Enstar Group Limited (ESGR) 10-K 27 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Feb. 23, 2017	Jun. 30, 2016
Document Information [Line Items]
Entity Registrant Name	Enstar Group LTD
Entity Central Index Key	1,363,829
Trading Symbol	ESGR
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Voluntary Filers	Yes
Entity Public Float			$ 1,590
Voting ordinary shares
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		16,419,889
Non-voting ordinary shares
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,004,443

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Trading, at fair value	$ 4,611,160	$ 4,813,625
Equities, trading, at fair value	95,047	111,495
Other investments, at fair value	937,047	980,289
Other investments, at cost	131,651	133,071
Total investments	6,042,672	6,340,781
Cash and cash equivalents	954,871	795,245
Restricted cash and cash equivalents	363,774	499,924
Funds held - directly managed	994,665	0
Premiums receivable	406,676	381,412
Deferred tax assets	11,374	29,906
Prepaid reinsurance premiums	219,115	121,427
Reinsurance balances recoverable	1,460,743	1,451,921
Funds held by reinsured companies	82,073	92,798
Deferred acquisition costs	58,114	89,123
Goodwill and intangible assets	184,855	191,304
Other assets	842,356	509,110
Assets held for sale	1,244,456	1,269,583
TOTAL ASSETS	12,865,744	11,772,534
LIABILITIES
Losses and loss adjustment expenses	5,987,867	5,720,149
Policy benefits for life and annuity contracts	112,095	126,321
Unearned premiums	548,343	542,771
Insurance and reinsurance balances payable	394,021	271,801
Deferred tax liabilities	28,356	32,990
Loans payable	673,603	599,750
Other liabilities	705,318	350,752
Liabilities held for sale	1,150,787	1,189,554
TOTAL LIABILITIES	9,600,390	8,834,088
COMMITMENTS AND CONTINGENCIES
REDEEMABLE NONCONTROLLING INTEREST	454,522	417,663
SHAREHOLDERS’ EQUITY
Treasury shares at cost (Preferred shares 2016: 388,571; Series A non-voting convertible ordinary shares 2015: 2,972,892)	(421,559)	(421,559)
Additional paid-in capital	1,380,109	1,373,044
Accumulated other comprehensive loss	(23,549)	(35,162)
Retained earnings	1,847,550	1,578,312
Total Enstar Group Limited Shareholders’ Equity	2,802,312	2,516,872
Noncontrolling interest	8,520	3,911
TOTAL SHAREHOLDERS’ EQUITY	2,810,832	2,520,783
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTEREST AND SHAREHOLDERS’ EQUITY	12,865,744	11,772,534
Voting ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	16,175	16,133
Series A non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	0	2,973
Series C non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	2,792	2,726
Series E non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	405	405
Series C non-voting preferred shares
SHAREHOLDERS’ EQUITY
Series C Preferred Shares (issued and outstanding 2016: 388,571; 2015: nil)	389	0
Short-term investments
ASSETS
Trading, at fair value	222,918	85,104
Available-for-sale, at fair value	268	8,622
Fixed maturities
ASSETS
Trading, at fair value	4,388,242	4,728,521
Available-for-sale, at fair value	$ 267,499	$ 293,679

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Short-term investments, available-for-sale, at fair value, amortized cost	$ 269,864	$ 308,790
Ordinary shares, par value (in dollars per share)	$ 1	$ 1
Preferred shares, par value (dollars per share)	$ 1	$ 1
Share capital, authorized (shares)	156,000,000	156,000,000
Voting ordinary shares
Ordinary shares, par value (in dollars per share)	$ 1	$ 1
Ordinary shares, issued (shares)	16,175,250	16,133,334
Ordinary shares, outstanding (shares)	16,175,250	16,133,334
Series A non-voting convertible ordinary shares
Ordinary shares, issued (shares)	0	2,972,892
Treasury shares (shares)	0	2,972,892
Series C non-voting convertible ordinary shares
Ordinary shares, issued (shares)	2,792,157	2,725,637
Ordinary shares, outstanding (shares)	2,792,157	2,725,637
Series E non-voting convertible ordinary shares
Ordinary shares, issued (shares)	404,771	404,771
Ordinary shares, outstanding (shares)	404,771	404,771
Series C non-voting preferred shares
Preferred shares, issued (shares)	388,571	0
Preferred shares, outstanding (shares)	388,571	0
Treasury shares (shares)	388,571	0
Short-term investments
Short-term investments, available-for-sale, at fair value, amortized cost	$ 287	$ 8,630
Fixed maturities
Short-term investments, available-for-sale, at fair value, amortized cost	$ 269,577	$ 300,160

Consolidated Statements of Earn

Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INCOME
Net premiums earned	$ 216,188	$ 205,730	$ 208,709	$ 192,887	$ 178,009	$ 209,971	$ 189,344	$ 176,420	$ 823,514	$ 753,744	$ 542,991
Fees and commission income	13,266	9,187	10,487	6,424	7,450	9,708	10,125	12,064	39,364	39,347	34,919
Net investment income	42,229	48,022	44,932	50,280	44,265	31,640	25,265	21,394	185,463	122,564	66,024
Net realized and unrealized gains (losses)	(61,570)	66,608	34,503	38,277	(56,705)	(15,835)	(8,296)	39,313	77,818	(41,523)	51,991
Other income	(1,277)	414	3,289	2,410	12,648	2,370	11,833	3,477	4,836	30,328	14,149
Total income	208,836	329,961	301,920	290,278	185,667	237,854	228,271	252,668	1,130,995	904,460	710,074
EXPENSES
Net incurred losses and loss adjustment expenses	1,321	(6,902)	96,462	83,218	(64,062)	32,359	65,900	70,136	174,099	104,333	9,146
Life and annuity policy benefits	(2,265)	1,682	(1,613)	158	(1,808)	401	407	454	(2,038)	(546)	84
Acquisition costs	47,619	50,074	43,847	45,029	53,666	44,445	33,781	31,824	186,569	163,716	117,542
General and administrative expenses	123,497	103,097	104,206	92,934	106,754	96,818	90,837	94,750	423,734	389,159	337,120
Interest expense	4,796	5,027	5,421	5,398	5,368	5,156	4,876	4,003	20,642	19,403	12,922
Net foreign exchange losses	(1,527)	2,276	(1,856)	1,772	7,004	(841)	2,297	(5,087)	665	3,373	5,962
Total expenses	173,441	155,254	246,467	228,509	106,922	178,338	198,098	196,080	803,671	679,438	482,776
EARNINGS BEFORE INCOME TAXES	35,395	174,707	55,453	61,769	78,745	59,516	30,173	56,588	327,324	225,022	227,298
INCOME TAXES	(11,228)	(8,227)	(8,050)	(7,369)	15,794	(12,684)	(8,087)	(7,673)	(34,874)	(12,650)	(5,601)
NET EARNINGS FROM CONTINUING OPERATIONS	24,167	166,480	47,403	54,400	94,539	46,832	22,086	48,915	292,450	212,372	221,697
NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE	5,483	3,897	2,378	205	(1,898)	(831)	(3,879)	4,577	11,963	(2,031)	5,539
NET EARNINGS	29,650	170,377	49,781	54,605	92,641	46,001	18,207	53,492	304,413	210,341	227,236
Less: Net loss (earnings) attributable to noncontrolling interest	(7,005)	(14,329)	(9,187)	(9,085)	19,216	3,041	(3,662)	(8,645)	(39,606)	9,950	(13,487)
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED	$ 22,645	$ 156,048	$ 40,594	$ 45,520	$ 111,857	$ 49,042	$ 14,545	$ 44,847	$ 264,807	$ 220,291	$ 213,749
Basic:
Net earnings from continuing operations (dollars per share)	$ 0.91	$ 7.86	$ 1.99	$ 2.34	$ 5.91	$ 2.57	$ 0.99	$ 2.04	$ 13.10	$ 11.55	$ 11.31
Net earnings (loss) from discontinuing operations (dollars per share)	0.26	0.23	0.11	0.02	(0.11)	(0.02)	(0.23)	0.29	0.62	(0.11)	0.30
Net earnings per ordinary share (dollars per share)	1.17	8.09	2.10	2.36	5.80	2.55	0.76	2.33	13.72	11.44	11.61
Diluted:
Net earnings from continuing operations (dollars per share)	0.90	7.79	1.98	2.33	5.86	2.55	0.98	2.03	13	11.46	11.15
Net earnings (loss) from discontinuing operations (dollars per share)	0.26	0.23	0.11	0.02	(0.11)	(0.02)	(0.23)	0.29	0.62	(0.11)	0.29
Net earnings per ordinary share (dollars per share)	$ 1.16	$ 8.02	$ 2.09	$ 2.35	$ 5.75	$ 2.53	$ 0.75	$ 2.32	$ 13.62	$ 11.35	$ 11.44
Weighted average ordinary shares outstanding:
Weighted average ordinary shares outstanding - basic (shares)									19,299,426	19,252,072	18,409,069
Weighted average ordinary shares outstanding - diluted (shares)									19,447,241	19,407,756	18,678,130

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
NET EARNINGS	$ 304,413	$ 210,341	$ 227,236
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on fixed income investments arising during the year	4,776	(3,219)	(6,297)
Reclassification adjustment for net realized gains included in net earnings	(384)	(266)	(58)
Unrealized gains (losses) arising during the year, net of reclassification adjustment	4,392	(3,485)	(6,355)
Decrease (increase) in defined benefit pension liability	3,079	3	(5,477)
Currency translation adjustment	4,793	(24,694)	(19,421)
Total other comprehensive gain (loss)	12,264	(28,176)	(31,253)
Comprehensive income	316,677	182,165	195,983
Less comprehensive (income) loss attributable to noncontrolling interest	(40,257)	15,650	(8,898)
COMPREHENSIVE INCOME ATTRIBUTABLE TO ENSTAR GROUP LIMITED	$ 276,420	$ 197,815	$ 187,085

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Treasury Shares	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Currency translation adjustment	Defined benefit pension liability	Unrealized gains (losses) on investments	Retained Earnings	Noncontrolling Interest (excludes redeemable noncontrolling interests)	Foreign currency translation adjustments	Net movement in unrealized holding losses on investments	Voting ordinary sharesOrdinary Shares	Series A non-voting convertible ordinary sharesOrdinary Shares	Series C non-voting convertible ordinary sharesOrdinary Shares	Series E non-voting convertible ordinary sharesOrdinary Shares	Share Capital Series B Convertible Participating Non-Voting Perpetual Preferred StockPreferred Stock	Series C non-voting preferred sharesPreferred Stock
Balance, beginning of year at Dec. 31, 2013			$ 962,145	$ 13,978	$ 14,264	$ (2,249)	$ 1,963	$ 1,181,457	$ 222,000			$ 13,803	$ 2,973	$ 2,726	$ 0	$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares												1,958				714
Issue of shares and warrants			354,622
Conversion of convertible securities			0									0	0		714	(714)	0
Warrants exercised														0
Amortization of share-based compensation			4,948
Equity attributable to purchase of noncontrolling shareholders’ interest in subsidiaries			0
Purchase of noncontrolling shareholders' interest in subsidiaries					0		0		0
Change in defined benefit pension liability	$ (5,477)					(5,477)
Net earnings (loss)								213,749	9,429
Change in redemption of redeemable noncontrolling interests								0
Return of capital									(11,864)
Dividends paid									(18,108)
Contribution of capital									18,081
Reallocation from (to) redeemable noncontrolling interest									1,028
Other comprehensive income (loss)	(31,253)				(17,043)		(4,144)			$ (2,181)	$ (415)
Balance, end of year at Dec. 31, 2014		$ (421,559)	1,321,715	(12,686)	(2,779)	(7,726)	(2,181)	1,395,206	217,970			15,761	2,973	2,726	714	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares												63				0
Issue of shares and warrants			1,765
Conversion of convertible securities			0									309	0		(309)	0	0
Warrants exercised														0
Amortization of share-based compensation			7,867
Equity attributable to purchase of noncontrolling shareholders’ interest in subsidiaries			41,697
Purchase of noncontrolling shareholders' interest in subsidiaries					2,937		312		(195,347)
Change in defined benefit pension liability	3					3
Net earnings (loss)								220,291	(1,153)
Change in redemption of redeemable noncontrolling interests								(37,185)
Return of capital									0
Dividends paid									(733)
Contribution of capital									680
Reallocation from (to) redeemable noncontrolling interest									(15,801)
Other comprehensive income (loss)	(28,176)				(23,948)		(1,780)			(1,558)	(147)
Balance, end of year at Dec. 31, 2015	2,520,783	(421,559)	1,373,044	(35,162)	(23,790)	(7,723)	(3,649)	1,578,312	3,911			16,133	2,973	2,726	405	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares												42				0
Issue of shares and warrants			529
Conversion of convertible securities			2,584									0	(2,973)		0	0	389
Warrants exercised														66
Amortization of share-based compensation			3,952
Equity attributable to purchase of noncontrolling shareholders’ interest in subsidiaries			0
Purchase of noncontrolling shareholders' interest in subsidiaries					0		0		0
Change in defined benefit pension liability	3,079					3,079
Net earnings (loss)								264,807	(1,034)
Change in redemption of redeemable noncontrolling interests								4,431
Return of capital									0
Dividends paid									0
Contribution of capital									5,643
Reallocation from (to) redeemable noncontrolling interest									0
Other comprehensive income (loss)	12,264				4,797		3,737			$ 0	$ 0
Balance, end of year at Dec. 31, 2016	$ 2,810,832	$ (421,559)	$ 1,380,109	$ (23,549)	$ (18,993)	$ (4,644)	$ 88	$ 1,847,550	$ 8,520			$ 16,175	$ 0	$ 2,792	$ 405	$ 0	$ 389

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES:
Net earnings	$ 304,413	$ 210,341	$ 227,236
Net (earnings) loss from discontinued operations	(11,963)	2,031	(5,539)
Adjustments to reconcile net earnings to cash flows provided by (used in) operating activities:
Realized losses (gains) on sale of investments	7,036	(15,859)	(22,169)
Unrealized losses (gains) on investments	(84,854)	57,380	(29,810)
Other non-cash items	8,566	3,984	(1,268)
Depreciation and other amortization	34,938	40,922	43,870
Net change in trading securities held on behalf of policyholders	(1,284)	(7,241)	4,256
Sales and maturities of trading securities	3,406,788	3,651,680	2,836,921
Purchases of trading securities	(3,100,515)	(4,052,430)	(1,986,441)
Changes in:
Reinsurance balances recoverable	(21,866)	391,182	428,718
Funds held by reinsured companies	(967,379)	32,435	114,348
Losses and loss adjustment expenses	259,339	(276,711)	(967,263)
Policy benefits for life and annuity contracts	(11,037)	9,110	(839)
Insurance and reinsurance balances payable	120,515	(20,635)	(190,464)
Unearned premiums	5,682	(19,355)	8,000
Other operating assets and liabilities	(151,068)	(271,986)	84,449
Net cash flows provided by (used in) operating activities	(202,689)	(265,152)	544,005
INVESTING ACTIVITIES:
Acquisitions, net of cash acquired	(18,454)	130,667	60,319
Sales and maturities of available-for-sale securities	81,596	142,824	109,994
Purchase of available-for-sale securities	(52,568)	(102,214)	(116,738)
Purchase of other investments	(91,093)	(315,583)	(346,313)
Redemption of other investments	245,069	165,711	104,684
Other investing activities	(7,841)	(1,520)	632
Net cash flows provided by (used in) investing activities	156,709	19,885	(187,422)
FINANCING ACTIVITIES:
Distribution of capital to noncontrolling interest	0	0	(11,864)
Contribution by redeemable noncontrolling interest	5,643	680	17,768
Contribution by redeemable noncontrolling interest	0	15,728	273,035
Dividends paid to noncontrolling interest	0	(16,861)	(18,108)
Purchase of noncontrolling interest	0	(150,400)	0
Receipt of loans	571,048	657,700	70,000
Repayment of loans	(493,250)	(377,500)	(199,245)
Net cash flows provided by financing activities	83,441	129,347	131,586
EFFECT OF EXCHANGE RATE CHANGES ON FOREIGN CURRENCY CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(13,985)	(18,533)	(17,546)
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	23,476	(134,453)	470,623
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF YEAR	1,295,169	1,429,622	958,999
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, END OF YEAR	1,318,645	1,295,169	1,429,622
Supplemental Cash Flow Information:
Income taxes paid, net of refunds	22,216	33,305	41,830
Interest paid	19,451	19,395	16,130
Reconciliation to Consolidated Balance Sheets:
Cash, cash equivalents and restricted cash	$ 1,295,169	$ 1,429,622	$ 958,999

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	DESCRIPTION OF BUSINESS Enstar Group Limited ("Enstar") is a multi-faceted insurance group that offers innovative capital release solutions and specialty underwriting capabilities through its network of group companies in Bermuda, the United States, the United Kingdom, Continental Europe, Australia, and other international locations. Our ordinary shares are listed on the NASDAQ Global Select Market under the ticker symbol "ESGR". Unless the context indicates otherwise, the terms "Enstar," "we," "us" or "our" mean Enstar Group Limited and its consolidated subsidiaries and the term "Parent Company" means Enstar Group Limited and not any of its consolidated subsidiaries. Our business is organized into four segments: (i) Non-life Run-off - This segment is comprised of the operations of our subsidiaries that are running off their property and casualty and other non-life business. It also includes our management business, which manages the run-off portfolios of third parties through our service companies. (ii) Atrium - Atrium Underwriters Ltd. is a managing general agent at Lloyd’s of London ("Lloyd's"), which manages Syndicate 609. Through a corporate capital vehicle, Atrium 5 Ltd., we provide 25% of the syndicate’s underwriting capacity and capital (with the balance provided by traditional Lloyd’s Names). Atrium underwrites specialist marine, energy, aerospace, non-marine and liability classes. (iii) StarStone - StarStone is a global specialty insurer that underwrites a diverse range of property, casualty and specialty insurance through its operations in Bermuda, the United States, the United Kingdom, and Continental Europe. Certain run-off business of StarStone is recorded in our Non-life Run-off segment. (iv) Life and Annuities - This segment comprises our subsidiaries managing our closed-blocks of life and annuity business and our life settlements business.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES Basis of Preparation The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP"). The consolidated financial statements include our assets, liabilities and results of operations as of December 31, 2016 and 2015 and for the years ended December 31, 2016 , 2015 and 2014 . Results of operations for acquired subsidiaries are included from the date of acquisition. All significant intercompany transactions and balances have been eliminated. Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications had no impact on net earnings. Use of Estimates The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Our actual results could differ materially from our estimates. 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"); • liability for policy benefits for life and annuity contracts; • reinsurance balances recoverable; • gross and net premiums written and net premiums earned; • impairment charges, including other-than-temporary impairments on investment securities classified as available-for-sale, and impairments on goodwill, intangible assets and deferred charges; • fair value measurements of investments; • fair value estimates associated with accounting for acquisitions; and • redeemable noncontrolling interests. Significant Accounting Policies (a) Premiums Non-Life Non-life premiums written are earned on a pro-rata basis over the period the coverage is provided. Reinsurance premiums are recorded at the inception of the policy, are based upon contractual terms and, for certain business, are estimated based on underlying contracts or from information provided by insureds and/or brokers. Changes in reinsurance premium estimates are expected and may result in adjustments in future periods. Any subsequent differences arising on such estimates are recorded as premiums written in the period in which they are determined. Certain non-life contracts are retrospectively rated and provide for a final adjustment to the premium based on the final settlement of all losses. Premiums on such contracts are adjusted based upon contractual terms, and management judgme nt is involved with respect to the estimate of the amount of losses that we expect to incur. Additional premiums are recognized at the time loss thresholds specified in the contract are exceeded and are earned over the coverage period, or are earned immediately if the period of risk coverage has passed. Life and Annuities Prior to going into run-off, our life and annuities subsidiaries wrote life insurance, including credit life and disability insurance, term life insurance, assumed life reinsurance and annuities. We will continue to recognize premiums on term life insurance, assumed life reinsurance and credit life and disability insurance. These premiums are generally recognized as revenue when due from policyholders. The policies include contracts with fixed and guaranteed premiums and benefits. Benefits and expenses are matched with such revenue to result in the recognition of profit over the life of the contracts. Premiums receivable Premiums receivable represent amounts currently due and amounts not yet due on insurance and reinsurance policies. Premiums for insurance policies are generally due at inception. Premiums for reinsurance policies generally become due over the period of coverage based on the policy terms. We monitor the credit risk associated with premiums receivable, taking into consideration the impact of our contractual right to offset loss obligations or unearned premiums against premiums receivable. Amounts deemed uncollectible are charged to net earnings in the period they are determined. Changes in the estimates of premiums written will result in an adjustment to premiums receivable in the period they are determined. Unearned premiums and prepaid reinsurance premiums Unearned premiums represent the portion of premiums written that relate to the unexpired terms of policies in force. Premiums ceded are similarly pro-rated over the period the coverage is provided with the unearned portion being deferred as prepaid reinsurance premiums. (b) Acquisition Costs Acquisition costs, consisting principally of commissions and brokerage expenses and certain premium taxes and fees incurred at the time a contract or policy is issued and that vary with and are directly related to the successful efforts of acquiring new insurance contracts or renewing existing insurance contracts, are deferred and amortized over the period in which the related premiums are earned. Deferred acquisition costs are limited to their estimated realizable value by line of business based on the related unearned premiums, anticipated claims and claim expenses and anticipated investment income. (c) Losses and LAE Non-life Run-off The liability for losses and LAE in the Non-life Run-off segment includes an amount determined from reported claims and an amount, based on historical loss experience and industry statistics, for losses incurred but not reported ("IBNR") determined using a variety of actuarial methods. These estimates are continually reviewed and are necessarily subject to the impact of future changes in factors such as claim severity and frequency, changes in economic conditions including the impact of inflation, legal and judicial developments, and medical cost trends. While we believe that the amount is adequate, the ultimate liability may be in excess of, or less than, the amounts provided. Adjustments will be reflected as part of net increase or reduction in losses and LAE liabilities in the periods in which they become known. Premium and commission adjustments may be triggered by incurred losses, and any amounts are recorded in the same period that the related incurred loss is recognized. Commutations of acquired companies’ exposures have the effect of accelerating the payout of claims compared to the probability-weighted ranges of actuarially projected cash flows that we apply when estimating the fair values of assets and liabilities at the time of acquisition. Any material acceleration of payout together with the impact of any material loss reserve savings in any period will also accelerate the amortization of fair value adjustments in that period. Gains or losses on settlement of losses and LAE liabilities by way of commutation or policy buy-back are recognized upon execution of a commutation or policy buyback with the insured or reinsured. Our insurance and reinsurance subsidiaries also establish provisions for LAE relating to run-off costs for the estimated duration of the run-off, which are included in losses and LAE. These provisions are assessed at each reporting date, and provisions relating to future periods are adjusted to reflect any changes in estimates of the periodic run-off costs or the duration of the run-off, including the impact of any acceleration of the run-off period that may be caused by commutations. Provisions relating to the current period together with any adjustment to future run-off provisions are included in net incurred losses and LAE in the consolidated statements of earnings. Atrium and StarStone The reserves for losses and LAE in the Atrium and StarStone segments include reserves for unpaid reported losses and for IBNR loss reserves. The reserves for unpaid reported losses and loss expenses are established by management based on reports from brokers, ceding companies and insureds and represent the estimated ultimate cost of events or conditions that have been reported to or specifically identified by us. The reserve for IBNR losses is established by us based on actuarially determined estimates of ultimate losses and loss expenses. Inherent in the estimate of ultimate losses and loss expenses are expected trends in claim severity and frequency and other factors which may vary significantly as claims are settled. Accordingly, ultimate losses and loss expenses may differ from the amounts recorded in the consolidated financial statements. These estimates are reviewed regularly and, as experience develops and new information becomes known, the reserves are adjusted as necessary. Such adjustments, if any, will be recorded in earnings in the period in which they become known. Prior period development arises from changes to loss estimates recognized in the current year that relate to loss reserves established in prev ious calendar years. (d) Policy Benefits for Life and Annuity Contracts Policy benefits for life and annuity contracts (“policy benefits”) are calculated using the net level premium method and are derived using locked-in assumptions. Policy benefits are established and maintained at a level that we estimate will, when taken together with future premium payments and investment income expected to be earn ed on associated premiums, be sufficient to support all future cash flow benefit obligations and third-party servicing obligations as they become payable. We review policy benefits regularly and perform loss recognition testing based upon cash flow projections. Since the development of the policy benefits is based upon projections of future cash flows, we are required to make assumptions for mortality, longevity and morbidity rates, lapse rates, expenses and investment income. The assumptions used to determine policy benefits are determined at the inception of the contracts, reviewed and adjusted at the point of acquisition, as required, and are locked-in throughout the life of the contract unless a premium deficiency develops. These locked-in assumptions are based on a best estimate view of experience at the time they are established and may include a provision for adverse deviation. Assumptions are established based upon a combination of historical and industry experience, when available, and management judgment. Actual results could differ from these estimates. Policy benefit liabilities are reviewed periodically to determine whether a premium deficiency exists. Management reviews emerging experience and updates best estimate assumptions where appropriate. If existing policy benefit reserves, reduced by unamortized acquisition costs, together with the present value of future gross premiums using current best estimate assumptions, are insufficient in covering the present value of future benefits, settlement, and maintenance costs using current best estimate assumptions, a premium deficiency is deemed to exist. To remediate, unamortized acquisition costs are reduced until the premium deficiency has been eliminated. If unamortized acquisition costs have been entirely written off and a premium deficiency still exists, locked-in assumptions are revised and a charge for policy benefits is recognized. Because of the many assumptions and estimates used in establishing policy benefits and the long-term nature of the contracts, the reserving process, while based on actua rial techniques, is inherently uncertain. (e) Reinsurance Recoverable Amounts billed to, and due from, reinsurers resulting from paid movements in the underlying business are calculated in accordance with the terms of the individual reinsurance contracts. Similarly, reinsurance balances recoverable related to our case reserves are calculated by applying the terms of any applicable reinsurance coverage to movements in the underlying case reserves. Our estimate of reinsurance balances recoverable related to IBNR reserves is recognized on a basis consistent with the underlying IBNR reserves. Our reinsurance balances recoverable are presented net of a provision for uncollectible amounts, reflecting the amount deemed not collectible due to credit quality, collection problems due to the location of the reinsurer, contractual disputes with reinsurers over individual contentious claims, contract language or coverage issues. (f) Investments, Cash and Cash Equivalents Short-term investments and fixed maturity investments Short-term investments comprise investments with a maturity greater than three months up to one year from the date of purchase. Fixed maturities comprise investments with a maturity of greater than one year from the date of purchase. Short-term and fixed maturity investments classified as trading are carried at fair value, with realized and unrealized holding gains and losses included in net earnings and reported as net realized and unrealized gains and losses. Short-term and fixed maturity investments classified as available-for-sale are carried at fair value, with unrealized gains and losses excluded from net earnings and reported as a separate component of accumulated other comprehensive income. Realized gains and losses on sales of investments classified as available-for-sale are recognized in the consolidated statements of earnings. The costs of short-term and fixed maturity investments are adjusted for amortization of premiums and accretion of discounts, recognized using the effective yield method and included in net investment income. For mortgage-backed and asset-backed investments, and any other holdings for which there is a prepayment risk, prepayment assumptions are evaluated and reviewed on a regular basis. Investment purchases and sales are recorded on a trade-date basis. Realized gains and losses on the sale of investments are based upon specific identification of the cost of investments. Other-Than-Temporary Impairments Fixed maturity investments classified as available-for-sale are reviewed quarterly to determine if they have sustained an impairment of value that is, based on our judgment, considered to be other than temporary. The process includes reviewing each fixed maturity investment that is below cost and: (1) determining if we have the intent to sell the fixed maturity investment; (2) determining if it is more likely than not that we will be required to sell the fixed maturity investment before its anticipated recovery; and (3) assessing whether a credit loss exists, that is, whether we expect that the present value of the cash flows expected to be collected from the fixed maturity investment is less than the amortized cost basis of the investment. In assessing whether it is more likely than not that we will be required to sell a fixed maturity investment before its anticipated recovery, we consider various factors including our future cash flow requirements, legal and regulatory requirements, the level of our cash, cash equivalents, short-term investments and fixed maturity investments available-for-sale in an unrealized gain position, and other relevant factors. In evaluating credit losses, we consider a variety of factors in the assessment of a fixed maturity investment including: (1) the time period during which there has been a significant decline below cost; (2) the extent of the decline below cost and par; (3) the potential for the investment to recover in value; (4) an analysis of the financial condition of the issuer; (5) the rating of the issuer; and (6) failure of the issuer of the investment to make scheduled interest or principal payments. If we conclude an investment is other-than-temporarily impaired ("OTTI"), then the difference between the fair value and the amortized cost of the investment is presented as an OTTI charge in the consolidated statements of earnings, with an offset for any non-credit related loss component of the OTTI charge to be recognized in other comprehensive income. Accordingly, only the credit loss component of the OTTI amount would have an impact on our earnings. Equities Equities are classified as trading and are carried at fair value with realized and unrealized holding gains and losses included in net earnings and reported as net realized and unrealized gains and losses. Other investments, at fair value Other investments include investments in limited partnerships and limited liability companies (collectively "private equities") and fixed income funds, hedge funds, equity funds, real estate debt funds and collateralized loan obligation ("CLO") equity funds that carry their investments at fair value, as well as direct investments in CLO equities. These other investments are stated at fair value, which ordinarily will be the most recently reported net asset value as advised by the fund manager or administrator. Many of our fund investments publish net asset values on a daily basis and provide daily liquidity; others report on a monthly basis. Private equities typically report quarterly. The change in fair value is included in net realized and unrealized gains and losses on investments and recognized in net earnings. Other investments, at cost Investments in life settlements are recorded as other investments, at cost, and are accounted for under the investment method whereby we recognize our initial investment in the life settlement contracts at the transaction price plus all initial direct external costs. Continuing costs to keep the policy in force, primarily life insurance premiums, increase the carrying amount of the investment. We recognize income on individual investments in life settlements when the insured dies, at an amount equal to the excess of the investment proceeds over the carrying amount of the investment at that time. The investments are subject to quarterly impairment review on a contract-by-contract basis. An investment in life settlements is considered impaired if the undiscounted cash flows resulting from the expected proceeds from the investment in life settlements are not sufficient to recover the current carrying amount for the investment in life settlements plus anticipated undiscounted future premiums and other capitalizable future costs, if any. Impaired contracts are written down to their estimated fair value, which is determined on a discounted cash flow basis using current market longevity assumptions and market yields, with any impairment charges included within net realized and unrealized gains (losses). Cash and cash equivalents Cash equivalents includes all highly liquid debt instruments purchased with an original maturity of three months or less. (g) Funds Held Under funds held arrangements, the reinsured company has retained funds that would otherwise have been remitted to our reinsurance subsidiaries. The funds balance is credited with investment income and losses payable are deducted. Funds held are shown under two categories on the consolidated balance sheets, where funds held upon which we receive the underlying portfolio economics are shown as "Funds held - directly managed", and funds held where we receive a fixed crediting rate are shown as "Funds held by reinsured companies". Funds held by reinsured companies are carried at cost. Funds held - directly managed, carried at fair value, represents the aggregate of funds held at cost and the value of an embedded derivative. The embedded derivative relates to our contractual right to receive the return on the underlying investment portfolio economics. The investment returns on both categories of funds held are recognized in net investment income and net realized and unrealized gains (losses). The revaluation of the embedded derivative is included in net unrealized gains (losses). (h) Fees and Commission Income Fees and commission income primarily includes profit commissions earned from managed Lloyd's syndicates, recorded on an accrual basis. (i) Foreign Exchange Our reporting currency is the U.S. dollar. Assets and liabilities of entities whose functional currency is not the U.S. dollar are translated at period end exchange rates. Revenues and expenses of such foreign entities are translated at average exchange rates during the year. The effect of the currency translation adjustments for these foreign entities is included in accumulated other comprehensive income (loss). Other foreign currency assets and liabilities that are considered monetary items are translated at exchange rates in effect at the balance sheet date. Foreign currency revenues and expenses are translated at transaction date exchange rates. These exchange gains and losses are recognized in net earnings. (j) Share-based Compensation We have primarily used three types of share-based compensation: restricted shares and restricted share units, cash-settled stock appreciation rights ("SARs") and shares issued under our employee share purchase plans. With the exception of SARs and the incentive plan awards issued to certain employees of Atrium, our share-based compensation awards qualify for equity classification. The fair value of the compensation cost is measured at the grant date and is expensed over the service period of the award. The SARs and the Atrium incentive plan awards are classified as liability awards. Liability classified awards are recorded at fair value within other liabilities in the consolidated balance sheet with changes in fair value relating to the vested portion of the award recorded within general and administrative expenses in the consolidated statements of earnings. (k) Derivative Instruments We recognize all derivatives as either assets or liabilities in the consolidated balance sheets and carry them at the fair value of the instrument. We utilize derivative instruments in our foreign currency risk management strategy. Changes in fair value and realized gains or losses on derivative instruments are recognized in net earnings if we have not designated a hedge or the criteria for a designated hedge has not been met or is not effective, or in accumulated other comprehensive income (loss) if a designated hedge has been effective. Certain of our funds held contain embedded derivatives as described above. (l) Income Taxes Certain of our subsidiaries and branches operate in jurisdictions where they are subject to taxation. Current and deferred income taxes are charged or credited to net income, or, in certain cases, to accumulated other comprehensive income, based upon enacted tax laws and rates applicable in the relevant jurisdiction in the period in which the tax becomes accruable or realizable. Deferred income taxes are provided for all temporary differences between the bases of assets and liabilities used in the financial statements and those used in the various jurisdictional tax returns. When our assessment indicates that it is more likely than not that all or some portion of deferred income tax assets will not be realized, a valuation allowance is recorded against the deferred tax assets. We recognize a tax benefit relating to uncertain tax positions only where the position is more likely than not to be sustained assuming examination by tax authorities. A liability is recognized for any tax benefit (along with any interest and penalty, if applicable) claimed in a tax return in excess of the amount allowed to be recognized in the financial statements under U.S. GAAP. Any changes in amounts recognized are recorded in the period in which they are determined. (m) Earnings Per Share Basic earnings per share is based on the weighted average number of ordinary shares outstanding and excludes potentially dilutive securities such as restricted shares, restricted share units, warrants, options and convertible securities. Diluted earnings per share is based on the weighted average number of ordinary and ordinary share equivalents outstanding calculated using the treasury stock method for all potentially dilutive securities. When the effect of dilutive securities would be anti-dilutive, these securities are excluded from the calculation of diluted earnings per share. (n) Acquisitions, Goodwill and Intangible Assets The purchase method is used to account for acquisitions. This method requires that we record the acquired assets and liabilities at their estimated fair value. The fair values of each of the acquired reinsurance assets and liabilities are derived from probability-weighted ranges of the associated projected cash flows, based on actuarially prepared information and management’s run-off strategy. Our run-off strategy, as well as that of other run-off market participants, is expected to be different from the seller's as generally sellers are not specialized in running off insurance and reinsurance liabilities whereas we and other market participants do specialize in such run-offs. The key assumptions used by us and, we believe, by other run-off market participants in the fair valuation of acquired companies are (i) the projected payout, timing and amount of claims liabilities; (ii) the related projected timing and amount of reinsurance collections; (iii) an appropriate discount rate, which is applied to determine the present value of the future cash flows; (iv) the estimated unallocated LAE to be incurred over the life of the run-off; (v) the impact of any accelerated run-off strategy; and (vi) an appropriate risk margin. The difference between the original carrying value of reinsurance liabilities and reinsurance assets acquired at the date of acquisition and their fair value is recorded as an intangible asset or other liability, which we refer to as the fair value adjustment ("FVA"). The FVA is amortized over the estimated payout period of outstanding losses and loss expenses acquired. To the extent the actual payout experience after the acquisition is materially faster or slower than anticipated at the time of the acquisition, there is an adjustment to the estimated ultimate loss reserves, or there are changes in bad debt provisions or in estimates of future run-off costs following accelerated payouts, then the amortization of the FVA is adjusted to reflect such changes. The difference between the fair value of net assets acquired and purchase price is recorded as a goodwill asset or as a gain on bargain purchase in the consolidated statements of earnings. Goodwill is established initially upon acquisition and assessed at least annually for impairment. If the goodwill asset is determined to be impaired it is written down in the period in which the determination is made. Intangible assets represent the fair value adjustments related to unpaid losses and LAE, reinsurance balances recoverable and policy benefits for life and annuity contracts along with the intangible assets arising from the acquisitions of Atrium and StarStone. Definite-lived intangible assets are amortized over their useful lives. Amortization of intangible assets is recognized in the consolidated statement of earnings. Indefinite-lived intangible assets are not subject to amortization. The carrying values of intangible assets are reviewed for indicators of impairment at least annually. Impairment is recognized if the carrying values of the intangible assets are not recoverable from their undiscounted cash flows and are measured as the difference between the carrying value and the fair value. (o) Retroactive Reinsurance and Deferred Charges Retroactive reinsurance policies provide indemnification of losses and LAE with respect to past loss events. In our Non-life Run-off segment we use the balance sheet accounting approach for assumed loss portfolio transfers, whereby at the inception of the contract there are no premiums or losses recorded in earnings. At the inception of a contract, a deferred charge asset is recorded for the excess, if any, of the estimated ultimate losses payable over the premiums received. Deferred charges, recorded in other 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 charges 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 charges and the amount of periodic amortization. Deferred charges 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. In our Non-life Run-off and StarStone segments we have ceded business to KaylaRe Ltd., an affiliated reinsurer, as described in Note 21 - "Related Party Transactions". The reinsurance ceded by StarStone to KaylaRe Ltd. during the year ended December 31, 2016 was mostly recognized as retroactive reinsurance, except for the unearned ceded premium as at December 31, 2016 which is recognized as prospective reinsurance. The reinsurance ceded by StarStone to KaylaRe Ltd. from January 1, 2017 will be recognized as prospective reinsurance. (p) Redeemable Noncontrolling Interest In connection with the acquisitions of Arden, Atrium and StarStone, certain subsidiaries issued shares to noncontrolling interests. These shares provide certain redemption rights to the holders, which may be settled in our own shares or cash, at our option. Redeemable noncontrolling interest with redemption features that are not solely within our control are classified within temporary equity in the consolidated balance sheets and carried at the redemption value, which is fair value. Change in the fair value is recognized through retained earnings as if the balance sheet date were also the redemption date. (q) Internal-use Software Direct internal and external costs to acquire or develop internal-use software have been capitalized. We only capitalize costs incurred after the preliminary project stage has been completed, and when management has authorized and committed to funding the project and it is probable that the project will be completed and the software will be used to perform the functions intended. Capitalized costs related to internal-use software are amortized on a straight-line basis over the estimated useful lives of the assets. These capitalized costs are also assessed for impairment when impairment indicators exist. (r) Held-for-sale Business and Discontinued Operations We report a business as held-for-sale when management has approved the sale or received approval to sell the business and is committed to a formal plan, the business is available for immediate sale, the business is being actively marketed, the sale is anticipated to occur during the next 12 months and certain other specified criteria are met. A business classified as held for sale is recorded at the lower of its carrying amount or estimated fair value less costs of selling. If the carrying amount of the business exceeds its estimated fair value, a loss is recognized. Assets and liabilities related to the businesses classified as held-for-sale are separately reported in our Consolidated Balance Sheets beginning in the period in which the business is classified as held-for-sale. Refer to Note 5 for further information regarding our held-for-sale business. This business was also classified as discontinued operations whose results were aggregated and presented in one line in the consolidated statements of earnings. New Accounting Standards Adopted in 2016 Accounting Standards Update ("ASU") 2016-18, Statement of Cash Flows - Restricted Cash In November 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-18, which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. We have early adopted this guidance and applied it retrospectively to all periods presented on our consolidated financial statements. ASU 2016-17, Consolidation - Interests Held through Related Parties that are under Common Control In October 2016, the FASB issued ASU 2016-17, which amends the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (“VIE”) should treat indirect interests in the entity held through related parties that are under common control

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS 2016 Dana Companies On December 30, 2016, we completed the acquisition of Dana Companies, LLC ("Dana Companies") from Dana Incorporated ("Dana"). Dana Companies holds liabilities associated with personal injury asbestos claims and environmental claims arising from its legacy manufacturing operations. Dana Companies’ assets include, amongst others, insurance rights related to coverage against these liabilities and marketable securities. The total consideration for the transaction was $88.5 million . Purchase price $ 88,500 Net assets acquired at fair value $ 88,500 Excess of purchase price over fair value of net assets acquired $ — The following table summarizes the fair values of the assets acquired and liabilities assumed at the acquisition date, recorded in our Non-life Run-off segment. Total ASSETS Short-term investments, trading, at fair value $ 22,747 Fixed maturities, trading, at fair value 61,389 Other investments, at fair value 46,589 Total investments 130,725 Cash and cash equivalents 58,430 Restricted cash and cash equivalents 1,692 Other assets - Insurance balances recoverable 133,032 Other assets 5,383 TOTAL ASSETS 329,262 LIABILITIES Other liabilities - Asbestos related 220,496 Other liabilities 20,266 TOTAL LIABILITIES 240,762 NET ASSETS ACQUIRED AT FAIR VALUE $ 88,500 From the date of acquisition to December 31, 2016, we did no t record any earnings from Dana Companies. 2015 Nationale Suisse Assurance S.A. On November 13, 2015, we completed the acquisition of Nationale Suisse Assurance S.A. ("NSA"). We changed the name of NSA to Alpha Insurance SA ("Alpha") at closing and placed the company into run-off. Alpha is a Belgium-based composite insurance company that wrote both non-life and life insurance that we are now operating as part of our non-life run-off and life and annuities businesses, respectively. The total consideration for the transaction was €32.8 million (or $35.2 million ). Purchase price $ 35,225 Net assets acquired at fair value $ 35,225 Excess of purchase price over fair value of net assets acquired $ — The following table summarizes the fair values of the assets acquired and liabilities assumed in the Alpha transaction at the acquisition date, allocated by segment. Life and Annuities Non-life Total ASSETS Short-term investments, trading, at fair value $ — $ 8,644 $ 8,644 Short-term investments, available-for-sale, at fair value 6,687 — 6,687 Fixed maturities, trading, at fair value — 31,350 31,350 Fixed maturities, available-for-sale, at fair value 96,656 — 96,656 Other investments, at fair value — 1,339 1,339 Total investments 103,343 41,333 144,676 Cash and cash equivalents 25,258 39,451 64,709 Reinsurance balances recoverable — reserves 302 4,041 4,343 Reinsurance balances recoverable — paids 1,320 10,831 12,151 Prepaid reinsurance premiums — 3,213 3,213 Other assets 2,298 3,097 5,395 TOTAL ASSETS 132,521 101,966 234,487 LIABILITIES Losses and LAE 117,188 56,021 173,209 Funds withheld — 473 473 Insurance and reinsurance balances payable 779 6,212 6,991 Unearned premium — 5,969 5,969 Other liabilities 2,875 9,745 12,620 TOTAL LIABILITIES 120,842 78,420 199,262 NET ASSETS ACQUIRED AT FAIR VALUE $ 11,679 $ 23,546 $ 35,225 From the date of acquisition to December 31, 2015, we earned premiums of $ nil , recorded net incurred losses and LAE of $ nil on those earned premiums, and recorded $0.1 million in net losses attributable to Enstar Group Limited related to Alpha’s business. Wilton Re On May 5, 2015, we completed the acquisition of certain subsidiaries from Wilton Re Limited ("Wilton Re"), which hold in terests in life insurance policies. These interests were acquired by Wilton Re in the secondary and tertiary markets and through collateralized lending transactions. The total consideration for the transaction was $173.1 million , paid in two installments. The first installment of $89.1 million was paid on closing. The second installment of $83.9 million was paid on the first anniversary of closing. The companies are operating as part of the Life and Annuities segment. Purchase price $ 173,058 Net assets acquired at fair value $ 173,058 Excess of purchase price over fair value of net assets acquired $ — The purchase price was allocated to the acquired assets and liabilities of the two companies acquired based on estimated fair values at the acquisition date. The following table summarizes the fair values of the assets acquired and liabilities assumed at the acquisition date. ASSETS Other investments $ 142,182 Cash and cash equivalents 5,043 Other assets 26,376 TOTAL ASSETS $ 173,601 TOTAL LIABILITIES 543 NET ASSETS ACQUIRED AT FAIR VALUE $ 173,058 From the date of acquisition to December 31, 2015, we recorded $16.5 million in net earnings attributable to Enstar Group Limited related to the life settlement contract business. Canada Pension Plan Investment Board ("CPPIB"), together with management of Wilton Re, owns 100% of the common stock of Wilton Re. Subsequent to the closing of our transaction with Wilton Re, CPPIB separately acquired certain of our voting and non-voting ordinary shares in several third party transactions during 2015 and 2016, as described in "Note 21 - Relat ed Party Transactions." Sussex Insurance Company (formerly known as Companion) On January 27, 2015, we completed the acquisition of Companion Property and Casualty Insurance Company ("Companion") from Blue Cross and Blue Shield of South Carolina, an independent licensee of the Blue Cross Blue Shield Association. Companion is a South Carolina based insurance group with property, casualty, specialty and workers ' compensation business, and has also provided fronting and third-party administrative services. We changed the name of Companion to Sussex Insurance Company ("Sussex") following the acquisition, and the company is operating as part of the Non-life Run-off segment. In addition, StarStone is renewing certain business from Sussex. The total consideration for the transaction was $218.0 million , which was financed 50% through borrowings under a Term Facility Agr eement with two financial institutions (the "Sussex Facility") and 50% from cash on hand. Purchase price $ 218,000 Net assets acquired at fair value $ 218,000 Excess of purchase price over fair value of net assets acquired $ — The purchase price was allocated to the acquired assets and liabilities of Sussex based on estimated fair values at the acquisition date. The following table summarizes the fair values of the assets acquired and liabilities assumed at the acquisition date. ASSETS Short-term investments, trading, at fair value $ 85,309 Fixed maturities, trading, at fair value 523,227 Equities, trading, at fair value 31,439 Total investments 639,975 Cash and cash equivalents 358,458 Restricted cash and cash equivalents 15,279 Accrued interest receivable 3,984 Premiums receivable 37,190 Reinsurance balances recoverable 483,816 Prepaid reinsurance premiums 28,751 Other assets 43,939 TOTAL ASSETS 1,611,392 LIABILITIES Losses and LAE 1,257,205 Insurance and reinsurance balances payable 3,030 Unearned premium 79,293 Funds withheld 42,090 Other liabilities 11,774 TOTAL LIABILITIES 1,393,392 NET ASSETS ACQUIRED AT FAIR VALUE $ 218,000 The net unearned premiums acquired included a decrease of $34.6 million to adjust net unearned premiums to fair value. This fair value adjustment is included within unearned premiums on the consolidated balance sheet. As at December 31, 2016 , $16.1 million has been amortized to acquisition costs and $15.7 million has been amortized to net premiums earned in the consolidated statements of earnings and comprehensive income. As at December 31, 2016 , the remaining balance of the fair value adjustment was $2.7 million , which will be amortized to net premiums earned over the remaining terms of the underlying policies. From the date of acquisition to December 31, 2015, we earned premiums of $43.2 million , recorded net incurred losses and LAE of $44.4 million on those earned premiums, and recorded $42.4 million in net losses attributable to Enstar Group Limited related to Sussex’s non-life run-off business. Supplemental Pro Forma Financial Information (Unaudited) The following unaudited pro forma condensed combined statement of earnings for the years ended December 31, 2015 and 2014 combines our historical consolidated statements of earnings with those of Sussex, Alpha and Wilton Re, giving effect to the business combinations and related transactions as if they had occurred on January 1, 2014 and 2015. For the year ended December 31, 2015, the operating results of Sussex, Alpha and Wilton Re have been included in the consolidated financial statements from each of their respective dates of acquisition. The unaudited pro forma financial information presented below is for informational purposes only and is not necessarily indicative of the results of operations that would have been achieved if the acquisitions of Sussex, Alpha and Wilton Re and related transactions had taken place at the beginning of each period presented, nor is it indicative of future results. Enstar Group Unaudited 2015 Sussex Alpha Wilton Re Pro forma Enstar Total income $ 904,460 $ 29,990 $ 31,884 $ 5,793 $ 9,494 $ 981,621 Total expenses (694,119 ) (39,860 ) (47,026 ) (3,628 ) 5,894 (778,739 ) Total noncontrolling interest 9,950 — — — — 9,950 Net earnings (loss) $ 220,291 $ (9,870 ) $ (15,142 ) $ 2,165 $ 15,388 $ 212,832 Summary of the Pro Forma Adjustments to the Pro Forma Condensed Consolidated Statement of Earnings for the Twelve Months Ended December 31, 2015 (Unaudited): Income: (a) Reversal of amortization of fair value adjustments related to unearned premium included in Enstar Group results but reflected in 2014 pro formas 13,344 (b) Adjustment to recognize amortization of fair value adjustments related to unearned premium (3,850 ) 9,494 Expenses: (a) Adjustment to interest expense to reflect financing costs of the acquisition for the period (1,098 ) (b) Adjustment to recognize amortization of fair value adjustments related to acquired losses and LAE liabilities and reinsurance balances recoverable (451 ) (c) Reversal of amortization of fair value adjustments related to acquisition costs included in Enstar Group results but reflected in 2014 pro formas 16,173 (d) Adjustment to income taxes for pro forma adjustments (8,730 ) 5,894 Enstar Group Unaudited 2014 Sussex Alpha Wilton Re Pro forma Enstar Total income $ 710,074 $ 267,939 $ 44,910 $ 17,378 $ (14,557 ) $ 1,025,744 Total expenses (482,838 ) (360,018 ) (52,103 ) (10,884 ) (3,026 ) (908,869 ) Total noncontrolling interest (13,487 ) — — — — (13,487 ) Net earnings (loss) $ 213,749 $ (92,079 ) $ (7,193 ) $ 6,494 $ (17,583 ) $ 103,388 Summary of the Pro Forma Adjustments to the Pro Forma Condensed Consolidated Statement of Earnings for the Twelve Months Ended December 31, 2014 (Unaudited): Income : (a) Adjustment to recognize amortization of fair value adjustments related to unearned premium (14,557 ) Expenses : (a) Adjustment to interest expense to reflect financing costs of the acquisition for the period (5,744 ) (b) Adjustment to recognize amortization of fair value adjustments related to acquired losses and LAE liabilities, deferred acquisition costs and reinsurance balances recoverable (5,417 ) (c) Adjustment to income taxes for pro forma adjustments 8,135 (3,026 ) 2014 StarStone Insurance Bermuda Limited (formerly named Torus Insurance Holdings Limited) On April 1, 2014, we, together with Trident V, L.P., Trident V Parallel Fund, L.P. and Trident V Professionals Fund, L.P., which are managed by Stone Point Capital LLC (collectively, "Trident"), completed the acquisition of Torus In surance Holdings Limited, which we later renamed as StarStone Insurance Bermuda Limited ("StarStone"). StarStone is an A- rated global specialty insurer with six wholly-owned insurance vehicles, including Lloyd’s Syndicate 1301. At closing, StarStone became directly owned by Bayshore Holdings Ltd. ("Bayshore"), which was 60% owned by Kenmare Holdings Ltd., our wholly-owned subsidiary, and 40% owned by Trident. We subsequently renamed Bayshore as StarStone Specialty Holdings Limited ("StarStone Holdings"). The purchase price for StarStone was established in the amended and restated amalgamation agreement as $646.0 million , which was paid partly in cash and partly in our ordinary shares. The number of our shares to be issued was fixed at the signing of the amalgamation agreement on July 8, 2013 and was determined by reference to an agreed-upon value per share of $132.448 , which was the average closing price of our voting ordinary shares, par value $1.00 per share (the "Voting Ordinary Shares"), over the 20 trading days prior to such signing date. On the day before closing of the amalgamation, the Voting Ordinary Shares had a closing price of $136.31 per share. At closing, we contributed cash of $41.6 million towards the purchase price and $3.6 million towards related transaction expenses, as well as 1,898,326 Voting Ordinary Shares and 714,015 shares of our Series B Convertible Participating Non-Voting Perpetual Preferred Stock (the "Non-Voting Preferred Shares"). Based on a price of $136.31 per share, our contribution of cash and shares to the purchase price totaled $397.7 million in the aggregate. Trident contributed cash of $258.4 million towards the purchase price and $2.4 million towards related transaction expenses. Based on a price of $136.31 per share, the aggregate purchase price paid by us and Trident was $656.1 million . As a shareholder of StarStone, FR XI Offshore AIV, L.P., First Reserve Fund XII, L.P., FR XII A Parallel Vehicle L.P. and FR Torus Co-Investment, L.P. (collectively, "First Reserve") received 1,501,211 Voting Ordinary Shares, 714,015 Non-Voting Preferred Shares and cash consideration in the transaction. Following the approval of our shareholders of an amendment to our bye-laws on June 10, 2014, First Reserve’s Non-Voting Preferred Shares converted on a share-for-share basis into 714,015 shares of newly created Series E Non-Voting Convertible Common Shares (the "Series E Non-Voting Ordinary Shares"). Corsair Specialty Investors, L.P. ("Corsair") received 397,115 Voting Ordinary Shares and cash consideration in the transaction. The remaining StarStone shareholders received all cash. Upon the closing of the transaction, StarStone Holdings, Kenmare and Trident entered into a Shareholders’ Agreement (the "StarStone Holdings Shareholders’ Agree ment"), which was subsequently amended, as described in "Changes in Ownership Interests relating to Holding Companies for our Active Underwriting Businesses" below. Purchase price $ 656,088 Net assets acquired at fair value $ 643,088 Excess of purchase price over fair value of net assets acquired $ 13,000 The purchase price was allocated to the acquired assets and liabilities of StarStone based on estimated fair values at the acquisition date. We recognized goodwill of $13.0 million , primarily attributable to StarStone’s assembled workforce. We also recognized indefinite lived intangible assets of $23.9 million and other definite lived intangible assets of $20.0 million . Prior to acquisition, StarStone ceased underwriting certain lines of business in order to focus on core property, casualty and specialty lines. The results of the discontinued lines of business that were placed into run-off are included within our Non-life Run-off segment. The following table summarizes the fair values of the assets acquired and liabilities assumed in the StarStone transaction at the acquisition date, allocated by segment. StarStone Segment Non-life Run-off Segment Total ASSETS Short-term investments, trading, at fair value $ 73,425 $ 25,888 $ 99,313 Fixed maturities, trading, at fair value 736,765 329,235 1,066,000 Other investments 2,068 — 2,068 Total investments 812,258 355,123 1,167,381 Cash and cash equivalents 211,718 127,890 339,608 Restricted cash and cash equivalents 22,779 — 22,779 Premiums receivable 321,350 — 321,350 Reinsurance balances recoverable — reserves 210,742 152,057 362,799 Reinsurance balances recoverable — paids 21,122 20,100 41,222 Prepaid reinsurance premiums 144,221 25,221 169,442 Intangible assets 43,900 — 43,900 Other assets 37,621 — 37,621 TOTAL ASSETS 1,825,711 680,391 2,506,102 LIABILITIES Losses and LAE 675,424 588,822 1,264,246 Insurance and reinsurance balances payable 140,997 42,447 183,444 Unearned premium 343,840 49,122 392,962 Other liabilities 22,362 — 22,362 TOTAL LIABILITIES 1,182,623 680,391 1,863,014 NET ASSETS ACQUIRED AT FAIR VALUE 643,088 — 643,088 Goodwill 13,000 — 13,000 ACQUISITION DATE FAIR VALUE $ 656,088 $ — $ 656,088 The net unearned premiums acquired included a decrease of $11.1 million to adjust net unearned premiums to fair value. This fair value adjustment is included within unearned premiums on the consolidated balance sheet. As at December 31, 2016, the full amount of $11.1 million had been amortized in the consolidated statements of earnings and comprehensive income. The foll owing table summarizes the intangible assets recorded in connection with the acquisition: Amount Economic Useful Life Syndicate capacity $ 4,000 Indefinite U.S. insurance licenses 19,900 Indefinite Technology 15,000 4 Years Brand 5,000 6 Years Intangible assets as of the acquisition date $ 43,900 The fair value of the Lloyd’s syndicate capacity was estimated using the multi-period excess-earnings method, a form of the income approach. Lloyd’s syndicate capacity represents StarStone’s authorized premium income limit to write insurance business in the Lloyd’s market. The capacity is renewed annually at no cost to us but may be freely purchased or sold, subject to Lloyd’s approval. The ability to write insurance business within the syndicate capacity is indefinite, with the premium income limit being set annually by StarStone, subject to Lloyd’s approval. U.S. insurance licenses represent the intangible asset related to StarStone’s licenses and have been valued based on recent market transactions. Technology represents the intangible asset related to StarStone’s capitalized software and has been valued on a replacement cost basis. Brand represents the intangible asset related to the Torus name and was valued using the income approach. This was subsequently written off during 2015 when Torus was renamed as StarStone. Supplemental Pro Forma Financial Information (Unaudited) The operating results for StarStone have been included in the consolidated financial statements from the date of acquisition. The following pro forma condensed combined statement of earnings for the years ended December 31, 2014 combines our historical consolidated statements of earnings with the historical consolidated statements of earnings of StarStone, giving effect to the business combinations and related transactions as if they had occurred on January 1, 2014. The unaudited pro forma financial information presented below is for informational purposes only and is not necessarily indicative of the results of operations that would have been achieved if the acquisition of StarStone and related transactions had taken place at the beginning of each period presented, nor is it indicative of future results. Enstar Group Limited Unaudited 2014 StarStone Proforma Adjustments Enstar Group Limited - Proforma Total income $ 710,074 $ 147,193 $ (1,846 ) $ 855,421 Total expenses (482,838 ) (145,479 ) 3,670 (624,647 ) Total noncontrolling interest (13,487 ) — (1,451 ) (14,938 ) Net earnings $ 213,749 $ 1,714 $ 373 $ 215,836 Summary of the Pro Forma Adjustments to the Pro Forma Condensed Consolidated Statement of Earnings for the Twelve Months Ended December 31, 2014 (Unaudited): Income : (a) Adjustment to recognize amortization of fair value adjustments related to unearned premium (1,846 ) Expenses : (a) Adjustment to recognize amortization of definite-lived intangible assets (1,146 ) (b) Adjustment to recognize amortization of fair value adjustments related to acquired losses and loss adjustment expense liabilities and reinsurance balances recoverable 4,816 3,670 (c) Adjustment to noncontrolling interest for pro forma condensed consolidated statement of earnings (1,451 ) Changes in Ownership Interests relating to Holding Companies for our Active Underwriting Businesses Corporate Holding Company Reorganization during 2015 On December 23, 2015, we completed a corporate reorganization of certain of our subsidiary holding companies. Following the reorganization, StarStone Holdings and Northshore are owned by a common parent, North Bay Holdings Limited ("North Bay"), as described in Note 16 - "Noncontrolling Interests". Dowling Co-investments during 2014 On May 8, 2014, Dowling Capital Partners I, L.P. ("Dowling") purchased common shares of both StarStone Holdings and Northshore from Kenmare and Trident (on a pro rata basis in accordance with their respective interests) for an aggregate amount of $15.4 million . Prior to the sale of shares to Dowling, Kenmare and Trident owned 60% and 40% of StarStone Holdings and Northshore, respectively. Following the sale Kenmare, Trident and Dowling owned 59.0% , 39.3% and 1.7% , respectively, of StarStone Holdings and Northshore. The shareholders’ agreements governing North Bay, StarStone Holdings and Northshore, among other things, provide that Kenmare has the right to appoint three members to the StarStone Holdings board of directors and Trident has the right to appoint two members. The shareholders’ agreements also include redemption rights and obligations which are described in Note 23 - "Commitments and Contingencies."

