos and environmental liabilities (net of allowance: 2020 - $5,907) 447,800 549,593 Fair value adjustments (82,512) (100,738) Insurance balances recoverable $ 365,288 $ 448,855 Net liabilities relating to defendant asbestos and environmental exposures $ 388,749 $ 398,830 The table below provides a consolidated reconciliation of the beginning and ending liability for defendant asbestos and environmental exposures for the three and nine months ended September 30, 2020 and 2019: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 808,062 $ 184,264 $ 847,685 $ 203,320 Less: Insurance balances recoverable 428,277 122,236 448,855 135,808 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 379,785 62,028 401,997 67,512 Total net paid claims 52,891 (2,204) 51,977 (1,326) Amounts recorded in other (income) expense: Reduction in estimates of ultimate net liabilities (48,439) — (75,332) (4,259) Reduction in estimated future expenses (3,124) (800) (6,127) (3,104) Amortization of fair value adjustments 7,636 102 16,234 303 Total other (income) expense (43,927) (698) (65,225) (7,060) Net balance as at September 30 388,749 59,126 388,749 59,126 Plus: Insurance balances recoverable (2) 365,288 121,237 365,288 121,237 Balance as at September 30 $ 754,037 $ 180,363 $ 754,037 $ 180,363 (1) The Company adopted ASU 2016-13 (2) Net of allowance for estimated uncollectible insurance balances. 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. 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 use the PD and LGD methodology as described in Note 7 - "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 and nine months ended September 30, 2020: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Allowance for estimated uncollectible insurance balances, beginning of period $ 8,346 $ 3,818 Cumulative effect of change in accounting principle — 3,167 Current period change in the allowance (2,439) (1,078) Allowance for estimated uncollectible insurance balances, end of period $ 5,907 $ 5,907 During the three and nine months ended September 30, 2020, we did not have any write-offs charged against the allowance for estimated uncollectible insurance or any recoveries of amounts previously written off. We did not have significant past due balances receivable from our insurers related to our defendant asbestos liabilities, that were older than one year for any of the periods presented.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	11. 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: September 30, 2020 Quoted Prices in Significant Significant Fair Value Based on NAV as Practical Expedient Total Fair Investments: Short-term and fixed maturity investments: U.S. government and agency $ — $ 789,630 $ — $ — $ 789,630 U.K. government — 114,777 — — 114,777 Other government — 490,447 — — 490,447 Corporate — 5,679,909 — — 5,679,909 Municipal — 161,839 — — 161,839 Residential mortgage-backed — 529,239 — — 529,239 Commercial mortgage-backed — 843,119 — — 843,119 Asset-backed — 613,663 — — 613,663 $ — $ 9,222,623 $ — $ — $ 9,222,623 Other assets included within funds held - directly managed — 12,438 — — 12,438 Equities: Publicly traded equity investments $ 282,904 $ 21,028 $ — $ — $ 303,932 Exchange-traded funds 78,182 — — — 78,182 Privately held equity investments — — 271,045 — 271,045 $ 361,086 $ 21,028 $ 271,045 $ — $ 653,159 Other investments: Hedge funds $ — $ — $ — $ 2,087,091 $ 2,087,091 Fixed income funds — 428,645 — 255,386 684,031 Equity funds — 4,558 — 285,571 290,129 Private equity funds — — — 320,455 320,455 CLO equities — 84,532 — — 84,532 CLO equity funds — — — 140,458 140,458 Private credit funds — — 10,000 80,476 90,476 Other — — 314 7,384 7,698 $ — $ 517,735 $ 10,314 $ 3,176,821 $ 3,704,870 Total Investments $ 361,086 $ 9,773,824 $ 281,359 $ 3,176,821 $ 13,593,090 Cash and cash equivalents $ 270,267 $ 139,140 $ — $ — $ 409,407 Reinsurance balances recoverable on paid and unpaid losses: $ — $ — $ 543,161 $ — $ 543,161 Other Assets: Derivatives qualifying as hedges $ — $ 6,785 $ — $ — $ 6,785 Derivatives not qualifying as hedges — 1,526 — — 1,526 Derivative instruments $ — $ 8,311 $ — $ — $ 8,311 Losses and LAE: $ — $ — $ 2,422,678 $ — $ 2,422,678 Other Liabilities: Derivatives qualifying as hedges $ — $ — $ — $ — $ — Derivatives not qualifying as hedges — 585 — — 585 Derivative instruments $ — $ 585 $ — $ — $ 585 December 31, 2019 Quoted Prices in Significant Significant Fair Value Based on NAV as Practical Expedient Total Fair Investments: Short-term and fixed maturity investments: U.S. government and agency $ — $ 696,077 $ — $ — $ 696,077 U.K government — 161,772 — — 161,772 Other government — 702,856 — — 702,856 Corporate — 5,448,270 — — 5,448,270 Municipal — 140,687 — — 140,687 Residential mortgage-backed — 400,914 — — 400,914 Commercial mortgage-backed — 813,746 — — 813,746 Asset-backed — 670,235 — — 670,235 $ — $ 9,034,557 $ — $ — $ 9,034,557 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 — — 265,799 — 265,799 $ 430,357 $ 30,565 $ 265,799 $ — $ 726,721 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 — — — 323,496 323,496 CLO equities — — 87,555 — 87,555 CLO equity funds — — — 87,509 87,509 Other — 34 314 6,031 6,379 $ — $ 509,217 $ 87,869 $ 1,920,945 $ 2,518,031 Total Investments $ 430,357 $ 9,588,546 $ 353,668 $ 1,920,945 $ 12,293,516 Cash and cash equivalents $ 144,984 $ 222,191 $ — $ — $ 367,175 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 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. 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 derivative instruments, as described in Note 6 - "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 September 30, 2020 Privately-held Equities Other Investments Total Beginning fair value $ 271,000 $ 314 $ 271,314 Purchases — 10,000 10,000 Sales — — — Total realized and unrealized gains 45 — 45 Transfer out of Level 3 into Level 2 — — — Ending fair value $ 271,045 $ 10,314 $ 281,359 Three Months Ended September 30, 2019 Fixed maturity investments Privately-held Equities Other Investments Total Corporate Residential mortgage-backed Commercial mortgage-backed Asset-backed Beginning fair value $ 5,006 $ 102 $ 1,370 $ 25,839 $ 229,394 $ 50,452 $ 312,163 Purchases 82 — — — 3,691 22,619 26,392 Sales (116) — (176) (295) (2,016) (361) (2,964) Total realized and unrealized gains (losses) (103) (1) 148 (743) (2,378) (5,287) (8,364) Transfer into Level 3 from Level 2 277 — — — — — 277 Transfer out of Level 3 into Level 2 (2,865) (101) (1,340) (5,978) — — (10,284) Ending fair value $ 2,281 $ — $ 2 $ 18,823 $ 228,691 $ 67,423 $ 317,220 Nine Months Ended September 30, 2020 Privately-held Equities Other Investments Total Beginning fair value $ 265,799 $ 87,869 $ 353,668 Purchases 1,392 47,092 48,484 Sales — (539) (539) Total realized and unrealized gains (losses) 3,854 (40,368) (36,514) Transfer into Level 3 from Level 2 — — — Transfer out of Level 3 into Level 2 — (83,740) (83,740) Ending fair value $ 271,045 $ 10,314 $ 281,359 Nine Months Ended September 30, 2019 Fixed maturity investments Privately-held Equities Other Investments Total Corporate Residential mortgage-backed Commercial mortgage-backed Asset-backed Beginning fair value $ 37,386 $ — $ 7,389 $ 9,121 $ 228,710 $ 39,367 $ 321,973 Purchases 172 — — — 3,691 34,614 38,477 Sales (3,157) — (784) (625) (2,016) (361) (6,943) Total realized and unrealized gains (losses) 114 (1) 65 (4) (1,694) (6,197) (7,717) Transfer into Level 3 from Level 2 3,535 102 1,515 22,771 — — 27,923 Transfer out of Level 3 into Level 2 (35,769) (101) (8,183) (12,440) — — (56,493) Ending fair value $ 2,281 $ — $ 2 $ 18,823 $ 228,691 $ 67,423 $ 317,220 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 our privately held equity investments measured at fair value on a recurring basis using Level 3 inputs: Quantitative Information about Level 3 Fair Value Measurements Fair Value as of September 30, 2020 Valuation Techniques Unobservable Input Range (Average) (1) (in millions of U.S. dollars) $ 245.4 Transactional value Implied price per share at recent purchase transaction 13.50 - 13.85 $ 25.6 Cost as approximation of fair value Cost as approximation of fair value $ 271.0 (1) The average represents the arithmetic average of the inputs and is not weighted by the relative fair value. 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 September 30, 2020 2019 Liability for losses and LAE Reinsurance balances recoverable Net Liability for losses and LAE Reinsurance balances recoverable Net Beginning fair value $ 2,454,539 $ 671,384 $ 1,783,155 $ 2,772,501 $ 743,304 $ 2,029,197 Assumed business 1,526 (180,972) 182,498 — — — Incurred losses and LAE: Reduction in estimates of ultimate losses (25,595) 56,702 (82,297) (7,386) 2,354 (9,740) Reduction in unallocated LAE (4,641) — (4,641) (6,724) — (6,724) Change in fair value 19,092 (1,950) 21,042 57,743 16,369 41,374 Total incurred losses and LAE (11,144) 54,752 (65,896) 43,633 18,723 24,910 Paid losses (86,745) (11,192) (75,553) (100,654) (21,816) (78,838) Effect of exchange rate movements 64,502 9,189 55,313 (56,836) (8,307) (48,529) Ending fair value $ 2,422,678 $ 543,161 $ 1,879,517 $ 2,658,644 $ 731,904 $ 1,926,740 The net assumed business of $182.5 million in the current period relates to the Hannover Re novation transaction disclosed in Note 3 - "Significant New Business." 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 2020 2019 Changes in fair value due to changes in: Duration $ 11,767 $ 3,850 Corporate bond yield 9,275 37,524 Change in fair value $ 21,042 $ 41,374 Nine Months Ended 2020 2019 Liability for losses and LAE Reinsurance balances recoverable on paid and unpaid losses Net Liability for losses and LAE Reinsurance balances recoverable on paid and unpaid losses Net Beginning fair value $ 2,621,122 $ 695,518 $ 1,925,604 $ 2,874,055 $ 739,591 $ 2,134,464 Assumed business 1,526 (180,972) 182,498 — — — Incurred losses and LAE: Reduction in estimates of ultimate losses (61,109) 48,580 (109,689) (20,342) 4,059 (24,401) Reduction in unallocated LAE (14,353) — (14,353) (15,076) — (15,076) Change in fair value 130,075 33,227 96,848 189,422 54,045 135,377 Total incurred losses and LAE 54,613 81,807 (27,194) 154,004 58,104 95,900 Paid losses (230,187) (49,627) (180,560) (308,267) (58,139) (250,128) Effect of exchange rate movements (24,396) (3,565) (20,831) (61,148) (7,652) (53,496) Ending fair value $ 2,422,678 $ 543,161 $ 1,879,517 $ 2,658,644 $ 731,904 $ 1,926,740 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: Nine Months Ended 2020 2019 Changes in fair value due to changes in: Duration $ 19,617 $ 18,736 Corporate bond yield 75,524 116,641 Weighted cost of capital (5,048) — Risk cost of capital 6,755 — Change in fair value $ 96,848 $ 135,377 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: September 30, 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) 7.92 years 7.82 years Internal model Duration - reinsurance balances recoverable (U) 7.71 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 September 30, 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 $349.2 million and $493.9 million, respectively, while the fair value based on observable market pricing from a third party pricing service was $363.2 million and $556.8 million, respectively. The Senior Notes are classified as Level 2. Junior Subordinated Notes As of September 30, 2020, our 5.75% Fixed-Rate Reset Junior Subordinated Notes due 2040 (the “Junior Subordinated Notes”) were carried at amortized cost of $344.8 million, while the fair value based on observable market pricing from a third party pricing service was $357.7 million. The Junior Subordinated 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 September 30, 2020 and December 31, 2019.

Premiums Written and Earned

Premiums Written and Earned	9 Months Ended
	Sep. 30, 2020
Insurance [Abstract]
PREMIUMS WRITTEN AND EARNED	$1 million 556,623 132,049 688,672 36.6 % Other reinsurers < $1 million 18,687 1,374 20,061 1.1 % Total $ 1,403,789 $ 477,867 $ 1,881,656 100.0 % December 31, 2019 Non-life Atrium StarStone Total % of Top 10 reinsurers $ 1,154,110 $ 22,051 $ 295,443 $ 1,471,604 67.4 % Other reinsurers > $1 million 551,636 7,761 129,335 688,732 31.6 % Other reinsurers < $1 million 19,243 545 1,010 20,798 1.0 % Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 100.0 % September 30, 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 $ 910,751 $ 1,199,479 Non-rated reinsurers in top 10 (1) 262,172 272,125 Total top 10 reinsurance recoverables $ 1,172,923 $ 1,471,604 Single reinsurers that represent 10% or more of total reinsurance balance recoverables as of September 30, 2020: Hannover Ruck SE (2) $ — $ 259,077 Lloyd's Syndicates (3) $ 346,601 $ 396,246 (1) The reinsurance balances recoverable from the two non-rated top 10 reinsurers was comprised of: • $183.4 million and $190.8 million as of September 30, 2020 and December 31, 2019 respectively, due from a US state backed reinsurer that is supported by assessments on active auto writers operating within the state; and • $78.8 million and $81.4 million as of September 30, 2020 and December 31, 2019 respectively, due from a reinsurer who has provided us with security in the form of pledged assets in trust for the full amount of the recoverable balance. (2) Hannover Ruck SE is rated AA- by Standard & Poor’s and A+ by A.M. Best. The transaction described in Note 3 - "Significant New Business" had the effect of moving this reinsurer to be less than 10%. (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 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. September 30, 2020 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,429,984 $ 57,465 $ 1,372,519 4.0 % Reinsurers rated below A-, secured 419,431 — 419,431 — % Reinsurers rated below A-, unsecured 167,358 77,652 89,706 46.4 % Total $ 2,016,773 $ 135,117 $ 1,881,656 6.7 % December 31, 2019 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,731,270 $ 43,427 $ 1,687,843 2.5 % Reinsurers rated below A-, secured 463,840 — 463,840 — % Reinsurers rated below A-, unsecured 133,663 104,212 29,451 78.0 % Total $ 2,328,773 $ 147,639 $ 2,181,134 6.3 % The table below provides a reconciliation of the beginning and ending allowance for estimated uncollectible reinsurance balances for the three and nine months ended September 30, 2020: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Allowance for estimated uncollectible reinsurance, beginning of period $ 143,653 $ 147,639 Cumulative effect of change in accounting principle — (195) Effect of exchange rate movement 745 (701) Current period change in the allowance 815 (718) Write-offs charged against the allowance (9,625) (10,225) Recoveries collected (471) (683) Allowance for estimated uncollectible reinsurance, end of period $ 135,117 $ 135,117 Past-Due Status: We consider a reinsurance recoverable asset to be past due when it is 90 days past due and record a credit allowance when there is reasonable uncertainty about the collectability of a disputed amount during the reporting period. We did not have significant past due balances older than one year for any of the periods presented. 12. 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Premiums Premiums Premiums Premiums Premiums Premiums Premiums Premiums Non-life Run-off Gross $ 3,535 $ 20,426 $ 301 $ 27,190 $ 1,707 $ 52,899 $ (24,785) $ 166,707 Ceded (111) (2,950) (4,109) (10,353) 690 (8,876) (1,610) (24,726) Net $ 3,424 $ 17,476 $ (3,808) $ 16,837 $ 2,397 $ 44,023 $ (26,395) $ 141,981 Atrium Gross $ 49,083 $ 48,690 $ 48,746 $ 48,340 $ 155,551 $ 144,675 $ 146,519 $ 133,610 Ceded (2,580) (6,264) (4,961) (5,427) (19,458) (16,492) (19,273) (13,745) Net $ 46,503 $ 42,426 $ 43,785 $ 42,913 $ 136,093 $ 128,183 $ 127,246 $ 119,865 StarStone Gross $ 58,566 $ 123,813 $ 110,586 $ 151,895 $ 300,135 $ 362,638 $ 363,352 $ 409,135 Ceded (15,228) (27,697) (34,566) (40,146) (73,069) (86,072) (72,269) (69,142) Net $ 43,338 $ 96,116 $ 76,020 $ 111,749 $ 227,066 $ 276,566 $ 291,083 $ 339,993 Other Gross $ 293 $ 5,705 $ (2,498) $ 4,338 $ 3,237 $ 15,173 $ (1,174) $ 17,024 Ceded 1 1 (5) (35) 1 1 (23) (152) Net $ 294 $ 5,706 $ (2,503) $ 4,303 $ 3,238 $ 15,174 $ (1,197) $ 16,872 Total Gross $ 111,477 $ 198,634 $ 157,135 $ 231,763 $ 460,630 $ 575,385 $ 483,912 $ 726,476 Ceded (17,918) (36,910) (43,641) (55,961) (91,836) (111,439) (93,175) (107,765) Total $ 93,559 $ 161,724 $ 113,494 $ 175,802 $ 368,794 $ 463,946 $ 390,737 $ 618,711 Gross premiums written for the three months ended September 30, 2020 and 2019 were $111.5 million and $157.1 million, respectively, a decrease of $45.7 million. The decrease was primarily due to a decrease in gross premiums written in our StarStone segment of $52.0 million, partially offset by an increase Non-life Run-off segment of $3.2 million. The decrease in the StarStone segment was due to StarStone International being placed into an orderly run-off. Gross premiums written for the nine months ended September 30, 2020 and 2019 were $460.6 million and $483.9 million, respectively, a decrease of $23.3 million. The decrease was primarily due to a decrease in gross premiums written in our StarStone segment of $63.2 million, partially offset by a reduction in negative gross premiums written in our Non-life Run-off segment of $26.5 million and an increase in the Atrium segment of $9.0 million. The decrease in the StarStone segment was primarily due to StarStone International being placed into an orderly run-off. The negative gross premium written in the Non-life Run-off segment for the nine months ended September 30, 2019 was due to premium adjustments on the acquired unearned premium primarily related to the run-off business assumed as a result of the AmTrust RITC transactions and the acquisition of Maiden Re North America. The increase in the Atrium segment was driven by increases in the binding authorities, marine, aviation and transit and non-marine direct and facultative lines of business. The binding authorities line of business benefited from new opportunities to write new business, while the marine, aviation and non-marine direct and facultative lines of business continued to benefit from an increase in rates and new opportunities in the U.S." id="sjs-B4">7. REINSURANCE BALANCES RECOVERABLE ON PAID AND UNPAID LOSSES The following tables provide the total reinsurance balances recoverable on paid and unpaid losses: September 30, 2020 Non-life StarStone Total Recoverable from reinsurers on unpaid: Outstanding losses $ 858,988 $ 258,215 $ 1,117,203 IBNR 439,594 143,073 582,667 ULAE 7,674 — 7,674 Fair value adjustments - acquired companies (11,986) (1,378) (13,364) Fair value adjustments - fair value option (27,029) — (27,029) Total reinsurance reserves recoverable 1,267,241 399,910 1,667,151 Paid losses recoverable 136,548 77,957 214,505 Total $ 1,403,789 $ 477,867 $ 1,881,656 Reconciliation to Consolidated Balance Sheet: Reinsurance balances recoverable on paid and unpaid losses $ 860,628 $ 477,867 $ 1,338,495 Reinsurance balances recoverable on paid and unpaid losses - fair value option 543,161 — 543,161 Total $ 1,403,789 $ 477,867 $ 1,881,656 December 31, 2019 Non-life Atrium StarStone Total Recoverable from reinsurers on unpaid: Outstanding losses $ 972,293 $ 9,011 $ 264,131 $ 1,245,435 IBNR 673,059 19,286 93,185 785,530 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 28,816 355,194 1,927,624 Paid losses recoverable 181,375 1,541 70,594 253,510 Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 Reconciliation to Consolidated Balance Sheet: Reinsurance balances recoverable on paid and unpaid losses $ 1,029,471 $ 30,357 $ 425,788 $ 1,485,616 Reinsurance balances recoverable on paid and unpaid losses - fair value option 695,518 — — 695,518 Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 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, StarStone purchases a tailored outwards reinsurance program designed to manage its risk profile. The majority of 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 11 - "Fair Value Measurements." As of September 30, 2020 and December 31, 2019, we had reinsurance balances recoverable on paid and unpaid losses of $1.9 billion and $2.2 billion, respectively. The decrease of $299.5 million in reinsurance balances Top Ten Reinsurers September 30, 2020 Non-life StarStone Total % of Top 10 reinsurers $ 828,479 $ 344,444 $ 1,172,923 62.3 % Other reinsurers > $1 million 556,623 132,049 688,672 36.6 % Other reinsurers < $1 million 18,687 1,374 20,061 1.1 % Total $ 1,403,789 $ 477,867 $ 1,881,656 100.0 % December 31, 2019 Non-life Atrium StarStone Total % of Top 10 reinsurers $ 1,154,110 $ 22,051 $ 295,443 $ 1,471,604 67.4 % Other reinsurers > $1 million 551,636 7,761 129,335 688,732 31.6 % Other reinsurers < $1 million 19,243 545 1,010 20,798 1.0 % Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 100.0 % September 30, 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 $ 910,751 $ 1,199,479 Non-rated reinsurers in top 10 (1) 262,172 272,125 Total top 10 reinsurance recoverables $ 1,172,923 $ 1,471,604 Single reinsurers that represent 10% or more of total reinsurance balance recoverables as of September 30, 2020: Hannover Ruck SE (2) $ — $ 259,077 Lloyd's Syndicates (3) $ 346,601 $ 396,246 (1) The reinsurance balances recoverable from the two non-rated top 10 reinsurers was comprised of: • $183.4 million and $190.8 million as of September 30, 2020 and December 31, 2019 respectively, due from a US state backed reinsurer that is supported by assessments on active auto writers operating within the state; and • $78.8 million and $81.4 million as of September 30, 2020 and December 31, 2019 respectively, due from a reinsurer who has provided us with security in the form of pledged assets in trust for the full amount of the recoverable balance. (2) Hannover Ruck SE is rated AA- by Standard & Poor’s and A+ by A.M. Best. The transaction described in Note 3 - "Significant New Business" had the effect of moving this reinsurer to be less than 10%. (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 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. September 30, 2020 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,429,984 $ 57,465 $ 1,372,519 4.0 % Reinsurers rated below A-, secured 419,431 — 419,431 — % Reinsurers rated below A-, unsecured 167,358 77,652 89,706 46.4 % Total $ 2,016,773 $ 135,117 $ 1,881,656 6.7 % December 31, 2019 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,731,270 $ 43,427 $ 1,687,843 2.5 % Reinsurers rated below A-, secured 463,840 — 463,840 — % Reinsurers rated below A-, unsecured 133,663 104,212 29,451 78.0 % Total $ 2,328,773 $ 147,639 $ 2,181,134 6.3 % The table below provides a reconciliation of the beginning and ending allowance for estimated uncollectible reinsurance balances for the three and nine months ended September 30, 2020: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Allowance for estimated uncollectible reinsurance, beginning of period $ 143,653 $ 147,639 Cumulative effect of change in accounting principle — (195) Effect of exchange rate movement 745 (701) Current period change in the allowance 815 (718) Write-offs charged against the allowance (9,625) (10,225) Recoveries collected (471) (683) Allowance for estimated uncollectible reinsurance, end of period $ 135,117 $ 135,117 Past-Due Status: We consider a reinsurance recoverable asset to be past due when it is 90 days past due and record a credit allowance when there is reasonable uncertainty about the collectability of a disputed amount during the reporting period. We did not have significant past due balances older than one year for any of the periods presented. 12. 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Premiums Premiums Premiums Premiums Premiums Premiums Premiums Premiums Non-life Run-off Gross $ 3,535 $ 20,426 $ 301 $ 27,190 $ 1,707 $ 52,899 $ (24,785) $ 166,707 Ceded (111) (2,950) (4,109) (10,353) 690 (8,876) (1,610) (24,726) Net $ 3,424 $ 17,476 $ (3,808) $ 16,837 $ 2,397 $ 44,023 $ (26,395) $ 141,981 Atrium Gross $ 49,083 $ 48,690 $ 48,746 $ 48,340 $ 155,551 $ 144,675 $ 146,519 $ 133,610 Ceded (2,580) (6,264) (4,961) (5,427) (19,458) (16,492) (19,273) (13,745) Net $ 46,503 $ 42,426 $ 43,785 $ 42,913 $ 136,093 $ 128,183 $ 127,246 $ 119,865 StarStone Gross $ 58,566 $ 123,813 $ 110,586 $ 151,895 $ 300,135 $ 362,638 $ 363,352 $ 409,135 Ceded (15,228) (27,697) (34,566) (40,146) (73,069) (86,072) (72,269) (69,142) Net $ 43,338 $ 96,116 $ 76,020 $ 111,749 $ 227,066 $ 276,566 $ 291,083 $ 339,993 Other Gross $ 293 $ 5,705 $ (2,498) $ 4,338 $ 3,237 $ 15,173 $ (1,174) $ 17,024 Ceded 1 1 (5) (35) 1 1 (23) (152) Net $ 294 $ 5,706 $ (2,503) $ 4,303 $ 3,238 $ 15,174 $ (1,197) $ 16,872 Total Gross $ 111,477 $ 198,634 $ 157,135 $ 231,763 $ 460,630 $ 575,385 $ 483,912 $ 726,476 Ceded (17,918) (36,910) (43,641) (55,961) (91,836) (111,439) (93,175) (107,765) Total $ 93,559 $ 161,724 $ 113,494 $ 175,802 $ 368,794 $ 463,946 $ 390,737 $ 618,711 Gross premiums written for the three months ended September 30, 2020 and 2019 were $111.5 million and $157.1 million, respectively, a decrease of $45.7 million. The decrease was primarily due to a decrease in gross premiums written in our StarStone segment of $52.0 million, partially offset by an increase Non-life Run-off segment of $3.2 million. The decrease in the StarStone segment was due to StarStone International being placed into an orderly run-off. Gross premiums written for the nine months ended September 30, 2020 and 2019 were $460.6 million and $483.9 million, respectively, a decrease of $23.3 million. The decrease was primarily due to a decrease in gross premiums written in our StarStone segment of $63.2 million, partially offset by a reduction in negative gross premiums written in our Non-life Run-off segment of $26.5 million and an increase in the Atrium segment of $9.0 million. The decrease in the StarStone segment was primarily due to StarStone International being placed into an orderly run-off. The negative gross premium written in the Non-life Run-off segment for the nine months ended September 30, 2019 was due to premium adjustments on the acquired unearned premium primarily related to the run-off business assumed as a result of the AmTrust RITC transactions and the acquisition of Maiden Re North America. The increase in the Atrium segment was driven by increases in the binding authorities, marine, aviation and transit and non-marine direct and facultative lines of business. The binding authorities line of business benefited from new opportunities to write new business, while the marine, aviation and non-marine direct and facultative lines of business continued to benefit from an increase in rates and new opportunities in the U.S.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	13. GOODWILL AND INTANGIBLE ASSETS The following table presents a reconciliation of the beginning and ending goodwill and intangible assets for the nine months ended September 30, 2020: Intangible assets Goodwill Intangible Intangible Total Total Balance as of December 31, 2019 $ 109,807 $ 14,630 $ 67,131 $ 81,761 $ 191,568 Impairment losses (StarStone International) (8,000) — (4,000) (4,000) (12,000) Amortization — (1,524) — (1,524) (1,524) Reclassification to assets held-for-sale (Atrium) (38,848) (13,106) (63,131) (76,237) (115,085) Balance as of September 30, 2020 $ 62,959 $ — $ — $ — $ 62,959 Goodwill The changes in the goodwill by segment were as follows for the nine months ended September 30, 2020: Non-life Atrium StarStone Total Balance as of December 31, 2019: $ 62,959 $ 38,848 $ 8,000 $ 109,807 Impairment losses (StarStone International) — — (8,000) (8,000) Reclassification to assets held-for-sale (Atrium) — (38,848) — (38,848) Balance as of September 30, 2020: Goodwill 62,959 — 8,000 70,959 Accumulated impairment losses — — (8,000) (8,000) $ 62,959 $ — $ — $ 62,959 On August 13, 2020, we announced the Atrium Exchange Transaction, which resulted in the assets and liabilities of the Atrium segment being classified as held-for-sale as of September 30, 2020. On June 10, 2020, we announced the StarStone International Run-Off. During the three and nine months ended September 30, 2020, we recognized impairment losses of $nil and $8.0 million respectively, related to the goodwill allocated to StarStone International. Intangible Assets The gross carrying value, accumulated amortization and net carrying value of intangible assets by segment and by type as of September 30, 2020 and December 31, 2019 was as follows: September 30, 2020 December 31, 2019 Gross Accumulated amortization Net Gross Accumulated amortization Net Atrium segment: Intangible assets with a definite life: Distribution channel $ — $ — $ — $ 20,000 $ (8,111) $ 11,889 Brand — — — 7,000 (4,259) 2,741 Intangible assets with an indefinite life: Lloyd’s syndicate capacity — — — 33,031 — 33,031 Management contract — — — 30,100 — 30,100 Total Atrium segment intangible assets $ — $ — $ — $ 90,131 $ (12,370) $ 77,761 StarStone segment: Intangible assets with an indefinite life: Lloyd’s syndicate capacity 4,000 (4,000) — 4,000 — 4,000 Total intangible assets $ 4,000 $ (4,000) $ — $ 94,131 $ (12,370) $ 81,761 Atrium As described above, the assets and liabilities related to the Atrium segment have been classified as held-for-sale as of September 30, 2020. The following table presents the amortization recorded on the intangible assets prior to the reclassification to held-for-sale: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Intangible asset amortization $ 508 $ 546 $ 1,524 $ 1,676 StarStone

Debt Obligations and Credit Fac

Debt Obligations and Credit Facilities	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
DEBT OBLIGATIONS AND CREDIT FACILITIES	14. DEBT OBLIGATIONS AND CREDIT FACILITIES We utilize debt financing and credit facilities primarily for funding acquisitions and significant new business, investment activities and, from time to time, for general corporate purposes. Our debt obligations were as follows: Facility Origination Date Term September 30, 2020 December 31, 2019 4.50% Senior Notes due 2022 March 10, 2017 5 years $ 349,155 $ 348,616 4.95% Senior Notes due 2029 May 28, 2019 10 years 493,940 493,600 Total Senior Notes 843,095 842,216 5.75% Junior Subordinated Notes due 2040 August 26, 2020 20 years 344,813 — EGL Revolving Credit Facility August 16, 2018 5 years 260,000 — 2018 EGL Term Loan Facility December 27, 2018 3 years — 348,991 Total debt obligations $ 1,447,908 $ 1,191,207 During the nine months ended September 30, 2020, the EGL Revolving Credit Facility was utilized for funding (i) significant new business as described in Note 3 - "Significant New Business," (ii) investment opportunities and (iii) to provide additional liquidity in the first half of the year during the financial disruption associated with the COVID-19 pandemic. In addition, we issued the Junior Subordinated Notes and used the proceeds to repay the 2018 EGL Term Loan Facility. The table below provides a summary of the total interest expense: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Interest expense on debt obligations $ 14,652 $ 14,623 $ 41,522 $ 38,157 Amortization of debt issuance costs 351 311 914 539 Funds withheld balances and other — 16 — 326 Total interest expense $ 15,003 $ 14,950 $ 42,436 $ 39,022 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 4.50% interest semi-annually and mature on March 10, 2022. We incurred costs of $2.9 million in issuing the 2022 Senior Notes. The unamortized costs as of September 30, 2020 and December 31, 2019 were $0.8 million and $1.4 million, respectively. Refer to Note 15 - "Debt Obligations and Credit Facilities" in our 10-K for the year ended December 31, 2019 for further information regarding the 2022 Senior Notes. 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. We incurred costs of $6.8 million in issuing the 2029 Senior Notes. The unamortized costs as of September 30, 2020 and December 31, 2019 were $6.1 million and $6.4 million, respectively. Refer to Note 15 - "Debt Obligations and Credit Facilities" in our 10-K for the year ended December 31, 2019 for further information regarding the 2029 Senior Notes. Junior Subordinated Notes 5.75% Junior Subordinated Notes due 2040 On August 26, 2020, our wholly-owned subsidiary, Enstar Finance LLC ("Enstar Finance") issued the Junior Subordinated Notes for an aggregate principal amount of $350.0 million. The Junior Subordinated Notes pay interest (i) from the date of original issue to August 30, 2025 at the fixed rate of 5.75% per annum and (ii) from September 1, 2025, during each five-year period thereafter, at a rate per annum equal to the five-year treasury rate as of two business days prior to the beginning of such five-year period plus 5.468%, as reset at the beginning of each such five-year period. Absent certain conditions, interest on the Junior Subordinated Notes is payable semi-annually, commencing on March 1, 2021, and the Junior Subordinated Notes are scheduled to mature on September 1, 2040. The Junior Subordinated Notes are rated BB+ and are unsecured junior subordinated obligations of Enstar Finance. The Junior Subordinated Notes are fully and unconditionally guaranteed by us on an unsecured and junior subordinated basis. These debt securities of Enstar Finance are effectively subordinate to the obligations of our other subsidiaries. We incurred costs of $5.2 million in issuing the Junior Subordinated 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 Junior Subordinated Notes and are included in interest expense in our consolidated statements of earnings. The unamortized costs as of September 30, 2020 were $5.2 million. The net proceeds of $344.8 million, plus cash on hand, were used to repay $350.0 million of borrowings under our 2018 EGL Term Loan Facility, discussed further below. EGL Revolving Credit Facility As of September 30, 2020, we were permitted to borrow up to an aggregate of $600.0 million under the revolving credit facility. As of September 30, 2020, there was $340.0 million of available unutilized capacity under the facility. Subsequent to September 30, 2020, we have neither borrowed nor repaid any additional amounts under the facility, as such the unutilized capacity remains at $340.0 million. 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 bear interest at a rate based on the Company's long term senior unsecured debt ratings. 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. 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"). During 2019, we repaid principal of $150.0 million, and during the three months ended September 30, 2020, we repaid the remaining $350.0 million of principal on the facility. As of September 30, 2020, there was no amount outstanding on the 2018 EGL Term Loan Facility. We incurred costs of $1.5 million associated with closing the 2018 EGL Term Loan Facility. These costs were 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 September 30, 2020 and December 31, 2019 were $nil and $1.0 million, respectively. Letters of Credit We utilize unsecured and secured letters of credit to support certain of our insurance and reinsurance performance obligations. Funds at Lloyd's We had an unsecured letter of credit agreement for Funds at Lloyd's ("FAL Facility") as of September 30, 2020, 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 5, 2020, we amended and restated the FAL Facility to reduce its capacity to $275.0 million (with provision to increase the facility by an additional $75.0 million) and extend its term by two years. The FAL Facility is available to satisfy our Funds at Lloyd's requirements and expires in 2025. As of September 30, 2020 and December 31, 2019, our combined Funds at Lloyd's were comprised of cash and investments of $547.0 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. Pursuant to the facility agreement, we have the option to increase commitments under the facility by an additional $60.0 million. As of September 30, 2020 and December 31, 2019, we had issued an aggregate amount of letters of credit under this facility of $120.0 million and $115.3 million, respectively. $800.0 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 June 3, 2020. On August 4, 2020, we exercised our option to increase the commitments available under the facility by an aggregate amount of $40.0 million, bringing the total size of the facility to $800.0 million. The facility is used to collateralize certain reinsurance obligations, including $456.8 million relating to the reinsurance transaction with Maiden Reinsurance Ltd. As of September 30, 2020 and December 31, 2019, we had issued an aggregate amount of letters of credit under this facility of $619.8 million and $608.0 million, respectively. $65.0 million Letter of Credit Facility On August 4, 2020, we entered into a $65.0 million secured letter of credit facility agreement pursuant to which we issued a letter of credit to collateralize a portion of our reinsurance performance obligations relating to our novation transaction with Hannover Re, which we completed on August 6, 2020, as discussed in Note 3 - "Significant New Business". As of September 30, 2020, we had issued an aggregate amount of letters of credit under this facility of $61.0 million. 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 letter of credit facilities.