Significant New Business

Significant New Business	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Significant New Business	SIGNIFICANT NEW BUSINESS 2017 RSA On February 7, 2017, we entered into an agreement to reinsure U.K. employers' liability legacy business of RSA Insurance Group PLC ("RSA"). Pursuant to the transaction, our subsidiary will assume gross insurance reserves of approximately £957 million (approximately $1.2 billion ), relating to 2005 and prior year business. Net insurance reserves are approximately £834 million (approximately $1.0 billion ) a nd the reinsurance premium payable to Enstar’s subsidiary is £799 million (approximately $1.0 billion ) . The transaction is subject to finalizing and effecting certain security arrangements. Following the initial reinsurance transaction, which will transfer the economics of the portfolio up to the policy's limits, we and RSA will pursue a portfolio transfer of the business under Part VII of the Financial Services and Markets Act 2000, which would provide legal finality for RSA's obligations. The transfer is subject to court, regulatory and other approvals. QBE On January 11, 2017, we announced the closing of a transaction to reinsure multi-line property and casualty business of QBE Insurance Group Limited ("QBE"). Our subsidiary assumed gross reinsurance reserves of approximately $919.0 million (net reserves of $444.0 million ) relating to the portfolio, which primarily includes workers' compensation, construction defect, and general liability discontinued lines of business. In addition our subsidiary has pledged a portion of the premium as collateral to a subsidiary of QBE, and we have provided additional collateral and a limited parental guarantee. 2016 Coca-Cola On August 5, 2016, we entered into a reinsurance transaction with The Coca-Cola Company and its subsidiaries (“Coca-Cola”) pursuant to which we reinsured certain of Coca-Cola’s retention and deductible risks under its subsidiaries’ U.S. workers’ compensation, auto liability, general liability, and product liability insurance coverage. We assumed total gross reserves of $108.8 million , received total assets of $101.3 million and recorded a deferred charge of $7.5 million , included in other assets. We have transferred $108.8 million into a trust to support our obligations under the reinsurance agreements. We provided a limited parental guarantee, subject to an overall maximum of $27.0 million . Allianz On February 17, 2016, we entered into a reinsurance agreement with Allianz SE ("Allianz") to reinsure portfolios of Allianz's run-off business. Pursuant to the reinsurance agreement, our subsidiary reinsured 50% of certain portfolios of workers' compensation, construction defect, and asbestos, pollution, and toxic tort business originally held by Fireman's Fund Insurance Company, and in the process assumed net reinsurance reserves of $1.1 billion . Affiliates of Allianz retained $1.1 billion of reinsurance premium as funds withheld collateral for the obligations of our subsidiary under the reinsurance agreement and we transferred $110.0 million to a reinsurance trust to further support our subsidiary's obligations. We have also provided a limited parental guarantee, which is subject to a maximum cap. The combined monetary total of the support offered by us through the trust and parental guarantee was initially be capped at $270.0 million . In addition to the reinsurance transaction described above, we have entered into a consulting agreement with San Francisco Reinsurance Company, an affiliate of Allianz, with respect to the entire $2.2 billion portfolio, including the 50% share retained by affiliates of Allianz. Shelbourne RITC Transaction On November 15, 2016, we entered into a RITC transaction of the 2007 and prior underwriting years of account of a Lloyd’s syndicate managed by Neon (formerly Marketform), under which we assumed total net insurance reserves of £121.5 million ( $158.0 million ) for cash consideration of an equal amount. 2015 Doctors On November 30, 2015, we completed the assignment and assumption of a portfolio of primarily workers' compensation business from The Doctors Company and its affiliates. Total assets and liabilities assumed were $29.5 million . Sun Life On September 30, 2015, we entered into two 100% reinsurance agreements and a related administration services agreement with Sun Life pursuant to which we reinsured all of the run-off workers' compensation carve-out and occupational accident business of Sun Life. We assumed reinsurance reserves of $128.3 million , received total assets of $122.5 million and recorded a deferred charge of $5.8 million , included in other assets. We transferred $30.6 million of additional funds into trust to further support our obligations under the reinsurance agreements. We provided limited parental guarantees, subject to an overall maximum of $36.8 million . Voya Financial On May 27, 2015, we entered into two 100% reinsurance agreements and related administration services agreements with a subsidiary of Voya, pursuant to which we reinsured all of the run-off workers' compensation and occupational accident assumed reinsurance business of the Voya subsidiary and that of its Canadian branch. Pursuant to the transaction, the Voya subsidiary transferred assets into two reinsurance collateral trusts securing our obligations under the reinsurance agreements. We assumed reinsurance reserves of $572.4 million , received total assets of $307.0 million and recorded a deferred charge of $265.4 million , included in other assets. We transferred $67.2 million of additional funds to the trusts to further support our obligations under the reinsurance agreements. We provided a limited parental guarantee, subject to a maximum cap with respect to the reinsurance liabilities. As of December 31, 2016 , the amount of the parental guarantee was $58.0 million . Reciprocal of America On January 15, 2015 , we completed a loss portfolio transfer reinsurance transaction with Reciprocal of America (in Receivership) and its Deputy Receiver relating to a portfolio of workers' compensation business that has been in run-off since 2003. The total insurance reserves assumed were $162.1 million with an equivalent amount of cash and investments received as consideration. 2014 Shelbourne RITC Transaction On January 1, 2014, we entered into a RITC of the 2011 and prior underwriting years of account of a Lloyd’s syndicate, under which we assumed total net insurance reserves of £17.0 million ( $28.1 million ) for cash consideration of an equal amount.

Held-For-Sale Business

Held-For-Sale Business	12 Months Ended
	Dec. 31, 2016
Discontinued Operations and Disposal Groups [Abstract]
Held-For-Sale Business	HELD-FOR-SALE BUSINESS On February 17, 2017, we entered into a definitive agreement to sell Pavonia Holdings (US) Inc. and its subsidiaries (“Pavonia”) for total consideration of $120.0 million to Southland National Holdings, Inc. The transaction is expected to close in the third or fourth quarter of 2017. The closing of the transaction is subject to customary closing conditions, including regulatory approvals. The proceeds of the sale are expected to be used to pay down our revolving credit facility following closing. Pavonia is a substantial portion of the Life and Annuities segment. We have classified the assets and liabilities of the businesses to be sold as held-for-sale. The following table summarizes the components of assets and liabilities held-for-sale on our consolidated balance sheet as at December 31, 2016 and 2015: December 31, December 31, Assets: Short-term investments, trading, at fair value $ — $ 2,246 Fixed maturities, trading, at fair value 326,382 262,273 Fixed maturities, held-to-maturity, at amortized cost 765,554 790,866 Equities, trading, at fair value 4,428 4,446 Other investments, at fair value 15,114 53,743 Cash and cash equivalents 18,018 26,680 Restricted cash and cash equivalents 5,202 11,415 Deferred tax assets 31,500 31,531 Reinsurance balances recoverable 18,029 22,083 Other assets 60,229 64,300 Total assets held for sale $ 1,244,456 $ 1,269,583 Liabilities: Policy benefits for life and annuity contracts $ 1,144,850 $ 1,178,376 Other liabilities 5,937 11,083 Total liabilities held for sale $ 1,150,787 $ 1,189,459 As of December 31, 2016 and 2015 , included in the table above were restricted investments of $786.0 million and $804.2 million , respectively. The cumulative currency translation adjustment ("CTA") balance in accumulated other comprehensive income (loss), a component of shareholders’ equity, included $(14.8) million as at December 31, 2016 related to Pavonia. Upon completion of the sale, the CTA will be included in earnings as a reduction of the gain on sale. The Pavonia business qualifies as a discontinued operation. The following table summarizes the components of net earnings (losses) from discontinued operations on the consolidated statements of earnings for the years ended December 31, 2016, 2015 and 2014: December 31, December 31, December 31, INCOME Net premiums earned $ 69,089 $ 85,327 $ 103,459 Net investment income 38,140 35,404 36,599 Net realized and unrealized gains (losses) 4,263 271 10,628 Other income 1,912 7,690 1,813 $ 113,404 $ 128,692 $ 152,499 EXPENSES Life and annuity policy benefits 76,594 97,472 107,962 Acquisition costs 9,836 13,712 15,031 General and administrative expenses 14,416 13,886 17,206 Other expenses 199 486 1,220 $ 101,045 $ 125,556 $ 141,419 EARNINGS (LOSS) BEFORE INCOME TAXES 12,359 3,136 11,080 INCOME TAXES (396 ) $ (5,167 ) (5,541 ) NET EARNINGS FROM DISCONTINUED OPERATIONS $ 11,963 $ (2,031 ) $ 5,539 The following table presents the cash flows of Pavonia for the years ended December 31, 2016, 2015 and 2014: December 31, December 31, December 31, Operating activities $ (71,521 ) $ (5,893 ) $ (46,386 ) Investing activities 56,646 (24,766 ) 32,641 Financing Activities — — — Change in cash of businesses held for sale $ (14,875 ) $ (30,659 ) $ (13,745 )

Investments

Investments	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS We hold: (i) trading portfolios of fixed maturity investments, short-term investments and equities, carried at fair value; (ii) available-for-sale portfolios of fixed maturity and short-term investments carried at fair value; and (iii) other investments carried at either fair value or cost. Trading The fair values of our fixed maturity investments, short-term investments and equities classified as trading were as follows: December 31, December 31, U.S. government and agency $ 840,274 $ 742,918 Non-U.S. government 267,363 338,170 Corporate 2,387,322 2,564,618 Municipal 47,181 22,247 Residential mortgage-backed 373,528 381,573 Commercial mortgage-backed 217,212 232,847 Asset-backed 478,280 531,252 Total fixed maturity and short-term investments 4,611,160 4,813,625 Equities — U.S. 95,047 108,793 Equities — International — 2,702 $ 4,706,207 $ 4,925,120 Included within residential and commercial mortgage-backed securities as at December 31, 2016 were securities issued by U.S. governmental agencies with a fair value of $362.9 million (as at December 31, 2015 : $355.4 million ). Included within corporate securities as at December 31, 2016 were senior secured loans of $90.7 million (as at December 31, 2015 : $94.4 million ). The contractual maturities of our fixed maturity and short-term investments classified as trading 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 o r prepayment penalties. As at December 31, 2016 Amortized Cost Fair Value % of Total Fair Value One year or less $ 748,634 $ 739,820 16.0 % More than one year through two years 713,175 708,739 15.4 % More than two years through five years 1,270,909 1,259,564 27.3 % More than five years through ten years 651,539 648,156 14.1 % More than ten years 186,066 185,861 4.0 % Residential mortgage-backed 378,516 373,528 8.1 % Commercial mortgage-backed 220,727 217,212 4.7 % Asset-backed 476,595 478,280 10.4 % $ 4,646,161 $ 4,611,160 100.0 % Available-for-sale The amortized cost and fair values of our fixed maturity and short-term investments classified as available-for-sale were as follows: As at December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Non-OTTI Fair Value U.S. government and agency $ 12,784 $ 32 $ (106 ) $ 12,710 Non-U.S. government 86,897 1,303 (2,777 ) 85,423 Corporate 159,243 2,040 (2,628 ) 158,655 Municipal 6,585 12 (21 ) 6,576 Residential mortgage-backed 488 39 — 527 Asset-backed 3,867 9 — 3,876 $ 269,864 $ 3,435 $ (5,532 ) $ 267,767 As at December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Non-OTTI Fair Value U.S. government and agency $ 25,102 $ 80 $ (341 ) $ 24,841 Non-U.S. government 89,631 42 (3,889 ) 85,784 Corporate 182,773 1,040 (3,429 ) 180,384 Municipal 5,959 4 (36 ) 5,927 Residential mortgage-backed 665 51 (1 ) 715 Asset-backed 4,660 — (10 ) 4,650 $ 308,790 $ 1,217 $ (7,706 ) $ 302,301 The contractual maturities of our fixed maturity and short-term investments classified as available-for-sale 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 at December 31, 2016 Amortized Cost Fair Value % of Total Fair Value One year or less $ 48,561 $ 46,955 17.5 % More than one year through two years 62,855 61,395 22.9 % More than two years through five years 72,008 70,404 26.3 % More than five years through ten years 43,889 45,173 16.9 % More than ten years 38,196 39,437 14.7 % Residential mortgage-backed 488 527 0.2 % Asset-backed 3,867 3,876 1.5 % $ 269,864 $ 267,767 100.0 % Gross Unrealized Losses The following tables summarize our fixed maturity and short-term investments in a gross unrealized loss position: 12 Months or Greater Less Than 12 Months Total As at December 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturity and short-term investments, at fair value U.S. government and agency $ — $ — $ 10,743 $ (106 ) $ 10,743 $ (106 ) Non-U.S. government 8,316 (1,794 ) 30,086 (983 ) 38,402 (2,777 ) Corporate 8,003 (1,800 ) 42,304 (828 ) 50,307 (2,628 ) Municipal — — 3,132 (21 ) 3,132 (21 ) Total fixed maturity and short-term investments $ 16,319 $ (3,594 ) $ 86,265 $ (1,938 ) $ 102,584 $ (5,532 ) 12 Months or Greater Less Than 12 Months Total As at December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturity and short-term investments, at fair value U.S. government and agency $ 523 $ (2 ) $ 21,694 $ (339 ) $ 22,217 $ (341 ) Non-U.S. government 18,995 (2,633 ) 50,080 (1,256 ) 69,075 (3,889 ) Corporate 54,295 (2,394 ) 81,047 (1,035 ) 135,342 (3,429 ) Municipal — — 4,609 (36 ) 4,609 (36 ) Residential mortgage-backed 71 (1 ) — — 71 (1 ) Asset-backed 4,649 (10 ) — — 4,649 (10 ) Total fixed maturity and short-term investments $ 78,533 $ (5,040 ) $ 157,430 $ (2,666 ) $ 235,963 $ (7,706 ) As at December 31, 2016 and December 31, 2015 , the number of securities classified as available-for-sale in an unrealized loss position was 156 and 332 , respectively. Of these securities, the number of securities that had been in an unrealized loss position for twelve months or longer was 41 and 124 , respectively. Other-Than-Temporary Impairment For the years ended December 31, 2016 , and 2015, we did no t recognize any other-than-temporary impairment losses on our available-for-sale securities. We determined that no credit losses existed as at December 31, 2016 and 2015. A description of our other-than-temporary impairment process is included in Note 2 - "Significant Accounting Policies." There were no changes to our process in the years ended December 31, 2016 , and 2015. Credit Ratings The following table sets forth the credit ratings of our fixed maturity and short-term investments as of December 31, 2016 : Amortized Cost Fair Value % of Total Investments AAA Rated AA Rated A Rated BBB Rated Non- Investment Grade Not Rated U.S. government and agency $ 857,530 $ 852,984 17.5 % $ 846,698 $ 6,286 $ — $ — $ — $ — Non-U.S. government 362,797 352,786 7.2 % 140,357 150,569 43,771 18,089 — — Corporate 2,561,305 2,545,977 52.2 % 105,081 465,224 1,199,452 615,538 149,898 10,784 Municipal 54,200 53,757 1.1 % 25,566 25,834 2,357 — — — Residential mortgage-backed 379,004 374,055 7.7 % 370,067 403 3,487 — 97 1 Commercial mortgage-backed 220,727 217,212 4.4 % 100,065 41,542 41,837 16,383 77 17,308 Asset-backed 480,462 482,156 9.9 % 213,312 58,322 114,503 23,534 72,485 — Total $ 4,916,025 4,878,927 100.0 % 1,801,146 748,180 1,405,407 673,544 222,557 28,093 % of total fair value 36.9 % 15.3 % 28.8 % 13.8 % 4.6 % 0.6 % Other Investments, at fair value The following table summarizes our other investments carried at fair value: December 31, December 31, Private equities and private equity funds $ 300,529 $ 232,372 Fixed income funds 249,023 280,749 Fixed income hedge funds 85,976 89,154 Equity funds 223,571 147,390 Multi-strategy hedge fund — 99,020 Real estate debt fund — 54,829 CLO equities 61,565 61,702 CLO equity funds 15,440 13,928 Other 943 1,145 $ 937,047 $ 980,289 The valuation of our other investments is described in Note 8 - "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: • Private equities and private equity funds invest primarily in the financial services industry. All of our investments in private equities and private equity funds are subject to restrictions on redemptions and sales that are determined by the governing documents and limit our ability to liquidate those investments. These restrictions have been in place since the dates of our initial investments. • Fixed income funds comprise a number of positions in diversified fixed income funds that are managed by third-party managers. Underlying investments vary from high-grade corporate bonds to non-investment grade senior secured loans and bonds, but are generally invested in liquid fixed income markets. These funds have regularly published prices. The funds have liquidity terms that vary from daily up to quarterly. • Fixed income hedge funds invest in a diversified portfolio of debt securities. The hedge funds have imposed lock-up periods of up to three years from the time of initial investment. Once eligible, redemptions will be permitted quarterly with 90 days’ notice. • Equity funds invest in a diversified portfolio of international publicly traded equity securities. The funds have liquidity terms that vary from daily to bi-monthly. • Multi-strategy hedge fund was an investment in a hedge fund that invested in a variety of asset classes including funds, fixed income, equity securities and other investments. The fund was sold in December 2016. The proceeds of sale were contributed to our investment in the start-up reinsurer KaylaRe Holdings, which is recorded as an equity-method investment in other assets on our consolidated balance sheet. • Real estate debt fund invests primarily in U.S. commercial real estate loans and securities. A redemption request for this fund can be made 10 days after the date of any monthly valuation. The fund was fully redeemed during the year ended December 31, 2016. • CLO equities comprise investments in the equity tranches of term-financed securitizations of diversified pools of corporate bank loans. CLO equities denote direct investments by us in these securities. • CLO equity funds comprise two funds that invest primarily in the equity tranches of term-financed securitizations of diversified pools of corporate bank loans. One of the funds has a fair value of $4.1 million , part of a self-liquidating structure which is expected to pay out over one to five years. The other fund has a fair value of $11.3 million and is eligible for redemption in 2018. • Other primarily comprises a fund that provides loans to educational institutions throughout the United States and its territories. Investments of $0.5 million in fixed income hedge funds were subject to gates or side-pockets, where redemptions are subject to the sale of underlying investments. 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. As at December 31, 2016 , we had unfunded commitments to private equity funds of $144.0 million . Other Investments, at cost Our other investments carried at cost of $131.7 million as of December 31, 2016 consist of life settlement contracts acquired during 2015. Refer to Note 3 - "Acquisitions" for information about this transaction, and Note 2 - "Significant Accounting Policies" for a description of our accounting policies. During the years ended December 31, 2016 and 2015 , net investment income included $18.0 million and $20.1 million respectively, related to investments in life settlements. During the years ended December 31, 2016 and 2015 , there were impairment charges of $5.3 million and nil respectively, recognized in net realized and unrealized gains/losses. The following table presents further information regarding our investments in life settlements as of December 31, 2016 and 2015 . December 31, 2016 December 31, 2015 Number of Contracts Carrying Face Value (Death Benefits) Number of Contracts Carrying Face Value (Death Benefits) Remaining Life Expectancy of Insureds: 0 – 1 year 2 $ 461 $ 700 2 $ 417 $ 700 1 – 2 years 7 11,396 18,337 4 3,032 5,000 2 – 3 years 11 15,338 29,715 19 24,072 39,123 3 – 4 years 17 17,013 32,189 14 9,695 20,932 4 – 5 years 16 10,377 23,302 16 9,025 22,457 Thereafter 181 77,066 431,034 221 86,830 491,499 Total 234 $ 131,651 $ 535,277 276 $ 133,071 $ 579,711 Remaining life expectancy for year 0-1 in the table above references policies whose current life expectancy is less than 12 months as of the reporting date. Remaining life expectancy is not an indication of expected maturity. Actual maturity in any category above may vary significantly (either earlier or later) from the remaining life expectancies reported. At December 31, 2016 , our best estimate of the life insurance premiums required to keep the policies in force, payable in the 12 months ending December 31, 2017 and the four succeeding years ending December 31, 2021 is $17.8 million , $17.5 million , $17.7 million , $16.9 million , and $15.6 million , respectively. Net Realized and Unrealized Gains (Losses) Components of net realized and unrealized gains (losses) for the years ended December 31, 2016 , 2015 and 2014 were as follows: 2016 2015 2014 Net realized gains (losses) on sale: Gross realized gains on fixed maturity securities, available-for-sale $ 405 $ 396 $ 196 Gross realized (losses) on fixed maturity securities, available-for-sale securities (21 ) (130 ) (138 ) Net realized investment gains (losses) on fixed maturity securities, trading 1,848 (4,291 ) 3,372 Net realized investment gains on equity securities, trading 5,348 19,884 18,738 Net realized investment losses on funds held - directly managed (14,616 ) — — Total net realized gains (losses) on sale (7,036 ) 15,859 22,168 Net unrealized gains (losses): Fixed maturity securities, trading 36,314 (52,918 ) 9,890 Equity securities, trading 6,561 (21,875 ) (8,665 ) Other investments 70,296 17,411 28,598 Change in fair value of embedded derivative on funds held – directly managed (28,317 ) — — Total net unrealized gains (losses) 84,854 (57,382 ) 29,823 Net realized and unrealized gains (losses) $ 77,818 $ (41,523 ) $ 51,991 The gross realized gains and losses on available-for-sale securities included in the table above resulted from sales of $41.3 million , $95.1 million and $90.7 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. Net Investment Income Major categories of net investment income for the years ended December 31, 2016 , 2015 and 2014 are summarized as follows: 2016 2015 2014 Fixed maturity investments $ 114,885 $ 87,512 $ 58,815 Short-term investments and cash and cash equivalents 4,491 5,993 6,209 Equity securities 4,874 5,580 5,671 Other investments 22,515 11,712 1,335 Funds held 22,583 234 1,376 Funds held – directly managed 5,769 — — Life settlements and other 18,191 20,871 593 Gross investment income 193,308 131,902 73,999 Investment expenses (7,845 ) (9,338 ) (7,975 ) Net investment income $ 185,463 $ 122,564 $ 66,024 Restricted Assets We are required to maintain investments and cash and cash equivalents on deposit to support our insurance and reinsurance operations. The investments and cash and cash equivalents on deposit are available to settle insurance and reinsurance liabilities. We also utilize trust accounts to collateralize business with our insurance and reinsurance counterparties. These trust accounts generally take the place of letter of credit requirements. The assets in trusts as collateral are primarily highly rated fixed maturity securities. The carrying value of our restricted assets, including restricted cash of $363.8 million and $499.9 million , as of December 31, 2016 and 2015 , respectively, was as follows: December 31, December 31, Collateral in trust for third party agreements $ 1,975,022 $ 1,993,065 Assets on deposit with regulatory authorities 882,400 906,973 Collateral for secured letter of credit facilities 177,263 212,544 Funds at Lloyd's (1) 220,328 382,624 $ 3,255,013 $ 3,495,206 (1) Our underwriting 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. In November 2016, we entered into an unsecured letter of credit agreement for Funds at Lloyd’s purposes ("FAL Facility") to issue up to $140.0 million of letters of credit, with a provision to increase the facility up to $200.0 million . The FAL Facility is available to satisfy our Funds at Lloyd’s requirements and replaces certain restricted assets and letter of credit arrangements. The FAL Facility expires in 2021. As at December 31, 2016 , our combined Funds at Lloyd's were comprised of cash and investments of $220.3 million and unsecured letters of credit of $122.0 million .

Funds Held - Directly Managed

Funds Held - Directly Managed	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
FUNDS HELD - DIRECTLY MANAGED	FUNDS HELD - DIRECTLY MANAGED On October 1, 2016, the funds held balance in relation to the Allianz transaction, described in Note 4 - "Significant New Business", moved from a fixed crediting rate to a variable rate of return on the underlying investments. This variable return reflects the economics of the investment portfolio underlying the funds held asset and qualifies as an embedded derivative. We have recorded the aggregate of the funds held, typically held at cost, and the embedded derivative as a single amount in our consolidated balance sheet. As at December 31, 2016, the funds held at cost had a carrying value of $1,023.0 million and the embedded derivative had a fair value of ($28.3) million , the aggregate of which was $994.7 million , as reflected in the table below. The carrying values of assets and liabilities underlying the funds held - directly managed account as at December 31, 2016 were as follows: December 31, Fixed maturity investments: U.S. government and agency $ 47,885 Non-U.S. government 5,961 Corporate 663,556 Municipal 38,927 Commercial mortgage-backed 151,395 Asset-backed 79,806 Total fixed maturity investments $ 987,530 Other assets $ 7,135 $ 994,665 The contractual maturities of our fixed maturity investments underlying the funds held - directly managed account 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 at December 31, 2016 Amortized Cost Fair Value % of Total Fair Value One year or less $ 5,027 $ 5,026 0.5 % More than one year through two years 20,641 20,613 2.1 % More than two years through five years 301,119 296,685 30.0 % More than five years through ten years 253,811 244,967 24.9 % More than ten years 197,236 189,038 19.1 % Commercial mortgage-backed 158,129 151,395 15.3 % Asset-backed 79,885 79,806 8.1 % $ 1,015,848 $ 987,530 100.0 % Credit Ratings The following table sets forth the credit ratings of our fixed maturity investments underlying the funds held - directly managed account as of December 31, 2016 . Amortized Cost Fair Value % of Total Investments AAA Rated AA Rated A Rated BBB Rated U.S. government and agency $ 50,257 $ 47,885 4.9 % $ 47,885 $ — $ — $ — Non-U.S. government 6,020 5,961 0.6 % — — 2,913 3,048 Corporate 681,484 663,556 67.2 % 5,549 63,809 234,975 359,223 Municipal 40,073 38,927 3.9 % — 12,839 26,088 — Commercial mortgage-backed 158,129 151,395 15.3 % 146,429 3,015 1,951 — Asset-backed 79,885 79,806 8.1 % 76,130 3,676 — — Total $ 1,015,848 $ 987,530 100.0 % $ 275,993 $ 83,339 $ 265,927 $ 362,271 % of total fair value 28.0 % 8.4 % 26.9 % 36.7 % Net Realized Gains (Losses) and Change in Fair Value of Embedded Derivative Net realized and unrealized gains (losses) and change in fair value of embedded derivative for the year ended December 31, 2016 are summarized as follows: 2016 Net realized gains (losses) on fixed maturity securities $ (14,616 ) Change in fair value of embedded derivative (28,317 ) Net realized gains (losses) and change in fair value of embedded derivative $ (42,933 ) Net Investment Income Major categories of net investment income underlying the funds held - directly managed for the year ended December 31, 2016 are summarized as follows: 2016 Fixed maturity investments $ 5,705 Short-term investments and cash and cash equivalents 64 Investment income on funds held - directly managed $ 5,769

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	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 pricin g sources or management's assumptions and internal valuation models may be used to determine the fair values. We have categorized our investments that are recorded at fair value on a recurring basis among levels based on the observability of inputs as follows: December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Investments: U.S. government and agency $ — $ 852,984 $ — $ 852,984 Non-U.S. government — 352,786 — 352,786 Corporate — 2,471,444 74,534 2,545,978 Municipal — 53,757 — 53,757 Residential mortgage-backed — 374,055 — 374,055 Commercial mortgage-backed — 204,999 12,213 217,212 Asset-backed — 467,463 14,692 482,155 Equities — U.S. 91,287 3,760 — 95,047 Other investments — 357,438 76,878 434,316 $ 91,287 $ 5,138,686 $ 178,317 $ 5,408,290 Funds Held - Directly Managed: U.S. government and agency $ — $ 47,885 $ — $ 47,885 Non-U.S. government — 5,961 — 5,961 Corporate — 663,556 — 663,556 Residential mortgage-backed — 38,927 — 38,927 Commercial mortgage-backed — 151,395 — 151,395 Asset-backed — 79,806 — 79,806 Other assets — 7,135 — 7,135 $ — $ 994,665 $ — $ 994,665 Other Assets: Derivative Instruments $ — $ 2,930 $ — $ 2,930 $ — $ 2,930 $ — $ 2,930 Other Liabilities: Derivative Instruments $ — $ 74 $ — $ 74 $ — $ 74 $ — $ 74 December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Investments: U.S. government and agency $ — $ 767,759 $ — $ 767,759 Non-U.S. government — 423,954 — 423,954 Corporate — 2,745,002 — 2,745,002 Municipal — 28,174 — 28,174 Residential mortgage-backed — 382,288 — 382,288 Commercial mortgage-backed — 206,143 26,704 232,847 Asset-backed — 415,462 120,440 535,902 Equities — U.S. 99,467 9,326 — 108,793 Equities — International 2,702 — — 2,702 Other investments — 321,076 77,016 398,092 Total investments $ 102,169 $ 5,299,184 $ 224,160 $ 5,625,513 Certain of our other investments are measured at fair value using NAV per share (or its equivalent) as a practical expedient and have not been classified within the fair value hierarchy above. The following table reconciles our other investments in the tables above with the amounts presented on our consolidated balance sheets: Other investments: December 31, 2016 December 31, 2015 Other investments measured at fair value $ 434,316 $ 398,092 Other investments measured at NAV as practical expedient 502,731 582,197 Total other investments shown on balance sheets $ 937,047 $ 980,289 Valuation Methodologies of Financial Instruments Measured at Fair Value Fixed Maturity Investments The fair values for all securities in the 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 in 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 such other inputs as are available from market sources to determine a reasonable fair value. In addition, pricing services use valuation models, using observable data, such as an Option Adjusted Spread model, to develop prepayment and interest rate scenarios. The Option Adjusted Spread model is commonly used to estimate fair value for securities such as mortgage-backed and asset-backed securities. The following describes the techniques generally used to determine the fair value of our 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 are predominantly traded on the major exchanges and are primarily managed by our external advisors. We use an internationally recognized pricing service to estimate the fair value of our equities. Our equities are widely diversified and there is no significant concentration in any specific industry. We have categorized all of our investments in equities other than preferred stock as Level 1 investments because the fair values of these investments are based on unadjusted quoted prices in active markets for identical assets or liabilities. The fair value estimates of our investments in 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 private equities and 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. • 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 fixed income and multi-strategy 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. In December 2016, we sold the multi-strategy hedge fund. • Our investment in the real estate debt fund was valued based on the most recently available NAV from the external fund manager. The fair value of this investment was measured using the NAV practical expedient and therefore has not been categorized within the fair value hierarchy. This fund was fully redeemed during the year ended December 31, 2016. • We measure the fair value of our direct investment in CLO equities based on valuations provided by our external CLO equity manager. If the investment does not involve an external CLO equity manager, the fair value of the investment is based on valuations provided by the broker or lead underwriter of the investment (the "broker"). Our CLO equity investments 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. In providing valuations, the CLO equity manager and brokers use observable and unobservable inputs. Of the significant unobservable market inputs used, the default and loss severity rates involve the most judgment and create the most sensitivity. A significant increase or decrease in either of these significant inputs in isolation would result in lower or higher fair value estimates for direct investments in CLO equities and, in general, a change in default rate assumptions will be accompanied by a directionally similar change in loss severity rate assumptions. Collateral spreads and estimated maturity dates are less subjective inputs because they are based on the historical average of actual spreads and the weighted-average life of the current underlying portfolios, respectively. A significant increase or decrease in either of these significant inputs in isolation would result in higher or lower fair value estimates for direct investments in CLO equities. In general, these inputs have no significant interrelationship with each other or with default and loss severity rates. On a quarterly basis, we receive the valuation from the external CLO manager and brokers and then review the underlying cash flows and key assumptions used by them. We review and update the significant unobservable inputs based on information obtained from secondary markets. These inputs are our responsibility and we assess the reasonableness of the inputs (and if necessary, update the inputs) through communicating with industry participants, monitoring of the transactions in which we participate (for example, to evaluate default and loss severity rate trends), and reviewing market conditions, historical results, and emerging trends that may impact future cash flows. If valuations from the external CLO equity manager or brokers are not available, we use an income approach based on certain observable and unobservable inputs to value these investments. An income approach is also used to corroborate the reasonableness of the valuations provided by the external manager and brokers. Where an income approach is followed, the valuation is based on available trade information, such as expected cash flows and market assumptions on default and loss severity rates. Other inputs used in the valuation process include asset spreads, loan prepayment speeds, collateral spreads and estimated maturity dates. • For our investments in 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 values of these investments were measured using the NAV as a practical expedient and therefore have not been categorized within the fair value hierarchy. • For our investments in call options on publicly traded equities, we measure fair value by obtaining the latest option price as of our reporting date. These were classified as Level 2. As at December 31, 2016, the call option had been sold. Derivative Instruments The fair values of our foreign currency exchange contracts, as described in Note 9 - "Derivative Instruments" are classified as Level 2. The fair values are based upon prices in active markets for identical contracts. Changes in Leveling of Financial Instruments 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. During the year ended December 31, 2016 , we transferred $64.1 million of corporate securities, $2.8 million of residential mortgage-backed securities, $23.6 million of commercial mortgage-backed securities and $31.8 million of asset-backed securities from Level 2 to Level 3. These securities were transferred from Level 2 to Level 3 due to insufficient market observable inputs for the valuation of the specific assets. During the year ended December 31, 2016 , we transferred $2.3 million of corporate securities, $0.6 million of residential mortgage-backed securities, $37.8 million of commercial mortgage-backed securities and $129.8 million of asset-backed securities from Level 3 to Level 2. The transfers from Level 3 to Level 2 were based upon us obtaining market observable information regarding the valuations of the specific assets. There were no transfers between Levels 1 and 2. The following table presents a reconciliation of the beginning and ending balances for all investments measured at fair value on a recurring basis using Level 3 inputs during the years ended December 31, 2016 and 2015 : 2016 2015 Fixed Other Investments Equity Securities Total Fixed Other Investments Equity Securities Total Beginning fair value $ 147,144 $ 77,016 $ — $ 224,160 $ 600 $ 42,267 $ 4,850 $ 47,717 Purchases 58,552 6,885 — 65,437 — 106,433 — 106,433 Sales (52,841 ) (12,933 ) — (65,774 ) (600 ) (46,084 ) (5,000 ) (51,684 ) Total realized and unrealized gains (losses) (3,222 ) 5,910 — 2,688 — (25,600 ) 150 (25,450 ) Net transfers into (out of) Level 3 (48,194 ) — — (48,194 ) 147,144 — — 147,144 Ending fair value $ 101,439 $ 76,878 $ — $ 178,317 $ 147,144 $ 77,016 $ — $ 224,160 Net realized and unrealized gains related to Level 3 assets in the table above are included in net realized and unrealized (losses) gains in our consolidated statements of earnings. Disclosure of Fair Values for Financial Instruments Carried at Cost As of December 31, 2016 and 2015 , investments in life settlement contracts were carried at cost of $131.7 million and $133.1 million , respectively, and their fair values were $129.5 million and $130.3 million , respectively. The fair value of investments in life settlement contracts is determined using a discounted cash flow methodology that utilizes unobservable inputs. Due to the individual nature of each investment in life settlement contracts and the illiquidity of the existing market, significant inputs to the fair value include our estimates of premiums necessary to keep the policies in-force, and our assumptions for mortality and discount rates. Our mortality assumptions are based on a combination of medical underwriting information obtained from a third-party underwriter for each referenced life and internal proprietary mortality studies of older aged U.S. insured lives. These assumptions are used to develop an estimate of future net cash flows that, after discounting, are intended to be reflective of the asset's value in the life settlement market. Disclosure of fair value of amounts relating to insurance contracts is not required. 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 December 31, 2016 and 2015 .

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	DERIVATIVE 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. At December 31, 2016 , we had two forward currency contracts in place for notional amounts of AU $63.0 million (approximately $45.5 million ) and CA $50.0 million (approximately $37.2 million ), which we had designated as hedges of the net investments in our Australian and Canadian operations. The following table presents the gross notional amounts, estimated fair values recorded within other assets and liabilities and the amounts of the net gains deferred in the currency translation adjustment account which is a component of accumulated other comprehensive income (loss) ("AOCI"), in shareholders' equity, related to our foreign currency forward exchange rate contracts as at December 31, 2016 . December 31, 2016 Fair Value Amount of Gains Deferred in AOCI (Effective Portion) Gross Notional Amount Assets Liabilities Year Ended December 31, 2016 Foreign exchange forward - AUD $ 45,467 $ 2,753 $ 74 $ 2,568 Foreign exchange forward - CAD 37,175 177 — 1,186 Total qualifying hedges $ 82,642 $ 2,930 $ 74 $ 3,754 We did not have any forward currency contract hedges of our net investments in foreign operations as at December 31, 2015 or during the years ended December 31, 2015 and 2014 . We also borrowed €75.0 million during 2016 that was designated as a non-derivative hedge of our net investment in certain subsidiaries whose functional currency is denominated in Euros as described in Note 15 - "Loans Payable". 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 which are not designated as hedging investments. There were no such contracts utilized during the years ended December 31, 2016 , 2015 and 2014 . Investments in Call Options on Equities We use equity call option instruments either to obtain exposure to a particular equity instrument or for yield enhancement, in non-qualifying hedging relationships. During the year ended December 31, 2016 we purchased call options on equities at a cost of $5.5 million and sold these for a realized gain of $5.4 million . We did not have any equity derivative instruments during the years ended December 31, 2015 and 2014 .

Reinsurance Balances Recoverabl

Reinsurance Balances Recoverable	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
Reinsurance Balances Recoverable	REINSURANCE BALANCES RECOVERABLE The following table provides the total reinsurance balances recoverable as at December 31, 2016 and, 2015 : 2016 Non-life Run-off Atrium StarStone Life and Annuities Total Recoverable from reinsurers on unpaid: Outstanding losses $ 621,288 $ 6,438 $ 182,478 $ 190 $ 810,394 IBNR 393,550 21,753 178,259 — 593,562 Fair value adjustments (13,885 ) 1,818 (3,506 ) — (15,573 ) Total reinsurance reserves recoverable 1,000,953 30,009 357,231 190 1,388,383 Paid losses recoverable 47,160 (1,081 ) 25,512 769 72,360 $ 1,048,113 $ 28,928 $ 382,743 $ 959 $ 1,460,743 2015 Non-life Run-off Atrium StarStone Life and Annuities Total Recoverable from reinsurers on unpaid: Outstanding losses $ 587,164 $ 6,772 $ 182,076 $ 1,544 $ 777,556 IBNR 465,211 16,581 123,732 — 605,524 Fair value adjustments (17,628 ) 2,499 (6,025 ) — (21,154 ) Total reinsurance reserves recoverable 1,034,747 25,852 299,783 1,544 1,361,926 Paid losses recoverable 72,213 430 16,568 784 89,995 $ 1,106,960 $ 26,282 $ 316,351 $ 2,328 $ 1,451,921 Our insurance and reinsurance run-off subsidiaries, prior to acquisition, used retrocessional agreements to reduce their exposure to the risk of insurance and reinsurance assumed. On an annual basis, both Atrium and StarStone purchase a tailored outwards reinsurance program designed to manage their risk profiles. The majority of Atrium’s and StarStone's third-party reinsurance cover is with highly rated reinsurers or is collateralized by 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 discount rate equivalent to an interest rate for securities with similar duration to the reinsurance recoverables acquired including a spread to reflect credit risk, and are amortized over the estimated recovery period, as adjusted for accelerations in timing of payments as a result of commutation settlements. As of December 31, 2016 and 2015 , we had reinsurance balances recoverable of approximately $1.46 billion and $1.45 billion , respectively. The increase of $8.8 million in reinsurance balances recoverable was primarily a result of the additional coverage provided by KaylaRe Ltd., offset by commutations and cash collections made during the year ended December 31, 2016 in our Non-life Run-off and StarStone segments. Top Ten Reinsurers December 31, 2016 December 31, 2015 Non-life Atrium StarStone Life and Total % of Non-life Atrium StarStone Life and Total % of Top ten reinsurers $ 737,074 $ 23,245 $ 226,283 $ — $ 986,602 67.6 % $ 713,743 $ 21,394 $ 155,171 $ — $ 890,308 61.4 % Other reinsurers > $1 million 301,856 4,827 152,341 — 459,024 31.4 % 383,898 4,253 158,417 — 546,568 37.6 % Other reinsurers < $1 million 9,183 856 4,119 959 15,117 1.0 % 9,319 635 2,763 2,328 15,045 1.0 % Total $ 1,048,113 $ 28,928 $ 382,743 $ 959 $ 1,460,743 100.0 % $ 1,106,960 $ 26,282 $ 316,351 $ 2,328 $ 1,451,921 100.0 % The top ten external reinsurers, as at December 31, 2016 and 2015 , were all rated A- or better, with the exception of four non-rated reinsurers from which $512.2 million was recoverable ( December 31, 2015 : $337.6 million recoverable from three non-rated reinsurers). For the four non-rated reinsurers, we hold security in the form of pledged assets in trust, letters of credit issued to us, or funds withheld in the full amount of the recoverable. As at December 31, 2016 , reinsurance balances recoverable of $241.7 million and $154.7 million , respectively, related to KaylaRe Ltd. and Lloyd’s syndicates, both of which represent 10% or more of total reinsurance balances recoverable. Lloyd’s is rated ‘A+’ by Standard & Poor’s and ‘A’ by A.M. Best. KaylaRe Ltd. is not rated but is an affiliated company partly owned by Enstar, as described in Note 21 - "Related Party Transactions", and security is provided in the form of funds withheld. As at December 31, 2015 , reinsurance balances recoverable with a carrying value of $165.6 million related to Lloyd's syndicates and represented 10% or more of total reinsurance balances recoverable. Provisions for Uncollectible Reinsurance Recoverables We remain liable to the extent that retrocessionaires do not meet their obligations under these agreements, and therefore, we evaluate and monitor concentration of credit risk among our reinsurers. Provisions are made for amounts considered potentially uncollectible. The following table shows our reinsurance balances recoverable by rating of reinsurer and our provisions for uncollectible reinsurance balances recoverable ("provisions for bad debt") as at December 31, 2016 and 2015 . The provisions for bad debt all relate to the Non-life Run-off segment. 2016 2015 Gross Provisions for Bad Debt Net Provisions as a Gross Provisions for Bad Debt Net Provisions as a Reinsurers rated A- or above $ 892,776 $ 35,184 $ 857,592 3.9 % $ 1,029,844 $ 46,969 $ 982,875 4.6 % Reinsurers rated below A-, secured 544,894 — 544,894 — % 388,399 — 388,399 — % Reinsurers rated below A-, unsecured 197,589 139,332 58,257 70.5 % 244,005 163,358 80,647 66.9 % Total $ 1,635,259 $ 174,516 $ 1,460,743 10.7 % $ 1,662,248 $ 210,327 $ 1,451,921 12.7 % PREMIUMS WRITTEN AND EARNED The following tables provide a summary of net premiums written and earned in our Non-life Run-off, Atrium, StarStone and Life and Annuities segments for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Premiums Written Premiums Earned Premiums Written Premiums Earned Premiums Written Premiums Earned Non-life Run-off Gross $ 17,316 $ 25,989 $ 38,704 $ 116,494 $ 12,818 $ 45,684 Ceded (8,114 ) (9,234 ) (16,110 ) (72,125 ) (2,546 ) (14,516 ) Net $ 9,202 $ 16,755 $ 22,594 $ 44,369 $ 10,272 $ 31,168 Atrium Gross $ 143,170 $ 140,438 $ 149,082 $ 149,310 $ 154,248 $ 153,816 Ceded (2,733 ) (16,022 ) (14,502 ) (14,635 ) (17,973 ) (17,871 ) Net $ 140,437 $ 124,416 $ 134,580 $ 134,675 $ 136,275 $ 135,945 StarStone Gross $ 854,699 $ 830,186 $ 824,714 $ 769,875 $ 512,219 $ 528,135 Ceded (206,663 ) (153,578 ) (196,287 ) (196,729 ) (113,045 ) (154,502 ) Net $ 648,036 $ 676,608 $ 628,427 $ 573,146 $ 399,174 $ 373,633 Life and Annuities Life $ 6,261 $ 5,735 $ 1,553 $ 1,554 $ 2,235 $ 2,245 Total $ 803,936 $ 823,514 $ 787,154 $ 753,744 $ 547,956 $ 542,991

Losses and Loss Adjustment Expe

Losses and Loss Adjustment Expenses	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
Losses and Loss Adjustment Expenses	LOSSES AND LOSS ADJUSTMENT EXPENSES The liability for losses and LAE, also referred to as loss reserves, represents our gross estimates before reinsurance for unpaid reported losses and losses that have been incurred but not reported ("IBNR") for our Non-life Run-off, Atrium and StarStone segments. 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. The following table summarizes the liability for losses and LAE by segment as at December 31, 2016 and 2015 : 2016 2015 Non-life Run-off Atrium StarStone Total Non-life Atrium StarStone Total Outstanding losses $ 2,697,737 $ 67,379 $ 502,115 $ 3,267,231 $ 2,757,774 $ 68,913 $ 457,175 $ 3,283,862 IBNR 2,153,994 132,240 558,130 2,844,364 1,991,009 115,613 477,990 2,584,612 Fair value adjustments (135,368 ) 12,503 (863 ) (123,728 ) (163,329 ) 16,491 (1,487 ) (148,325 ) Total $ 4,716,363 $ 212,122 $ 1,059,382 $ 5,987,867 $ 4,585,454 $ 201,017 $ 933,678 $ 5,720,149 The table below provides a consolidated reconciliation of the beginning and ending liability for losses and LAE for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Balance as at January 1 $ 5,720,149 $ 4,509,421 $ 4,219,905 Less: reinsurance reserves recoverable 1,360,382 1,154,196 1,146,588 Less: deferred charge on retroactive reinsurance 255,911 — — Net balance as at January 1 4,103,856 3,355,225 3,073,317 Net incurred losses and LAE: Current period 493,016 476,364 327,817 Prior periods (318,917 ) (372,031 ) (318,671 ) Total net incurred losses and LAE 174,099 104,333 9,146 Net paid losses: Current period (79,579 ) (99,933 ) (166,796 ) Prior periods (753,478 ) (681,956 ) (420,715 ) Total net paid losses (833,057 ) (781,889 ) (587,511 ) Effect of exchange rate movement (46,903 ) (65,069 ) (69,804 ) Acquired on purchase of subsidiaries 10,019 878,815 901,447 Assumed business 1,340,444 612,441 28,630 Ceded business (243,335 ) — — Net balance as at December 31 4,505,123 4,103,856 3,355,225 Plus: reinsurance reserves recoverable 1,388,193 1,360,382 1,154,196 Plus: deferred charge on retroactive reinsurance 94,551 $ 255,911 — Balance as at December 31 $ 5,987,867 $ 5,720,149 $ 4,509,421 The tables below provide the components of net incurred losses and LAE by segment for the years ended December 31, 2016 , 2015 and 2014 : Year Ended December 31, 2016 Non-life Atrium StarStone Total Net losses paid $ 533,806 $ 47,998 $ 251,253 $ 833,057 Net change in case and LAE reserves (608,785 ) (148 ) 73,049 (535,884 ) Net change in IBNR reserves (347,384 ) 13,700 75,643 (258,041 ) Amortization of deferred charges 168,827 — — 168,827 Increase (reduction) in estimates of net ultimate losses (253,536 ) 61,550 399,945 207,959 Reduction in provisions for bad debt (13,822 ) — — (13,822 ) Increase (reduction) in provisions for unallocated LAE (43,955 ) 145 3,543 (40,267 ) Amortization of fair value adjustments 25,432 (3,308 ) (1,895 ) 20,229 Net incurred losses and LAE $ (285,881 ) $ 58,387 $ 401,593 $ 174,099 Year Ended December 31, 2015 Non-life Run-off Atrium StarStone Total Net losses paid $ 517,295 $ 52,035 $ 212,559 $ 781,889 Net change in case and LAE reserves (355,335 ) (709 ) 77,219 (278,825 ) Net change in IBNR reserves (364,774 ) 2,844 37,904 (324,026 ) Amortization of deferred charges 15,265 — — 15,265 Increase (reduction) in estimates of net ultimate losses (187,549 ) 54,170 327,682 194,303 Reduction in provisions for bad debt (25,271 ) — — (25,271 ) Increase (reduction) in provisions for unallocated LAE (62,653 ) (83 ) 3,537 (59,199 ) Amortization of fair value adjustments 4,643 (6,608 ) (3,535 ) (5,500 ) Net incurred losses and LAE $ (270,830 ) $ 47,479 $ 327,684 $ 104,333 Year Ended December 31, 2014 Non-life Atrium StarStone Total Net losses paid $ 400,096 $ 57,611 $ 129,804 $ 587,511 Net change in case and LAE reserves (310,414 ) (2,684 ) 37,604 (275,494 ) Net change in IBNR reserves (301,784 ) 11,557 58,870 (231,357 ) Amortization of deferred charges — — — — Increase (reduction) in estimates of net ultimate losses (212,102 ) 66,484 226,278 80,660 Increase in provisions for bad debt (7,700 ) — — (7,700 ) Reduction in provisions for unallocated LAE (48,891 ) 9 (5,088 ) (53,970 ) Amortization of fair value adjustments 3,982 (11,065 ) (2,761 ) (9,844 ) Net incurred losses and LAE $ (264,711 ) $ 55,428 $ 218,429 $ 9,146 Methodology for Establishing Reserves The liability for losses and LAE includes an amount determined from reported claims and an amount based on historical loss experience and industry statistics for IBNR using a variety of actuarial methods. Our loss reserves cover multiple lines of business, which include workers' compensation, general casualty, asbestos and environmental, marine, aviation and transit, construction defects and other non-life lines of business. Our management, through our loss reserving committees, considers the reasonableness of loss reserves recommended by our actuaries, including actual loss development during the year. Case reserves are recognized for known claims (including the cost of related litigation) when sufficient information has been developed to indicate the involvement of a specific insurance policy. We use considerable judgment in estimating losses for reported claims on an individual claim basis based upon our knowledge of the circumstances surrounding the claim, the severity of the injury or damage, the jurisdiction of the occurrence, the potential for ultimate exposure, the type of loss, and our experience with the line of business and policy provisions relating to the particular type of claim. The reserves for unpaid reported losses and LAE are established by management based on reports from brokers, ceding companies and insureds and represent the estimated ultimate cost of events or conditions that have been reported to, or specifically identified, by us. We also consider facts currently known and the current state of the law and coverage litigation. IBNR reserves are established by management based on actuarially determined estimates of ultimate losses and loss expenses. We use generally accepted actuarial methodologies to estimate ultimate losses and LAE and those estimates are reviewed by our management. In addition, the routine settlement of claims, at either below or above the carried advised loss reserve, updates historical loss development information to which actuarial methodologies are applied often, resulting in revised estimates of ultimate liabilities. On an annual basis, independent actuarial firms are retained by management to provide their estimates of ultimate losses and to review the estimates developed by our actuaries. Within the annual loss reserve studies produced by either our actuaries or independent actuaries, exposures for each subsidiary are separated into homogeneous reserving categories for the purpose of estimating IBNR. Each reserving category contains either direct insurance or assumed reinsurance reserves and groups relatively similar types of risks and exposures (for example, asbestos, environmental, casualty, property) and lines of business written (for example, marine, aviation, non-marine). Based on the exposure characteristics and the nature of available data for each individual reserving category, a number of methodologies are applied. Recorded reserves for each category are selected from the actuarial indications produced by the various methodologies after consideration of exposure characteristics, data limitations and strengths and weaknesses of each method applied. This approach to estimating IBNR has been consistently adopted in the annual loss reserve studies for each period presented. The estimation of unpaid claim liabilities at any given point in time is subject to a high degree of uncertainty for a number of reasons. A significant amount of time can lapse between the assumption of risk, the occurrence of a loss event, the reporting of the event to an insurance or reinsurance company and the ultimate payment of the claim on the loss event. Our actuarial methodologies include industry benchmarking which, under certain methodologies, compares the trend of our loss development to that of the industry. To the extent that the trend of our loss development compared to the industry changes in any period, it is likely to have an impact on the estimate of ultimate liabilities. Unpaid claim liabilities for property and casualty exposures in general are impacted by changes in the legal environment, jury awards, medical cost trends and general inflation. Certain estimates for unpaid claim liabilities involve considerable uncertainty due to significant coverage litigation, and it can be unclear whether past claim experience will be representative of future claim experience. Ultimate values for such claims cannot be estimated using reserving techniques that extrapolate losses to an ultimate basis using loss development factors, and the uncertainties surrounding the estimation of unpaid claim liabilities are not likely to be resolved in the near future. In addition, reserves are established to cover loss development related to both known and unasserted claims. Consequently, our subsequent estimates of ultimate losses and LAE, and our liability for losses and LAE, may differ materially from the amounts recorded in the consolidated financial statements. These estimates are reviewed regularly and, as experience develops and new information becomes known, the reserves are adjusted as necessary. Such adjustments, if any, will be recorded in earnings in the period in which they become known. Prior period development arises from changes to loss estimates recognized in the current year that relate to loss reserves established in previous calendar years. Non-Life Run-off Segment The table below provides a reconciliation of the beginning and ending reserves for losses and LAE for the years ended December 31, 2016 , 2015 and 2014 for the Non-life Run-off segment: 2016 2015 2014 Balance as at January 1 $ 4,585,454 $ 3,435,010 $ 4,004,513 Less: reinsurance reserves recoverable 1,034,747 800,709 1,121,533 Less: deferred charge on retroactive reinsurance 255,911 — — Net balance as at January 1 3,294,796 2,634,301 2,882,980 Net incurred losses and LAE: Current period 5,829 39,924 24,235 Prior periods (291,710 ) (310,754 ) (288,946 ) Total net incurred losses and LAE (285,881 ) (270,830 ) (264,711 ) Net paid losses: Current period (3,869 ) (16,049 ) (87,681 ) Prior periods (529,937 ) (501,246 ) (312,415 ) Total net paid losses (533,806 ) (517,295 ) (400,096 ) Effect of exchange rate movement (27,478 ) (42,636 ) (49,267 ) Acquired on purchase of subsidiaries 10,019 878,815 436,765 Assumed business 1,340,444 612,441 28,630 Ceded business (177,235 ) — — Net balance as at December 31 3,620,859 3,294,796 2,634,301 Plus: reinsurance reserves recoverable 1,000,953 1,034,747 800,709 Plus: deferred charge on retroactive reinsurance 94,551 255,911 — Balance as at December 31 $ 4,716,363 $ 4,585,454 $ 3,435,010 Net incurred losses and LAE in the Non-life Run-off segment for the years ended December 31, 2016 , 2015 and 2014 were as follows: 2016 2015 2014 Prior Period Current Period Total Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 529,937 $ 3,869 $ 533,806 $ 501,246 $ 16,049 $ 517,295 $ 312,415 $ 87,681 $ 400,096 Net change in case and LAE reserves (608,168 ) (617 ) (608,785 ) (366,262 ) 10,927 (355,335 ) (285,814 ) (24,600 ) (310,414 ) Net change in IBNR reserves (349,726 ) 2,342 (347,384 ) (377,722 ) 12,948 (364,774 ) (262,384 ) (39,400 ) (301,784 ) Amortization of deferred charges 168,827 — 168,827 15,265 — 15,265 — — — Increase (reduction) in estimates of net ultimate losses (259,130 ) 5,594 (253,536 ) (227,473 ) 39,924 (187,549 ) (235,783 ) 23,681 (212,102 ) Increase (reduction) in provisions for bad debt (13,822 ) — (13,822 ) (25,271 ) — (25,271 ) (7,700 ) — (7,700 ) Increase (reduction) in provisions for unallocated LAE (44,190 ) 235 (43,955 ) (62,653 ) — (62,653 ) (49,445 ) 554 (48,891 ) Amortization of fair value adjustments 25,432 — 25,432 4,643 — 4,643 3,982 — 3,982 Net incurred losses and LAE $ (291,710 ) $ 5,829 $ (285,881 ) $ (310,754 ) $ 39,924 $ (270,830 ) $ (288,946 ) $ 24,235 $ (264,711 ) Net change in case and LAE reserves comprises the movement during the year 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. Year Ended December 31, 2016 The net reduction in incurred losses and LAE for the year ended December 31, 2016 of $285.9 million included net incurred losses a nd LAE of $5.8 million related to current period net earned premium of $7.1 million (primarily for the portion of the run-off business acquired with Sussex). Excluding current period net incurred losses and LAE of $5.8 million , net incurred losses and LAE liabilities relating to prior periods were reduced by $291.7 million , which was attributable to a reduction in estimates of net ultimate losses of $259.1 million , a reduction in provisions for bad debt of $13.8 million and a reduction in provisions for unallocated LAE of $44.2 million , relating to 2016 run-off activity, partially offset by amortization of fair value adjustments over the estimated payout period relating to companies acquired amounting to $25.4 million . The reduction in estimates of net ultimate losses relating to prior periods of $259.1 million comprised reductions in IBNR reserves of $349.7 million partially offset by net incurred loss development of $90.6 million , which includes amortization of deferred charges of $168.8 million . The decrease in the estimate of net IBNR reserves of $349.7 million (compared to $377.7 million during the year ended December 31, 2015 ), was comprised of an increase of $39.4 million relating to asbestos liabilities (compared to a decrease of $32.0 million in 2015 ), an increase of $35.5 million relating to environmental liabilities (compared to a decrease $1.6 million in 2015 ), a decrease of $0.8 million relating to general casualty liabilities (compared to $3.0 million in 2015 ), a decrease of $333.2 million relating to workers' compensation liabilities (compared to $243.4 million in 2015 ) and a decrease of $90.6 million relating to all other remaining liabilities (compared to $97.7 million in 2015 ). The reduction in net IBNR reserves of $349.7 million relating to prior periods was a result of the application, on a basis consistent with the assumptions applied in the prior period, of our actuarial methodologies to revised historical loss development data, following 56 commutations and policy buy-backs, to estimate loss reserves required to cover liabilities for unpaid losses and LAE relating to non-commuted exposures. The prior period estimate of net IBNR reserves was reduced as a result of the combined impact on all classes of business of loss development activity during 2016 , including commutations and the favorable trend of loss development related to non-commuted policies compared to prior forecasts. The net incurred loss development resulting from settlement of net advised case and LAE reserves of $608.2 million for net paid losses of $529.9 million related to the settlement of non-commuted losses in the year and 56 commutations and policy buy-backs of assumed and ceded exposures. Net advised case and LAE reserves settled by way of commutation and policy buyback during the year ended December 31, 2016 amounted to $14.7 million (comprising $39.1 million of assumed case reserves and LAE reserves, partially offset by $24.4 million of ceded incurred reinsurance recoverable case reserves). The reduction in provisions for bad debt of $13.8 million was a result of the favorable resolution of contractual disputes with reinsurers, the reduction in bad debt provisions for insolvent reinsurers as a result of dividends received and the reduction of specific provisions held for potential disputes with reinsurers. Year Ended December 31, 2015 The net reduction in incurred losses and LAE for the year ended December 31, 2015 of $270.8 million included current period net incurred losses and LAE of $39.9 million related to current period net earned premium of $43.3 million (primarily for the portion of the run-off business acquired with StarStone). Excluding current period net losses and LAE of $39.9 million , net incurred losses and LAE liabilities relating to prior periods were reduced by $310.8 million , which was attributable to a reduction in estimates of net ultimate losses of $227.5 million , reduction in provisions for bad debts of $25.3 million and a reduction in provision for unallocated LAE of $62.7 million , relating to 2015 run-off activity, partially offset by amortization of fair value adjustments over the estimated payout period relating to companies acquired amounting to $4.6 million . The reduction in estimates of net ultimate losses relating to prior periods of $227.5 million comprised reductions in IBNR reserves of $377.7 million partially offset by net incurred loss development of $150.2 million , which includes amortization of deferred charges of $15.3 million . The decrease in the estimate of net IBNR reserves of $377.7 million (compared to $262.4 million during the year ended December 31, 2014 ) was comprised of $32.0 million relating to asbestos liabilities (compared to $59.4 million in 2014 ), $1.6 million relating to environmental liabilities (compared to $6.2 million in 2014 ), $3.0 million relating to general casualty liabilities (compared to $62.5 million in 2014 ), $243.4 million relating to workers' compensation liabilities (compared to $63.6 million in 2014 ) and $97.7 million relating to all other remaining liabilities (compared to $70.7 million in 2014 ). The reduction in net IBNR reserves of $377.7 million relating to prior periods was a result of the application, on a basis consistent with the assumptions applied in the prior period, o f our actuarial methodologies to revised historical loss development data, following 79 commutations and policy buy-backs, to estimate loss reserves required to cover liabilities for unpaid losses and LAE relating to non-commuted exposures. The prior period estimate of net IBNR reserves was reduced as a result of the combined impact on all classes of business of loss development activity during 2015 , including commutations and the favorable trend of loss development related to non-commuted policies compared to prior forecasts. The net incurred loss development resulting from settlement of net advised case and LAE reserves of $366.3 million for net paid losses of $501.2 million related to the settlement of non-commuted losses in the year and 79 commutations and policy buy-backs of assumed and ceded exposures (including the commutation of two of our top ten assumed exposures and one of our top ten ceded recoverables as at January 1, 2014). Net advised case and LAE reserves settled by way of commutation and policy buy-back during the year ended December 31, 2015 amounted to $56.6 million (comprising $140.3 million of assumed case reserves and LAE reserves partially offset by $83.7 million of ceded incurred reinsurance recoverable case reserves). The reduction in provisions for bad debt of $25.3 million was a result of the collection of certain reinsurance recoverables against which bad debt provisions had been provided in earlier periods, and the reduction in bad debt provisions for insolvent reinsurers as a result of dividends received, partially offset by additional provisions for contractual disputes with reinsurers. Year Ended December 31, 2014 The net reduction in incurred losses and LAE for the year ended December 31, 2014 of $ 264.7 million included current period incurred losses of $24.2 million related to SeaBright. Excluding SeaBright's current period net incurred losses and LAE of $24.2 million net incurred losses and LAE relating to prior periods were reduced by $288.9 million which was attributable to a reduction in estimates of net ultimate losses of $235.8 million and a reduction in provisions for unallocated LAE of $49.4 million , relating to 2014 run-off activity, partially offset by an increase in provisions for bad debt of $7.7 million and the amortization of fair value adjustments over the estimated payout period relating to companies acquired amounting to $4.0 million . The reduction in estimates of net ultimate losses relating to prior periods of $235.8 million comprised reductions in net IBNR reserves of $262.4 million partially offset by net incurred loss development of $26.6 million . The decrease in the estimate of net IBNR reserves of $262.4 million (compared to $265.2 million during the year ended December 31, 2013 ) was comprised of $59.4 million relating to asbestos liabilities (compared to $69.8 million in 2013 ), $6.2 million relating to environmental liabilities (compared to $4.9 million in 2013 ), $62.5 million relating to general casualty liabilities (compared to $42.6 million in 2013 ), $63.6 million relating to workers' compensation liabilities (compared to $42.1 million in 2013 ) and $70.7 million relating to all other remaining liabilities (compared to $105.8 million in 2013 ). The reduction in net IBNR reserves of $262.4 million relating to prior periods was a result of the application, on a basis consistent with the assumptions applied in the prior period, of our actuarial methodologies to revised historical loss development data, following 98 commutations and policy buy-backs, to estimate loss reserves required to cover liabilities for unpaid losses and LAE relating to non-commuted exposures. The prior period estimate of net IBNR reserves was reduced as a result of the combined impact on all classes of business of loss development activity during 2014 , including commutations and the favorable trend of loss development related to non-commuted policies compared to prior forecasts. The net incurred loss development resulting from settlement of net advised case and LAE reserves of $285.8 million for net paid losses of $312.4 million related to the settlement of non-commuted losses in the year and 98 commutations and policy buy-backs of assumed and ceded exposures (including the commutation of one of our top ten assumed exposures and one of our top ten ceded recoverables as at January 1, 2013). Net advised case and LAE reserves settled by way of commutation and policy buy-back during the year ended December 31, 2014 amounted to $29.1 million (comprising $99.5 million of assumed case reserves and LAE reserves partially offset by $70.4 million of ceded incurred reinsurance recoverable case reserves). The increase in provisions for bad debt of $7.7 million was a result of additional provisions being allowed for contractual disputes with reinsurers, offset by cash collections and commutations on certain reinsurance recoverables against which bad debt provisions had been provided in earlier periods. Asbestos and Environmental In establishing the reserves for losses and LAE related to asbestos and environmental claims, management considers facts currently known and the current state of the law and coverage litigation. Liabilities are recognized for known claims (including the cost of related litigation) when sufficient information has been developed to indicate the involvement of a specific insurance policy, and management can reasonably estimate its liability. In addition, reserves have been established to cover additional exposures on both known and unreported claims. Estimates of the reserves are reviewed and updated continually. Developed case law and claim histories are still evolving for such claims, especially because significant uncertainty exists about the outcome of coverage litigation and whether past claim experience will be representative of future claim experience. In view of the changes in the legal and tort environment that affect the development of such claims, the uncertainties inherent in valuing asbestos and environmental claims are not likely to be resolved in the near future. Ultimate values for such claims cannot be estimated using traditional reserving techniques and there are significant uncertainties in estimating the amount of our potential losses for these claims. There can be no assurance that the reserves established by us will be adequate or will not be adversely affected by the development of other latent exposures. The liability for unpaid losses and LAE as of December 31, 2016 and 2015 included $921.2 million and $356.6 million , respectively, which represented an estimate of the net ultimate liability for asbestos and environmental claims. The gross liability for such claims as at December 31, 2016 and 2015 was $951.1 million and $390.8 million , respectively. Disclosures of Incurred and Paid Loss Development, IBNR, Claims Counts and Payout Percentages The following table provides a breakdown of the gross and net losses and LAE reserves by major category as at December 31, 2016: 2016 2016 Gross Net OLR IBNR Total OLR IBNR Total (in thousands of U.S. dollars) Asbestos $ 240,863 $ 548,180 $ 789,043 $ 230,983 $ 533,361 $ 764,344 Environmental 94,432 67,646 162,078 91,362 65,507 156,869 General casualty 427,733 316,227 743,960 301,699 190,053 491,752 Workers' compensation/personal accident 1,360,743 693,585 2,054,328 915,704 457,119 1,372,823 Marine, aviation and transit 45,240 34,873 80,113 39,816 34,678 74,494 Construction defect 39,622 120,459 160,081 32,449 88,647 121,096 Other 407,490 100,934 508,424 325,734 95,411 421,145 Total $ 2,616,123 $ 1,881,904 $ 4,498,027 $ 1,937,747 $ 1,464,776 $ 3,402,523 ULAE 218,336 218,336 Total $ 4,716,363 $ 3,620,859 As noted in the table above, the significant categories within this segment include asbestos, general casualty and workers’ compensation, which collectively comprised approximately 80% and 77% of the total gross and net reserves as at December 31, 2016. Separate claims development tables have been provided for the workers’ compensation and general casualty categories as set forth below. The asbestos category is wholly comprised of losses with accident years before 2007 and therefore accident year claims development tables are excluded from these disclosures. The exposures included in the other category includes losses with several different development patterns that are not individually sufficiently significant to be disclosed in separate claims development tables. Our non-life run-off segment is unique within the insurance industry. Legacy reserves are continuously being acquired into this segment through company acquisition or through loss portfolio transfer reinsurance. The loss development tables in this segment include actual loss development as well as the effects of assimilating newly acquired reserves. Accordingly, it would not be appropriate to extrapolate redundancies or deficiencies into the future or to infer actual historical accident year development information from the tables provided below. Acquired reserves for company acquisitions are shown on a full retrospective basis. Assumed reserves for loss portfolio reinsurance transactions are shown as follows: (i) unpaid reported claims are shown on a full retrospective basis and (ii) assumed IBNR is shown on a prospective basis as historical IBNR is generally not available to us in these transactions. For further information, we have disclosed additional development tables for reported claims, for IBNR, and for IBNR acquired in loss portfolio reinsurance transactions. General Casualty The following tables set forth information about incurred and paid loss development information related to our general casualty category within the Non-life Run-off segment as at December 31, 2016. The information related to incurred and paid loss development for the years ended December 31, 2007 through 2015 is presented as supplementary information and is unaudited. Unpaid Reported Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) 2007 $ 22,745 $ 26,555 $ 13,847 $ 10,053 $ 15,084 $ 8,757 $ 7,411 $ 6,302 $ 1,929 $ 2,679 2008 43,164 55,854 36,785 29,183 21,275 16,296 11,239 9,138 7,890 2009 19,205 37,028 45,685 34,708 22,834 15,044 14,562 11,333 2010 41,785 92,211 81,789 59,566 42,088 35,806 23,460 2011 19,805 48,609 33,465 32,499 25,227 19,945 2012 44,029 56,594 53,386 37,651 34,804 2013 20,677 23,432 22,681 16,995 2014 10,489 12,537 10,022 2015 3,294 4,356 2016 — 248 Total $ 131,732 IBNR Losses and Loss Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) 2007 $ 8,983 $ 8,409 $ 6,108 $ 6,339 $ 7,485 $ 2,986 $ 3,996 $ 3,356 $ 1,049 $ 1,579 2008 16,731 4,956 15,134 12,253 5,605 7,528 6,491 8,450 4,682 2009 14,131 16,784 15,393 8,240 12,272 9,170 5,363 5,247 2010 22,364 25,904 16,032 28,064 19,770 13,513 18,026 2011 33,180 23,948 34,767 25,659 18,042 20,683 2012 61,807 64,756 45,872 19,383 21,224 2013 70,755 58,446 17,200 16,534 2014 32,309 12,839 9,894 2015 7,697 7,573 2016 2,226 Total $ 107,668 The table below provides a summary of IBNR acquired in assumed loss portfolio transfer reinsurance transactions which is reflected on a prospective basis in the table above from the year in which the transaction occurred: For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) Take-On IBNR for Assumed Business $ — $ 10,740 $ — $ 3,633 $ — $ 25,703 $ — $ 5,263 $ 3,685 $ 36,501 Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 50,012 $ 69,095 $ 77,504 $ 81,587 $ 92,460 $ 86,583 $ 89,022 $ 87,929 $ 86,364 $ 88,081 2008 78,187 114,684 137,678 145,526 147,317 152,589 155,177 158,178 155,909 2009 47,683 95,064 128,373 146,500 164,233 168,363 173,304 173,855 2010 82,340 169,525 200,723 229,345 235,009 260,599 270,864 2011 73,694 134,667 166,450 177,382 186,384 191,245 2012 147,850 225,566 257,655 255,667 280,266 2013 117,545 135,171 113,574 122,148 2014 48,808 39,072 42,370 2015 12,949 16,292 2016 2,690 Total $ 1,343,720 Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For The Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 18,284 $ 34,131 $ 57,548 $ 65,195 $ 69,892 $ 74,840 $ 77,614 $ 78,271 $ 83,386 $ 83,823 2008 18,292 53,874 85,759 104,090 120,437 128,766 137,448 140,589 143,337 2009 14,347 41,253 67,294 103,552 129,127 144,148 153,379 157,275 2010 18,191 51,410 102,903 141,715 173,150 211,280 229,377 2011 20,709 62,110 98,218 119,224 143,116 150,616 2012 42,014 104,216 158,397 198,634 224,238 2013 26,112 53,293 73,693 88,618 2014 6,010 13,696 22,454 2015 1,958 4,364 2016 216 Total $ 1,104,318 All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance 266,163 Total outstanding liabilities for unpaid losses and LAE, net of reinsurance $ 505,565 The reconciliation of incurred and paid loss development to the liability for unpaid losses and LAE as presented in the tables above for the year ended December 31, 2016 is set forth below: December 31, 2016 Liabilities for unpaid losses and allocated LAE, net of re

Policy Benefits for Life Contra

Policy Benefits for Life Contracts	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
Policy Benefits for Life Contracts	LOSSES AND LOSS ADJUSTMENT EXPENSES The liability for losses and LAE, also referred to as loss reserves, represents our gross estimates before reinsurance for unpaid reported losses and losses that have been incurred but not reported ("IBNR") for our Non-life Run-off, Atrium and StarStone segments. 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. The following table summarizes the liability for losses and LAE by segment as at December 31, 2016 and 2015 : 2016 2015 Non-life Run-off Atrium StarStone Total Non-life Atrium StarStone Total Outstanding losses $ 2,697,737 $ 67,379 $ 502,115 $ 3,267,231 $ 2,757,774 $ 68,913 $ 457,175 $ 3,283,862 IBNR 2,153,994 132,240 558,130 2,844,364 1,991,009 115,613 477,990 2,584,612 Fair value adjustments (135,368 ) 12,503 (863 ) (123,728 ) (163,329 ) 16,491 (1,487 ) (148,325 ) Total $ 4,716,363 $ 212,122 $ 1,059,382 $ 5,987,867 $ 4,585,454 $ 201,017 $ 933,678 $ 5,720,149 The table below provides a consolidated reconciliation of the beginning and ending liability for losses and LAE for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Balance as at January 1 $ 5,720,149 $ 4,509,421 $ 4,219,905 Less: reinsurance reserves recoverable 1,360,382 1,154,196 1,146,588 Less: deferred charge on retroactive reinsurance 255,911 — — Net balance as at January 1 4,103,856 3,355,225 3,073,317 Net incurred losses and LAE: Current period 493,016 476,364 327,817 Prior periods (318,917 ) (372,031 ) (318,671 ) Total net incurred losses and LAE 174,099 104,333 9,146 Net paid losses: Current period (79,579 ) (99,933 ) (166,796 ) Prior periods (753,478 ) (681,956 ) (420,715 ) Total net paid losses (833,057 ) (781,889 ) (587,511 ) Effect of exchange rate movement (46,903 ) (65,069 ) (69,804 ) Acquired on purchase of subsidiaries 10,019 878,815 901,447 Assumed business 1,340,444 612,441 28,630 Ceded business (243,335 ) — — Net balance as at December 31 4,505,123 4,103,856 3,355,225 Plus: reinsurance reserves recoverable 1,388,193 1,360,382 1,154,196 Plus: deferred charge on retroactive reinsurance 94,551 $ 255,911 — Balance as at December 31 $ 5,987,867 $ 5,720,149 $ 4,509,421 The tables below provide the components of net incurred losses and LAE by segment for the years ended December 31, 2016 , 2015 and 2014 : Year Ended December 31, 2016 Non-life Atrium StarStone Total Net losses paid $ 533,806 $ 47,998 $ 251,253 $ 833,057 Net change in case and LAE reserves (608,785 ) (148 ) 73,049 (535,884 ) Net change in IBNR reserves (347,384 ) 13,700 75,643 (258,041 ) Amortization of deferred charges 168,827 — — 168,827 Increase (reduction) in estimates of net ultimate losses (253,536 ) 61,550 399,945 207,959 Reduction in provisions for bad debt (13,822 ) — — (13,822 ) Increase (reduction) in provisions for unallocated LAE (43,955 ) 145 3,543 (40,267 ) Amortization of fair value adjustments 25,432 (3,308 ) (1,895 ) 20,229 Net incurred losses and LAE $ (285,881 ) $ 58,387 $ 401,593 $ 174,099 Year Ended December 31, 2015 Non-life Run-off Atrium StarStone Total Net losses paid $ 517,295 $ 52,035 $ 212,559 $ 781,889 Net change in case and LAE reserves (355,335 ) (709 ) 77,219 (278,825 ) Net change in IBNR reserves (364,774 ) 2,844 37,904 (324,026 ) Amortization of deferred charges 15,265 — — 15,265 Increase (reduction) in estimates of net ultimate losses (187,549 ) 54,170 327,682 194,303 Reduction in provisions for bad debt (25,271 ) — — (25,271 ) Increase (reduction) in provisions for unallocated LAE (62,653 ) (83 ) 3,537 (59,199 ) Amortization of fair value adjustments 4,643 (6,608 ) (3,535 ) (5,500 ) Net incurred losses and LAE $ (270,830 ) $ 47,479 $ 327,684 $ 104,333 Year Ended December 31, 2014 Non-life Atrium StarStone Total Net losses paid $ 400,096 $ 57,611 $ 129,804 $ 587,511 Net change in case and LAE reserves (310,414 ) (2,684 ) 37,604 (275,494 ) Net change in IBNR reserves (301,784 ) 11,557 58,870 (231,357 ) Amortization of deferred charges — — — — Increase (reduction) in estimates of net ultimate losses (212,102 ) 66,484 226,278 80,660 Increase in provisions for bad debt (7,700 ) — — (7,700 ) Reduction in provisions for unallocated LAE (48,891 ) 9 (5,088 ) (53,970 ) Amortization of fair value adjustments 3,982 (11,065 ) (2,761 ) (9,844 ) Net incurred losses and LAE $ (264,711 ) $ 55,428 $ 218,429 $ 9,146 Methodology for Establishing Reserves The liability for losses and LAE includes an amount determined from reported claims and an amount based on historical loss experience and industry statistics for IBNR using a variety of actuarial methods. Our loss reserves cover multiple lines of business, which include workers' compensation, general casualty, asbestos and environmental, marine, aviation and transit, construction defects and other non-life lines of business. Our management, through our loss reserving committees, considers the reasonableness of loss reserves recommended by our actuaries, including actual loss development during the year. Case reserves are recognized for known claims (including the cost of related litigation) when sufficient information has been developed to indicate the involvement of a specific insurance policy. We use considerable judgment in estimating losses for reported claims on an individual claim basis based upon our knowledge of the circumstances surrounding the claim, the severity of the injury or damage, the jurisdiction of the occurrence, the potential for ultimate exposure, the type of loss, and our experience with the line of business and policy provisions relating to the particular type of claim. The reserves for unpaid reported losses and LAE are established by management based on reports from brokers, ceding companies and insureds and represent the estimated ultimate cost of events or conditions that have been reported to, or specifically identified, by us. We also consider facts currently known and the current state of the law and coverage litigation. IBNR reserves are established by management based on actuarially determined estimates of ultimate losses and loss expenses. We use generally accepted actuarial methodologies to estimate ultimate losses and LAE and those estimates are reviewed by our management. In addition, the routine settlement of claims, at either below or above the carried advised loss reserve, updates historical loss development information to which actuarial methodologies are applied often, resulting in revised estimates of ultimate liabilities. On an annual basis, independent actuarial firms are retained by management to provide their estimates of ultimate losses and to review the estimates developed by our actuaries. Within the annual loss reserve studies produced by either our actuaries or independent actuaries, exposures for each subsidiary are separated into homogeneous reserving categories for the purpose of estimating IBNR. Each reserving category contains either direct insurance or assumed reinsurance reserves and groups relatively similar types of risks and exposures (for example, asbestos, environmental, casualty, property) and lines of business written (for example, marine, aviation, non-marine). Based on the exposure characteristics and the nature of available data for each individual reserving category, a number of methodologies are applied. Recorded reserves for each category are selected from the actuarial indications produced by the various methodologies after consideration of exposure characteristics, data limitations and strengths and weaknesses of each method applied. This approach to estimating IBNR has been consistently adopted in the annual loss reserve studies for each period presented. The estimation of unpaid claim liabilities at any given point in time is subject to a high degree of uncertainty for a number of reasons. A significant amount of time can lapse between the assumption of risk, the occurrence of a loss event, the reporting of the event to an insurance or reinsurance company and the ultimate payment of the claim on the loss event. Our actuarial methodologies include industry benchmarking which, under certain methodologies, compares the trend of our loss development to that of the industry. To the extent that the trend of our loss development compared to the industry changes in any period, it is likely to have an impact on the estimate of ultimate liabilities. Unpaid claim liabilities for property and casualty exposures in general are impacted by changes in the legal environment, jury awards, medical cost trends and general inflation. Certain estimates for unpaid claim liabilities involve considerable uncertainty due to significant coverage litigation, and it can be unclear whether past claim experience will be representative of future claim experience. Ultimate values for such claims cannot be estimated using reserving techniques that extrapolate losses to an ultimate basis using loss development factors, and the uncertainties surrounding the estimation of unpaid claim liabilities are not likely to be resolved in the near future. In addition, reserves are established to cover loss development related to both known and unasserted claims. Consequently, our subsequent estimates of ultimate losses and LAE, and our liability for losses and LAE, may differ materially from the amounts recorded in the consolidated financial statements. These estimates are reviewed regularly and, as experience develops and new information becomes known, the reserves are adjusted as necessary. Such adjustments, if any, will be recorded in earnings in the period in which they become known. Prior period development arises from changes to loss estimates recognized in the current year that relate to loss reserves established in previous calendar years. Non-Life Run-off Segment The table below provides a reconciliation of the beginning and ending reserves for losses and LAE for the years ended December 31, 2016 , 2015 and 2014 for the Non-life Run-off segment: 2016 2015 2014 Balance as at January 1 $ 4,585,454 $ 3,435,010 $ 4,004,513 Less: reinsurance reserves recoverable 1,034,747 800,709 1,121,533 Less: deferred charge on retroactive reinsurance 255,911 — — Net balance as at January 1 3,294,796 2,634,301 2,882,980 Net incurred losses and LAE: Current period 5,829 39,924 24,235 Prior periods (291,710 ) (310,754 ) (288,946 ) Total net incurred losses and LAE (285,881 ) (270,830 ) (264,711 ) Net paid losses: Current period (3,869 ) (16,049 ) (87,681 ) Prior periods (529,937 ) (501,246 ) (312,415 ) Total net paid losses (533,806 ) (517,295 ) (400,096 ) Effect of exchange rate movement (27,478 ) (42,636 ) (49,267 ) Acquired on purchase of subsidiaries 10,019 878,815 436,765 Assumed business 1,340,444 612,441 28,630 Ceded business (177,235 ) — — Net balance as at December 31 3,620,859 3,294,796 2,634,301 Plus: reinsurance reserves recoverable 1,000,953 1,034,747 800,709 Plus: deferred charge on retroactive reinsurance 94,551 255,911 — Balance as at December 31 $ 4,716,363 $ 4,585,454 $ 3,435,010 Net incurred losses and LAE in the Non-life Run-off segment for the years ended December 31, 2016 , 2015 and 2014 were as follows: 2016 2015 2014 Prior Period Current Period Total Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 529,937 $ 3,869 $ 533,806 $ 501,246 $ 16,049 $ 517,295 $ 312,415 $ 87,681 $ 400,096 Net change in case and LAE reserves (608,168 ) (617 ) (608,785 ) (366,262 ) 10,927 (355,335 ) (285,814 ) (24,600 ) (310,414 ) Net change in IBNR reserves (349,726 ) 2,342 (347,384 ) (377,722 ) 12,948 (364,774 ) (262,384 ) (39,400 ) (301,784 ) Amortization of deferred charges 168,827 — 168,827 15,265 — 15,265 — — — Increase (reduction) in estimates of net ultimate losses (259,130 ) 5,594 (253,536 ) (227,473 ) 39,924 (187,549 ) (235,783 ) 23,681 (212,102 ) Increase (reduction) in provisions for bad debt (13,822 ) — (13,822 ) (25,271 ) — (25,271 ) (7,700 ) — (7,700 ) Increase (reduction) in provisions for unallocated LAE (44,190 ) 235 (43,955 ) (62,653 ) — (62,653 ) (49,445 ) 554 (48,891 ) Amortization of fair value adjustments 25,432 — 25,432 4,643 — 4,643 3,982 — 3,982 Net incurred losses and LAE $ (291,710 ) $ 5,829 $ (285,881 ) $ (310,754 ) $ 39,924 $ (270,830 ) $ (288,946 ) $ 24,235 $ (264,711 ) Net change in case and LAE reserves comprises the movement during the year 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. Year Ended December 31, 2016 The net reduction in incurred losses and LAE for the year ended December 31, 2016 of $285.9 million included net incurred losses a nd LAE of $5.8 million related to current period net earned premium of $7.1 million (primarily for the portion of the run-off business acquired with Sussex). Excluding current period net incurred losses and LAE of $5.8 million , net incurred losses and LAE liabilities relating to prior periods were reduced by $291.7 million , which was attributable to a reduction in estimates of net ultimate losses of $259.1 million , a reduction in provisions for bad debt of $13.8 million and a reduction in provisions for unallocated LAE of $44.2 million , relating to 2016 run-off activity, partially offset by amortization of fair value adjustments over the estimated payout period relating to companies acquired amounting to $25.4 million . The reduction in estimates of net ultimate losses relating to prior periods of $259.1 million comprised reductions in IBNR reserves of $349.7 million partially offset by net incurred loss development of $90.6 million , which includes amortization of deferred charges of $168.8 million . The decrease in the estimate of net IBNR reserves of $349.7 million (compared to $377.7 million during the year ended December 31, 2015 ), was comprised of an increase of $39.4 million relating to asbestos liabilities (compared to a decrease of $32.0 million in 2015 ), an increase of $35.5 million relating to environmental liabilities (compared to a decrease $1.6 million in 2015 ), a decrease of $0.8 million relating to general casualty liabilities (compared to $3.0 million in 2015 ), a decrease of $333.2 million relating to workers' compensation liabilities (compared to $243.4 million in 2015 ) and a decrease of $90.6 million relating to all other remaining liabilities (compared to $97.7 million in 2015 ). The reduction in net IBNR reserves of $349.7 million relating to prior periods was a result of the application, on a basis consistent with the assumptions applied in the prior period, of our actuarial methodologies to revised historical loss development data, following 56 commutations and policy buy-backs, to estimate loss reserves required to cover liabilities for unpaid losses and LAE relating to non-commuted exposures. The prior period estimate of net IBNR reserves was reduced as a result of the combined impact on all classes of business of loss development activity during 2016 , including commutations and the favorable trend of loss development related to non-commuted policies compared to prior forecasts. The net incurred loss development resulting from settlement of net advised case and LAE reserves of $608.2 million for net paid losses of $529.9 million related to the settlement of non-commuted losses in the year and 56 commutations and policy buy-backs of assumed and ceded exposures. Net advised case and LAE reserves settled by way of commutation and policy buyback during the year ended December 31, 2016 amounted to $14.7 million (comprising $39.1 million of assumed case reserves and LAE reserves, partially offset by $24.4 million of ceded incurred reinsurance recoverable case reserves). The reduction in provisions for bad debt of $13.8 million was a result of the favorable resolution of contractual disputes with reinsurers, the reduction in bad debt provisions for insolvent reinsurers as a result of dividends received and the reduction of specific provisions held for potential disputes with reinsurers. Year Ended December 31, 2015 The net reduction in incurred losses and LAE for the year ended December 31, 2015 of $270.8 million included current period net incurred losses and LAE of $39.9 million related to current period net earned premium of $43.3 million (primarily for the portion of the run-off business acquired with StarStone). Excluding current period net losses and LAE of $39.9 million , net incurred losses and LAE liabilities relating to prior periods were reduced by $310.8 million , which was attributable to a reduction in estimates of net ultimate losses of $227.5 million , reduction in provisions for bad debts of $25.3 million and a reduction in provision for unallocated LAE of $62.7 million , relating to 2015 run-off activity, partially offset by amortization of fair value adjustments over the estimated payout period relating to companies acquired amounting to $4.6 million . The reduction in estimates of net ultimate losses relating to prior periods of $227.5 million comprised reductions in IBNR reserves of $377.7 million partially offset by net incurred loss development of $150.2 million , which includes amortization of deferred charges of $15.3 million . The decrease in the estimate of net IBNR reserves of $377.7 million (compared to $262.4 million during the year ended December 31, 2014 ) was comprised of $32.0 million relating to asbestos liabilities (compared to $59.4 million in 2014 ), $1.6 million relating to environmental liabilities (compared to $6.2 million in 2014 ), $3.0 million relating to general casualty liabilities (compared to $62.5 million in 2014 ), $243.4 million relating to workers' compensation liabilities (compared to $63.6 million in 2014 ) and $97.7 million relating to all other remaining liabilities (compared to $70.7 million in 2014 ). The reduction in net IBNR reserves of $377.7 million relating to prior periods was a result of the application, on a basis consistent with the assumptions applied in the prior period, o f our actuarial methodologies to revised historical loss development data, following 79 commutations and policy buy-backs, to estimate loss reserves required to cover liabilities for unpaid losses and LAE relating to non-commuted exposures. The prior period estimate of net IBNR reserves was reduced as a result of the combined impact on all classes of business of loss development activity during 2015 , including commutations and the favorable trend of loss development related to non-commuted policies compared to prior forecasts. The net incurred loss development resulting from settlement of net advised case and LAE reserves of $366.3 million for net paid losses of $501.2 million related to the settlement of non-commuted losses in the year and 79 commutations and policy buy-backs of assumed and ceded exposures (including the commutation of two of our top ten assumed exposures and one of our top ten ceded recoverables as at January 1, 2014). Net advised case and LAE reserves settled by way of commutation and policy buy-back during the year ended December 31, 2015 amounted to $56.6 million (comprising $140.3 million of assumed case reserves and LAE reserves partially offset by $83.7 million of ceded incurred reinsurance recoverable case reserves). The reduction in provisions for bad debt of $25.3 million was a result of the collection of certain reinsurance recoverables against which bad debt provisions had been provided in earlier periods, and the reduction in bad debt provisions for insolvent reinsurers as a result of dividends received, partially offset by additional provisions for contractual disputes with reinsurers. Year Ended December 31, 2014 The net reduction in incurred losses and LAE for the year ended December 31, 2014 of $ 264.7 million included current period incurred losses of $24.2 million related to SeaBright. Excluding SeaBright's current period net incurred losses and LAE of $24.2 million net incurred losses and LAE relating to prior periods were reduced by $288.9 million which was attributable to a reduction in estimates of net ultimate losses of $235.8 million and a reduction in provisions for unallocated LAE of $49.4 million , relating to 2014 run-off activity, partially offset by an increase in provisions for bad debt of $7.7 million and the amortization of fair value adjustments over the estimated payout period relating to companies acquired amounting to $4.0 million . The reduction in estimates of net ultimate losses relating to prior periods of $235.8 million comprised reductions in net IBNR reserves of $262.4 million partially offset by net incurred loss development of $26.6 million . The decrease in the estimate of net IBNR reserves of $262.4 million (compared to $265.2 million during the year ended December 31, 2013 ) was comprised of $59.4 million relating to asbestos liabilities (compared to $69.8 million in 2013 ), $6.2 million relating to environmental liabilities (compared to $4.9 million in 2013 ), $62.5 million relating to general casualty liabilities (compared to $42.6 million in 2013 ), $63.6 million relating to workers' compensation liabilities (compared to $42.1 million in 2013 ) and $70.7 million relating to all other remaining liabilities (compared to $105.8 million in 2013 ). The reduction in net IBNR reserves of $262.4 million relating to prior periods was a result of the application, on a basis consistent with the assumptions applied in the prior period, of our actuarial methodologies to revised historical loss development data, following 98 commutations and policy buy-backs, to estimate loss reserves required to cover liabilities for unpaid losses and LAE relating to non-commuted exposures. The prior period estimate of net IBNR reserves was reduced as a result of the combined impact on all classes of business of loss development activity during 2014 , including commutations and the favorable trend of loss development related to non-commuted policies compared to prior forecasts. The net incurred loss development resulting from settlement of net advised case and LAE reserves of $285.8 million for net paid losses of $312.4 million related to the settlement of non-commuted losses in the year and 98 commutations and policy buy-backs of assumed and ceded exposures (including the commutation of one of our top ten assumed exposures and one of our top ten ceded recoverables as at January 1, 2013). Net advised case and LAE reserves settled by way of commutation and policy buy-back during the year ended December 31, 2014 amounted to $29.1 million (comprising $99.5 million of assumed case reserves and LAE reserves partially offset by $70.4 million of ceded incurred reinsurance recoverable case reserves). The increase in provisions for bad debt of $7.7 million was a result of additional provisions being allowed for contractual disputes with reinsurers, offset by cash collections and commutations on certain reinsurance recoverables against which bad debt provisions had been provided in earlier periods. Asbestos and Environmental In establishing the reserves for losses and LAE related to asbestos and environmental claims, management considers facts currently known and the current state of the law and coverage litigation. Liabilities are recognized for known claims (including the cost of related litigation) when sufficient information has been developed to indicate the involvement of a specific insurance policy, and management can reasonably estimate its liability. In addition, reserves have been established to cover additional exposures on both known and unreported claims. Estimates of the reserves are reviewed and updated continually. Developed case law and claim histories are still evolving for such claims, especially because significant uncertainty exists about the outcome of coverage litigation and whether past claim experience will be representative of future claim experience. In view of the changes in the legal and tort environment that affect the development of such claims, the uncertainties inherent in valuing asbestos and environmental claims are not likely to be resolved in the near future. Ultimate values for such claims cannot be estimated using traditional reserving techniques and there are significant uncertainties in estimating the amount of our potential losses for these claims. There can be no assurance that the reserves established by us will be adequate or will not be adversely affected by the development of other latent exposures. The liability for unpaid losses and LAE as of December 31, 2016 and 2015 included $921.2 million and $356.6 million , respectively, which represented an estimate of the net ultimate liability for asbestos and environmental claims. The gross liability for such claims as at December 31, 2016 and 2015 was $951.1 million and $390.8 million , respectively. Disclosures of Incurred and Paid Loss Development, IBNR, Claims Counts and Payout Percentages The following table provides a breakdown of the gross and net losses and LAE reserves by major category as at December 31, 2016: 2016 2016 Gross Net OLR IBNR Total OLR IBNR Total (in thousands of U.S. dollars) Asbestos $ 240,863 $ 548,180 $ 789,043 $ 230,983 $ 533,361 $ 764,344 Environmental 94,432 67,646 162,078 91,362 65,507 156,869 General casualty 427,733 316,227 743,960 301,699 190,053 491,752 Workers' compensation/personal accident 1,360,743 693,585 2,054,328 915,704 457,119 1,372,823 Marine, aviation and transit 45,240 34,873 80,113 39,816 34,678 74,494 Construction defect 39,622 120,459 160,081 32,449 88,647 121,096 Other 407,490 100,934 508,424 325,734 95,411 421,145 Total $ 2,616,123 $ 1,881,904 $ 4,498,027 $ 1,937,747 $ 1,464,776 $ 3,402,523 ULAE 218,336 218,336 Total $ 4,716,363 $ 3,620,859 As noted in the table above, the significant categories within this segment include asbestos, general casualty and workers’ compensation, which collectively comprised approximately 80% and 77% of the total gross and net reserves as at December 31, 2016. Separate claims development tables have been provided for the workers’ compensation and general casualty categories as set forth below. The asbestos category is wholly comprised of losses with accident years before 2007 and therefore accident year claims development tables are excluded from these disclosures. The exposures included in the other category includes losses with several different development patterns that are not individually sufficiently significant to be disclosed in separate claims development tables. Our non-life run-off segment is unique within the insurance industry. Legacy reserves are continuously being acquired into this segment through company acquisition or through loss portfolio transfer reinsurance. The loss development tables in this segment include actual loss development as well as the effects of assimilating newly acquired reserves. Accordingly, it would not be appropriate to extrapolate redundancies or deficiencies into the future or to infer actual historical accident year development information from the tables provided below. Acquired reserves for company acquisitions are shown on a full retrospective basis. Assumed reserves for loss portfolio reinsurance transactions are shown as follows: (i) unpaid reported claims are shown on a full retrospective basis and (ii) assumed IBNR is shown on a prospective basis as historical IBNR is generally not available to us in these transactions. For further information, we have disclosed additional development tables for reported claims, for IBNR, and for IBNR acquired in loss portfolio reinsurance transactions. General Casualty The following tables set forth information about incurred and paid loss development information related to our general casualty category within the Non-life Run-off segment as at December 31, 2016. The information related to incurred and paid loss development for the years ended December 31, 2007 through 2015 is presented as supplementary information and is unaudited. Unpaid Reported Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) 2007 $ 22,745 $ 26,555 $ 13,847 $ 10,053 $ 15,084 $ 8,757 $ 7,411 $ 6,302 $ 1,929 $ 2,679 2008 43,164 55,854 36,785 29,183 21,275 16,296 11,239 9,138 7,890 2009 19,205 37,028 45,685 34,708 22,834 15,044 14,562 11,333 2010 41,785 92,211 81,789 59,566 42,088 35,806 23,460 2011 19,805 48,609 33,465 32,499 25,227 19,945 2012 44,029 56,594 53,386 37,651 34,804 2013 20,677 23,432 22,681 16,995 2014 10,489 12,537 10,022 2015 3,294 4,356 2016 — 248 Total $ 131,732 IBNR Losses and Loss Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) 2007 $ 8,983 $ 8,409 $ 6,108 $ 6,339 $ 7,485 $ 2,986 $ 3,996 $ 3,356 $ 1,049 $ 1,579 2008 16,731 4,956 15,134 12,253 5,605 7,528 6,491 8,450 4,682 2009 14,131 16,784 15,393 8,240 12,272 9,170 5,363 5,247 2010 22,364 25,904 16,032 28,064 19,770 13,513 18,026 2011 33,180 23,948 34,767 25,659 18,042 20,683 2012 61,807 64,756 45,872 19,383 21,224 2013 70,755 58,446 17,200 16,534 2014 32,309 12,839 9,894 2015 7,697 7,573 2016 2,226 Total $ 107,668 The table below provides a summary of IBNR acquired in assumed loss portfolio transfer reinsurance transactions which is reflected on a prospective basis in the table above from the year in which the transaction occurred: For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) Take-On IBNR for Assumed Business $ — $ 10,740 $ — $ 3,633 $ — $ 25,703 $ — $ 5,263 $ 3,685 $ 36,501 Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 50,012 $ 69,095 $ 77,504 $ 81,587 $ 92,460 $ 86,583 $ 89,022 $ 87,929 $ 86,364 $ 88,081 2008 78,187 114,684 137,678 145,526 147,317 152,589 155,177 158,178 155,909 2009 47,683 95,064 128,373 146,500 164,233 168,363 173,304 173,855 2010 82,340 169,525 200,723 229,345 235,009 260,599 270,864 2011 73,694 134,667 166,450 177,382 186,384 191,245 2012 147,850 225,566 257,655 255,667 280,266 2013 117,545 135,171 113,574 122,148 2014 48,808 39,072 42,370 2015 12,949 16,292 2016 2,690 Total $ 1,343,720 Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For The Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 18,284 $ 34,131 $ 57,548 $ 65,195 $ 69,892 $ 74,840 $ 77,614 $ 78,271 $ 83,386 $ 83,823 2008 18,292 53,874 85,759 104,090 120,437 128,766 137,448 140,589 143,337 2009 14,347 41,253 67,294 103,552 129,127 144,148 153,379 157,275 2010 18,191 51,410 102,903 141,715 173,150 211,280 229,377 2011 20,709 62,110 98,218 119,224 143,116 150,616 2012 42,014 104,216 158,397 198,634 224,238 2013 26,112 53,293 73,693 88,618 2014 6,010 13,696 22,454 2015 1,958 4,364 2016 216 Total $ 1,104,318 All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance 266,163 Total outstanding liabilities for unpaid losses and LAE, net of reinsurance $ 505,565 The reconciliation of incurred and paid loss development to the liability for unpaid losses and LAE as presented in the tables above for the year ended December 31, 2016 is set forth below: December 31, 2016 Liabilities for unpaid losses and allocated LAE, net of re