Noncontrolling Interests

Noncontrolling Interests	9 Months Ended
	Sep. 30, 2020
Noncontrolling Interest [Abstract]
NONCONTROLLING INTERESTS	15. NONCONTROLLING INTERESTSWe 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 September 30, 2020 and December 31, 2019 comprised the ownership interests held by the Trident V Funds ("Trident") (39.3%) and funds advised by 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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance at beginning of period $ 366,533 $ 435,696 $ 438,791 $ 458,543 Dividends paid — — — (11,556) Net earnings (losses) attributable to RNCI 20,997 (190) (31,102) (5,651) Accumulated other comprehensive earnings attributable to RNCI 1,220 (97) 7,593 58 Foreign currency translation adjustments (588) — (753) — Change in redemption value of RNCI (11,431) (622) (38,059) (6,607) Cumulative effect of change in accounting principle attributable to RNCI (1) — — 261 — Balance at end of period $ 376,731 $ 434,787 $ 376,731 $ 434,787 (1) The Company adopted ASU 2016-13 We carried the RNCI at its estimated redemption value, which is fair value, as of September 30, 2020 and December 31, 2019. The increase in the three months ended September 30, 2020 was attributable to $21.0 million of net earnings primarily related to StarStone due to higher underwriting income in the period; partially offset by, an $11.4 million reduction in redemption value. The redemption value decreased as a result of the agreement to sell Northshore. The decrease in the nine months ended September 30, 2020 was attributable to $31.1 million of net losses related to StarStone resulting from exit costs associated with the decision to place StarStone International into run-off; and $38.1 million due to change in redemption value. The redemption value decreased as a result of the StarStone International Run-Off decision and the agreement to sell both StarStone U.S and Northshore. Refer to Noncontrolling Interest As of September 30, 2020 and December 31, 2019, we had $14.5 million and $14.2 million, respectively, of NCI related to external interests in three of our 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

Share Capital	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
SHARE CAPITAL	16. 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 November 6, 2020: Dividend per: Preferred Share Series Date Declared Record Date Date Paid or Payable Preferred Share Depositary Share Total dividends paid in the nine months ended September 30, 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 7,000 Series E May 5, 2020 May 15, 2020 June 1, 2020 $ 437.50 $ 0.43750 1,925 Series D August 5, 2020 August 15, 2020 September 1, 2020 $ 437.50 $ 0.43750 7,000 Series E August 5, 2020 August 15, 2020 September 1, 2020 $ 437.50 $ 0.43750 1,925 Series D November 5, 2020 November 15, 2020 December 1, 2020 $ 437.50 $ 0.43750 — Series E November 5, 2020 November 15, 2020 December 1, 2020 $ 437.50 $ 0.43750 — $ 26,775 Share Repurchases On March 9, 2020, our Board of Directors adopted a stock trading plan for the purpose of repurchasing a limited number of our Company’s ordinary shares, not to exceed $150.0 million in aggregate (the "Repurchase Program"). On March 23, 2020, we suspended our Repurchase Program due to uncertainty in the global financial markets resulting from the COVID-19 pandemic. The Repurchase Program resumed on September 21, 2020 and expires on March 1, 2021. From inception to September 30, 2020, we repurchased 174,464 ordinary shares at an average price of $145.53, for an aggregate price of $25.4 million under the Repurchase Program. As of September 30, 2020, the remaining capacity under the Repurchase Program was $124.6 million. Subsequent to September 30, 2020, we repurchased 3,816 ordinary shares for an aggregate price of $0.6 million under the Repurchase program. 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.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
EARNINGS PER SHARE	17. EARNINGS PER SHARE The following table sets forth the computation of basic and diluted net earnings per ordinary share: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Numerator: Earnings (losses) attributable to Enstar ordinary shareholders: Net earnings from continuing operations (1) $ 612,636 $ 113,074 $ 896,267 $ 701,234 Net earnings from discontinued operations (2) 2,377 4,669 478 7,102 Net earnings attributable to Enstar ordinary shareholders: $ 615,013 $ 117,743 $ 896,745 $ 708,336 Denominator: Weighted-average ordinary shares outstanding — basic (3) 21,578,106 21,488,216 21,564,447 21,476,586 Effect of dilutive securities: Share-based compensation plans (4) 143,581 169,162 180,437 204,288 Warrants 57,042 63,119 54,743 60,625 Weighted-average ordinary shares outstanding — diluted 21,778,729 21,720,497 21,799,627 21,741,499 Earnings (loss) per ordinary share attributable to Enstar: Basic: Net earnings from continuing operations $ 28.39 $ 5.26 $ 41.56 $ 32.65 Net earnings from discontinued operations 0.11 0.22 0.02 0.33 Net earnings per ordinary share $ 28.50 $ 5.48 $ 41.58 $ 32.98 Diluted: Net earnings from continuing operations $ 28.13 $ 5.21 $ 41.12 $ 32.25 Net earnings from discontinued operations 0.11 0.21 0.02 0.33 Net earnings per ordinary share $ 28.24 $ 5.42 $ 41.14 $ 32.58 (1) Net earnings (loss) from continuing operations attributable to Enstar ordinary shareholders equals net earnings (loss) from continuing operations, plus net loss (earnings) from continuing operations attributable to noncontrolling interest, less dividends on preferred shares. (2) Net earnings (loss) from discontinued operations attributable to Enstar ordinary shareholders equals net earnings (loss) from discontinued operations, net of income taxes, plus net loss (earnings) from discontinued operations attributable to noncontrolling interest; refer to Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations" for a breakdown by period. (3) 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. (4) 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 and nine months ended September 30, 2020 because they were anti-dilutive.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2020
Retirement Benefits [Abstract]
SHARE-BASED COMPENSATION	18. 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Share-based compensation plans: Restricted shares and restricted share units $ 2,251 $ 1,778 $ 6,180 $ 4,910 Performance share units 5,698 5,678 10,886 18,133 Cash-settled stock appreciation rights 3,705 102 230 (109) Joint share ownership plan expense 1,146 — 3,151 — Other share-based compensation plans: Northshore incentive plan 209 1,029 656 3,061 StarStone incentive plan — — (223) — Deferred compensation and ordinary share plan for non-employee directors 139 116 1,098 992 Employee share purchase plan 110 102 318 309 Total share-based compensation $ 13,258 $ 8,805 $ 22,296 $ 27,296

Income Taxation

Income Taxation	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
INCOME TAXATION	19. 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 September 30, 2020 and 2019 were 2.1% and 10.2%, respectively. The effective tax rates on income for the nine months ended September 30, 2020 and 2019 were 2.8% and 3.4%, 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 lia bilities 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 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 and nine months ended September 30, 2020, we 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 September 30, 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

Related Party Transactions	9 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	20. 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. Our interests in StarStone and Atrium are held through North Bay, which is a joint venture between us and the Trident V Funds that are advised by Stone Point. We currently own an indirect 59.0% interest in North Bay and the Trident V Funds and the Dowling Funds currently own 39.3% and 1.7%, respectively. North Bay owns 100% of SSHL, the holding company for the StarStone group, which includes StarStone U.S. and StarStone International. North Bay also owns approximately 92% of Northshore, the holding company that owns Atrium and Arden. North Bay also owns the preferred equity of three segregated cells of Fitzwilliam Insurance Limited (the “Fitzwilliam Cells”) that have provided reinsurance to StarStone and are considered part of StarStone International. On June 10, 2020, North Bay and one of its subsidiaries entered into an agreement to sell StarStone U.S. to Core Specialty in a recapitalization transaction described in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations". Pursuant to the terms of a Recapitalization Agreement entered into on August 13, 2020 among us, the Trident V Funds and the Dowling Funds (the "Recapitalization Agreement"), we agreed to exchange a portion of our indirect interest in Northshore for all of the Trident V Funds’ indirect interest in StarStone U.S. (the “Exchange Transaction”), which is described in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations". In addition to the terms described in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations", the Recapitalization Agreement also provides for a preferred return to us of any cash received upon the sale of StarStone U.S. to reimburse us for certain funding provided to one of the Fitzwilliam Cells. To the extent the cash received upon the sale of StarStone U.S. exceeds the amount needed to reimburse us for the funding provided to the Fitzwilliam Cell, the portion of such cash that would otherwise be allocated to the Trident V Funds will be paid to us instead, and we would receive fewer shares in Northshore in the Exchange Transaction. In connection with the closing of the Exchange Transaction, we will enter into amended and restated shareholders’ agreements with the Trident V Funds and the Dowling Funds with respect to our investment in SSHL and Northshore. With respect to SSHL, we will have the right to designate three of five members of the SSHL board of directors and the Trident V Funds will have the right to designate the other two members. The Trident V Funds will also have certain customary rights as a minority shareholder to approve certain material matters and transactions. Each shareholder of SSHL will provide us and the Trident V Funds with a right of first offer to acquire its shares in SSHL if such shareholder wishes to sell them. Each shareholder will also have certain rights to participate in sales of SSHL shares by the other shareholders, and we will have certain rights to cause the Trident V Funds and the Dowling Funds to sell their SSHL shares if we wish to sell control of SSHL or the StarStone International business. Also pursuant to the terms of the proposed shareholders’ agreement for SSHL, at any time after December 31, 2022, the Trident V Funds will have the right to cause us to purchase their shares in SSHL at their fair market value, and the Dowling Funds will have the right to participate in any such sale transaction initiated by the Trident V Funds. We will be entitled to pay the purchase price for such SSHL shares in cash or in unrestricted ordinary shares of Enstar that are then listed or admitted to trading on a national securities exchange. At any time after March 31, 2023, we will have the right to cause the Trident V Funds and the Dowling Funds to sell their shares in SSHL to us at their fair market value. We would be obligated to pay the purchase price for such SSHL shares in cash. Pursuant to the terms of the proposed shareholders’ agreement for Northshore, for so long as we own 50% or more of the Northshore shares we acquire upon the closing of the Exchange Transaction, we will have the right to designate one member to the board of directors of Northshore and each of its material subsidiaries. Our shares in Northshore will be subject to an 18-month restriction on transfer following the closing of the Exchange Transaction, after which the Trident V Funds will have a right of first offer to acquire our shares in Northshore if we wish to sell them. We will have certain rights to participate in sales of Northshore shares by the Trident V Funds, and the Trident V Funds will have certain rights to cause us to sell our Northshore shares if the Trident V Funds wish to sell control of Northshore or the Atrium business. Pursuant to the terms of the existing shareholders’ agreements related to StarStone and Atrium, Mr. Carey serves as a representative of the Trident V Funds on the boards of the holding companies, including 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 previously 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: September 30, 2020 December 31, 2019 Redeemable Noncontrolling Interest $ 361,026 $ 420,499 As of September 30, 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; • 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; and • In the second quarter of 2020, we invested $10.0 million in a 2 year senior secured unrated floating rate term loan facility with an extension option which was arranged and managed by Sound Point Capital. The facility's borrower, Amplify U.S. Inc., is a subsidiary of Evergreen (as defined below) and has used the proceeds to purchase AmTrust's preferred stock. The facility ranks senior to all other claims of the borrower, the purchased preferred stock and cash flows therefrom serve as collateral, and AmTrust has provided an unsecured guarantee for the facility. For further information on our relationships with Evergreen and AmTrust, refer to the AmTrust section below. 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: September 30, 2020 December 31, 2019 Short-term investments, AFS, at fair value $ — $ 1,431 Fixed maturities, trading, at fair value 219,435 269,131 Fixed maturities, AFS, at fair value 93,779 160,303 Equities, at fair value 94,353 121,794 Other investments, at fair value: Hedge funds 18,510 18,993 Fixed income funds 335,033 381,449 Private equity funds 32,050 34,858 CLO equities 33,358 32,560 CLO equity funds 140,458 87,509 Private Debt 27,079 16,312 Real estate fund 24,475 18,106 Total investments 1,018,530 1,142,446 Cash and cash equivalents 21,293 54,080 Other assets 6,327 10 Other liabilities 162 4,710 Net investment $ 1,045,988 $ 1,191,826 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net investment income $ 2,312 $ 2,257 $ 11,189 $ 5,009 Net realized and unrealized (losses) gains 35,925 (3,442) (36,862) 26,305 Total net (losses) earnings $ 38,237 $ (1,185) $ (25,673) $ 31,314 We have made direct investments in funds (the “Hillhouse Funds”) managed by Hillhouse Capital Management, Ltd. and Hillhouse Capital Advisors, Ltd. (together, “Hillhouse Capital”) and AnglePoint Asset Management Ltd. ("AnglePoint"). As of September 30, 2020, our carrying value of our direct investment the InRe Fund, L.P. (the "InRe Fund"), which is managed by AnglePoint, was $1.8 billion with the InRe Fund's assets being invested in approximately (1)% in net short fixed income securities, 22% in North American equities, 49% in international equities and 30% in financing, derivatives and other items. As of September 30, 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 (as applicable): September 30, 2020 December 31, 2019 Investments in funds managed by AnglePoint, held by Enhanzed Re $ 653,040 $ 327,799 Our ownership of equity method investments 47.4 % 47.4 % Our share of Investments in funds managed by AnglePoint held by Enhanzed Re (through our ownership of equity method investments) $ 309,541 $ 155,377 Investment in other funds managed by Hillhouse Capital and AnglePoint: InRe Fund $ 1,843,532 $ 918,633 Other funds 306,214 232,968 $ 2,149,746 $ 1,151,601 The increase in the investment in the Hillhouse Funds was primarily due to additional subscriptions of $300.0 million and unrealized gains for the nine months ended September 30, 2020. We incurred management and performance fees of approximately $263.3 million, included within the Hillhouse Funds' reported NAV, for the nine months ended September 30, 2020 in relation to the investment in funds managed by Hillhouse Capital and AnglePoint as described above. Monument Insurance Group Limited ("Monument Re") was established in October 2016 and Enstar has invested a total of $59.6 million in the common and preferred shares of Monument Re as at September 30, 2020 (December 31, 2019: $26.6 million). We own 20% of the common shares of Monument Re, as well as different classes of preferred shares which have fixed dividend yields, and which collectively represented a total economic interest of 23.0% as at September 30, 2020 (December 31, 2019: 23.5%). In connection with our investment in Monument Re, we entered into a Shareholders Agreement with the other shareholders and have accounted for our equity interest in Monument Re as an equity method investment since we have significant influence over its operating and financial policies. 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 Re. In this transaction, we transferred policy benefits for life and annuity contracts with a carrying value of €88.8 million (or $99.1 million) and total assets with a fair value of €91.1 million (or $101.6 million) to a subsidiary of Monument Re. Our investment in the common and preferred shares of Monument Re, which is included in equity method investments on our consolidated balance sheet, was as follows: September 30, 2020 December 31, 2019 Investment in Monument Re $ 161,994 $ 60,598 During the three and nine months ended September 30, 2020 we received director fees from Monument Re of less than $0.1 million and $0.1 million, respectively, in connection with one of our representatives serving on Monument Re's board of directors. Clear Spring (formerly SeaBright) Effective January 1, 2017, we sold SeaBright Insurance Company (“SeaBright Insurance”) to Clear Spring PC Acquisition Corp., a subsidiary of Delaware Life Insurance Company ("Delaware Life"). Following the sale, SeaBright Insurance was capitalized with $56.0 million of equity, with Enstar retaining a 20% indirect equity interest in SeaBright Insurance. Subsequently, SeaBright Insurance was renamed Clear Spring Property and Casualty Company ("Clear Spring"). We have accounted for our equity interest in Clear Spring as an equity method investment as we have significant influence over its operating and financial policies. Our investment in the common shares of Clear Spring which is included in equity method investments on our consolidated balance sheet, was as follows: September 30, 2020 December 31, 2019 Investment in Clear Spring $ 10,944 $ 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: September 30, 2020 December 31, 2019 Balances under StarStone ceding quota share included, in assets or liabilities held-for-sale: Reinsurance balances recoverable $ 20,998 $ 22,812 Prepaid insurance premiums — 51 Ceded payable 3,551 3,616 Ceded acquisition costs — 21 Balances under assuming quota share: Losses and LAE 3,995 6,135 Unearned reinsurance premiums — 13 Funds held 7,468 8,611 Our consolidated statement of earnings included the following amounts between us and Clear Spring: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Transactions under StarStone ceding quota share, included in net earnings (loss) from discontinued operations: Ceded premium earned $ 60 $ (3,548) $ 61 $ (13,304) Ceded incurred losses and LAE (525) 1,063 (1,814) 8,051 Ceded acquisition costs (17) 243 (44) 305 Transactions under assuming quota share: Premium earned (15) 887 (15) 3,326 Net incurred losses and LAE 132 (576) 1,014 (2,013) Acquisition costs 4 (88) 11 (79) Total net earnings (loss) $ (361) $ (2,019) $ (787) $ (3,714) 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. Our indirect investment in the shares of AmTrust, carried in equities on our consolidated balance sheet was as follows: September 30, 2020 December 31, 2019 Investment in AmTrust $ 245,361 $ 240,115 The following table presents the amounts included in net earnings related to our related party transactions with AmTrust: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net investment income $ — $ 1,900 $ 4,367 $ 5,550 Net realized and unrealized gains 45 — 3,854 — Total net earnings $ 45 $ 1,900 $ 8,221 $ 5,550 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 September 30, 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, which is included in equity method investments on our consolidated balance sheet, was as follows: September 30, 2020 December 31, 2019 Investment in Citco $ 51,946 $ 51,742 Enhanzed Re. Enstar owns 47.4% of the entity, Allianz owns 24.9% and an affiliate of Hillhouse Capital owns 27.7%. As of September 30, 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, which is included in equity method investments on our consolidated balance sheet, was as follows: September 30, 2020 December 31, 2019 Investment in Enhanzed Re $ 271,678 $ 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. Effective October 1, 2020, we have ceded 10% of the AXA Group transaction, as described in Note 3 - "Significant New Business," 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: September 30, 2020 December 31, 2019 Balances under ceding quota share: Insurance balances payables $ 1,759 $ 1,443 Reinsurance balances recoverable 53,762 59,601 Funds held 47,808 50,089 Other assets 498 1,033 Our consolidated statement of earnings included the following amounts between us and Enhanzed Re: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Amounts under ceding quota share: Net incurred losses and LAE $ (1) $ — $ (14) $ — Acquisition costs (46) — (23) — Net investment income (819) — (819) — Net realized and unrealized gains (679) — (679) — Other income 3,113 — — — Fees and commission income 161 150 393 402 Total Net earnings 1,729 150 (1,142) 402 Change in realized gain (losses) on available-for-sale investments (2,239) — (2,239) —

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	21. 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 September 30, 2020, we had a significant funds held concentration of $948.3 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 September 30, 2020. Our credit exposure to the U.S. government was $1.2 billion as of September 30, 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 September 30, 2020, we had unfunded commitments of $792.2 million to other investments, $68.7 million to equity method investments and $15.0 million to fixed maturity investments. Guarantees As of September 30, 2020 and December 31, 2019, parental guarantees and capital instruments supporting subsidiaries' insurance obligations were $1.4 billion and $1.0 billion, respectively. We also guarantee the Junior Subordinated Notes and the FAL facility, which are described in Note 14 - "Debt Obligations and Credit Facilities." In connection with the sale of StarStone U.S., the net loss reserves of StarStone U.S. will be reinsured to an Enstar Non-life Run-off entity upon completion of the sale which is expected to occur in the fourth quarter of 2020. The obligations under the loss portfolio transfer reinsurance agreement will be guaranteed by Enstar. Refer to Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations" for further details. 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"). Pursuant to the Exchange Transaction described in Note 20 - "Related Party Transactions" we have agreed to exchange a portion of our indirect interest in Northshore for all of the Trident V Funds' indirect interest in StarStone U.S. Following the closing of the Exchange Transaction, we will maintain a call right over the portion of SSHL owned by the Trident V Funds and the Dowling Funds, and they will maintain put rights to transfer those interests to us. 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Lease cost: Operating lease cost $ 3,036 $ 4,010 $ 9,560 $ 10,696 Short-term lease cost (1) 63 — 182 — Total lease cost 3,099 4,010 9,742 10,696 Sub-lease income (2) (139) (183) (415) (451) Total net lease cost $ 2,960 $ 3,827 $ 9,327 $ 10,245 Other information: Operating cash paid for amounts included in the measurement of lease liabilities $ 2,856 $ 2,945 $ 10,184 $ 9,138 Non-cash activity: right-of-use assets relating to leases (179) 1,353 84 53,581 Weighted-average remaining lease term 6.1 years 6.4 years Weighted-average discount rate 6.4 % 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 September 30, 2020 December 31, 2019 Right-of-use assets (1) (2) Other assets $ 33,224 $ 46,747 Current lease liabilities (2) Other liabilities 7,955 11,403 Non-current lease liabilities (2) Other liabilities 28,126 34,785 (1) Following our decision to put the StarStone International operations into orderly run-off effective June 10, 2020, we recorded total impairment charges of $3.5 million on the right-of-use assets relating to certain StarStone International operating leases as of September 30, 2020. (2) The right-of-use assets and the total lease liability balances exclude balances of $1.5 million and $1.0 million respectively, related to Atrium which have been reclassified to held-for-sale balances on our consolidated balance sheet as of September 30, 2020. The table below provides a summary of the contractual maturities of our operating lease liabilities: September 30, 2020 2020 $ 2,938 2021 9,347 2022 7,829 2023 7,032 2024 5,328 2025 and beyond 12,579 Total lease payments (1) 45,053 Less: Imputed interest (8,972) Present value of lease liabilities $ 36,081

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
SEGMENT INFORMATION	22. 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 September 30, 2020 Non-life Atrium StarStone Other Total Gross premiums written $ 3,535 $ 49,083 $ 58,566 $ 293 $ 111,477 Net premiums written $ 3,424 $ 46,503 $ 43,338 $ 294 $ 93,559 Net premiums earned $ 17,476 $ 42,426 $ 96,116 $ 5,706 $ 161,724 Net incurred losses and LAE (34,258) (21,995) (48,390) (5,043) (109,686) Acquisition costs (2,730) (14,242) (20,608) (128) (37,708) Operating expenses (50,345) (3,008) (20,440) — (73,793) Underwriting income (loss) (69,857) 3,181 6,678 535 (59,463) Net investment income (loss) 66,918 1,778 6,298 (2,864) 72,130 Net realized and unrealized gains 486,671 1,533 11,801 — 500,005 Fees and commission income 3,637 7,150 — — 10,787 Other income 48,023 72 99 210 48,404 Corporate expenses (22,494) (6,084) (3,137) (10,320) (42,035) Interest income (expense) (16,705) — (510) 2,212 (15,003) Net foreign exchange gains (losses) (9,663) 2,275 (761) (7) (8,156) EARNINGS (LOSS) BEFORE INCOME TAXES 486,530 9,905 20,468 (10,234) 506,669 Income tax expense (9,271) (2,520) (733) (1,391) (13,915) Earnings from equity method investments 149,065 — — — 149,065 NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 626,324 7,385 19,735 (11,625) 641,819 NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES — — 4,031 — 4,031 NET EARNINGS (LOSS) 626,324 7,385 23,766 (11,625) 645,850 Net earnings attributable to noncontrolling interest (2,519) (2,996) (16,397) — (21,912) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR 623,805 4,389 7,369 (11,625) 623,938 Dividends on preferred shares — — — (8,925) (8,925) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 623,805 $ 4,389 $ 7,369 $ (20,550) $ 615,013 Underwriting ratios: Loss ratio 51.8 % 50.3 % Acquisition expense ratio 33.6 % 21.4 % Operating expense ratio 7.1 % 21.4 % Combined ratio 92.5 % 93.1 % Three Months Ended September 30, 2019 Non-life Atrium StarStone Other Total Gross premiums written $ 301 $ 48,746 $ 110,586 $ (2,498) $ 157,135 Net premiums written $ (3,808) $ 43,785 $ 76,020 $ (2,503) $ 113,494 Net premiums earned $ 16,837 $ 42,913 $ 111,749 $ 4,303 $ 175,802 Net incurred losses and LAE (30,583) (28,400) (100,628) (3,647) (163,258) Acquisition costs 4,634 (14,466) (23,301) (177) (33,310) Operating expenses (51,395) (3,742) (14,525) — (69,662) Underwriting income (loss) (60,507) (3,695) (26,705) 479 (90,428) Net investment income (loss) 73,752 1,736 8,161 (2,147) 81,502 Net realized and unrealized gains 138,174 582 6,034 270 145,060 Fees and commission income (expense) 4,196 2,391 (150) — 6,437 Other income (expense) (285) 35 72 1,000 822 Corporate expenses (11,983) (2,896) — (12,824) (27,703) Interest income (expense) (17,964) — — 3,014 (14,950) Net foreign exchange gains (losses) 13,056 (924) 1,509 24 13,665 EARNINGS (LOSS) BEFORE INCOME TAXES 138,439 (2,771) (11,079) (10,184) 114,405 Income tax benefit (expense) (13,382) (222) 139 — (13,465) Earnings from equity method investments 17,703 — — — 17,703 NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 142,760 (2,993) (10,940) (10,184) 118,643 NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES — — 7,916 — 7,916 NET EARNINGS (LOSS) 142,760 (2,993) (3,024) (10,184) 126,559 Net (earnings) loss attributable to noncontrolling interest (1,439) 1,228 320 — 109 NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR 141,321 (1,765) (2,704) (10,184) 126,668 Dividend on preferred shares — — — (8,925) (8,925) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 141,321 $ (1,765) $ (2,704) $ (19,109) $ 117,743 Underwriting ratios: Loss ratio 66.2 % 90.0 % Acquisition expense ratio 33.7 % 20.9 % Operating expense ratio 8.7 % 13.0 % Combined ratio 108.6 % 123.9 % Nine Months Ended September 30, 2020 Non-Life Atrium StarStone Other Total Gross premiums written $ 1,707 $ 155,551 $ 300,135 $ 3,237 $ 460,630 Net premiums written $ 2,397 $ 136,093 $ 227,066 $ 3,238 $ 368,794 Net premiums earned $ 44,023 $ 128,183 $ 276,566 $ 15,174 $ 463,946 Net incurred losses and LAE (63,698) (66,003) (197,259) (12,718) (339,678) Acquisition costs (13,226) (43,235) (76,026) (331) (132,818) Operating expenses (147,117) (8,757) (66,385) — (222,259) Underwriting income (loss) (180,018) 10,188 (63,104) 2,125 (230,809) Net investment income (loss) 223,425 4,382 21,625 (8,145) 241,287 Net realized and unrealized gains (losses) 838,483 3,392 (3,323) — 838,552 Fees and commission income 12,588 15,737 — — 28,325 Other income (expense) 68,087 105 216 (647) 67,761 Corporate expenses (48,014) (14,494) (39,153) (35,166) (136,827) Interest income (expense) (48,785) — (1,611) 7,960 (42,436) Net foreign exchange gains (losses) 385 1,115 (5,509) 2,634 (1,375) EARNINGS (LOSS) BEFORE INCOME TAXES 866,151 20,425 (90,859) (31,239) 764,478 Income tax expense (18,276) (3,303) (2,325) (1,391) (25,295) Earnings from equity method investments 152,725 — — — 152,725 NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 1,000,600 17,122 (93,184) (32,630) 891,908 NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES — — 810 — 810 NET EARNINGS (LOSS) 1,000,600 17,122 (92,374) (32,630) 892,718 Net (earnings) loss attributable to noncontrolling interest 504 (7,024) 37,322 — 30,802 NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR 1,001,104 10,098 (55,052) (32,630) 923,520 Dividends on preferred shares — — — (26,775) (26,775) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 1,001,104 $ 10,098 $ (55,052) $ (59,405) $ 896,745 Underwriting ratios: Loss ratio 51.5 % 71.3 % Acquisition expense ratio 33.7 % 27.5 % Operating expense ratio 6.9 % 24.0 % Combined ratio 92.1 % 122.8 % Nine Months Ended September 30, 2019 Non-Life Atrium StarStone Other Total Gross premiums written $ (24,785) $ 146,519 $ 363,352 $ (1,174) $ 483,912 Net premiums written $ (26,395) $ 127,246 $ 291,083 $ (1,197) $ 390,737 Net premiums earned $ 141,981 $ 119,865 $ 339,993 $ 16,872 $ 618,711 Net incurred losses and LAE (135,517) (58,662) (358,864) (13,068) (566,111) Acquisition costs (40,033) (41,023) (80,582) (554) (162,192) Operating expenses (139,595) (9,968) (53,217) — (202,780) Underwriting income (loss) (173,164) 10,212 (152,670) 3,250 (312,372) Net investment income (loss) 206,337 5,500 25,865 (6,278) 231,424 Net realized and unrealized gains 815,902 5,464 31,274 5,849 858,489 Fees and commission income (expense) 13,673 5,773 (515) — 18,931 Other income (expense) 15,136 106 445 (319) 15,368 Corporate expenses (47,287) (10,186) — (36,051) (93,524) Interest income (expense) (45,699) — (475) 7,152 (39,022) Net foreign exchange gains (losses) 20,426 (1) (326) (2) 20,097 EARNINGS (LOSS) BEFORE INCOME TAXES 805,324 16,868 (96,402) (26,399) 699,391 Income tax benefit (expense) (23,501) (1,930) 251 (85) (25,265) Earnings (loss) from equity method investments 44,406 — (218) — 44,188 NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 826,229 14,938 (96,369) (26,484) 718,314 NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES — — 12,041 — 12,041 NET EARNINGS (LOSS) 826,229 14,938 (84,328) (26,484) 730,355 Net (earnings) loss attributable to noncontrolling interest (6,351) (6,127) 17,448 — 4,970 NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR 819,878 8,811 (66,880) (26,484) 735,325 Dividends on preferred shares — — — (26,989) (26,989) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 819,878 $ 8,811 $ (66,880) $ (53,473) $ 708,336 Underwriting ratios: Loss ratio 48.9 % 105.6 % Acquisition expense ratio 34.2 % 23.7 % Operating expense ratio 8.4 % 15.6 % Combined ratio 91.5 % 144.9 % 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: September 30, 2020 December 31, 2019 Assets by Segment: Non-life Run-off (1) $ 17,961,439 $ 15,775,407 Atrium (2) 638,529 580,405 StarStone (3) 4,021,240 3,985,138 Other (850,620) (514,851) Total assets $ 21,770,588 $ 19,826,099 (1) The total assets within the Non-life Run-off segment include assets of $12.4 million related to Arden's operations that have been included within Northshore's held-for-sale assets in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations." (2) The total assets within the Atrium segment are all included within Northshore's held-for-sale assets in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations." (3) The total assets within the StarStone segment include assets of $1.5 billion related to StarStone U.S. which are disclosed as held-for-sale assets in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations."

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
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.
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 as described in further detail in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations." 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.
Short-term investments and fixed maturity investments	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	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 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 and Recently Issued Accounting Pronouncements Not Yet Adopted	New Accounting Standards Adopted in 2020 ASU 2020-04 – Reference Rate Reform In March 2020, the Financial Accounting Standards Board ("FASB") issued ASU 2020-04 – Reference Rate Reform – Facilitation of the Effects of Reference Rate Reform on Financial Reporting , which is codified in Accounting Standards Codification ("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 guidance, 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 this guidance must be applied prospectively for all eligible contract modifications. The ASU was effective upon issuance and can be applied through to December 31, 2022. We adopted the ASU upon its issuance and as we transition from LIBOR to alternative reference rates, we will 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. The adoption of this standard did not have any impact on our consolidated financial statements and disclosures. ASU 2020-03 – Codification Improvements to Financial Instruments In March 2020, the 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 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 • 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, we are yet to adopt the following accounting pronouncements that the FASB issued during and subsequent to the nine months ended September 30, 2020. ASU 2020-09 – Amendments to SEC Paragraphs Pursuant to SEC Release No. 33-10762 In October 2020, the FASB issued ASU 2020-09, which amends and supersedes various SEC paragraphs in ASC 270, ASC 460, ASC 470 and ASC 505 pursuant to the issuance of the SEC's Release No. 33-10762. Through Release No. 33-10762, the SEC made amendments to the financial disclosure requirements in Regulation S-X for guarantors and issuers of guaranteed securities registered or being registered, and issuers’ affiliates whose securities collateralize securities registered or being registered, to improve those requirements for both investors and registrants. The changes made by the SEC are intended to provide investors with material information given the specific facts and circumstances, make the disclosures easier to understand, and reduce the costs and burdens to registrants. In addition, by reducing the costs and burdens of compliance, issuers may be encouraged to offer guaranteed or collateralized securities on a registered basis, thereby affording investors protection they may not be provided in offerings conducted on an unregistered basis. Finally, by making it less burdensome and less costly for issuers to include guarantees or pledges of affiliate securities as collateral when they structure debt offerings, the revisions may increase the number of registered offerings that include these credit enhancements, which could result in a lower cost of capital and an increased level of investor protection. The amended rules in Release No. 33-10762 are effective on January 4, 2021 although early compliance is permitted, hence we elected early compliance with the new rules. Because the amendments made by the FASB in this ASU are to ensure alignment of the relevant SEC paragraphs in ASC 270, ASC 460, ASC 470 and ASC 505 with the amended rules in Release No. 33-10762, the amendments made by the FASB to these SEC paragraphs will not have a material impact on our disclosures, since we already elected early compliance with the amended rules in Release No. 33-10762. ASU 2020-08 – Codification Improvements to Subtopic 310-20 - Receivables - Nonrefundable Fees and Other Costs In October 2020, the FASB issued ASU 2020-08 to clarify that an entity should re-evaluate whether a callable debt security is within the scope of ASC 310-20-35-33 during each reporting period. All entities are required to apply the amendments in this ASU on a prospective basis as of the beginning of the period of adoption for existing or newly purchased callable debt securities. The amendments in this ASU are effective for interim and annual reporting periods beginning after December 15, 2020, and early adoption is not permitted. We do not expect the adoption of this guidance to have a material impact on our consolidated financial statements and the related disclosures. ASU 2020-06 – Accounting for Convertible Instruments and Contracts in an Entity's Own Equity In August 2020, the FASB issued ASU 2020-06, which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts in an entity's own equity. For convertible instruments, the ASU eliminates two of the three accounting models in ASC 470-20 that require separate accounting for embedded conversion features. The ASU also simplifies an issuer's application of the derivatives scope exception in ASC 815-40 for contracts in its own equity and removes some of the conditions that preclude a freestanding contract from being classified in equity, thereby allowing more of such contracts to qualify for equity classification. The amendments in this ASU are effective for interim and annual reporting periods beginning after December 15, 2021 and, although early adoption is permitted, the amendments may not be adopted earlier than during interim and annual reporting periods beginning after December 15, 2020. We do not expect the adoption of this guidance to have a material impact on our consolidated financial statements and the related disclosures.