Premiums Written and Earned

Premiums Written and Earned	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
PREMIUMS WRITTEN AND EARNED	REINSURANCE BALANCES RECOVERABLE The following table provides the total reinsurance balances recoverable as at December 31, 2016 and, 2015 : 2016 Non-life Run-off Atrium StarStone Life and Annuities Total Recoverable from reinsurers on unpaid: Outstanding losses $ 621,288 $ 6,438 $ 182,478 $ 190 $ 810,394 IBNR 393,550 21,753 178,259 — 593,562 Fair value adjustments (13,885 ) 1,818 (3,506 ) — (15,573 ) Total reinsurance reserves recoverable 1,000,953 30,009 357,231 190 1,388,383 Paid losses recoverable 47,160 (1,081 ) 25,512 769 72,360 $ 1,048,113 $ 28,928 $ 382,743 $ 959 $ 1,460,743 2015 Non-life Run-off Atrium StarStone Life and Annuities Total Recoverable from reinsurers on unpaid: Outstanding losses $ 587,164 $ 6,772 $ 182,076 $ 1,544 $ 777,556 IBNR 465,211 16,581 123,732 — 605,524 Fair value adjustments (17,628 ) 2,499 (6,025 ) — (21,154 ) Total reinsurance reserves recoverable 1,034,747 25,852 299,783 1,544 1,361,926 Paid losses recoverable 72,213 430 16,568 784 89,995 $ 1,106,960 $ 26,282 $ 316,351 $ 2,328 $ 1,451,921 Our insurance and reinsurance run-off subsidiaries, prior to acquisition, used retrocessional agreements to reduce their exposure to the risk of insurance and reinsurance assumed. On an annual basis, both Atrium and StarStone purchase a tailored outwards reinsurance program designed to manage their risk profiles. The majority of Atrium’s and StarStone's third-party reinsurance cover is with highly rated reinsurers or is collateralized by 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 discount rate equivalent to an interest rate for securities with similar duration to the reinsurance recoverables acquired including a spread to reflect credit risk, and are amortized over the estimated recovery period, as adjusted for accelerations in timing of payments as a result of commutation settlements. As of December 31, 2016 and 2015 , we had reinsurance balances recoverable of approximately $1.46 billion and $1.45 billion , respectively. The increase of $8.8 million in reinsurance balances recoverable was primarily a result of the additional coverage provided by KaylaRe Ltd., offset by commutations and cash collections made during the year ended December 31, 2016 in our Non-life Run-off and StarStone segments. Top Ten Reinsurers December 31, 2016 December 31, 2015 Non-life Atrium StarStone Life and Total % of Non-life Atrium StarStone Life and Total % of Top ten reinsurers $ 737,074 $ 23,245 $ 226,283 $ — $ 986,602 67.6 % $ 713,743 $ 21,394 $ 155,171 $ — $ 890,308 61.4 % Other reinsurers > $1 million 301,856 4,827 152,341 — 459,024 31.4 % 383,898 4,253 158,417 — 546,568 37.6 % Other reinsurers < $1 million 9,183 856 4,119 959 15,117 1.0 % 9,319 635 2,763 2,328 15,045 1.0 % Total $ 1,048,113 $ 28,928 $ 382,743 $ 959 $ 1,460,743 100.0 % $ 1,106,960 $ 26,282 $ 316,351 $ 2,328 $ 1,451,921 100.0 % The top ten external reinsurers, as at December 31, 2016 and 2015 , were all rated A- or better, with the exception of four non-rated reinsurers from which $512.2 million was recoverable ( December 31, 2015 : $337.6 million recoverable from three non-rated reinsurers). For the four non-rated reinsurers, we hold security in the form of pledged assets in trust, letters of credit issued to us, or funds withheld in the full amount of the recoverable. As at December 31, 2016 , reinsurance balances recoverable of $241.7 million and $154.7 million , respectively, related to KaylaRe Ltd. and Lloyd’s syndicates, both of which represent 10% or more of total reinsurance balances recoverable. Lloyd’s is rated ‘A+’ by Standard & Poor’s and ‘A’ by A.M. Best. KaylaRe Ltd. is not rated but is an affiliated company partly owned by Enstar, as described in Note 21 - "Related Party Transactions", and security is provided in the form of funds withheld. As at December 31, 2015 , reinsurance balances recoverable with a carrying value of $165.6 million related to Lloyd's syndicates and represented 10% or more of total reinsurance balances recoverable. Provisions for Uncollectible Reinsurance Recoverables We remain liable to the extent that retrocessionaires do not meet their obligations under these agreements, and therefore, we evaluate and monitor concentration of credit risk among our reinsurers. Provisions are made for amounts considered potentially uncollectible. The following table shows our reinsurance balances recoverable by rating of reinsurer and our provisions for uncollectible reinsurance balances recoverable ("provisions for bad debt") as at December 31, 2016 and 2015 . The provisions for bad debt all relate to the Non-life Run-off segment. 2016 2015 Gross Provisions for Bad Debt Net Provisions as a Gross Provisions for Bad Debt Net Provisions as a Reinsurers rated A- or above $ 892,776 $ 35,184 $ 857,592 3.9 % $ 1,029,844 $ 46,969 $ 982,875 4.6 % Reinsurers rated below A-, secured 544,894 — 544,894 — % 388,399 — 388,399 — % Reinsurers rated below A-, unsecured 197,589 139,332 58,257 70.5 % 244,005 163,358 80,647 66.9 % Total $ 1,635,259 $ 174,516 $ 1,460,743 10.7 % $ 1,662,248 $ 210,327 $ 1,451,921 12.7 % PREMIUMS WRITTEN AND EARNED The following tables provide a summary of net premiums written and earned in our Non-life Run-off, Atrium, StarStone and Life and Annuities segments for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Premiums Written Premiums Earned Premiums Written Premiums Earned Premiums Written Premiums Earned Non-life Run-off Gross $ 17,316 $ 25,989 $ 38,704 $ 116,494 $ 12,818 $ 45,684 Ceded (8,114 ) (9,234 ) (16,110 ) (72,125 ) (2,546 ) (14,516 ) Net $ 9,202 $ 16,755 $ 22,594 $ 44,369 $ 10,272 $ 31,168 Atrium Gross $ 143,170 $ 140,438 $ 149,082 $ 149,310 $ 154,248 $ 153,816 Ceded (2,733 ) (16,022 ) (14,502 ) (14,635 ) (17,973 ) (17,871 ) Net $ 140,437 $ 124,416 $ 134,580 $ 134,675 $ 136,275 $ 135,945 StarStone Gross $ 854,699 $ 830,186 $ 824,714 $ 769,875 $ 512,219 $ 528,135 Ceded (206,663 ) (153,578 ) (196,287 ) (196,729 ) (113,045 ) (154,502 ) Net $ 648,036 $ 676,608 $ 628,427 $ 573,146 $ 399,174 $ 373,633 Life and Annuities Life $ 6,261 $ 5,735 $ 1,553 $ 1,554 $ 2,235 $ 2,245 Total $ 803,936 $ 823,514 $ 787,154 $ 753,744 $ 547,956 $ 542,991

Goodwill, Intangible Assets and

Goodwill, Intangible Assets and Deferred Charges	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Intangible Assets and Deferred Charges	GOODWILL, INTANGIBLE ASSETS AND DEFERRED CHARGES The following tables present a reconciliation of the beginning and ending goodwill, intangible assets and deferred charges for the years ended December 31, 2016 and 2015 : 2016 Goodwill Intangible assets with a definite life - Other Intangible assets with an indefinite life Total Intangible assets with a definite life - FVA Other assets - Deferred Charges Balance as at January 1, 2016 $ 73,071 $ 31,202 $ 87,031 $ 191,304 $ 127,170 $ 255,911 Acquired during the year — — — — 37,005 7,467 Amortization — (6,449 ) — (6,449 ) (19,017 ) (168,827 ) Balance as at December 31, 2016 $ 73,071 $ 24,753 $ 87,031 $ 184,855 $ 145,158 $ 94,551 2015 Goodwill Intangible assets with a definite life - Other Intangible assets with an indefinite life Total Intangible assets with a definite life - FVA Other assets - Deferred Charges Balance as at January 1, 2015 $ 73,071 $ 41,048 $ 87,031 $ 201,150 $ 97,623 $ — Acquired during the year — — — — 23,968 271,176 Amortization — (9,846 ) — (9,846 ) 5,579 (15,265 ) Balance as at December 31, 2015 $ 73,071 $ 31,202 $ 87,031 $ 191,304 $ 127,170 $ 255,911 Goodwill as at December 31, 2016 and 2015 , related to Non-life Run-off, Atrium and StarStone, was $21.2 million , $38.9 million and $13.0 million , respectively. For the year ended December 31, 2016 , we completed our assessment for impairment of goodwill and concluded that there had been no impairment of our carried goodwill amount. Intangible assets with a definite life - Other includes the distribution channel, Lloyd’s capacity, technology and brand related to our acquisitions of Atrium and StarStone. These assets are amortized on a straight-line basis over a period ranging from four to fifteen years. Intangible asset amortization for the years ended December 31, 2016 , 2015 and 2014 was $6.4 million , $9.8 million and $6.0 million , respectively. Amortization for the year ended December 31, 2015 included an impairment charge of $4.0 million for the Torus brand in relation to the StarStone rebranding exercise. Intangible assets with an indefinite life includes assets associated with the Lloyd’s syndicate capacity for StarStone and Atrium, StarStone's U.S. insurance licenses, and Atrium’s management contract with Syndicate 609 in relation to underwriting, actuarial and support services it provides. Intangible assets with a definite life - fair value adjustments ("FVA") relates to outstanding losses and LAE, unearned premiums, other liabilities, reinsurance recoverables and other assets. These are included as a component of each balance sheet item. FVA are amortized in proportion to the recovery period for outstanding losses and LAE and reinsurance recoverables and as the unearned premiums expire for business in-force as of the acquisition date. Intangible asset amortization (accretion) of fair value adjustments for the years ended December 31, 2016 , 2015 and 2014 was $19.0 million , $(5.6) million and $(9.8) million , respectively. The FVA acquired during the year ended December 31, 2016 related to other assets and other liabilities in our acquisition of Dana, as described in Note 3 - “Acquisitions” and Note 23 - “Commitments and Contingencies”. Other assets - deferred charges relate to retroactive reinsurance policies providing indemnification of losses and LAE with respect to past loss events. At the inception of a contract, a deferred charge asset is recorded for the excess, if any, of the estimated ultimate losses payable over the premiums received. These amounts relate to the transactions with Voya Financial, Sun Life and Coca-Cola, described in Note 4 - "Significant New Business". Amortization of the deferred charges included $130.2 million and $15.3 million related to a reduction in the liability for losses and LAE for the years ended December 31, 2016 and December 31, 2015, respectively, and $38.6 million primarily related to a change in the expected return on the underlying assets for the year ended December 31, 2016. The gross carrying value, accumulated amortization and net carrying value of intangible assets by type and deferred charge at December 31, 2016 and 2015 were as follows: 2016 2015 Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value Intangible assets with a definite life: Fair value adjustments: Losses and LAE liabilities $ 458,202 $ (334,475 ) $ 123,727 $ 456,110 $ (307,785 ) $ 148,325 Reinsurance balances recoverable (175,924 ) 160,350 (15,574 ) (175,774 ) 154,619 (21,155 ) Other Assets (48,840 ) $ — (48,840 ) $ — $ — $ — Other Liabilities 85,845 $ — 85,845 $ — $ — $ — Total $ 319,283 $ (174,125 ) $ 145,158 $ 280,336 $ (153,166 ) $ 127,170 Other: Distribution channel $ 20,000 $ (4,111 ) $ 15,889 $ 20,000 $ (2,777 ) $ 17,223 Technology 15,000 (10,978 ) 4,022 15,000 (6,561 ) 8,439 Brand 7,000 (2,158 ) 4,842 12,000 (6,460 ) 5,540 Total $ 42,000 $ (17,247 ) $ 24,753 $ 47,000 $ (15,798 ) $ 31,202 Intangible assets with an indefinite life: Lloyd’s syndicate capacity $ 37,031 $ — $ 37,031 $ 37,031 $ — $ 37,031 Licenses 19,900 — 19,900 19,900 — 19,900 Management contract 30,100 — 30,100 30,100 — 30,100 Total $ 87,031 $ — $ 87,031 $ 87,031 $ — $ 87,031 Deferred charges on retroactive reinsurance $ 278,643 $ (184,092 ) $ 94,551 271,176 (15,265 ) 255,911 The table above excludes fair value adjustments of $ 46.5 million and $53.6 million as at December 31, 2016 and 2015, respectively, relating to policy benefits for life and annuity contracts relating to our Pavonia operations which are classified as held-for-sale. Amortization of fair value adjustments relating to Pavonia was $7.0 million and $ 7.9 million during the years ended December 31, 2016 and 2015, respectively. The estimated amortization expense for each of the five succeeding fiscal years related to our intangible assets with a definite life is as follows: Year Non-life Run-off Atrium StarStone Total 2017 $ 9,274 $ (504 ) $ 2,761 $ 11,531 2018 $ 9,524 $ 469 $ 315 $ 10,308 2019 $ 10,178 $ 1,056 $ (380 ) $ 10,854 2020 $ 10,294 $ 1,346 $ (231 ) $ 11,409 2021 $ 9,682 $ 1,620 $ (140 ) $ 11,162

Loans Payable

Loans Payable	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Loans Payable	LOANS PAYABLE We utilize debt facilities primarily for acquisitions and, from time to time, for general corporate purposes. Under these facilities, loans payable as of December 31, 2016 and 2015 were as follows: Facility Origination Date Term 2016 2015 EGL Revolving Credit Facility September 16, 2014 5 years $ 535,103 $ 505,750 Sussex Facility December 24, 2014 4 years 63,500 94,000 EGL Term Loan Facility November 18, 2016 3 years 75,000 — Total loans payable $ 673,603 $ 599,750 During the year ended December 31, 2016 , we utilized $571.0 million and repaid $493.3 million under our facilities. The facilities were primarily utilized for funding acquisitions and significant new business as described in Note 3 - "Acquisitions" and Note 4 - "Significant New Business," respectively. For the years ended December 31, 2016 , 2015 and 2014 , interest expense was $20.6 million , $19.4 million and $12.9 million , respectively, on our loan facilities. EGL Revolving Credit Facility This 5 -year revolving credit facility, originated on September 16, 2014, and most recently amended on August 5, 2016, is among the Parent Company and certain of its subsidiaries, as borrowers and as guarantors, and various financial institutions. We are permitted to borrow up to an aggregate of $665.0 million and we have an option to obtain additional commitments of up to $166.25 million . The individual outstanding loans under this facility are short-term loans, and the fair values of these loans approximate their book values. As of December 31, 2016 , there was $129.9 million of available unutilized capacity under this facility. Subsequent to December 31, 2016 , we utilized $90.0 million and repaid $34.0 million bringing the available unutilized capacity under this facility to $73.9 million . Interest is payable at least every six months at a LIBOR rate plus a margin and utilization fee as set forth in the credit facility agreement. The margin could vary based upon any change in our long term senior unsecured debt rating assigned by Standard & Poor’s Ratings Services or Fitch Ratings Ltd. We also pay a commitment fee for any unutilized portion of the facility. In the event of default, the interest rate may increase and the agent may cancel lender commitments and may demand early repayment. Financial and business covenants imposed on us include certain limitations on mergers and consolidations, acquisitions, indebtedness and guarantees, restrictions as to dispositions of stock and assets, and limitations on liens. Generally, the financial covenants require us to maintain a gearing ratio of consolidated indebtedness to total capitalization of not greater than 0.35 to 1.0 and to maintain a consolidated tangible net worth of not less than the aggregate of (i) $1.5 billion , (ii) 50% of positive net income since June 30, 2014, and (iii) 75% of the proceeds of any common stock issuance. In addition, the weighted-average credit rating of our cash and fixed maturity investments must be "BBB" or greater at all times. We are in compl iance with the covenants of the EGL Revolving Credit Facility. We borrowed €75.0 million under the facility during 2016 that was designated as a non-derivative hedge of our net investment in certain subsidiaries whose functional currency is denominated in Euros. The foreign exchange effect of revaluing these Euro borrowings resulted in a gain of $6.0 million recognized in the currency translation adjustment within accumulated other comprehensive income (loss) for the year ended December 31, 2016 , respectively. These amounts were offset against equivalent amounts recognized upon the translation of those subsidiaries' financial statements from functional currency into U.S. dollars. There were no ineffective portions of the net investment hedge during the year ended December 31, 2016 , which would have required reclassification from accumulated other comprehensive income (loss) into earnings. Sussex Facility On December 24, 2014, we entered into a four -year term loan (the "Sussex Facility", formerly called the Companion Facility) with two financial institutions. This facility was fully utilized to borrow $109.0 million to fund 50% of the consideration payable for the acquisition of Sussex, which was completed on January 27, 2015 . During the years ended December 31, 2016 and 2015, we repaid $30.5 million and $15.0 million of the outstanding principal under this facility. Interest is payable at least every six months at a LIBOR rate plus a margin as set forth in the loan agreement. In the event of default, the interest rate may increase and early repayment may be demanded, or the lender could proceed against the security. This facility is secured by a first priority interest in all of the assets and stock of Sussex. Financial and business covenants imposed on Sussex include limitations on mergers and consolidations, acquisitions, indebtedness and guarantees, restrictions as to dispositions of stock and assets (except for certain permitted dispositions), restrictions on dividends, and limitations on liens. Generally, the financial covenants require Sussex to (i) maintain statutory surplus of at least 1.1 times the authorized control level under the NAIC's risk-based capital calculation and at least 2 times the outstanding loan balance; and (ii) maintain certain characteristics of its investment portfolio relating to average credit quality and concentration. We are in compliance with the covenants of the Sussex Facility. EGL Term Loan Facility On November 18, 2016, we entered into and fully utilized a three -year $75.0 million unsecured term loan (the "EGL Term Loan Facility"). Interest is payable at least every three months at either (i) a base rate plus a margin or (ii) a LIBOR rate plus a margin as set forth in the loan agreement. In the event of default, an interest rate increase and early repayment may be demanded. Financial and business covenants imposed on us include certain limitations on mergers, consolidations, acquisitions, indebtedness and guarantees, restrictions on dividends, and limitations on liens. We are also required to maintain an average credit quality in our fixed income investment portfolio of BBB or its equivalent, and certain of our subsidiaries are restricted from engaging in certain derivative transactions without lender consent. The covenants require our regulated insurance subsidiaries to maintain capital resources of at least 1.1 times the amount required to meet solvency requirements.

Noncontrolling Interests

Noncontrolling Interests	12 Months Ended
	Dec. 31, 2016
Noncontrolling Interest [Abstract]
Noncontrolling Interests	NONCONTROLLING INTERESTS Redeemable Noncontrolling Interest Redeemable noncontrolling interest ("RNCI") as of December 31, 2016 comprises the ownership interest held by Trident ( 39.32% ) and Dowling ( 1.71% ) in North Bay Holdings Limited ("North Bay"). On December 23, 2015, we completed a corporate reorganization of certain of our subsidiary holding companies. Following the reorganization, StarStone Holdings and Northshore are owned by a common parent, North Bay. Northshore owns 100% of Atrium and Arden. StarStone Holdings owns 100% of StarStone and all of the interests in a segregated cell of one of our non-life run-off subsidiaries that reinsured all of StarStone’s non-life run-off reserves with effect from January 1, 2014. The following is a reconciliation of the beginning and ending carrying amount of the equity attributable to the RNCI for the years ended December 31, 2016 and 2015 : 2016 2015 Balance at beginning of year $ 417,663 $ 374,619 Capital contributions — 15,728 Dividends paid — (16,128 ) Net earnings (loss) attributable to RNCI 40,639 (8,797 ) Accumulated other comprehensive income (loss) attributable to RNCI 651 (745 ) Transfer from noncontrolling interest — 15,801 Change in redemption value of RNCI (4,431 ) 37,185 Balance at end of year $ 454,522 $ 417,663 We have carried the RNCI at its estimated redemption value, which is fair value, as of December 31, 2016 . The decrease was primarily attributable to a decrease in comparable company market valuations. On June 30, 2015, Trident contributed $15.7 million to StarStone Holdings. The transfer from noncontrolling interest in 2015 related to Dowling's interest. It was transferred to RNCI on December 31, 2015 following the corporate reorganization. Refer to Note 2 - "Significant Accounting Policies," Note 3 - "Acquisitions," Note 21 - "Related Party Transactions" and Note 23 - "Commitments and Contingencies" for additional information regarding RNCI. Noncontrolling Interest As of December 31, 2016 , we had $ 8.5 million of noncontrolling interest ("NCI") primarily related to an external interest in one of our non-life run-off subsidiaries. A reconciliation of the beginning and ending carrying amount of the equity attributable to NCI is included in the Consolidated Statement of Changes in Shareholders Equity. During 2015, we made the following repurchases of NCI: • On June 30, 2015, we entered into a Sale and Purchase Agreement with J.C. Flowers II L.P., J.C. Flowers II-A L.P., J.C. Flowers II-B, L.P. and Financial Service Opportunities L.P. (collectively, the "JCF II Funds"), pursuant to which we purchased all of the non-voting preference shares of Cumberland Holdings Ltd. and Courtenay Holdings Ltd., which represent all of the NCI owned directly by the JCF II Funds in our subsidiaries, for an aggregate price of $140.0 million . Immediately prior to the repurchase, the book value of the JCF II Funds’ NCI was $182.8 million . The transaction closed on September 30, 2015. • On September 3, 2015, we entered into a Sale and Purchase Agreement with Shinsei Bank, Limited ("Shinsei"), pursuant to which we purchased all of the Class B shares of Comox Holdings Ltd., which represents all of the NCI owned directly by Shinsei in our subsidiaries, for an aggregate price of $10.4 million . Immediately prior to the repurchase, the book value of Shinsei’s NCI was $12.5 million . The transaction closed on September 8, 2015. The difference between the price we paid and the book value of the NCI immediately prior to repurchase has been reflected as an increase to additional paid-in capital.

Share Capital

Share Capital	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Share Capital	SHARE CAPITAL As at December 31, 2016 and 2015 , the authorized share capital was 111,000,000 ordinary shares ("Voting Ordinary Shares") and non-voting convertible ordinary shares ("Non-Voting Ordinary Shares"), each of par value $1.00 per share, and 45,000,000 preference shares of par value $1.00 per share. The Voting Ordinary Shares are listed and trade on the NASDAQ Global Select Market. Each Voting Ordinary Share entitles the holder thereof to one vote. In accordance with the bye-laws, any U.S. shareholder or direct foreign shareholder group whose shares constitute 9.5% or more of the voting power of the Voting Ordinary Shares is entitled to less than one vote for each Voting Ordinary Share held by it. The Non-Votin g Ordinary Shares are comprised of several different series as of December 31, 2016 : • The Series A shares were issued and held in treasury, but were not outstanding. These shares were canceled in June 2016 in an internal reorganization as described below. • The Series C shares were originally issued in connection with investment transactions in April and December of 2011. The Series C shares: (i) have all of the economic rights (including dividend rights) attaching to Voting Ordinary Shares but are non-voting except in certain limited circumstances; (ii) will automatically convert at a one -for-one exchange ratio (subject to adjustment for share splits, dividends, recapitalizations, consolidations or similar transactions) into Voting Ordinary Shares if the registered holder transfers them in a widely dispersed offering; (iii) may only vote on certain limited matters that would constitute a variation of class rights and as required under Bermuda law, provided that the aggregate voting power of the Series C shares with respect to any merger, consolidation or amalgamation will not exceed 0.01% of the aggregate voting power of our issued share capital; and (iv) require the registered holders’ written consent in order to vary the rights of the shares in a significant and adverse manner. • The Series B and Series D shares were created in connection with the 2011 investment transactions, but no shares in these series are issued and outstanding. Holders of the Series C shares have the right to convert such shares, on a share-for-share basis, subject to certain adjustments, into Series D shares at their option. There is no economic difference in Series B, C or D shares, but there are slight differences in the conversion rights and the limited voting rights of each series. • There were 404,771 Series E shares issued and outstanding as of December 31, 2016 . There were 714,015 Series E shares originally issued and outstanding in connection with the acquisition of StarStone. During 2015, 309,244 of the previously issued and outstanding Series E shares were converted into Voting Ordinary Shares upon market sales constituting a widely dispersed offering. The Series E shares have substantially the same rights as the Series C shares, except that (i) they are convertible only into Voting Ordinary Shares and (ii) they may only vote as required under Bermuda law. The Series E shares include all other Non-Voting Ordinary Shares authorized under our bye-laws but not classified as Series A, B, C or D Non-Voting Ordinary Shares. As of December 31, 2016 , there were warrants outstanding to acquire 175,901 Series C Non-Voting Ordinary Shares for an exercise price of $115.00 per share, subject to certain adjustments (the "Warrants"). The Warrants were issued in April 2011 and expire in April 2021. The Warrant holder may, at its election, satisfy the exercise price of the Warrants on a cashless basis by surrender of shares otherwise issuable upon exercise of the Warrants in accordance with a formula set forth in the Warrants. During December 2016, 164,919 Warrants were exercised on a cashless basis, resulting in the issuance of 66,520 Series C Non-Voting Ordinary Shares. In a series of transactions that took place subsequent to December 31, 2016 , 192,485 Series C Non-Voting Ordinary Shares converted into Voting Ordinary Shares in a widely dispersed offering by their registered holders. As of December 31, 2016 , there were 388,571 Series C Participating Non-Voting Perpetual Preferred Stock ("Series C Preferred Shares") issued and held by one of our wholly-owned subsidiaries. The Series C Preferred Shares were issued in June 2016 in an internal reorganization transaction that resulted in the cancellation of all of the Series A Shares, which had an equivalent value and were also previously held by our wholly-owned subsidiary. The Series C Preferred Shares (i) upon liquidation, dissolution or winding up of the Company, entitle their holders to a preference over holders of our ordinary voting and non-voting shares of an amount equal to $0.001 per share with respect to surplus assets and (ii) are non-voting except in certain limited circumstances. The Series C Preferred shares have dividend rights equal to those of the ordinary voting shares, subject to certain limitations and in an amount determined by a "participation rate" that is generally reflective of the reduction in the number of Series C Preferred Shares issued in exchange for the previously outstanding Series A Shares. The Series C Preferred Shares otherwise rank on parity with the ordinary voting and non-voting shares, and they rank senior to each other class or series of share capital, unless the terms of any such class or series shall expressly provide otherwise. There were 714,015 Series B Convertible Participating Non-Voting Perpetual Preferred Stock, par value 1.00 per share (the “Non-Voting Preferred Shares”) issued and converted into Series E shares during 2014 in connection with our acquisition of StarStone.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The following table sets forth the computation of basic and diluted earnings per share for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Numerator: Net earnings from continuing operations $ 252,844 $ 222,322 $ 208,210 Net earnings (losses) from discontinuing operations 11,963 (2,031 ) 5,539 Net earnings attributable to Enstar Group Limited $ 264,807 $ 220,291 $ 213,749 Denominator: Weighted-average ordinary shares outstanding — basic 19,299,426 19,252,072 18,409,069 Effect of dilutive securities: Restricted shares 31,434 63,900 57,184 Restricted share units 16,994 12,901 15,986 Warrants 99,387 78,883 58,957 Preferred shares — — 136,934 Weighted-average ordinary shares outstanding — diluted 19,447,241 19,407,756 18,678,130 Earnings per share attributable to Enstar Group Limited: Basic: Net earnings from continuing operations $ 13.10 $ 11.55 $ 11.31 Net earnings (loss) from discontinuing operations 0.62 (0.11 ) 0.30 Net earnings per ordinary share $ 13.72 $ 11.44 $ 11.61 Diluted: Net earnings from continuing operations $ 13.00 $ 11.46 $ 11.15 Net earnings (loss) from discontinuing operations 0.62 (0.11 ) 0.29 Net earnings per ordinary share $ 13.62 $ 11.35 $ 11.44

Share-Based Compensation and Pe

Share-Based Compensation and Pensions	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Share-Based Compensation and Pensions	SHARE-BASED COMPENSATION AND PENSIONS Share-based compensation Employee share awards have been granted under the 2016 and 2006 Equity Incentive Plans. Restricted Shares and Restricted Share Units Restricted shares and restricted share units are service awards that typically vest over three to four years. These awards are share-settled and are recorded in additional paid-in capital on the consolidated balance sheets. The fair value of these awards is measured at the grant date and expensed over the service period. The following ta ble summarizes the activity related to restricted shares and restricted share awards during 2016 : Number of Shares Weighted- Average Share Price of Award Nonvested — January 1 96,055 $ 150.04 Granted 44,165 182.98 Vested (44,925 ) 101.48 Forfeited (16,303 ) 141.09 Nonvested — December 31 78,992 165.94 Compensation costs of $3.0 million , $6.1 million and $3.9 million relating to these share awards were recognized in our statement of earnings for the years ended December 31, 2016 , 2015 and 2014 , respectively. The unrecognized compensation cost related to our non-vested share awards as at December 31, 2016 was $8.4 million . This cost is expected to be recognized over the next 2.0 years, which is the weighted average contractual life of the awards. Cash-Settled Stock Appreciation Rights Cash-settled stock appreciation right awards ("SARs") give the holder the right, upon exercise, to receive in cash the difference between the market price per share of our ordinary shares at the time of exercise and the exercise price of the SARs. The exercise price of each SAR is equal to the market price of our ordinary shares on the date of the grant. Vested SARs are exercisable for periods not to exceed either 4 years or 10 years from the date of grant. The following t able summarizes the activity related to SARs during 2016: Number of SARs Weighted- Average Exercise Price of SARs Weighted Average Expected Term (in years) Aggregate Intrinsic Value (1) Balance, beginning of year 1,160,828 $ 140.51 Exercised (92,458 ) 139.88 Forfeited (127,202 ) 139.58 Balance, end of year 941,168 140.70 1.94 $ 53,644 (1) The aggregate intrinsic value is calculated as the pre-tax difference between the exercise price of the underlying share awards and the closing price per share of our ordinary shares of $197.70 on December 31, 2016 . Compensation expense for SARs is based on the estimated fair value on the date of grant using the Black-Scholes valuation model, which requires the use of subjective assumptions related to the expected stock price volatility, expected term, expected dividend yield and risk-free interest rate. SARs are liability-classified awards for which compensation expense and the liability are re-measured using the then-current Black Scholes assumptions at each interim reporting date based upon the portion of the requisite service period rendered. Compensation costs of $35.6 million and $8.9 million relating to these share awards were recognized in our statement of earnings for the years ended December 31, 2016 and 2015 , respectively. The unrecognized compensation cost related to our SARs as at December 31, 2016 was $10.1 million . This cost is expected to be recognized over the next 0.53 years, which is the weighted-average remaining vesting term of the awards. The following table sets forth the assumptions used to estimate the fair value of the SARs using the Black-Scholes option valuation model as at December 31, 2016 and 2015 : 2016 2015 2014 Weighted-average fair value per SAR $ 62.39 $ 29.02 $ 37.63 Weighted-average volatility 19.82 % 22.08 % 21.24 % Weighted-average risk-free interest rate 1.12 % 1.29 % 0.81 % Dividend yield 0.00 % 0.00 % 0.00 % Performance Share Units ("PSUs") Subsequent to December 31, 2016, we granted 34,775 PSU's with a grant date fair value of $6.9 million . The PSU's are share-settled and vest on the third anniversary of the grant date. The number of shares to vest will be determined by a performance adjustment based on the change in fully diluted book value per share ("FDBVPS") over three years. An increase of 30% to 40% or more in FDBVPS results in a settlement of 100% to a maximum of 150% of the units granted, respectively. An increase of 20% to 30% in FDBVPS results in a settlement of 50% to 100% of the units granted, respectively. Straight-line interpolation applies within these ranges and no settlement occurs if the increase in FDBVPS is less than 20% . Other share-based compensation plans Northshore Incentive Plan Our subsidiary, Northshore, has long-term incentive plans that award time-based restricted shares of Northshore to certain Atrium employees. Shares generally vest over two to three years. These share awards have been classified as liability awards. For the years ended December 31, 2016 , 2015 , and 2014, compensation costs of $2.8 million , $3.9 million and $5.2 million relating to the long-term incentive plans were recorded in our consolidated statement of earnings. The unrecognized compensation cost related to the Northshore incentive plan at December 31, 2016 was $3.7 million . This cost is expected to be recognized over the next 1.76 years, which is the weighted average contractual life of the awards. Deferred Compensation and Ordinary Share Plan for Non-Employee Directors For the years ended December 31, 2016 , 2015 and 2014 , 4,298 , 5,174 and 3,716 restricted share units, respectively, were credited to the accounts of non-employee directors under the Enstar Group Limited Deferred Compensation and Ordinary Share Plan for Non-Employee Directors (the "Deferred Compensation Plan"). Expense related to the restricted share units for the years ended December 31, 2016 , 2015 and 2014 , was $0.7 million , $1.0 million and $0.5 million , respectively. During the years ended December 31, 2015 and 2014, 2,393 and 11,749 restricted share units, respectively, previously credited to the accounts of two directors under the Deferred Compensation Plan were converted into ordinary shares following their resignations. Also during 2014, 14,922 restricted share units previously credited to one of the retiring director's account under a previous deferred compensation plan were converted into the same number of our ordinary shares. Employee Share Purchase Plan For the years ended December 31, 2016 , 2015 and 2014 , compensation costs relating to the shares issued under the Amended and Restated Enstar Group Limited Employee Share Purchase Plan ("Share Plan") of $0.3 million , $0.3 million and $0.1 million , respectively, were recorded as salaries and benefits in our consolidated statement of earnings. For the years ended December 31, 2016 , 2015 and 2014 , 12,234 , 11,998 and 6,031 shares, respectively, were issued to employees under the Share Plan. Pension Plans We provide retirement benefits to eligible employees through various plans that we sponsor. Defined Contribution Plans Pension expense relating to defined contribution plans for the years ended December 31, 2016 , 2015 and 2014 was $10.8 million , $10.3 million and $9.2 million , respectively. Pension expense can be affected by changes in our employee headcount as a result of our acquisitions described in Note 3 - "Acquisitions." Defined Benefit Plan We have a noncontributory defined benefit pension plan that was acquired in the Providence Washington transaction in 2010. Pension expense relating to this defined benefit plan was $2.3 million , $0.6 million and $0.5 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. The increase in pension expense during 2016 was due to the completion of a lump sum buyout offering during 2016 and was offset by a reduction in accumulated other comprehensive loss in shareholders' equity. During 2016 , an actuarial review was performed, which determined that the plan’s unfunded liability, as at December 31, 2016 , was $10.3 million as compared to $12.1 million as at December 31, 2015 . As at December 31, 2016 and 2015, we had an accrued liability of $10.3 million and $12.1 million , respectively, for this p lan.

Taxation

Taxation	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Taxation	TAXATION Enstar Group Limited's Parent Company is incorporated under the laws of Bermuda and under Bermuda law is not required to pay taxes in Bermuda based upon income or capital gains. The Company, under the Exempted Undertakings Tax Protection Act of 1966, is protected against any legislation that may be enacted in Bermuda which would impose any tax on profits, income, or gain until March 31, 2035. We have foreign operating subsidiaries and branch operations principally located in the United States, United Kingdom, Continental Europe and Australia that are subject to federal, foreign, state and local taxes in those jurisdictions. Deferred income tax liabilities have not been accrued with respect to the undistributed earnings of our foreign subsidiaries. If the earnings were to be distributed, as dividends or other distributions, withholding taxes may be imposed by the jurisdiction of the paying subsidiary. For our U.S. subsidiaries, we have not currently accrued any withholding taxes with respect to un-remitted earnings as management has no current intention of remitting these earnings. For our United Kingdom subsidiaries, there are no withholding taxes imposed. For our other foreign subsidiaries, it would not be practicable to compute such amounts due to a variety of factors, including the amount, timing, and manner of any repatriation. Because we operate in many jurisdictions, our net earnings are subject to risk due to changing tax laws and tax rates around the world. The current, rapidly changing economic environment may increase the likelihood of substantial changes to tax laws in the jurisdictions in which we operate. The following table presents earnings before income taxes by jurisdiction from continuing operations : 2016 2015 2014 Domestic (Bermuda) $ 191,647 $ 61,695 $ 154,453 Foreign 135,677 163,327 72,845 Total earnings before income tax on continuing operations $ 327,324 $ 225,022 $ 227,298 The following table presents our current and deferred income tax expense (benefit) from continuing operations by jurisdiction: 2016 2015 2014 Current: Domestic (Bermuda) $ — $ — $ — Foreign 21,485 30,028 38,814 21,485 30,028 38,814 Deferred: Domestic (Bermuda) — — — Foreign 13,389 (17,378 ) (33,213 ) 13,389 (17,378 ) (33,213 ) Total tax expense on continuing operations $ 34,874 $ 12,650 $ 5,601 The actual income tax rate differs from the amount computed by applying the effective rate of 0% under Bermuda law to earnings from continuing operations before income taxes as shown in the following reconciliation: 2016 2015 2014 Earnings before income tax $ 327,324 $ 225,022 $ 227,298 Bermuda income taxes at statutory rate 0.0 % 0.0 % 0.0 % Foreign income tax rate differential 8.8 % 17.6 % 11.3 % Change in unrecognized tax benefits — % — % (1.0 )% Benefit of loss carryovers — % — % (1.3 )% Change in valuation allowance (0.1 )% (10.5 )% (13.2 )% Investment write-off — % — % 1.9 % Foreign currency translation — % (0.3 )% 0.8 % Other 2.0 % (1.2 )% 4.0 % Effective tax rate 10.7 % 5.6 % 2.5 % Our effective tax rate is driven by the geographical distribution of our pre-tax net earnings between our taxable and non-taxable jurisdictions. Deferred Tax Assets and Liabilities Deferred tax assets and liabilities reflect the tax effect of the differences between the financial reporting and income tax bases of assets and liabilities. Significant components of the deferred tax assets and deferred tax liabilities related to our continuing operations were as follows: As of December 31, 2016 2015 Deferred tax assets: Net operating loss carryforwards $ 262,271 $ 259,851 Tax credits and other carryforwards 7,487 6,354 Insurance reserves 19,265 29,682 Unearned premiums 8,760 6,821 Lloyd's underwriting losses taxable in future periods 6,581 17,768 Provisions for bad debt 16,018 17,694 Other deferred tax assets 7,946 3,532 Gross deferred tax assets 328,328 341,702 Valuation allowance (290,861 ) (291,280 ) Deferred tax assets 37,467 50,422 Deferred tax liabilities: Unrealized gains on investments (12,804 ) (10,567 ) Intangible assets (20,615 ) (20,895 ) Other deferred tax liabilities (21,030 ) (22,044 ) Deferred tax liabilities (54,449 ) (53,506 ) Net deferred tax liability $ (16,982 ) $ (3,084 ) As of December 31, 2016 , we had net operating loss carryforwards that could be available to offset future taxable income, as follows: Tax Jurisdiction Loss Carryforwards Tax effect Expiration Operating and Capital Loss Carryforwards: United States - Net operating loss $ 571,235 $ 193,670 2021-2033 United States - Capital loss 11,820 4,905 2021-2026 United Kingdom 280,707 57,381 None Other 30,098 6,152 None Tax Credits: United States alternative minimum tax $ 7,374 None Assessment of Valuation Allowance on Deferred Tax Assets As of December 31, 2016 and 2015 , we had deferred tax asset valuation allowances of $290.9 million and $291.3 million , respectively, related to foreign subsidiaries. The realization of deferred tax assets is dependent on generating sufficient taxable income in future periods in which the tax benefits are deductible or creditable. Taxes are determined and assessed jurisdictionally by legal entity or by filing group. Certain jurisdictions require or allow combined or consolidated tax filings. We have estimated future taxable income of our foreign subsidiaries and provided a valuation allowance in respect of those assets 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. Our assessment weighs both positive and negative evidence and considers the extent to which the evidence can be objectively verified. When negative evidence outweighs positive evidence then it can be difficult to support a conclusion that a valuation allowance is not needed. We consider the following evidence: (i) net earnings or losses in recent years; (ii) the future sustainability and likelihood of positive net earnings of our subsidiaries; (iii) the carryforward periods of tax losses including the effect of reversing temporary differences; and (iv) tax planning strategies. The decrease of $0.4 million in our continuing operations for 2016 related to the utilization of deferred tax assets for which we previously carried a valuation allowance, offset by additional valuation allowance for deferred tax assets management assessed as unable to meet the more-likely-than-not standard for utilization. Uncertainty in Income Taxes A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: 2016 2015 2014 Balance, beginning of year $ — $ — $ 2,249 Gross increases — tax positions related to prior years — — — Gross decreases — tax positions related to prior years — — — Lapse of statute of limitations — — (2,249 ) Balance, end of year $ — $ — $ — During the years ended December 31, 2016 , 2015 and 2014 , we recognized a benefit for the reversal of interest and penalties related to unrecognized tax benefits due to the expiration of the statute of limitations in the amount of $ nil , $ nil and $ 2.2 million , respectively. There were no accruals for the payment of interest and penalties related to unrecognized tax benefits at each of December 31, 2016 , 2015 and 2014 . Our operating subsidiaries may be subject to audit by various tax authorities and may have different statutes of limitations expiration dates. Tax authorities may propose adjustments to our income taxes. Listed below are the tax years that remain subject to examination by a major tax jurisdiction as of December 31, 2016 : Major Tax Jurisdiction Open Tax Years United States 2013-2015 United Kingdom 2013-2015 Australia 2011-2015

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS Stone Point Capital LLC Through several private transactions occurring from May 2012 to July 2012, Trident acquired 1,350,000 of our Voting Ordinary Shares (which now constitutes approximately 8.3% 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 Capital LLC ("Stone Point"), the manager of the Trident funds. In addition, we have entered into certain agreements with Trident with respect to Trident’s co-investments in the Atrium, Arden, and StarStone acquisitions. These include investors’ agreements and shareholders’ agreements, which provide for, among other things: (i) our right to redeem Trident’s equity interest in the Atrium/Arden and StarStone transactions in cash at fair market value within the 90 days following the fifth anniversary of the Arden and StarStone closings, respectively, and at any time following the seventh anniversary of the Arden and StarStone closings, respectively; and (ii) Trident’s right to have its equity co-investment interests in the Atrium/Arden and StarStone transactions redeemed by us at fair market value (which we may satisfy in either cash or our ordinary shares) following the seventh anniversaries of the Arden closing and StarStone closing, respectively. As of December 31, 2016 , we have included $454.5 million ( December 31, 2015 : $417.7 million ) as RNCI on our balance sheet relating to these Trident co-investment transactions. Pursuant to the terms of the shareholders’ agreements, Mr. Carey serves as a Trident representative on the boards of the holding companies 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. As at December 31, 2016 , we had investments in funds (carried within other investments) and a registered investment company affiliated with entities owned by Trident or otherwise affiliated with Stone Point. The fair value of the investments in the funds was $232.1 million and $237.9 million as of December 31, 2016 and December 31, 2015 , respectively, while the fair value of our investment in the registered investment company was $20.9 million and $21.0 million as at December 31, 2016 and December 31, 2015 , respectively. For the years ended December 31, 2016 and 2015 , we recognized net realized and unrealized gains of $17.2 million and net realized and unrealized losses of $0.1 million respectively, in respect of the fund investments, and net realized and unrealized losses of $0.4 million and $4.7 million , respectively, in respect of the registered investment company investment. For the years ended December 31, 2016 and 2015 , we recognized interest income of $3.1 million and $2.8 million in respect of the registered investment company. We also have separate accounts, with a balance of $215.0 million and $157.8 million as at December 31, 2016 and 2015, respectively, managed by Eagle Point Credit Management and PRIMA Capital Advisors, which are affiliates of entities owned by Trident, with respect to which we incurred approximately $0.5 million and $0.4 million in management fees for the years ended December 31, 2016 and 2015 , respectively. In addition, we are invested in two 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 director. The fair value of our investments in Sound Point Capital funds was $25.4 million and $34.5 million as of December 31, 2016 and December 31, 2015 , respectively; the decrease was primarily due to a partial sale of fund investment during the year ended December 31, 2016 . For the years ended December 31, 2016 and 2015 , we have recognized net realized and unrealized gains of $1.9 million and $0.6 million , respectively, in respect of investments managed by Sound Point Capital. Sound Point Capital has acted as collateral manager for certain of our direct investments in CLO equity securities. The fair value of these investments was $20.3 million and $18.2 million as at December 31, 2016 and December 31, 2015 , respectively. For the years ended December 31, 2016 and 2015, we recognized net realized and unrealized gains of $2.1 million and net realized unrealized losses of $3.6 million , respectively. For the years ended December 31, 2016 and 2015, we recognized interest income of $6.7 million and $3.4 million , respectively, in respect of these investments. We have a separate account managed by Sound Point Capital, with a balance of $61.2 million and $53.5 million as at December 31, 2016 and December 31, 2015, respectively, with respect to which we incurred approximately $0.3 million and $0.1 million in management fees for the years ended December 31, 2016 and 2015, respectively. Goldman Sachs & Co. Affiliates of Goldman, Sachs & Co. ("Goldman Sachs") previously owned approximately 4.1% of our Voting Ordinary Shares and 100% of our Series C Non-Voting Ordinary Shares ("Series C Shares"), which constituted an aggregate economic interest of approximately 17.5% (excluding the impact of Goldman Sachs' warrants to acquire additional Series C Non-Voting Ordinary Shares). During September 2016, Goldman Sachs affiliates: (i) sold a portion of their Voting Ordinary Shares, Series C Non-Voting Ordinary Shares, and warrants, following which they held an aggregate economic interest of approximately 8.5% and (ii) sold Series C Shares to Canada Pension Plan Investment Board ("CPPIB") that resulted in Goldman Sachs holding an aggregate economic interest of approximately 2.3% . In December 2016, we filed a registration statement at Goldman Sachs' expense, pursuant to which Goldman Sachs affiliates were permitted to offer their remaining Voting Ordinary Shares and Series C Shares for resale from time to time. In addition, Goldman Sachs affiliates completed a cashless exercise of their remaining warrants, which were exchanged for Series C Non-Voting Ordinary Shares and included under the registration statement. Sumit Rajpal, a managing director of Goldman Sachs, was appointed to our Board of Directors in connection with Goldman Sachs’ investment in Enstar; he resigned on September 16, 2016. As of December 31, 2016 and December 31, 2015 , we had investments in funds (carried within other investments) affiliated with entities owned by Goldman Sachs, which had a fair value of $ 19.3 million and $ 39.6 million , respectively. The decrease was primarily due to a sale of one of the fund investments during the year ended December 31, 2016 . As of December 31, 2016 and December 31, 2015 , we had an indirect investment in non-voting interests of two companies affiliated with Hastings Insurance Group Limited which had a fair value of $49.9 million and $44.6 million , respectively. Goldman Sachs affiliates have an approximately 38% interest in the Hastings companies, and Mr. Rajpal serves as a director of the entities in which we have invested. For the years ended December 31, 2016 and 2015 , we recognized net realized and unrealized gains of $ 20.6 million and $ 24.1 million and interest income of $1.7 million and $ nil , respectively, in respect of the Goldman Sachs-affiliated investments. A Goldman Sachs affiliate provides investment management services to one of our subsidiaries. Our interests are held in accounts managed by affiliates of Goldman Sachs, with a balance of $748.0 million and $758.9 million as at December 31, 2016 and December 31, 2015 respectively, with respect to which we incurred approximately $0.8 million and $0.6 million in management fees for the years ended December 31, 2016 and 2015, respectively. CPPIB CPPIB, together with management of Wilton Re, own 100% of the common stock of Wilton Re. Subsequent to the closing of our transaction with Wilton Re on June 3, 2015, CPPIB purchased voting and non-voting shares in Enstar from FR XI Offshore AIV, L.P., First Reserve Fund XII, L.P., FR XII-A Parallel Vehicle L.P. and FR Torus Co-Investment, L.P. On September 29, 2015, CPPIB exercised its acquired right to appoint a representative, Poul Winslow, to our Board of Directors. During November 2016, CPPIB acquired additional non-voting shares in Enstar from Goldman Sachs affiliates in a private transaction. Following this transaction, CPPIB's shares constitute an approximate 9.3% voting interest and an approximate 16% aggregate economic interest in Enstar. In addition, approximately 4.6% of our voting shares (constituting an aggregate economic interest of approximately 3.8% ) are held indirectly by CPPIB through CPPIB Epsilon Ontario Limited Partnership ("CPPIB LP"). CPPIB is the sole limited partner of CPPIB LP, and CPPIB Epsilon Ontario Trust ("CPPIB Trust") is the general partner. CPPIB's director representative is a trustee of CPPIB Trust. We also have a pre-existing reinsurance recoverable from a company later acquired by Wilton Re, which was carried on our balance sheet at $9.4 million as of December 31, 2016 . KaylaRe On December 15, 2016, our equity method investee, KaylaRe Holdings Ltd. ("KaylaRe") completed an initial capital raise of $620.0 million . We own approximately 48.4% of KaylaRe's common shares. We also have a warrant to purchase up to 900,000 common shares of KaylaRe, exercisable upon an initial public offering or listing of KaylaRe’s common shares at an exercise price of $20.00 per share. We have recorded the investment in KaylaRe using the equity method basis of accounting, pursuant to the conclusion that we are not required to consolidate following an analysis based on the guidance in ASC 810 - Consolidation . Our investment in the common shares and warrants of KaylaRe was carried at $294.6 million in other assets on our consolidated balance sheet as at December 31, 2016. In connection with our investment in KaylaRe, we entered into a Shareholders Agreement with the other shareholders in KaylaRe, including the Trident funds and HH KaylaRe Holdings, Ltd., an affiliate of Hillhouse Capital Management (“Hillhouse”). The Shareholders Agreement (i) provides us with the right to appoint one member to the KaylaRe Board of Directors until the date that we own less than 1,250,000 common shares, (ii) includes a five year lock-up period on common shares of KaylaRe (unless KaylaRe completes an initial public offering before the expiry of this five year lock-up period), (iii) provides customary tag-along rights and rights of first refusal in the case of certain proposed transfers by any other shareholder and customary preemptive rights in the event of a proposed new issuance of equity securities by KaylaRe. In the event that KaylaRe has not consummated an initial public offering by March 31, 2021, the Trident funds have the right to require us and Hillhouse to purchase on a pro rata basis all of their common shares in KaylaRe at the then-current fair market value. Our subsidiary, Enstar Limited, acts as insurance and reinsurance manager to KaylaRe's subsidiary, KaylaRe Ltd. Affiliates of Enstar have also entered into various reinsurance agreements with KaylaRe Ltd., and KaylaRe Ltd. will also have the opportunity to participate in future Enstar legacy transactions. We also provide administrative services to KaylaRe and KaylaRe Ltd. Through a Quota Share Agreement dated December 15, 2016, (the "KaylaRe-StarStone QS") several of our StarStone affiliates have entered into a Quota Share Treaty with KaylaRe Ltd. pursuant to which KaylaRe Ltd. reinsures 35% of all business written by these StarStone affiliates for risks attaching from January 1, 2016, net of the StarStone affiliates’ reinsurance programs. During the year ended December 31, 2016 , StarStone ceded $117.6 million of premium earned, $75.7 million of net incurred losses and LAE and $42.5 million of acquisition costs to KaylaRe Ltd under the KaylaRe-StarStone QS. These amounts were recorded in the aggregate as net incurred losses and LAE of $1.4 million in our consolidated statement of earnings for the year ended December 31, 2016 in accordance with retroactive reinsurance accounting. In addition, certain of our non-life run-off subsidiaries ceded $177.2 million of loss reserves to KaylaRe Ltd. during the year ended December 31, 2016, on a funds held basis. Our consolidated balance sheet as at December 31, 2016 included the following balances related to transactions between us and KaylaRe and KaylaRe Ltd.: reinsurance recoverable of $242.1 million , prepaid reinsurance premiums of $109.0 million , funds held of $182.3 million recorded in other liabilities, insurance and reinsurance balances payable of $132.6 million , and ceded acquisition costs of $41.2 million recorded as a reduction of deferred acquisition costs. Hillhouse Investment funds managed by Hillhouse collectively own approximately 2.1% of Enstar’s voting ordinary shares. These funds also own non-voting ordinary shares and warrants to purchase additional non-voting ordinary shares, which together with their voting ordinary shares, represent an approximate 9.8% economic interest in Enstar. As of December 31, 2016, our equity method investee, KaylaRe, had investments in a fund managed by Hillhouse with a fair value of $350.0 million .