Divestitures, Held-For-Sale B_2

Divestitures, Held-For-Sale Businesses and Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2020
Discontinued Operations and Disposal Groups [Abstract]
Financial Information of Held-For-Sale Business	We have classified the assets and liabilities of Northshore as held-for-sale as of September 30, 2020. The impending disposal of Enstar's majority equity interest in Northshore does not represent a strategic shift that will have a major effect on our operations and financial results, and therefore the disposal is not reported as a discontinued operation during the current or prior periods. The following table summarizes the components of Northshore's assets and liabilities held-for-sale on our consolidated balance sheets as of September 30, 2020: September 30, 2020 ASSETS Short-term investments, available-for-sale, at fair value $ 1,852 Fixed maturities, trading, at fair value 154,325 Fixed maturities, available-for-sale, at fair value 9,252 Equities, at fair value 18,120 Other investments, at fair value 87,795 Total investments 271,344 Cash and cash equivalents 61,221 Restricted cash and cash equivalents 10,152 Premiums receivable 59,484 Deferred tax assets 97 Reinsurance balances recoverable on paid and unpaid losses 30,673 Funds held by reinsured companies 30,092 Deferred acquisition costs 24,522 Goodwill and intangible assets 115,085 Other assets 48,308 TOTAL ASSETS HELD-FOR-SALE $ 650,978 LIABILITIES Losses and loss adjustment expenses $ 248,532 Unearned premiums 91,608 Insurance and reinsurance balances payable 10,916 Deferred tax liabilities 14,010 Other liabilities 66,020 TOTAL LIABILITIES HELD-FOR-SALE $ 431,086 NET ASSETS HELD-FOR-SALE $ 219,892 September 30, 2020 December 31, 2019 (1) ASSETS Fixed maturities, trading, at fair value $ 140,124 $ 202,994 Fixed maturities, available-for-sale, at fair value 525,842 375,337 Equities, at fair value 5,494 3,000 Other investments, at fair value 6,864 6,389 Total investments 678,324 587,720 Cash and cash equivalents 54,303 78,613 Restricted cash and cash equivalents 9,390 5,815 Premiums receivable 105,339 99,367 Deferred tax assets 14,890 15,191 Reinsurance balances recoverable on paid and unpaid losses 477,739 530,604 Funds held by reinsured companies 29,678 35,861 Deferred acquisition costs 32,071 36,992 Goodwill and intangible assets 24,900 24,900 Other assets 78,876 59,707 TOTAL ASSETS HELD-FOR-SALE $ 1,505,510 $ 1,474,770 LIABILITIES Losses and loss adjustment expenses $ 830,456 $ 836,761 Unearned premiums 217,375 218,166 Insurance and reinsurance balances payable 49,822 22,453 Other liabilities 124,604 131,151 TOTAL LIABILITIES HELD-FOR-SALE $ 1,222,257 $ 1,208,531 NET ASSETS HELD-FOR-SALE $ 283,253 $ 266,239 (1) In accordance with U.S. GAAP, the assets and liabilities of StarStone U.S. as of December 31, 2019 have been reclassified to held-for-sale as a result of the business qualifying as a discontinued operation. Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 INCOME Net premiums earned $ 75,414 $ 94,523 $ 241,363 $ 263,464 Fees and commission income — 150 — 515 Net investment income 3,649 3,970 11,063 11,831 Net realized and unrealized gains 1,910 3,125 2,757 20,198 Other income 55 4 80 10 81,028 101,772 255,263 296,018 EXPENSES Net incurred losses and loss adjustment expenses 44,939 59,159 157,648 185,048 Acquisition costs 14,776 16,972 47,570 48,733 General and administrative expenses 16,675 16,558 47,404 47,213 Interest expense 535 — 1,715 1,355 Net foreign exchange (gains) losses (3) 34 (5) 29 76,922 92,723 254,332 282,378 EARNINGS (LOSS) BEFORE INCOME TAXES 4,106 9,049 931 13,640 Income tax benefit (expense) (75) (1,133) (121) (1,599) NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES $ 4,031 $ 7,916 $ 810 $ 12,041 Net loss (earnings) from discontinued operations attributable to noncontrolling interest (1,654) (3,247) (332) (4,939) NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 2,377 $ 4,669 $ 478 $ 7,102 The following table presents the cash flows of StarStone U.S. for the nine months ended September 30, 2020 and 2019: Nine Months Ended September 30, 2020 2019 Operating activities $ 114,024 $ 210,666 Investing activities (134,759) (5,332) Change in cash and restricted cash of business held-for-sale $ (20,735) $ 205,334 The table below presents a summary of the total income and expenses recognized in continuing operations for the three and nine months ended September 30, 2020 and 2019, relating to intercompany transactions, primarily intragroup reinsurances, between StarStone U.S. and our other subsidiaries: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Total income $ 1,709 $ 3,373 $ 9,072 $ 8,082 Total expenses (income) (1,783) (4,582) (16,682) 41,884 Net earnings (loss) $ 3,492 $ 7,955 $ 25,754 $ (33,802) The following table provides a reconciliation of the assets and liabilities of Northshore and StarStone U.S. held-for-sale on our consolidated balance sheet: September 30, 2020 Assets held-for-sale: Northshore (Atrium and Arden Re) $ 650,978 StarStone U.S. 1,505,510 Total $ 2,156,488 Liabilities held-for-sale: Northshore (Atrium and Arden Re) $ 431,086 StarStone U.S. 1,222,257 Total $ 1,653,343

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	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: September 30, 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 $ 3,399 $ 252,449 $ 148,378 $ 298,140 $ 87,264 $ 789,630 U.K. government — — 71,803 42,974 — 114,777 Other government 2,872 — 327,406 136,130 24,039 490,447 Corporate 862 25,726 3,474,857 1,653,722 524,742 5,679,909 Municipal — — 79,296 30,806 51,737 161,839 Residential mortgage-backed — — 157,773 293,811 77,655 529,239 Commercial mortgage-backed — — 382,735 228,207 232,177 843,119 Asset-backed — — 357,394 199,682 56,587 613,663 Total fixed maturity and short-term investments $ 7,133 $ 278,175 $ 4,999,642 $ 2,883,472 $ 1,054,201 $ 9,222,623 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 $ 208,296 $ 269,661 $ 106,537 $ 696,077 U.K. government 24,411 1,069 122,012 14,280 — 161,772 Other government 21,958 387 575,017 84,760 20,734 702,856 Corporate 5,121 13,915 3,959,288 866,557 603,389 5,448,270 Municipal — 1,381 87,451 2,399 49,456 140,687 Residential mortgage-backed — — 215,521 99,188 86,205 400,914 Commercial mortgage-backed — — 534,357 49,046 230,343 813,746 Asset-backed — — 441,393 152,161 76,681 670,235 Total fixed maturity and short-term investments $ 51,490 $ 128,335 $ 6,143,335 $ 1,538,052 $ 1,173,345 $ 9,034,557
Summary of Amortized Cost and Estimated Fair Value of Fixed Maturities by Contractual Maturity	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 September 30, 2020 Amortized Fair Value % of Total One year or less $ 556,125 $ 559,086 6.1 % More than one year through two years 589,231 598,559 6.5 % More than two years through five years 2,080,715 2,163,967 23.5 % More than five years through ten years 2,010,769 2,149,170 23.3 % More than ten years 1,595,695 1,765,820 19.1 % Residential mortgage-backed 521,383 529,239 5.7 % Commercial mortgage-backed 821,995 843,119 9.1 % Asset-backed 631,133 613,663 6.7 % $ 8,807,046 $ 9,222,623 100.0 %
Credit Ratings Company's Fixed Maturity and Short-Term Investments Available-for-Sale	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 September 30, 2020: Amortized Fair Value % of Total AAA AA Rated A Rated BBB Non- Not Rated U.S. government and agency $ 769,544 $ 789,630 8.6 % $ 789,630 $ — $ — $ — $ — $ — U.K. government 111,169 114,777 1.2 % — 102,624 8,739 — — 3,414 Other government 466,575 490,447 5.3 % 242,097 150,005 43,003 45,884 9,458 — Corporate 5,339,160 5,679,909 61.6 % 206,345 583,595 2,704,861 1,912,857 267,765 4,486 Municipal 146,087 161,839 1.8 % 7,137 83,519 51,538 19,645 — — Residential mortgage-backed 521,383 529,239 5.7 % 517,915 — 2,154 1,612 5,251 2,307 Commercial mortgage-backed 821,995 843,119 9.1 % 576,643 111,720 77,391 64,898 5,308 7,159 Asset-backed 631,133 613,663 6.7 % 249,237 99,942 145,494 96,960 21,780 250 Total $ 8,807,046 $ 9,222,623 100.0 % $ 2,589,004 $ 1,131,405 $ 3,033,180 $ 2,141,856 $ 309,562 $ 17,616 % of total fair value 28.1 % 12.3 % 32.9 % 23.2 % 3.3 % 0.2 %
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 September 30, 2020 were as follows: Gross Unrealized Losses As of September 30, 2020 Amortized Cost Gross Unrealized Gains Non-Credit Related Losses Allowance for Credit Losses (1) Fair Value U.S. government and agency $ 546,799 $ 4,071 $ (281) $ — $ 550,589 U.K. government 42,025 995 (46) — 42,974 Other government 131,861 4,279 (10) — 136,130 Corporate 1,646,014 40,601 (6,383) (784) 1,679,448 Municipal 29,810 1,012 (16) — 30,806 Residential mortgage-backed 292,153 2,211 (551) (2) 293,811 Commercial mortgage-backed 226,292 4,347 (2,351) (81) 228,207 Asset-backed 200,626 642 (1,541) (45) 199,682 $ 3,115,580 $ 58,158 $ (11,179) $ (912) $ 3,161,647 (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 Fair Value U.S. government and agency $ 381,488 $ 78 $ (322) $ 381,244 U.K. government 15,067 282 — 15,349 Other government 84,116 1,119 (88) 85,147 Corporate 880,667 3,739 (3,934) 880,472 Municipal 3,770 12 (2) 3,780 Residential mortgage-backed 99,646 221 (679) 99,188 Commercial mortgage-backed 49,219 30 (203) 49,046 Asset-backed 152,153 127 (119) 152,161 $ 1,666,126 $ 5,608 $ (5,347) $ 1,666,387
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	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 September 30, 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 September 30, 2020 Fair Gross Unrealized Fair Gross Unrealized Fair Gross Unrealized U.S. government and agency $ — $ — $ 170,590 $ (281) $ 170,590 $ (281) U.K. government — — 2,911 (46) 2,911 (46) Other government — — 7,392 (10) 7,392 (10) Corporate — — 498,974 (5,585) 498,974 (5,585) Municipal — — 3,551 (16) 3,551 (16) Residential mortgage-backed — — 136,602 (383) 136,602 (383) Commercial mortgage-backed — — 69,226 (1,652) 69,226 (1,652) Asset-backed — — 135,857 (1,386) 135,857 (1,386) Total fixed maturity and short-term investments $ — $ — $ 1,025,103 $ (9,359) $ 1,025,103 $ (9,359) 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 Gross Unrealized Fair Gross Unrealized Fair Gross Unrealized U.S. government and agency $ — $ — $ 193,574 $ (322) $ 193,574 $ (322) Other government 1,080 (23) 37,796 (65) 38,876 (88) Corporate 2,754 (306) 338,965 (3,628) 341,719 (3,934) Municipal 128 — 761 (2) 889 (2) Residential mortgage-backed — — 52,005 (679) 52,005 (679) Commercial mortgage-backed — — 35,777 (203) 35,777 (203) Asset-backed — — 101,591 (119) 101,591 (119) Total fixed maturity and short-term investments $ 3,962 $ (329) $ 760,469 $ (5,018) $ 764,431 $ (5,347)
Summary of Allowance for Credit Losses	The following tables provide a reconciliation of the beginning and ending allowance for credit losses on our AFS debt securities: Three Months Ended September 30, 2020 Other Corporate Residential mortgage-backed Commercial Asset-backed Total Allowance for credit losses, beginning of period $ — $ (3,090) $ — $ (494) $ (89) $ (3,673) Cumulative effect of change in accounting principle — — — — — — Allowances for credit losses on securities for which credit losses were not previously recorded — (39) (2) (78) (45) (164) Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets — — — — — — Reductions for securities sold during the period — 341 — — — 341 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 — — — — — — (Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period — 2,004 — 491 89 2,584 Allowance for credit losses, end of period $ — $ (784) $ (2) $ (81) $ (45) $ (912) Nine Months Ended September 30, 2020 Other Corporate Residential mortgage-backed Commercial Asset-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 — (10,359) (2) (572) (134) (11,067) Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets — — — — — — Reductions for securities sold during the period 22 2,108 — — — 2,130 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 — — — — — — (Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period — 10,454 — 541 89 11,084 Allowance for credit losses, end of period $ — $ (784) $ (2) $ (81) $ (45) $ (912)
Schedule of Equity Securities	The following table summarizes our equity investments classified as trading: September 30, 2020 December 31, 2019 Publicly traded equity investments in common and preferred stocks $ 303,932 $ 327,875 Exchange-traded funds 78,182 133,047 Privately held equity investments in common and preferred stocks 271,045 265,799 $ 653,159 $ 726,721
Other Investments	The following table summarizes our other investments carried at fair value: September 30, 2020 December 31, 2019 Hedge funds $ 2,087,091 $ 1,121,904 Fixed income funds 684,031 481,039 Equity funds 290,129 410,149 Private equity funds 320,455 323,496 CLO equities 84,532 87,555 CLO equity funds 140,458 87,509 Private credit funds 90,476 — Other 7,698 6,379 $ 3,704,870 $ 2,518,031 Less than 1 Year 1-2 years 2-3 years Not Eligible/ Restricted Total Redemption Frequency Hedge funds $ 793,268 $ 1,131,505 $ 102,600 $ 59,718 $ 2,087,091 Monthly to Bi-annually Fixed income funds 671,333 — — 12,698 684,031 Daily to Quarterly Equity funds 290,129 — — — 290,129 Daily to Quarterly Private equity funds — — — 320,455 320,455 N/A CLO equities 84,532 — — — 84,532 N/A CLO equity funds 101,597 29,113 9,748 — 140,458 Quarterly to Bi-annually Private credit funds — 10,000 80,476 90,476 N/A Other 7,698 7,698 N/A $ 1,940,859 $ 1,170,618 $ 112,348 $ 481,045 $ 3,704,870
Equity Method Investments	The following table summarizes our equity method investments: September 30, 2020 December 31, 2019 Investment Ownership % Carrying Value Investment Ownership % Carrying Value Enhanzed Re $ 154,050 47.4 % $ 271,678 $ 154,050 47.4 % $ 182,856 Citco 50,000 31.9 % 51,946 50,000 31.9 % 51,742 Monument Re (1) 59,600 20.0 % 161,994 26,600 20.0 % 60,598 Clear Spring 11,210 20.0 % 10,944 11,210 20.0 % 10,645 Other 24,963 ~30% 20,233 24,963 ~30% 20,436 $ 299,823 $ 516,795 $ 266,823 $ 326,277 (1) We own 20.0% of the common shares in Monument Re as well as different classes of preferred shares which have fixed dividend yields.
Funds Held, Directly Managed, Carrying Values of Assets	The following table summarizes the components of the funds held - directly managed: September 30, 2020 December 31, 2019 Fixed maturity investments, trading $ 1,054,201 $ 1,173,345 Cash and cash equivalents 6,432 10,296 Other assets 6,006 3,911 $ 1,066,639 $ 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: September 30, 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 $ 106,768 $ 861,511 $ 968,279 $ 185,859 $ 940,194 $ 1,126,053 Net unrealized gains (losses): Change in fair value - fair value option accounting 9,077 — 9,077 5,438 — 5,438 Change in fair value - embedded derivative accounting — 76,845 76,845 — 41,854 41,854 Fixed maturity investments within funds held - directly managed, at fair value $ 115,845 $ 938,356 $ 1,054,201 $ 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Fixed maturity investments $ 47,275 $ 54,085 $ 153,554 $ 163,246 Short-term investments and cash and cash equivalents 826 3,526 4,203 11,430 Funds held 8,346 10,091 32,715 18,901 Funds held - directly managed 7,703 9,381 27,204 28,742 Investment income from fixed maturities and cash and cash equivalents 64,150 77,083 217,676 222,319 Equity investments 4,771 4,416 14,496 11,218 Other investments 6,000 2,642 19,384 7,259 Investment income from equities and other investments 10,771 7,058 33,880 18,477 Gross investment income 74,921 84,141 251,556 240,796 Investment expenses (2,791) (2,639) (10,269) (9,372) Net investment income $ 72,130 $ 81,502 $ 241,287 $ 231,424
Realized Gain (Loss) on Investments	Components of net realized and unrealized gains were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Net realized gains (losses) on sale: Gross realized gains on fixed maturity securities, AFS $ 9,871 $ 44 $ 19,995 $ 4,493 Gross realized losses on fixed maturity securities, AFS (786) (10) (7,379) (302) Credit recoveries (losses) on fixed maturity securities, AFS 2,248 — (389) — Net realized gains on fixed maturity securities, trading 30,531 25,245 87,911 45,636 Net realized gains on funds held - directly managed 3,292 1,991 5,545 629 Net realized gains (losses) on equity investments 8,286 (3,881) 9,165 (1,213) Net realized investment gains (losses) on derivatives 46 — 46 — Total net realized gains on sale $ 53,488 $ 23,389 $ 114,894 $ 49,243 Net unrealized gains (losses): Fixed maturity securities, trading $ 14,324 $ 86,840 $ 58,795 $ 413,175 Fixed maturity securities in funds held - directly managed portfolios 7,814 20,895 42,619 95,124 Equity investments 4,210 10,057 (48,409) 31,266 Other Investments 420,169 3,879 670,653 269,681 Total net unrealized gains 446,517 121,671 723,658 809,246 Net realized and unrealized gains $ 500,005 $ 145,060 $ 838,552 $ 858,489
Unrealized Gain (Loss) on Investments	Components of net realized and unrealized gains were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Net realized gains (losses) on sale: Gross realized gains on fixed maturity securities, AFS $ 9,871 $ 44 $ 19,995 $ 4,493 Gross realized losses on fixed maturity securities, AFS (786) (10) (7,379) (302) Credit recoveries (losses) on fixed maturity securities, AFS 2,248 — (389) — Net realized gains on fixed maturity securities, trading 30,531 25,245 87,911 45,636 Net realized gains on funds held - directly managed 3,292 1,991 5,545 629 Net realized gains (losses) on equity investments 8,286 (3,881) 9,165 (1,213) Net realized investment gains (losses) on derivatives 46 — 46 — Total net realized gains on sale $ 53,488 $ 23,389 $ 114,894 $ 49,243 Net unrealized gains (losses): Fixed maturity securities, trading $ 14,324 $ 86,840 $ 58,795 $ 413,175 Fixed maturity securities in funds held - directly managed portfolios 7,814 20,895 42,619 95,124 Equity investments 4,210 10,057 (48,409) 31,266 Other Investments 420,169 3,879 670,653 269,681 Total net unrealized gains 446,517 121,671 723,658 809,246 Net realized and unrealized gains $ 500,005 $ 145,060 $ 838,552 $ 858,489
Reconciliation to Comprehensive Income	The following table provides a reconciliation of the gross realized gains and losses and credit recoveries (losses) on our AFS fixed maturity debt securities that arose during the three and nine months ended September 30, 2020 within our continuing and discontinued operations and the offsetting reclassification adjustments included within our consolidated statements of comprehensive income: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Included within continuing operations: Gross realized gains on fixed maturity securities, AFS $ 9,871 $ 44 $ 19,995 $ 4,493 Gross realized losses on fixed maturity securities, AFS (786) (10) (7,379) (302) Included within discontinued operations: Gross realized gains on fixed maturity securities, AFS 489 12 1,025 12 Gross realized losses on fixed maturity securities, AFS (86) (12) (143) (12) Total reclassification adjustment $ 9,488 $ 34 $ 13,498 $ 4,191 Included within continuing operations: Credit recoveries (losses) on fixed maturity securities, AFS $ 2,248 $ — $ (389) $ — Included within discontinued operations: Credit recoveries (losses) on fixed maturity securities, AFS 131 — 318 — Total reclassification adjustment $ 2,379 $ — $ (71) $ —
Schedule of Restricted Assets	The carrying value of our restricted assets, including restricted cash of $556.7 million and $346.9 million, as of September 30, 2020 and December 31, 2019, respectively, was as follows: September 30, 2020 December 31, 2019 Collateral in trust for third party agreements $ 5,189,537 $ 4,103,847 Assets on deposit with regulatory authorities 276,941 309,659 Collateral for secured letter of credit facilities 121,700 132,670 Funds at Lloyd's (1) 546,996 639,316 $ 6,135,174 $ 5,185,492

Derivative and Hedging Instru_2

Derivative and Hedging Instruments (Tables)	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Estimated Fair Value and Unrealized Gains (Losses) on Derivative Instruments	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: September 30, 2020 December 31, 2019 Fair Value Fair Value Gross Notional Amount Assets Liabilities Gross Notional Amount Assets Liabilities Foreign currency forward - AUD $ 68,847 $ 282 $ — $ 64,620 $ 52 $ 2,033 Foreign currency forward - EUR 140,663 839 — 112,284 246 1,635 Foreign currency forward - GBP 329,245 5,664 — 318,387 344 7,784 Total qualifying hedges $ 538,755 $ 6,785 $ — $ 495,291 $ 642 $ 11,452 The following table presents the net gains and losses deferred in the cumulative translation adjustment ("CTA") account, which is a component of AOCI, in shareholders' equity, relating to our foreign currency forward exchange rate contracts: Amount of Gains (Losses) Deferred in AOCI Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Foreign currency forward - AUD $ (2,813) $ 1,673 $ (1,777) $ 1,819 Foreign currency forward - EUR (5,525) 4,780 (6,001) 5,076 Foreign currency forward - GBP (11,315) 8,260 10,002 6,669 Net gains (losses) on qualifying derivative hedges $ (19,653) $ 14,713 $ 2,224 $ 13,564 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 exchange rate hedging relationships: September 30, 2020 December 31, 2019 Fair Value Fair Value Gross Notional Amount Assets Liabilities Gross Notional Amount Assets Liabilities Foreign currency forward - AUD $ 19,076 $ 145 $ 81 $ 913 $ 839 $ 892 Foreign currency forward - CAD 52,212 525 89 66,266 10 1,482 Foreign currency forward - EUR 22,272 — 132 74,444 507 1,440 Foreign currency forward - GBP 43,254 744 — 11,940 13 292 Total non-qualifying hedges $ 136,814 $ 1,414 $ 302 $ 153,563 $ 1,369 $ 4,106 The following table presents 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Foreign currency forward - AUD $ 13 $ 1,148 $ (432) $ 1,710 Foreign currency forward - CAD (1,171) 1,582 1,600 (910) Foreign currency forward - EUR (817) 2,473 135 3,344 Foreign currency forward - GBP (2,219) 10,659 (719) $ 12,970 Net gains (losses) on non-qualifying hedges $ (4,194) $ 15,862 $ 584 $ 17,114 The following table presents the gross notional amounts and estimated fair values recorded within other assets and other liabilities related to our credit default swaps, government bond futures contracts and currency forward contracts: September 30, 2020 Fair Value Gross Notional Amount Assets Liabilities Credit default swaps $ 7,865 $ — $ 169 Futures contracts - long positions 48,051 100 — Futures contracts - short positions (33,318) — 85 Currency forward contracts - long positions 1,508 12 — Currency forward contracts - short positions (1,819) — 29 Total $ 22,287 $ 112 $ 283
Derivative Instruments, Gain (Loss)	The following table presents the amounts of the net gains included in earnings related to our credit default swaps, government bond futures contracts and currency forward contracts: Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Credit default swaps $ 106 $ 106 Futures contracts (6) (43) Currency forward contracts (43) 123 Total net gains $ 57 $ 186

Reinsurance Balances Recovera_2

Reinsurance Balances Recoverable on Paid and Unpaid Losses (Tables)	9 Months Ended
	Sep. 30, 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: September 30, 2020 Non-life StarStone Total Recoverable from reinsurers on unpaid: Outstanding losses $ 858,988 $ 258,215 $ 1,117,203 IBNR 439,594 143,073 582,667 ULAE 7,674 — 7,674 Fair value adjustments - acquired companies (11,986) (1,378) (13,364) Fair value adjustments - fair value option (27,029) — (27,029) Total reinsurance reserves recoverable 1,267,241 399,910 1,667,151 Paid losses recoverable 136,548 77,957 214,505 Total $ 1,403,789 $ 477,867 $ 1,881,656 Reconciliation to Consolidated Balance Sheet: Reinsurance balances recoverable on paid and unpaid losses $ 860,628 $ 477,867 $ 1,338,495 Reinsurance balances recoverable on paid and unpaid losses - fair value option 543,161 — 543,161 Total $ 1,403,789 $ 477,867 $ 1,881,656 December 31, 2019 Non-life Atrium StarStone Total Recoverable from reinsurers on unpaid: Outstanding losses $ 972,293 $ 9,011 $ 264,131 $ 1,245,435 IBNR 673,059 19,286 93,185 785,530 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 28,816 355,194 1,927,624 Paid losses recoverable 181,375 1,541 70,594 253,510 Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 Reconciliation to Consolidated Balance Sheet: Reinsurance balances recoverable on paid and unpaid losses $ 1,029,471 $ 30,357 $ 425,788 $ 1,485,616 Reinsurance balances recoverable on paid and unpaid losses - fair value option 695,518 — — 695,518 Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 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. September 30, 2020 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,429,984 $ 57,465 $ 1,372,519 4.0 % Reinsurers rated below A-, secured 419,431 — 419,431 — % Reinsurers rated below A-, unsecured 167,358 77,652 89,706 46.4 % Total $ 2,016,773 $ 135,117 $ 1,881,656 6.7 % December 31, 2019 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,731,270 $ 43,427 $ 1,687,843 2.5 % Reinsurers rated below A-, secured 463,840 — 463,840 — % Reinsurers rated below A-, unsecured 133,663 104,212 29,451 78.0 % Total $ 2,328,773 $ 147,639 $ 2,181,134 6.3 % The following table provides a summary of premiums written and earned by segment and for our other activities: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Premiums Premiums Premiums Premiums Premiums Premiums Premiums Premiums Non-life Run-off Gross $ 3,535 $ 20,426 $ 301 $ 27,190 $ 1,707 $ 52,899 $ (24,785) $ 166,707 Ceded (111) (2,950) (4,109) (10,353) 690 (8,876) (1,610) (24,726) Net $ 3,424 $ 17,476 $ (3,808) $ 16,837 $ 2,397 $ 44,023 $ (26,395) $ 141,981 Atrium Gross $ 49,083 $ 48,690 $ 48,746 $ 48,340 $ 155,551 $ 144,675 $ 146,519 $ 133,610 Ceded (2,580) (6,264) (4,961) (5,427) (19,458) (16,492) (19,273) (13,745) Net $ 46,503 $ 42,426 $ 43,785 $ 42,913 $ 136,093 $ 128,183 $ 127,246 $ 119,865 StarStone Gross $ 58,566 $ 123,813 $ 110,586 $ 151,895 $ 300,135 $ 362,638 $ 363,352 $ 409,135 Ceded (15,228) (27,697) (34,566) (40,146) (73,069) (86,072) (72,269) (69,142) Net $ 43,338 $ 96,116 $ 76,020 $ 111,749 $ 227,066 $ 276,566 $ 291,083 $ 339,993 Other Gross $ 293 $ 5,705 $ (2,498) $ 4,338 $ 3,237 $ 15,173 $ (1,174) $ 17,024 Ceded 1 1 (5) (35) 1 1 (23) (152) Net $ 294 $ 5,706 $ (2,503) $ 4,303 $ 3,238 $ 15,174 $ (1,197) $ 16,872 Total Gross $ 111,477 $ 198,634 $ 157,135 $ 231,763 $ 460,630 $ 575,385 $ 483,912 $ 726,476 Ceded (17,918) (36,910) (43,641) (55,961) (91,836) (111,439) (93,175) (107,765) Total $ 93,559 $ 161,724 $ 113,494 $ 175,802 $ 368,794 $ 463,946 $ 390,737 $ 618,711
Reinsurance Balances Recoverable by Reinsurer	September 30, 2020 Non-life StarStone Total % of Top 10 reinsurers $ 828,479 $ 344,444 $ 1,172,923 62.3 % Other reinsurers > $1 million 556,623 132,049 688,672 36.6 % Other reinsurers < $1 million 18,687 1,374 20,061 1.1 % Total $ 1,403,789 $ 477,867 $ 1,881,656 100.0 % December 31, 2019 Non-life Atrium StarStone Total % of Top 10 reinsurers $ 1,154,110 $ 22,051 $ 295,443 $ 1,471,604 67.4 % Other reinsurers > $1 million 551,636 7,761 129,335 688,732 31.6 % Other reinsurers < $1 million 19,243 545 1,010 20,798 1.0 % Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 100.0 % September 30, 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 $ 910,751 $ 1,199,479 Non-rated reinsurers in top 10 (1) 262,172 272,125 Total top 10 reinsurance recoverables $ 1,172,923 $ 1,471,604 Single reinsurers that represent 10% or more of total reinsurance balance recoverables as of September 30, 2020: Hannover Ruck SE (2) $ — $ 259,077 Lloyd's Syndicates (3) $ 346,601 $ 396,246 (1) The reinsurance balances recoverable from the two non-rated top 10 reinsurers was comprised of: • $183.4 million and $190.8 million as of September 30, 2020 and December 31, 2019 respectively, due from a US state backed reinsurer that is supported by assessments on active auto writers operating within the state; and • $78.8 million and $81.4 million as of September 30, 2020 and December 31, 2019 respectively, due from a reinsurer who has provided us with security in the form of pledged assets in trust for the full amount of the recoverable balance. (2) Hannover Ruck SE is rated AA- by Standard & Poor’s and A+ by A.M. Best. The transaction described in Note 3 - "Significant New Business" had the effect of moving this reinsurer to be less than 10%. (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 and nine months ended September 30, 2020: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Allowance for estimated uncollectible reinsurance, beginning of period $ 143,653 $ 147,639 Cumulative effect of change in accounting principle — (195) Effect of exchange rate movement 745 (701) Current period change in the allowance 815 (718) Write-offs charged against the allowance (9,625) (10,225) Recoveries collected (471) (683) Allowance for estimated uncollectible reinsurance, end of period $ 135,117 $ 135,117

Deferred Charge Assets (Tables)

Deferred Charge Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Insurance [Abstract]
Deferred Policy Acquisition Costs	The following table presents a reconciliation of the deferred charge assets: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Beginning carrying value $ 258,516 $ 99,094 $ 272,462 $ 86,585 Recorded during the period — 85,183 11,746 108,689 Amortization (10,316) (17,009) (36,008) (28,006) Ending carrying value $ 248,200 $ 167,268 $ 248,200 $ 167,268

Losses and Loss Adjustment Ex_2

Losses and Loss Adjustment Expenses (Tables)	9 Months Ended
	Sep. 30, 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: September 30, 2020 Non-life StarStone Other Total Outstanding losses $ 4,461,854 $ 698,118 $ 10,479 $ 5,170,451 IBNR 4,360,063 611,986 15,817 4,987,866 Fair value adjustments - acquired companies (147,500) (339) — (147,839) Fair value adjustments - fair value option (81,299) — — (81,299) ULAE 330,472 41,233 — 371,705 Total $ 8,923,590 $ 1,350,998 $ 26,296 $ 10,300,884 Reconciliation to Consolidated Balance Sheet: Loss and loss adjustment expenses $ 6,500,912 $ 1,350,998 $ 26,296 $ 7,878,206 Loss and loss adjustment expenses, at fair value 2,422,678 — — 2,422,678 Total $ 8,923,590 $ 1,350,998 $ 26,296 $ 10,300,884 December 31, 2019 Non-life Atrium StarStone Other Total Outstanding losses $ 4,407,082 $ 89,141 $ 743,829 $ 9,512 $ 5,249,564 IBNR 3,945,407 136,543 556,135 13,565 4,651,650 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 18,852 — 352,634 Total $ 8,295,361 $ 231,672 $ 1,318,294 $ 23,077 $ 9,868,404 Reconciliation to Consolidated Balance Sheet: Loss and loss adjustment expenses $ 5,674,239 $ 231,672 $ 1,318,294 $ 23,077 $ 7,247,282 Loss and loss adjustment expenses, at fair value 2,621,122 — — — 2,621,122 Total $ 8,295,361 $ 231,672 $ 1,318,294 $ 23,077 $ 9,868,404 The table below provides a consolidated reconciliation of the beginning and ending liability for losses and LAE: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 10,593,436 $ 9,354,891 $ 9,868,404 $ 9,048,796 Less: reinsurance reserves recoverable 1,858,161 1,873,766 1,927,624 1,708,272 Less: deferred charge assets on retroactive reinsurance 258,516 99,094 272,462 86,585 Less: cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible reinsurance balances (1) — — 643 — Net balance as of beginning of period 8,476,759 7,382,031 7,667,675 7,253,939 Net incurred losses and LAE: Current period 78,965 156,344 314,083 457,720 Prior periods 30,721 6,914 25,595 108,391 Total net incurred losses and LAE 109,686 163,258 339,678 566,111 Net paid losses: Current period (17,194) (36,733) (32,304) (107,679) Prior periods (344,060) (397,514) (1,070,063) (1,255,903) Total net paid losses (361,254) (434,247) (1,102,367) (1,363,582) Effect of exchange rate movement 99,129 (83,277) (6,139) (95,270) Acquired on purchase of subsidiaries — — — 686 Assumed business 280,497 445,000 1,705,970 1,110,881 Reclassification to assets and liabilities held-for-sale (219,284) — (219,284) — Net balance as of September 30 8,385,533 7,472,765 8,385,533 7,472,765 Plus: reinsurance reserves recoverable (2) 1,667,151 1,876,613 1,667,151 1,876,613 Plus: deferred charge assets on retroactive reinsurance 248,200 167,268 248,200 167,268 Balance as of September 30 $ 10,300,884 $ 9,516,646 $ 10,300,884 $ 9,516,646 (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. This amount excludes $0.4 million related to the adoption impact of ASU 2016-13 (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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 8,979,234 $ 7,803,663 $ 8,295,361 $ 7,540,662 Less: reinsurance reserves recoverable 1,429,489 1,534,427 1,543,614 1,366,123 Less: deferred charge assets on retroactive insurance 258,516 99,094 272,462 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 7,291,229 6,170,142 6,479,988 6,087,954 Net incurred losses and LAE: Current period 8,218 23,845 24,153 107,291 Prior periods 26,040 6,738 39,545 28,226 Total net incurred losses and LAE 34,258 30,583 63,698 135,517 Net paid losses: Current period (739) (14,374) (1,777) (53,265) Prior periods (283,143) (274,071) (824,473) (913,352) Total net paid losses (283,882) (288,445) (826,250) (966,617) Effect of exchange rate movement 86,047 (73,231) (15,257) (84,372) Acquired on purchase of subsidiaries — — — 686 Assumed business 280,497 445,000 1,705,970 1,110,881 Reclassification to assets and liabilities held-for-sale — — — — Net balance as of September 30 7,408,149 6,284,049 7,408,149 6,284,049 Plus: reinsurance reserves recoverable (2) 1,267,241 1,488,374 1,267,241 1,488,374 Plus: deferred charge assets on retroactive reinsurance 248,200 167,268 248,200 167,268 Balance as of September 30 $ 8,923,590 $ 7,939,691 $ 8,923,590 $ 7,939,691 (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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 239,731 $ 222,576 $ 231,672 $ 241,284 Less: reinsurance reserves recoverable 27,250 29,606 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 212,481 192,970 202,005 202,516 Net incurred losses and LAE: Current period 23,129 27,093 70,075 63,189 Prior periods (1,134) 1,307 (4,072) (4,527) Total net incurred losses and LAE 21,995 28,400 66,003 58,662 Net paid losses: Current period (7,717) (9,387) (17,004) (24,531) Prior periods (9,472) (10,618) (31,412) (35,564) Total net paid losses (17,189) (20,005) (48,416) (60,095) Effect of exchange rate movement 1,997 (1,405) (308) (1,123) Reclassification to assets and liabilities held-for-sale (219,284) — (219,284) — Net balance as of September 30 — 199,960 — 199,960 Plus: reinsurance reserves recoverable (2) — 31,719 — 31,719 Balance as of September 30 $ — $ 231,679 $ — $ 231,679 (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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 1,349,763 $ 1,305,026 $ 1,318,294 $ 1,247,989 Less: reinsurance reserves recoverable 401,422 309,733 355,194 303,381 Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance (1) — — 495 — Net balance as of beginning of period 948,341 995,293 962,605 944,608 Net incurred losses and LAE: Current period 44,734 101,808 208,414 274,070 Prior periods 3,656 (1,180) (11,155) 84,794 Total net incurred losses and LAE 48,390 100,628 197,259 358,864 Net paid losses: Current period (7,755) (11,653) (12,142) (27,624) Prior periods (48,972) (111,195) (206,058) (301,641) Total net paid losses (56,727) (122,848) (218,200) (329,265) Effect of exchange rate movement 11,084 (8,641) 9,424 (9,775) Net balance as of September 30 951,088 964,432 951,088 964,432 Plus: reinsurance reserves recoverable (2) 399,910 356,520 399,910 356,520 Balance as of September 30 $ 1,350,998 $ 1,320,952 $ 1,350,998 $ 1,320,952 (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. This amount excludes $0.4 million related to the adoption impact of ASU 2016-13 (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 September 30, 2020 Non-life Run-off Atrium StarStone Other Total Net losses paid $ 283,882 $ 17,189 $ 56,727 $ 3,456 $ 361,254 Net change in case and LAE reserves (49,887) 2,701 5,456 103 (41,627) Net change in IBNR reserves (221,800) 2,386 (8,579) 1,484 (226,509) Increase in estimates of net ultimate losses 12,195 22,276 53,604 5,043 93,118 Reduction in provisions for unallocated LAE (14,605) (29) (5,020) — (19,654) Amortization of deferred charge assets 10,316 — — — 10,316 Amortization of fair value adjustments 5,310 (252) (194) — 4,864 Changes in fair value - fair value option 21,042 — — — 21,042 Net incurred losses and LAE $ 34,258 $ 21,995 $ 48,390 $ 5,043 $ 109,686 Three Months Ended September 30, 2019 Non-life Atrium StarStone Other Total Net losses paid $ 288,445 $ 20,005 $ 122,848 $ 2,949 $ 434,247 Net change in case and LAE reserves (173,104) (91) (17,860) 944 (190,111) Net change in IBNR reserves (148,521) 8,702 (4,713) (246) (144,778) Increase (reduction) in estimates of net ultimate losses (33,180) 28,616 100,275 3,647 99,358 Reduction in provisions for unallocated LAE (12,158) — (188) — (12,346) Amortization of deferred charge assets 17,009 — — — 17,009 Amortization of fair value adjustments 17,538 (216) 541 — 17,863 Changes in fair value - fair value option 41,374 — — — 41,374 Net incurred losses and LAE $ 30,583 $ 28,400 $ 100,628 $ 3,647 $ 163,258 Nine Months Ended September 30, 2020 Non-life Run-off Atrium StarStone Other Total Net losses paid $ 826,250 $ 48,416 $ 218,200 $ 9,501 $ 1,102,367 Net change in case and LAE reserves (300,573) 3,635 (60,887) 965 (356,860) Net change in IBNR reserves (581,979) 14,227 17,032 2,252 (548,468) Increase (reduction) in estimates of net ultimate losses (56,302) 66,278 174,345 12,718 197,039 Increase (reduction) in provisions for unallocated LAE (34,509) (29) 23,475 — (11,063) Amortization of deferred charge assets 36,008 — — — 36,008 Amortization of fair value adjustments 21,653 (246) (561) — 20,846 Changes in fair value - fair value option 96,848 — — — 96,848 Net incurred losses and LAE $ 63,698 $ 66,003 $ 197,259 $ 12,718 $ 339,678 Nine Months Ended September 30, 2019 Non-life Atrium StarStone Other Total Net losses paid $ 966,617 $ 60,095 $ 329,265 $ 7,605 $ 1,363,582 Net change in case and LAE reserves (370,639) (245) 13,508 2,298 (355,078) Net change in IBNR reserves (619,648) (1,916) 15,042 3,165 (603,357) Increase (reduction) in estimates of net ultimate losses (23,670) 57,934 357,815 13,068 405,147 Increase (reduction) in provisions for unallocated LAE (38,229) — 739 — (37,490) Amortization of deferred charge assets 28,006 — — — 28,006 Amortization of fair value adjustments 34,033 728 310 — 35,071 Changes in fair value - fair value option 135,377 — — — 135,377 Net incurred losses and LAE $ 135,517 $ 58,662 $ 358,864 $ 13,068 $ 566,111 Net incurred losses and LAE in the Non-life Run-off segment were as follows: Three Months Ended September 30, 2020 2019 Prior Current Total Prior Current Total Net losses paid $ 283,143 $ 739 $ 283,882 $ 274,071 $ 14,374 $ 288,445 Net change in case and LAE reserves (49,854) (33) (49,887) (175,830) 2,726 (173,104) Net change in IBNR reserves (229,312) 7,512 (221,800) (155,315) 6,794 (148,521) Increase (reduction) in estimates of net ultimate losses 3,977 8,218 12,195 (57,074) 23,894 (33,180) Reduction in provisions for unallocated LAE (14,605) — (14,605) (12,109) (49) (12,158) Amortization of deferred charge assets 10,316 — 10,316 17,009 — 17,009 Amortization of fair value adjustments 5,310 — 5,310 17,538 — 17,538 Changes in fair value - fair value option 21,042 — 21,042 41,374 — 41,374 Net incurred losses and LAE $ 26,040 $ 8,218 $ 34,258 $ 6,738 $ 23,845 $ 30,583 Nine Months Ended September 30, 2020 2019 Prior Current Total Prior Current Total Net losses paid $ 824,473 $ 1,777 $ 826,250 $ 913,352 $ 53,265 $ 966,617 Net change in case and LAE reserves (301,382) 809 (300,573) (394,780) 24,141 (370,639) Net change in IBNR reserves (603,546) 21,567 (581,979) (649,053) 29,405 (619,648) Increase (reduction) in estimates of net ultimate losses (80,455) 24,153 (56,302) (130,481) 106,811 (23,670) Increase (reduction) in provisions for unallocated LAE (34,509) — (34,509) (38,709) 480 (38,229) Amortization of deferred charge assets 36,008 — 36,008 28,006 — 28,006 Amortization of fair value adjustments 21,653 — 21,653 34,033 — 34,033 Changes in fair value - fair value option 96,848 — 96,848 135,377 — 135,377 Net incurred losses and LAE $ 39,545 $ 24,153 $ 63,698 $ 28,226 $ 107,291 $ 135,517 Net incurred losses and LAE in the Atrium segment were as follows: Three Months Ended September 30, 2020 2019 Prior Current Total Prior Current Total Net losses paid $ 9,472 $ 7,717 $ 17,189 $ 10,618 $ 9,387 $ 20,005 Net change in case and LAE reserves (2,292) 4,993 2,701 (2,860) 2,769 (91) Net change in IBNR reserves (8,110) 10,496 2,386 (6,235) 14,937 8,702 Increase (reduction) in estimates of net ultimate losses (930) 23,206 22,276 1,523 27,093 28,616 Increase (reduction) in provisions for unallocated LAE 48 (77) (29) — — — Amortization of fair value adjustments (252) — (252) (216) — (216) Net incurred losses and LAE $ (1,134) $ 23,129 $ 21,995 $ 1,307 $ 27,093 $ 28,400 Nine Months Ended September 30, 2020 2019 Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 31,412 $ 17,004 $ 48,416 $ 35,564 $ 24,531 $ 60,095 Net change in case and LAE reserves (9,517) 13,152 3,635 (13,032) 12,787 (245) Net change in IBNR reserves (25,769) 39,996 14,227 (27,787) 25,871 (1,916) Increase (reduction) in estimates of net ultimate losses (3,874) 70,152 66,278 (5,255) 63,189 57,934 Increase (reduction) in provisions for unallocated LAE 48 (77) (29) — — — Amortization of fair value adjustments (246) — (246) 728 — 728 Net incurred losses and LAE $ (4,072) $ 70,075 $ 66,003 $ (4,527) $ 63,189 $ 58,662 Net incurred losses and LAE in the StarStone segment were as follows: Three Months Ended September 30, 2020 2019 Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 48,972 $ 7,755 $ 56,727 $ 111,195 $ 11,653 $ 122,848 Net change in case and LAE reserves (20,068) 25,524 5,456 (8,866) (8,994) (17,860) Net change in IBNR reserves (24,755) 16,176 (8,579) (101,938) 97,225 (4,713) Increase in estimates of net ultimate losses 4,149 49,455 53,604 391 99,884 100,275 Increase (reduction) in provisions for unallocated LAE (299) (4,721) (5,020) (2,112) 1,924 (188) Amortization of fair value adjustments (194) — (194) 541 — 541 Net incurred losses and LAE $ 3,656 $ 44,734 $ 48,390 $ (1,180) $ 101,808 $ 100,628 Nine Months Ended September 30, 2020 2019 Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 206,058 $ 12,142 $ 218,200 $ 301,641 $ 27,624 $ 329,265 Net change in case and LAE reserves (85,798) 24,911 (60,887) (22,538) 36,046 13,508 Net change in IBNR reserves (130,738) 147,770 17,032 (192,034) 207,076 15,042 Increase (reduction) in estimates of net ultimate losses (10,478) 184,823 174,345 87,069 270,746 357,815 Increase (reduction) in provisions for unallocated LAE (116) 23,591 23,475 (2,585) 3,324 739 Amortization of fair value adjustments (561) — (561) 310 — 310 Net incurred losses and LAE $ (11,155) $ 208,414 $ 197,259 $ 84,794 $ 274,070 $ 358,864