Dividend Restrictions and Statu

Dividend Restrictions and Statutory Financial Information	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
Dividend Restrictions and Statutory Financial Information	DIVIDEND RESTRICTIONS AND STATUTORY FINANCIAL INFORMATION Parent Company Dividend Restrictions There were no significant restrictions on the Parent Company's ability to pay dividends from retained earnings as at December 31, 2016. Bermuda law permits the payment of dividends if (i) we are not, or would not be after payment, unable to pay our liabilities as the become due and (ii) the realizable value of our assets is in excess of our liabilities after taking such payment into account. Enstar has not historically declared a dividend. Our strategy is to retain earnings and invest distributions from our subsidiaries back into the company. We do not currently expect to pay any dividends on our ordinary shares. The Bermuda Monetary Authority ("BMA") acts as group supervisor to Enstar. On an annual basis, we are required to file group statutory financial statements, a group statutory financial return, a group capital and solvency return, audited group financial statements and a Group Solvency Self-Assessment ("GSSA") with the BMA. The GSSA is designed to document our perspective on the capital resources necessary to achieve our business strategies and remain solvent, and to provide the BMA with insights on our risk management, governance procedures and documentation related to this process. We are required to maintain available group statutory capital and surplus in an amount that is at least equal to the group enhanced capital requirement ("Group ECR"). The BMA has also established a group target capital level equal to 120% of the Group ECR. We are in compliance with these requirements. Our ability to pay dividends to our shareholders is dependent upon the ability of our insurance and reinsurance subsidiaries to distribute capital and pay dividends to us. Our insurance and reinsurance subsidiaries are subject to certain regulatory restrictions on the distribution of capital and payment of dividends in the jurisdictions in which they operate, as described below. The restrictions are generally based on net income or levels of capital and surplus as determined in accordance with the relevant statutory accounting practices. Failure of these subsidiaries to meet their applicable regulatory requirements could result in restrictions on any distributions of capital or retained earnings or stricter regulatory oversight of the subsidiaries. Our ability to pay dividends and make other forms of distributions may also be limited by repayment obligations and financial covenants in our outstanding loan facility agreements. Subsidiary Statutory Financial Information and Dividend Restrictions Our insurance and reinsurance subsidiaries prepare their statutory financial statements in accordance with statutory accounting practices prescribed or permitted by local regulators. Statutory accounting differs from U.S. GAAP, including in the treatment of investments, acquisition costs and deferred income taxes, amongst other items. The statutory capital and surplus amounts for the years ended December 31, 2016 and 2015 and statutory net income amounts for the years ended December 31, 2016 , 2015 and 2014 for our insurance and reinsurance subsidiaries based in Bermuda, the United Kingdom, Australia, the United States and Continental Europe were as follows: Statutory Capital and Surplus Required Actual Statutory Income 2016 2015 2016 2015 2016 2015 2014 Bermuda $ 622,183 $ 510,773 $ 2,131,308 $ 1,767,172 $ 339,548 $ 147,883 $ 41,750 U.K. $ 532,132 $ 61,819 $ 805,170 $ 629,208 $ 131,619 $ 113,296 $ 107,030 U.S. $ 209,283 $ 147,538 $ 662,942 $ 756,543 $ (1,439 ) $ 14,964 $ 91,576 Europe $ 240,107 $ 44,126 $ 286,039 $ 211,458 $ 31,075 $ 1,856 $ 11,959 As at December 31, 2016 , the total amount of net assets of our consolidated subsidiaries that were restricted was $1.6 billion . Certain material aspects of these laws and regulations as they relate to solvency, dividends and capital and surplus are summarized below. Bermuda Our Bermuda-based insurance and reinsurance subsidiaries are registered under the Insurance Act 1978 of Bermuda and related regulations, as amended (the "Insurance Act"). The Insurance Act imposes certain solvency and liquidity standards and auditing and reporting requirements and grants the BMA powers to supervise, investigate, require information and the production of documents and intervene in the affairs of insurance companies. The Insurance Act requires that our Bermuda-based insurance and reinsurance subsidiaries maintain certain solvency and liquidity standards. The minimum liquidity ratio requires that the value of relevant assets must not be less than 75% of the amount of relevant liabilities. The minimum solvency margin, which varies depending on the class of the insurer, is determined as a percentage of either net reserves for losses and LAE or premiums or pursuant to a risk-based capital measure. Our Bermuda subsidiaries with commercial insurance licenses are required to maintain a minimum statutory capital and surplus (Enhanced Capital Requirement or "ECR") at least equal to the greater of a minimum solvency margin or the Bermuda Solvency Capital Requirement ("BSCR"). The BSCR is calculated based on a standardized risk-based capital model. Each of our regulated Bermuda insurance and reinsurance subsidiaries would be prohibited from declaring or paying any dividends if it were in breach of its minimum solvency margin (which is a function of outstanding losses) or liquidity ratio (which is a function of relevant assets) or if the declaration or payment of such dividends would cause it to fail to meet such margin or ratio. In addition, each of our regulated Bermuda insurance and reinsurance subsidiaries is prohibited, without the prior approval of the BMA, from reducing by 15% or more its total statutory capital as set out in its previous year’s statutory financial statements. Our Bermuda insurance companies that are in run-off are required to seek regulatory approval for any dividends or distributions. As of December 31, 2016 and 2015 , each of our Bermuda-based insurance and reinsurance subsidiaries exceeded their respective minimum solvency and liquidity requirements. The Bermuda insurance and reinsurance subsidiaries in aggregate exceeded minimum solvency requirements by $1.5 billion as of December 31, 2016 ( 2015 : $1.26 billion ) and were in compliance with their liquidity requirements. United Kingdom U.K. Insurance Companies (non-Lloyd's) Our U.K. based insurance subsidiaries are regulated by the U.K. Prudential Regulatory Authority (the "PRA") and the Financial Conduct Authority (the "FCA", together with the PRA, the "U.K. Regulator"). Our U.K.-based insurance subsidiaries are required to maintain adequate financial resources in accordance with the requirements of the U.K. Regulator. The calculation of the minimum capital resources requirements in any particular case depends on, among other things, the type and amount of insurance business written and claims paid by the insurance company. As at December 31, 2016 and 2015 , all of our U.K. insurance subsidiaries maintained capital in excess of the minimum capital resources requirements and complied with the relevant U.K. Regulator requirements. The U.K.-based insurance subsidiaries, in aggregate, maintained capital in excess of the minimum capital resources requirements by $273.0 million and $567.4 million as of December 31, 2016 and 2015 , respectively. The Solvency II framework directive took effect on January 1, 2016. Solvency II sets out E.U.-wide requirements on capital adequacy and risk management for insurers with the aim of further increasing policyholder protection, instilling greater risk awareness and improving the international competitiveness of E.U. insurers. Insurers must comply with a Solvency Capital Requirement ("SCR"), which is calculated using either the Solvency II standard formula or a bespoke internal model. Our non-Lloyd's U.K. companies use the standard formula. The U.K. Regulator’s rules require our U.K. insurance subsidiaries to obtain regulatory approval for any proposed or actual payment of a dividend. From January 1, 2016, the U.K. Regulator has used the SCR, among other tests, when assessing requests to make distributions. Lloyd’s As of December 31, 2016 , we participated in the Lloyd’s market through our interests in: (i) Atrium’s Syndicate 609, which is managed by Atrium Underwriters Limited, a Lloyd's managing agent, and the Atrium corporate member; (ii) StarStone’s Syndicate 1301, which is managed by StarStone Underwriting Limited ("SUL"), a Lloyd’s managing agent, and the StarStone corporate member; and (iii) Syndicate 2008, a wholly aligned syndicate that has permission to underwrite RITC business and other run-off or discontinued business type transactions with other Lloyd’s syndicates, and its corporate member. During 2015, SUL assumed the role of managing agent for Syndicate 2008 in place of Shelbourne Syndicate Services Limited as we streamlined our organizational structure and combined Shelbourne and StarStone resources into one agency. For the 2017 underwriting year, participation in all three syndicates will be through a common corporate member. The underwriting capacity of a member of Lloyd’s is supported by providing Funds at Lloyd’s, as described in Note 5 - "Investments." Business plans, including maximum underwriting capacity, for Lloyd’s syndicates requires annual approval by the Lloyd’s Franchise Board, which may require changes to any business plan or additional capital to support underwriting plans. The Lloyd’s market has applied the Solvency II internal model under Lloyd’s supervision, and our Lloyd’s operations are required to meet Solvency II standards. Effective January 1, 2016, Lloyd's received approval from the PRA to use its internal model under the Solvency II regime. United States Our U.S. non-life run-off and active underwriting insurance and reinsurance subsidiaries are subject to the insurance laws and regulations of the states in which they are domiciled, licensed and/or eligible to conduct business. These laws restrict the amount of dividends the subsidiaries can pay to us. The restrictions are generally based on statutory net income and/or certain levels of statutory surplus as determined in accordance with the relevant statutory accounting requirements of the individual domiciliary states or states in which any of the insurance or reinsurance subsidiaries are domiciled. Generally, prior regulatory approval must be obtained before an insurer may pay a dividend or make a distribution above a specified level. For all of our U.S. insurance and reinsurance subsidiaries, with the exception of one subsidiary which has a permitted accounting practice to treat an adverse development cover reinsurance agreement as prospective reinsurance, there are no prescribed or permitted statutory accounting practices that differ significantly from the statutory accounting principles established by the National Association of Insurance Commissioners ("NAIC"). The U.S. insurance and reinsurance subsidiaries are also required to maintain minimum levels of solvency and liquidity as determined by law, and to comply with risk-based capital requirements and licensing rules. As of December 31, 2016 , all of our U.S. non-life insurance and reinsurance subsidiaries exceeded their required levels of risk-based capital. On an aggregate basis, our U.S. non-life insurance and reinsurance subsidiaries exceeded their minimum levels of risk-based capital as of December 31, 2016 by $402.0 million ( December 31, 2015 : $528.3 million ). Our life and annuities subsidiaries file financial statements with state insurance regulatory authorities and the NAIC in the United States and the Office of Superintendent of Financial Institutions ("OSFI") in Canada (as a result of one of our subsidiaries having a Canadian branch operation). Our life and annuity companies are subject to certain Risk-Based Capital ("RBC") requirements as specified by the NAIC and OSFI. RBC is used to evaluate the adequacy of capital and surplus maintained by our life and annuities companies in relation to risks associated with: (i) asset risk; (ii) insurance risk; (iii) interest rate risk and (iv) business risk. As of December 31, 2016 and 2015 , our life and annuities subsidiaries exceeded their minimum RBC requirements by $51.6 million ( 2015 : $80.8 million ). These subsidiaries are restricted by state laws and regulations as to the amount of dividends they may pay. Any dividends in excess of limits are deemed "extraordinary" and require approval. As of December 31, 2016 and 2015 , the maximum dividend payout which may be made without prior approval is $ nil ( 2015 : $0.5 million ). Europe Our Swiss insurance subsidiary, Harper Insurance Limited, is regulated by the Swiss Financial Market Supervisory Authority ("FINMA") pursuant to the Insurance Supervisory Act 2004. This subsidiary is obligated to maintain a minimum solvency margin based on the Solvency I and Swiss Solvency Test regulations ("SST") as stipulated by the Insurance Supervisory Act. From January 1, 2016, Switzerland has been granted full Solvency II equivalence by the European Commission. As of December 31, 2016 and 2015 , this subsidiary exceeded the SST requirements by $6.1 million ( 2015 : $94.8 million ). The amount of dividends that this subsidiary is permitted to distribute is restricted to freely distributable reserves, which consist of retained earnings, the current year profit and legal reserves. Any dividend exceeding the current year profit requires FINMA’s approval. The solvency and capital requirements must continue to be met following any distribution. Our Liechtenstein insurance subsidiary (StarStone Insurance Europe AG) is regulated by the Liechtenstein Financial Market Authority ("FMA") pursuant to the Liechtenstein Insurance Supervisory Act. This subsidiary is obligated to maintain a minimum solvency margin based on the Solvency I regulations. As of December 31, 2016 , this subsidiary exceeded the Solvency I requirements by $12.8 million ( 2015 : $20.4 million ). The amount of dividends that this subsidiary is permitted to distribute is restricted to freely distributable reserves, which consist of retained earnings, the current year profit and legal reserves. Any dividend exceeding the current year profit requires the FMA’s approval. Solvency and capital requirements for this subsidiary are based on the Solvency II framework and must continue to be met following any distribution. Our Irish and Belgian life insurance subsidiaries file financial statements and returns with the Central Bank of Ireland and the National Bank of Belgium, respectively. These subsidiaries were in compliance with their solvency and capital requirements under Solvency II, and must continue to be met following any distribution.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	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. Cash, cash equivalents and fixed maturity investments are managed pursuant to guidelines that follow prudent standards of diversification and limit the allowable holdings of a single issue and issuers. Other investments are managed pursuant to guidelines that emphasize diversification and liquidity. Pursuant to these guidelines, we manage and monitor risk across a variety of investment funds and vehicles, markets and counterparties. We are also subject to custodial credit risk on our fixed maturity and equity 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 our insurance and reinsurance balances recoverable. 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. Amounts recoverable from reinsurers are described Note 10 - "Reinsurance Balances Recoverable." 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 balance is credited with investment income and losses payable are deducted. We are subject to credit risk if the reinsured company is unable to honor the value of the funds held balances, such as in the event of insolvency. However, we generally have the contractual ability to offset any shortfall in the payment of the funds held balances with amounts owed by us to the reinsured for losses payable and other amounts contractually due. We routinely monitor the creditworthiness of reinsured companies with whom we have funds held arrangements. We have a significant concentration of $1.0 billion to one reinsured company which has financial strength credit ratings of A+ from A.M. Best and AA from Standard & Poor's, as well as to KaylaRe as described in Note 21 - "Related Party Transactions". 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 counterparties noted above, exceeded 10% of shareholders’ equity as of December 31, 2016 . Operating Leases We lease office space under operating leases expiring in various years through 2026. The leases are renewable at our option under certain circumstances. The following is a schedule of future minimum rental payments on non-cancelable leases as of December 31, 2016 : 2017 $ 10,022 2018 9,510 2019 7,752 2020 6,183 2021 4,147 2022 and beyond 8,170 $ 45,784 Rent expense for the years ended December 31, 2016 , 2015 and 2014 was $9.7 million , $11.1 million and $10.2 million , respectively. 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 at December 31, 2016 , we had unfunded commitments to investment funds of $144.0 million . Guarantees As at December 31, 2016 and 2015 , parental guarantees supporting subsidiaries' insurance obligations were $625.7 million and $334.2 million , respectively. The increase relates to new transactions during 2016 as described in Note 3 - "Acquisitions" and Note 4 - "Significant New Business", and includes $122.0 million for letters of credit issued under a Funds at Lloyd's facility as described in Note 6 - "Investments." Significant New Business On January 11, 2017 we entered into a reinsurance agreement with QBE. On February 6, 2017, we entered into a reinsurance agreement with RSA. These agreements are described in Note 4 - "Significant New Business." Asbestos Personal Injury Liabilities We acquired Dana Companies, LLC ("Dana") on December 30, 2016, as described in Note 3 - "Acquisitions". Dana continues to process asbestos personal injury claims in the normal course of business and is separately managed. Other liabilities included $220.5 million for indemnity and defense costs for pending and future claims at December 31, 2016, determined using standard actuarial techniques for asbestos-related exposures. Other liabilities also included $2.3 million for environmental liabilities associated with Dana properties. Other assets included $133.0 million at December 31, 2016 for estimated insurance recoveries relating to these liabilities. The recorded asset represents our assessment of the capacity of the insurance agreements to provide for the payment of anticipated defense and indemnity costs for pending claims and projected future demands. 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 indemnity and defense costs were paid in full. Redeemable Noncontrolling Interest We have the right to purchase the RNCI interests from the RNCI holders at certain times in the future (each such right, a "call right") and the RNCI holders have the right to sell their RNCI interests to us at certain times in the future (each such right, a "put right"). The RNCI rights held by Trident are described in Note 21 - "Related Party Transactions." Dowling has a right to participate if Trident exercises its put right.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION We monitor and report our results of operations in four segments: Non-life Run-off, Atrium, StarStone and Life and Annuities. These segments are described in Note 1 - "Description of Business." Atrium and StarStone, our active underwriting operations, are reported as separate segments because they are managed and operated in separate and distinct manners. Atrium’s senior management runs its day-to-day operations with limited involvement of our senior management, whereas our senior management and employees are involved in StarStone’s day-to-day operations. Atrium employees are not involved in the management or strategy of StarStone, nor are StarStone employees involved in the management or strategy of Atrium. Atrium and StarStone are monitored and reported upon separately and distinctly and their strategies and business plans are determined independently of each other. The presentation of the results in our Life and Annuities segment reflect the classification of Pavonia as discontinuing operations and held-for-sale. Following the sale of Pavonia, we will no longer have any annuity products and our continuing life business comprises term life products in Alpha and Laguna, and the life settlements business. The following tables set forth selected and consolidated statement of earnings results by segment for the years ended December 31, 2016 , 2015 , 2014 : 2016 Non-life Run-off Atrium StarStone Life and Annuities Eliminations Consolidated INCOME Net premiums earned $ 16,755 $ 124,416 $ 676,608 $ 5,735 $ — $ 823,514 Fees and commission income 25,324 18,189 5,102 — (9,251 ) 39,364 Net investment income 143,783 2,940 22,221 20,043 (3,524 ) 185,463 Net realized and unrealized gains (losses) 77,689 (601 ) 5,728 (4,998 ) — 77,818 Other income 4,003 206 1,780 353 (1,506 ) 4,836 267,554 145,150 711,439 21,133 (14,281 ) 1,130,995 EXPENSES Net incurred losses and LAE (285,881 ) 58,387 401,593 — — 174,099 Life and annuity policy benefits — — — (2,038 ) — (2,038 ) Acquisition costs 4,198 44,670 138,822 612 (1,733 ) 186,569 General and administrative expenses 275,199 25,132 125,279 7,148 (9,024 ) 423,734 Interest expense 22,863 198 47 1,058 (3,524 ) 20,642 Net foreign exchange losses (gains) (1,678 ) 3,310 (754 ) (213 ) — 665 14,701 131,697 664,987 6,567 (14,281 ) 803,671 EARNINGS BEFORE INCOME TAXES 252,853 13,453 46,452 14,566 — 327,324 INCOME TAXES (28,577 ) (2,573 ) (3,693 ) (31 ) — (34,874 ) NET EARNINGS FROM CONTINUING OPERATIONS 224,276 10,880 42,759 14,535 — 292,450 NET EARNINGS FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE — — — 11,963 — 11,963 Less: Net earnings attributable to noncontrolling interest (17,600 ) (4,464 ) (17,542 ) — — (39,606 ) NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED $ 206,676 $ 6,416 $ 25,217 $ 26,498 $ — $ 264,807 2015 Non-life Run-off Atrium StarStone Life and Annuities Eliminations Consolidated INCOME Net premiums earned $ 44,369 $ 134,675 $ 573,146 $ 1,554 $ — $ 753,744 Fees and commission income 21,366 28,352 — — (10,371 ) 39,347 Net investment income 84,185 2,225 15,937 21,137 (920 ) 122,564 Net realized and unrealized gains (losses) (31,193 ) 252 (9,784 ) (798 ) — (41,523 ) Other income 29,293 359 676 — — 30,328 148,020 165,863 579,975 21,893 (11,291 ) 904,460 EXPENSES Net incurred losses and LAE (270,830 ) 47,479 327,684 — — 104,333 Life and annuity policy benefits — — — (546 ) — (546 ) Acquisition costs 8,860 45,509 109,347 — — 163,716 General and administrative expenses 238,989 31,610 126,132 2,799 (10,371 ) 389,159 Interest expense 14,565 4,264 6 1,488 (920 ) 19,403 Net foreign exchange losses (gains) 4,372 213 (480 ) (732 ) — 3,373 (4,044 ) 129,075 562,689 3,009 (11,291 ) 679,438 EARNINGS BEFORE INCOME TAXES 152,064 36,788 17,286 18,884 — 225,022 INCOME TAXES (12,570 ) (5,968 ) 5,888 — — (12,650 ) NET EARNINGS FROM CONTINUING OPERATIONS 139,494 30,820 23,174 18,884 — 212,372 NET LOSS FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE — — — (2,031 ) — (2,031 ) Less: Net losses (earnings) attributable to noncontrolling interest 33,722 (14,262 ) (9,510 ) — — 9,950 NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED $ 173,216 $ 16,558 $ 13,664 $ 16,853 $ — $ 220,291 2014 Non-life Atrium StarStone Life and Eliminations Consolidated INCOME Net premiums earned $ 31,168 $ 135,945 $ 373,633 $ 2,245 $ — $ 542,991 Fees and commission income 19,342 26,176 — 32 (10,631 ) 34,919 Net investment income 57,899 1,748 5,321 1,056 — 66,024 Net realized and unrealized gains 48,030 41 2,136 1,784 — 51,991 Other income 13,310 223 616 — — 14,149 169,749 164,133 381,706 5,117 (10,631 ) 710,074 EXPENSES Net incurred losses and LAE (264,711 ) 55,428 218,429 — — 9,146 Life and annuity policy benefits — — — 84 — 84 Acquisition costs 8,393 43,417 65,734 (2 ) — 117,542 General and administrative expenses 198,063 34,921 113,344 1,423 (10,631 ) 337,120 Interest expense 7,493 5,429 — — — 12,922 Net foreign exchange losses (gains) 8,015 (1,559 ) 945 (1,439 ) — 5,962 (42,747 ) 137,636 398,452 66 (10,631 ) 482,776 EARNINGS (LOSS) BEFORE INCOME TAXES 212,496 26,497 (16,746 ) 5,051 — 227,298 INCOME TAXES 622 (5,092 ) (1,130 ) (1 ) — (5,601 ) NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 213,118 21,405 (17,876 ) 5,050 — 221,697 NET EARNINGS FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE — — — 5,539 — 5,539 Less: Net losses (earnings) attributable to noncontrolling interest (9,836 ) (10,974 ) 7,323 — — (13,487 ) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR GROUP LIMITED $ 203,282 $ 10,431 $ (10,553 ) $ 10,589 $ — $ 213,749 Gross Premiums Written by Geographical Area The following table summarizes our gross premiums written for the year ended December 31, 2016 by each of our operating segments by geographic area. Geographic distribution in subsequent years is subject to variation based upon market conditions and business strategies. Non-life Run-off Atrium StarStone Life and Annuities Total Total % Total % Total % Total % Total % (In thousands of U.S. dollars, except percentages) United States $ 17,316 100.0 % $ 79,433 55.5 % $ 520,045 60.8 % $ — — % $ 616,794 60.3 % United Kingdom — — % 9,200 6.4 % 98,067 11.5 % 899 12.6 % 108,166 10.6 % Europe — — % 8,797 6.1 % 135,971 15.9 % 6,256 87.4 % 151,024 14.8 % Asia — — % 6,766 4.7 % 43,200 5.1 % — — % 49,966 4.9 % Rest of World — — % 38,974 27.3 % 57,416 6.7 % — — % 96,390 9.4 % Total $ 17,316 100.0 % $ 143,170 100.0 % $ 854,699 100.0 % $ 7,155 100.0 % $ 1,022,340 100.0 % Assets by Segment Invested assets are managed on a subsidiary by subsidiary basis, and investment income and realized and unrealized gains on investments are recognized in each segment as earned. Our total assets as at December 31, 2016 and 2015 by segment were as follows (the elimination items include the elimination of intersegment assets): 2016 2015 Total assets: Non-life Run-off $ 8,297,103 $ 7,602,594 Atrium 563,754 559,377 StarStone 2,968,316 2,780,462 Life and annuities 1,644,013 1,695,994 Less: Eliminations (607,442 ) (865,893 ) $ 12,865,744 $ 11,772,534

Unaudited Condensed Quarterly F

Unaudited Condensed Quarterly Financial Data	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Unaudited Condensed Quarterly Financial Data	UNAUDITED CONDENSED QUARTERLY FINANCIAL DATA December 31, September 30, June 30, March 31, 2016 2015 2016 2015 2016 2015 2016 2015 INCOME Net premiums earned $ 216,188 $ 178,009 $ 205,730 $ 209,971 $ 208,709 $ 189,344 $ 192,887 $ 176,420 Fees and commission income 13,266 7,450 9,187 9,708 10,487 10,125 6,424 12,064 Net investment income 42,229 44,265 48,022 31,640 44,932 25,265 50,280 21,394 Net realized and unrealized gains (losses) (61,570 ) (56,705 ) 66,608 (15,835 ) 34,503 (8,296 ) 38,277 39,313 Other income (1,277 ) 12,648 414 2,370 3,289 11,833 2,410 3,477 208,836 185,667 329,961 237,854 301,920 228,271 290,278 252,668 EXPENSES Net incurred losses and loss adjustment expenses 1,321 (64,062 ) (6,902 ) 32,359 96,462 65,900 83,218 70,136 Life and annuity policy benefits (2,265 ) (1,808 ) 1,682 401 (1,613 ) 407 158 454 Acquisition costs 47,619 53,666 50,074 44,445 43,847 33,781 45,029 31,824 General and administrative expenses 123,497 106,754 103,097 96,818 104,206 90,837 92,934 94,750 Interest expense 4,796 5,368 5,027 5,156 5,421 4,876 5,398 4,003 Net foreign exchange losses (gains) (1,527 ) 7,004 2,276 (841 ) (1,856 ) 2,297 1,772 (5,087 ) 173,441 106,922 155,254 178,338 246,467 198,098 228,509 196,080 EARNINGS BEFORE INCOME TAXES 35,395 78,745 174,707 59,516 55,453 30,173 61,769 56,588 INCOME TAXES (11,228 ) 15,794 (8,227 ) (12,684 ) (8,050 ) (8,087 ) (7,369 ) (7,673 ) NET EARNINGS FROM CONTINUING OPERATIONS 24,167 94,539 166,480 46,832 47,403 22,086 54,400 48,915 NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE 5,483 (1,898 ) 3,897 (831 ) 2,378 (3,879 ) 205 4,577 NET EARNINGS 29,650 92,641 170,377 46,001 49,781 18,207 54,605 53,492 Less: Net losses (earnings) attributable to noncontrolling interest (7,005 ) 19,216 (14,329 ) 3,041 (9,187 ) (3,662 ) (9,085 ) (8,645 ) NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED $ 22,645 $ 111,857 $ 156,048 $ 49,042 $ 40,594 $ 14,545 $ 45,520 $ 44,847 EARNINGS PER SHARE —BASIC: Net earnings from continuing operations $ 0.91 $ 5.91 $ 7.86 $ 2.57 $ 1.99 $ 0.99 $ 2.34 $ 2.04 Net earnings (loss) from discontinuing operations $ 0.26 $ (0.11 ) $ 0.23 $ (0.02 ) $ 0.11 $ (0.23 ) $ 0.02 $ 0.29 Net earnings per ordinary share attributable to Enstar Group Limited shareholders $ 1.17 $ 5.80 $ 8.09 $ 2.55 $ 2.10 $ 0.76 $ 2.36 $ 2.33 EARNINGS PER SHARE — DILUTED: Net earnings from continuing operations $ 0.90 $ 5.86 $ 7.79 $ 2.55 $ 1.98 $ 0.98 $ 2.33 $ 2.03 Net earnings (loss) from discontinuing operations $ 0.26 $ (0.11 ) $ 0.23 $ (0.02 ) $ 0.11 $ (0.23 ) $ 0.02 $ 0.29 Net earnings per ordinary share attributable to Enstar Group Limited shareholders $ 1.16 $ 5.75 $ 8.02 $ 2.53 $ 2.09 $ 0.75 $ 2.35 $ 2.32

Schedule I - Summary of Investm

Schedule I - Summary of Investments Other Than Investments in Related Parties	12 Months Ended
	Dec. 31, 2016
Summary of Investments, Other than Investments in Related Parties [Abstract]
Schedule I - Summary of Investments Other Than Investments in Related Parties	SCHEDULE I ENSTAR GROUP LIMITED SUMMARY OF INVESTMENTS OTHER THAN INVESTMENTS IN RELATED PARTIES As of December 31, 2016 (Expressed in thousands of U.S. Dollars) Type of investment Cost (1) Fair Value Amount at which shown in the balance sheet (4) Fixed maturity securities and short-term investments — Trading: U.S. government and agency $ 844,746 $ 840,274 $ 840,274 Non-U.S. government 275,900 267,363 267,363 Corporate 2,402,062 2,387,322 2,387,322 Municipal 47,615 47,181 47,181 Residential mortgage-backed 378,516 373,528 373,528 Commercial mortgage-backed 220,727 217,212 217,212 Asset-backed 476,595 478,280 478,280 Total 4,646,161 4,611,160 4,611,160 Fixed maturity securities and short-term investments — Available-for-sale U.S. government and agency 12,784 12,710 12,710 Non-U.S. government 86,897 85,423 85,423 Corporate 159,243 158,655 158,655 Municipal 6,585 6,576 6,576 Residential mortgage-backed 488 527 527 Asset-backed 3,867 3,876 3,876 Total 269,864 267,767 267,767 Equities (2) 67,516 74,149 74,149 Other investments, at fair value (3) 590,048 590,048 590,048 Other investments, at cost 131,651 129,474 131,651 Total $ 5,705,240 $ 5,672,598 $ 5,674,775 (1) Original cost of fixed maturity securities is reduced by repayments and adjusted for amortization of premiums or accretion of discounts. (2) The difference in the amount of equities shown at fair value and the equities shown in our consolidated balance sheet relates to the fair value of $20.9 million as of December 31, 2016 for our investment in a registered investment company affiliated with entities owned by Trident. Refer to Note 21 of the notes to the consolidated financial statements. (3) The difference in the amount of other investments shown at fair value and the other investments shown in our consolidated balance sheet relates to the fair value of $347.0 million as of December 31, 2016 for our other investments in funds or companies owned by or affiliated with certain related parties. Refer to Note 21 of the notes to the consolidated financial statements. (4) The table above excludes businesses held for sale. Refer to Note 5 of the notes to the consolidated financial statements.

Schedule II - Condensed Financi

Schedule II - Condensed Financial Statements	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule II - Condensed Financial Statements	SCHEDULE II ENSTAR GROUP LIMITED CONDENSED FINANCIAL INFORMATION OF REGISTRANT Balance Sheets - Parent Company Only As of December 31, 2016 and 2015 2016 2015 (in thousands of U.S. dollars, except share data) ASSETS Cash and cash equivalents $ 4,884 $ 4,552 Balances due from subsidiaries 35,563 489,873 Investments in subsidiaries 3,400,401 2,674,084 Other assets 8,533 7,812 TOTAL ASSETS $ 3,449,381 $ 3,176,321 LIABILITIES Loans payable $ 488,103 $ 485,750 Balances due to subsidiaries 153,843 160,854 Other liabilities 5,123 12,845 TOTAL LIABILITIES 647,069 659,449 COMMITMENTS AND CONTINGENCIES SHAREHOLDERS’ EQUITY Share capital authorized, issued and fully paid, par value $1 each (authorized 2016 and 2015: 156,000,000): Ordinary shares (issued and outstanding 2016: 16,175,250; 2015: 16,133,334) 16,175 16,133 Non-voting convertible ordinary shares: Series A (issued 2016: nil; 2015: 2,972,892) — 2,973 Series C (issued and outstanding 2016: 2,792,157; 2015: 2,725,637) 2,792 2,726 Series E (issued and outstanding 2016: 404,771; 2015: 404,771) 405 405 Series C Preferred Shares (issued and outstanding 2016: 388,571; 2015: nil) 389 — Treasury shares at cost (Preferred shares 2016: 388,571; Series A non-voting convertible ordinary shares 2015: 2,972,892) (421,559 ) (421,559 ) Additional paid-in capital 1,380,109 1,373,044 Accumulated other comprehensive loss (23,549 ) (35,162 ) Retained earnings 1,847,550 1,578,312 Total Enstar Group Limited Shareholders’ Equity 2,802,312 2,516,872 TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY $ 3,449,381 $ 3,176,321 See accompanying notes to the Condensed Financial Information of Registrant SCHEDULE II ENSTAR GROUP LIMITED CONDENSED FINANCIAL INFORMATION OF REGISTRANT - CONTINUED Statements of Earnings - Parent Company Only For the Years Ended December 31, 2016 , 2015 and 2014 2016 2015 2014 (in thousands of U.S. dollars) INCOME Net investment income $ 44 $ 14,965 $ 11,865 Dividend income from subsidiaries 361,675 1,000 21,952 361,719 15,965 33,817 EXPENSES General and administrative expenses 59,755 50,349 43,241 Interest expense 10,109 8,693 8,201 Net foreign exchange (gains) losses (318 ) 213 379 69,546 59,255 51,821 EARNINGS (LOSS) BEFORE EQUITY IN UNDISTRIBUTED EARNINGS OF SUBSIDIARIES 292,173 (43,290 ) (18,004 ) EQUITY IN UNDISTRIBUTED EARNINGS OF SUBSIDIARIES - CONTINUING OPERATIONS (39,329 ) 265,612 226,214 EQUITY IN UNDISTRIBUTED EARNINGS OF SUBSIDIARIES - DISCONTINUING OPERATIONS 11,963 (2,031 ) 5,539 NET EARNINGS $ 264,807 $ 220,291 $ 213,749 Statements of Comprehensive Income - Parent Company Only For the Years Ended December 31, 2016 , 2015 and 2014 2016 2015 2014 (in thousands of U.S. dollars) NET EARNINGS $ 264,807 $ 220,291 $ 213,749 OTHER COMPREHENSIVE INCOME (LOSS) RELATING TO SUBSIDIARIES, NET OF TAX 11,613 (22,476 ) (26,664 ) COMPREHENSIVE INCOME $ 276,420 $ 197,815 $ 187,085 See accompanying notes to the Condensed Financial Information of Registrant SCHEDULE II ENSTAR GROUP LIMITED CONDENSED FINANCIAL INFORMATION OF REGISTRANT - CONTINUED Statements of Cash Flows - Parent Company Only For the Years Ended December 31, 2016 , 2015 and 2014 2016 2015 2014 (in thousands of U.S. dollars) OPERATING ACTIVITIES: Net cash flows provided by (used in) operating activities $ 39,185 $ (81,384 ) $ (88,970 ) INVESTING ACTIVITIES: Dividends and return of capital from subsidiaries 250,117 1,000 21,952 Contributions to subsidiaries (295,268 ) (218,935 ) (50 ) Net cash flows provided by (used in) investing activities (45,151 ) (217,935 ) 21,902 FINANCING ACTIVITIES: Repayment of loans (426,750 ) (223,500 ) (9,250 ) Receipt of loans 433,048 505,700 70,000 Net cash flows provided by financing activities 6,298 282,200 60,750 NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS 332 (17,119 ) (6,318 ) CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR 4,552 21,671 27,989 CASH AND CASH EQUIVALENTS, END OF YEAR $ 4,884 $ 4,552 $ 21,671 See accompanying notes to the Condensed Financial Information of Registrant Notes to the Condensed Financial Information of Registrant The Condensed Financial Information of Registrant should be read in conjunction with our consolidated financial statements and the accompanying notes thereto included in Part II - Item 8 of this Annual Report on Form 10-K. Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications had no impact on net earnings. Our wholly owned and majority owned subsidiaries are recorded based upon our proportionate share of our subsidiaries' net assets (similar to presenting them on the equity method). Investing activities in the Condensed Statements of Cash Flows primarily represents the flow of funds to and from subsidiaries to provide cash on hand to fund acquisitions and significant new business. Net investment income relates to interest on loans to subsidiaries. For the years ended December 31, 2016 , 2015 , and 2014 , interest paid was $ 15.0 million , $ 13.0 million , and $ 6.6 million , respectively. During the year ended December 31, 2016, non-cash investing activities included $111.6 million for dividends and return of capital from subsidiaries and $452.1 million for contributions to subsidiaries. These transactions were to settle intercompany balances, resulting in a net reduction in balances due from subsidiaries and an increase in investments in subsidiaries. There were no non-cash investing activities for the years ended December 31, 2015 and 2014. As at December 31, 2016 and 2015 , parental guarantees supporting subsidiaries' insurance obligations were $625.7 million and $334.2 million , respectively. As at December 31, 2016 and 2015 , retained earnings was $1,847.6 million and $1,578.3 million , an increase of $269.2 million . The increase in retained earnings was primarily attributable to net earnings of $264.8 million .

Schedule III - Supplementary In

Schedule III - Supplementary Insurance Information	12 Months Ended
	Dec. 31, 2016
Supplementary Insurance Information [Abstract]
Schedule III - Supplementary Insurance Information	SCHEDULE III ENSTAR GROUP LIMITED SUPPLEMENTARY INSURANCE INFORMATION (Expressed in thousands of U.S. Dollars) Deferred Acquisition Costs Reserves for Losses and Loss Adjustment Expenses Unearned Premiums Policy Benefits for Life and Annuity Contracts Net Premiums Earned Net Investment Income Losses and Loss Expenses and Policy Benefits Amortization of Deferred Acquisition Costs Other Operating Expenses Net Premiums Written 2016 Non-life run-off $ 1,081 $ 4,716,363 $ 15,107 $ — $ 16,755 $ 143,783 $ (285,881 ) $ 4,198 $ 296,384 $ 9,202 Atrium 16,964 212,122 61,862 — 124,416 2,940 58,386 44,670 28,641 140,437 StarStone 40,069 1,059,382 471,374 — 676,608 22,221 401,593 138,822 124,572 648,036 Life and annuities — — — 112,095 5,735 20,043 (2,038 ) 612 7,993 6,261 Eliminations — — — — — (3,524 ) — (1,733 ) (12,548 ) — Total $ 58,114 $ 5,987,867 $ 548,343 $ 112,095 $ 823,514 $ 185,463 $ 172,060 $ 186,569 $ 445,042 $ 803,936 2015 Non-life run-off $ 1,788 $ 4,585,454 $ 27,792 $ — $ 44,369 $ 84,185 $ (270,830 ) $ 8,860 $ 257,926 $ 22,594 Atrium 16,326 201,017 59,808 — 134,675 2,225 47,479 45,509 36,087 134,580 StarStone 71,009 933,678 455,171 — 573,146 15,937 327,684 109,347 125,658 628,427 Life and annuities — — — 126,321 1,554 21,137 (546 ) — 3,555 1,553 Eliminations — — — — — (920 ) — — (11,291 ) — Total $ 89,123 $ 5,720,149 $ 542,771 $ 126,321 $ 753,744 $ 122,564 $ 103,787 $ 163,716 $ 411,935 $ 787,154 2014 Non-life run-off $ — $ 3,435,010 $ 197 $ — $ 31,168 $ 57,899 $ (264,711 ) $ 8,393 $ 213,571 $ 10,272 Atrium 16,520 212,611 61,030 — 135,945 1,748 55,428 43,417 38,791 136,275 StarStone 45,186 861,800 406,706 — 373,633 5,321 218,429 65,734 114,289 399,174 Life and annuities — — — 8,940 2,245 1,056 84 15,029 (16 ) 2,235 Eliminations — — — — — — — — (10,631 ) — Total $ 61,706 $ 4,509,421 $ 467,933 $ 8,940 $ 542,991 $ 66,024 $ 9,230 $ 132,573 $ 356,004 $ 547,956

Schedule IV - Reinsurance

Schedule IV - Reinsurance	12 Months Ended
	Dec. 31, 2016
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]
Schedule IV - Reinsurance	SCHEDULE IV ENSTAR GROUP LIMITED REINSURANCE For the Years Ended December 31, 2016 , 2015 and 2014 (Expressed in thousands of U.S. Dollars) Gross Ceded to Other Companies Assumed from Other Companies Net Amount Percentage of Amount Assumed to Net 2016 Life insurance in force $ 2,317,567 $ (585,575 ) $ — $ 1,731,992 — % Premiums earned: Property and casualty 804,141 (178,834 ) 192,472 817,779 23.5 % Life and annuities 7,221 (1,486 ) — 5,735 — % Total premiums earned $ 811,362 $ (180,320 ) $ 192,472 $ 823,514 2015 Life insurance in force $ 2,978,466 $ (777,759 ) $ — $ 2,200,707 — % Premiums earned: Property and casualty 854,856 (283,489 ) 180,823 752,190 24.0 % Life and annuities 2,884 (1,330 ) — 1,554 — % Total premiums earned $ 857,740 $ (284,819 ) $ 180,823 $ 753,744 2014 Life insurance in force $ 901,639 $ (808,142 ) $ — $ 93,497 — % Premiums earned: Property and casualty 703,281 (217,383 ) 54,848 540,746 10.1 % Life and annuities 3,889 (1,644 ) — 2,245 — % Total premiums earned $ 707,170 $ (219,027 ) $ 54,848 $ 542,991

Schedule V - Valuation and Qual

Schedule V - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2016
Valuation and Qualifying Accounts [Abstract]
Schedule V - Valuation and Qualifying Accounts	SCHEDULE V ENSTAR GROUP LIMITED VALUATION AND QUALIFYING ACCOUNTS For the Years Ended December 31, 2016 , 2015 and 2014 (Expressed in thousands of U.S. Dollars) Balance at Beginning of Year Charged to costs and expenses Charged to other Deductions (2) Balance at End of Year December 31, 2016: Reinsurance balances recoverable: Provisions for bad debt 210,327 (13,822 ) (19,255 ) (2,734 ) 174,516 Valuation allowance for deferred tax assets 291,280 13,389 — (13,808 ) 290,861 December 31, 2015: Reinsurance balances recoverable: Provisions for bad debt 289,909 (25,271 ) (45,234 ) (9,077 ) 210,327 Valuation allowance for deferred tax assets 333,617 (17,379 ) — (24,958 ) 291,280 December 31, 2014: Reinsurance balances recoverable: Provisions for bad debt 338,614 (7,700 ) (28,665 ) (12,340 ) 289,909 Valuation allowance for deferred tax assets 255,126 (33,213 ) — 111,704 333,617 (1) These amounts are credited to net incurred losses and there is an offsetting debit within the same line, resulting in no impact on net earnings. (2) Credited to the related asset account.

Schedule VI - Supplementary Inf

Schedule VI - Supplementary Information Concerning Property/Casualty Insurance Operations	12 Months Ended
	Dec. 31, 2016
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Schedule VI - Supplementary Information Concerning Property/Casualty Insurance Operations	SCHEDULE VI ENSTAR GROUP LIMITED SUPPLEMENTARY INFORMATION CONCERNING PROPERTY/CASUALTY INSURANCE OPERATIONS As of and for the years ended December 31, 2016 , 2015 and 2014 (Expressed in thousands of U.S. Dollars) Affiliation with Registrant Deferred Acquisition Costs Reserves for Unpaid Losses and Loss Adjustment Expenses Unearned Premiums Net Premiums Earned Net Investment Income Net Losses and Loss Expenses Incurred Net Paid Losses and Loss Expenses Amortization of Deferred Acquisition Costs Net Premiums Written Current Year Prior Year Consolidated Subsidiaries 2016 $ 58,114 $ 5,987,867 $ 548,343 $ 817,779 $ 168,944 $ 493,016 $ (318,917 ) $ (833,057 ) $ 187,690 $ 797,675 2015 89,123 5,720,149 542,771 752,190 102,347 476,364 (372,031 ) (781,889 ) 163,716 785,601 2014 61,706 4,509,421 467,933 540,746 64,968 327,817 (318,671 ) (587,511 ) 117,544 545,721

Significant Accounting Polici39

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Preparation	The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP").
Basis of Consolidation	The consolidated financial statements include our assets, liabilities and results of operations as of December 31, 2016 and 2015 and for the years ended December 31, 2016 , 2015 and 2014 . Results of operations for acquired subsidiaries are included from the date of acquisition. All significant intercompany transactions and balances have been eliminated.
Reclassifications	Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications had no impact on net earnings.
Use of Estimates	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 could differ materially from our estimates. 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"); • liability for policy benefits for life and annuity contracts; • reinsurance balances recoverable; • gross and net premiums written and net premiums earned; • impairment charges, including other-than-temporary impairments on investment securities classified as available-for-sale, and impairments on goodwill, intangible assets and deferred charges; • fair value measurements of investments; • fair value estimates associated with accounting for acquisitions; and • redeemable noncontrolling interests.
Premiums	Non-Life Non-life premiums written are earned on a pro-rata basis over the period the coverage is provided. Reinsurance premiums are recorded at the inception of the policy, are based upon contractual terms and, for certain business, are estimated based on underlying contracts or from information provided by insureds and/or brokers. Changes in reinsurance premium estimates are expected and may result in adjustments in future periods. Any subsequent differences arising on such estimates are recorded as premiums written in the period in which they are determined. Certain non-life contracts are retrospectively rated and provide for a final adjustment to the premium based on the final settlement of all losses. Premiums on such contracts are adjusted based upon contractual terms, and management judgme nt is involved with respect to the estimate of the amount of losses that we expect to incur. Additional premiums are recognized at the time loss thresholds specified in the contract are exceeded and are earned over the coverage period, or are earned immediately if the period of risk coverage has passed. Life and Annuities Prior to going into run-off, our life and annuities subsidiaries wrote life insurance, including credit life and disability insurance, term life insurance, assumed life reinsurance and annuities. We will continue to recognize premiums on term life insurance, assumed life reinsurance and credit life and disability insurance. These premiums are generally recognized as revenue when due from policyholders. The policies include contracts with fixed and guaranteed premiums and benefits. Benefits and expenses are matched with such revenue to result in the recognition of profit over the life of the contracts. Premiums receivable Premiums receivable represent amounts currently due and amounts not yet due on insurance and reinsurance policies. Premiums for insurance policies are generally due at inception. Premiums for reinsurance policies generally become due over the period of coverage based on the policy terms. We monitor the credit risk associated with premiums receivable, taking into consideration the impact of our contractual right to offset loss obligations or unearned premiums against premiums receivable. Amounts deemed uncollectible are charged to net earnings in the period they are determined. Changes in the estimates of premiums written will result in an adjustment to premiums receivable in the period they are determined. Unearned premiums and prepaid reinsurance premiums Unearned premiums represent the portion of premiums written that relate to the unexpired terms of policies in force. Premiums ceded are similarly pro-rated over the period the coverage is provided with the unearned portion being deferred as prepaid reinsurance premiums.
Acquisition Costs	Acquisition costs, consisting principally of commissions and brokerage expenses and certain premium taxes and fees incurred at the time a contract or policy is issued and that vary with and are directly related to the successful efforts of acquiring new insurance contracts or renewing existing insurance contracts, are deferred and amortized over the period in which the related premiums are earned. Deferred acquisition costs are limited to their estimated realizable value by line of business based on the related unearned premiums, anticipated claims and claim expenses and anticipated investment income.
Losses and LAE	Non-life Run-off The liability for losses and LAE in the Non-life Run-off segment includes an amount determined from reported claims and an amount, based on historical loss experience and industry statistics, for losses incurred but not reported ("IBNR") determined using a variety of actuarial methods. These estimates are continually reviewed and are necessarily subject to the impact of future changes in factors such as claim severity and frequency, changes in economic conditions including the impact of inflation, legal and judicial developments, and medical cost trends. While we believe that the amount is adequate, the ultimate liability may be in excess of, or less than, the amounts provided. Adjustments will be reflected as part of net increase or reduction in losses and LAE liabilities in the periods in which they become known. Premium and commission adjustments may be triggered by incurred losses, and any amounts are recorded in the same period that the related incurred loss is recognized. Commutations of acquired companies’ exposures have the effect of accelerating the payout of claims compared to the probability-weighted ranges of actuarially projected cash flows that we apply when estimating the fair values of assets and liabilities at the time of acquisition. Any material acceleration of payout together with the impact of any material loss reserve savings in any period will also accelerate the amortization of fair value adjustments in that period. Gains or losses on settlement of losses and LAE liabilities by way of commutation or policy buy-back are recognized upon execution of a commutation or policy buyback with the insured or reinsured. Our insurance and reinsurance subsidiaries also establish provisions for LAE relating to run-off costs for the estimated duration of the run-off, which are included in losses and LAE. These provisions are assessed at each reporting date, and provisions relating to future periods are adjusted to reflect any changes in estimates of the periodic run-off costs or the duration of the run-off, including the impact of any acceleration of the run-off period that may be caused by commutations. Provisions relating to the current period together with any adjustment to future run-off provisions are included in net incurred losses and LAE in the consolidated statements of earnings. Atrium and StarStone The reserves for losses and LAE in the Atrium and StarStone segments include reserves for unpaid reported losses and for IBNR loss reserves. The reserves for unpaid reported losses and loss expenses are established by management based on reports from brokers, ceding companies and insureds and represent the estimated ultimate cost of events or conditions that have been reported to or specifically identified by us. The reserve for IBNR losses is established by us based on actuarially determined estimates of ultimate losses and loss expenses. Inherent in the estimate of ultimate losses and loss expenses are expected trends in claim severity and frequency and other factors which may vary significantly as claims are settled. Accordingly, ultimate losses and loss expenses may differ from the amounts recorded in the consolidated financial statements. These estimates are reviewed regularly and, as experience develops and new information becomes known, the reserves are adjusted as necessary. Such adjustments, if any, will be recorded in earnings in the period in which they become known. Prior period development arises from changes to loss estimates recognized in the current year that relate to loss reserves established in prev ious calendar years.
Policy Benefits for Life and Annuity Contracts	Policy benefits for life and annuity contracts (“policy benefits”) are calculated using the net level premium method and are derived using locked-in assumptions. Policy benefits are established and maintained at a level that we estimate will, when taken together with future premium payments and investment income expected to be earn ed on associated premiums, be sufficient to support all future cash flow benefit obligations and third-party servicing obligations as they become payable. We review policy benefits regularly and perform loss recognition testing based upon cash flow projections. Since the development of the policy benefits is based upon projections of future cash flows, we are required to make assumptions for mortality, longevity and morbidity rates, lapse rates, expenses and investment income. The assumptions used to determine policy benefits are determined at the inception of the contracts, reviewed and adjusted at the point of acquisition, as required, and are locked-in throughout the life of the contract unless a premium deficiency develops. These locked-in assumptions are based on a best estimate view of experience at the time they are established and may include a provision for adverse deviation. Assumptions are established based upon a combination of historical and industry experience, when available, and management judgment. Actual results could differ from these estimates. Policy benefit liabilities are reviewed periodically to determine whether a premium deficiency exists. Management reviews emerging experience and updates best estimate assumptions where appropriate. If existing policy benefit reserves, reduced by unamortized acquisition costs, together with the present value of future gross premiums using current best estimate assumptions, are insufficient in covering the present value of future benefits, settlement, and maintenance costs using current best estimate assumptions, a premium deficiency is deemed to exist. To remediate, unamortized acquisition costs are reduced until the premium deficiency has been eliminated. If unamortized acquisition costs have been entirely written off and a premium deficiency still exists, locked-in assumptions are revised and a charge for policy benefits is recognized. Because of the many assumptions and estimates used in establishing policy benefits and the long-term nature of the contracts, the reserving process, while based on actua rial techniques, is inherently uncertain.
Reinsurance Recoverable	Under funds held arrangements, the reinsured company has retained funds that would otherwise have been remitted to our reinsurance subsidiaries. The funds balance is credited with investment income and losses payable are deducted. Funds held are shown under two categories on the consolidated balance sheets, where funds held upon which we receive the underlying portfolio economics are shown as "Funds held - directly managed", and funds held where we receive a fixed crediting rate are shown as "Funds held by reinsured companies". Funds held by reinsured companies are carried at cost. Funds held - directly managed, carried at fair value, represents the aggregate of funds held at cost and the value of an embedded derivative. The embedded derivative relates to our contractual right to receive the return on the underlying investment portfolio economics. The investment returns on both categories of funds held are recognized in net investment income and net realized and unrealized gains (losses). The revaluation of the embedded derivative is included in net unrealized gains (losses). Amounts billed to, and due from, reinsurers resulting from paid movements in the underlying business are calculated in accordance with the terms of the individual reinsurance contracts. Similarly, reinsurance balances recoverable related to our case reserves are calculated by applying the terms of any applicable reinsurance coverage to movements in the underlying case reserves. Our estimate of reinsurance balances recoverable related to IBNR reserves is recognized on a basis consistent with the underlying IBNR reserves. Our reinsurance balances recoverable are presented net of a provision for uncollectible amounts, reflecting the amount deemed not collectible due to credit quality, collection problems due to the location of the reinsurer, contractual disputes with reinsurers over individual contentious claims, contract language or coverage issues.
Investments	Short-term investments and fixed maturity investments Short-term investments comprise investments with a maturity greater than three months up to one year from the date of purchase. Fixed maturities comprise investments with a maturity of greater than one year from the date of purchase. Short-term and fixed maturity investments classified as trading are carried at fair value, with realized and unrealized holding gains and losses included in net earnings and reported as net realized and unrealized gains and losses. Short-term and fixed maturity investments classified as available-for-sale are carried at fair value, with unrealized gains and losses excluded from net earnings and reported as a separate component of accumulated other comprehensive income. Realized gains and losses on sales of investments classified as available-for-sale are recognized in the consolidated statements of earnings. The costs of short-term and fixed maturity investments are adjusted for amortization of premiums and accretion of discounts, recognized using the effective yield method and included in net investment income. For mortgage-backed and asset-backed investments, and any other holdings for which there is a prepayment risk, prepayment assumptions are evaluated and reviewed on a regular basis. Investment purchases and sales are recorded on a trade-date basis. Realized gains and losses on the sale of investments are based upon specific identification of the cost of investments. Other-Than-Temporary Impairments Fixed maturity investments classified as available-for-sale are reviewed quarterly to determine if they have sustained an impairment of value that is, based on our judgment, considered to be other than temporary. The process includes reviewing each fixed maturity investment that is below cost and: (1) determining if we have the intent to sell the fixed maturity investment; (2) determining if it is more likely than not that we will be required to sell the fixed maturity investment before its anticipated recovery; and (3) assessing whether a credit loss exists, that is, whether we expect that the present value of the cash flows expected to be collected from the fixed maturity investment is less than the amortized cost basis of the investment. In assessing whether it is more likely than not that we will be required to sell a fixed maturity investment before its anticipated recovery, we consider various factors including our future cash flow requirements, legal and regulatory requirements, the level of our cash, cash equivalents, short-term investments and fixed maturity investments available-for-sale in an unrealized gain position, and other relevant factors. In evaluating credit losses, we consider a variety of factors in the assessment of a fixed maturity investment including: (1) the time period during which there has been a significant decline below cost; (2) the extent of the decline below cost and par; (3) the potential for the investment to recover in value; (4) an analysis of the financial condition of the issuer; (5) the rating of the issuer; and (6) failure of the issuer of the investment to make scheduled interest or principal payments. If we conclude an investment is other-than-temporarily impaired ("OTTI"), then the difference between the fair value and the amortized cost of the investment is presented as an OTTI charge in the consolidated statements of earnings, with an offset for any non-credit related loss component of the OTTI charge to be recognized in other comprehensive income. Accordingly, only the credit loss component of the OTTI amount would have an impact on our earnings. Equities Equities are classified as trading and are carried at fair value with realized and unrealized holding gains and losses included in net earnings and reported as net realized and unrealized gains and losses. Other investments, at fair value Other investments include investments in limited partnerships and limited liability companies (collectively "private equities") and fixed income funds, hedge funds, equity funds, real estate debt funds and collateralized loan obligation ("CLO") equity funds that carry their investments at fair value, as well as direct investments in CLO equities. These other investments are stated at fair value, which ordinarily will be the most recently reported net asset value as advised by the fund manager or administrator. Many of our fund investments publish net asset values on a daily basis and provide daily liquidity; others report on a monthly basis. Private equities typically report quarterly. The change in fair value is included in net realized and unrealized gains and losses on investments and recognized in net earnings. Other investments, at cost Investments in life settlements are recorded as other investments, at cost, and are accounted for under the investment method whereby we recognize our initial investment in the life settlement contracts at the transaction price plus all initial direct external costs. Continuing costs to keep the policy in force, primarily life insurance premiums, increase the carrying amount of the investment. We recognize income on individual investments in life settlements when the insured dies, at an amount equal to the excess of the investment proceeds over the carrying amount of the investment at that time. The investments are subject to quarterly impairment review on a contract-by-contract basis. An investment in life settlements is considered impaired if the undiscounted cash flows resulting from the expected proceeds from the investment in life settlements are not sufficient to recover the current carrying amount for the investment in life settlements plus anticipated undiscounted future premiums and other capitalizable future costs, if any. Impaired contracts are written down to their estimated fair value, which is determined on a discounted cash flow basis using current market longevity assumptions and market yields, with any impairment charges included within net realized and unrealized gains (losses).
Cash and cash equivalents	Cash equivalents includes all highly liquid debt instruments purchased with an original maturity of three months or less.
Fees and Commission Income	Fees and commission income primarily includes profit commissions earned from managed Lloyd's syndicates, recorded on an accrual basis.
Foreign Exchange	Our reporting currency is the U.S. dollar. Assets and liabilities of entities whose functional currency is not the U.S. dollar are translated at period end exchange rates. Revenues and expenses of such foreign entities are translated at average exchange rates during the year. The effect of the currency translation adjustments for these foreign entities is included in accumulated other comprehensive income (loss). Other foreign currency assets and liabilities that are considered monetary items are translated at exchange rates in effect at the balance sheet date. Foreign currency revenues and expenses are translated at transaction date exchange rates. These exchange gains and losses are recognized in net earnings.
Share-based Compensation	We have primarily used three types of share-based compensation: restricted shares and restricted share units, cash-settled stock appreciation rights ("SARs") and shares issued under our employee share purchase plans. With the exception of SARs and the incentive plan awards issued to certain employees of Atrium, our share-based compensation awards qualify for equity classification. The fair value of the compensation cost is measured at the grant date and is expensed over the service period of the award. The SARs and the Atrium incentive plan awards are classified as liability awards. Liability classified awards are recorded at fair value within other liabilities in the consolidated balance sheet with changes in fair value relating to the vested portion of the award recorded within general and administrative expenses in the consolidated statements of earnings.
Derivative Instruments	We recognize all derivatives as either assets or liabilities in the consolidated balance sheets and carry them at the fair value of the instrument. We utilize derivative instruments in our foreign currency risk management strategy. Changes in fair value and realized gains or losses on derivative instruments are recognized in net earnings if we have not designated a hedge or the criteria for a designated hedge has not been met or is not effective, or in accumulated other comprehensive income (loss) if a designated hedge has been effective. Certain of our funds held contain embedded derivatives as described above.
Income Taxes	Certain of our subsidiaries and branches operate in jurisdictions where they are subject to taxation. Current and deferred income taxes are charged or credited to net income, or, in certain cases, to accumulated other comprehensive income, based upon enacted tax laws and rates applicable in the relevant jurisdiction in the period in which the tax becomes accruable or realizable. Deferred income taxes are provided for all temporary differences between the bases of assets and liabilities used in the financial statements and those used in the various jurisdictional tax returns. When our assessment indicates that it is more likely than not that all or some portion of deferred income tax assets will not be realized, a valuation allowance is recorded against the deferred tax assets. We recognize a tax benefit relating to uncertain tax positions only where the position is more likely than not to be sustained assuming examination by tax authorities. A liability is recognized for any tax benefit (along with any interest and penalty, if applicable) claimed in a tax return in excess of the amount allowed to be recognized in the financial statements under U.S. GAAP. Any changes in amounts recognized are recorded in the period in which they are determined.
Earnings Per Share	Basic earnings per share is based on the weighted average number of ordinary shares outstanding and excludes potentially dilutive securities such as restricted shares, restricted share units, warrants, options and convertible securities. Diluted earnings per share is based on the weighted average number of ordinary and ordinary share equivalents outstanding calculated using the treasury stock method for all potentially dilutive securities. When the effect of dilutive securities would be anti-dilutive, these securities are excluded from the calculation of diluted earnings per share.
Acquisitions	The purchase method is used to account for acquisitions. This method requires that we record the acquired assets and liabilities at their estimated fair value. The fair values of each of the acquired reinsurance assets and liabilities are derived from probability-weighted ranges of the associated projected cash flows, based on actuarially prepared information and management’s run-off strategy. Our run-off strategy, as well as that of other run-off market participants, is expected to be different from the seller's as generally sellers are not specialized in running off insurance and reinsurance liabilities whereas we and other market participants do specialize in such run-offs. The key assumptions used by us and, we believe, by other run-off market participants in the fair valuation of acquired companies are (i) the projected payout, timing and amount of claims liabilities; (ii) the related projected timing and amount of reinsurance collections; (iii) an appropriate discount rate, which is applied to determine the present value of the future cash flows; (iv) the estimated unallocated LAE to be incurred over the life of the run-off; (v) the impact of any accelerated run-off strategy; and (vi) an appropriate risk margin.
Acquisitions, Fair Value Adjustment	The difference between the original carrying value of reinsurance liabilities and reinsurance assets acquired at the date of acquisition and their fair value is recorded as an intangible asset or other liability, which we refer to as the fair value adjustment ("FVA"). The FVA is amortized over the estimated payout period of outstanding losses and loss expenses acquired. To the extent the actual payout experience after the acquisition is materially faster or slower than anticipated at the time of the acquisition, there is an adjustment to the estimated ultimate loss reserves, or there are changes in bad debt provisions or in estimates of future run-off costs following accelerated payouts, then the amortization of the FVA is adjusted to reflect such changes.
Goodwill	The difference between the fair value of net assets acquired and purchase price is recorded as a goodwill asset or as a gain on bargain purchase in the consolidated statements of earnings. Goodwill is established initially upon acquisition and assessed at least annually for impairment. If the goodwill asset is determined to be impaired it is written down in the period in which the determination is made.
Intangible Assets	Intangible assets represent the fair value adjustments related to unpaid losses and LAE, reinsurance balances recoverable and policy benefits for life and annuity contracts along with the intangible assets arising from the acquisitions of Atrium and StarStone. Definite-lived intangible assets are amortized over their useful lives. Amortization of intangible assets is recognized in the consolidated statement of earnings. Indefinite-lived intangible assets are not subject to amortization. The carrying values of intangible assets are reviewed for indicators of impairment at least annually. Impairment is recognized if the carrying values of the intangible assets are not recoverable from their undiscounted cash flows and are measured as the difference between the carrying value and the fair value.
Retroactive Reinsurance and Deferred Charges	Retroactive reinsurance policies provide indemnification of losses and LAE with respect to past loss events. In our Non-life Run-off segment we use the balance sheet accounting approach for assumed loss portfolio transfers, whereby at the inception of the contract there are no premiums or losses recorded in earnings. At the inception of a contract, a deferred charge asset is recorded for the excess, if any, of the estimated ultimate losses payable over the premiums received. Deferred charges, recorded in other 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 charges 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 charges and the amount of periodic amortization. Deferred charges 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. In our Non-life Run-off and StarStone segments we have ceded business to KaylaRe Ltd., an affiliated reinsurer, as described in Note 21 - "Related Party Transactions". The reinsurance ceded by StarStone to KaylaRe Ltd. during the year ended December 31, 2016 was mostly recognized as retroactive reinsurance, except for the unearned ceded premium as at December 31, 2016 which is recognized as prospective reinsurance. The reinsurance ceded by StarStone to KaylaRe Ltd. from January 1, 2017 will be recognized as prospective reinsurance.
Redeemable Noncontrolling Interest	In connection with the acquisitions of Arden, Atrium and StarStone, certain subsidiaries issued shares to noncontrolling interests. These shares provide certain redemption rights to the holders, which may be settled in our own shares or cash, at our option. Redeemable noncontrolling interest with redemption features that are not solely within our control are classified within temporary equity in the consolidated balance sheets and carried at the redemption value, which is fair value. Change in the fair value is recognized through retained earnings as if the balance sheet date were also the redemption date.
Internal-use Software	Direct internal and external costs to acquire or develop internal-use software have been capitalized. We only capitalize costs incurred after the preliminary project stage has been completed, and when management has authorized and committed to funding the project and it is probable that the project will be completed and the software will be used to perform the functions intended. Capitalized costs related to internal-use software are amortized on a straight-line basis over the estimated useful lives of the assets. These capitalized costs are also assessed for impairment when impairment indicators exist.
Held-for-sale Business and Discontinued Operations	We report a business as held-for-sale when management has approved the sale or received approval to sell the business and is committed to a formal plan, the business is available for immediate sale, the business is being actively marketed, the sale is anticipated to occur during the next 12 months and certain other specified criteria are met. A business classified as held for sale is recorded at the lower of its carrying amount or estimated fair value less costs of selling. If the carrying amount of the business exceeds its estimated fair value, a loss is recognized. Assets and liabilities related to the businesses classified as held-for-sale are separately reported in our Consolidated Balance Sheets beginning in the period in which the business is classified as held-for-sale. Refer to Note 5 for further information regarding our held-for-sale business. This business was also classified as discontinued operations whose results were aggregated and presented in one line in the consolidated statements of earnings.
New Accounting Standards Adopted and Recently Issued Accounting Pronouncements Not Yet Adopted	New Accounting Standards Adopted in 2016 Accounting Standards Update ("ASU") 2016-18, Statement of Cash Flows - Restricted Cash In November 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-18, which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. We have early adopted this guidance and applied it retrospectively to all periods presented on our consolidated financial statements. ASU 2016-17, Consolidation - Interests Held through Related Parties that are under Common Control In October 2016, the FASB issued ASU 2016-17, which amends the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (“VIE”) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. The adoption of this guidance did not have a material impact on our consolidated financial statements and disclosures. ASU 2015-16, Business Combinations, Simplifying the Accounting for Measurement-Period Adjustment In September 2015, the FASB issued ASU 2015-16, which eliminates the requirement for an acquirer to retrospectively adjust the financial statements for measurement-period adjustments that occur in periods after a business combination is consummated. Under the new guidance, an acquirer must recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The adoption of this guidance did not have a material impact on our consolidated financial statements and disclosures. ASU 2015-09, Disclosures about Short-Duration Contracts In May 2015, the FASB issued ASU 2015-09, which makes targeted improvements to disclosure requirements for insurance companies that issue short-duration contracts. The ASU requires enhanced disclosures, on an annual basis, related to the reserve for losses and loss expenses which include (1) net incurred and paid claims development information by accident year, (2) a reconciliation of incurred and paid claims development information to the aggregate carrying amount of the reserve for losses and LAE, (3) for each accident year presented of incurred claims development, information about claim frequency (unless impracticable), and the amounts of IBNR liabilities, including expected development on reported claims, included in the reserve for losses and LAE, (4) a description of, and any significant changes to the methods for determining both IBNR and expected development on reported claims, and (5) for each accident year presented of incurred claims development, quantitative information about claims frequency, as well as a description of methodologies used for determining claim frequency information. The ASU is effective for annual periods beginning after December 15, 2015. While the adoption of this guidance impacted our disclosures, it did not have an impact on our consolidated financial statements. ASU 2015-07, Disclosures for Investments in Certain Entities that Calculate Net Asset Value or its Equivalent In May 2015, the FASB issued ASU 2015-07, which eliminates the requirement to categorize investments in the fair value hierarchy if their fair value is measured at the net asset value ("NAV") per share (or its equivalent) using the practical expedient in the FASB’s fair value measurement guidance. Instead, an entity is required to include those investments as a reconciling line item so that the total fair value amount of investments in the disclosure is consistent with the amount on the balance sheet. In addition, the scope of current disclosure requirements for investments eligible to be measured at NAV is limited to investments for which the practical expedient is applied. While the adoption of this guidance impacted our disclosures, it did not have an impact on our consolidated financial statements. ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs In April 2015, the FASB issued ASU 2015-03, which changes the presentation of debt issuance costs in financial statements. Under the guidance, an entity would present such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs is reported as interest expense. The adoption of this guidance did not have an impact on our consolidated financial statements and disclosures. ASU 2015-02, Amendments to the Consolidation Analysis In February 2015, the FASB issued ASU 2015-02, which requires entities to evaluate whether they should consolidate certain legal entities. The new consolidation guidance changes the way entities evaluate whether (1) they should consolidate limited partnerships and similar entities; (2) fees paid to a decision maker or service provider are variable interests in a VIE, and (3) variable interests in a VIE held by related parties of a registrant require the registrant to consolidate the VIE. The new guidance also eliminates the VIE consolidation model based on majority exposure to variability that applied to certain investment companies and similar entities. The ASU also significantly changes how to evaluate voting rights for entities that are not similar to limited partnerships when determining whether the entity is a VIE, which may affect entities for which decision making rights are conveyed through a contractual arrangement. The adoption of this guidance did not have a material impact on our consolidated financial statements and disclosures. Recently Issued Accounting Pronouncements Not Yet Adopted ASU 2017-04, Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued ASU 2017-04, which simplifies the accounting for goodwill impairments by eliminating Step 2 from the goodwill impairment test. Instead, if the carrying amount of a reporting unit exceeds its fair value, an impairment loss shall be recognized in an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. The ASU is effective for any interim and annual impairment tests for periods beginning after December 15, 2019. Early adoption is permitted for any interim and annual impairment tests occurring after January 1, 2017. We intend to adopt this new guidance for our annual impairment tests occurring after January 1, 2017 and do not expect the adoption to have a material impact on our consolidated financial statements. ASU 2017-01, Clarifying the Definition of a Business In January 2017, the FASB issued ASU 2017-01 to clarify the definition of a business in Accounting Standards Codification (“ASC”) 805 Business Combinations with the intent of making the application of the guidance more consistent and cost-efficient. This clarification is expected to result in fewer acquired sets of assets and liabilities being identified as businesses. The adoption of this guidance is not expected to have a material impact on our consolidated financial statements. ASU 2016-16, Intra-Entity Transfers of Assets Other Than Inventory In October 2016, the FASB issued ASU 2016-16, which requires immediate recognition of the tax consequences of many intercompany asset transfers other than inventory. The ASU is effective for interim and annual reporting periods beginning after December 15, 2017, however early adoption is permitted. The adoption of this guidance is not expected to have a material impact on our consolidated financial statements and disclosures. ASU 2016-15, Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued ASU 2016-15, which amends the guidance on the classification of certain cash receipts and payments in the statement of cash flows. The ASU is effective for interim and annual reporting periods beginning after December 15, 2017, however early adoption is permitted. The adoption of this guidance is not expected to have a material impact on our consolidated financial statements and disclosures. ASU 2016-13, Financial Instruments - Credit Losses - Measurement of Credit Losses on Financial Instruments In June 2016, the FASB issued ASU 2016-13, which amends the guidance on impairment of financial instruments and significantly changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The ASU will replace the existing “incurred loss” approach, with an “expected loss” model for instruments measured at amortized cost and require entities to record allowances for available-for-sale debt securities rather than reduce the carrying amount under the existing other-than-temporary-impairment model. The ASU also simplifies the accounting model for purchased credit-impaired debt securities and loans. The ASU is effective for interim and annual reporting periods beginning after December 15, 2019. We expect to adopt the new guidance on January 1, 2020 and upon adoption the OTTI approach we currently use for our available for sale securities whereby any credit losses are presented as write-downs on individual securities will be replaced by an approach whereby any credit losses are instead presented as an allowance against each security. This revised approach records the full effect of reversals of any credit losses in current period earnings, compared to current U.S. GAAP which amortizes the reversal of credit losses over the lifetime of the security. The length of time an available for sale 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 an available for sale 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. The adoption of this guidance is not expected to have a material impact on our consolidated financial statements and disclosures. ASU 2016-09, Improvements to Employee Share-Based Payment Accounting In March 2016, the FASB issued ASU 2016-09, which simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. The ASU is effective for interim and annual reporting periods beginning after December 15, 2016. The adoption of this guidance is not expected to have a material impact on our consolidated financial statements and disclosures. ASU 2016-07, Simplifying the Transition to the Equity Method of Accounting In March 2016, the FASB issued ASU 2016-07, which simplifies the equity method of accounting by eliminating the requirement to retrospectively apply the equity method to an investment that subsequently qualifies for such accounting as a result of an increase in the level of ownership interest or degree of influence. Entities are therefore required to apply the guidance prospectively to increases in the level of ownership interest or degree of influence occurring after the ASU’s effective date. The ASU further requires that unrealized holding gains or losses in accumulated other comprehensive income related to an available-for-sale security that becomes eligible for the equity method be recognized in earnings as of the date on which the investment qualifies for the equity method. The ASU is effective for interim and annual reporting periods beginning after December 15, 2016, with early adoption permitted. The adoption of this guidance is not expected to have a material impact on our consolidated financial statements and disclosures. ASU 2016-02, Leases In February 2016, the FASB issued ASU 2016-02, which amends the guidance on the classification, measurement and disclosure of leases for both lessors and lessees. The ASU requires lessees to recognize a right-of-use asset and a lease liability on the balance sheet and to disclose qualitative and quantitative information about leasing arrangements. The ASU is effective for interim and annual reporting periods beginning after December 15, 2018. We expect to adopt the new standard on January 1, 2019 and will recognize and measure our leasing arrangements at the beginning of the earliest period presented using the modified retrospective approach permitted by the ASU. The modified retrospective approach includes a number of specific optional practical expedients which we intend to elect on adoption of the ASU, relating to, (1) the identification and classification of leases that commenced before the effective date, (2) initial direct costs for leases that commenced before the effective date, and (3) the ability to use hindsight in evaluating lessee options to extend or terminate a lease. The election of these practical expedients will allow us to in effect, continue to account for leases that commence before the effective date in accordance with the previous GAAP unless the lease is modified. The only exception would be that we will be required to recognize a right-of-use asset and a lease liability for all our existing operating leases at each reporting date based on the present value of the remaining minimum lease rental payments that we are disclosing under current U.S. GAAP. We are continuing to review all our operating lease arrangements to quantify the right-of-use asset and the offsetting lease liability to be recorded on our Consolidated Balance Sheet upon adoption of this guidance. ASU 2016-01, Recognition and Measurement of Financial Instruments In January 2016, the FASB issued ASU 2016-01, which amends the guidance on the classification and measurement of financial instruments. Although the ASU retains many of the current requirements, it significantly revises an entity’s accounting related to (1) the classification and measurement of investments in equity securities, and (2) the presentation of certain fair value changes for financial liabilities measured at fair value. The ASU also amends certain disclosure requirements associated with the fair value of financial instruments. The ASU is effective for interim and annual reporting periods beginning after December 15, 2017. The adoption of this guidance may have an impact, possibly material, on our consolidated financial statements at the date of adoption in relation to any financial liabilities for which we may elect the fair value option. ASU's 2014-09, 2016-08, 2016-10, 2016-12, Revenue from Contracts with Customers In May 2014, the FASB issued ASU 2014-09, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The ASU applies to all contracts with customers except those that are within the scope of other top ics in the FASB ASC including ASC 944, Insurance . However, while contracts within the scope of ASC 944 are excluded from the scope of the ASU, certain insurance-related contracts should be accounted for under the ASU, for example contracts under which service providers charge their customers fixed fees in exchange for an agreement to provide services for an uncertain future event. Certain of the ASU’s provisions also apply to transfers of non-financial assets and include guidance on recognition and measurement. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers - Principal versus Agent Considerations , which clarifies the implementation guidance for principal versus agent considerations in ASU 2014-09. In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers - Identifying Performance Obligations and Licensing , which amends the guidance in ASU 2014-09 related to identifying performance obligations and accounting for licenses of intellectual property. In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers - Narrow-Scope Improvements and Practical Expedients , which clarifies the following aspects in ASU 2014-09 - (1) collectability, (2) presentation of sales taxes and other similar taxes collected from customers, (3) noncash considerations, (4) contract modifications at transition, (5) completed contracts at transition, and (6) technical correction. We are required to adopt ASU 2016-08, ASU 2016-10 and ASU 2016-12 together with ASU 2014-09, which is effective for interim and annual reporting periods beginning after December 15, 2017. We expect to adopt this guidance on January 1, 2018. The two permitted transition methods under the new revenue standard are the full retrospective method, in which case the guidance would be applied to each prior reporting period presented, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial adoption . We expect to adopt the guidance using the modified retrospective method. While we are still in the process of completing our analysis of the impact this guidance will have on our consolidated financial statements and related disclosures, we do not expect the impact to be material, as the majority of our revenues are within the scope of other FASB topics, primarily ASC 944, Insurance .

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2016
Dana Companies
Business Acquisition [Line Items]
Purchase Price and Fair Value of Assets Acquired	The total consideration for the transaction was $88.5 million . Purchase price $ 88,500 Net assets acquired at fair value $ 88,500 Excess of purchase price over fair value of net assets acquired $ —
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed as of Date of Acquisition	The following table summarizes the fair values of the assets acquired and liabilities assumed at the acquisition date, recorded in our Non-life Run-off segment. Total ASSETS Short-term investments, trading, at fair value $ 22,747 Fixed maturities, trading, at fair value 61,389 Other investments, at fair value 46,589 Total investments 130,725 Cash and cash equivalents 58,430 Restricted cash and cash equivalents 1,692 Other assets - Insurance balances recoverable 133,032 Other assets 5,383 TOTAL ASSETS 329,262 LIABILITIES Other liabilities - Asbestos related 220,496 Other liabilities 20,266 TOTAL LIABILITIES 240,762 NET ASSETS ACQUIRED AT FAIR VALUE $ 88,500
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements
Business Acquisition [Line Items]
Pro Forma Condensed Combined Statement of Earnings	Enstar Group Unaudited 2014 Sussex Alpha Wilton Re Pro forma Enstar Total income $ 710,074 $ 267,939 $ 44,910 $ 17,378 $ (14,557 ) $ 1,025,744 Total expenses (482,838 ) (360,018 ) (52,103 ) (10,884 ) (3,026 ) (908,869 ) Total noncontrolling interest (13,487 ) — — — — (13,487 ) Net earnings (loss) $ 213,749 $ (92,079 ) $ (7,193 ) $ 6,494 $ (17,583 ) $ 103,388 The following unaudited pro forma condensed combined statement of earnings for the years ended December 31, 2015 and 2014 combines our historical consolidated statements of earnings with those of Sussex, Alpha and Wilton Re, giving effect to the business combinations and related transactions as if they had occurred on January 1, 2014 and 2015. For the year ended December 31, 2015, the operating results of Sussex, Alpha and Wilton Re have been included in the consolidated financial statements from each of their respective dates of acquisition. The unaudited pro forma financial information presented below is for informational purposes only and is not necessarily indicative of the results of operations that would have been achieved if the acquisitions of Sussex, Alpha and Wilton Re and related transactions had taken place at the beginning of each period presented, nor is it indicative of future results. Enstar Group Unaudited 2015 Sussex Alpha Wilton Re Pro forma Enstar Total income $ 904,460 $ 29,990 $ 31,884 $ 5,793 $ 9,494 $ 981,621 Total expenses (694,119 ) (39,860 ) (47,026 ) (3,628 ) 5,894 (778,739 ) Total noncontrolling interest 9,950 — — — — 9,950 Net earnings (loss) $ 220,291 $ (9,870 ) $ (15,142 ) $ 2,165 $ 15,388 $ 212,832
Summary of Pro Forma Adjustments to Pro Forma Condensed Statement of Earnings	Summary of the Pro Forma Adjustments to the Pro Forma Condensed Consolidated Statement of Earnings for the Twelve Months Ended December 31, 2014 (Unaudited): Income : (a) Adjustment to recognize amortization of fair value adjustments related to unearned premium (14,557 ) Expenses : (a) Adjustment to interest expense to reflect financing costs of the acquisition for the period (5,744 ) (b) Adjustment to recognize amortization of fair value adjustments related to acquired losses and LAE liabilities, deferred acquisition costs and reinsurance balances recoverable (5,417 ) (c) Adjustment to income taxes for pro forma adjustments 8,135 (3,026 ) Summary of the Pro Forma Adjustments to the Pro Forma Condensed Consolidated Statement of Earnings for the Twelve Months Ended December 31, 2015 (Unaudited): Income: (a) Reversal of amortization of fair value adjustments related to unearned premium included in Enstar Group results but reflected in 2014 pro formas 13,344 (b) Adjustment to recognize amortization of fair value adjustments related to unearned premium (3,850 ) 9,494 Expenses: (a) Adjustment to interest expense to reflect financing costs of the acquisition for the period (1,098 ) (b) Adjustment to recognize amortization of fair value adjustments related to acquired losses and LAE liabilities and reinsurance balances recoverable (451 ) (c) Reversal of amortization of fair value adjustments related to acquisition costs included in Enstar Group results but reflected in 2014 pro formas 16,173 (d) Adjustment to income taxes for pro forma adjustments (8,730 ) 5,894
Nationale Suisse Assurance S.A.
Business Acquisition [Line Items]
Purchase Price and Fair Value of Assets Acquired	The total consideration for the transaction was €32.8 million (or $35.2 million ). Purchase price $ 35,225 Net assets acquired at fair value $ 35,225 Excess of purchase price over fair value of net assets acquired $ —
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed as of Date of Acquisition	The following table summarizes the fair values of the assets acquired and liabilities assumed in the Alpha transaction at the acquisition date, allocated by segment. Life and Annuities Non-life Total ASSETS Short-term investments, trading, at fair value $ — $ 8,644 $ 8,644 Short-term investments, available-for-sale, at fair value 6,687 — 6,687 Fixed maturities, trading, at fair value — 31,350 31,350 Fixed maturities, available-for-sale, at fair value 96,656 — 96,656 Other investments, at fair value — 1,339 1,339 Total investments 103,343 41,333 144,676 Cash and cash equivalents 25,258 39,451 64,709 Reinsurance balances recoverable — reserves 302 4,041 4,343 Reinsurance balances recoverable — paids 1,320 10,831 12,151 Prepaid reinsurance premiums — 3,213 3,213 Other assets 2,298 3,097 5,395 TOTAL ASSETS 132,521 101,966 234,487 LIABILITIES Losses and LAE 117,188 56,021 173,209 Funds withheld — 473 473 Insurance and reinsurance balances payable 779 6,212 6,991 Unearned premium — 5,969 5,969 Other liabilities 2,875 9,745 12,620 TOTAL LIABILITIES 120,842 78,420 199,262 NET ASSETS ACQUIRED AT FAIR VALUE $ 11,679 $ 23,546 $ 35,225
Wilton Re
Business Acquisition [Line Items]
Purchase Price and Fair Value of Assets Acquired	Purchase price $ 173,058 Net assets acquired at fair value $ 173,058 Excess of purchase price over fair value of net assets acquired $ —
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed as of Date of Acquisition	The following table summarizes the fair values of the assets acquired and liabilities assumed at the acquisition date. ASSETS Other investments $ 142,182 Cash and cash equivalents 5,043 Other assets 26,376 TOTAL ASSETS $ 173,601 TOTAL LIABILITIES 543 NET ASSETS ACQUIRED AT FAIR VALUE $ 173,058
Sussex Insurance Company
Business Acquisition [Line Items]
Purchase Price and Fair Value of Assets Acquired	Purchase price $ 218,000 Net assets acquired at fair value $ 218,000 Excess of purchase price over fair value of net assets acquired $ —
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed as of Date of Acquisition	The following table summarizes the fair values of the assets acquired and liabilities assumed at the acquisition date. ASSETS Short-term investments, trading, at fair value $ 85,309 Fixed maturities, trading, at fair value 523,227 Equities, trading, at fair value 31,439 Total investments 639,975 Cash and cash equivalents 358,458 Restricted cash and cash equivalents 15,279 Accrued interest receivable 3,984 Premiums receivable 37,190 Reinsurance balances recoverable 483,816 Prepaid reinsurance premiums 28,751 Other assets 43,939 TOTAL ASSETS 1,611,392 LIABILITIES Losses and LAE 1,257,205 Insurance and reinsurance balances payable 3,030 Unearned premium 79,293 Funds withheld 42,090 Other liabilities 11,774 TOTAL LIABILITIES 1,393,392 NET ASSETS ACQUIRED AT FAIR VALUE $ 218,000
StarStone
Business Acquisition [Line Items]
Purchase Price and Fair Value of Assets Acquired	Purchase price $ 656,088 Net assets acquired at fair value $ 643,088 Excess of purchase price over fair value of net assets acquired $ 13,000
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed as of Date of Acquisition	The following table summarizes the fair values of the assets acquired and liabilities assumed in the StarStone transaction at the acquisition date, allocated by segment. StarStone Segment Non-life Run-off Segment Total ASSETS Short-term investments, trading, at fair value $ 73,425 $ 25,888 $ 99,313 Fixed maturities, trading, at fair value 736,765 329,235 1,066,000 Other investments 2,068 — 2,068 Total investments 812,258 355,123 1,167,381 Cash and cash equivalents 211,718 127,890 339,608 Restricted cash and cash equivalents 22,779 — 22,779 Premiums receivable 321,350 — 321,350 Reinsurance balances recoverable — reserves 210,742 152,057 362,799 Reinsurance balances recoverable — paids 21,122 20,100 41,222 Prepaid reinsurance premiums 144,221 25,221 169,442 Intangible assets 43,900 — 43,900 Other assets 37,621 — 37,621 TOTAL ASSETS 1,825,711 680,391 2,506,102 LIABILITIES Losses and LAE 675,424 588,822 1,264,246 Insurance and reinsurance balances payable 140,997 42,447 183,444 Unearned premium 343,840 49,122 392,962 Other liabilities 22,362 — 22,362 TOTAL LIABILITIES 1,182,623 680,391 1,863,014 NET ASSETS ACQUIRED AT FAIR VALUE 643,088 — 643,088 Goodwill 13,000 — 13,000 ACQUISITION DATE FAIR VALUE $ 656,088 $ — $ 656,088
Summary of Intangible Assets Recorded in Connection with Acquisition	The foll owing table summarizes the intangible assets recorded in connection with the acquisition: Amount Economic Useful Life Syndicate capacity $ 4,000 Indefinite U.S. insurance licenses 19,900 Indefinite Technology 15,000 4 Years Brand 5,000 6 Years Intangible assets as of the acquisition date $ 43,900
Pro Forma Condensed Combined Statement of Earnings	The following pro forma condensed combined statement of earnings for the years ended December 31, 2014 combines our historical consolidated statements of earnings with the historical consolidated statements of earnings of StarStone, giving effect to the business combinations and related transactions as if they had occurred on January 1, 2014. The unaudited pro forma financial information presented below is for informational purposes only and is not necessarily indicative of the results of operations that would have been achieved if the acquisition of StarStone and related transactions had taken place at the beginning of each period presented, nor is it indicative of future results. Enstar Group Limited Unaudited 2014 StarStone Proforma Adjustments Enstar Group Limited - Proforma Total income $ 710,074 $ 147,193 $ (1,846 ) $ 855,421 Total expenses (482,838 ) (145,479 ) 3,670 (624,647 ) Total noncontrolling interest (13,487 ) — (1,451 ) (14,938 ) Net earnings $ 213,749 $ 1,714 $ 373 $ 215,836
Summary of Pro Forma Adjustments to Pro Forma Condensed Statement of Earnings	Summary of the Pro Forma Adjustments to the Pro Forma Condensed Consolidated Statement of Earnings for the Twelve Months Ended December 31, 2014 (Unaudited): Income : (a) Adjustment to recognize amortization of fair value adjustments related to unearned premium (1,846 ) Expenses : (a) Adjustment to recognize amortization of definite-lived intangible assets (1,146 ) (b) Adjustment to recognize amortization of fair value adjustments related to acquired losses and loss adjustment expense liabilities and reinsurance balances recoverable 4,816 3,670 (c) Adjustment to noncontrolling interest for pro forma condensed consolidated statement of earnings (1,451 )

Held-For-Sale Business (Tables)

Held-For-Sale Business (Tables)	12 Months Ended
	Dec. 31, 2016
Discontinued Operations and Disposal Groups [Abstract]
Financial Information of Held-For-Sale Business	The following table summarizes the components of assets and liabilities held-for-sale on our consolidated balance sheet as at December 31, 2016 and 2015: December 31, December 31, Assets: Short-term investments, trading, at fair value $ — $ 2,246 Fixed maturities, trading, at fair value 326,382 262,273 Fixed maturities, held-to-maturity, at amortized cost 765,554 790,866 Equities, trading, at fair value 4,428 4,446 Other investments, at fair value 15,114 53,743 Cash and cash equivalents 18,018 26,680 Restricted cash and cash equivalents 5,202 11,415 Deferred tax assets 31,500 31,531 Reinsurance balances recoverable 18,029 22,083 Other assets 60,229 64,300 Total assets held for sale $ 1,244,456 $ 1,269,583 Liabilities: Policy benefits for life and annuity contracts $ 1,144,850 $ 1,178,376 Other liabilities 5,937 11,083 Total liabilities held for sale $ 1,150,787 $ 1,189,459 The following table summarizes the components of net earnings (losses) from discontinued operations on the consolidated statements of earnings for the years ended December 31, 2016, 2015 and 2014: December 31, December 31, December 31, INCOME Net premiums earned $ 69,089 $ 85,327 $ 103,459 Net investment income 38,140 35,404 36,599 Net realized and unrealized gains (losses) 4,263 271 10,628 Other income 1,912 7,690 1,813 $ 113,404 $ 128,692 $ 152,499 EXPENSES Life and annuity policy benefits 76,594 97,472 107,962 Acquisition costs 9,836 13,712 15,031 General and administrative expenses 14,416 13,886 17,206 Other expenses 199 486 1,220 $ 101,045 $ 125,556 $ 141,419 EARNINGS (LOSS) BEFORE INCOME TAXES 12,359 3,136 11,080 INCOME TAXES (396 ) $ (5,167 ) (5,541 ) NET EARNINGS FROM DISCONTINUED OPERATIONS $ 11,963 $ (2,031 ) $ 5,539 The following table presents the cash flows of Pavonia for the years ended December 31, 2016, 2015 and 2014: December 31, December 31, December 31, Operating activities $ (71,521 ) $ (5,893 ) $ (46,386 ) Investing activities 56,646 (24,766 ) 32,641 Financing Activities — — — Change in cash of businesses held for sale $ (14,875 ) $ (30,659 ) $ (13,745 )

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Estimated Fair Values of Investments in Fixed Maturity Investments, Short-Term Investments and Equities, Trading Securities	The fair values of our fixed maturity investments, short-term investments and equities classified as trading were as follows: December 31, December 31, U.S. government and agency $ 840,274 $ 742,918 Non-U.S. government 267,363 338,170 Corporate 2,387,322 2,564,618 Municipal 47,181 22,247 Residential mortgage-backed 373,528 381,573 Commercial mortgage-backed 217,212 232,847 Asset-backed 478,280 531,252 Total fixed maturity and short-term investments 4,611,160 4,813,625 Equities — U.S. 95,047 108,793 Equities — International — 2,702 $ 4,706,207 $ 4,925,120
Summary of Amortized Cost and Estimated Fair Value of Fixed Maturity and Short-term Investments by Contractual Maturity	The contractual maturities of our fixed maturity and short-term investments classified as available-for-sale 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 at December 31, 2016 Amortized Cost Fair Value % of Total Fair Value One year or less $ 48,561 $ 46,955 17.5 % More than one year through two years 62,855 61,395 22.9 % More than two years through five years 72,008 70,404 26.3 % More than five years through ten years 43,889 45,173 16.9 % More than ten years 38,196 39,437 14.7 % Residential mortgage-backed 488 527 0.2 % Asset-backed 3,867 3,876 1.5 % $ 269,864 $ 267,767 100.0 % The contractual maturities of our fixed maturity and short-term investments classified as trading 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 o r prepayment penalties. As at December 31, 2016 Amortized Cost Fair Value % of Total Fair Value One year or less $ 748,634 $ 739,820 16.0 % More than one year through two years 713,175 708,739 15.4 % More than two years through five years 1,270,909 1,259,564 27.3 % More than five years through ten years 651,539 648,156 14.1 % More than ten years 186,066 185,861 4.0 % Residential mortgage-backed 378,516 373,528 8.1 % Commercial mortgage-backed 220,727 217,212 4.7 % Asset-backed 476,595 478,280 10.4 % $ 4,646,161 $ 4,611,160 100.0 %
Amortized Cost and Estimated Fair Values of Company's Fixed Maturity and Short-Term Investments Classified as Available-for-Sale	The amortized cost and fair values of our fixed maturity and short-term investments classified as available-for-sale were as follows: As at December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Non-OTTI Fair Value U.S. government and agency $ 12,784 $ 32 $ (106 ) $ 12,710 Non-U.S. government 86,897 1,303 (2,777 ) 85,423 Corporate 159,243 2,040 (2,628 ) 158,655 Municipal 6,585 12 (21 ) 6,576 Residential mortgage-backed 488 39 — 527 Asset-backed 3,867 9 — 3,876 $ 269,864 $ 3,435 $ (5,532 ) $ 267,767 As at December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Non-OTTI Fair Value U.S. government and agency $ 25,102 $ 80 $ (341 ) $ 24,841 Non-U.S. government 89,631 42 (3,889 ) 85,784 Corporate 182,773 1,040 (3,429 ) 180,384 Municipal 5,959 4 (36 ) 5,927 Residential mortgage-backed 665 51 (1 ) 715 Asset-backed 4,660 — (10 ) 4,650 $ 308,790 $ 1,217 $ (7,706 ) $ 302,301
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 tables summarize our fixed maturity and short-term investments in a gross unrealized loss position: 12 Months or Greater Less Than 12 Months Total As at December 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturity and short-term investments, at fair value U.S. government and agency $ — $ — $ 10,743 $ (106 ) $ 10,743 $ (106 ) Non-U.S. government 8,316 (1,794 ) 30,086 (983 ) 38,402 (2,777 ) Corporate 8,003 (1,800 ) 42,304 (828 ) 50,307 (2,628 ) Municipal — — 3,132 (21 ) 3,132 (21 ) Total fixed maturity and short-term investments $ 16,319 $ (3,594 ) $ 86,265 $ (1,938 ) $ 102,584 $ (5,532 ) 12 Months or Greater Less Than 12 Months Total As at December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturity and short-term investments, at fair value U.S. government and agency $ 523 $ (2 ) $ 21,694 $ (339 ) $ 22,217 $ (341 ) Non-U.S. government 18,995 (2,633 ) 50,080 (1,256 ) 69,075 (3,889 ) Corporate 54,295 (2,394 ) 81,047 (1,035 ) 135,342 (3,429 ) Municipal — — 4,609 (36 ) 4,609 (36 ) Residential mortgage-backed 71 (1 ) — — 71 (1 ) Asset-backed 4,649 (10 ) — — 4,649 (10 ) Total fixed maturity and short-term investments $ 78,533 $ (5,040 ) $ 157,430 $ (2,666 ) $ 235,963 $ (7,706 )
Credit Ratings Company's Fixed Maturity and Short-Term Investments Available-for-Sale	The following table sets forth the credit ratings of our fixed maturity and short-term investments as of December 31, 2016 : Amortized Cost Fair Value % of Total Investments AAA Rated AA Rated A Rated BBB Rated Non- Investment Grade Not Rated U.S. government and agency $ 857,530 $ 852,984 17.5 % $ 846,698 $ 6,286 $ — $ — $ — $ — Non-U.S. government 362,797 352,786 7.2 % 140,357 150,569 43,771 18,089 — — Corporate 2,561,305 2,545,977 52.2 % 105,081 465,224 1,199,452 615,538 149,898 10,784 Municipal 54,200 53,757 1.1 % 25,566 25,834 2,357 — — — Residential mortgage-backed 379,004 374,055 7.7 % 370,067 403 3,487 — 97 1 Commercial mortgage-backed 220,727 217,212 4.4 % 100,065 41,542 41,837 16,383 77 17,308 Asset-backed 480,462 482,156 9.9 % 213,312 58,322 114,503 23,534 72,485 — Total $ 4,916,025 4,878,927 100.0 % 1,801,146 748,180 1,405,407 673,544 222,557 28,093 % of total fair value 36.9 % 15.3 % 28.8 % 13.8 % 4.6 % 0.6 %
Other Investments	The following table summarizes our other investments carried at fair value: December 31, December 31, Private equities and private equity funds $ 300,529 $ 232,372 Fixed income funds 249,023 280,749 Fixed income hedge funds 85,976 89,154 Equity funds 223,571 147,390 Multi-strategy hedge fund — 99,020 Real estate debt fund — 54,829 CLO equities 61,565 61,702 CLO equity funds 15,440 13,928 Other 943 1,145 $ 937,047 $ 980,289
Schedule of Life Settlement Contracts, Investment Method	The following table presents further information regarding our investments in life settlements as of December 31, 2016 and 2015 . December 31, 2016 December 31, 2015 Number of Contracts Carrying Face Value (Death Benefits) Number of Contracts Carrying Face Value (Death Benefits) Remaining Life Expectancy of Insureds: 0 – 1 year 2 $ 461 $ 700 2 $ 417 $ 700 1 – 2 years 7 11,396 18,337 4 3,032 5,000 2 – 3 years 11 15,338 29,715 19 24,072 39,123 3 – 4 years 17 17,013 32,189 14 9,695 20,932 4 – 5 years 16 10,377 23,302 16 9,025 22,457 Thereafter 181 77,066 431,034 221 86,830 491,499 Total 234 $ 131,651 $ 535,277 276 $ 133,071 $ 579,711
Realized Gain (Loss) on Investments	Components of net realized and unrealized gains (losses) for the years ended December 31, 2016 , 2015 and 2014 were as follows: 2016 2015 2014 Net realized gains (losses) on sale: Gross realized gains on fixed maturity securities, available-for-sale $ 405 $ 396 $ 196 Gross realized (losses) on fixed maturity securities, available-for-sale securities (21 ) (130 ) (138 ) Net realized investment gains (losses) on fixed maturity securities, trading 1,848 (4,291 ) 3,372 Net realized investment gains on equity securities, trading 5,348 19,884 18,738 Net realized investment losses on funds held - directly managed (14,616 ) — — Total net realized gains (losses) on sale (7,036 ) 15,859 22,168 Net unrealized gains (losses): Fixed maturity securities, trading 36,314 (52,918 ) 9,890 Equity securities, trading 6,561 (21,875 ) (8,665 ) Other investments 70,296 17,411 28,598 Change in fair value of embedded derivative on funds held – directly managed (28,317 ) — — Total net unrealized gains (losses) 84,854 (57,382 ) 29,823 Net realized and unrealized gains (losses) $ 77,818 $ (41,523 ) $ 51,991
Unrealized Gain (Loss) on Investments	Components of net realized and unrealized gains (losses) for the years ended December 31, 2016 , 2015 and 2014 were as follows: 2016 2015 2014 Net realized gains (losses) on sale: Gross realized gains on fixed maturity securities, available-for-sale $ 405 $ 396 $ 196 Gross realized (losses) on fixed maturity securities, available-for-sale securities (21 ) (130 ) (138 ) Net realized investment gains (losses) on fixed maturity securities, trading 1,848 (4,291 ) 3,372 Net realized investment gains on equity securities, trading 5,348 19,884 18,738 Net realized investment losses on funds held - directly managed (14,616 ) — — Total net realized gains (losses) on sale (7,036 ) 15,859 22,168 Net unrealized gains (losses): Fixed maturity securities, trading 36,314 (52,918 ) 9,890 Equity securities, trading 6,561 (21,875 ) (8,665 ) Other investments 70,296 17,411 28,598 Change in fair value of embedded derivative on funds held – directly managed (28,317 ) — — Total net unrealized gains (losses) 84,854 (57,382 ) 29,823 Net realized and unrealized gains (losses) $ 77,818 $ (41,523 ) $ 51,991
Major Categories of Net Investment Income	Major categories of net investment income for the years ended December 31, 2016 , 2015 and 2014 are summarized as follows: 2016 2015 2014 Fixed maturity investments $ 114,885 $ 87,512 $ 58,815 Short-term investments and cash and cash equivalents 4,491 5,993 6,209 Equity securities 4,874 5,580 5,671 Other investments 22,515 11,712 1,335 Funds held 22,583 234 1,376 Funds held – directly managed 5,769 — — Life settlements and other 18,191 20,871 593 Gross investment income 193,308 131,902 73,999 Investment expenses (7,845 ) (9,338 ) (7,975 ) Net investment income $ 185,463 $ 122,564 $ 66,024
Schedule of Carrying Value of Restricted Investments	The carrying value of our restricted assets, including restricted cash of $363.8 million and $499.9 million , as of December 31, 2016 and 2015 , respectively, was as follows: December 31, December 31, Collateral in trust for third party agreements $ 1,975,022 $ 1,993,065 Assets on deposit with regulatory authorities 882,400 906,973 Collateral for secured letter of credit facilities 177,263 212,544 Funds at Lloyd's (1) 220,328 382,624 $ 3,255,013 $ 3,495,206 (1) Our underwriting 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. In November 2016, we entered into an unsecured letter of credit agreement for Funds at Lloyd’s purposes ("FAL Facility") to issue up to $140.0 million of letters of credit, with a provision to increase the facility up to $200.0 million . The FAL Facility is available to satisfy our Funds at Lloyd’s requirements and replaces certain restricted assets and letter of credit arrangements. The FAL Facility expires in 2021. As at December 31, 2016 , our combined Funds at Lloyd's were comprised of cash and investments of $220.3 million and unsecured letters of credit of $122.0 million .