Defendant Asbestos and Enviro_2

Defendant Asbestos and Environmental Liabilities (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2020 and December 31, 2019 were as follows: September 30, 2020 December 31, 2019 Defendant asbestos and environmental liabilities: Defendant asbestos liabilities $ 980,678 $ 1,100,593 Defendant environmental liabilities 8,214 10,279 Estimated future expenses 45,509 51,637 Fair value adjustments (280,364) (314,824) Defendant asbestos and environmental liabilities $ 754,037 $ 847,685 Insurance balances recoverable: Insurance recoveries related to defendant asbestos and environmental liabilities (net of allowance: 2020 - $5,907) 447,800 549,593 Fair value adjustments (82,512) (100,738) Insurance balances recoverable $ 365,288 $ 448,855 Net liabilities relating to defendant asbestos and environmental exposures $ 388,749 $ 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 and nine months ended September 30, 2020 and 2019: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance as of beginning of period $ 808,062 $ 184,264 $ 847,685 $ 203,320 Less: Insurance balances recoverable 428,277 122,236 448,855 135,808 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 379,785 62,028 401,997 67,512 Total net paid claims 52,891 (2,204) 51,977 (1,326) Amounts recorded in other (income) expense: Reduction in estimates of ultimate net liabilities (48,439) — (75,332) (4,259) Reduction in estimated future expenses (3,124) (800) (6,127) (3,104) Amortization of fair value adjustments 7,636 102 16,234 303 Total other (income) expense (43,927) (698) (65,225) (7,060) Net balance as at September 30 388,749 59,126 388,749 59,126 Plus: Insurance balances recoverable (2) 365,288 121,237 365,288 121,237 Balance as at September 30 $ 754,037 $ 180,363 $ 754,037 $ 180,363 (1) The Company adopted ASU 2016-13 (2) Net of allowance for estimated uncollectible insurance balances.
Reconciliation of Allowance for Estimated Uncollectible Insurance Balances	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 and nine months ended September 30, 2020: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Allowance for estimated uncollectible insurance balances, beginning of period $ 8,346 $ 3,818 Cumulative effect of change in accounting principle — 3,167 Current period change in the allowance (2,439) (1,078) Allowance for estimated uncollectible insurance balances, end of period $ 5,907 $ 5,907

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 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: September 30, 2020 Quoted Prices in Significant Significant Fair Value Based on NAV as Practical Expedient Total Fair Investments: Short-term and fixed maturity investments: U.S. government and agency $ — $ 789,630 $ — $ — $ 789,630 U.K. government — 114,777 — — 114,777 Other government — 490,447 — — 490,447 Corporate — 5,679,909 — — 5,679,909 Municipal — 161,839 — — 161,839 Residential mortgage-backed — 529,239 — — 529,239 Commercial mortgage-backed — 843,119 — — 843,119 Asset-backed — 613,663 — — 613,663 $ — $ 9,222,623 $ — $ — $ 9,222,623 Other assets included within funds held - directly managed — 12,438 — — 12,438 Equities: Publicly traded equity investments $ 282,904 $ 21,028 $ — $ — $ 303,932 Exchange-traded funds 78,182 — — — 78,182 Privately held equity investments — — 271,045 — 271,045 $ 361,086 $ 21,028 $ 271,045 $ — $ 653,159 Other investments: Hedge funds $ — $ — $ — $ 2,087,091 $ 2,087,091 Fixed income funds — 428,645 — 255,386 684,031 Equity funds — 4,558 — 285,571 290,129 Private equity funds — — — 320,455 320,455 CLO equities — 84,532 — — 84,532 CLO equity funds — — — 140,458 140,458 Private credit funds — — 10,000 80,476 90,476 Other — — 314 7,384 7,698 $ — $ 517,735 $ 10,314 $ 3,176,821 $ 3,704,870 Total Investments $ 361,086 $ 9,773,824 $ 281,359 $ 3,176,821 $ 13,593,090 Cash and cash equivalents $ 270,267 $ 139,140 $ — $ — $ 409,407 Reinsurance balances recoverable on paid and unpaid losses: $ — $ — $ 543,161 $ — $ 543,161 Other Assets: Derivatives qualifying as hedges $ — $ 6,785 $ — $ — $ 6,785 Derivatives not qualifying as hedges — 1,526 — — 1,526 Derivative instruments $ — $ 8,311 $ — $ — $ 8,311 Losses and LAE: $ — $ — $ 2,422,678 $ — $ 2,422,678 Other Liabilities: Derivatives qualifying as hedges $ — $ — $ — $ — $ — Derivatives not qualifying as hedges — 585 — — 585 Derivative instruments $ — $ 585 $ — $ — $ 585 December 31, 2019 Quoted Prices in Significant Significant Fair Value Based on NAV as Practical Expedient Total Fair Investments: Short-term and fixed maturity investments: U.S. government and agency $ — $ 696,077 $ — $ — $ 696,077 U.K government — 161,772 — — 161,772 Other government — 702,856 — — 702,856 Corporate — 5,448,270 — — 5,448,270 Municipal — 140,687 — — 140,687 Residential mortgage-backed — 400,914 — — 400,914 Commercial mortgage-backed — 813,746 — — 813,746 Asset-backed — 670,235 — — 670,235 $ — $ 9,034,557 $ — $ — $ 9,034,557 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 — — 265,799 — 265,799 $ 430,357 $ 30,565 $ 265,799 $ — $ 726,721 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 — — — 323,496 323,496 CLO equities — — 87,555 — 87,555 CLO equity funds — — — 87,509 87,509 Other — 34 314 6,031 6,379 $ — $ 509,217 $ 87,869 $ 1,920,945 $ 2,518,031 Total Investments $ 430,357 $ 9,588,546 $ 353,668 $ 1,920,945 $ 12,293,516 Cash and cash equivalents $ 144,984 $ 222,191 $ — $ — $ 367,175 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 September 30, 2020 Privately-held Equities Other Investments Total Beginning fair value $ 271,000 $ 314 $ 271,314 Purchases — 10,000 10,000 Sales — — — Total realized and unrealized gains 45 — 45 Transfer out of Level 3 into Level 2 — — — Ending fair value $ 271,045 $ 10,314 $ 281,359 Three Months Ended September 30, 2019 Fixed maturity investments Privately-held Equities Other Investments Total Corporate Residential mortgage-backed Commercial mortgage-backed Asset-backed Beginning fair value $ 5,006 $ 102 $ 1,370 $ 25,839 $ 229,394 $ 50,452 $ 312,163 Purchases 82 — — — 3,691 22,619 26,392 Sales (116) — (176) (295) (2,016) (361) (2,964) Total realized and unrealized gains (losses) (103) (1) 148 (743) (2,378) (5,287) (8,364) Transfer into Level 3 from Level 2 277 — — — — — 277 Transfer out of Level 3 into Level 2 (2,865) (101) (1,340) (5,978) — — (10,284) Ending fair value $ 2,281 $ — $ 2 $ 18,823 $ 228,691 $ 67,423 $ 317,220 Nine Months Ended September 30, 2020 Privately-held Equities Other Investments Total Beginning fair value $ 265,799 $ 87,869 $ 353,668 Purchases 1,392 47,092 48,484 Sales — (539) (539) Total realized and unrealized gains (losses) 3,854 (40,368) (36,514) Transfer into Level 3 from Level 2 — — — Transfer out of Level 3 into Level 2 — (83,740) (83,740) Ending fair value $ 271,045 $ 10,314 $ 281,359 Nine Months Ended September 30, 2019 Fixed maturity investments Privately-held Equities Other Investments Total Corporate Residential mortgage-backed Commercial mortgage-backed Asset-backed Beginning fair value $ 37,386 $ — $ 7,389 $ 9,121 $ 228,710 $ 39,367 $ 321,973 Purchases 172 — — — 3,691 34,614 38,477 Sales (3,157) — (784) (625) (2,016) (361) (6,943) Total realized and unrealized gains (losses) 114 (1) 65 (4) (1,694) (6,197) (7,717) Transfer into Level 3 from Level 2 3,535 102 1,515 22,771 — — 27,923 Transfer out of Level 3 into Level 2 (35,769) (101) (8,183) (12,440) — — (56,493) Ending fair value $ 2,281 $ — $ 2 $ 18,823 $ 228,691 $ 67,423 $ 317,220 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 September 30, 2020 2019 Liability for losses and LAE Reinsurance balances recoverable Net Liability for losses and LAE Reinsurance balances recoverable Net Beginning fair value $ 2,454,539 $ 671,384 $ 1,783,155 $ 2,772,501 $ 743,304 $ 2,029,197 Assumed business 1,526 (180,972) 182,498 — — — Incurred losses and LAE: Reduction in estimates of ultimate losses (25,595) 56,702 (82,297) (7,386) 2,354 (9,740) Reduction in unallocated LAE (4,641) — (4,641) (6,724) — (6,724) Change in fair value 19,092 (1,950) 21,042 57,743 16,369 41,374 Total incurred losses and LAE (11,144) 54,752 (65,896) 43,633 18,723 24,910 Paid losses (86,745) (11,192) (75,553) (100,654) (21,816) (78,838) Effect of exchange rate movements 64,502 9,189 55,313 (56,836) (8,307) (48,529) Ending fair value $ 2,422,678 $ 543,161 $ 1,879,517 $ 2,658,644 $ 731,904 $ 1,926,740 The net assumed business of $182.5 million in the current period relates to the Hannover Re novation transaction disclosed in Note 3 - "Significant New Business." 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 2020 2019 Changes in fair value due to changes in: Duration $ 11,767 $ 3,850 Corporate bond yield 9,275 37,524 Change in fair value $ 21,042 $ 41,374 Nine Months Ended 2020 2019 Liability for losses and LAE Reinsurance balances recoverable on paid and unpaid losses Net Liability for losses and LAE Reinsurance balances recoverable on paid and unpaid losses Net Beginning fair value $ 2,621,122 $ 695,518 $ 1,925,604 $ 2,874,055 $ 739,591 $ 2,134,464 Assumed business 1,526 (180,972) 182,498 — — — Incurred losses and LAE: Reduction in estimates of ultimate losses (61,109) 48,580 (109,689) (20,342) 4,059 (24,401) Reduction in unallocated LAE (14,353) — (14,353) (15,076) — (15,076) Change in fair value 130,075 33,227 96,848 189,422 54,045 135,377 Total incurred losses and LAE 54,613 81,807 (27,194) 154,004 58,104 95,900 Paid losses (230,187) (49,627) (180,560) (308,267) (58,139) (250,128) Effect of exchange rate movements (24,396) (3,565) (20,831) (61,148) (7,652) (53,496) Ending fair value $ 2,422,678 $ 543,161 $ 1,879,517 $ 2,658,644 $ 731,904 $ 1,926,740 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: Nine Months Ended 2020 2019 Changes in fair value due to changes in: Duration $ 19,617 $ 18,736 Corporate bond yield 75,524 116,641 Weighted cost of capital (5,048) — Risk cost of capital 6,755 — Change in fair value $ 96,848 $ 135,377
Valuation Inputs and Techniques	The table below presents the quantitative information related to the fair value measurements for our privately held equity investments measured at fair value on a recurring basis using Level 3 inputs: Quantitative Information about Level 3 Fair Value Measurements Fair Value as of September 30, 2020 Valuation Techniques Unobservable Input Range (Average) (1) (in millions of U.S. dollars) $ 245.4 Transactional value Implied price per share at recent purchase transaction 13.50 - 13.85 $ 25.6 Cost as approximation of fair value Cost as approximation of fair value $ 271.0 (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 September 30, 2020 2019 Liability for losses and LAE Reinsurance balances recoverable Net Liability for losses and LAE Reinsurance balances recoverable Net Beginning fair value $ 2,454,539 $ 671,384 $ 1,783,155 $ 2,772,501 $ 743,304 $ 2,029,197 Assumed business 1,526 (180,972) 182,498 — — — Incurred losses and LAE: Reduction in estimates of ultimate losses (25,595) 56,702 (82,297) (7,386) 2,354 (9,740) Reduction in unallocated LAE (4,641) — (4,641) (6,724) — (6,724) Change in fair value 19,092 (1,950) 21,042 57,743 16,369 41,374 Total incurred losses and LAE (11,144) 54,752 (65,896) 43,633 18,723 24,910 Paid losses (86,745) (11,192) (75,553) (100,654) (21,816) (78,838) Effect of exchange rate movements 64,502 9,189 55,313 (56,836) (8,307) (48,529) Ending fair value $ 2,422,678 $ 543,161 $ 1,879,517 $ 2,658,644 $ 731,904 $ 1,926,740 The net assumed business of $182.5 million in the current period relates to the Hannover Re novation transaction disclosed in Note 3 - "Significant New Business." 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 2020 2019 Changes in fair value due to changes in: Duration $ 11,767 $ 3,850 Corporate bond yield 9,275 37,524 Change in fair value $ 21,042 $ 41,374 Nine Months Ended 2020 2019 Liability for losses and LAE Reinsurance balances recoverable on paid and unpaid losses Net Liability for losses and LAE Reinsurance balances recoverable on paid and unpaid losses Net Beginning fair value $ 2,621,122 $ 695,518 $ 1,925,604 $ 2,874,055 $ 739,591 $ 2,134,464 Assumed business 1,526 (180,972) 182,498 — — — Incurred losses and LAE: Reduction in estimates of ultimate losses (61,109) 48,580 (109,689) (20,342) 4,059 (24,401) Reduction in unallocated LAE (14,353) — (14,353) (15,076) — (15,076) Change in fair value 130,075 33,227 96,848 189,422 54,045 135,377 Total incurred losses and LAE 54,613 81,807 (27,194) 154,004 58,104 95,900 Paid losses (230,187) (49,627) (180,560) (308,267) (58,139) (250,128) Effect of exchange rate movements (24,396) (3,565) (20,831) (61,148) (7,652) (53,496) Ending fair value $ 2,422,678 $ 543,161 $ 1,879,517 $ 2,658,644 $ 731,904 $ 1,926,740 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: Nine Months Ended 2020 2019 Changes in fair value due to changes in: Duration $ 19,617 $ 18,736 Corporate bond yield 75,524 116,641 Weighted cost of capital (5,048) — Risk cost of capital 6,755 — Change in fair value $ 96,848 $ 135,377
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: September 30, 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) 7.92 years 7.82 years Internal model Duration - reinsurance balances recoverable (U) 7.71 years 8.68 years

Premiums Written and Earned (Ta

Premiums Written and Earned (Tables)	9 Months Ended
	Sep. 30, 2020
Insurance [Abstract]
Schedule of Net Premiums Written and Earned	The following tables provide the total reinsurance balances recoverable on paid and unpaid losses: September 30, 2020 Non-life StarStone Total Recoverable from reinsurers on unpaid: Outstanding losses $ 858,988 $ 258,215 $ 1,117,203 IBNR 439,594 143,073 582,667 ULAE 7,674 — 7,674 Fair value adjustments - acquired companies (11,986) (1,378) (13,364) Fair value adjustments - fair value option (27,029) — (27,029) Total reinsurance reserves recoverable 1,267,241 399,910 1,667,151 Paid losses recoverable 136,548 77,957 214,505 Total $ 1,403,789 $ 477,867 $ 1,881,656 Reconciliation to Consolidated Balance Sheet: Reinsurance balances recoverable on paid and unpaid losses $ 860,628 $ 477,867 $ 1,338,495 Reinsurance balances recoverable on paid and unpaid losses - fair value option 543,161 — 543,161 Total $ 1,403,789 $ 477,867 $ 1,881,656 December 31, 2019 Non-life Atrium StarStone Total Recoverable from reinsurers on unpaid: Outstanding losses $ 972,293 $ 9,011 $ 264,131 $ 1,245,435 IBNR 673,059 19,286 93,185 785,530 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 28,816 355,194 1,927,624 Paid losses recoverable 181,375 1,541 70,594 253,510 Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 Reconciliation to Consolidated Balance Sheet: Reinsurance balances recoverable on paid and unpaid losses $ 1,029,471 $ 30,357 $ 425,788 $ 1,485,616 Reinsurance balances recoverable on paid and unpaid losses - fair value option 695,518 — — 695,518 Total $ 1,724,989 $ 30,357 $ 425,788 $ 2,181,134 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. September 30, 2020 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,429,984 $ 57,465 $ 1,372,519 4.0 % Reinsurers rated below A-, secured 419,431 — 419,431 — % Reinsurers rated below A-, unsecured 167,358 77,652 89,706 46.4 % Total $ 2,016,773 $ 135,117 $ 1,881,656 6.7 % December 31, 2019 Gross Allowance for estimated uncollectible reinsurance Net Provisions as a Reinsurers rated A- or above $ 1,731,270 $ 43,427 $ 1,687,843 2.5 % Reinsurers rated below A-, secured 463,840 — 463,840 — % Reinsurers rated below A-, unsecured 133,663 104,212 29,451 78.0 % Total $ 2,328,773 $ 147,639 $ 2,181,134 6.3 % The following table provides a summary of premiums written and earned by segment and for our other activities: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Premiums Premiums Premiums Premiums Premiums Premiums Premiums Premiums Non-life Run-off Gross $ 3,535 $ 20,426 $ 301 $ 27,190 $ 1,707 $ 52,899 $ (24,785) $ 166,707 Ceded (111) (2,950) (4,109) (10,353) 690 (8,876) (1,610) (24,726) Net $ 3,424 $ 17,476 $ (3,808) $ 16,837 $ 2,397 $ 44,023 $ (26,395) $ 141,981 Atrium Gross $ 49,083 $ 48,690 $ 48,746 $ 48,340 $ 155,551 $ 144,675 $ 146,519 $ 133,610 Ceded (2,580) (6,264) (4,961) (5,427) (19,458) (16,492) (19,273) (13,745) Net $ 46,503 $ 42,426 $ 43,785 $ 42,913 $ 136,093 $ 128,183 $ 127,246 $ 119,865 StarStone Gross $ 58,566 $ 123,813 $ 110,586 $ 151,895 $ 300,135 $ 362,638 $ 363,352 $ 409,135 Ceded (15,228) (27,697) (34,566) (40,146) (73,069) (86,072) (72,269) (69,142) Net $ 43,338 $ 96,116 $ 76,020 $ 111,749 $ 227,066 $ 276,566 $ 291,083 $ 339,993 Other Gross $ 293 $ 5,705 $ (2,498) $ 4,338 $ 3,237 $ 15,173 $ (1,174) $ 17,024 Ceded 1 1 (5) (35) 1 1 (23) (152) Net $ 294 $ 5,706 $ (2,503) $ 4,303 $ 3,238 $ 15,174 $ (1,197) $ 16,872 Total Gross $ 111,477 $ 198,634 $ 157,135 $ 231,763 $ 460,630 $ 575,385 $ 483,912 $ 726,476 Ceded (17,918) (36,910) (43,641) (55,961) (91,836) (111,439) (93,175) (107,765) Total $ 93,559 $ 161,724 $ 113,494 $ 175,802 $ 368,794 $ 463,946 $ 390,737 $ 618,711

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 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 for the nine months ended September 30, 2020: Intangible assets Goodwill Intangible Intangible Total Total Balance as of December 31, 2019 $ 109,807 $ 14,630 $ 67,131 $ 81,761 $ 191,568 Impairment losses (StarStone International) (8,000) — (4,000) (4,000) (12,000) Amortization — (1,524) — (1,524) (1,524) Reclassification to assets held-for-sale (Atrium) (38,848) (13,106) (63,131) (76,237) (115,085) Balance as of September 30, 2020 $ 62,959 $ — $ — $ — $ 62,959
Schedule of Goodwill	The changes in the goodwill by segment were as follows for the nine months ended September 30, 2020: Non-life Atrium StarStone Total Balance as of December 31, 2019: $ 62,959 $ 38,848 $ 8,000 $ 109,807 Impairment losses (StarStone International) — — (8,000) (8,000) Reclassification to assets held-for-sale (Atrium) — (38,848) — (38,848) Balance as of September 30, 2020: Goodwill 62,959 — 8,000 70,959 Accumulated impairment losses — — (8,000) (8,000) $ 62,959 $ — $ — $ 62,959
Schedule of Indefinite-Lived Intangible Assets	The gross carrying value, accumulated amortization and net carrying value of intangible assets by segment and by type as of September 30, 2020 and December 31, 2019 was as follows: September 30, 2020 December 31, 2019 Gross Accumulated amortization Net Gross Accumulated amortization Net Atrium segment: Intangible assets with a definite life: Distribution channel $ — $ — $ — $ 20,000 $ (8,111) $ 11,889 Brand — — — 7,000 (4,259) 2,741 Intangible assets with an indefinite life: Lloyd’s syndicate capacity — — — 33,031 — 33,031 Management contract — — — 30,100 — 30,100 Total Atrium segment intangible assets $ — $ — $ — $ 90,131 $ (12,370) $ 77,761 StarStone segment: Intangible assets with an indefinite life: Lloyd’s syndicate capacity 4,000 (4,000) — 4,000 — 4,000 Total intangible assets $ 4,000 $ (4,000) $ — $ 94,131 $ (12,370) $ 81,761
Schedule of Finite-Lived Intangible Assets	The gross carrying value, accumulated amortization and net carrying value of intangible assets by segment and by type as of September 30, 2020 and December 31, 2019 was as follows: September 30, 2020 December 31, 2019 Gross Accumulated amortization Net Gross Accumulated amortization Net Atrium segment: Intangible assets with a definite life: Distribution channel $ — $ — $ — $ 20,000 $ (8,111) $ 11,889 Brand — — — 7,000 (4,259) 2,741 Intangible assets with an indefinite life: Lloyd’s syndicate capacity — — — 33,031 — 33,031 Management contract — — — 30,100 — 30,100 Total Atrium segment intangible assets $ — $ — $ — $ 90,131 $ (12,370) $ 77,761 StarStone segment: Intangible assets with an indefinite life: Lloyd’s syndicate capacity 4,000 (4,000) — 4,000 — 4,000 Total intangible assets $ 4,000 $ (4,000) $ — $ 94,131 $ (12,370) $ 81,761
Intangible Assets Amortization	Atrium As described above, the assets and liabilities related to the Atrium segment have been classified as held-for-sale as of September 30, 2020. The following table presents the amortization recorded on the intangible assets prior to the reclassification to held-for-sale: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Intangible asset amortization $ 508 $ 546 $ 1,524 $ 1,676

Debt Obligations and Credit F_2

Debt Obligations and Credit Facilities (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Amounts of Loans Payable Outstanding, and Accrued Interest	Our debt obligations were as follows: Facility Origination Date Term September 30, 2020 December 31, 2019 4.50% Senior Notes due 2022 March 10, 2017 5 years $ 349,155 $ 348,616 4.95% Senior Notes due 2029 May 28, 2019 10 years 493,940 493,600 Total Senior Notes 843,095 842,216 5.75% Junior Subordinated Notes due 2040 August 26, 2020 20 years 344,813 — EGL Revolving Credit Facility August 16, 2018 5 years 260,000 — 2018 EGL Term Loan Facility December 27, 2018 3 years — 348,991 Total debt obligations $ 1,447,908 $ 1,191,207
Interest Expense	The table below provides a summary of the total interest expense: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Interest expense on debt obligations $ 14,652 $ 14,623 $ 41,522 $ 38,157 Amortization of debt issuance costs 351 311 914 539 Funds withheld balances and other — 16 — 326 Total interest expense $ 15,003 $ 14,950 $ 42,436 $ 39,022

Noncontrolling Interests (Table

Noncontrolling Interests (Tables)	9 Months Ended
	Sep. 30, 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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Balance at beginning of period $ 366,533 $ 435,696 $ 438,791 $ 458,543 Dividends paid — — — (11,556) Net earnings (losses) attributable to RNCI 20,997 (190) (31,102) (5,651) Accumulated other comprehensive earnings attributable to RNCI 1,220 (97) 7,593 58 Foreign currency translation adjustments (588) — (753) — Change in redemption value of RNCI (11,431) (622) (38,059) (6,607) Cumulative effect of change in accounting principle attributable to RNCI (1) — — 261 — Balance at end of period $ 376,731 $ 434,787 $ 376,731 $ 434,787 (1) The Company adopted ASU 2016-13

Share Capital (Tables)

Share Capital (Tables)	9 Months Ended
	Sep. 30, 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 November 6, 2020: Dividend per: Preferred Share Series Date Declared Record Date Date Paid or Payable Preferred Share Depositary Share Total dividends paid in the nine months ended September 30, 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 7,000 Series E May 5, 2020 May 15, 2020 June 1, 2020 $ 437.50 $ 0.43750 1,925 Series D August 5, 2020 August 15, 2020 September 1, 2020 $ 437.50 $ 0.43750 7,000 Series E August 5, 2020 August 15, 2020 September 1, 2020 $ 437.50 $ 0.43750 1,925 Series D November 5, 2020 November 15, 2020 December 1, 2020 $ 437.50 $ 0.43750 — Series E November 5, 2020 November 15, 2020 December 1, 2020 $ 437.50 $ 0.43750 — $ 26,775

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 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 Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Numerator: Earnings (losses) attributable to Enstar ordinary shareholders: Net earnings from continuing operations (1) $ 612,636 $ 113,074 $ 896,267 $ 701,234 Net earnings from discontinued operations (2) 2,377 4,669 478 7,102 Net earnings attributable to Enstar ordinary shareholders: $ 615,013 $ 117,743 $ 896,745 $ 708,336 Denominator: Weighted-average ordinary shares outstanding — basic (3) 21,578,106 21,488,216 21,564,447 21,476,586 Effect of dilutive securities: Share-based compensation plans (4) 143,581 169,162 180,437 204,288 Warrants 57,042 63,119 54,743 60,625 Weighted-average ordinary shares outstanding — diluted 21,778,729 21,720,497 21,799,627 21,741,499 Earnings (loss) per ordinary share attributable to Enstar: Basic: Net earnings from continuing operations $ 28.39 $ 5.26 $ 41.56 $ 32.65 Net earnings from discontinued operations 0.11 0.22 0.02 0.33 Net earnings per ordinary share $ 28.50 $ 5.48 $ 41.58 $ 32.98 Diluted: Net earnings from continuing operations $ 28.13 $ 5.21 $ 41.12 $ 32.25 Net earnings from discontinued operations 0.11 0.21 0.02 0.33 Net earnings per ordinary share $ 28.24 $ 5.42 $ 41.14 $ 32.58 (1) Net earnings (loss) from continuing operations attributable to Enstar ordinary shareholders equals net earnings (loss) from continuing operations, plus net loss (earnings) from continuing operations attributable to noncontrolling interest, less dividends on preferred shares. (2) Net earnings (loss) from discontinued operations attributable to Enstar ordinary shareholders equals net earnings (loss) from discontinued operations, net of income taxes, plus net loss (earnings) from discontinued operations attributable to noncontrolling interest; refer to Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations" for a breakdown by period. (3) 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. (4) 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 and nine months ended September 30, 2020 because they were anti-dilutive.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Share-based compensation plans: Restricted shares and restricted share units $ 2,251 $ 1,778 $ 6,180 $ 4,910 Performance share units 5,698 5,678 10,886 18,133 Cash-settled stock appreciation rights 3,705 102 230 (109) Joint share ownership plan expense 1,146 — 3,151 — Other share-based compensation plans: Northshore incentive plan 209 1,029 656 3,061 StarStone incentive plan — — (223) — Deferred compensation and ordinary share plan for non-employee directors 139 116 1,098 992 Employee share purchase plan 110 102 318 309 Total share-based compensation $ 13,258 $ 8,805 $ 22,296 $ 27,296

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The RNCI on our balance sheet relating to these Trident co-investment transactions was as follows: September 30, 2020 December 31, 2019 Redeemable Noncontrolling Interest $ 361,026 $ 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: September 30, 2020 December 31, 2019 Short-term investments, AFS, at fair value $ — $ 1,431 Fixed maturities, trading, at fair value 219,435 269,131 Fixed maturities, AFS, at fair value 93,779 160,303 Equities, at fair value 94,353 121,794 Other investments, at fair value: Hedge funds 18,510 18,993 Fixed income funds 335,033 381,449 Private equity funds 32,050 34,858 CLO equities 33,358 32,560 CLO equity funds 140,458 87,509 Private Debt 27,079 16,312 Real estate fund 24,475 18,106 Total investments 1,018,530 1,142,446 Cash and cash equivalents 21,293 54,080 Other assets 6,327 10 Other liabilities 162 4,710 Net investment $ 1,045,988 $ 1,191,826 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net investment income $ 2,312 $ 2,257 $ 11,189 $ 5,009 Net realized and unrealized (losses) gains 35,925 (3,442) (36,862) 26,305 Total net (losses) earnings $ 38,237 $ (1,185) $ (25,673) $ 31,314 Our consolidated balance sheet included the following balances related to transactions with Hillhouse Capital and AnglePoint (as applicable): September 30, 2020 December 31, 2019 Investments in funds managed by AnglePoint, held by Enhanzed Re $ 653,040 $ 327,799 Our ownership of equity method investments 47.4 % 47.4 % Our share of Investments in funds managed by AnglePoint held by Enhanzed Re (through our ownership of equity method investments) $ 309,541 $ 155,377 Investment in other funds managed by Hillhouse Capital and AnglePoint: InRe Fund $ 1,843,532 $ 918,633 Other funds 306,214 232,968 $ 2,149,746 $ 1,151,601 Our investment in the common and preferred shares of Monument Re, which is included in equity method investments on our consolidated balance sheet, was as follows: September 30, 2020 December 31, 2019 Investment in Monument Re $ 161,994 $ 60,598 Our investment in the common shares of Clear Spring which is included in equity method investments on our consolidated balance sheet, was as follows: September 30, 2020 December 31, 2019 Investment in Clear Spring $ 10,944 $ 10,645 Our consolidated balance sheet included the following balances between us and Clear Spring: September 30, 2020 December 31, 2019 Balances under StarStone ceding quota share included, in assets or liabilities held-for-sale: Reinsurance balances recoverable $ 20,998 $ 22,812 Prepaid insurance premiums — 51 Ceded payable 3,551 3,616 Ceded acquisition costs — 21 Balances under assuming quota share: Losses and LAE 3,995 6,135 Unearned reinsurance premiums — 13 Funds held 7,468 8,611 Our consolidated statement of earnings included the following amounts between us and Clear Spring: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Transactions under StarStone ceding quota share, included in net earnings (loss) from discontinued operations: Ceded premium earned $ 60 $ (3,548) $ 61 $ (13,304) Ceded incurred losses and LAE (525) 1,063 (1,814) 8,051 Ceded acquisition costs (17) 243 (44) 305 Transactions under assuming quota share: Premium earned (15) 887 (15) 3,326 Net incurred losses and LAE 132 (576) 1,014 (2,013) Acquisition costs 4 (88) 11 (79) Total net earnings (loss) $ (361) $ (2,019) $ (787) $ (3,714) Our indirect investment in the shares of AmTrust, carried in equities on our consolidated balance sheet was as follows: September 30, 2020 December 31, 2019 Investment in AmTrust $ 245,361 $ 240,115 The following table presents the amounts included in net earnings related to our related party transactions with AmTrust: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net investment income $ — $ 1,900 $ 4,367 $ 5,550 Net realized and unrealized gains 45 — 3,854 — Total net earnings $ 45 $ 1,900 $ 8,221 $ 5,550 Our indirect investment in the shares of Citco, which is included in equity method investments on our consolidated balance sheet, was as follows: September 30, 2020 December 31, 2019 Investment in Citco $ 51,946 $ 51,742 Our investment in the common shares of Enhanzed Re, which is included in equity method investments on our consolidated balance sheet, was as follows: September 30, 2020 December 31, 2019 Investment in Enhanzed Re $ 271,678 $ 182,856 Our consolidated balance sheet included the following balances between us and Enhanzed Re: September 30, 2020 December 31, 2019 Balances under ceding quota share: Insurance balances payables $ 1,759 $ 1,443 Reinsurance balances recoverable 53,762 59,601 Funds held 47,808 50,089 Other assets 498 1,033 Our consolidated statement of earnings included the following amounts between us and Enhanzed Re: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Amounts under ceding quota share: Net incurred losses and LAE $ (1) $ — $ (14) $ — Acquisition costs (46) — (23) — Net investment income (819) — (819) — Net realized and unrealized gains (679) — (679) — Other income 3,113 — — — Fees and commission income 161 150 393 402 Total Net earnings 1,729 150 (1,142) 402 Change in realized gain (losses) on available-for-sale investments (2,239) — (2,239) —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 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 September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Lease cost: Operating lease cost $ 3,036 $ 4,010 $ 9,560 $ 10,696 Short-term lease cost (1) 63 — 182 — Total lease cost 3,099 4,010 9,742 10,696 Sub-lease income (2) (139) (183) (415) (451) Total net lease cost $ 2,960 $ 3,827 $ 9,327 $ 10,245 Other information: Operating cash paid for amounts included in the measurement of lease liabilities $ 2,856 $ 2,945 $ 10,184 $ 9,138 Non-cash activity: right-of-use assets relating to leases (179) 1,353 84 53,581 Weighted-average remaining lease term 6.1 years 6.4 years Weighted-average discount rate 6.4 % 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.
Assets and Liabilities, Lessee	The table below provides a summary of the operating leases recorded on our consolidated balance sheets: Balance sheet classification September 30, 2020 December 31, 2019 Right-of-use assets (1) (2) Other assets $ 33,224 $ 46,747 Current lease liabilities (2) Other liabilities 7,955 11,403 Non-current lease liabilities (2) Other liabilities 28,126 34,785 (1) Following our decision to put the StarStone International operations into orderly run-off effective June 10, 2020, we recorded total impairment charges of $3.5 million on the right-of-use assets relating to certain StarStone International operating leases as of September 30, 2020. (2) The right-of-use assets and the total lease liability balances exclude balances of $1.5 million and $1.0 million respectively, related to Atrium which have been reclassified to held-for-sale balances on our consolidated balance sheet as of September 30, 2020.
Lessee, Operating Lease, Liability, Maturity	The table below provides a summary of the contractual maturities of our operating lease liabilities: September 30, 2020 2020 $ 2,938 2021 9,347 2022 7,829 2023 7,032 2024 5,328 2025 and beyond 12,579 Total lease payments (1) 45,053 Less: Imputed interest (8,972) Present value of lease liabilities $ 36,081

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2020 Non-life Atrium StarStone Other Total Gross premiums written $ 3,535 $ 49,083 $ 58,566 $ 293 $ 111,477 Net premiums written $ 3,424 $ 46,503 $ 43,338 $ 294 $ 93,559 Net premiums earned $ 17,476 $ 42,426 $ 96,116 $ 5,706 $ 161,724 Net incurred losses and LAE (34,258) (21,995) (48,390) (5,043) (109,686) Acquisition costs (2,730) (14,242) (20,608) (128) (37,708) Operating expenses (50,345) (3,008) (20,440) — (73,793) Underwriting income (loss) (69,857) 3,181 6,678 535 (59,463) Net investment income (loss) 66,918 1,778 6,298 (2,864) 72,130 Net realized and unrealized gains 486,671 1,533 11,801 — 500,005 Fees and commission income 3,637 7,150 — — 10,787 Other income 48,023 72 99 210 48,404 Corporate expenses (22,494) (6,084) (3,137) (10,320) (42,035) Interest income (expense) (16,705) — (510) 2,212 (15,003) Net foreign exchange gains (losses) (9,663) 2,275 (761) (7) (8,156) EARNINGS (LOSS) BEFORE INCOME TAXES 486,530 9,905 20,468 (10,234) 506,669 Income tax expense (9,271) (2,520) (733) (1,391) (13,915) Earnings from equity method investments 149,065 — — — 149,065 NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 626,324 7,385 19,735 (11,625) 641,819 NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES — — 4,031 — 4,031 NET EARNINGS (LOSS) 626,324 7,385 23,766 (11,625) 645,850 Net earnings attributable to noncontrolling interest (2,519) (2,996) (16,397) — (21,912) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR 623,805 4,389 7,369 (11,625) 623,938 Dividends on preferred shares — — — (8,925) (8,925) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 623,805 $ 4,389 $ 7,369 $ (20,550) $ 615,013 Underwriting ratios: Loss ratio 51.8 % 50.3 % Acquisition expense ratio 33.6 % 21.4 % Operating expense ratio 7.1 % 21.4 % Combined ratio 92.5 % 93.1 % Three Months Ended September 30, 2019 Non-life Atrium StarStone Other Total Gross premiums written $ 301 $ 48,746 $ 110,586 $ (2,498) $ 157,135 Net premiums written $ (3,808) $ 43,785 $ 76,020 $ (2,503) $ 113,494 Net premiums earned $ 16,837 $ 42,913 $ 111,749 $ 4,303 $ 175,802 Net incurred losses and LAE (30,583) (28,400) (100,628) (3,647) (163,258) Acquisition costs 4,634 (14,466) (23,301) (177) (33,310) Operating expenses (51,395) (3,742) (14,525) — (69,662) Underwriting income (loss) (60,507) (3,695) (26,705) 479 (90,428) Net investment income (loss) 73,752 1,736 8,161 (2,147) 81,502 Net realized and unrealized gains 138,174 582 6,034 270 145,060 Fees and commission income (expense) 4,196 2,391 (150) — 6,437 Other income (expense) (285) 35 72 1,000 822 Corporate expenses (11,983) (2,896) — (12,824) (27,703) Interest income (expense) (17,964) — — 3,014 (14,950) Net foreign exchange gains (losses) 13,056 (924) 1,509 24 13,665 EARNINGS (LOSS) BEFORE INCOME TAXES 138,439 (2,771) (11,079) (10,184) 114,405 Income tax benefit (expense) (13,382) (222) 139 — (13,465) Earnings from equity method investments 17,703 — — — 17,703 NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 142,760 (2,993) (10,940) (10,184) 118,643 NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES — — 7,916 — 7,916 NET EARNINGS (LOSS) 142,760 (2,993) (3,024) (10,184) 126,559 Net (earnings) loss attributable to noncontrolling interest (1,439) 1,228 320 — 109 NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR 141,321 (1,765) (2,704) (10,184) 126,668 Dividend on preferred shares — — — (8,925) (8,925) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 141,321 $ (1,765) $ (2,704) $ (19,109) $ 117,743 Underwriting ratios: Loss ratio 66.2 % 90.0 % Acquisition expense ratio 33.7 % 20.9 % Operating expense ratio 8.7 % 13.0 % Combined ratio 108.6 % 123.9 % Nine Months Ended September 30, 2020 Non-Life Atrium StarStone Other Total Gross premiums written $ 1,707 $ 155,551 $ 300,135 $ 3,237 $ 460,630 Net premiums written $ 2,397 $ 136,093 $ 227,066 $ 3,238 $ 368,794 Net premiums earned $ 44,023 $ 128,183 $ 276,566 $ 15,174 $ 463,946 Net incurred losses and LAE (63,698) (66,003) (197,259) (12,718) (339,678) Acquisition costs (13,226) (43,235) (76,026) (331) (132,818) Operating expenses (147,117) (8,757) (66,385) — (222,259) Underwriting income (loss) (180,018) 10,188 (63,104) 2,125 (230,809) Net investment income (loss) 223,425 4,382 21,625 (8,145) 241,287 Net realized and unrealized gains (losses) 838,483 3,392 (3,323) — 838,552 Fees and commission income 12,588 15,737 — — 28,325 Other income (expense) 68,087 105 216 (647) 67,761 Corporate expenses (48,014) (14,494) (39,153) (35,166) (136,827) Interest income (expense) (48,785) — (1,611) 7,960 (42,436) Net foreign exchange gains (losses) 385 1,115 (5,509) 2,634 (1,375) EARNINGS (LOSS) BEFORE INCOME TAXES 866,151 20,425 (90,859) (31,239) 764,478 Income tax expense (18,276) (3,303) (2,325) (1,391) (25,295) Earnings from equity method investments 152,725 — — — 152,725 NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 1,000,600 17,122 (93,184) (32,630) 891,908 NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES — — 810 — 810 NET EARNINGS (LOSS) 1,000,600 17,122 (92,374) (32,630) 892,718 Net (earnings) loss attributable to noncontrolling interest 504 (7,024) 37,322 — 30,802 NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR 1,001,104 10,098 (55,052) (32,630) 923,520 Dividends on preferred shares — — — (26,775) (26,775) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 1,001,104 $ 10,098 $ (55,052) $ (59,405) $ 896,745 Underwriting ratios: Loss ratio 51.5 % 71.3 % Acquisition expense ratio 33.7 % 27.5 % Operating expense ratio 6.9 % 24.0 % Combined ratio 92.1 % 122.8 % Nine Months Ended September 30, 2019 Non-Life Atrium StarStone Other Total Gross premiums written $ (24,785) $ 146,519 $ 363,352 $ (1,174) $ 483,912 Net premiums written $ (26,395) $ 127,246 $ 291,083 $ (1,197) $ 390,737 Net premiums earned $ 141,981 $ 119,865 $ 339,993 $ 16,872 $ 618,711 Net incurred losses and LAE (135,517) (58,662) (358,864) (13,068) (566,111) Acquisition costs (40,033) (41,023) (80,582) (554) (162,192) Operating expenses (139,595) (9,968) (53,217) — (202,780) Underwriting income (loss) (173,164) 10,212 (152,670) 3,250 (312,372) Net investment income (loss) 206,337 5,500 25,865 (6,278) 231,424 Net realized and unrealized gains 815,902 5,464 31,274 5,849 858,489 Fees and commission income (expense) 13,673 5,773 (515) — 18,931 Other income (expense) 15,136 106 445 (319) 15,368 Corporate expenses (47,287) (10,186) — (36,051) (93,524) Interest income (expense) (45,699) — (475) 7,152 (39,022) Net foreign exchange gains (losses) 20,426 (1) (326) (2) 20,097 EARNINGS (LOSS) BEFORE INCOME TAXES 805,324 16,868 (96,402) (26,399) 699,391 Income tax benefit (expense) (23,501) (1,930) 251 (85) (25,265) Earnings (loss) from equity method investments 44,406 — (218) — 44,188 NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 826,229 14,938 (96,369) (26,484) 718,314 NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES — — 12,041 — 12,041 NET EARNINGS (LOSS) 826,229 14,938 (84,328) (26,484) 730,355 Net (earnings) loss attributable to noncontrolling interest (6,351) (6,127) 17,448 — 4,970 NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR 819,878 8,811 (66,880) (26,484) 735,325 Dividends on preferred shares — — — (26,989) (26,989) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS $ 819,878 $ 8,811 $ (66,880) $ (53,473) $ 708,336 Underwriting ratios: Loss ratio 48.9 % 105.6 % Acquisition expense ratio 34.2 % 23.7 % Operating expense ratio 8.4 % 15.6 % Combined ratio 91.5 % 144.9 %
Summary of Company's 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: September 30, 2020 December 31, 2019 Assets by Segment: Non-life Run-off (1) $ 17,961,439 $ 15,775,407 Atrium (2) 638,529 580,405 StarStone (3) 4,021,240 3,985,138 Other (850,620) (514,851) Total assets $ 21,770,588 $ 19,826,099 (1) The total assets within the Non-life Run-off segment include assets of $12.4 million related to Arden's operations that have been included within Northshore's held-for-sale assets in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations." (2) The total assets within the Atrium segment are all included within Northshore's held-for-sale assets in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations." (3) The total assets within the StarStone segment include assets of $1.5 billion related to StarStone U.S. which are disclosed as held-for-sale assets in Note 4 - "Divestitures, Held-for-Sale Businesses and Discontinued Operations."

Significant Accounting Polici_3

Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2020	Jun. 30, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounting standards update	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201613Member
Decrease to retained earnings		$ 2,887,892	$ 3,816,548
Reinsurance recoverable, allowance for credit loss		147,639	135,117	$ 143,653
Allowance for credit losses		0	$ 912	3,673
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		(195)		0
Allowance for credit losses		$ 3,059		$ 0

Significant New Business (Detai

Significant New Business (Details) $ in Thousands, $ in Millions	Oct. 01, 2020	Aug. 06, 2020USD ($)	Jul. 01, 2020USD ($)	Jul. 01, 2020AUD ($)	Jun. 01, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Guarantor Obligations [Line Items]
Assumed business							$ 280,497	$ 445,000	$ 1,705,970	$ 1,110,881
Fair value adjustments - acquired companies							(147,839)		(147,839)			$ (167,511)
Deferred charge asset							$ 248,200	$ 167,268	248,200	$ 167,268	$ 258,516	$ 272,462	$ 99,094	$ 86,585
Hannover Re
Guarantor Obligations [Line Items]
Assumed business		$ 209,700
Reinsurance premium consideration		182,500
Fair value adjustments - acquired companies		$ 27,200
Munich Re
Guarantor Obligations [Line Items]
Net loss reserves			$ 98,000	$ 142.2
AXA Group
Guarantor Obligations [Line Items]
Assumed business					$ 179,700
Reinsurance premium consideration					24,500				$ 204,200
AXA Group | Scenario, Forecast
Guarantor Obligations [Line Items]
Percentage ceded	10.00%
Aspen
Guarantor Obligations [Line Items]
Assumed business					781,600
Reinsurance premium consideration					770,000
Deferred charge asset					11,700
Additional assumed business					250,000
Pacific Valley Insurance Company
Guarantor Obligations [Line Items]
Reinsurance premium consideration						$ 465,000
Retrocession coverage						$ 816,000
Minimum | Aspen
Guarantor Obligations [Line Items]
Assumed business					3,800,000
Additional assumed business					$ 4,800,000

Divestitures, Held-For-Sale B_3

Divestitures, Held-For-Sale Businesses and Discontinued Operations - Additional Information (Details) $ in Thousands, € in Millions	Oct. 14, 2020USD ($)entity	Oct. 14, 2020EUR (€)entity	Oct. 02, 2020USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)	Mar. 31, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership %					47.40%		47.40%		47.40%
Assumed business					$ 280,497	$ 445,000	$ 1,705,970	$ 1,110,881
StarStone International | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of entities | entity	2	2
Proceeds from sale of renewal rights			$ 500
North Bay
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage in noncontrolling interest by parent					59.00%		59.00%
North Bay | Trident
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest owned by an entity (percent)					39.30%		39.30%
North Bay | Dowling
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest owned by an entity (percent)					1.70%		1.70%
SSHL
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage in noncontrolling interest by parent					59.00%		59.00%
SSHL | North Bay
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage in noncontrolling interest by parent					100.00%		100.00%
SSHL | Trident
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest owned by an entity (percent)					39.30%		39.30%
SSHL | Dowling
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest owned by an entity (percent)					1.70%		1.70%
Northshore | North Bay
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage in noncontrolling interest by parent					92.10%		92.10%
StarStone US
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage in noncontrolling interest by parent					59.00%		59.00%
Northshore | Disposal group, held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restricted investments					$ 117,600		$ 117,600
Unrealized gain (losses)							(300)
StarStone US | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restricted investments					$ 146,500		146,500		$ 131,000
Unrealized gain (losses)							$ 16,100		$ (1,000)
Vander Haeghen & CO SA | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale	$ 4,500	€ 3.8
Scenario, Forecast | Core Specialty
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership %										26.10%
Scenario, Forecast | Northshore | Trident
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest owned by an entity (percent)										80.00%
Scenario, Forecast | Northshore | Dowling
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest owned by an entity (percent)										1.60%
Scenario, Forecast | Northshore | Core Specialty
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest owned by an entity (percent)										11.00%
Scenario, Forecast | Core Specialty | Dowling
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest owned by an entity (percent)										0.50%
Scenario, Forecast | StarStone US
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reinsurance premium, additional consideration to be received				$ 16,000
Assumed business				130,000
Scenario, Forecast | StarStone US | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Premium to tangible book value				30,000
Consideration receivable				235,000
Scenario, Forecast | Vander Haeghen & CO SA | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale				$ 3,600

Divestitures, Held-For-Sale B_4

Divestitures, Held-For-Sale Businesses and Discontinued Operations - Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
ASSETS
TOTAL ASSETS HELD-FOR-SALE	$ 2,156,488		$ 2,156,488		$ 1,474,770
LIABILITIES
TOTAL LIABILITIES HELD-FOR-SALE	1,653,343		1,653,343		1,208,531
EXPENSES
NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	4,031	$ 7,916	810	$ 12,041
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Operating activities			114,024	210,666
Investing activities			(134,759)	(5,332)
Net cash flows from discontinued operations			(20,735)	205,334
Northshore | Disposal group, held-for-sale
ASSETS
Equities, at fair value	18,120		18,120
Other investments, at fair value	87,795		87,795
Total investments	271,344		271,344
Cash and cash equivalents	61,221		61,221
Restricted cash and cash equivalents	10,152		10,152
Premiums receivable	59,484		59,484
Deferred tax assets	97		97
Reinsurance balances recoverable on paid and unpaid losses	30,673		30,673
Funds held by reinsured companies	30,092		30,092
Deferred acquisition costs	24,522		24,522
Goodwill and intangible assets	115,085		115,085
Other assets	48,308		48,308
TOTAL ASSETS HELD-FOR-SALE	650,978		650,978
LIABILITIES
Losses and loss adjustment expenses	248,532		248,532
Unearned premiums	91,608		91,608
Insurance and reinsurance balances payable	10,916		10,916
Deferred tax liabilities	14,010		14,010
Other liabilities	66,020		66,020
TOTAL LIABILITIES HELD-FOR-SALE	431,086		431,086
NET ASSETS HELD-FOR-SALE	219,892		219,892
Northshore | Disposal group, held-for-sale | Short-term investments
ASSETS
Available-for-sale, at fair value	1,852		1,852
Northshore | Disposal group, held-for-sale | Fixed maturity investments
ASSETS
Trading, at fair value	154,325		154,325
Available-for-sale, at fair value	9,252		9,252
StarStone US | Discontinued Operations, Held-for-sale
ASSETS
Trading, at fair value	140,124		140,124		202,994
Available-for-sale, at fair value	525,842		525,842		375,337
Equities, at fair value	5,494		5,494		3,000
Other investments, at fair value	6,864		6,864		6,389
Total investments	678,324		678,324		587,720
Cash and cash equivalents	54,303		54,303		78,613
Restricted cash and cash equivalents	9,390		9,390		5,815
Premiums receivable	105,339		105,339		99,367
Deferred tax assets	14,890		14,890		15,191
Reinsurance balances recoverable on paid and unpaid losses	477,739		477,739		530,604
Funds held by reinsured companies	29,678		29,678		35,861
Deferred acquisition costs	32,071		32,071		36,992
Goodwill and intangible assets	24,900		24,900		24,900
Other assets	78,876		78,876		59,707
TOTAL ASSETS HELD-FOR-SALE	1,505,510		1,505,510		1,474,770
LIABILITIES
Losses and loss adjustment expenses	830,456		830,456		836,761
Unearned premiums	217,375		217,375		218,166
Insurance and reinsurance balances payable	49,822		49,822		22,453
Other liabilities	124,604		124,604		131,151
TOTAL LIABILITIES HELD-FOR-SALE	1,222,257		1,222,257		1,208,531
NET ASSETS HELD-FOR-SALE	283,253		283,253		$ 266,239
INCOME
Net premiums earned	75,414	94,523	241,363	263,464
Fees and commission income	0	150	0	515
Net investment income	3,649	3,970	11,063	11,831
Net realized and unrealized gains	1,910	3,125	2,757	20,198
Other income	55	4	80	10
Total income	81,028	101,772	255,263	296,018
EXPENSES
Net incurred losses and loss adjustment expenses	44,939	59,159	157,648	185,048
Acquisition costs	14,776	16,972	47,570	48,733
General and administrative expenses	16,675	16,558	47,404	47,213
Interest expense	535	0	1,715	1,355
Net foreign exchange (gains) losses	(3)	34	(5)	29
Total expenses	76,922	92,723	254,332	282,378
EARNINGS (LOSS) BEFORE INCOME TAXES	4,106	9,049	931	13,640
Income tax benefit (expense)	(75)	(1,133)	(121)	(1,599)
NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	4,031	7,916	810	12,041
Net loss (earnings) from discontinued operations attributable to noncontrolling interest	(1,654)	(3,247)	(332)	(4,939)
NET EARNINGS (LOSS) FROM DISCONTINUED OPERATIONS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	2,377	4,669	478	7,102
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Operating activities			114,024	210,666
Investing activities			(134,759)	(5,332)
Net cash flows from discontinued operations			(20,735)	205,334
Discontinued Operation, Continuing Involvement [Abstract]
Total income	9,072	8,082	1,709	3,373
Total expenses (income)	(16,682)	41,884	(1,783)	(4,582)
Net earnings (loss)	$ 25,754	$ (33,802)	$ 3,492	$ 7,955

Investments - Asset Types - Fix

Investments - Asset Types - Fixed Maturity Investments (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	$ 3,161,647,000	$ 1,666,387,000
Total fair value	9,222,623,000	9,034,557,000
U.S. government and agency
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	550,589,000	381,244,000
Total fair value	789,630,000	696,077,000
U.K. government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	42,974,000	15,349,000
Total fair value	114,777,000	161,772,000
Other government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	136,130,000	85,147,000
Total fair value	490,447,000	702,856,000
Corporate
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	1,679,448,000	880,472,000
Total fair value	5,679,909,000	5,448,270,000
Municipal
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	30,806,000	3,780,000
Total fair value	161,839,000	140,687,000
Residential mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	293,811,000	99,188,000
Total fair value	529,239,000	400,914,000
Commercial mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	228,207,000	49,046,000
Total fair value	843,119,000	813,746,000
Asset-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, fair value	199,682,000	152,161,000
Total fair value	613,663,000	670,235,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	458,800,000	333,300,000
Senior Secured Debt Securities
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	0	31,400,000
Short-term investments, AFS, at fair value
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	7,133,000	51,490,000
Debt securities, fair value	278,175,000	128,335,000
Short-term investments, AFS, at fair value | U.S. government and agency
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	3,399,000	0
Debt securities, fair value	252,449,000	111,583,000
Short-term investments, AFS, at fair value | U.K. government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	0	24,411,000
Debt securities, fair value	0	1,069,000
Short-term investments, AFS, at fair value | Other government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	2,872,000	21,958,000
Debt securities, fair value	0	387,000
Short-term investments, AFS, at fair value | Corporate
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	862,000	5,121,000
Debt securities, fair value	25,726,000	13,915,000
Short-term investments, AFS, at fair value | Municipal
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	0	0
Debt securities, fair value	0	1,381,000
Short-term investments, AFS, at fair value | 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, AFS, at fair value | 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, AFS, at fair value | 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	4,999,642,000	6,143,335,000
Debt securities, fair value	2,883,472,000	1,538,052,000
Fixed maturity investments | U.S. government and agency
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	148,378,000	208,296,000
Debt securities, fair value	298,140,000	269,661,000
Fixed maturity investments | U.K. government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	71,803,000	122,012,000
Debt securities, fair value	42,974,000	14,280,000
Fixed maturity investments | Other government
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	327,406,000	575,017,000
Debt securities, fair value	136,130,000	84,760,000
Fixed maturity investments | Corporate
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	3,474,857,000	3,959,288,000
Debt securities, fair value	1,653,722,000	866,557,000
Fixed maturity investments | Municipal
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	79,296,000	87,451,000
Debt securities, fair value	30,806,000	2,399,000
Fixed maturity investments | Residential mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	157,773,000	215,521,000
Debt securities, fair value	293,811,000	99,188,000
Fixed maturity investments | Commercial mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	382,735,000	534,357,000
Debt securities, fair value	228,207,000	49,046,000
Fixed maturity investments | Asset-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	357,394,000	441,393,000
Debt securities, fair value	199,682,000	152,161,000
Funds held - directly managed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	1,054,201,000	1,173,345,000
Funds held - directly managed | U.S. government and agency
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	87,264,000	106,537,000
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	24,039,000	20,734,000
Funds held - directly managed | Corporate
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	524,742,000	603,389,000
Funds held - directly managed | Municipal
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	51,737,000	49,456,000
Funds held - directly managed | Residential mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	77,655,000	86,205,000
Funds held - directly managed | Commercial mortgage-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	232,177,000	230,343,000
Funds held - directly managed | Asset-backed
Debt and Equity Securities, FV-NI [Line Items]
Debt securities, trading	$ 56,587,000	$ 76,681,000

Investments - Contractual Matur

Investments - Contractual Maturities (Details) - Short-Term Investments and Fixed Maturities $ in Thousands	Sep. 30, 2020USD ($)
Amortized Cost
One year or less	$ 556,125
More than one year through two years	589,231
More than two years through five years	2,080,715
More than five years through ten years	2,010,769
More than ten years	1,595,695
Trading securities, amortized cost	8,807,046
Fair Value
One year or less	559,086
More than one year through two years	598,559
More than two years through five years	2,163,967
More than five years through ten years	2,149,170
More than ten years	1,765,820
Trading securities, debt	$ 9,222,623
% of Total Fair Value
One year or less	6.10%
More than one year through two years	6.50%
More than two years through five years	23.50%
More than five years through ten years	23.30%
More than ten years	19.10%
Trading securities, percentage of fair value	100.00%
Residential mortgage-backed
Amortized Cost
Securities without single maturity date	$ 521,383
Fair Value
Securities without single maturity date	$ 529,239
% of Total Fair Value
Securities without single maturity date	5.70%
Commercial mortgage-backed
Amortized Cost
Securities without single maturity date	$ 821,995
Fair Value
Securities without single maturity date	$ 843,119
% of Total Fair Value
Securities without single maturity date	9.10%
Asset-backed
Amortized Cost
Securities without single maturity date	$ 631,133
Fair Value
Securities without single maturity date	$ 613,663
% of Total Fair Value
Securities without single maturity date	6.70%

Investments - Credit Ratings (D

Investments - Credit Ratings (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 8,807,046
Fair Value	9,222,623
Non- Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 309,562
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	3.30%
AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 2,589,004
AAA Rated | Marketable Securities | Credit Rating Concentration Risk | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	28.10%
AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,131,405
AA Rated | Marketable Securities | Credit Rating Concentration Risk | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	12.30%
A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 3,033,180
A Rated | Marketable Securities | Credit Rating Concentration Risk | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	32.90%
BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 2,141,856
BBB Rated | Marketable Securities | Credit Rating Concentration Risk | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	23.20%
Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 17,616
Not Rated | Marketable Securities | Credit Rating Concentration Risk
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	0.20%
U.S. government and agency
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 769,544
Fair Value	789,630
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	8.60%
U.S. government and agency | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 789,630
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	111,169
Fair Value	114,777
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	1.20%
U.K. government | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 0
U.K. government | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	102,624
U.K. government | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	8,739
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	3,414
Other government
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	466,575
Fair Value	490,447
Other government | Non- Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 9,458
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	5.30%
Other government | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 242,097
Other government | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	150,005
Other government | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	43,003
Other government | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	45,884
Other government | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
Corporate
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	5,339,160
Fair Value	5,679,909
Corporate | Non- Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 267,765
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	61.60%
Corporate | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 206,345
Corporate | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	583,595
Corporate | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	2,704,861
Corporate | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	1,912,857
Corporate | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	4,486
Municipal
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	146,087
Fair Value	161,839
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	$ 7,137
Municipal | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	83,519
Municipal | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	51,538
Municipal | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	19,645
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	521,383
Fair Value	529,239
Residential mortgage-backed | Non- Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 5,251
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	5.70%
Residential mortgage-backed | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 517,915
Residential mortgage-backed | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
Residential mortgage-backed | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	2,154
Residential mortgage-backed | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	1,612
Residential mortgage-backed | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	2,307
Commercial mortgage-backed
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	821,995
Fair Value	843,119
Commercial mortgage-backed | Non- Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 5,308
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	9.10%
Commercial mortgage-backed | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 576,643
Commercial mortgage-backed | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	111,720
Commercial mortgage-backed | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	77,391
Commercial mortgage-backed | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	64,898
Commercial mortgage-backed | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	7,159
Asset-backed
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	631,133
Fair Value	613,663
Asset-backed | Non- Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 21,780
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	6.70%
Asset-backed | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 249,237
Asset-backed | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	99,942
Asset-backed | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	145,494
Asset-backed | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	96,960
Asset-backed | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 250

Investments - Available-for-sal

Investments - Available-for-sale Portfolios - Unrealized Gains and Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 3,115,580		$ 1,666,126
Gross Unrealized Gains	58,158		5,608
Non-Credit Related Losses	(11,179)		(5,347)
Allowance for credit losses	(912)	$ (3,673)	0
Debt securities, fair value	3,161,647		1,666,387
U.S. government and agency
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	546,799		381,488
Gross Unrealized Gains	4,071		78
Non-Credit Related Losses	(281)		(322)
Allowance for credit losses	0
Debt securities, fair value	550,589		381,244
U.K. government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	42,025		15,067
Gross Unrealized Gains	995		282
Non-Credit Related Losses	(46)		0
Allowance for credit losses	0
Debt securities, fair value	42,974		15,349
Other government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	131,861		84,116
Gross Unrealized Gains	4,279		1,119
Non-Credit Related Losses	(10)		(88)
Allowance for credit losses	0	0	0
Debt securities, fair value	136,130		85,147
Corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,646,014		880,667
Gross Unrealized Gains	40,601		3,739
Non-Credit Related Losses	(6,383)		(3,934)
Allowance for credit losses	(784)	(3,090)	0
Debt securities, fair value	1,679,448		880,472
Municipal
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29,810		3,770
Gross Unrealized Gains	1,012		12
Non-Credit Related Losses	(16)		(2)
Allowance for credit losses	0
Debt securities, fair value	30,806		3,780
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	292,153		99,646
Gross Unrealized Gains	2,211		221
Non-Credit Related Losses	(551)		(679)
Allowance for credit losses	(2)	0	0
Debt securities, fair value	293,811		99,188
Commercial mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	226,292		49,219
Gross Unrealized Gains	4,347		30
Non-Credit Related Losses	(2,351)		(203)
Allowance for credit losses	(81)	(494)	0
Debt securities, fair value	228,207		49,046
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	200,626		152,153
Gross Unrealized Gains	642		127
Non-Credit Related Losses	(1,541)		(119)
Allowance for credit losses	(45)	$ (89)	0
Debt securities, fair value	$ 199,682		$ 152,161

Investments - Gross Unrealized

Investments - Gross Unrealized Losses (Details) $ in Thousands	Sep. 30, 2020USD ($)Security	Dec. 31, 2019USD ($)Security
Fair Value
12 Months or Greater	$ 0	$ 3,962
Less Than 12 Months	1,025,103	760,469
Total	1,025,103	764,431
Gross Unrealized Losses
12 Months or Greater	0	(329)
Less Than 12 Months	(9,359)	(5,018)
Total	$ (9,359)	$ (5,347)
Number of securities classified as available-for-sale in an unrealized loss position | Security	721	479
Number of securities classified as available-for-sale in an unrealized loss position for twelve months or longer | Security	0	12
U.S. government and agency
Fair Value
12 Months or Greater	$ 0	$ 0
Less Than 12 Months	170,590	193,574
Total	170,590	193,574
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(281)	(322)
Total	(281)	(322)
U.K. government
Fair Value
12 Months or Greater	0
Less Than 12 Months	2,911
Total	2,911
Gross Unrealized Losses
12 Months or Greater	0
Less Than 12 Months	(46)
Total	(46)
Other government
Fair Value
12 Months or Greater	0	1,080
Less Than 12 Months	7,392	37,796
Total	7,392	38,876
Gross Unrealized Losses
12 Months or Greater	0	(23)
Less Than 12 Months	(10)	(65)
Total	(10)	(88)
Corporate
Fair Value
12 Months or Greater	0	2,754
Less Than 12 Months	498,974	338,965
Total	498,974	341,719
Gross Unrealized Losses
12 Months or Greater	0	(306)
Less Than 12 Months	(5,585)	(3,628)
Total	(5,585)	(3,934)
Municipal
Fair Value
12 Months or Greater	0	128
Less Than 12 Months	3,551	761
Total	3,551	889
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(16)	(2)
Total	(16)	(2)
Residential mortgage-backed
Fair Value
12 Months or Greater	0	0
Less Than 12 Months	136,602	52,005
Total	136,602	52,005
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(383)	(679)
Total	(383)	(679)
Commercial mortgage-backed
Fair Value
12 Months or Greater	0	0
Less Than 12 Months	69,226	35,777
Total	69,226	35,777
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(1,652)	(203)
Total	(1,652)	(203)
Asset-backed
Fair Value
12 Months or Greater	0	0
Less Than 12 Months	135,857	101,591
Total	135,857	101,591
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(1,386)	(119)
Total	$ (1,386)	$ (119)

Investments - Allowance for Cre

Investments - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Accounting standards update		us-gaap:AccountingStandardsUpdate201613Member		us-gaap:AccountingStandardsUpdate201613Member
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	$ (3,673)	$ 0	$ 0
Allowances for credit losses on securities for which credit losses were not previously recorded	(164)		(11,067)
Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets	0		0
Reductions for securities sold during the period	341		2,130
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	0		0
(Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period	2,584		11,084
Allowance for credit losses, end of period	(912)		(912)	$ 0
Other government
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	0	0	0
Allowances for credit losses on securities for which credit losses were not previously recorded	0		0
Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets	0		0
Reductions for securities sold during the period	0		22
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	0		0
(Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period	0		0
Allowance for credit losses, end of period	0		0	0
Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	(3,090)	0	0
Allowances for credit losses on securities for which credit losses were not previously recorded	(39)		(10,359)
Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets	0		0
Reductions for securities sold during the period	341		2,108
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	0		0
(Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period	2,004		10,454
Allowance for credit losses, end of period	(784)		(784)	0
Residential mortgage-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	0	0	0
Allowances for credit losses on securities for which credit losses were not previously recorded	(2)		(2)
Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets	0		0
Reductions for securities sold during the period	0		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	0		0
(Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period	0		0
Allowance for credit losses, end of period	(2)		(2)	0
Commercial mortgage-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	(494)	0	0
Allowances for credit losses on securities for which credit losses were not previously recorded	(78)		(572)
Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets	0		0
Reductions for securities sold during the period	0		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	0		0
(Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period	491		541
Allowance for credit losses, end of period	(81)		(81)	0
Asset-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	(89)	0	0
Allowances for credit losses on securities for which credit losses were not previously recorded	(45)		(134)
Additions to the allowance for credit losses arising from purchases of securities accounted for as PCD assets	0		0
Reductions for securities sold during the period	0		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	0		0
(Increase) decrease to the allowance for credit losses on securities that had an allowance recorded in the previous period	89		89
Allowance for credit losses, end of period	(45)		(45)	0
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	0	(3,059)	(3,059)
Allowance for credit losses, end 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	0	(22)	(22)
Allowance for credit losses, end 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	0	(2,987)	(2,987)
Allowance for credit losses, end of period				(2,987)
Cumulative effect of change in accounting principle | Residential mortgage-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	0	0	0
Allowance for credit losses, end of period				0
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	0	(50)	(50)
Allowance for credit losses, end of period				(50)
Cumulative effect of change in accounting principle | Asset-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	$ 0	$ 0	$ 0
Allowance for credit losses, end of period				$ 0

Investments - Other Than Tempor

Investments - Other Than Temporary Impairment (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Other than temporary impairment losses, available-for-sale securities	$ 0	$ 0
Available-for-sale Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Credit losses			$ 0

Investments - Equities - Equity

Investments - Equities - Equity Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Equities, at fair value	$ 653,159	$ 726,721
Publicly traded equity investments in common and preferred stocks
Debt and Equity Securities, FV-NI [Line Items]
Equities, at fair value	303,932	327,875
Exchange-traded funds
Debt and Equity Securities, FV-NI [Line Items]
Equities, at fair value	78,182	133,047
Privately held equity investments in common and preferred stocks
Debt and Equity Securities, FV-NI [Line Items]
Equities, at fair value	271,045	265,799
AmTrust Financial Services, Inc.
Debt and Equity Securities, FV-NI [Line Items]
Fair value of indirect investment	$ 245,400	$ 240,100