Funds Held - Directly Managed (

Funds Held - Directly Managed (Tables)	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Carrying Values of Assets and Liabilities Underlying Funds Held - Directly Managed	The carrying values of assets and liabilities underlying the funds held - directly managed account as at December 31, 2016 were as follows: December 31, Fixed maturity investments: U.S. government and agency $ 47,885 Non-U.S. government 5,961 Corporate 663,556 Municipal 38,927 Commercial mortgage-backed 151,395 Asset-backed 79,806 Total fixed maturity investments $ 987,530 Other assets $ 7,135 $ 994,665
Contractual Maturities of Fixed Maturity Investments Underlying Funds Held - Directly Managed	The contractual maturities of our fixed maturity investments underlying the funds held - directly managed account 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 at December 31, 2016 Amortized Cost Fair Value % of Total Fair Value One year or less $ 5,027 $ 5,026 0.5 % More than one year through two years 20,641 20,613 2.1 % More than two years through five years 301,119 296,685 30.0 % More than five years through ten years 253,811 244,967 24.9 % More than ten years 197,236 189,038 19.1 % Commercial mortgage-backed 158,129 151,395 15.3 % Asset-backed 79,885 79,806 8.1 % $ 1,015,848 $ 987,530 100.0 %
Funds Held - Directly Managed, by Credit Rating	The following table sets forth the credit ratings of our fixed maturity investments underlying the funds held - directly managed account as of December 31, 2016 . Amortized Cost Fair Value % of Total Investments AAA Rated AA Rated A Rated BBB Rated U.S. government and agency $ 50,257 $ 47,885 4.9 % $ 47,885 $ — $ — $ — Non-U.S. government 6,020 5,961 0.6 % — — 2,913 3,048 Corporate 681,484 663,556 67.2 % 5,549 63,809 234,975 359,223 Municipal 40,073 38,927 3.9 % — 12,839 26,088 — Commercial mortgage-backed 158,129 151,395 15.3 % 146,429 3,015 1,951 — Asset-backed 79,885 79,806 8.1 % 76,130 3,676 — — Total $ 1,015,848 $ 987,530 100.0 % $ 275,993 $ 83,339 $ 265,927 $ 362,271 % of total fair value 28.0 % 8.4 % 26.9 % 36.7 %
Net Realized and Unrealized Investment (Losses) Gains	Net realized and unrealized gains (losses) and change in fair value of embedded derivative for the year ended December 31, 2016 are summarized as follows: 2016 Net realized gains (losses) on fixed maturity securities $ (14,616 ) Change in fair value of embedded derivative (28,317 ) Net realized gains (losses) and change in fair value of embedded derivative $ (42,933 )
Net Investment Income	Major categories of net investment income underlying the funds held - directly managed for the year ended December 31, 2016 are summarized as follows: 2016 Fixed maturity investments $ 5,705 Short-term investments and cash and cash equivalents 64 Investment income on funds held - directly managed $ 5,769

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Categorized Investments Recorded at Fair Value among Levels	We have categorized our investments that are recorded at fair value on a recurring basis among levels based on the observability of inputs as follows: December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Investments: U.S. government and agency $ — $ 852,984 $ — $ 852,984 Non-U.S. government — 352,786 — 352,786 Corporate — 2,471,444 74,534 2,545,978 Municipal — 53,757 — 53,757 Residential mortgage-backed — 374,055 — 374,055 Commercial mortgage-backed — 204,999 12,213 217,212 Asset-backed — 467,463 14,692 482,155 Equities — U.S. 91,287 3,760 — 95,047 Other investments — 357,438 76,878 434,316 $ 91,287 $ 5,138,686 $ 178,317 $ 5,408,290 Funds Held - Directly Managed: U.S. government and agency $ — $ 47,885 $ — $ 47,885 Non-U.S. government — 5,961 — 5,961 Corporate — 663,556 — 663,556 Residential mortgage-backed — 38,927 — 38,927 Commercial mortgage-backed — 151,395 — 151,395 Asset-backed — 79,806 — 79,806 Other assets — 7,135 — 7,135 $ — $ 994,665 $ — $ 994,665 Other Assets: Derivative Instruments $ — $ 2,930 $ — $ 2,930 $ — $ 2,930 $ — $ 2,930 Other Liabilities: Derivative Instruments $ — $ 74 $ — $ 74 $ — $ 74 $ — $ 74 December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Fair Value Investments: U.S. government and agency $ — $ 767,759 $ — $ 767,759 Non-U.S. government — 423,954 — 423,954 Corporate — 2,745,002 — 2,745,002 Municipal — 28,174 — 28,174 Residential mortgage-backed — 382,288 — 382,288 Commercial mortgage-backed — 206,143 26,704 232,847 Asset-backed — 415,462 120,440 535,902 Equities — U.S. 99,467 9,326 — 108,793 Equities — International 2,702 — — 2,702 Other investments — 321,076 77,016 398,092 Total investments $ 102,169 $ 5,299,184 $ 224,160 $ 5,625,513
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share	The following table reconciles our other investments in the tables above with the amounts presented on our consolidated balance sheets: Other investments: December 31, 2016 December 31, 2015 Other investments measured at fair value $ 434,316 $ 398,092 Other investments measured at NAV as practical expedient 502,731 582,197 Total other investments shown on balance sheets $ 937,047 $ 980,289
Reconciliation of Beginning and Ending Balances for All Investments Measured at Fair Value on Recurring Basis	The following table presents a reconciliation of the beginning and ending balances for all investments measured at fair value on a recurring basis using Level 3 inputs during the years ended December 31, 2016 and 2015 : 2016 2015 Fixed Other Investments Equity Securities Total Fixed Other Investments Equity Securities Total Beginning fair value $ 147,144 $ 77,016 $ — $ 224,160 $ 600 $ 42,267 $ 4,850 $ 47,717 Purchases 58,552 6,885 — 65,437 — 106,433 — 106,433 Sales (52,841 ) (12,933 ) — (65,774 ) (600 ) (46,084 ) (5,000 ) (51,684 ) Total realized and unrealized gains (losses) (3,222 ) 5,910 — 2,688 — (25,600 ) 150 (25,450 ) Net transfers into (out of) Level 3 (48,194 ) — — (48,194 ) 147,144 — — 147,144 Ending fair value $ 101,439 $ 76,878 $ — $ 178,317 $ 147,144 $ 77,016 $ — $ 224,160

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Foreign Currency Forward Exchange Contracts	The following table presents the gross notional amounts, estimated fair values recorded within other assets and liabilities and the amounts of the net gains deferred in the currency translation adjustment account which is a component of accumulated other comprehensive income (loss) ("AOCI"), in shareholders' equity, related to our foreign currency forward exchange rate contracts as at December 31, 2016 . December 31, 2016 Fair Value Amount of Gains Deferred in AOCI (Effective Portion) Gross Notional Amount Assets Liabilities Year Ended December 31, 2016 Foreign exchange forward - AUD $ 45,467 $ 2,753 $ 74 $ 2,568 Foreign exchange forward - CAD 37,175 177 — 1,186 Total qualifying hedges $ 82,642 $ 2,930 $ 74 $ 3,754

Reinsurance Balances Recovera46

Reinsurance Balances Recoverable (Tables)	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
Summary of Reinsurance Reserves Recoverable	The following table provides the total reinsurance balances recoverable as at December 31, 2016 and, 2015 : 2016 Non-life Run-off Atrium StarStone Life and Annuities Total Recoverable from reinsurers on unpaid: Outstanding losses $ 621,288 $ 6,438 $ 182,478 $ 190 $ 810,394 IBNR 393,550 21,753 178,259 — 593,562 Fair value adjustments (13,885 ) 1,818 (3,506 ) — (15,573 ) Total reinsurance reserves recoverable 1,000,953 30,009 357,231 190 1,388,383 Paid losses recoverable 47,160 (1,081 ) 25,512 769 72,360 $ 1,048,113 $ 28,928 $ 382,743 $ 959 $ 1,460,743 2015 Non-life Run-off Atrium StarStone Life and Annuities Total Recoverable from reinsurers on unpaid: Outstanding losses $ 587,164 $ 6,772 $ 182,076 $ 1,544 $ 777,556 IBNR 465,211 16,581 123,732 — 605,524 Fair value adjustments (17,628 ) 2,499 (6,025 ) — (21,154 ) Total reinsurance reserves recoverable 1,034,747 25,852 299,783 1,544 1,361,926 Paid losses recoverable 72,213 430 16,568 784 89,995 $ 1,106,960 $ 26,282 $ 316,351 $ 2,328 $ 1,451,921 The following table shows our reinsurance balances recoverable by rating of reinsurer and our provisions for uncollectible reinsurance balances recoverable ("provisions for bad debt") as at December 31, 2016 and 2015 . The provisions for bad debt all relate to the Non-life Run-off segment. 2016 2015 Gross Provisions for Bad Debt Net Provisions as a Gross Provisions for Bad Debt Net Provisions as a Reinsurers rated A- or above $ 892,776 $ 35,184 $ 857,592 3.9 % $ 1,029,844 $ 46,969 $ 982,875 4.6 % Reinsurers rated below A-, secured 544,894 — 544,894 — % 388,399 — 388,399 — % Reinsurers rated below A-, unsecured 197,589 139,332 58,257 70.5 % 244,005 163,358 80,647 66.9 % Total $ 1,635,259 $ 174,516 $ 1,460,743 10.7 % $ 1,662,248 $ 210,327 $ 1,451,921 12.7 % The following tables provide a summary of net premiums written and earned in our Non-life Run-off, Atrium, StarStone and Life and Annuities segments for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Premiums Written Premiums Earned Premiums Written Premiums Earned Premiums Written Premiums Earned Non-life Run-off Gross $ 17,316 $ 25,989 $ 38,704 $ 116,494 $ 12,818 $ 45,684 Ceded (8,114 ) (9,234 ) (16,110 ) (72,125 ) (2,546 ) (14,516 ) Net $ 9,202 $ 16,755 $ 22,594 $ 44,369 $ 10,272 $ 31,168 Atrium Gross $ 143,170 $ 140,438 $ 149,082 $ 149,310 $ 154,248 $ 153,816 Ceded (2,733 ) (16,022 ) (14,502 ) (14,635 ) (17,973 ) (17,871 ) Net $ 140,437 $ 124,416 $ 134,580 $ 134,675 $ 136,275 $ 135,945 StarStone Gross $ 854,699 $ 830,186 $ 824,714 $ 769,875 $ 512,219 $ 528,135 Ceded (206,663 ) (153,578 ) (196,287 ) (196,729 ) (113,045 ) (154,502 ) Net $ 648,036 $ 676,608 $ 628,427 $ 573,146 $ 399,174 $ 373,633 Life and Annuities Life $ 6,261 $ 5,735 $ 1,553 $ 1,554 $ 2,235 $ 2,245 Total $ 803,936 $ 823,514 $ 787,154 $ 753,744 $ 547,956 $ 542,991
Reinsurance Balances Recoverable by Reinsurer	Top Ten Reinsurers December 31, 2016 December 31, 2015 Non-life Atrium StarStone Life and Total % of Non-life Atrium StarStone Life and Total % of Top ten reinsurers $ 737,074 $ 23,245 $ 226,283 $ — $ 986,602 67.6 % $ 713,743 $ 21,394 $ 155,171 $ — $ 890,308 61.4 % Other reinsurers > $1 million 301,856 4,827 152,341 — 459,024 31.4 % 383,898 4,253 158,417 — 546,568 37.6 % Other reinsurers < $1 million 9,183 856 4,119 959 15,117 1.0 % 9,319 635 2,763 2,328 15,045 1.0 % Total $ 1,048,113 $ 28,928 $ 382,743 $ 959 $ 1,460,743 100.0 % $ 1,106,960 $ 26,282 $ 316,351 $ 2,328 $ 1,451,921 100.0 %

Losses and Loss Adjustment Ex47

Losses and Loss Adjustment Expenses (Tables)	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
Total Losses and Loss Adjustment Expense Liabilities, and Reconciliation of Beginning and Ending Balances	The table below provides a reconciliation of the beginning and ending liability for losses and LAE for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Balance as at January 1 $ 201,017 $ 212,611 $ 215,392 Less: reinsurance reserves recoverable 25,852 28,278 25,055 Net balance as at January 1 175,165 184,333 190,337 Net incurred losses and LAE: Current period 71,358 69,400 74,094 Prior periods (12,971 ) (21,921 ) (18,666 ) Total net incurred losses and LAE 58,387 47,479 55,428 Net paid losses: Current period (23,582 ) (21,145 ) (29,626 ) Prior periods (24,416 ) (30,890 ) (27,985 ) Total net paid losses (47,998 ) (52,035 ) (57,611 ) Effect of exchange rate movement (3,441 ) (4,612 ) (3,821 ) Acquired on purchase of subsidiaries — — — Net balance as at December 31 182,113 175,165 184,333 Plus: reinsurance reserves recoverable 30,009 25,852 28,278 Balance as at December 31 $ 212,122 $ 201,017 $ 212,611 The table below provides a reconciliation of the beginning and ending liability for losses and LAE for the years ended December 31, 2016 , 2015 and 2014: 2016 2015 2014 Balance as at January 1 $ 933,678 $ 861,800 $ — Less: reinsurance reserves recoverable 299,783 325,209 — Net balance as at January 1 633,895 536,591 — Net incurred losses and LAE: Current period 415,829 367,040 229,488 Prior periods (14,236 ) (39,356 ) (11,059 ) Total net incurred losses and LAE 401,593 327,684 218,429 Net paid losses: Current period (52,128 ) (62,739 ) (49,489 ) Prior periods (199,125 ) (149,820 ) (80,315 ) Total net paid losses (251,253 ) (212,559 ) (129,804 ) Effect of exchange rate movement (15,984 ) (17,821 ) (16,716 ) Acquired on purchase of subsidiaries — — 464,682 Assumed business — — — Ceded business (66,100 ) — — Net balance as at December 31 702,151 633,895 536,591 Plus: reinsurance reserves recoverable 357,231 299,783 325,209 Balance as at December 31 $ 1,059,382 $ 933,678 861,800 The table below provides a reconciliation of the beginning and ending reserves for losses and LAE for the years ended December 31, 2016 , 2015 and 2014 for the Non-life Run-off segment: 2016 2015 2014 Balance as at January 1 $ 4,585,454 $ 3,435,010 $ 4,004,513 Less: reinsurance reserves recoverable 1,034,747 800,709 1,121,533 Less: deferred charge on retroactive reinsurance 255,911 — — Net balance as at January 1 3,294,796 2,634,301 2,882,980 Net incurred losses and LAE: Current period 5,829 39,924 24,235 Prior periods (291,710 ) (310,754 ) (288,946 ) Total net incurred losses and LAE (285,881 ) (270,830 ) (264,711 ) Net paid losses: Current period (3,869 ) (16,049 ) (87,681 ) Prior periods (529,937 ) (501,246 ) (312,415 ) Total net paid losses (533,806 ) (517,295 ) (400,096 ) Effect of exchange rate movement (27,478 ) (42,636 ) (49,267 ) Acquired on purchase of subsidiaries 10,019 878,815 436,765 Assumed business 1,340,444 612,441 28,630 Ceded business (177,235 ) — — Net balance as at December 31 3,620,859 3,294,796 2,634,301 Plus: reinsurance reserves recoverable 1,000,953 1,034,747 800,709 Plus: deferred charge on retroactive reinsurance 94,551 255,911 — Balance as at December 31 $ 4,716,363 $ 4,585,454 $ 3,435,010 The following table summarizes the liability for losses and LAE by segment as at December 31, 2016 and 2015 : 2016 2015 Non-life Run-off Atrium StarStone Total Non-life Atrium StarStone Total Outstanding losses $ 2,697,737 $ 67,379 $ 502,115 $ 3,267,231 $ 2,757,774 $ 68,913 $ 457,175 $ 3,283,862 IBNR 2,153,994 132,240 558,130 2,844,364 1,991,009 115,613 477,990 2,584,612 Fair value adjustments (135,368 ) 12,503 (863 ) (123,728 ) (163,329 ) 16,491 (1,487 ) (148,325 ) Total $ 4,716,363 $ 212,122 $ 1,059,382 $ 5,987,867 $ 4,585,454 $ 201,017 $ 933,678 $ 5,720,149 The table below provides a consolidated reconciliation of the beginning and ending liability for losses and LAE for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Balance as at January 1 $ 5,720,149 $ 4,509,421 $ 4,219,905 Less: reinsurance reserves recoverable 1,360,382 1,154,196 1,146,588 Less: deferred charge on retroactive reinsurance 255,911 — — Net balance as at January 1 4,103,856 3,355,225 3,073,317 Net incurred losses and LAE: Current period 493,016 476,364 327,817 Prior periods (318,917 ) (372,031 ) (318,671 ) Total net incurred losses and LAE 174,099 104,333 9,146 Net paid losses: Current period (79,579 ) (99,933 ) (166,796 ) Prior periods (753,478 ) (681,956 ) (420,715 ) Total net paid losses (833,057 ) (781,889 ) (587,511 ) Effect of exchange rate movement (46,903 ) (65,069 ) (69,804 ) Acquired on purchase of subsidiaries 10,019 878,815 901,447 Assumed business 1,340,444 612,441 28,630 Ceded business (243,335 ) — — Net balance as at December 31 4,505,123 4,103,856 3,355,225 Plus: reinsurance reserves recoverable 1,388,193 1,360,382 1,154,196 Plus: deferred charge on retroactive reinsurance 94,551 $ 255,911 — Balance as at December 31 $ 5,987,867 $ 5,720,149 $ 4,509,421
Schedule of Incurred Losses	Net incurred losses and LAE in the Atrium segment for the years ended December 31, 2016 , 2015 and 2014 were as follows: 2016 2015 2014 Prior Period Current Period Total Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 24,416 $ 23,582 $ 47,998 $ 30,890 $ 21,145 $ 52,035 $ 27,985 $ 29,626 $ 57,611 Net change in case and LAE reserves (13,115 ) 12,967 (148 ) (18,213 ) 17,504 (709 ) (16,986 ) 14,302 (2,684 ) Net change in IBNR reserves (20,543 ) 34,243 13,700 (27,382 ) 30,226 2,844 (18,114 ) 29,671 11,557 Increase (reduction) in estimates of net ultimate losses (9,242 ) 70,792 61,550 (14,705 ) 68,875 54,170 (7,115 ) 73,599 66,484 Increase (reduction) in provisions for unallocated LAE (421 ) 566 145 (608 ) 525 (83 ) (486 ) 495 9 Amortization of fair value adjustments (3,308 ) — (3,308 ) (6,608 ) — (6,608 ) (11,065 ) — (11,065 ) Net incurred losses and LAE $ (12,971 ) $ 71,358 $ 58,387 $ (21,921 ) $ 69,400 $ 47,479 $ (18,666 ) $ 74,094 $ 55,428 Net incurred losses and LAE for the years ended December 31, 2016 and 2015 were as follows: 2016 2015 Prior Current Total Prior Current Total Net losses paid $ 199,125 $ 52,128 $ 251,253 $ 149,820 $ 62,739 $ 212,559 Net change in case and LAE reserves (51,309 ) 124,358 73,049 15,772 61,447 77,219 Net change in IBNR reserves (156,546 ) 232,189 75,643 (200,730 ) 238,634 37,904 Increase (reduction) in estimates of net ultimate losses (8,730 ) 408,675 399,945 (35,138 ) 362,820 327,682 Increase (reduction) in provisions for unallocated LAE (3,611 ) 7,154 3,543 (683 ) 4,220 3,537 Amortization of fair value adjustments (1,895 ) — (1,895 ) (3,535 ) — (3,535 ) Net incurred losses and LAE $ (14,236 ) $ 415,829 $ 401,593 $ (39,356 ) $ 367,040 $ 327,684 Net incurred losses and LAE in the Non-life Run-off segment for the years ended December 31, 2016 , 2015 and 2014 were as follows: 2016 2015 2014 Prior Period Current Period Total Prior Period Current Period Total Prior Period Current Period Total Net losses paid $ 529,937 $ 3,869 $ 533,806 $ 501,246 $ 16,049 $ 517,295 $ 312,415 $ 87,681 $ 400,096 Net change in case and LAE reserves (608,168 ) (617 ) (608,785 ) (366,262 ) 10,927 (355,335 ) (285,814 ) (24,600 ) (310,414 ) Net change in IBNR reserves (349,726 ) 2,342 (347,384 ) (377,722 ) 12,948 (364,774 ) (262,384 ) (39,400 ) (301,784 ) Amortization of deferred charges 168,827 — 168,827 15,265 — 15,265 — — — Increase (reduction) in estimates of net ultimate losses (259,130 ) 5,594 (253,536 ) (227,473 ) 39,924 (187,549 ) (235,783 ) 23,681 (212,102 ) Increase (reduction) in provisions for bad debt (13,822 ) — (13,822 ) (25,271 ) — (25,271 ) (7,700 ) — (7,700 ) Increase (reduction) in provisions for unallocated LAE (44,190 ) 235 (43,955 ) (62,653 ) — (62,653 ) (49,445 ) 554 (48,891 ) Amortization of fair value adjustments 25,432 — 25,432 4,643 — 4,643 3,982 — 3,982 Net incurred losses and LAE $ (291,710 ) $ 5,829 $ (285,881 ) $ (310,754 ) $ 39,924 $ (270,830 ) $ (288,946 ) $ 24,235 $ (264,711 ) The tables below provide the components of net incurred losses and LAE by segment for the years ended December 31, 2016 , 2015 and 2014 : Year Ended December 31, 2016 Non-life Atrium StarStone Total Net losses paid $ 533,806 $ 47,998 $ 251,253 $ 833,057 Net change in case and LAE reserves (608,785 ) (148 ) 73,049 (535,884 ) Net change in IBNR reserves (347,384 ) 13,700 75,643 (258,041 ) Amortization of deferred charges 168,827 — — 168,827 Increase (reduction) in estimates of net ultimate losses (253,536 ) 61,550 399,945 207,959 Reduction in provisions for bad debt (13,822 ) — — (13,822 ) Increase (reduction) in provisions for unallocated LAE (43,955 ) 145 3,543 (40,267 ) Amortization of fair value adjustments 25,432 (3,308 ) (1,895 ) 20,229 Net incurred losses and LAE $ (285,881 ) $ 58,387 $ 401,593 $ 174,099 Year Ended December 31, 2015 Non-life Run-off Atrium StarStone Total Net losses paid $ 517,295 $ 52,035 $ 212,559 $ 781,889 Net change in case and LAE reserves (355,335 ) (709 ) 77,219 (278,825 ) Net change in IBNR reserves (364,774 ) 2,844 37,904 (324,026 ) Amortization of deferred charges 15,265 — — 15,265 Increase (reduction) in estimates of net ultimate losses (187,549 ) 54,170 327,682 194,303 Reduction in provisions for bad debt (25,271 ) — — (25,271 ) Increase (reduction) in provisions for unallocated LAE (62,653 ) (83 ) 3,537 (59,199 ) Amortization of fair value adjustments 4,643 (6,608 ) (3,535 ) (5,500 ) Net incurred losses and LAE $ (270,830 ) $ 47,479 $ 327,684 $ 104,333 Year Ended December 31, 2014 Non-life Atrium StarStone Total Net losses paid $ 400,096 $ 57,611 $ 129,804 $ 587,511 Net change in case and LAE reserves (310,414 ) (2,684 ) 37,604 (275,494 ) Net change in IBNR reserves (301,784 ) 11,557 58,870 (231,357 ) Amortization of deferred charges — — — — Increase (reduction) in estimates of net ultimate losses (212,102 ) 66,484 226,278 80,660 Increase in provisions for bad debt (7,700 ) — — (7,700 ) Reduction in provisions for unallocated LAE (48,891 ) 9 (5,088 ) (53,970 ) Amortization of fair value adjustments 3,982 (11,065 ) (2,761 ) (9,844 ) Net incurred losses and LAE $ (264,711 ) $ 55,428 $ 218,429 $ 9,146
Schedule of Gross and Net Losses and LAE Reserves by Category	The following table provides a breakdown of the gross and net losses and LAE reserves by major category as at December 31, 2016: 2016 2016 Gross Net OLR IBNR Total OLR IBNR Total (in thousands of U.S. dollars) Asbestos $ 240,863 $ 548,180 $ 789,043 $ 230,983 $ 533,361 $ 764,344 Environmental 94,432 67,646 162,078 91,362 65,507 156,869 General casualty 427,733 316,227 743,960 301,699 190,053 491,752 Workers' compensation/personal accident 1,360,743 693,585 2,054,328 915,704 457,119 1,372,823 Marine, aviation and transit 45,240 34,873 80,113 39,816 34,678 74,494 Construction defect 39,622 120,459 160,081 32,449 88,647 121,096 Other 407,490 100,934 508,424 325,734 95,411 421,145 Total $ 2,616,123 $ 1,881,904 $ 4,498,027 $ 1,937,747 $ 1,464,776 $ 3,402,523 ULAE 218,336 218,336 Total $ 4,716,363 $ 3,620,859
Incurred and Paid Loss Development Information, and IBNR Liabilities and Cumulative Loss Frequency	Information about total IBNR liabilities and cumulative loss frequency as at December 31, 2016, including expected development on reported claims included within the net incurred losses and allocated LAE amounts for the StarStone segment, are set forth in the table below: As at December 31, 2016 Accident Year Incurred Losses and ALAE, Net of Reinsurance Total of IBNR plus Expected Development on Reported Losses Cumulative Number of Reported Claims 2007 $ 19,513 $ — 1,254 2008 48,609 — 1,715 2009 46,277 309 2,253 2010 160,093 763 4,247 2011 322,684 5,067 8,997 2012 329,426 18,372 11,098 2013 297,213 30,226 12,414 2014 279,432 55,291 15,057 2015 372,016 96,665 21,721 2016 271,950 136,314 17,074 Information about total IBNR liabilities and cumulative loss frequency as at December 31, 2016, including expected development on reported claims included within the net incurred losses and allocated LAE amounts for the Atrium segment, are set forth in the table below: As at December 31, 2016 Accident Year Incurred Losses and ALAE, Net of Reinsurance Total of IBNR plus Expected Development on Reported Losses Cumulative Number of Reported Claims 2007 $ 60,302 $ 1,610 282 2008 61,473 2,403 345 2009 45,060 1,822 377 2010 45,416 3,141 515 2011 67,924 3,926 765 2012 52,929 4,821 1,028 2013 55,288 7,694 1,582 2014 63,592 14,309 2,563 2015 67,927 23,553 3,936 2016 67,933 39,742 3,881 The following tables set forth information about incurred and paid loss development information for the Atrium segment as at December 31, 2016. The information related to incurred and paid loss development for the years ended December 31, 2007 through 2015 is presented as supplementary information and is unaudited. Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 39,003 $ 68,768 $ 62,305 $ 68,567 $ 68,842 $ 61,858 $ 60,418 $ 61,660 $ 60,162 $ 60,302 2008 58,537 74,652 75,261 71,965 69,378 62,490 62,217 62,969 61,473 2009 55,579 67,728 58,778 53,799 50,169 46,927 45,693 45,060 2010 76,056 70,280 57,182 51,139 50,202 45,960 45,416 2011 92,093 86,086 72,671 71,744 69,533 67,924 2012 71,370 58,991 56,729 55,091 52,929 2013 57,318 64,243 59,150 55,288 2014 62,613 65,737 63,592 2015 63,954 67,927 2016 67,933 Total $ 587,844 Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For The Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 13,878 $ 35,836 $ 41,837 $ 46,467 $ 48,544 $ 50,028 $ 54,298 $ 54,611 $ 55,857 $ 56,806 2008 15,060 36,785 47,151 51,838 54,750 56,563 57,760 58,320 57,891 2009 11,719 27,103 33,910 37,337 39,280 40,443 41,102 41,375 2010 11,243 24,678 31,653 35,859 38,293 39,294 39,868 2011 16,777 39,167 51,288 57,332 61,197 62,515 2012 11,059 31,041 37,532 41,677 43,929 2013 14,398 31,669 39,904 42,942 2014 17,359 33,830 40,907 2015 11,874 29,235 2016 13,513 Total $ 428,981 All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance 10,443 Total outstanding liabilities for unpaid losses and LAE, net of reinsurance $ 169,306 The following tables set forth information about incurred and paid loss development information for the StarStone segment as at December 31, 2016. The information related to incurred and paid loss development for the years ended December 31, 2014 through 2015 is presented as supplementary information and is unaudited. This business was acquired on April 1, 2014, as described in Note 3 - "Acquisitions". The information in the incurred and paid loss development tables below is presented on a prospective basis from the date of our acquisition of StarStone; as providing pre-acquisition incurred losses by accident year for years prior to 2014 was determined to be impracticable. Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 18,453 $ 17,532 $ 19,513 2008 50,984 48,558 48,609 2009 45,340 39,411 46,277 2010 174,838 158,845 160,093 2011 324,625 308,384 322,684 2012 365,135 347,626 329,426 2013 342,406 308,840 297,213 2014 248,702 292,595 279,432 2015 365,426 372,016 2016 271,950 Total $ 2,147,213 Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For The Years Ended December 31, Accident Year 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 18,955 $ 18,986 $ 18,807 2008 48,991 49,170 48,734 2009 46,183 46,328 46,146 2010 145,427 155,431 154,101 2011 284,252 307,799 310,686 2012 224,506 260,323 278,308 2013 141,467 188,397 221,989 2014 42,486 113,340 163,515 2015 66,593 165,701 2016 57,753 Total $ 1,465,740 All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance 1,210 Total outstanding liabilities for unpaid losses and LAE, net of reinsurance $ 682,683 The following tables set forth information about incurred and paid loss development information related to our workers' compensation category within the Non-life Run-off segment as at December 31, 2016. The information related to incurred and paid loss development for the years ended December 31, 2007 through 2015 is presented as supplementary information and is unaudited. Unpaid Reported Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) 2007 $ 106,913 $ 85,044 $ 72,373 $ 68,929 $ 59,768 $ 47,688 $ 51,970 $ 57,819 $ 31,975 $ 22,457 2008 103,568 93,156 86,070 68,516 48,864 42,524 36,483 28,878 22,378 2009 83,064 96,353 75,756 49,318 39,846 34,033 34,730 26,589 2010 104,493 111,772 75,569 56,334 44,754 42,383 34,640 2011 84,408 80,618 55,414 63,975 48,552 31,324 2012 66,109 65,078 79,952 62,339 40,728 2013 35,976 63,372 56,882 37,299 2014 14,179 25,152 20,144 2015 6,017 4,104 2016 209 Total $ 239,872 IBNR Losses and Loss Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) 2007 $ 87,248 $ 38,830 $ 23,382 $ 9,993 $ 8,498 $ 7,006 $ 8,794 $ 7,450 $ 4,180 $ 8,488 2008 78,862 43,067 18,966 15,087 11,065 12,420 10,624 6,449 11,586 2009 77,265 35,477 19,247 16,686 11,426 9,391 11,165 16,294 2010 67,115 16,597 14,819 17,772 28,348 26,945 24,435 2011 69,544 24,162 15,610 54,890 46,320 34,572 2012 86,194 45,307 95,026 71,755 48,173 2013 43,419 110,706 75,839 48,022 2014 51,216 45,657 24,705 2015 9,596 2,846 2016 530 Total $ 219,651 The table below provides a summary of IBNR acquired in assumed loss portfolio transfer reinsurance transactions which is reflected on a prospective basis in the table above from the year in which the transaction occurred: For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) Take-On IBNR for Assumed Business $ — $ — $ 5,323 $ 5,954 $ — $ — $ — $ — $ — $ 100,000 Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 267,160 $ 275,598 $ 293,677 $ 308,723 $ 323,278 $ 326,776 $ 345,358 $ 358,015 $ 335,568 $ 336,989 2008 265,651 300,657 325,463 341,690 342,397 354,645 361,369 357,863 361,402 2009 236,306 278,324 294,062 303,106 310,848 320,485 329,178 335,481 2010 256,618 291,192 308,810 326,412 337,002 344,185 347,575 2011 197,858 212,973 222,037 251,058 254,815 249,040 2012 189,571 198,054 230,513 225,014 221,803 2013 97,190 131,198 113,792 104,521 2014 73,154 82,487 77,180 2015 19,151 13,129 2016 873 Total $ 2,047,993 Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For The Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 72,998 $ 151,725 $ 197,923 $ 229,800 $ 255,011 $ 272,082 $ 284,594 $ 292,746 $ 299,413 $ 306,044 2008 83,221 164,433 220,427 258,086 282,468 299,701 314,261 322,537 327,438 2009 75,977 146,494 199,059 237,103 259,577 277,061 283,283 292,598 2010 85,009 162,822 218,422 252,306 263,900 274,857 288,499 2011 43,906 108,193 151,012 132,194 159,942 183,144 2012 37,267 87,669 55,534 90,921 132,902 2013 17,795 (42,879 ) (18,929 ) 19,200 2014 7,760 11,678 32,332 2015 3,538 6,178 2016 134 Total $ 1,588,469 All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance 1,042,179 Total outstanding liabilities for unpaid losses and LAE, net of reinsurance $ 1,501,703 Information about total IBNR liabilities and cumulative loss frequency as at December 31, 2016, including expected development on reported claims included within the net incurred losses and allocated LAE amounts for the Non-life Run-off segment for the general casualty category, are set forth in the table below: As at December 31, 2016 Accident Year Incurred Losses and ALAE, Net of Reinsurance Total of IBNR plus Expected Development on Reported Losses Cumulative Number of Reported Claims 2007 $ 88,081 $ 1,579 15,904 2008 155,909 4,682 10,363 2009 173,855 5,247 10,378 2010 270,864 18,026 12,439 2011 191,245 20,683 10,247 2012 280,266 21,224 22,667 2013 122,148 16,534 15,136 2014 42,370 9,894 3,421 2015 16,292 7,573 871 2016 2,690 2,226 111 Information about total IBNR liabilities and cumulative loss frequency as at December 31, 2016, including expected development on reported claims included within the net incurred losses and allocated LAE amounts for the Non-life Run-off segment for workers' compensation, are set forth in the table below: As at December 31, 2016 Accident Year Incurred Losses and ALAE, Net of Reinsurance Total of IBNR plus Expected Development on Reported Losses Cumulative Number of Reported Claims 2007 $ 336,989 $ 8,488 44,305 2008 361,402 11,586 40,849 2009 335,481 16,294 41,127 2010 347,575 24,435 48,360 2011 249,040 34,572 46,975 2012 221,803 48,173 42,712 2013 104,521 48,022 22,189 2014 77,180 24,705 10,857 2015 13,129 2,846 2,869 2016 873 530 33 The following tables set forth information about incurred and paid loss development information related to our general casualty category within the Non-life Run-off segment as at December 31, 2016. The information related to incurred and paid loss development for the years ended December 31, 2007 through 2015 is presented as supplementary information and is unaudited. Unpaid Reported Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) 2007 $ 22,745 $ 26,555 $ 13,847 $ 10,053 $ 15,084 $ 8,757 $ 7,411 $ 6,302 $ 1,929 $ 2,679 2008 43,164 55,854 36,785 29,183 21,275 16,296 11,239 9,138 7,890 2009 19,205 37,028 45,685 34,708 22,834 15,044 14,562 11,333 2010 41,785 92,211 81,789 59,566 42,088 35,806 23,460 2011 19,805 48,609 33,465 32,499 25,227 19,945 2012 44,029 56,594 53,386 37,651 34,804 2013 20,677 23,432 22,681 16,995 2014 10,489 12,537 10,022 2015 3,294 4,356 2016 — 248 Total $ 131,732 IBNR Losses and Loss Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) 2007 $ 8,983 $ 8,409 $ 6,108 $ 6,339 $ 7,485 $ 2,986 $ 3,996 $ 3,356 $ 1,049 $ 1,579 2008 16,731 4,956 15,134 12,253 5,605 7,528 6,491 8,450 4,682 2009 14,131 16,784 15,393 8,240 12,272 9,170 5,363 5,247 2010 22,364 25,904 16,032 28,064 19,770 13,513 18,026 2011 33,180 23,948 34,767 25,659 18,042 20,683 2012 61,807 64,756 45,872 19,383 21,224 2013 70,755 58,446 17,200 16,534 2014 32,309 12,839 9,894 2015 7,697 7,573 2016 2,226 Total $ 107,668 The table below provides a summary of IBNR acquired in assumed loss portfolio transfer reinsurance transactions which is reflected on a prospective basis in the table above from the year in which the transaction occurred: For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 (unaudited) Take-On IBNR for Assumed Business $ — $ 10,740 $ — $ 3,633 $ — $ 25,703 $ — $ 5,263 $ 3,685 $ 36,501 Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 50,012 $ 69,095 $ 77,504 $ 81,587 $ 92,460 $ 86,583 $ 89,022 $ 87,929 $ 86,364 $ 88,081 2008 78,187 114,684 137,678 145,526 147,317 152,589 155,177 158,178 155,909 2009 47,683 95,064 128,373 146,500 164,233 168,363 173,304 173,855 2010 82,340 169,525 200,723 229,345 235,009 260,599 270,864 2011 73,694 134,667 166,450 177,382 186,384 191,245 2012 147,850 225,566 257,655 255,667 280,266 2013 117,545 135,171 113,574 122,148 2014 48,808 39,072 42,370 2015 12,949 16,292 2016 2,690 Total $ 1,343,720 Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For The Years Ended December 31, Accident Year 2007 (unaudited) 2008 (unaudited) 2009 (unaudited) 2010 (unaudited) 2011 (unaudited) 2012 (unaudited) 2013 (unaudited) 2014 (unaudited) 2015 (unaudited) 2016 2007 $ 18,284 $ 34,131 $ 57,548 $ 65,195 $ 69,892 $ 74,840 $ 77,614 $ 78,271 $ 83,386 $ 83,823 2008 18,292 53,874 85,759 104,090 120,437 128,766 137,448 140,589 143,337 2009 14,347 41,253 67,294 103,552 129,127 144,148 153,379 157,275 2010 18,191 51,410 102,903 141,715 173,150 211,280 229,377 2011 20,709 62,110 98,218 119,224 143,116 150,616 2012 42,014 104,216 158,397 198,634 224,238 2013 26,112 53,293 73,693 88,618 2014 6,010 13,696 22,454 2015 1,958 4,364 2016 216 Total $ 1,104,318 All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance 266,163 Total outstanding liabilities for unpaid losses and LAE, net of reinsurance $ 505,565
Reconciliation of Incurred and Paid Loss Development to Liability for Unpaid Losses and LAE	The reconciliation of incurred and paid loss development to the liability for unpaid losses and LAE as presented in the tables above for the year ended December 31, 2016 is set forth below: December 31, 2016 Liabilities for unpaid losses and allocated LAE, net of reinsurance $ 505,565 Reinsurance recoverable on unpaid losses 254,017 Fair value adjustments (15,622 ) Gross liability for unpaid losses and LAE before unallocated loss adjustment expenses 743,960 Unallocated loss adjustment expenses 36,112 Total gross liability for unpaid losses and LAE $ 780,072 The reconciliation of incurred and paid loss development to the liability for unpaid losses and LAE as presented in the tables above for the StarStone segment for the year ended December 31, 2016 is set forth below: December 31, 2016 Liabilities for unpaid losses and allocated LAE, net of reinsurance $ 682,683 Reinsurance recoverable on unpaid losses 360,737 Unallocated loss adjustment expenses 16,825 Fair value adjustments (863 ) Total gross liability for unpaid losses and LAE $ 1,059,382 The reconciliation of incurred and paid loss development to the liability for unpaid losses and LAE as presented in the tables above for the year ended December 31, 2016 is set forth below: December 31, 2016 Liabilities for unpaid losses and allocated LAE, net of reinsurance $ 1,501,703 Reinsurance recoverable on unpaid losses 592,394 Fair value adjustments (39,769 ) Gross liability for unpaid losses and LAE before unallocated loss adjustment expenses 2,054,328 Unallocated loss adjustment expenses 99,718 Total gross liability for unpaid losses and LAE $ 2,154,046 The reconciliation of incurred and paid loss development to the liability for unpaid losses and LAE as presented in the tables above for the Atrium segment for the year ended December 31, 2016 is set forth below: December 31, 2016 Liabilities for unpaid losses and allocated LAE, net of reinsurance $ 169,306 Reinsurance recoverable on unpaid losses $ 28,191 Unallocated loss adjustment expenses $ 2,122 Fair value adjustments $ 12,503 Total gross liability for unpaid losses and LAE $ 212,122
Average Annual Duration of Claims	The following is unaudited supplementary information for average annual historical duration of claims in the StarStone segment: Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10 StarStone 18.7 % 34.7 % 21.5 % 9.2 % 4.4 % 2.4 % — % — % — % — % The following is unaudited supplementary information for average annual historical duration of claims: Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10 Workers' compensation 19.6 % 20.4 % 17.5 % 10.2 % 7.0 % 5.0 % 3.2 % 2.5 % 1.7 % 2.0 % The following is unaudited supplementary information for average annual historical duration of claims: Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10 General casualty 12.9 % 18.6 % 19.6 % 13.3 % 10.6 % 7.5 % 5.2 % 1.7 % 3.8 % 0.5 % The following is unaudited supplementary information for average annual historical duration of claims in the Atrium segment: Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10 Atrium 23.5 % 32.1 % 14.2 % 7.8 % 4.6 % 2.4 % 2.9 % 0.7 % 2.1 % 1.6 %

Premiums Written and Earned (Ta

Premiums Written and Earned (Tables)	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
Schedule of Net Premiums Written and Earned	The following table provides the total reinsurance balances recoverable as at December 31, 2016 and, 2015 : 2016 Non-life Run-off Atrium StarStone Life and Annuities Total Recoverable from reinsurers on unpaid: Outstanding losses $ 621,288 $ 6,438 $ 182,478 $ 190 $ 810,394 IBNR 393,550 21,753 178,259 — 593,562 Fair value adjustments (13,885 ) 1,818 (3,506 ) — (15,573 ) Total reinsurance reserves recoverable 1,000,953 30,009 357,231 190 1,388,383 Paid losses recoverable 47,160 (1,081 ) 25,512 769 72,360 $ 1,048,113 $ 28,928 $ 382,743 $ 959 $ 1,460,743 2015 Non-life Run-off Atrium StarStone Life and Annuities Total Recoverable from reinsurers on unpaid: Outstanding losses $ 587,164 $ 6,772 $ 182,076 $ 1,544 $ 777,556 IBNR 465,211 16,581 123,732 — 605,524 Fair value adjustments (17,628 ) 2,499 (6,025 ) — (21,154 ) Total reinsurance reserves recoverable 1,034,747 25,852 299,783 1,544 1,361,926 Paid losses recoverable 72,213 430 16,568 784 89,995 $ 1,106,960 $ 26,282 $ 316,351 $ 2,328 $ 1,451,921 The following table shows our reinsurance balances recoverable by rating of reinsurer and our provisions for uncollectible reinsurance balances recoverable ("provisions for bad debt") as at December 31, 2016 and 2015 . The provisions for bad debt all relate to the Non-life Run-off segment. 2016 2015 Gross Provisions for Bad Debt Net Provisions as a Gross Provisions for Bad Debt Net Provisions as a Reinsurers rated A- or above $ 892,776 $ 35,184 $ 857,592 3.9 % $ 1,029,844 $ 46,969 $ 982,875 4.6 % Reinsurers rated below A-, secured 544,894 — 544,894 — % 388,399 — 388,399 — % Reinsurers rated below A-, unsecured 197,589 139,332 58,257 70.5 % 244,005 163,358 80,647 66.9 % Total $ 1,635,259 $ 174,516 $ 1,460,743 10.7 % $ 1,662,248 $ 210,327 $ 1,451,921 12.7 % The following tables provide a summary of net premiums written and earned in our Non-life Run-off, Atrium, StarStone and Life and Annuities segments for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Premiums Written Premiums Earned Premiums Written Premiums Earned Premiums Written Premiums Earned Non-life Run-off Gross $ 17,316 $ 25,989 $ 38,704 $ 116,494 $ 12,818 $ 45,684 Ceded (8,114 ) (9,234 ) (16,110 ) (72,125 ) (2,546 ) (14,516 ) Net $ 9,202 $ 16,755 $ 22,594 $ 44,369 $ 10,272 $ 31,168 Atrium Gross $ 143,170 $ 140,438 $ 149,082 $ 149,310 $ 154,248 $ 153,816 Ceded (2,733 ) (16,022 ) (14,502 ) (14,635 ) (17,973 ) (17,871 ) Net $ 140,437 $ 124,416 $ 134,580 $ 134,675 $ 136,275 $ 135,945 StarStone Gross $ 854,699 $ 830,186 $ 824,714 $ 769,875 $ 512,219 $ 528,135 Ceded (206,663 ) (153,578 ) (196,287 ) (196,729 ) (113,045 ) (154,502 ) Net $ 648,036 $ 676,608 $ 628,427 $ 573,146 $ 399,174 $ 373,633 Life and Annuities Life $ 6,261 $ 5,735 $ 1,553 $ 1,554 $ 2,235 $ 2,245 Total $ 803,936 $ 823,514 $ 787,154 $ 753,744 $ 547,956 $ 542,991