Investments - Other Investments

Investments - Other Investments, at Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Other Investments [Line Items]
Other investments, at fair value	$ 3,704,870		$ 3,704,870		$ 2,518,031
Valuation lag period			3 months
Additional subscriptions			$ (812,586)	$ (731,588)
Hedge funds
Other Investments [Line Items]
Other investments, at fair value	2,087,091		2,087,091		1,121,904
Fixed income funds
Other Investments [Line Items]
Other investments, at fair value	684,031		684,031		481,039
Equity funds
Other Investments [Line Items]
Other investments, at fair value	290,129		290,129		410,149
Private equity funds
Other Investments [Line Items]
Other investments, at fair value	320,455		320,455		323,496
CLO equities
Other Investments [Line Items]
Other investments, at fair value	84,532		84,532		87,555
CLO equity funds
Other Investments [Line Items]
Other investments, at fair value	140,458		140,458		87,509
Private credit funds
Other Investments [Line Items]
Other investments, at fair value	90,476		90,476		0
Other
Other Investments [Line Items]
Other investments, at fair value	7,698		7,698		$ 6,379
Other investments
Other Investments [Line Items]
Unrealized gain on investment	420,169	$ 3,879	670,653	$ 269,681
Additional subscriptions			(530,300)
Unfunded commitments	$ 792,200		$ 792,200

Investments - Other Investmen_2

Investments - Other Investments at Fair Value by Notice Period (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Other investments, at fair value	$ 3,704,870	$ 2,518,031
Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	2,087,091	1,121,904
Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	684,031	481,039
Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	290,129	410,149
Private equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	320,455	323,496
CLO equities
Schedule of Investments [Line Items]
Other investments, at fair value	84,532	87,555
CLO equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	140,458	87,509
Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value	90,476	0
Other
Schedule of Investments [Line Items]
Other investments, at fair value	7,698	$ 6,379
Less than 1 Year
Schedule of Investments [Line Items]
Other investments, at fair value	1,940,859
Less than 1 Year | Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	793,268
Less than 1 Year | Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	671,333
Less than 1 Year | Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	290,129
Less than 1 Year | 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	84,532
Less than 1 Year | CLO equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	101,597
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
1-2 years
Schedule of Investments [Line Items]
Other investments, at fair value	1,170,618
1-2 years | Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	1,131,505
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 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	29,113
1-2 years | Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value	10,000
1-2 years | Other
Schedule of Investments [Line Items]
Other investments, at fair value
2-3 years
Schedule of Investments [Line Items]
Other investments, at fair value	112,348
2-3 years | Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	102,600
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 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	9,748
2-3 years | Private credit funds
Schedule of Investments [Line Items]
Other investments, at fair value
2-3 years | Other
Schedule of Investments [Line Items]
Other investments, at fair value
Not Eligible/ Restricted
Schedule of Investments [Line Items]
Other investments, at fair value	481,045
Not Eligible/ Restricted | Hedge funds
Schedule of Investments [Line Items]
Other investments, at fair value	59,718
Not Eligible/ Restricted | Fixed income funds
Schedule of Investments [Line Items]
Other investments, at fair value	12,698
Not Eligible/ Restricted | Equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	0
Not Eligible/ Restricted | Private equity funds
Schedule of Investments [Line Items]
Other investments, at fair value	320,455
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	80,476
Not Eligible/ Restricted | Other
Schedule of Investments [Line Items]
Other investments, at fair value	$ 7,698

Investments - Equity Method Inv

Investments - Equity Method Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Investment	$ 299,823	$ 266,823
Ownership %	47.40%	47.40%
Equity method investments	$ 516,795	$ 326,277
Enhanzed Re
Schedule of Equity Method Investments [Line Items]
Investment	$ 154,050	$ 154,050
Ownership %	47.40%	47.40%
Equity method investments	$ 271,678	$ 182,856
Citco
Schedule of Equity Method Investments [Line Items]
Investment	$ 50,000	$ 50,000
Ownership %	31.90%	31.90%
Equity method investments	$ 51,946	$ 51,742
Monument Re (1)
Schedule of Equity Method Investments [Line Items]
Investment	$ 59,600	$ 26,600
Ownership %	23.00%	23.50%
Equity method investments	$ 161,994	$ 60,598
Monument Re (1) | Common Stock
Schedule of Equity Method Investments [Line Items]
Ownership %	20.00%	20.00%
Clear Spring
Schedule of Equity Method Investments [Line Items]
Investment	$ 11,210	$ 11,210
Ownership %	20.00%	20.00%
Equity method investments	$ 10,944	$ 10,645
Other
Schedule of Equity Method Investments [Line Items]
Investment	$ 24,963	$ 24,963
Ownership %	30.00%	30.00%
Equity method investments	$ 20,233	$ 20,436
Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Unfunded commitments	$ 68,700

Investments - Funds Held Direct

Investments - Funds Held Directly Managed Components (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Funds Held, Directly Managed [Line Items]
Funds held - directly managed	$ 1,066,639	$ 1,187,552
Funds held - directly managed
Schedule of Funds Held, Directly Managed [Line Items]
Debt securities, trading	1,054,201	1,173,345
Cash and cash equivalents	6,432	10,296
Funds held - directly managed, other assets	6,006	3,911
Funds held - directly managed	$ 1,066,639	$ 1,187,552

Investments - Funds Held Dire_2

Investments - Funds Held Directly Managed - Fixed Maturity Components (Details) - USD ($) $ in Thousands	Sep. 30, 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	$ 106,768	$ 185,859
Net unrealized gains (losses):
Change in fair value - fair value option accounting	9,077	5,438
Change in fair value - embedded derivative accounting	0	0
Debt securities, trading	115,845	191,297
Funds held - Directly Managed - Variable Return
Schedule of Funds Held, Directly Managed [Line Items]
Fixed maturity investments, at amortized cost	861,511	940,194
Net unrealized gains (losses):
Change in fair value - fair value option accounting	0	0
Change in fair value - embedded derivative accounting	76,845	41,854
Debt securities, trading	938,356	982,048
Funds held - directly managed
Schedule of Funds Held, Directly Managed [Line Items]
Fixed maturity investments, at amortized cost	968,279	1,126,053
Net unrealized gains (losses):
Change in fair value - fair value option accounting	9,077	5,438
Change in fair value - embedded derivative accounting	76,845	41,854
Debt securities, trading	$ 1,054,201	$ 1,173,345

Investments - Funds Held Dire_3

Investments - Funds Held Directly Managed Narrative (Details) - USD ($) $ in Thousands	Jun. 01, 2020	Sep. 30, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Funds held by reinsured companies		$ 657,490	$ 475,732
Aspen
Business Acquisition [Line Items]
Reinsurance premium consideration	$ 770,000
AXA Group
Business Acquisition [Line Items]
Reinsurance premium consideration	$ 24,500	$ 204,200

Investments - Net Investment In

Investments - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Investment Income [Line Items]
Gross investment income	$ 74,921	$ 84,141	$ 251,556	$ 240,796
Investment expenses	(2,791)	(2,639)	(10,269)	(9,372)
Net investment income	72,130	81,502	241,287	231,424
Fixed maturity investments
Net Investment Income [Line Items]
Gross investment income	47,275	54,085	153,554	163,246
Short-term investments and cash and cash equivalents
Net Investment Income [Line Items]
Gross investment income	826	3,526	4,203	11,430
Funds held
Net Investment Income [Line Items]
Gross investment income	8,346	10,091	32,715	18,901
Funds held - directly managed
Net Investment Income [Line Items]
Gross investment income	7,703	9,381	27,204	28,742
Investment income from fixed maturities and cash and cash equivalents
Net Investment Income [Line Items]
Gross investment income	64,150	77,083	217,676	222,319
Equity investments
Net Investment Income [Line Items]
Gross investment income	4,771	4,416	14,496	11,218
Other investments
Net Investment Income [Line Items]
Gross investment income	6,000	2,642	19,384	7,259
Investment income from equities and other investments
Net Investment Income [Line Items]
Gross investment income	$ 10,771	$ 7,058	$ 33,880	$ 18,477

Investments - Net Realized and

Investments - Net Realized and Unrealized Gains (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net realized gains (losses) on sale:
Gross realized gains on fixed maturity securities, AFS	$ 9,871	$ 44	$ 19,995	$ 4,493
Gross realized losses on fixed maturity securities, AFS	(786)	(10)	(7,379)	(302)
Credit recoveries (losses) on fixed maturity securities, AFS	(2,379)	0	71	0
Net realized investment gains (losses) on derivatives	46	0	46	0
Total net realized gains on sale	53,488	23,389	114,894	49,243
Net unrealized gains (losses):
Total net unrealized gains	446,517	121,671	723,658	809,246
Net realized and unrealized gains	500,005	145,060	838,552	858,489
Sales of available-for-sale securities	409,600	7,600	1,455,900	91,200
Fixed maturity securities
Net realized gains (losses) on sale:
Gross realized gains on fixed maturity securities, AFS	9,871	44	19,995	4,493
Gross realized losses on fixed maturity securities, AFS	(786)	(10)	(7,379)	(302)
Credit recoveries (losses) on fixed maturity securities, AFS	2,248	0	(389)	0
Net realized gains (losses) on fixed maturity securities	30,531	25,245	87,911	45,636
Net unrealized gains (losses):
Fixed maturity securities	14,324	86,840	58,795	413,175
Funds held - directly managed
Net realized gains (losses) on sale:
Net realized gains (losses) on fixed maturity securities	3,292	1,991	5,545	629
Net unrealized gains (losses):
Fixed maturity securities	7,814	20,895	42,619	95,124
Equity investments
Net realized gains (losses) on sale:
Net realized gains (losses) on equity investments	8,286	(3,881)	9,165	(1,213)
Net unrealized gains (losses):
Equity investments	4,210	10,057	(48,409)	31,266
Other Investments
Net unrealized gains (losses):
Other Investments	$ 420,169	$ 3,879	$ 670,653	$ 269,681

Investments - Reconciliation to

Investments - Reconciliation to Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt Securities, Available-for-sale [Line Items]
Gross realized gains on fixed maturity securities, AFS	$ 9,871	$ 44	$ 19,995	$ 4,493
Gross realized gains on fixed maturity securities, AFS	(786)	(10)	(7,379)	(302)
Total reclassification adjustment	9,488	34	13,498	4,191
Credit recoveries (losses) on fixed maturity securities, AFS	2,379	0	(71)	0
Continuing Operations
Debt Securities, Available-for-sale [Line Items]
Credit recoveries (losses) on fixed maturity securities, AFS	2,248	0	(389)	0
Discontinued Operations
Debt Securities, Available-for-sale [Line Items]
Gross realized gains on fixed maturity securities, AFS	489	12	1,025	12
Gross realized gains on fixed maturity securities, AFS	(86)	(12)	(143)	(12)
Credit recoveries (losses) on fixed maturity securities, AFS	$ 131	$ 0	$ 318	$ 0

Investments - Restricted Assets

Investments - Restricted Assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)Segment	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)
Line of Credit Facility [Line Items]
Restricted cash and cash equivalents	$ 556,721	$ 346,877	$ 497,315
Collateral in trust for third party agreements	5,189,537	4,103,847
Assets on deposit with regulatory authorities	276,941	309,659
Funds at Lloyd's	546,996	639,316
Restricted assets, total	$ 6,135,174	5,185,492
Number of syndicates | Segment	3
Asset Pledged as Collateral
Line of Credit Facility [Line Items]
Collateral for secured letter of credit facilities	$ 121,700	$ 132,670

Derivative and Hedging Instru_3

Derivative and Hedging Instruments - Foreign Currency Hedging of Net Investments (Details) - Currency forward contracts - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivatives qualifying as hedges
Derivative [Line Items]
Gross Notional Amount	$ 538,755		$ 538,755		$ 495,291
Assets	6,785		6,785		642
Liabilities	0		0		11,452
Net gains (losses) on qualifying derivative hedges	(19,653)	$ 14,713	2,224	$ 13,564
Derivatives qualifying as hedges | AUD
Derivative [Line Items]
Gross Notional Amount	68,847		68,847		64,620
Assets	282		282		52
Liabilities	0		0		2,033
Net gains (losses) on qualifying derivative hedges	(2,813)	1,673	(1,777)	1,819
Derivatives qualifying as hedges | EUR
Derivative [Line Items]
Gross Notional Amount	140,663		140,663		112,284
Assets	839		839		246
Liabilities	0		0		1,635
Net gains (losses) on qualifying derivative hedges	(5,525)	4,780	(6,001)	5,076
Derivatives qualifying as hedges | GBP
Derivative [Line Items]
Gross Notional Amount	329,245		329,245		318,387
Assets	5,664		5,664		344
Liabilities	0		0		7,784
Net gains (losses) on qualifying derivative hedges	(11,315)	8,260	10,002	6,669
Derivatives not qualifying as hedges
Derivative [Line Items]
Gross Notional Amount	136,814		136,814		153,563
Assets	1,414		1,414		1,369
Liabilities	302		302		4,106
Gains (Losses) on non-qualifying-hedges included in net earnings	(4,194)	15,862	584	17,114
Derivatives not qualifying as hedges | AUD
Derivative [Line Items]
Gross Notional Amount	19,076		19,076		913
Assets	145		145		839
Liabilities	81		81		892
Gains (Losses) on non-qualifying-hedges included in net earnings	13	1,148	(432)	1,710
Derivatives not qualifying as hedges | EUR
Derivative [Line Items]
Gross Notional Amount	22,272		22,272		74,444
Assets	0		0		507
Liabilities	132		132		1,440
Gains (Losses) on non-qualifying-hedges included in net earnings	(817)	2,473	135	3,344
Derivatives not qualifying as hedges | GBP
Derivative [Line Items]
Gross Notional Amount	43,254		43,254		11,940
Assets	744		744		13
Liabilities	0		0		292
Gains (Losses) on non-qualifying-hedges included in net earnings	(2,219)	10,659	(719)	12,970
Derivatives not qualifying as hedges | CAD
Derivative [Line Items]
Gross Notional Amount	52,212		52,212		66,266
Assets	525		525		10
Liabilities	89		89		$ 1,482
Gains (Losses) on non-qualifying-hedges included in net earnings	$ (1,171)	$ 1,582	$ 1,600	$ (910)

Derivative and Hedging Instru_4

Derivative and Hedging Instruments - Summary of Derivative Instruments (Details) $ in Thousands	Sep. 30, 2020USD ($)
Credit Risk, Government Bond Future, Foreign Currency Forward Contracts
Derivative [Line Items]
Gross Notional Amount	$ 22,287
Assets	112
Liabilities	283
Credit default swaps
Derivative [Line Items]
Gross Notional Amount	7,865
Assets	0
Liabilities	169
Futures contracts | Long positions
Derivative [Line Items]
Gross Notional Amount	48,051
Assets	100
Liabilities	0
Futures contracts | Short positions
Derivative [Line Items]
Gross Notional Amount	(33,318)
Assets	0
Liabilities	85
Currency forward contracts | Long positions
Derivative [Line Items]
Gross Notional Amount	1,508
Assets	12
Liabilities	0
Currency forward contracts | Short positions
Derivative [Line Items]
Gross Notional Amount	(1,819)
Assets	0
Liabilities	$ 29

Derivative and Hedging Instru_5

Derivative and Hedging Instruments - Net Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Derivative [Line Items]
Total net gains	$ 57	$ 186
Credit default swaps
Derivative [Line Items]
Total net gains	106	106
Futures contracts
Derivative [Line Items]
Total net gains	(6)	(43)
Currency forward contracts
Derivative [Line Items]
Total net gains	$ (43)	$ 123

Derivative and Hedging Instru_6

Derivative and Hedging Instruments - Investments in Call Options on Equities (Details) - Derivatives not qualifying as hedges - Call options on equity - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Unrealized gain (loss) on equity securities (less than)	$ 0	$ 100,000	$ 100,000	$ 1,300,000
Cost						$ 10,000,000
Fair value of derivatives (less than)					$ 100,000

Derivative and Hedging Instru_7

Derivative and Hedging Instruments - Forward Interest Rate Swaps (Details) - Interest Rate Swap $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended
	Sep. 30, 2020USD ($)	Apr. 07, 2020USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Oct. 31, 2019AUD ($)
Derivative [Line Items]
Notional amount of derivative					$ 120
Unrealized gain on equity securities (less than)	$ 0		$ 800,000
Gain on derivative		$ 500,000
Carrying Value
Derivative [Line Items]
Liabilities				$ 300,000

Reinsurance Balances Recovera_3

Reinsurance Balances Recoverable on Paid and Unpaid Losses - Total Reinsurance Balances (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Effects of Reinsurance [Line Items]
Outstanding losses	$ 1,117,203		$ 1,245,435
IBNR	582,667		785,530
ULAE	7,674
Fair value adjustments - acquired companies	(13,364)		(15,255)
Fair value adjustments - fair value option	(27,029)		(88,086)
Total reinsurance reserves recoverable	1,667,151	$ 1,858,161	1,927,624	$ 1,876,613	$ 1,873,766	$ 1,708,272
Paid losses recoverable	214,505		253,510
Total	1,881,656		2,181,134
Reinsurance balances recoverable on paid and unpaid losses	1,338,495		1,485,616
Reinsurance balances recoverable on paid and unpaid losses - fair value option	543,161		695,518
Non-life Run-off
Effects of Reinsurance [Line Items]
Outstanding losses	858,988		972,293
IBNR	439,594		673,059
ULAE	7,674
Fair value adjustments - acquired companies	(11,986)		(13,652)
Fair value adjustments - fair value option	(27,029)		(88,086)
Total reinsurance reserves recoverable	1,267,241	1,429,489	1,543,614	1,488,374	1,534,427	1,366,123
Paid losses recoverable	136,548		181,375
Total	1,403,789		1,724,989
Reinsurance balances recoverable on paid and unpaid losses	860,628		1,029,471
Reinsurance balances recoverable on paid and unpaid losses - fair value option	543,161		695,518
Atrium
Effects of Reinsurance [Line Items]
Outstanding losses			9,011
IBNR			19,286
Fair value adjustments - acquired companies			519
Fair value adjustments - fair value option			0
Total reinsurance reserves recoverable	0	27,250	28,816	31,719	29,606	38,768
Paid losses recoverable			1,541
Total			30,357
Reinsurance balances recoverable on paid and unpaid losses			30,357
Reinsurance balances recoverable on paid and unpaid losses - fair value option			0
StarStone
Effects of Reinsurance [Line Items]
Outstanding losses	258,215		264,131
IBNR	143,073		93,185
ULAE	0
Fair value adjustments - acquired companies	(1,378)		(2,122)
Fair value adjustments - fair value option	0		0
Total reinsurance reserves recoverable	399,910	$ 401,422	355,194	$ 356,520	$ 309,733	$ 303,381
Paid losses recoverable	77,957		70,594
Total	477,867		425,788
Reinsurance balances recoverable on paid and unpaid losses	477,867		425,788
Reinsurance balances recoverable on paid and unpaid losses - fair value option	$ 0		$ 0

Reinsurance Balances Recovera_4

Reinsurance Balances Recoverable on Paid and Unpaid Losses - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 30, 2020
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable		$ 1,881,656		$ 2,181,134
Increase (decrease) in reinsurance recoverable		(266,289)	$ 207,579
Accounting standards update	us-gaap:AccountingStandardsUpdate201613Member			us-gaap:AccountingStandardsUpdate201613Member
Allowance for estimated uncollectible reinsurance		135,117		$ 147,639	$ 143,653
Non-Life Run-Off and StarStone Segment
Effects of Reinsurance [Line Items]
Increase (decrease) in reinsurance recoverable		$ (299,500)
Cumulative effect of change in accounting principle
Effects of Reinsurance [Line Items]
Allowance for estimated uncollectible reinsurance				$ (195)	$ 0

Reinsurance Balances Recovera_5

Reinsurance Balances Recoverable on Paid and Unpaid Losses - Top Ten Reinsurers (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)reinsurer	Dec. 31, 2019USD ($)reinsurer
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 1,881,656	$ 2,181,134
Reinsurance balances recoverable | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 1,881,656	$ 2,181,134
Concentration risk percentage	100.00%	100.00%
Reinsurance balances recoverable | Top 10 reinsurers | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 1,172,923	$ 1,471,604
Concentration risk percentage	62.30%	67.40%
Reinsurance balances recoverable | Other reinsurers greater than $1 million | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 688,672	$ 688,732
Concentration risk percentage	36.60%	31.60%
Reinsurance balances recoverable | Other reinsurers less than $1 million | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 20,061	$ 20,798
Concentration risk percentage	1.10%	1.00%
Reinsurance balances recoverable | Top 10 Total | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 910,751	$ 1,199,479
Number of external reinsurers | reinsurer	8	8
Reinsurance balances recoverable | Top Ten Reinsurers, Four Non-Rated Reinsurers | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 262,172	$ 272,125
Number of external reinsurers | reinsurer	2	2
Reinsurance balances recoverable | Top Ten Reinsurers, Non-Rated Reinsurers, US State Backed | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 183,400	$ 190,800
Reinsurance balances recoverable | Top Ten Reinsurers, Non-Rated Reinsurers, Provided Security | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	78,800	81,400
Non-life Run-off
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	1,403,789	1,724,989
Non-life Run-off | Reinsurance balances recoverable | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	1,403,789	1,724,989
Non-life Run-off | Reinsurance balances recoverable | Top 10 reinsurers | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	828,479	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	556,623	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	18,687	19,243
Atrium
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable		30,357
Atrium | Reinsurance balances recoverable | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable		30,357
Atrium | Reinsurance balances recoverable | Top 10 reinsurers | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable		22,051
Atrium | Reinsurance balances recoverable | Other reinsurers greater than $1 million | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable		7,761
Atrium | Reinsurance balances recoverable | Other reinsurers less than $1 million | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable		545
StarStone
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	477,867	425,788
StarStone | Reinsurance balances recoverable | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	477,867	425,788
StarStone | Reinsurance balances recoverable | Top 10 reinsurers | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	344,444	295,443
StarStone | Reinsurance balances recoverable | Other reinsurers greater than $1 million | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	132,049	129,335
StarStone | Reinsurance balances recoverable | Other reinsurers less than $1 million | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	1,374	1,010
Equity Method Investee | Hannover Ruck | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	0	259,077
Equity Method Investee | Lloyds of London | Reinsurer Concentration Risk
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 346,601	$ 396,246

Reinsurance Balances Recovera_6

Reinsurance Balances Recoverable on Paid and Unpaid Losses - Summary of Provisions for Uncollectible Reinsurance Balances Recoverable by Rating of Reinsurer (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Effects of Reinsurance [Line Items]
Gross	$ 2,016,773		$ 2,328,773
Allowance for estimated uncollectible reinsurance	135,117	$ 143,653	147,639
Total	$ 1,881,656		$ 2,181,134
Provisions as a % of Gross	6.70%		6.30%
Reinsurers rated A- or above
Effects of Reinsurance [Line Items]
Gross	$ 1,429,984		$ 1,731,270
Allowance for estimated uncollectible reinsurance	57,465		43,427
Total	$ 1,372,519		$ 1,687,843
Provisions as a % of Gross	4.00%		2.50%
Secured | Reinsurers rated below A-
Effects of Reinsurance [Line Items]
Gross	$ 419,431		$ 463,840
Allowance for estimated uncollectible reinsurance	0		0
Total	$ 419,431		$ 463,840
Provisions as a % of Gross	0.00%		0.00%
Unsecured | Reinsurers rated below A-
Effects of Reinsurance [Line Items]
Gross	$ 167,358		$ 133,663
Allowance for estimated uncollectible reinsurance	77,652		104,212
Total	$ 89,706		$ 29,451
Provisions as a % of Gross	46.40%		78.00%

Reinsurance Balances Recovera_7

Reinsurance Balances Recoverable on Paid and Unpaid Losses Reinsurance Balances Recoverable on Paid and Unpaid Losses - Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for estimated uncollectible reinsurance, beginning of period	$ 143,653	$ 147,639
Effect of exchange rate movement	745	(701)
Current period change in the allowance	815	(718)
Write-offs charged against the allowance	(9,625)	(10,225)
Recoveries collected	(471)	(683)
Allowance for estimated uncollectible reinsurance, end of period	135,117	135,117
Cumulative effect of change in accounting principle
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for estimated uncollectible reinsurance, beginning of period	$ 0	$ (195)

Deferred Charge Assets (Details

Deferred Charge Assets (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning carrying value	$ 258,516,000	$ 99,094,000	$ 272,462,000	$ 86,585,000
Recorded during the period	0	85,183,000	11,746,000	108,689,000
Amortization	(10,316,000)	(17,009,000)	(36,008,000)	(28,006,000)
Ending carrying value	$ 248,200,000	$ 167,268,000	248,200,000	$ 167,268,000
Impairment loss of deferred charge assets			$ 0

Losses and Loss Adjustment Ex_3

Losses and Loss Adjustment Expenses - Balance Sheet Summary by Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	$ 5,170,451		$ 5,249,564
IBNR	4,987,866		4,651,650
Fair value adjustments - acquired companies	(147,839)		(167,511)
Fair value adjustments - fair value option	(81,299)		(217,933)
ULAE	371,705		352,634
Total	10,300,884	$ 10,593,436	9,868,404	$ 9,516,646	$ 9,354,891	$ 9,048,796
Loss and loss adjustment expenses	7,878,206		7,247,282
Loss and loss adjustment expenses, at fair value	2,422,678		2,621,122
Non-life Run-off
Liability for Claims and Claims Adjustment Expense [Line Items]
Total	8,923,590	8,979,234	8,295,361	7,939,691	7,803,663	7,540,662
Atrium
Liability for Claims and Claims Adjustment Expense [Line Items]
Total	0	239,731	231,672	231,679	222,576	241,284
StarStone
Liability for Claims and Claims Adjustment Expense [Line Items]
Total	1,350,998	$ 1,349,763	1,318,294	$ 1,320,952	$ 1,305,026	$ 1,247,989
Operating Segments | Non-life Run-off
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	4,461,854		4,407,082
IBNR	4,360,063		3,945,407
Fair value adjustments - acquired companies	(147,500)		(170,689)
Fair value adjustments - fair value option	(81,299)		(217,933)
ULAE	330,472		331,494
Total	8,923,590		8,295,361
Loss and loss adjustment expenses	6,500,912		5,674,239
Loss and loss adjustment expenses, at fair value	2,422,678		2,621,122
Operating Segments | Atrium
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses			89,141
IBNR			136,543
Fair value adjustments - acquired companies			3,700
Fair value adjustments - fair value option			0
ULAE			2,288
Total			231,672
Loss and loss adjustment expenses			231,672
Loss and loss adjustment expenses, at fair value			0
Operating Segments | StarStone
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	698,118		743,829
IBNR	611,986		556,135
Fair value adjustments - acquired companies	(339)		(522)
Fair value adjustments - fair value option	0		0
ULAE	41,233		18,852
Total	1,350,998		1,318,294
Loss and loss adjustment expenses	1,350,998		1,318,294
Loss and loss adjustment expenses, at fair value	0		0
Other
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	10,479		9,512
IBNR	15,817		13,565
Fair value adjustments - acquired companies	0		0
Fair value adjustments - fair value option	0		0
ULAE	0		0
Total	26,296		23,077
Loss and loss adjustment expenses	26,296		23,077
Loss and loss adjustment expenses, at fair value	$ 0		$ 0

Losses and Loss Adjustment Ex_4

Losses and Loss Adjustment Expenses - Reconciliation of Beginning and Ending Reserves for Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2018
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as of beginning of period	$ 10,593,436	$ 9,868,404	$ 9,354,891	$ 9,868,404	$ 9,048,796	$ 9,048,796
Less: reinsurance reserves recoverable	1,858,161	1,927,624	1,873,766	1,927,624	1,708,272	1,708,272
Less: deferred charge assets on retroactive reinsurance	258,516	272,462	99,094	272,462	86,585	86,585
Net balance as of beginning of period	8,476,759	$ 7,667,675	7,382,031	7,667,675	7,253,939	7,253,939
Net incurred losses and LAE:
Current period	78,965		156,344	314,083	457,720
Prior periods	30,721		6,914	25,595	108,391
Total net incurred losses and LAE	109,686		163,258	339,678	566,111
Net paid losses:
Current period	(17,194)		(36,733)	(32,304)	(107,679)
Prior periods	(344,060)		(397,514)	(1,070,063)	(1,255,903)
Total net paid losses	(361,254)		(434,247)	(1,102,367)	(1,363,582)
Effect of exchange rate movement	99,129		(83,277)	(6,139)	(95,270)
Acquired on purchase of subsidiaries	0		0	0	686
Assumed business	280,497		445,000	1,705,970	1,110,881
Reclassification to assets and liabilities held-for-sale	(219,284)		0	(219,284)	0
Net balance as of September 30	8,385,533		7,472,765	8,385,533	7,472,765	7,667,675
Plus: reinsurance reserves recoverable	1,667,151		1,876,613	1,667,151	1,876,613	1,927,624
Plus: deferred charge assets on retroactive reinsurance	248,200		167,268	248,200	167,268	272,462
Balance as of September 30	10,300,884		9,516,646	10,300,884	9,516,646	$ 9,868,404
Accounting standards update		us-gaap:AccountingStandardsUpdate201613Member				us-gaap:AccountingStandardsUpdate201613Member
Non-life Run-off
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as of beginning of period	8,979,234	$ 8,295,361	7,803,663	8,295,361	7,540,662	$ 7,540,662
Less: reinsurance reserves recoverable	1,429,489	1,543,614	1,534,427	1,543,614	1,366,123	1,366,123
Less: deferred charge assets on retroactive reinsurance	258,516	272,462	99,094	272,462	86,585	86,585
Net balance as of beginning of period	7,291,229	6,479,988	6,170,142	6,479,988	6,087,954	6,087,954
Net incurred losses and LAE:
Current period	8,218		23,845	24,153	107,291
Prior periods	26,040		6,738	39,545	28,226
Total net incurred losses and LAE	34,258		30,583	63,698	135,517
Net paid losses:
Current period	(739)		(14,374)	(1,777)	(53,265)
Prior periods	(283,143)		(274,071)	(824,473)	(913,352)
Total net paid losses	(283,882)		(288,445)	(826,250)	(966,617)
Effect of exchange rate movement	86,047		(73,231)	(15,257)	(84,372)
Acquired on purchase of subsidiaries	0		0	0	686
Assumed business	280,497		445,000	1,705,970	1,110,881
Reclassification to assets and liabilities held-for-sale	0		0	0	0
Net balance as of September 30	7,408,149		6,284,049	7,408,149	6,284,049	6,479,988
Plus: reinsurance reserves recoverable	1,267,241		1,488,374	1,267,241	1,488,374	1,543,614
Plus: deferred charge assets on retroactive reinsurance	248,200		167,268	248,200	167,268	272,462
Balance as of September 30	8,923,590		7,939,691	8,923,590	7,939,691	8,295,361
Atrium
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as of beginning of period	239,731	231,672	222,576	231,672	241,284	241,284
Less: reinsurance reserves recoverable	27,250	28,816	29,606	28,816	38,768	38,768
Net balance as of beginning of period	212,481	202,005	192,970	202,005	202,516	202,516
Net incurred losses and LAE:
Current period	23,129		27,093	70,075	63,189
Prior periods	(1,134)		1,307	(4,072)	(4,527)
Total net incurred losses and LAE	21,995		28,400	66,003	58,662
Net paid losses:
Current period	(7,717)		(9,387)	(17,004)	(24,531)
Prior periods	(9,472)		(10,618)	(31,412)	(35,564)
Total net paid losses	(17,189)		(20,005)	(48,416)	(60,095)
Effect of exchange rate movement	1,997		(1,405)	(308)	(1,123)
Reclassification to assets and liabilities held-for-sale	(219,284)		0	(219,284)	0
Net balance as of September 30	0		199,960	0	199,960	202,005
Plus: reinsurance reserves recoverable	0		31,719	0	31,719	28,816
Balance as of September 30	0		231,679	0	231,679	231,672
StarStone
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as of beginning of period	1,349,763	1,318,294	1,305,026	1,318,294	1,247,989	1,247,989
Less: reinsurance reserves recoverable	401,422	355,194	309,733	355,194	303,381	303,381
Net balance as of beginning of period	948,341	$ 962,605	995,293	962,605	944,608	944,608
Net incurred losses and LAE:
Current period	44,734		101,808	208,414	274,070
Prior periods	3,656		(1,180)	(11,155)	84,794
Total net incurred losses and LAE	48,390		100,628	197,259	358,864
Net paid losses:
Current period	(7,755)		(11,653)	(12,142)	(27,624)
Prior periods	(48,972)		(111,195)	(206,058)	(301,641)
Total net paid losses	(56,727)		(122,848)	(218,200)	(329,265)
Effect of exchange rate movement	11,084		(8,641)	9,424	(9,775)
Net balance as of September 30	951,088		964,432	951,088	964,432	962,605
Plus: reinsurance reserves recoverable	399,910		356,520	399,910	356,520	355,194
Balance as of September 30	$ 1,350,998		$ 1,320,952	$ 1,350,998	$ 1,320,952	1,318,294
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						643	$ 0	$ 0	$ 0
Cumulative effect of change in accounting principle | Discontinued Operations, Held-for-sale | StarStone US
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Less: cumulative effect of change in accounting principal on allowance for estimated uncollectible reinsurance						400
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	0	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	0	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						$ 495	$ 0	$ 0	$ 0

Losses and Loss Adjustment Ex_5

Losses and Loss Adjustment Expenses - Net (Reduction) Increase in Ultimate Losses and Loss Adjustment Expense Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Prior Period
Net losses paid	$ 344,060	$ 397,514	$ 1,070,063	$ 1,255,903
Net incurred losses and LAE, prior period	30,721	6,914	25,595	108,391
Current Period
Net losses paid	17,194	36,733	32,304	107,679
Net incurred losses and LAE, current period	78,965	156,344	314,083	457,720
Total
Net losses paid	361,254	434,247	1,102,367	1,363,582
Net change in case and LAE reserves	(41,627)	(190,111)	(356,860)	(355,078)
Net change in IBNR reserves	(226,509)	(144,778)	(548,468)	(603,357)
Increase (reduction) in estimates of net ultimate losses	93,118	99,358	197,039	405,147
Increase (reduction) in provisions for unallocated LAE	(19,654)	(12,346)	(11,063)	(37,490)
Amortization of deferred charge assets	10,316	17,009	36,008	28,006
Amortization of fair value adjustments	4,864	17,863	20,846	35,071
Changes in fair value - fair value option	21,042	41,374	96,848	135,377
Total net incurred losses and LAE	109,686	163,258	339,678	566,111
Non-life Run-off
Prior Period
Net losses paid	283,143	274,071	824,473	913,352
Net change in case and LAE reserves	(49,854)	(175,830)	(301,382)	(394,780)
Net change in IBNR reserves	(229,312)	(155,315)	(603,546)	(649,053)
Increase (reduction) in estimates of net ultimate losses	3,977	(57,074)	(80,455)	(130,481)
Increase (reduction) in provisions for unallocated LAE	(14,605)	(12,109)	(34,509)	(38,709)
Amortization of deferred charge assets	10,316	17,009	36,008	28,006
Amortization of fair value adjustments	5,310	17,538	21,653	34,033
Changes in fair value - fair value option	21,042	41,374	96,848	135,377
Net incurred losses and LAE, prior period	26,040	6,738	39,545	28,226
Current Period
Net losses paid	739	14,374	1,777	53,265
Net change in case and LAE reserves	(33)	2,726	809	24,141
Net change in IBNR reserves	7,512	6,794	21,567	29,405
Increase (reduction) in estimates of net ultimate losses	8,218	23,894	24,153	106,811
Increase (reduction) in provisions for unallocated LAE	0	(49)	0	480
Amortization of deferred charge assets	0	0	0	0
Amortization of fair value adjustments	0	0	0	0
Changes in fair value - fair value option	0	0	0	0
Net incurred losses and LAE, current period	8,218	23,845	24,153	107,291
Total
Net losses paid	283,882	288,445	826,250	966,617
Net change in case and LAE reserves	(49,887)	(173,104)	(300,573)	(370,639)
Net change in IBNR reserves	(221,800)	(148,521)	(581,979)	(619,648)
Increase (reduction) in estimates of net ultimate losses	12,195	(33,180)	(56,302)	(23,670)
Increase (reduction) in provisions for unallocated LAE	(14,605)	(12,158)	(34,509)	(38,229)
Amortization of deferred charge assets	10,316	17,009	36,008	28,006
Amortization of fair value adjustments	5,310	17,538	21,653	34,033
Changes in fair value - fair value option	21,042	41,374	96,848	135,377
Total net incurred losses and LAE	34,258	30,583	63,698	135,517
Atrium
Prior Period
Net losses paid	9,472	10,618	31,412	35,564
Net change in case and LAE reserves	(2,292)	(2,860)	(9,517)	(13,032)
Net change in IBNR reserves	(8,110)	(6,235)	(25,769)	(27,787)
Increase (reduction) in estimates of net ultimate losses	(930)	1,523	(3,874)	(5,255)
Increase (reduction) in provisions for unallocated LAE	48	0	48	0
Amortization of fair value adjustments	(252)	(216)	(246)	728
Net incurred losses and LAE, prior period	(1,134)	1,307	(4,072)	(4,527)
Current Period
Net losses paid	7,717	9,387	17,004	24,531
Net change in case and LAE reserves	4,993	2,769	13,152	12,787
Net change in IBNR reserves	10,496	14,937	39,996	25,871
Increase (reduction) in estimates of net ultimate losses	23,206	27,093	70,152	63,189
Increase (reduction) in provisions for unallocated LAE	(77)	0	(77)	0
Amortization of fair value adjustments	0	0	0	0
Net incurred losses and LAE, current period	23,129	27,093	70,075	63,189
Total
Net losses paid	17,189	20,005	48,416	60,095
Net change in case and LAE reserves	2,701	(91)	3,635	(245)
Net change in IBNR reserves	2,386	8,702	14,227	(1,916)
Increase (reduction) in estimates of net ultimate losses	22,276	28,616	66,278	57,934
Increase (reduction) in provisions for unallocated LAE	(29)	0	(29)	0
Amortization of deferred charge assets	0	0	0	0
Amortization of fair value adjustments	(252)	(216)	(246)	728
Changes in fair value - fair value option	0	0	0	0
Total net incurred losses and LAE	21,995	28,400	66,003	58,662
StarStone
Prior Period
Net losses paid	48,972	111,195	206,058	301,641
Net change in case and LAE reserves	(20,068)	(8,866)	(85,798)	(22,538)
Net change in IBNR reserves	(24,755)	(101,938)	(130,738)	(192,034)
Increase (reduction) in estimates of net ultimate losses	4,149	391	(10,478)	87,069
Increase (reduction) in provisions for unallocated LAE	(299)	(2,112)	(116)	(2,585)
Amortization of fair value adjustments	(194)	541	(561)	310
Net incurred losses and LAE, prior period	3,656	(1,180)	(11,155)	84,794
Current Period
Net losses paid	7,755	11,653	12,142	27,624
Net change in case and LAE reserves	25,524	(8,994)	24,911	36,046
Net change in IBNR reserves	16,176	97,225	147,770	207,076
Increase (reduction) in estimates of net ultimate losses	49,455	99,884	184,823	270,746
Increase (reduction) in provisions for unallocated LAE	(4,721)	1,924	23,591	3,324
Amortization of fair value adjustments	0	0	0	0
Net incurred losses and LAE, current period	44,734	101,808	208,414	274,070
Total
Net losses paid	56,727	122,848	218,200	329,265
Net change in case and LAE reserves	5,456	(17,860)	(60,887)	13,508
Net change in IBNR reserves	(8,579)	(4,713)	17,032	15,042
Increase (reduction) in estimates of net ultimate losses	53,604	100,275	174,345	357,815
Increase (reduction) in provisions for unallocated LAE	(5,020)	(188)	23,475	739
Amortization of deferred charge assets	0	0	0	0
Amortization of fair value adjustments	(194)	541	(561)	310
Changes in fair value - fair value option	0	0	0	0
Total net incurred losses and LAE	48,390	100,628	197,259	358,864
Other
Total
Net losses paid	3,456	2,949	9,501	7,605
Net change in case and LAE reserves	103	944	965	2,298
Net change in IBNR reserves	1,484	(246)	2,252	3,165
Increase (reduction) in estimates of net ultimate losses	5,043	3,647	12,718	13,068
Increase (reduction) in provisions for unallocated LAE	0	0	0	0
Amortization of deferred charge assets	0	0	0	0
Amortization of fair value adjustments	0	0	0	0
Changes in fair value - fair value option	0	0	0	0
Total net incurred losses and LAE	$ 5,043	$ 3,647	$ 12,718	$ 13,068

Losses and Loss Adjustment Ex_6

Losses and Loss Adjustment Expenses - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Effects of Reinsurance [Line Items]
Net incurred losses and LAE	$ 109,686	$ 163,258	$ 339,678	$ 566,111
Net incurred losses and LAE, current period	78,965	156,344	314,083	457,720
Prior periods	30,721	6,914	25,595	108,391
Net losses paid	344,060	397,514	1,070,063	1,255,903
Motor
Effects of Reinsurance [Line Items]
Unfavorable development	128,400		122,400
Non-life Run-off
Effects of Reinsurance [Line Items]
Net incurred losses and LAE	34,258	30,583	63,698	135,517
Net incurred losses and LAE, current period	8,218	23,845	24,153	107,291
Prior periods	26,040	6,738	39,545	28,226
Changes in fair value - fair value option	21,042	41,374	96,848	135,377
Amortization of deferred charge assets	10,316	17,009	36,008	28,006
Amortization of fair value adjustments	5,310	17,538	21,653	34,033
Increase (reduction) in estimates of net ultimate losses	3,977	(57,074)	(80,455)	(130,481)
Increase (reduction) in provisions for unallocated LAE	(14,605)	(12,109)	(34,509)	(38,709)
Net change in case and IBNR reserves	(279,200)	(331,100)	(904,900)	(1,043,800)
Net losses paid	283,143	274,071	824,473	913,352
Atrium
Effects of Reinsurance [Line Items]
Net incurred losses and LAE	21,995	28,400	66,003	58,662
Net incurred losses and LAE, current period	23,129	27,093	70,075	63,189
Prior periods	(1,134)	1,307	(4,072)	(4,527)
Amortization of fair value adjustments	(252)	(216)	(246)	728
Increase (reduction) in estimates of net ultimate losses	(930)	1,523	(3,874)	(5,255)
Increase (reduction) in provisions for unallocated LAE	48	0	48	0
Net losses paid	9,472	10,618	31,412	35,564
StarStone
Effects of Reinsurance [Line Items]
Net incurred losses and LAE	48,390	100,628	197,259	358,864
Net incurred losses and LAE, current period	44,734	101,808	208,414	274,070
Prior periods	3,656	(1,180)	(11,155)	84,794
Amortization of fair value adjustments	(194)	541	(561)	310
Increase (reduction) in estimates of net ultimate losses	4,149	391	(10,478)	87,069
Increase (reduction) in provisions for unallocated LAE	(299)	(2,112)	(116)	(2,585)
Net losses paid	48,972	$ 111,195	206,058	$ 301,641
Exit costs	(4,400)		23,700
COVID-19 | Atrium
Effects of Reinsurance [Line Items]
Net incurred losses and LAE, current period	1,500		14,300
COVID-19 | StarStone
Effects of Reinsurance [Line Items]
Net incurred losses and LAE, current period	$ 1,400		$ 22,800

Defendant Asbestos and Enviro_3

Defendant Asbestos and Environmental Liabilities - Liability for Asbestos and Liability Claims (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Defendant asbestos and environmental liabilities	$ 754,037	$ 808,062	$ 847,685	$ 180,363	$ 184,264	$ 203,320
Estimated future expenses	45,509		51,637
Fair value adjustments	(280,364)		(314,824)
Insurance recoveries related to defendant asbestos and environmental liabilities	447,800		549,593
Fair value adjustments	(82,512)		(100,738)
Insurance balances recoverable	365,288	428,277	448,855	121,237	$ 122,236	$ 135,808
Net liabilities relating to defendant asbestos and environmental exposures	388,749		398,830	$ 59,126
Insurance balance recoverable, allowance for credit loss	5,907	$ 8,346	3,818
Defendant asbestos liabilities
Loss Contingencies [Line Items]
Defendant asbestos and environmental liabilities	980,678		1,100,593
Defendant environmental liabilities
Loss Contingencies [Line Items]
Defendant asbestos and environmental liabilities	$ 8,214		$ 10,279

Defendant Asbestos and Enviro_4

Defendant Asbestos and Environmental Liabilities - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2018
Liability for Asbestos and Environmental Claims [Roll Forward]
Balance as of beginning of period	$ 808,062	$ 847,685	$ 184,264	$ 847,685	$ 203,320	$ 203,320
Less: Insurance balances recoverable	428,277	448,855	122,236	448,855	135,808	135,808
Plus: Cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible insurance balances	5,907			5,907		3,818	$ 8,346
Net balance as of beginning of period		$ 398,830		398,830
Total net paid claims	52,891		(2,204)	51,977	(1,326)
Amounts recorded in other (income) expense:
Reduction in estimates of ultimate net liabilities	(48,439)		0	(75,332)	(4,259)
Reduction in estimated future expenses	(3,124)		(800)	(6,127)	(3,104)
Amortization of fair value adjustments	7,636		102	16,234	303
Total other (income) expense	(43,927)		(698)	(65,225)	(7,060)
Net balance as at September 30	388,749		59,126	388,749	59,126	398,830
Plus: Insurance balances recoverable	365,288		121,237	365,288	121,237	448,855
Balance as at September 30	754,037		180,363	754,037	180,363	$ 847,685
Accounting standards update		us-gaap:AccountingStandardsUpdate201613Member				us-gaap:AccountingStandardsUpdate201613Member
Cumulative effect of change in accounting principle
Liability for Asbestos and Environmental Claims [Roll Forward]
Plus: Cumulative effect of change in accounting principle on the determination of the allowance for estimated uncollectible insurance balances						$ 3,167	$ 0	$ 0	$ 0
Cumulative effect of change in accounting principle, adjusted balance
Liability for Asbestos and Environmental Claims [Roll Forward]
Net balance as of beginning of period	$ 379,785	$ 401,997	$ 62,028	$ 401,997	$ 67,512	67,512
Amounts recorded in other (income) expense:
Net balance as at September 30						$ 401,997

Defendant Asbestos and Enviro_5

Defendant Asbestos and Environmental Liabilities Defendant Asbestos and Environmental Liabilities - Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Liability For Asbestos And Environmental Claims, Allowance for Credit Loss [Roll Forward]
Allowance for estimated uncollectible insurance balances, beginning of period	$ 8,346	$ 3,818
Current period change in the allowance	(2,439)	(1,078)
Allowance for estimated uncollectible insurance balances, end of period	5,907	5,907
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	$ 0	$ 3,167

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Investments:
Equities, at fair value	$ 653,159	$ 726,721
Total Investments	9,222,623	9,034,557
Reinsurance balances recoverable on paid and unpaid losses	(27,029)	(88,086)
Other Assets:
Losses and LAE	2,422,678	2,621,122
U.S. government and agency
Investments:
Total Investments	789,630	696,077
U.K. government
Investments:
Total Investments	114,777	161,772
Corporate
Investments:
Total Investments	5,679,909	5,448,270
Municipal
Investments:
Total Investments	161,839	140,687
Residential mortgage-backed
Investments:
Total Investments	529,239	400,914
Commercial mortgage-backed
Investments:
Total Investments	843,119	813,746
Asset-backed
Investments:
Total Investments	613,663	670,235
Publicly traded equity investments
Investments:
Equities, at fair value	303,932	327,875
Exchange-traded funds
Investments:
Equities, at fair value	78,182	133,047
Private equity funds
Investments:
Equities, at fair value	271,045	265,799
Private equity funds | Significant Unobservable Inputs (Level 3)
Investments:
Other investments	271,000
Recurring
Investments:
Equities, at fair value	653,159	726,721
Total Investments	13,593,090	12,293,516
Cash and cash equivalents	409,407	367,175
Other Assets:
Losses and LAE	2,422,678	2,621,122
Recurring | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	9,222,623	9,034,557
Recurring | Other investments
Investments:
Other investments	3,704,870	2,518,031
Recurring | Reinsurance recoverable
Investments:
Reinsurance balances recoverable on paid and unpaid losses	543,161	695,518
Recurring | Derivative instruments, assets
Other Assets:
Derivative instruments	8,311	2,011
Recurring | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	585	15,558
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Investments:
Equities, at fair value	361,086	430,357
Total Investments	361,086	430,357
Cash and cash equivalents	270,267	144,984
Other Assets:
Losses and LAE	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Reinsurance recoverable
Investments:
Reinsurance balances recoverable on paid and unpaid losses	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments, assets
Other Assets:
Derivative instruments	0	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	0	0
Recurring | Significant Other Observable Inputs (Level 2)
Investments:
Equities, at fair value	21,028	30,565
Total Investments	9,773,824	9,588,546
Cash and cash equivalents	139,140	222,191
Other Assets:
Losses and LAE	0	0
Recurring | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	9,222,623	9,034,557
Recurring | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	517,735	509,217
Recurring | Significant Other Observable Inputs (Level 2) | Reinsurance recoverable
Investments:
Reinsurance balances recoverable on paid and unpaid losses	0	0
Recurring | Significant Other Observable Inputs (Level 2) | Derivative instruments, assets
Other Assets:
Derivative instruments	8,311	2,011
Recurring | Significant Other Observable Inputs (Level 2) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	585	15,558
Recurring | Significant Unobservable Inputs (Level 3)
Investments:
Equities, at fair value	271,045	265,799
Total Investments	281,359	353,668
Cash and cash equivalents	0	0
Other Assets:
Losses and LAE	2,422,678	2,621,122
Recurring | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	10,314	87,869
Recurring | Significant Unobservable Inputs (Level 3) | Reinsurance recoverable
Investments:
Reinsurance balances recoverable on paid and unpaid losses	543,161	695,518
Recurring | Significant Unobservable Inputs (Level 3) | Derivative instruments, assets
Other Assets:
Derivative instruments	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	0	0
Recurring | Fair Value Based on NAV as Practical Expedient
Investments:
Total Investments	3,176,821	1,920,945
Cash and cash equivalents	0	0
Recurring | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	3,176,821	1,920,945
Recurring | U.S. government and agency | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	789,630	696,077
Recurring | U.S. government and agency | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | U.S. government and agency | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	789,630	696,077
Recurring | U.S. government and agency | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | U.K. government | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	114,777	161,772
Recurring | U.K. government | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | U.K. government | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	114,777	161,772
Recurring | U.K. government | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Other government | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	490,447	702,856
Recurring | Other government | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Other government | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	490,447	702,856
Recurring | Other government | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Corporate | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	5,679,909	5,448,270
Recurring | Corporate | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Corporate | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	5,679,909	5,448,270
Recurring | Corporate | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Municipal | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	161,839	140,687
Recurring | Municipal | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Municipal | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	161,839	140,687
Recurring | Municipal | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Residential mortgage-backed | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	529,239	400,914
Recurring | Residential mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Residential mortgage-backed | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	529,239	400,914
Recurring | Residential mortgage-backed | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Commercial mortgage-backed | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	843,119	813,746
Recurring | Commercial mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Commercial mortgage-backed | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	843,119	813,746
Recurring | Commercial mortgage-backed | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Asset-backed | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	613,663	670,235
Recurring | Asset-backed | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Asset-backed | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	613,663	670,235
Recurring | Asset-backed | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Funds held - directly managed | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	12,438	14,207
Recurring | Funds held - directly managed | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Funds held - directly managed | Significant Other Observable Inputs (Level 2) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	12,438	14,207
Recurring | Funds held - directly managed | Significant Unobservable Inputs (Level 3) | Short-Term Investments and Fixed Maturities
Investments:
Short-term and fixed maturity investments	0	0
Recurring | Publicly traded equity investments
Investments:
Equities, at fair value	303,932	327,875
Recurring | Publicly traded equity investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Investments:
Equities, at fair value	282,904	297,310
Recurring | Publicly traded equity investments | Significant Other Observable Inputs (Level 2)
Investments:
Equities, at fair value	21,028	30,565
Recurring | Publicly traded equity investments | Significant Unobservable Inputs (Level 3)
Investments:
Equities, at fair value	0	0
Recurring | Exchange-traded funds
Investments:
Equities, at fair value	78,182	133,047
Recurring | Exchange-traded funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Investments:
Equities, at fair value	78,182	133,047
Recurring | Exchange-traded funds | Significant Other Observable Inputs (Level 2)
Investments:
Equities, at fair value	0	0
Recurring | Exchange-traded funds | Significant Unobservable Inputs (Level 3)
Investments:
Equities, at fair value	0	0
Recurring | Private equity funds
Investments:
Equities, at fair value	271,045	265,799
Recurring | Private equity funds | Other investments
Investments:
Other investments	320,455	323,496
Recurring | Private equity funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Investments:
Equities, at fair value	0	0
Recurring | Private equity funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0	0
Recurring | Private equity funds | Significant Other Observable Inputs (Level 2)
Investments:
Equities, at fair value	0	0
Recurring | Private equity funds | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	0	0
Recurring | Private equity funds | Significant Unobservable Inputs (Level 3)
Investments:
Equities, at fair value	271,045	265,799
Recurring | Private equity funds | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	0	0
Recurring | Private equity funds | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	320,455	323,496
Recurring | Hedge funds | Other investments
Investments:
Other investments	2,087,091	1,121,904
Recurring | Hedge funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0	0
Recurring | Hedge funds | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	0	0
Recurring | Hedge funds | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	0	0
Recurring | Hedge funds | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	2,087,091	1,121,904
Recurring | Fixed income funds | Other investments
Investments:
Other investments	684,031	481,039
Recurring | Fixed income funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0	0
Recurring | Fixed income funds | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	428,645	398,143
Recurring | Fixed income funds | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	0	0
Recurring | Fixed income funds | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	255,386	82,896
Recurring | Equity funds | Other investments
Investments:
Other investments	290,129	410,149
Recurring | Equity funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0	0
Recurring | Equity funds | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	4,558	111,040
Recurring | Equity funds | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	0	0
Recurring | Equity funds | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	285,571	299,109
Recurring | CLO equities | Other investments
Investments:
Other investments	84,532	87,555
Recurring | CLO equities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0	0
Recurring | CLO equities | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	84,532	0
Recurring | CLO equities | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	0	87,555
Recurring | CLO equities | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	0	0
Recurring | CLO equity funds | Other investments
Investments:
Other investments	140,458	87,509
Recurring | CLO equity funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0	0
Recurring | CLO equity funds | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	0	0
Recurring | CLO equity funds | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	0	0
Recurring | CLO equity funds | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	140,458	87,509
Recurring | Private credit funds | Other investments
Investments:
Other investments	90,476
Recurring | Private credit funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0
Recurring | Private credit funds | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	0
Recurring | Private credit funds | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	10,000
Recurring | Private credit funds | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	80,476
Recurring | Other | Other investments
Investments:
Other investments	7,698	6,379
Recurring | Other | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Investments:
Other investments	0	0
Recurring | Other | Significant Other Observable Inputs (Level 2) | Other investments
Investments:
Other investments	0	34
Recurring | Other | Significant Unobservable Inputs (Level 3) | Other investments
Investments:
Other investments	314	314
Recurring | Other | Fair Value Based on NAV as Practical Expedient | Other investments
Investments:
Other investments	7,384	6,031
Derivatives qualifying as hedges | Recurring | Derivative instruments, assets
Other Assets:
Derivative instruments	6,785	642
Derivatives qualifying as hedges | Recurring | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	0	11,452
Derivatives qualifying as hedges | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments, assets
Other Assets:
Derivative instruments	0	0
Derivatives qualifying as hedges | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	0	0
Derivatives qualifying as hedges | Recurring | Significant Other Observable Inputs (Level 2) | Derivative instruments, assets
Other Assets:
Derivative instruments	6,785	642
Derivatives qualifying as hedges | Recurring | Significant Other Observable Inputs (Level 2) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	0	11,452
Derivatives qualifying as hedges | Recurring | Significant Unobservable Inputs (Level 3) | Derivative instruments, assets
Other Assets:
Derivative instruments	0	0
Derivatives qualifying as hedges | Recurring | Significant Unobservable Inputs (Level 3) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	0	0
Derivatives not qualifying as hedges | Recurring | Derivative instruments, assets
Other Assets:
Derivative instruments	1,526	1,369
Derivatives not qualifying as hedges | Recurring | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	585	4,106
Derivatives not qualifying as hedges | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments, assets
Other Assets:
Derivative instruments	0	0
Derivatives not qualifying as hedges | Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	0	0
Derivatives not qualifying as hedges | Recurring | Significant Other Observable Inputs (Level 2) | Derivative instruments, assets
Other Assets:
Derivative instruments	1,526	1,369
Derivatives not qualifying as hedges | Recurring | Significant Other Observable Inputs (Level 2) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	585	4,106
Derivatives not qualifying as hedges | Recurring | Significant Unobservable Inputs (Level 3) | Derivative instruments, assets
Other Assets:
Derivative instruments	0	0
Derivatives not qualifying as hedges | Recurring | Significant Unobservable Inputs (Level 3) | Derivative instruments, liabilities
Other Liabilities:
Derivative instruments	$ 0	$ 0

Fair Value Measurements - Inves

Fair Value Measurements - Investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Reinsurance balances recoverable
Beginning fair value	$ 271,314	$ 312,163	$ 353,668	$ 321,973
Purchases	10,000	26,392	48,484	38,477
Sales	0	(2,964)	(539)	(6,943)
Total realized and unrealized gains	45	(8,364)	(36,514)	(7,717)
Transfer into Level 3 from Level 2		277	0	27,923
Transfer out of Level 3 into Level 2	0	(10,284)	(83,740)	(56,493)
Ending fair value	281,359	317,220	281,359	317,220
Corporate
Reinsurance balances recoverable
Beginning fair value		5,006		37,386
Purchases		82		172
Sales		(116)		(3,157)
Total realized and unrealized gains		(103)		114
Transfer into Level 3 from Level 2		277		3,535
Transfer out of Level 3 into Level 2		(2,865)		(35,769)
Ending fair value		2,281		2,281
Residential mortgage-backed
Reinsurance balances recoverable
Beginning fair value		102		0
Purchases		0		0
Sales		0		0
Total realized and unrealized gains		(1)		(1)
Transfer into Level 3 from Level 2		0		102
Transfer out of Level 3 into Level 2		(101)		(101)
Ending fair value		0		0
Commercial mortgage-backed
Reinsurance balances recoverable
Beginning fair value		1,370		7,389
Purchases		0		0
Sales		(176)		(784)
Total realized and unrealized gains		148		65
Transfer into Level 3 from Level 2		0		1,515
Transfer out of Level 3 into Level 2		(1,340)		(8,183)
Ending fair value		2		2
Asset-backed
Reinsurance balances recoverable
Beginning fair value		25,839		9,121
Purchases		0		0
Sales		(295)		(625)
Total realized and unrealized gains		(743)		(4)
Transfer into Level 3 from Level 2		0		22,771
Transfer out of Level 3 into Level 2		(5,978)		(12,440)
Ending fair value		18,823		18,823
Privately-held Equities
Reinsurance balances recoverable
Beginning fair value	271,000	229,394	265,799	228,710
Purchases	0	3,691	1,392	3,691
Sales	0	(2,016)	0	(2,016)
Total realized and unrealized gains	45	(2,378)	3,854	(1,694)
Transfer into Level 3 from Level 2		0	0	0
Transfer out of Level 3 into Level 2	0	0	0	0
Ending fair value	271,045	228,691	271,045	228,691
Other Investments
Reinsurance balances recoverable
Beginning fair value	314	50,452	87,869	39,367
Purchases	10,000	22,619	47,092	34,614
Sales	0	(361)	(539)	(361)
Total realized and unrealized gains	0	(5,287)	(40,368)	(6,197)
Transfer into Level 3 from Level 2		0	0	0
Transfer out of Level 3 into Level 2	0	0	(83,740)	0
Ending fair value	$ 10,314	$ 67,423	$ 10,314	$ 67,423

Fair Value Measurements - Valua

Fair Value Measurements - Valuation Techniques (Details) - Private equity funds - Level 3 $ in Millions	Sep. 30, 2020USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments	$ 271
Transactional value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments	245.4
Cost as approximation of fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments	$ 25.6
Minimum | Transactional value | Measurement Input, Quoted Price [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments, measurement input	13.50
Maximum | Transactional value | Measurement Input, Quoted Price [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments, measurement input	13.85

Fair Value Measurements - Insur

Fair Value Measurements - Insurance Contracts (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Reinsurance balances recoverable
Beginning fair value	$ 271,314	$ 312,163	$ 353,668	$ 321,973
Assumed business	10,000	26,392	48,484	38,477
Incurred losses and LAE:
Change in fair value	45	(8,364)	(36,514)	(7,717)
Ending fair value	281,359	317,220	281,359	317,220
Net
Beginning fair value	1,783,155	2,029,197	1,925,604	2,134,464
Assumed business	182,498	0	182,498	0
Incurred losses and LAE:
Reduction in estimates of ultimate losses	(82,297)	(9,740)	(109,689)	(24,401)
Reduction in unallocated LAE	(4,641)	(6,724)	(14,353)	(15,076)
Change in fair value	21,042	41,374	96,848	135,377
Total incurred losses and LAE	(65,896)	24,910	(27,194)	95,900
Paid losses	(75,553)	(78,838)	(180,560)	(250,128)
Effect of exchange rate movements	55,313	(48,529)	(20,831)	(53,496)
Ending fair value	1,879,517	1,926,740	1,879,517	1,926,740
Liability for losses and LAE
Liability for losses and LAE
Beginning fair value	2,454,539	2,772,501	2,621,122	2,874,055
Assumed business	1,526	0	1,526	0
Incurred losses and LAE:
Reduction in estimates of ultimate losses	(25,595)	(7,386)	(61,109)	(20,342)
Reduction in unallocated LAE	(4,641)	(6,724)	(14,353)	(15,076)
Change in fair value	19,092	57,743	130,075	189,422
Total incurred losses and LAE	(11,144)	43,633	54,613	154,004
Paid losses	(86,745)	(100,654)	(230,187)	(308,267)
Effect of exchange rate movements	64,502	(56,836)	(24,396)	(61,148)
Ending fair value	2,422,678	2,658,644	2,422,678	2,658,644
Reinsurance balances recoverable
Reinsurance balances recoverable
Beginning fair value	671,384	743,304	695,518	739,591
Assumed business	(180,972)	0	(180,972)	0
Incurred losses and LAE:
Reduction in estimates of ultimate losses	56,702	2,354	48,580	4,059
Reduction in unallocated LAE	0	0	0	0
Change in fair value	(1,950)	16,369	33,227	54,045
Total incurred losses and LAE	54,752	18,723	81,807	58,104
Paid losses	(11,192)	(21,816)	(49,627)	(58,139)
Effect of exchange rate movements	9,189	(8,307)	(3,565)	(7,652)
Ending fair value	543,161	731,904	543,161	731,904
Duration
Incurred losses and LAE:
Change in fair value	11,767	3,850	19,617	18,736
Corporate bond yield
Incurred losses and LAE:
Change in fair value	$ 9,275	$ 37,524	75,524	116,641
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 - Obser

Fair Value Measurements - Observable and Unobservable Inputs (Details) - Internal Model - Recurring	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Liability for losses and LAE
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 11 months 1 day	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	7 years 8 months 15 days	8 years 8 months 4 days
Measurement Input, Entity Credit Risk | Liability for losses and LAE
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 - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Aug. 26, 2020	Dec. 31, 2019	May 28, 2019	Mar. 10, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assumed business	$ 182,498	$ 0	$ 182,498	$ 0
Debt, amortized cost	1,447,908		1,447,908			$ 1,191,207
Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, amortized cost	$ 843,095		$ 843,095			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%					4.50%
Debt, amortized cost	$ 349,155		$ 349,155			348,616
Debt, fair value	$ 363,200		$ 363,200
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%				4.95%
Debt, amortized cost	$ 493,940		$ 493,940			493,600
Debt, fair value	$ 556,800		$ 556,800
5.75% Junior Subordinated Notes due 2040 | Junior Subordinated Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	5.75%		5.75%		5.75%
Debt, amortized cost	$ 344,813		$ 344,813			$ 0
Debt, fair value	$ 357,700		$ 357,700

Premiums Written and Earned - S

Premiums Written and Earned - Schedule of Net Premiums Written and Earned (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Effects of Reinsurance [Line Items]
Gross, premiums written	$ 111,477	$ 157,135	$ 460,630	$ 483,912
Ceded, premiums written	(17,918)	(43,641)	(91,836)	(93,175)
Net, premiums written	93,559	113,494	368,794	390,737
Gross, premiums earned	198,634	231,763	575,385	726,476
Ceded premium earned	(36,910)	(55,961)	(111,439)	(107,765)
Net, premiums earned	161,724	175,802	463,946	618,711
Operating Segments | Non-life Run-off
Effects of Reinsurance [Line Items]
Gross, premiums written	3,535	301	1,707	(24,785)
Ceded, premiums written	(111)	(4,109)	690	(1,610)
Net, premiums written	3,424	(3,808)	2,397	(26,395)
Gross, premiums earned	20,426	27,190	52,899	166,707
Ceded premium earned	(2,950)	(10,353)	(8,876)	(24,726)
Net, premiums earned	17,476	16,837	44,023	141,981
Operating Segments | Atrium
Effects of Reinsurance [Line Items]
Gross, premiums written	49,083	48,746	155,551	146,519
Ceded, premiums written	(2,580)	(4,961)	(19,458)	(19,273)
Net, premiums written	46,503	43,785	136,093	127,246
Gross, premiums earned	48,690	48,340	144,675	133,610
Ceded premium earned	(6,264)	(5,427)	(16,492)	(13,745)
Net, premiums earned	42,426	42,913	128,183	119,865
Operating Segments | StarStone
Effects of Reinsurance [Line Items]
Gross, premiums written	58,566	110,586	300,135	363,352
Ceded, premiums written	(15,228)	(34,566)	(73,069)	(72,269)
Net, premiums written	43,338	76,020	227,066	291,083
Gross, premiums earned	123,813	151,895	362,638	409,135
Ceded premium earned	(27,697)	(40,146)	(86,072)	(69,142)
Net, premiums earned	96,116	111,749	276,566	339,993
Other
Effects of Reinsurance [Line Items]
Gross, premiums written	293	(2,498)	3,237	(1,174)
Ceded, premiums written	1	(5)	1	(23)
Net, premiums written	294	(2,503)	3,238	(1,197)
Gross, premiums earned	5,705	4,338	15,173	17,024
Ceded premium earned	1	(35)	1	(152)
Net, premiums earned	$ 5,706	$ 4,303	$ 15,174	$ 16,872

Premiums Written and Earned - N

Premiums Written and Earned - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Gross, premiums written	$ 111,477	$ 157,135	$ 460,630	$ 483,912
Increase (decrease) in gross premiums written	(45,700)		(23,300)
Starstone
Segment Reporting Information [Line Items]
Increase (decrease) in gross premiums written	(52,000)		(63,200)
Non-life Run-off
Segment Reporting Information [Line Items]
Increase (decrease) in gross premiums written	$ 3,200		26,500
Atrium
Segment Reporting Information [Line Items]
Increase (decrease) in gross premiums written			$ 9,000

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Goodwill
Balance as of December 31, 2019			$ 109,807
Impairment losses (StarStone International)			(8,000)
Reclassification to assets held-for-sale (Atrium)			(38,848)
Balance as of September 30, 2020	$ 62,959		62,959
Intangible assets with a definite life
Balance as of December 31, 2019			14,630
Impairment losses (StarStone International)			0
Amortization	(508)	$ (546)	(1,524)	$ (1,676)
Reclassification to assets held-for-sale (Atrium)			(13,106)
Balance as of September 30, 2020	0		0
Intangible  assets with an indefinite life
Balance as of December 31, 2019			67,131
Impairment losses (StarStone International)			(4,000)
Reclassification to assets held-for-sale (Atrium)			(63,131)
Balance as of September 30, 2020	0		0
Intangible Assets [Roll Forward]
Balance as of December 31, 2019			81,761
Impairment losses (StarStone International)			(4,000)
Reclassification to assets held-for-sale (Atrium)			(76,237)
Balance as of September 30, 2020	0		0
Goodwill and Intangible Assets [Roll Forward]
Balance as of December 31, 2019			191,568
Impairment losses (StarStone International)			(12,000)
Reclassification to assets held-for-sale (Atrium)			(115,085)
Balance as of September 30, 2020	$ 62,959		$ 62,959

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Goodwill (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)
Goodwill
Balance as of December 31, 2019		$ 109,807,000
Impairment losses (StarStone International)		(8,000,000)
Reclassification to assets held-for-sale (Atrium)		(38,848,000)
Balance as of September 30, 2020:
Goodwill	$ 70,959,000	70,959,000
Accumulated impairment losses	(8,000,000)	(8,000,000)
Balance as of September 30, 2020	62,959,000	62,959,000
Non-life Run-off
Goodwill
Balance as of December 31, 2019		62,959,000
Impairment losses (StarStone International)		0
Reclassification to assets held-for-sale (Atrium)		0
Balance as of September 30, 2020:
Goodwill	62,959,000	62,959,000
Accumulated impairment losses	0	0
Balance as of September 30, 2020	62,959,000	62,959,000
Atrium
Goodwill
Balance as of December 31, 2019		38,848,000
Impairment losses (StarStone International)		0
Reclassification to assets held-for-sale (Atrium)		(38,848,000)
Balance as of September 30, 2020:
Goodwill	0	0
Accumulated impairment losses	0	0
Balance as of September 30, 2020	0	0
StarStone
Goodwill
Balance as of December 31, 2019		8,000,000
Impairment losses (StarStone International)	0	(8,000,000)
Reclassification to assets held-for-sale (Atrium)		0
Balance as of September 30, 2020:
Goodwill	8,000,000	8,000,000
Accumulated impairment losses	(8,000,000)	(8,000,000)
Balance as of September 30, 2020	$ 0	$ 0

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Goodwill [Line Items]
Impairment loss		$ (8,000,000)
Indefinite-lived intangible asset, impairment loss		(4,000,000)
StarStone
Goodwill [Line Items]
Impairment loss	$ 0	(8,000,000)
StarStone | Lloyd’s syndicate capacity
Goodwill [Line Items]
Indefinite-lived intangible asset, impairment loss	$ 0	$ (4,000,000)

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Intangible assets with a definite life:
Net Carrying Value	$ 0	$ 14,630
Intangible assets with an indefinite life:
Net carrying value	0	67,131
Gross carrying value	4,000	94,131
Accumulated amortization and impairment losses	(4,000)	(12,370)
Net carrying value	0	81,761
Atrium
Intangible assets with a definite life:
Accumulated Amortization	0	(12,370)
Intangible assets with an indefinite life:
Gross carrying value	0	90,131
Net carrying value	0	77,761
Atrium | Lloyd’s syndicate capacity
Intangible assets with an indefinite life:
Gross carrying value	0	33,031
Net carrying value	0	33,031
Atrium | Management contract
Intangible assets with an indefinite life:
Gross carrying value	0	30,100
Net carrying value	0	30,100
StarStone | Lloyd’s syndicate capacity
Intangible assets with an indefinite life:
Gross carrying value	4,000	4,000
Accumulated Impairment	(4,000)	0
Net carrying value	0	4,000
Distribution channel | Atrium
Intangible assets with a definite life:
Gross Carrying Value	0	20,000
Accumulated Amortization	0	(8,111)
Net Carrying Value	0	11,889
Brand | Atrium
Intangible assets with a definite life:
Gross Carrying Value	0	7,000
Accumulated Amortization	0	(4,259)
Net Carrying Value	$ 0	$ 2,741

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets - Intangible Asset Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible asset amortization	$ 508	$ 546	$ 1,524	$ 1,676

Debt Obligations and Credit F_3

Debt Obligations and Credit Facilities - Amounts Outstanding and Accrued Interest (Details) - USD ($)	Dec. 27, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Aug. 26, 2020	Dec. 31, 2019	May 28, 2019	Mar. 10, 2017
Debt Instrument [Line Items]
Debt, amortized cost		$ 1,447,908,000		$ 1,447,908,000			$ 1,191,207,000
Interest expense on debt obligations		14,652,000	$ 14,623,000	41,522,000	$ 38,157,000
Amortization of debt issuance costs		351,000	311,000	914,000	539,000
Funds withheld balances and other		0	16,000	0	326,000
Total interest expense		15,003,000	$ 14,950,000	42,436,000	$ 39,022,000
Senior Notes
Debt Instrument [Line Items]
Debt, amortized cost		$ 843,095,000		$ 843,095,000			842,216,000
Senior Notes | 4.50% Senior Notes due 2022
Debt Instrument [Line Items]
Stated interest rate		4.50%		4.50%					4.50%
Term				5 years
Debt, amortized cost		$ 349,155,000		$ 349,155,000			348,616,000
Senior Notes | 4.95% Senior Notes due 2029
Debt Instrument [Line Items]
Stated interest rate		4.95%		4.95%				4.95%
Term				10 years
Debt, amortized cost		$ 493,940,000		$ 493,940,000			493,600,000
Junior Subordinated Debt | 5.75% Junior Subordinated Notes due 2040
Debt Instrument [Line Items]
Stated interest rate		5.75%		5.75%		5.75%
Term				20 years
Debt, amortized cost		$ 344,813,000		$ 344,813,000			0
Line of Credit | EGL Revolving Credit Facility
Debt Instrument [Line Items]
Term				5 years
Debt, amortized cost		260,000,000		$ 260,000,000			0
Line of Credit | 2018 EGL Term Loan Facility
Debt Instrument [Line Items]
Term	3 years			3 years
Debt, amortized cost		$ 0		$ 0			$ 348,991,000

Debt Obligations and Credit F_4

Debt Obligations and Credit Facilities - Additional Information (Details) - USD ($)	Nov. 05, 2020	Aug. 26, 2020	May 28, 2019	Dec. 27, 2018	Mar. 10, 2017	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Sep. 01, 2040	Nov. 06, 2020	Aug. 04, 2020	Dec. 06, 2019	Aug. 16, 2018
Line of Credit Facility [Line Items]
Receipt of loans							$ 858,788,000	$ 1,070,808,000
Repayment of loans							604,000,000	$ 722,574,000
Debt outstanding						$ 1,447,908,000	1,447,908,000		$ 1,191,207,000
Cash and investments						547,000,000	547,000,000		639,300,000
Maiden Facility Agreement
Line of Credit Facility [Line Items]
Proceeds from credit facility agreement									456,800,000
Senior Notes
Line of Credit Facility [Line Items]
Debt outstanding						$ 843,095,000	$ 843,095,000		842,216,000
Senior Notes | 4.50% Senior Notes due 2022
Line of Credit Facility [Line Items]
Stated interest rate					4.50%	4.50%	4.50%
Outstanding amount of debt					$ 350,000,000
Payments of debt issuance costs					$ 2,900,000
Unamortized costs						$ 800,000	$ 800,000		1,400,000
Term of debt							5 years
Debt outstanding						$ 349,155,000	$ 349,155,000		348,616,000
Senior Notes | 4.95% Senior Notes due 2029
Line of Credit Facility [Line Items]
Stated interest rate			4.95%			4.95%	4.95%
Outstanding amount of debt			$ 500,000,000
Payments of debt issuance costs			$ 6,800,000
Unamortized costs						$ 6,100,000	$ 6,100,000		6,400,000
Term of debt							10 years
Debt outstanding						$ 493,940,000	$ 493,940,000		493,600,000
Junior Subordinated Debt | 5.75% Junior Subordinated Notes due 2040
Line of Credit Facility [Line Items]
Stated interest rate		5.75%				5.75%	5.75%
Outstanding amount of debt		$ 350,000,000
Unamortized costs						$ 5,200,000	$ 5,200,000
Receipt of loans		344,800,000
Term of debt							20 years
Debt outstanding						344,813,000	$ 344,813,000		0
Junior Subordinated Debt | 5.75% Junior Subordinated Notes due 2040 | Treasury Rate | Scenario, Forecast
Line of Credit Facility [Line Items]
Basis spread on interest rate										5.468%
Line of Credit | 2018 EGL Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity						600,000,000	600,000,000
Line of credit facility, remaining borrowing capacity						340,000,000	$ 340,000,000
Optional increase in borrowing capacity														$ 400,000,000
Term of debt							5 years
Debt outstanding						260,000,000	$ 260,000,000		0
Line of Credit | 2018 EGL Revolving Credit Facility | Subsequent Event
Line of Credit Facility [Line Items]
Line of credit facility, remaining borrowing capacity											$ 340,000,000
Line of Credit | 2018 EGL Term Loan Facility
Line of Credit Facility [Line Items]
Payments of debt issuance costs				$ 1,500,000
Unamortized costs						0	$ 0		1,000,000
Repayment of loans		$ 350,000,000				350,000,000			150,000,000
Maximum borrowing capacity				$ 500,000,000
Term of debt				3 years			3 years
Debt outstanding						0	$ 0		348,991,000
Line of Credit | FAL Facility
Line of Credit Facility [Line Items]
Higher borrowing capacity option						400,000,000	400,000,000
Letters of Credit | Line of Credit | FAL Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity						375,000,000	375,000,000
Line of credit facility, remaining borrowing capacity						252,000,000	252,000,000		252,000,000
Optional increase in borrowing capacity						25,000,000	25,000,000
Letters of Credit | Line of Credit | FAL Facility | Subsequent Event
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 275,000,000
Optional increase in borrowing capacity	$ 75,000,000
Term extension	2 years
Letters of Credit | Line of Credit | 2018 Facility Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity													$ 120,000,000
Optional increase in borrowing capacity													$ 60,000,000
Letters of credit						120,000,000	120,000,000		115,300,000
Letters of Credit | Line of Credit | Maiden Facility Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity									760,000,000			$ 800,000,000
Optional increase in borrowing capacity												40,000,000
Letters of credit						$ 619,800,000	$ 619,800,000		$ 608,000,000
Letters of Credit | Line of Credit | 2020 Letter Of Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity												65,000,000
Letters of credit												$ 61,000,000

Noncontrolling Interests - Addi

Noncontrolling Interests - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Noncontrolling Interest [Line Items]
Net earnings (losses) attributable to RNCI	$ 20,997	$ (190)	$ (31,102)	$ (5,651)
Change in redemption value of RNCI	(11,431)	$ (622)	(38,059)	$ (6,607)
Noncontrolling interest	$ 14,468		$ 14,468		$ 14,168
North Bay | Trident
Noncontrolling Interest [Line Items]
Interest owned by an entity (percent)	39.30%		39.30%
North Bay | Dowling
Noncontrolling Interest [Line Items]
Interest owned by an entity (percent)	1.70%		1.70%
North Bay | Subsidiaries | Trident
Noncontrolling Interest [Line Items]
Interest owned by an entity (percent)	39.30%		39.30%		39.30%
North Bay | Subsidiaries | Dowling
Noncontrolling Interest [Line Items]
Interest owned by an entity (percent)	1.70%		1.70%		1.70%

Noncontrolling Interests - Carr

Noncontrolling Interests - Carrying Amount of Equity Attributable to Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Increase (Decrease) in Redeemable Noncontrolling Interest [Roll Forward]
Balance at beginning of period	$ 366,533	$ 438,791	$ 435,696	$ 438,791	$ 458,543	$ 458,543
Dividends paid	0		0	0	(11,556)
Net earnings (losses) attributable to RNCI	20,997		(190)	(31,102)	(5,651)
Accumulated other comprehensive earnings attributable to RNCI	1,220		(97)	7,593	58
Foreign currency translation adjustments	(588)		0	(753)	0
Change in redemption value of RNCI	(11,431)		(622)	(38,059)	(6,607)
Cumulative effect of change in accounting principle attributable to RNCI	0		0	261	0
Balance at end of period	$ 376,731		$ 434,787	$ 376,731	$ 434,787	$ 438,791
Accounting standards update		us-gaap:AccountingStandardsUpdate201613Member				us-gaap:AccountingStandardsUpdate201613Member

Share Capital (Details)

Share Capital (Details) - USD ($)	Nov. 05, 2020	Aug. 05, 2020	May 05, 2020	Feb. 04, 2020	Jan. 21, 2020	Nov. 06, 2020	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Mar. 09, 2020
Class of Stock [Line Items]
Total dividends paid								$ 26,775,000	$ 26,989,000
Repurchase authorized amount										$ 150,000,000
Shares repurchased (in shares)							174,464
Average price per share repurchased (in dollars per share)							$ 145.53
Shares repurchased, value							$ 25,400,000	25,390,000	$ 0
Remaining repurchase amount							$ 124,600,000	$ 124,600,000
Series D Preferred Stock
Class of Stock [Line Items]
Declared cash dividends (in dollars per share)		$ 437.50	$ 437.50	$ 437.50
Declared cash dividends (in dollars per depositary share)		$ 0.43750	$ 0.43750	$ 0.43750
Total dividends paid		$ 7,000,000	$ 7,000,000	$ 7,000,000
Series E Preferred Stock
Class of Stock [Line Items]
Declared cash dividends (in dollars per share)		$ 437.50	$ 437.50	$ 437.50
Declared cash dividends (in dollars per depositary share)		$ 0.43750	$ 0.43750	$ 0.43750
Total dividends paid		$ 1,925,000	$ 1,925,000	$ 1,925,000
Subsequent Event
Class of Stock [Line Items]
Shares repurchased (in shares)						3,816
Shares repurchased, value						$ 600,000
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)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net earnings from continuing operations	$ 612,636	$ 113,074	$ 896,267	$ 701,234
Net earnings from discontinued operations	2,377	4,669	478	7,102
NET EARNINGS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$ 615,013	$ 117,743	$ 896,745	$ 708,336
Denominator:
Weighted-average ordinary shares outstanding — basic (in shares)	21,578,106	21,488,216	21,564,447	21,476,586
Effect of dilutive securities:
Share-based compensation plans (in shares)	143,581	169,162	180,437	204,288
Warrants (in shares)	57,042	63,119	54,743	60,625
Weighted-average ordinary shares outstanding — diluted (in shares)	21,778,729	21,720,497	21,799,627	21,741,499
Basic:
Net earnings from continuing operations (in dollars per share)	$ 28.39	$ 5.26	$ 41.56	$ 32.65
Net earnings from discontinued operations (in dollars per share)	0.11	0.22	0.02	0.33
Net earnings per ordinary share (in dollars per share)	28.50	5.48	41.58	32.98
Diluted:
Net earnings from continuing operations (in dollars per share)	28.13	5.21	41.12	32.25
Net earnings from discontinued operations (in dollars per share)	0.11	0.21	0.02	0.33
Net earnings per ordinary share (in dollars per share)	$ 28.24	$ 5.42	$ 41.14	$ 32.58

Share-Based Compensation - Comp

Share-Based Compensation - Compensation Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 13,258	$ 8,805	$ 22,296	$ 27,296
Restricted shares and restricted share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	2,251	1,778	6,180	4,910
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	5,698	5,678	10,886	18,133
Cash-settled stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	3,705	102	230	(109)
Employee share purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	110	102	318	309
Joint share ownership plan expense | Employee share purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	1,146	0	3,151	0
Northshore incentive plan | Incentive plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	209	1,029	656	3,061
StarStone incentive plan | Incentive plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	0	0	(223)	0
Deferred compensation and ordinary share plan for non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred compensation and ordinary share plan for non-employee directors	$ 139	$ 116	$ 1,098	$ 992

Income Taxation (Details)

Income Taxation (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Effective tax rate expense (benefit)	2.10%	10.20%	2.80%	3.40%
Statutory rate			0.00%
Unrecognized tax benefits	$ 0		$ 0		$ 0

Related Party Transactions - St

Related Party Transactions - Stone Point Capital LLC (Details) $ in Thousands	Dec. 31, 2020director	Oct. 01, 2019USD ($)	Apr. 01, 2019USD ($)	Oct. 01, 2018USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Jul. 31, 2012shares	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Mar. 31, 2021	Dec. 31, 2019USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)	Nov. 06, 2013general_partner
Related Party Transaction [Line Items]
Assumed business					$ 280,497		$ 445,000		$ 1,705,970	$ 1,110,881
Adverse development cover		$ 59,000
Redeemable noncontrolling interest					376,731	$ 366,533	434,787		376,731	434,787		$ 438,791	$ 435,696	$ 458,543
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value					3,161,647				3,161,647			1,666,387
Equities, at fair value					653,159				653,159			726,721
Other investments, at fair value					3,704,870				3,704,870			2,518,031
Total investments					14,109,885				14,109,885			12,619,793
Cash and cash equivalents					640,601		557,677		640,601	557,677		624,472
Other assets					677,797				677,797			699,081
Other liabilities					478,888				478,888			444,818
Related Party, Consolidated Statement of Earnings [Abstract]
Net investment income					72,130		81,502		241,287	231,424
Net realized and unrealized gains					500,005		145,060		838,552	858,489
NET EARNINGS					$ 645,850		126,559		$ 892,718	730,355
Scenario, Forecast
Related Party Transaction [Line Items]
Number of newly elected board of directors | director	5
North Bay
Related Party Transaction [Line Items]
Ownership percentage in noncontrolling interest by parent					59.00%				59.00%
SSHL
Related Party Transaction [Line Items]
Ownership percentage in noncontrolling interest by parent					59.00%				59.00%
Northshore | Scenario, Forecast
Related Party Transaction [Line Items]
Percentage of shares owned in order to designate member of board of directors	50.00%
Right to designate board of directors if 50% or more of shares owned | director	1
Common shares subject to transfer restriction, term	18 months
Short-term investments, AFS, at fair value
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value					$ 278,175				$ 278,175			128,335
Trading, at fair value					7,133				7,133			51,490
Fixed Maturities
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value					2,883,472				2,883,472			1,538,052
Trading, at fair value					4,999,642				4,999,642			6,143,335
Hedge funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					2,087,091				2,087,091			1,121,904
Fixed income funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					684,031				684,031			481,039
Private equity funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					320,455				320,455			323,496
CLO equities
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					84,532				84,532			87,555
CLO equity funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					140,458				140,458			87,509
SSHL | Scenario, Forecast
Related Party Transaction [Line Items]
Right to designate board of directors | director	3
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					361,026				361,026			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					94,353				94,353			121,794
Total investments					1,018,530				1,018,530			1,142,446
Cash and cash equivalents					21,293				21,293			54,080
Other assets					6,327				6,327			10
Other liabilities					162				162			4,710
Net investment					1,045,988				1,045,988			1,191,826
Related Party, Consolidated Statement of Earnings [Abstract]
Net investment income					2,312		2,257		11,189	5,009
Net realized and unrealized gains					35,925		(3,442)		(36,862)	26,305
NET EARNINGS					38,237		$ (1,185)		(25,673)	$ 31,314
StonePoint And Affiliated Entities | Short-term investments, AFS, at fair value
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value					0				0			1,431
StonePoint And Affiliated Entities | Fixed Maturities
Related Party, Consolidated Balance Sheet [Abstract]
Available-for-sale, at fair value					93,779				93,779			160,303
Trading, at fair value					219,435				219,435			269,131
StonePoint And Affiliated Entities | Hedge funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					18,510				18,510			18,993
StonePoint And Affiliated Entities | Fixed income funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					335,033				335,033			381,449
StonePoint And Affiliated Entities | Private equity funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					32,050				32,050			34,858
StonePoint And Affiliated Entities | CLO equities
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					33,358				33,358			32,560
StonePoint And Affiliated Entities | CLO equity funds
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					140,458				140,458			87,509
StonePoint And Affiliated Entities | Private Debt
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					27,079				27,079			16,312
StonePoint And Affiliated Entities | Real estate fund
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value					$ 24,475				$ 24,475			$ 18,106
Stone Point | Affiliated Entity
Related Party Transaction [Line Items]
Ownership percentage					8.80%				8.80%
North Bay Shareholders | North Bay
Related Party Transaction [Line Items]
Payments to acquire investments			$ 48,000	$ 135,000
Trident | North Bay
Related Party Transaction [Line Items]
Interest owned by an entity (percent)					39.30%				39.30%
Trident | SSHL
Related Party Transaction [Line Items]
Interest owned by an entity (percent)					39.30%				39.30%
Trident | Northshore | Scenario, Forecast
Related Party Transaction [Line Items]
Interest owned by an entity (percent)											80.00%
Trident | SSHL | Scenario, Forecast
Related Party Transaction [Line Items]
Right to designate board of directors | director	2
Trident | North Bay
Related Party Transaction [Line Items]
Payments to acquire investments				$ 53,100
Dowling | North Bay
Related Party Transaction [Line Items]
Interest owned by an entity (percent)					1.70%				1.70%
Dowling | SSHL
Related Party Transaction [Line Items]
Interest owned by an entity (percent)					1.70%				1.70%
Dowling | Northshore | Scenario, Forecast
Related Party Transaction [Line Items]
Interest owned by an entity (percent)											1.60%
Mitchell International | Affiliated Entity
Related Party, Consolidated Balance Sheet [Abstract]
Other investments, at fair value														$ 25,000
Sound Point Capital | Affiliated Entity | Senior Secured Term Loan Facility
Related Party Transaction [Line Items]
Note receivable						$ 10,000
Term loan facility, term						2 years

Related Party Transactions - Hi

Related Party Transactions - Hillhouse (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Other investments	$ 3,704,870	$ 2,518,031
Ownership percentage	47.40%	47.40%
Hillhouse Affiliates | Affiliated Entity
Related Party Transaction [Line Items]
Ownership percentage	9.40%
Economic interest percentage	16.60%
Hillhouse
Related Party Transaction [Line Items]
Other investments	$ 2,149,746	$ 1,151,601
Hillhouse | Affiliated Entity
Related Party Transaction [Line Items]
Other investments	309,541	155,377
Increase in investments	300,000
Fees incurred	263,300
Hillhouse | Hillhouse Affiliates | Affiliated Entity
Related Party Transaction [Line Items]
Other investments	653,040	327,799
InRe Fund | Hillhouse | Affiliated Entity
Related Party Transaction [Line Items]
Other investments	1,843,532	918,633
Other funds | Hillhouse | Affiliated Entity
Related Party Transaction [Line Items]
Other investments	$ 306,214	$ 232,968
Fixed Income Securities | Hillhouse InRe Fund, L.P. | Affiliated Entity
Related Party Transaction [Line Items]
Other investments, percentage of funds	(1.00%)
North American Equities | Hillhouse InRe Fund, L.P. | Affiliated Entity
Related Party Transaction [Line Items]
Other investments, percentage of funds	22.00%
International Equities | Hillhouse InRe Fund, L.P. | Affiliated Entity
Related Party Transaction [Line Items]
Other investments, percentage of funds	49.00%
Financing, Derivatives And Other Items | Hillhouse InRe Fund, L.P. | Affiliated Entity
Related Party Transaction [Line Items]
Other investments, percentage of funds	30.00%

Related Party Transactions - Mo

Related Party Transactions - Monument Re (Details) $ in Thousands, € in Millions	3 Months Ended	9 Months Ended		39 Months Ended	48 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2020USD ($)	May 31, 2019USD ($)	May 31, 2019EUR (€)
Related Party Transaction [Line Items]
Contributed amount of common and preferred shares		$ 33,000	$ 38,403
Ownership percentage	47.40%	47.40%		47.40%	47.40%
Carrying value of previously held equity method investment prior to the close of the transaction	$ 516,795	$ 516,795		$ 326,277	$ 516,795
Monument Re (1)
Related Party Transaction [Line Items]
Contributed amount of common and preferred shares				$ 26,600	$ 59,600
Common shares, ownership percentage	20.00%	20.00%			20.00%
Ownership percentage	23.00%	23.00%		23.50%	23.00%
Carrying value of previously held equity method investment prior to the close of the transaction	$ 161,994	$ 161,994		$ 60,598	$ 161,994
Fee income (less than)	$ 100	$ 100
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 - Cl

Related Party Transactions - Clear Spring (Details) - USD ($) $ in Thousands	Jan. 01, 2017	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Capitalized amount of investment	$ 56,000
Ownership percentage		47.40%		47.40%			47.40%
Carrying value of previously held equity method investment prior to the close of the transaction		$ 516,795		$ 516,795			$ 326,277
Balances under StarStone ceding quota share included, in assets or liabilities held-for-sale:
Reinsurance balances recoverable		1,881,656		1,881,656			2,181,134
Losses and LAE
Losses and LAE		10,300,884	$ 9,516,646	10,300,884	$ 9,516,646	$ 10,593,436	9,868,404	$ 9,354,891	$ 9,048,796
Unearned reinsurance premiums		335,336		335,336			533,692
Funds held		657,490		657,490			475,732
Transactions under StarStone ceding quota share, included in net earnings (loss) from discontinued operations:
Acquisition costs		(37,708)	(33,310)	(132,818)	(162,192)
Transactions under assuming quota share:
Net incurred losses and LAE		109,686	163,258	339,678	566,111
Net earnings		645,850	126,559	892,718	730,355
Clear Spring
Related Party Transaction [Line Items]
Percentage of business reinsured	25.00%
Losses and LAE
Losses and LAE		3,995		3,995			6,135
Unearned reinsurance premiums		0		0			13
Funds held		$ 7,468		$ 7,468			8,611
Clear Spring | Equity Method Investee
Related Party Transaction [Line Items]
Ownership percentage		20.00%		20.00%
Clear Spring | Affiliated Entity
Transactions under StarStone ceding quota share, included in net earnings (loss) from discontinued operations:
Acquisition costs		$ 4	(88)	$ 11	(79)
Transactions under assuming quota share:
Premium earned		(15)	887	(15)	3,326
Net incurred losses and LAE		132	(576)	1,014	(2,013)
Net earnings		(361)	(2,019)	(787)	(3,714)
Starstone | Clear Spring
Related Party Transaction [Line Items]
Carrying value of previously held equity method investment prior to the close of the transaction		10,944		10,944			10,645
Percentage of business reinsured	33.30%
Starstone | Clear Spring | Equity Method Investee
Balances under StarStone ceding quota share included, in assets or liabilities held-for-sale:
Reinsurance balances recoverable		20,998		20,998			22,812
Prepaid insurance premiums		0		0			51
Ceded payable		3,551		3,551			3,616
Ceded acquisition costs		0		0			$ 21
Starstone | Clear Spring | Affiliated Entity
Transactions under StarStone ceding quota share, included in net earnings (loss) from discontinued operations:
Ceded premium earned		60	(3,548)	61	(13,304)
Ceded incurred losses and LAE		(525)	1,063	(1,814)	8,051
Acquisition costs		$ 17	$ (243)	$ 44	$ (305)

Related Party Transactions - Am

Related Party Transactions - AmTrust (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2019	Nov. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Purchase amount of equity interest					$ 33,000	$ 38,403
Net investment income			$ 72,130	$ 81,502	241,287	231,424
Net realized and unrealized gains			500,005	145,060	838,552	858,489
NET EARNINGS			645,850	126,559	892,718	730,355
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%
Fee income (less than)							$ 3,300
AmTrust Financial Services, Inc. | Affiliated Entity
Related Party Transaction [Line Items]
Investment in related party	$ 240,115		245,361		245,361
Net investment income			0	1,900	4,367	5,550
Net realized and unrealized gains			45	0	3,854	0
NET EARNINGS			$ 45	$ 1,900	$ 8,221	$ 5,550

Related Party Transactions - Ci

Related Party Transactions - Citco (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Jun. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Indirect investment acquired		$ 812,586	$ 731,588
Other investments		$ 3,704,870		$ 2,518,031
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		$ 51,946		$ 51,742

Related Party Transactions - En

Related Party Transactions - Enhanzed Re (Details) - USD ($) $ in Thousands	Oct. 01, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Equity method investments		$ 516,795		$ 516,795		$ 326,277
Ownership percentage		47.40%		47.40%		47.40%
Balances under ceding quota share:
Insurance balances payables		$ 581,615		$ 581,615		$ 420,546
Reinsurance balances recoverable		1,881,656		1,881,656		2,181,134
Funds held		657,490		657,490		475,732
Other assets		677,797		677,797		699,081
Premiums Earned, Net [Abstract]
Acquisition costs		37,708	$ 33,310	132,818	$ 162,192
Net investment income		72,130	81,502	241,287	231,424
Net realized and unrealized gains		500,005	145,060	838,552	858,489
NET EARNINGS		645,850	126,559	892,718	730,355
Enstar | Enhanzed Re
Related Party Transaction [Line Items]
Equity method investments		154,100		154,100
Ownership percentage							47.40%
Uncalled amount of investment		68,700		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		$ 271,678		$ 271,678		$ 182,856
Ownership percentage		47.40%		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		$ 1,759		$ 1,759		$ 1,443
Reinsurance balances recoverable		53,762		53,762		59,601
Funds held		47,808		47,808		50,089
Other assets		498		498		$ 1,033
Premiums Earned, Net [Abstract]
Ceded incurred losses and LAE		(1)	0	(14)	0
Acquisition costs		(46)	0	(23)	0
Net investment income		(819)	0	(819)	0
Net realized and unrealized gains		(679)	0	(679)	0
Other income		3,113	0	0	0
Fees and commission income		161	150	393	402
NET EARNINGS		1,729	150	(1,142)	402
Change in realized gain (losses) on available-for-sale investments		(2,239)	0	(2,239)	0
Enhanzed Re | Zurich
Related Party Transaction [Line Items]
Percentage ceded						10.00%
AXA Group | Scenario, Forecast
Related Party Transaction [Line Items]
Percentage ceded	10.00%
AmTrust Financial Services, Inc. | Affiliated Entity
Premiums Earned, Net [Abstract]
Net investment income		0	1,900	4,367	5,550
Net realized and unrealized gains		45	0	3,854	0
NET EARNINGS		$ 45	$ 1,900	$ 8,221	$ 5,550

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Guarantor Obligations [Line Items]
Funds held by reinsured companies	$ 657,490	$ 475,732
Lease optional renewal period	5 years
Lease optional termination period	1 year
Limited Parental Guarantee
Guarantor Obligations [Line Items]
Parental guarantees	$ 1,400,000	$ 1,000,000
US
Guarantor Obligations [Line Items]
Concentration of credit risk, counterparty credit exposure	1,200,000
Reinsurance Recoverables | Reinsurer Concentration Risk
Guarantor Obligations [Line Items]
Funds held by reinsured companies	948,300
Other investments
Guarantor Obligations [Line Items]
Commitments, unfunded	792,200
Equity Method Investments
Guarantor Obligations [Line Items]
Commitments, unfunded	68,700
Fixed Maturities
Guarantor Obligations [Line Items]
Commitments, unfunded	$ 15,000
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_2

Commitments and Contingencies - Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 3,036	$ 4,010	$ 9,560	$ 10,696
Short-term lease cost	63	0	182	0
Total lease cost	3,099	4,010	9,742	10,696
Sublease income	(139)	(183)	(415)	(451)
Total net lease cost	2,960	3,827	9,327	10,245
Operating cash paid for amounts included in the measurement of lease liabilities	2,856	2,945	10,184	9,138
Non-cash activity: right-of-use assets relating to leases	$ (179)	$ 1,353	$ 84	$ 53,581
Weighted-average remaining lease term	6 years 1 month 6 days	6 years 4 months 24 days	6 years 1 month 6 days	6 years 4 months 24 days
Weighted-average discount rate	6.40%	6.20%	6.40%	6.20%

Commitments and Contingencies_3

Commitments and Contingencies - Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 33,224	$ 46,747
Current lease liabilities	7,955	11,403
Non-current lease liabilities	28,126	$ 34,785
StarStone International
Lessee, Lease, Description [Line Items]
Impairment loss	3,500
Atrium | Disposal group, held-for-sale
Lessee, Lease, Description [Line Items]
Right-of-use assets	1,500
Lease liability	$ 1,000

Commitments and Contingencies_4

Commitments and Contingencies - Leases - Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
2020	$ 2,938
2021	9,347
2022	7,829
2023	7,032
2024	5,328
2025 and beyond	12,579
Total lease payments	45,053
Less: Imputed interest	(8,972)
Present value of lease liabilities	$ 36,081

Segment Information - Additiona

Segment Information - Additional Information (Details)	9 Months Ended
	Sep. 30, 2020Segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment Information - Summary o

Segment Information - Summary of Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Gross premiums written	$ 111,477	$ 157,135	$ 460,630	$ 483,912
Net premiums written	93,559	113,494	368,794	390,737
Net premiums earned	161,724	175,802	463,946	618,711
Net incurred losses and LAE	(109,686)	(163,258)	(339,678)	(566,111)
Acquisition costs	(37,708)	(33,310)	(132,818)	(162,192)
Operating expenses	(73,793)	(69,662)	(222,259)	(202,780)
Underwriting income (loss)	(59,463)	(90,428)	(230,809)	(312,372)
Net investment income	72,130	81,502	241,287	231,424
Net realized and unrealized gains (losses)	500,005	145,060	838,552	858,489
Fees and commission income	10,787	6,437	28,325	18,931
Other income (expense)	48,404	822	67,761	15,368
Corporate expenses	(42,035)	(27,703)	(136,827)	(93,524)
Interest income (expense)	(15,003)	(14,950)	(42,436)	(39,022)
Net foreign exchange gains (losses)	(8,156)	13,665	(1,375)	20,097
EARNINGS BEFORE INCOME TAXES	506,669	114,405	764,478	699,391
Income tax benefit (expense)	(13,915)	(13,465)	(25,295)	(25,265)
Earnings from equity method investments	149,065	17,703	152,725	44,188
NET EARNINGS FROM CONTINUING OPERATIONS	641,819	118,643	891,908	718,314
NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	4,031	7,916	810	12,041
NET EARNINGS	645,850	126,559	892,718	730,355
Net loss (earnings) attributable to noncontrolling interest	(21,912)	109	30,802	4,970
NET EARNINGS ATTRIBUTABLE TO ENSTAR	623,938	126,668	923,520	735,325
Dividends on preferred shares	(8,925)	(8,925)	(26,775)	(26,989)
NET EARNINGS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	615,013	117,743	896,745	708,336
Non-life Run-off
Segment Reporting Information [Line Items]
Net incurred losses and LAE	(34,258)	(30,583)	(63,698)	(135,517)
Atrium
Segment Reporting Information [Line Items]
Net incurred losses and LAE	$ (21,995)	$ (28,400)	$ (66,003)	$ (58,662)
Underwriting Ratios [Abstract]
Loss ratio	51.80%	66.20%	51.50%	48.90%
Acquisition expense ratio	33.60%	33.70%	33.70%	34.20%
Operating expense ratio	7.10%	8.70%	6.90%	8.40%
Combined ratio	92.50%	108.60%	92.10%	91.50%
StarStone
Segment Reporting Information [Line Items]
Net incurred losses and LAE	$ (48,390)	$ (100,628)	$ (197,259)	$ (358,864)
Underwriting Ratios [Abstract]
Loss ratio	50.30%	90.00%	71.30%	105.60%
Acquisition expense ratio	21.40%	20.90%	27.50%	23.70%
Operating expense ratio	21.40%	13.00%	24.00%	15.60%
Combined ratio	93.10%	123.90%	122.80%	144.90%
Operating Segments | Non-life Run-off
Segment Reporting Information [Line Items]
Gross premiums written	$ 3,535	$ 301	$ 1,707	$ (24,785)
Net premiums written	3,424	(3,808)	2,397	(26,395)
Net premiums earned	17,476	16,837	44,023	141,981
Net incurred losses and LAE	(34,258)	(30,583)	(63,698)	(135,517)
Acquisition costs	(2,730)	4,634	(13,226)	(40,033)
Operating expenses	(50,345)	(51,395)	(147,117)	(139,595)
Underwriting income (loss)	(69,857)	(60,507)	(180,018)	(173,164)
Net investment income	66,918	73,752	223,425	206,337
Net realized and unrealized gains (losses)	486,671	138,174	838,483	815,902
Fees and commission income	3,637	4,196	12,588	13,673
Other income (expense)	48,023	(285)	68,087	15,136
Corporate expenses	(22,494)	(11,983)	(48,014)	(47,287)
Interest income (expense)	(16,705)	(17,964)	(48,785)	(45,699)
Net foreign exchange gains (losses)	(9,663)	13,056	385	20,426
EARNINGS BEFORE INCOME TAXES	486,530	138,439	866,151	805,324
Income tax benefit (expense)	(9,271)	(13,382)	(18,276)	(23,501)
Earnings from equity method investments	149,065	17,703	152,725	44,406
NET EARNINGS FROM CONTINUING OPERATIONS	626,324	142,760	1,000,600	826,229
NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	0	0	0	0
NET EARNINGS	626,324	142,760	1,000,600	826,229
Net loss (earnings) attributable to noncontrolling interest	(2,519)	(1,439)	504	(6,351)
NET EARNINGS ATTRIBUTABLE TO ENSTAR	623,805	141,321	1,001,104	819,878
Dividends on preferred shares	0	0	0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	623,805	141,321	1,001,104	819,878
Operating Segments | Atrium
Segment Reporting Information [Line Items]
Gross premiums written	49,083	48,746	155,551	146,519
Net premiums written	46,503	43,785	136,093	127,246
Net premiums earned	42,426	42,913	128,183	119,865
Net incurred losses and LAE	(21,995)	(28,400)	(66,003)	(58,662)
Acquisition costs	(14,242)	(14,466)	(43,235)	(41,023)
Operating expenses	(3,008)	(3,742)	(8,757)	(9,968)
Underwriting income (loss)	3,181	(3,695)	10,188	10,212
Net investment income	1,778	1,736	4,382	5,500
Net realized and unrealized gains (losses)	1,533	582	3,392	5,464
Fees and commission income	7,150	2,391	15,737	5,773
Other income (expense)	72	35	105	106
Corporate expenses	(6,084)	(2,896)	(14,494)	(10,186)
Interest income (expense)	0	0	0	0
Net foreign exchange gains (losses)	2,275	(924)	1,115	(1)
EARNINGS BEFORE INCOME TAXES	9,905	(2,771)	20,425	16,868
Income tax benefit (expense)	(2,520)	(222)	(3,303)	(1,930)
Earnings from equity method investments	0	0	0	0
NET EARNINGS FROM CONTINUING OPERATIONS	7,385	(2,993)	17,122	14,938
NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	0	0	0	0
NET EARNINGS	7,385	(2,993)	17,122	14,938
Net loss (earnings) attributable to noncontrolling interest	(2,996)	1,228	(7,024)	(6,127)
NET EARNINGS ATTRIBUTABLE TO ENSTAR	4,389	(1,765)	10,098	8,811
Dividends on preferred shares	0	0	0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	4,389	(1,765)	10,098	8,811
Operating Segments | StarStone
Segment Reporting Information [Line Items]
Gross premiums written	58,566	110,586	300,135	363,352
Net premiums written	43,338	76,020	227,066	291,083
Net premiums earned	96,116	111,749	276,566	339,993
Net incurred losses and LAE	(48,390)	(100,628)	(197,259)	(358,864)
Acquisition costs	(20,608)	(23,301)	(76,026)	(80,582)
Operating expenses	(20,440)	(14,525)	(66,385)	(53,217)
Underwriting income (loss)	6,678	(26,705)	(63,104)	(152,670)
Net investment income	6,298	8,161	21,625	25,865
Net realized and unrealized gains (losses)	11,801	6,034	(3,323)	31,274
Fees and commission income	0	(150)	0	(515)
Other income (expense)	99	72	216	445
Corporate expenses	(3,137)	0	(39,153)	0
Interest income (expense)	(510)	0	(1,611)	(475)
Net foreign exchange gains (losses)	(761)	1,509	(5,509)	(326)
EARNINGS BEFORE INCOME TAXES	20,468	(11,079)	(90,859)	(96,402)
Income tax benefit (expense)	(733)	139	(2,325)	251
Earnings from equity method investments	0	0	0	(218)
NET EARNINGS FROM CONTINUING OPERATIONS	19,735	(10,940)	(93,184)	(96,369)
NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	4,031	7,916	810	12,041
NET EARNINGS	23,766	(3,024)	(92,374)	(84,328)
Net loss (earnings) attributable to noncontrolling interest	(16,397)	320	37,322	17,448
NET EARNINGS ATTRIBUTABLE TO ENSTAR	7,369	(2,704)	(55,052)	(66,880)
Dividends on preferred shares	0	0	0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	7,369	(2,704)	(55,052)	(66,880)
Other
Segment Reporting Information [Line Items]
Gross premiums written	293	(2,498)	3,237	(1,174)
Net premiums written	294	(2,503)	3,238	(1,197)
Net premiums earned	5,706	4,303	15,174	16,872
Net incurred losses and LAE	(5,043)	(3,647)	(12,718)	(13,068)
Acquisition costs	(128)	(177)	(331)	(554)
Operating expenses	0	0	0	0
Underwriting income (loss)	535	479	2,125	3,250
Net investment income	(2,864)	(2,147)	(8,145)	(6,278)
Net realized and unrealized gains (losses)	0	270	0	5,849
Fees and commission income	0	0	0	0
Other income (expense)	210	1,000	(647)	(319)
Corporate expenses	(10,320)	(12,824)	(35,166)	(36,051)
Interest income (expense)	2,212	3,014	7,960	7,152
Net foreign exchange gains (losses)	(7)	24	2,634	(2)
EARNINGS BEFORE INCOME TAXES	(10,234)	(10,184)	(31,239)	(26,399)
Income tax benefit (expense)	(1,391)	0	(1,391)	(85)
Earnings from equity method investments	0	0	0	0
NET EARNINGS FROM CONTINUING OPERATIONS	(11,625)	(10,184)	(32,630)	(26,484)
NET EARNINGS FROM DISCONTINUED OPERATIONS, NET OF INCOME TAXES	0	0	0	0
NET EARNINGS	(11,625)	(10,184)	(32,630)	(26,484)
Net loss (earnings) attributable to noncontrolling interest	0	0	0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR	(11,625)	(10,184)	(32,630)	(26,484)
Dividends on preferred shares	(8,925)	(8,925)	(26,775)	(26,989)
NET EARNINGS ATTRIBUTABLE TO ENSTAR ORDINARY SHAREHOLDERS	$ (20,550)	$ (19,109)	$ (59,405)	$ (53,473)

Segment Information - Summary_2

Segment Information - Summary of Company's Assets by Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 21,770,588	$ 19,826,099
Assets held-for-sale (Note 4)	2,156,488	1,474,770
Non-life Run-off | Disposal group, held-for-sale | Arden
Segment Reporting, Asset Reconciling Item [Line Items]
Assets held-for-sale (Note 4)	12,400
StarStone | Disposal group, held-for-sale | StarStone US
Segment Reporting, Asset Reconciling Item [Line Items]
Assets held-for-sale (Note 4)	1,500,000
Operating Segments | Non-life Run-off
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	17,961,439	15,775,407
Operating Segments | Atrium
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	638,529	580,405
Operating Segments | StarStone
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	4,021,240	3,985,138
Other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ (850,620)	$ (514,851)