Goodwill, Intangible Assets a49

Goodwill, Intangible Assets and Deferred Charges (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill and Intangible Assets	The following tables present a reconciliation of the beginning and ending goodwill, intangible assets and deferred charges for the years ended December 31, 2016 and 2015 : 2016 Goodwill Intangible assets with a definite life - Other Intangible assets with an indefinite life Total Intangible assets with a definite life - FVA Other assets - Deferred Charges Balance as at January 1, 2016 $ 73,071 $ 31,202 $ 87,031 $ 191,304 $ 127,170 $ 255,911 Acquired during the year — — — — 37,005 7,467 Amortization — (6,449 ) — (6,449 ) (19,017 ) (168,827 ) Balance as at December 31, 2016 $ 73,071 $ 24,753 $ 87,031 $ 184,855 $ 145,158 $ 94,551 2015 Goodwill Intangible assets with a definite life - Other Intangible assets with an indefinite life Total Intangible assets with a definite life - FVA Other assets - Deferred Charges Balance as at January 1, 2015 $ 73,071 $ 41,048 $ 87,031 $ 201,150 $ 97,623 $ — Acquired during the year — — — — 23,968 271,176 Amortization — (9,846 ) — (9,846 ) 5,579 (15,265 ) Balance as at December 31, 2015 $ 73,071 $ 31,202 $ 87,031 $ 191,304 $ 127,170 $ 255,911 The gross carrying value, accumulated amortization and net carrying value of intangible assets by type and deferred charge at December 31, 2016 and 2015 were as follows: 2016 2015 Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value Intangible assets with a definite life: Fair value adjustments: Losses and LAE liabilities $ 458,202 $ (334,475 ) $ 123,727 $ 456,110 $ (307,785 ) $ 148,325 Reinsurance balances recoverable (175,924 ) 160,350 (15,574 ) (175,774 ) 154,619 (21,155 ) Other Assets (48,840 ) $ — (48,840 ) $ — $ — $ — Other Liabilities 85,845 $ — 85,845 $ — $ — $ — Total $ 319,283 $ (174,125 ) $ 145,158 $ 280,336 $ (153,166 ) $ 127,170 Other: Distribution channel $ 20,000 $ (4,111 ) $ 15,889 $ 20,000 $ (2,777 ) $ 17,223 Technology 15,000 (10,978 ) 4,022 15,000 (6,561 ) 8,439 Brand 7,000 (2,158 ) 4,842 12,000 (6,460 ) 5,540 Total $ 42,000 $ (17,247 ) $ 24,753 $ 47,000 $ (15,798 ) $ 31,202 Intangible assets with an indefinite life: Lloyd’s syndicate capacity $ 37,031 $ — $ 37,031 $ 37,031 $ — $ 37,031 Licenses 19,900 — 19,900 19,900 — 19,900 Management contract 30,100 — 30,100 30,100 — 30,100 Total $ 87,031 $ — $ 87,031 $ 87,031 $ — $ 87,031 Deferred charges on retroactive reinsurance $ 278,643 $ (184,092 ) $ 94,551 271,176 (15,265 ) 255,911
Summary of Estimated Amortization Expense of Intangible Assets	The estimated amortization expense for each of the five succeeding fiscal years related to our intangible assets with a definite life is as follows: Year Non-life Run-off Atrium StarStone Total 2017 $ 9,274 $ (504 ) $ 2,761 $ 11,531 2018 $ 9,524 $ 469 $ 315 $ 10,308 2019 $ 10,178 $ 1,056 $ (380 ) $ 10,854 2020 $ 10,294 $ 1,346 $ (231 ) $ 11,409 2021 $ 9,682 $ 1,620 $ (140 ) $ 11,162

Loans Payable (Tables)

Loans Payable (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Amounts of Loans Payable Outstanding, and Accrued Interest	Under these facilities, loans payable as of December 31, 2016 and 2015 were as follows: Facility Origination Date Term 2016 2015 EGL Revolving Credit Facility September 16, 2014 5 years $ 535,103 $ 505,750 Sussex Facility December 24, 2014 4 years 63,500 94,000 EGL Term Loan Facility November 18, 2016 3 years 75,000 — Total loans payable $ 673,603 $ 599,750

Noncontrolling Interests (Table

Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2016
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 for the years ended December 31, 2016 and 2015 : 2016 2015 Balance at beginning of year $ 417,663 $ 374,619 Capital contributions — 15,728 Dividends paid — (16,128 ) Net earnings (loss) attributable to RNCI 40,639 (8,797 ) Accumulated other comprehensive income (loss) attributable to RNCI 651 (745 ) Transfer from noncontrolling interest — 15,801 Change in redemption value of RNCI (4,431 ) 37,185 Balance at end of year $ 454,522 $ 417,663

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Comparison of Basic and Diluted Earnings per Share	The following table sets forth the computation of basic and diluted earnings per share for the years ended December 31, 2016 , 2015 and 2014 : 2016 2015 2014 Numerator: Net earnings from continuing operations $ 252,844 $ 222,322 $ 208,210 Net earnings (losses) from discontinuing operations 11,963 (2,031 ) 5,539 Net earnings attributable to Enstar Group Limited $ 264,807 $ 220,291 $ 213,749 Denominator: Weighted-average ordinary shares outstanding — basic 19,299,426 19,252,072 18,409,069 Effect of dilutive securities: Restricted shares 31,434 63,900 57,184 Restricted share units 16,994 12,901 15,986 Warrants 99,387 78,883 58,957 Preferred shares — — 136,934 Weighted-average ordinary shares outstanding — diluted 19,447,241 19,407,756 18,678,130 Earnings per share attributable to Enstar Group Limited: Basic: Net earnings from continuing operations $ 13.10 $ 11.55 $ 11.31 Net earnings (loss) from discontinuing operations 0.62 (0.11 ) 0.30 Net earnings per ordinary share $ 13.72 $ 11.44 $ 11.61 Diluted: Net earnings from continuing operations $ 13.00 $ 11.46 $ 11.15 Net earnings (loss) from discontinuing operations 0.62 (0.11 ) 0.29 Net earnings per ordinary share $ 13.62 $ 11.35 $ 11.44

Share-Based Compensation and 53

Share-Based Compensation and Pensions (Tables)	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Restricted Shares and Restricted Share Units	The following ta ble summarizes the activity related to restricted shares and restricted share awards during 2016 : Number of Shares Weighted- Average Share Price of Award Nonvested — January 1 96,055 $ 150.04 Granted 44,165 182.98 Vested (44,925 ) 101.48 Forfeited (16,303 ) 141.09 Nonvested — December 31 78,992 165.94
Summary of SARs Activity	The following t able summarizes the activity related to SARs during 2016: Number of SARs Weighted- Average Exercise Price of SARs Weighted Average Expected Term (in years) Aggregate Intrinsic Value (1) Balance, beginning of year 1,160,828 $ 140.51 Exercised (92,458 ) 139.88 Forfeited (127,202 ) 139.58 Balance, end of year 941,168 140.70 1.94 $ 53,644 (1) The aggregate intrinsic value is calculated as the pre-tax difference between the exercise price of the underlying share awards and the closing price per share of our ordinary shares of $197.70 on December 31, 2016 .
Assumptions Used to Estimate Fair Value of SARs Using Black-Scholes Option Valuation Model	The following table sets forth the assumptions used to estimate the fair value of the SARs using the Black-Scholes option valuation model as at December 31, 2016 and 2015 : 2016 2015 2014 Weighted-average fair value per SAR $ 62.39 $ 29.02 $ 37.63 Weighted-average volatility 19.82 % 22.08 % 21.24 % Weighted-average risk-free interest rate 1.12 % 1.29 % 0.81 % Dividend yield 0.00 % 0.00 % 0.00 %

Taxation (Tables)

Taxation (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Earnings before Income Taxes	The following table presents earnings before income taxes by jurisdiction from continuing operations : 2016 2015 2014 Domestic (Bermuda) $ 191,647 $ 61,695 $ 154,453 Foreign 135,677 163,327 72,845 Total earnings before income tax on continuing operations $ 327,324 $ 225,022 $ 227,298
Tax Expense for Income Taxes	The following table presents our current and deferred income tax expense (benefit) from continuing operations by jurisdiction: 2016 2015 2014 Current: Domestic (Bermuda) $ — $ — $ — Foreign 21,485 30,028 38,814 21,485 30,028 38,814 Deferred: Domestic (Bermuda) — — — Foreign 13,389 (17,378 ) (33,213 ) 13,389 (17,378 ) (33,213 ) Total tax expense on continuing operations $ 34,874 $ 12,650 $ 5,601
Reconciliation of Earnings before Income Taxes Computed by Applying Effective Rate	The actual income tax rate differs from the amount computed by applying the effective rate of 0% under Bermuda law to earnings from continuing operations before income taxes as shown in the following reconciliation: 2016 2015 2014 Earnings before income tax $ 327,324 $ 225,022 $ 227,298 Bermuda income taxes at statutory rate 0.0 % 0.0 % 0.0 % Foreign income tax rate differential 8.8 % 17.6 % 11.3 % Change in unrecognized tax benefits — % — % (1.0 )% Benefit of loss carryovers — % — % (1.3 )% Change in valuation allowance (0.1 )% (10.5 )% (13.2 )% Investment write-off — % — % 1.9 % Foreign currency translation — % (0.3 )% 0.8 % Other 2.0 % (1.2 )% 4.0 % Effective tax rate 10.7 % 5.6 % 2.5 %
Components of Deferred Tax Assets and Deferred Tax Liabilities	Significant components of the deferred tax assets and deferred tax liabilities related to our continuing operations were as follows: As of December 31, 2016 2015 Deferred tax assets: Net operating loss carryforwards $ 262,271 $ 259,851 Tax credits and other carryforwards 7,487 6,354 Insurance reserves 19,265 29,682 Unearned premiums 8,760 6,821 Lloyd's underwriting losses taxable in future periods 6,581 17,768 Provisions for bad debt 16,018 17,694 Other deferred tax assets 7,946 3,532 Gross deferred tax assets 328,328 341,702 Valuation allowance (290,861 ) (291,280 ) Deferred tax assets 37,467 50,422 Deferred tax liabilities: Unrealized gains on investments (12,804 ) (10,567 ) Intangible assets (20,615 ) (20,895 ) Other deferred tax liabilities (21,030 ) (22,044 ) Deferred tax liabilities (54,449 ) (53,506 ) Net deferred tax liability $ (16,982 ) $ (3,084 )
Summary of Operating Loss Carryforwards	As of December 31, 2016 , we had net operating loss carryforwards that could be available to offset future taxable income, as follows: Tax Jurisdiction Loss Carryforwards Tax effect Expiration Operating and Capital Loss Carryforwards: United States - Net operating loss $ 571,235 $ 193,670 2021-2033 United States - Capital loss 11,820 4,905 2021-2026 United Kingdom 280,707 57,381 None Other 30,098 6,152 None Tax Credits: United States alternative minimum tax $ 7,374 None
Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: 2016 2015 2014 Balance, beginning of year $ — $ — $ 2,249 Gross increases — tax positions related to prior years — — — Gross decreases — tax positions related to prior years — — — Lapse of statute of limitations — — (2,249 ) Balance, end of year $ — $ — $ —
Summary of Income Tax Examinations	Listed below are the tax years that remain subject to examination by a major tax jurisdiction as of December 31, 2016 : Major Tax Jurisdiction Open Tax Years United States 2013-2015 United Kingdom 2013-2015 Australia 2011-2015

Dividend Restrictions and Sta55

Dividend Restrictions and Statutory Financial Information (Tables)	12 Months Ended
	Dec. 31, 2016
Insurance [Abstract]
Summary of Statutory Capital and Surplus	The statutory capital and surplus amounts for the years ended December 31, 2016 and 2015 and statutory net income amounts for the years ended December 31, 2016 , 2015 and 2014 for our insurance and reinsurance subsidiaries based in Bermuda, the United Kingdom, Australia, the United States and Continental Europe were as follows: Statutory Capital and Surplus Required Actual Statutory Income 2016 2015 2016 2015 2016 2015 2014 Bermuda $ 622,183 $ 510,773 $ 2,131,308 $ 1,767,172 $ 339,548 $ 147,883 $ 41,750 U.K. $ 532,132 $ 61,819 $ 805,170 $ 629,208 $ 131,619 $ 113,296 $ 107,030 U.S. $ 209,283 $ 147,538 $ 662,942 $ 756,543 $ (1,439 ) $ 14,964 $ 91,576 Europe $ 240,107 $ 44,126 $ 286,039 $ 211,458 $ 31,075 $ 1,856 $ 11,959

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments on Non-Cancellable Leases	The following is a schedule of future minimum rental payments on non-cancelable leases as of December 31, 2016 : 2017 $ 10,022 2018 9,510 2019 7,752 2020 6,183 2021 4,147 2022 and beyond 8,170 $ 45,784

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Summary of Operations by Segment	The following tables set forth selected and consolidated statement of earnings results by segment for the years ended December 31, 2016 , 2015 , 2014 : 2016 Non-life Run-off Atrium StarStone Life and Annuities Eliminations Consolidated INCOME Net premiums earned $ 16,755 $ 124,416 $ 676,608 $ 5,735 $ — $ 823,514 Fees and commission income 25,324 18,189 5,102 — (9,251 ) 39,364 Net investment income 143,783 2,940 22,221 20,043 (3,524 ) 185,463 Net realized and unrealized gains (losses) 77,689 (601 ) 5,728 (4,998 ) — 77,818 Other income 4,003 206 1,780 353 (1,506 ) 4,836 267,554 145,150 711,439 21,133 (14,281 ) 1,130,995 EXPENSES Net incurred losses and LAE (285,881 ) 58,387 401,593 — — 174,099 Life and annuity policy benefits — — — (2,038 ) — (2,038 ) Acquisition costs 4,198 44,670 138,822 612 (1,733 ) 186,569 General and administrative expenses 275,199 25,132 125,279 7,148 (9,024 ) 423,734 Interest expense 22,863 198 47 1,058 (3,524 ) 20,642 Net foreign exchange losses (gains) (1,678 ) 3,310 (754 ) (213 ) — 665 14,701 131,697 664,987 6,567 (14,281 ) 803,671 EARNINGS BEFORE INCOME TAXES 252,853 13,453 46,452 14,566 — 327,324 INCOME TAXES (28,577 ) (2,573 ) (3,693 ) (31 ) — (34,874 ) NET EARNINGS FROM CONTINUING OPERATIONS 224,276 10,880 42,759 14,535 — 292,450 NET EARNINGS FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE — — — 11,963 — 11,963 Less: Net earnings attributable to noncontrolling interest (17,600 ) (4,464 ) (17,542 ) — — (39,606 ) NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED $ 206,676 $ 6,416 $ 25,217 $ 26,498 $ — $ 264,807 2015 Non-life Run-off Atrium StarStone Life and Annuities Eliminations Consolidated INCOME Net premiums earned $ 44,369 $ 134,675 $ 573,146 $ 1,554 $ — $ 753,744 Fees and commission income 21,366 28,352 — — (10,371 ) 39,347 Net investment income 84,185 2,225 15,937 21,137 (920 ) 122,564 Net realized and unrealized gains (losses) (31,193 ) 252 (9,784 ) (798 ) — (41,523 ) Other income 29,293 359 676 — — 30,328 148,020 165,863 579,975 21,893 (11,291 ) 904,460 EXPENSES Net incurred losses and LAE (270,830 ) 47,479 327,684 — — 104,333 Life and annuity policy benefits — — — (546 ) — (546 ) Acquisition costs 8,860 45,509 109,347 — — 163,716 General and administrative expenses 238,989 31,610 126,132 2,799 (10,371 ) 389,159 Interest expense 14,565 4,264 6 1,488 (920 ) 19,403 Net foreign exchange losses (gains) 4,372 213 (480 ) (732 ) — 3,373 (4,044 ) 129,075 562,689 3,009 (11,291 ) 679,438 EARNINGS BEFORE INCOME TAXES 152,064 36,788 17,286 18,884 — 225,022 INCOME TAXES (12,570 ) (5,968 ) 5,888 — — (12,650 ) NET EARNINGS FROM CONTINUING OPERATIONS 139,494 30,820 23,174 18,884 — 212,372 NET LOSS FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE — — — (2,031 ) — (2,031 ) Less: Net losses (earnings) attributable to noncontrolling interest 33,722 (14,262 ) (9,510 ) — — 9,950 NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED $ 173,216 $ 16,558 $ 13,664 $ 16,853 $ — $ 220,291 2014 Non-life Atrium StarStone Life and Eliminations Consolidated INCOME Net premiums earned $ 31,168 $ 135,945 $ 373,633 $ 2,245 $ — $ 542,991 Fees and commission income 19,342 26,176 — 32 (10,631 ) 34,919 Net investment income 57,899 1,748 5,321 1,056 — 66,024 Net realized and unrealized gains 48,030 41 2,136 1,784 — 51,991 Other income 13,310 223 616 — — 14,149 169,749 164,133 381,706 5,117 (10,631 ) 710,074 EXPENSES Net incurred losses and LAE (264,711 ) 55,428 218,429 — — 9,146 Life and annuity policy benefits — — — 84 — 84 Acquisition costs 8,393 43,417 65,734 (2 ) — 117,542 General and administrative expenses 198,063 34,921 113,344 1,423 (10,631 ) 337,120 Interest expense 7,493 5,429 — — — 12,922 Net foreign exchange losses (gains) 8,015 (1,559 ) 945 (1,439 ) — 5,962 (42,747 ) 137,636 398,452 66 (10,631 ) 482,776 EARNINGS (LOSS) BEFORE INCOME TAXES 212,496 26,497 (16,746 ) 5,051 — 227,298 INCOME TAXES 622 (5,092 ) (1,130 ) (1 ) — (5,601 ) NET EARNINGS (LOSS) FROM CONTINUING OPERATIONS 213,118 21,405 (17,876 ) 5,050 — 221,697 NET EARNINGS FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE — — — 5,539 — 5,539 Less: Net losses (earnings) attributable to noncontrolling interest (9,836 ) (10,974 ) 7,323 — — (13,487 ) NET EARNINGS (LOSS) ATTRIBUTABLE TO ENSTAR GROUP LIMITED $ 203,282 $ 10,431 $ (10,553 ) $ 10,589 $ — $ 213,749
Schedule of Revenue from External Customers	The following table summarizes our gross premiums written for the year ended December 31, 2016 by each of our operating segments by geographic area. Geographic distribution in subsequent years is subject to variation based upon market conditions and business strategies. Non-life Run-off Atrium StarStone Life and Annuities Total Total % Total % Total % Total % Total % (In thousands of U.S. dollars, except percentages) United States $ 17,316 100.0 % $ 79,433 55.5 % $ 520,045 60.8 % $ — — % $ 616,794 60.3 % United Kingdom — — % 9,200 6.4 % 98,067 11.5 % 899 12.6 % 108,166 10.6 % Europe — — % 8,797 6.1 % 135,971 15.9 % 6,256 87.4 % 151,024 14.8 % Asia — — % 6,766 4.7 % 43,200 5.1 % — — % 49,966 4.9 % Rest of World — — % 38,974 27.3 % 57,416 6.7 % — — % 96,390 9.4 % Total $ 17,316 100.0 % $ 143,170 100.0 % $ 854,699 100.0 % $ 7,155 100.0 % $ 1,022,340 100.0 %
Summary of Company's Assets by Segment	Invested assets are managed on a subsidiary by subsidiary basis, and investment income and realized and unrealized gains on investments are recognized in each segment as earned. Our total assets as at December 31, 2016 and 2015 by segment were as follows (the elimination items include the elimination of intersegment assets): 2016 2015 Total assets: Non-life Run-off $ 8,297,103 $ 7,602,594 Atrium 563,754 559,377 StarStone 2,968,316 2,780,462 Life and annuities 1,644,013 1,695,994 Less: Eliminations (607,442 ) (865,893 ) $ 12,865,744 $ 11,772,534

Unaudited Condensed Quarterly58

Unaudited Condensed Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Unaudited Condensed Quarterly Financial Data	December 31, September 30, June 30, March 31, 2016 2015 2016 2015 2016 2015 2016 2015 INCOME Net premiums earned $ 216,188 $ 178,009 $ 205,730 $ 209,971 $ 208,709 $ 189,344 $ 192,887 $ 176,420 Fees and commission income 13,266 7,450 9,187 9,708 10,487 10,125 6,424 12,064 Net investment income 42,229 44,265 48,022 31,640 44,932 25,265 50,280 21,394 Net realized and unrealized gains (losses) (61,570 ) (56,705 ) 66,608 (15,835 ) 34,503 (8,296 ) 38,277 39,313 Other income (1,277 ) 12,648 414 2,370 3,289 11,833 2,410 3,477 208,836 185,667 329,961 237,854 301,920 228,271 290,278 252,668 EXPENSES Net incurred losses and loss adjustment expenses 1,321 (64,062 ) (6,902 ) 32,359 96,462 65,900 83,218 70,136 Life and annuity policy benefits (2,265 ) (1,808 ) 1,682 401 (1,613 ) 407 158 454 Acquisition costs 47,619 53,666 50,074 44,445 43,847 33,781 45,029 31,824 General and administrative expenses 123,497 106,754 103,097 96,818 104,206 90,837 92,934 94,750 Interest expense 4,796 5,368 5,027 5,156 5,421 4,876 5,398 4,003 Net foreign exchange losses (gains) (1,527 ) 7,004 2,276 (841 ) (1,856 ) 2,297 1,772 (5,087 ) 173,441 106,922 155,254 178,338 246,467 198,098 228,509 196,080 EARNINGS BEFORE INCOME TAXES 35,395 78,745 174,707 59,516 55,453 30,173 61,769 56,588 INCOME TAXES (11,228 ) 15,794 (8,227 ) (12,684 ) (8,050 ) (8,087 ) (7,369 ) (7,673 ) NET EARNINGS FROM CONTINUING OPERATIONS 24,167 94,539 166,480 46,832 47,403 22,086 54,400 48,915 NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE 5,483 (1,898 ) 3,897 (831 ) 2,378 (3,879 ) 205 4,577 NET EARNINGS 29,650 92,641 170,377 46,001 49,781 18,207 54,605 53,492 Less: Net losses (earnings) attributable to noncontrolling interest (7,005 ) 19,216 (14,329 ) 3,041 (9,187 ) (3,662 ) (9,085 ) (8,645 ) NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED $ 22,645 $ 111,857 $ 156,048 $ 49,042 $ 40,594 $ 14,545 $ 45,520 $ 44,847 EARNINGS PER SHARE —BASIC: Net earnings from continuing operations $ 0.91 $ 5.91 $ 7.86 $ 2.57 $ 1.99 $ 0.99 $ 2.34 $ 2.04 Net earnings (loss) from discontinuing operations $ 0.26 $ (0.11 ) $ 0.23 $ (0.02 ) $ 0.11 $ (0.23 ) $ 0.02 $ 0.29 Net earnings per ordinary share attributable to Enstar Group Limited shareholders $ 1.17 $ 5.80 $ 8.09 $ 2.55 $ 2.10 $ 0.76 $ 2.36 $ 2.33 EARNINGS PER SHARE — DILUTED: Net earnings from continuing operations $ 0.90 $ 5.86 $ 7.79 $ 2.55 $ 1.98 $ 0.98 $ 2.33 $ 2.03 Net earnings (loss) from discontinuing operations $ 0.26 $ (0.11 ) $ 0.23 $ (0.02 ) $ 0.11 $ (0.23 ) $ 0.02 $ 0.29 Net earnings per ordinary share attributable to Enstar Group Limited shareholders $ 1.16 $ 5.75 $ 8.02 $ 2.53 $ 2.09 $ 0.75 $ 2.35 $ 2.32

Description of Business - Addit

Description of Business - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016Segment
Segment Reporting Information [Line Items]
Number of segments	4
Atrium
Segment Reporting Information [Line Items]
Syndicate underwriting capacity percentage	25.00%

Significant Accounting Polici60

Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2016compensation_type
Accounting Policies [Abstract]
Number of types of compensation	3

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) $ / shares in Units, € in Millions

Dec. 30, 2016USD ($)

May 05, 2016USD ($)

Nov. 13, 2015USD ($)

Nov. 13, 2015EUR (€)

May 05, 2015USD ($)Companyinstallment

Jan. 27, 2015USD ($)

Jun. 10, 2014shares

May 08, 2014USD ($)member

Apr. 01, 2014USD ($)insurance_vehicle$ / sharesshares

Jul. 08, 2013USD ($)$ / shares

Dec. 31, 2016USD ($)$ / shares

Dec. 31, 2015USD ($)$ / shares

Dec. 31, 2014USD ($)

May 07, 2014

Mar. 31, 2014$ / shares

Business Acquisition [Line Items]

Common shares, par value (dollars per share) | $ / shares

$ 1

$ 1

Goodwill recognized

$ 73,071,000

$ 73,071,000

$ 73,071,000

Voting ordinary shares

Business Acquisition [Line Items]

Common shares, par value (dollars per share) | $ / shares

$ 1

$ 1

$ 1

Non-life Run-off

Business Acquisition [Line Items]

Goodwill recognized

$ 21,200,000

$ 21,200,000

Dowling

Business Acquisition [Line Items]

Investment in entities

$ 15,400,000

StarStone Holdings

Business Acquisition [Line Items]

Number of members appointed to board of directors by parent | member

3

StarStone Holdings | Trident

Business Acquisition [Line Items]

Number of members appointed to board of directors by noncontrolling owners | member

2

Wilton Re | CPPIB and Management of Wilton Re

Business Acquisition [Line Items]

Ownership interest held by parent

100.00%

100.00%

StarStone Holdings | Kenmare

Business Acquisition [Line Items]

Ownership interest held by parent

59.00%

60.00%

60.00%

StarStone Holdings | Kenmare | Trident

Business Acquisition [Line Items]

Ownership interest held by noncontrolling owners

39.30%

40.00%

40.00%

StarStone Holdings | Kenmare | Dowling

Business Acquisition [Line Items]

Ownership interest held by noncontrolling owners

1.70%

Northshore | Kenmare

Business Acquisition [Line Items]

Ownership interest held by parent

59.00%

60.00%

Northshore | Kenmare | Trident

Business Acquisition [Line Items]

Ownership interest held by noncontrolling owners

39.30%

40.00%

Northshore | Kenmare | Dowling

Business Acquisition [Line Items]

Ownership interest held by noncontrolling owners

1.70%

Dana Companies

Business Acquisition [Line Items]

Acquisition consideration

$ 88,500,000

Net earnings (losses) of acquiree since acquisition date

$ 0

Goodwill recognized

$ 0

Nationale Suisse Assurance S.A.

Business Acquisition [Line Items]

Acquisition consideration

$ 35,225,000

€ 32.8

Net earnings (losses) of acquiree since acquisition date

(100,000)

Earned premiums of acquiree since acquisition date

0

Net incurred losses and LAE of acquiree since acquisition date

0

Goodwill recognized

$ 0

Wilton Re

Business Acquisition [Line Items]

Acquisition consideration

$ 173,058,000

Net earnings (losses) of acquiree since acquisition date

16,500,000

Number of payment installments | installment

2

Cash payments for acquisition

$ 83,900,000

$ 89,100,000

Number of companies acquired | Company

2

Goodwill recognized

$ 0

Sussex Insurance Company

Business Acquisition [Line Items]

Acquisition consideration

$ 218,000,000

$ 397,700,000

Cash payments for acquisition

41,600,000

Percentage of consideration financed through bank loan facility

50.00%

Percentage of consideration paid from cash on hand

50.00%

Fair value adjustment to net unearned premiums acquired

$ (34,600,000)

$ (11,100,000)

Unamortized unearned premium fair value adjustment

2,700,000

Number of wholly-owned insurance vehicles | insurance_vehicle

6

Acquisition consideration including noncontrolling interest consideration

$ 656,100,000

$ 646,000,000

Acquisition purchase price (dollars per share) | $ / shares

$ 136.31

$ 132.448

$ 136.31

Average closing price of voting ordinary shares prior to trading period (days)

20 days

Acquisition related transaction expenses

$ 3,600,000

Goodwill recognized

$ 0

13,000,000

Indefinite-lived intangible assets recognized

23,900,000

Finite-lived intangible assets recognized

$ 20,000,000

Sussex Insurance Company | Voting ordinary shares | Ordinary Shares

Business Acquisition [Line Items]

Shares issued (in shares) | shares

1,898,326

Sussex Insurance Company | Non-voting preferred stock | Preferred Stock

Business Acquisition [Line Items]

Shares issued (in shares) | shares

714,015

Sussex Insurance Company | Trident

Business Acquisition [Line Items]

Acquisition consideration - noncontrolling interest

$ 258,400,000

Transaction costs - noncontrolling interest

$ 2,400,000

Sussex Insurance Company | First Reserve | Voting ordinary shares | Ordinary Shares | Affiliated entity

Business Acquisition [Line Items]

Shares issued (in shares) | shares

1,501,211

Sussex Insurance Company | First Reserve | Non-voting preferred stock | Preferred Stock | Affiliated entity

Business Acquisition [Line Items]

Shares issued (in shares) | shares

714,015

Sussex Insurance Company | First Reserve | Series E non-voting convertible ordinary shares | Affiliated entity

Business Acquisition [Line Items]

Conversion of stock, shares issued (in shares) | shares

714,015

Sussex Insurance Company | Corsair | Voting ordinary shares | Ordinary Shares | Affiliated entity

Business Acquisition [Line Items]

Shares issued (in shares) | shares

397,115

Sussex Insurance Company | Non-life Run-off

Business Acquisition [Line Items]

Net earnings (losses) of acquiree since acquisition date

(42,400,000)

Earned premiums of acquiree since acquisition date

43,200,000

Net incurred losses and LAE of acquiree since acquisition date

$ 44,400,000

Sussex Insurance Company | Acquisition costs

Business Acquisition [Line Items]

Amortization of fair value adjustment to net unearned premiums acquired

16,100,000

Sussex Insurance Company | Net premiums earned

Business Acquisition [Line Items]

Amortization of fair value adjustment to net unearned premiums acquired

$ 15,700,000

Acquisitions - Purchase Price a

Acquisitions - Purchase Price and Fair Value of Assets Acquired (Detail) $ in Thousands, € in Millions	Dec. 30, 2016USD ($)	Nov. 13, 2015USD ($)	Nov. 13, 2015EUR (€)	May 05, 2015USD ($)	Jan. 27, 2015USD ($)	Apr. 01, 2014USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Business Acquisition [Line Items]
Excess of purchase price over fair value of net assets acquired							$ 73,071	$ 73,071	$ 73,071
Dana Companies
Business Acquisition [Line Items]
Purchase price	$ 88,500
Net assets acquired at fair value	88,500
Excess of purchase price over fair value of net assets acquired	$ 0
Nationale Suisse Assurance S.A.
Business Acquisition [Line Items]
Purchase price		$ 35,225	€ 32.8
Net assets acquired at fair value		35,225
Excess of purchase price over fair value of net assets acquired		$ 0
Wilton Re
Business Acquisition [Line Items]
Purchase price				$ 173,058
Net assets acquired at fair value				173,058
Excess of purchase price over fair value of net assets acquired				$ 0
Sussex Insurance Company
Business Acquisition [Line Items]
Purchase price					$ 218,000	$ 397,700
Net assets acquired at fair value					218,000
Excess of purchase price over fair value of net assets acquired					$ 0	13,000
StarStone
Business Acquisition [Line Items]
Purchase price						656,088
Net assets acquired at fair value						643,088
Excess of purchase price over fair value of net assets acquired						$ 13,000

Acquisitions - Summary of Estim

Acquisitions - Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed as of Date of Acquisition (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 30, 2016	Dec. 31, 2015	Nov. 13, 2015	May 05, 2015	Jan. 27, 2015	Dec. 31, 2014	Apr. 01, 2014
LIABILITIES
Goodwill	$ 73,071		$ 73,071				$ 73,071
Non-life Run-off Segment
LIABILITIES
Goodwill	21,200		21,200
StarStone Segment
LIABILITIES
Goodwill	$ 13,000		$ 13,000
Dana Companies
LIABILITIES
NET ASSETS ACQUIRED AT FAIR VALUE		$ 88,500
Goodwill		0
Dana Companies | Non-life Run-off Segment
ASSETS
Other investments, at fair value		46,589
Total investments		130,725
Cash and cash equivalents		58,430
Restricted cash and cash equivalents		1,692
Reinsurance balances recoverable		133,032
Other assets		5,383
TOTAL ASSETS		329,262
LIABILITIES
Other liabilities - Asbestos related		220,496
Other liabilities		20,266
TOTAL LIABILITIES		240,762
NET ASSETS ACQUIRED AT FAIR VALUE		88,500
Dana Companies | Non-life Run-off Segment | Short-term investments
ASSETS
Trading, at fair value		22,747
Dana Companies | Non-life Run-off Segment | Fixed maturities
ASSETS
Trading, at fair value		$ 61,389
Nationale Suisse Assurance S.A.
ASSETS
Other investments, at fair value				$ 1,339
Total investments				144,676
Cash and cash equivalents				64,709
Reinsurance balances recoverable — reserves				4,343
Reinsurance balances recoverable — paids				12,151
Prepaid reinsurance premiums				3,213
Other assets				5,395
TOTAL ASSETS				234,487
LIABILITIES
Losses and LAE				173,209
Funds withheld				473
Insurance and reinsurance balances payable				6,991
Unearned premium				5,969
Other liabilities				12,620
TOTAL LIABILITIES				199,262
NET ASSETS ACQUIRED AT FAIR VALUE				35,225
Goodwill				0
Nationale Suisse Assurance S.A. | Short-term investments
ASSETS
Trading, at fair value				8,644
Available-for-sale, at fair value				6,687
Nationale Suisse Assurance S.A. | Fixed maturities
ASSETS
Trading, at fair value				31,350
Available-for-sale, at fair value				96,656
Nationale Suisse Assurance S.A. | Life and Annuities Segment
ASSETS
Other investments, at fair value				0
Total investments				103,343
Cash and cash equivalents				25,258
Reinsurance balances recoverable — reserves				302
Reinsurance balances recoverable — paids				1,320
Prepaid reinsurance premiums				0
Other assets				2,298
TOTAL ASSETS				132,521
LIABILITIES
Losses and LAE				117,188
Funds withheld				0
Insurance and reinsurance balances payable				779
Unearned premium				0
Other liabilities				2,875
TOTAL LIABILITIES				120,842
NET ASSETS ACQUIRED AT FAIR VALUE				11,679
Nationale Suisse Assurance S.A. | Life and Annuities Segment | Short-term investments
ASSETS
Trading, at fair value				0
Available-for-sale, at fair value				6,687
Nationale Suisse Assurance S.A. | Life and Annuities Segment | Fixed maturities
ASSETS
Trading, at fair value				0
Available-for-sale, at fair value				96,656
Nationale Suisse Assurance S.A. | Non-life Run-off Segment
ASSETS
Other investments, at fair value				1,339
Total investments				41,333
Cash and cash equivalents				39,451
Reinsurance balances recoverable — reserves				4,041
Reinsurance balances recoverable — paids				10,831
Prepaid reinsurance premiums				3,213
Other assets				3,097
TOTAL ASSETS				101,966
LIABILITIES
Losses and LAE				56,021
Funds withheld				473
Insurance and reinsurance balances payable				6,212
Unearned premium				5,969
Other liabilities				9,745
TOTAL LIABILITIES				78,420
NET ASSETS ACQUIRED AT FAIR VALUE				23,546
Nationale Suisse Assurance S.A. | Non-life Run-off Segment | Short-term investments
ASSETS
Trading, at fair value				8,644
Available-for-sale, at fair value				0
Nationale Suisse Assurance S.A. | Non-life Run-off Segment | Fixed maturities
ASSETS
Trading, at fair value				31,350
Available-for-sale, at fair value				$ 0
Wilton Re
ASSETS
Other investments, at fair value					$ 142,182
Cash and cash equivalents					5,043
Other assets					26,376
TOTAL ASSETS					173,601
LIABILITIES
TOTAL LIABILITIES					543
NET ASSETS ACQUIRED AT FAIR VALUE					173,058
Goodwill					$ 0
Sussex Insurance Company
ASSETS
Equities, trading, at fair value						$ 31,439
Total investments						639,975
Cash and cash equivalents						358,458
Restricted cash and cash equivalents						15,279
Accrued interest receivable						3,984
Premiums receivable						37,190
Reinsurance balances recoverable						483,816
Prepaid reinsurance premiums						28,751
Other assets						43,939
TOTAL ASSETS						1,611,392
LIABILITIES
Losses and LAE						1,257,205
Funds withheld						42,090
Insurance and reinsurance balances payable						3,030
Unearned premium						79,293
Other liabilities						11,774
TOTAL LIABILITIES						1,393,392
NET ASSETS ACQUIRED AT FAIR VALUE						218,000
Goodwill						0		$ 13,000
Sussex Insurance Company | Short-term investments
ASSETS
Trading, at fair value						85,309
Sussex Insurance Company | Fixed maturities
ASSETS
Trading, at fair value						$ 523,227
StarStone
ASSETS
Other investments, at fair value								2,068
Total investments								1,167,381
Cash and cash equivalents								339,608
Restricted cash and cash equivalents								22,779
Premiums receivable								321,350
Reinsurance balances recoverable — reserves								362,799
Reinsurance balances recoverable — paids								41,222
Prepaid reinsurance premiums								169,442
Intangible assets								43,900
Other assets								37,621
TOTAL ASSETS								2,506,102
LIABILITIES
Losses and LAE								1,264,246
Insurance and reinsurance balances payable								183,444
Unearned premium								392,962
Other liabilities								22,362
TOTAL LIABILITIES								1,863,014
NET ASSETS ACQUIRED AT FAIR VALUE								643,088
Goodwill								13,000
ACQUISITION DATE FAIR VALUE								656,088
StarStone | Short-term investments
ASSETS
Trading, at fair value								99,313
StarStone | Fixed maturities
ASSETS
Trading, at fair value								1,066,000
StarStone | Non-life Run-off Segment
ASSETS
Other investments, at fair value								0
Total investments								355,123
Cash and cash equivalents								127,890
Restricted cash and cash equivalents								0
Premiums receivable								0
Reinsurance balances recoverable — reserves								152,057
Reinsurance balances recoverable — paids								20,100
Prepaid reinsurance premiums								25,221
Intangible assets								0
Other assets								0
TOTAL ASSETS								680,391
LIABILITIES
Losses and LAE								588,822
Insurance and reinsurance balances payable								42,447
Unearned premium								49,122
Other liabilities								0
TOTAL LIABILITIES								680,391
NET ASSETS ACQUIRED AT FAIR VALUE								0
Goodwill								0
ACQUISITION DATE FAIR VALUE								0
StarStone | Non-life Run-off Segment | Short-term investments
ASSETS
Trading, at fair value								25,888
StarStone | Non-life Run-off Segment | Fixed maturities
ASSETS
Trading, at fair value								329,235
StarStone | StarStone Segment
ASSETS
Other investments, at fair value								2,068
Total investments								812,258
Cash and cash equivalents								211,718
Restricted cash and cash equivalents								22,779
Premiums receivable								321,350
Reinsurance balances recoverable — reserves								210,742
Reinsurance balances recoverable — paids								21,122
Prepaid reinsurance premiums								144,221
Intangible assets								43,900
Other assets								37,621
TOTAL ASSETS								1,825,711
LIABILITIES
Losses and LAE								675,424
Insurance and reinsurance balances payable								140,997
Unearned premium								343,840
Other liabilities								22,362
TOTAL LIABILITIES								1,182,623
NET ASSETS ACQUIRED AT FAIR VALUE								643,088
Goodwill								13,000
ACQUISITION DATE FAIR VALUE								656,088
StarStone | StarStone Segment | Short-term investments
ASSETS
Trading, at fair value								73,425
StarStone | StarStone Segment | Fixed maturities
ASSETS
Trading, at fair value								$ 736,765

Acquisitions - Summary of Intan

Acquisitions - Summary of Intangible Assets Recorded in Connection with Acquisition (Detail) - StarStone $ in Thousands	Apr. 01, 2014USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets as of the acquisition date	$ 43,900
Syndicate capacity
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets as of the acquisition date, indefinite-lived	4,000
U.S. insurance licenses
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets as of the acquisition date, indefinite-lived	19,900
Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets as of the acquisition date, finite-lived	$ 15,000
Intangible assets as of the acquisition date, economic useful life	4 years
Brand
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets as of the acquisition date, finite-lived	$ 5,000
Intangible assets as of the acquisition date, economic useful life	6 years

Acquisitions - Pro Forma Conden

Acquisitions - Pro Forma Condensed Combined Statement of Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income	$ 208,836	$ 329,961	$ 301,920	$ 290,278	$ 185,667	$ 237,854	$ 228,271	$ 252,668	$ 1,130,995	$ 904,460	$ 710,074
Total expenses										(694,119)	(482,838)
Total noncontrolling interest	(7,005)	(14,329)	(9,187)	(9,085)	19,216	3,041	(3,662)	(8,645)	(39,606)	9,950	(13,487)
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED	$ 22,645	$ 156,048	$ 40,594	$ 45,520	$ 111,857	$ 49,042	$ 14,545	$ 44,847	$ 264,807	220,291	213,749
Sussex Insurance Company
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income										29,990	267,939
Total expenses										(39,860)	(360,018)
Total noncontrolling interest										0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED										(9,870)	(92,079)
Alpha
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income										31,884	44,910
Total expenses										(47,026)	(52,103)
Total noncontrolling interest										0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED										(15,142)	(7,193)
Wilton Re
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income										5,793	17,378
Total expenses										(3,628)	(10,884)
Total noncontrolling interest										0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED										2,165	6,494
StarStone
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income											147,193
Total expenses											(145,479)
Total noncontrolling interest											0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED											1,714
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements
Business Acquisition, Pro Forma Information [Abstract]
Total income										981,621	1,025,744
Total expenses										(778,739)	(908,869)
Total noncontrolling interest										9,950	(13,487)
Net earnings (loss)										212,832	103,388
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Income adjustment
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income										9,494	(14,557)
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Expense adjustment
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total expenses										5,894	(3,026)
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Noncontrolling interest adjustment
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total noncontrolling interest										0	0
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Net earnings (loss) adjustment
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED										$ 15,388	(17,583)
StarStone
Business Acquisition, Pro Forma Information [Abstract]
Total income											855,421
Total expenses											(624,647)
Total noncontrolling interest											(14,938)
Net earnings (loss)											215,836
StarStone | Pro forma | Income adjustment
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income											(1,846)
StarStone | Pro forma | Expense adjustment
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total expenses											3,670
StarStone | Pro forma | Noncontrolling interest adjustment
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total noncontrolling interest											(1,451)
StarStone | Pro forma | Net earnings (loss) adjustment
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED											$ 373

Acquisitions - Summary of Pro F

Acquisitions - Summary of Pro Forma Adjustments to Pro Forma Condensed Statement of Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Total income	$ 208,836	$ 329,961	$ 301,920	$ 290,278	$ 185,667	$ 237,854	$ 228,271	$ 252,668	$ 1,130,995	$ 904,460	$ 710,074
Total expenses										(694,119)	(482,838)
Total noncontrolling interest	$ (7,005)	$ (14,329)	$ (9,187)	$ (9,085)	$ 19,216	$ 3,041	$ (3,662)	$ (8,645)	$ (39,606)	9,950	(13,487)
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Reversal of amortization of fair value adjustment
Business Acquisition [Line Items]
Total income										13,344
Total expenses										16,173
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Amortization of fair value adjustments
Business Acquisition [Line Items]
Total income										(3,850)	(14,557)
Total expenses										(451)	(5,417)
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Income adjustment
Business Acquisition [Line Items]
Total income										9,494	(14,557)
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Interest expense adjustment
Business Acquisition [Line Items]
Total expenses										(1,098)	(5,744)
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Income tax adjustment
Business Acquisition [Line Items]
Total expenses										(8,730)	8,135
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Expense adjustment
Business Acquisition [Line Items]
Total expenses										5,894	(3,026)
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Pro forma | Noncontrolling interest adjustment
Business Acquisition [Line Items]
Total noncontrolling interest										$ 0	0
StarStone | Pro forma | Amortization of fair value adjustments
Business Acquisition [Line Items]
Total income											(1,846)
Total expenses											4,816
StarStone | Pro forma | Income adjustment
Business Acquisition [Line Items]
Total income											(1,846)
StarStone | Pro forma | Amortization of fair value adjustment related to acquired losses and LAE liabilities and reinsurance balances recoverable
Business Acquisition [Line Items]
Total expenses											(1,146)
StarStone | Pro forma | Expense adjustment
Business Acquisition [Line Items]
Total expenses											3,670
StarStone | Pro forma | Noncontrolling interest adjustment
Business Acquisition [Line Items]
Total noncontrolling interest											$ (1,451)

Significant New Business (Detai

Significant New Business (Detail) £ in Millions

Feb. 07, 2017USD ($)

Feb. 07, 2017GBP (£)

Jan. 11, 2017USD ($)

Nov. 15, 2016USD ($)

Nov. 15, 2016GBP (£)

Aug. 05, 2016USD ($)

Feb. 17, 2016USD ($)

Sep. 30, 2015USD ($)Agreement

May 27, 2015USD ($)trustAgreement

Jan. 15, 2015USD ($)

Jan. 01, 2014USD ($)

Jan. 01, 2014GBP (£)

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)

Dec. 31, 2014USD ($)

Feb. 07, 2017GBP (£)

Nov. 30, 2015USD ($)

Dec. 31, 2013USD ($)

Guarantor Obligations [Line Items]

Assumed business

$ 1,340,444,000

$ 612,441,000

$ 28,630,000

Cash and cash equivalents

954,871,000

795,245,000

897,674,000

Deferred charge

94,551,000

255,911,000

$ 0

$ 0

Reinsurance premium assumed

82,073,000

$ 92,798,000

Allianz

Guarantor Obligations [Line Items]

Percentage of reinsurance agreements entered

50.00%

RSA | Subsequent event

Guarantor Obligations [Line Items]

Assumed business

$ 1,200,000,000

£ 957

Assumed business, net

1,000,000,000

£ 834

Reinsurance premium receivable

$ 1,000,000,000

£ 799

QBE | Subsequent event

Guarantor Obligations [Line Items]

Assumed business

$ 919,000,000

Assumed business, net

$ 444,000,000

Coca-Cola

Guarantor Obligations [Line Items]

Assumed business

$ 108,800,000

Cash and cash equivalents

101,300,000

Approximate value of additional funds transferred to trust

108,800,000

Coca-Cola | Limited parental guarantee

Guarantor Obligations [Line Items]

Limited parental guarantee obligations, initial amount (up to)

27,000,000

Coca-Cola | Other assets

Guarantor Obligations [Line Items]

Deferred charge

$ 7,500,000

Allianz

Guarantor Obligations [Line Items]

Assumed business

$ 1,100,000,000

Approximate value of additional funds transferred to trust

$ 110,000,000

Percentage of reinsurance agreements entered

50.00%

Reinsurance premium assumed

$ 1,100,000,000

Funds held by reinsured companies

2,200,000,000

Allianz | Limited parental guarantee

Guarantor Obligations [Line Items]

Limited parental guarantee obligations, initial amount (up to)

$ 270,000,000

Shelbourne RITC

Guarantor Obligations [Line Items]

Assumed business

$ 158,000,000

£ 121.5

The Doctors Company and its affiliates | Workers' compensation

Guarantor Obligations [Line Items]

Total assets and liabilities assumed

$ 29,500,000

Sun Life

Guarantor Obligations [Line Items]

Assumed business

$ 128,300,000

Cash and cash equivalents

122,500,000

Deferred charge

5,800,000

Approximate value of additional funds transferred to trust

30,600,000

Limited parental guarantee obligations, initial amount (up to)

$ 36,800,000

Percentage of reinsurance agreements entered

100.00%

Number of agreements entered | Agreement

2

Voya Financial

Guarantor Obligations [Line Items]

Assumed business

$ 572,400,000

Cash and cash equivalents

307,000,000

Deferred charge

265,400,000

Approximate value of additional funds transferred to trust

$ 67,200,000

Limited parental guarantee obligations, initial amount (up to)

$ 58,000,000

Percentage of reinsurance agreements entered

100.00%

Number of agreements entered | Agreement

2

Number of reinsurance collateral trusts | trust

2

Reciprocal of America

Guarantor Obligations [Line Items]

Assumed business

$ 162,100,000

Lloyd's syndicate

Guarantor Obligations [Line Items]

Assumed business

$ 28,100,000

£ 17

Held-For-Sale Business - Financ

Held-For-Sale Business - Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Total assets held for sale	$ 1,244,456				$ 1,269,583				$ 1,244,456	$ 1,269,583
Liabilities:
Total liabilities held for sale	1,150,787				1,189,554				1,150,787	1,189,554
EXPENSES
NET EARNINGS FROM DISCONTINUED OPERATIONS	5,483	$ 3,897	$ 2,378	$ 205	(1,898)	$ (831)	$ (3,879)	$ 4,577	11,963	(2,031)	$ 5,539
Pavonia | Discontinued operations, held-for-sale
Assets:
Fixed maturities, held-to-maturity, at amortized cost	765,554				790,866				765,554	790,866
Equities, trading, at fair value	4,428				4,446				4,428	4,446
Other investments, at fair value	15,114				53,743				15,114	53,743
Cash and cash equivalents	18,018				26,680				18,018	26,680
Restricted cash and cash equivalents	5,202				11,415				5,202	11,415
Deferred tax assets	31,500				31,531				31,500	31,531
Reinsurance balances recoverable	18,029				22,083				18,029	22,083
Other assets	60,229				64,300				60,229	64,300
Total assets held for sale	1,244,456				1,269,583				1,244,456	1,269,583
Liabilities:
Policy benefits for life and annuity contracts	1,144,850				1,178,376				1,144,850	1,178,376
Other liabilities	5,937				11,083				5,937	11,083
Total liabilities held for sale	1,150,787				1,189,459				1,150,787	1,189,459
INCOME
Net premiums earned									69,089	85,327	103,459
Net investment income									38,140	35,404	36,599
Net realized and unrealized gains (losses)									4,263	271	10,628
Other income									1,912	7,690	1,813
Total income									113,404	128,692	152,499
EXPENSES
Life and annuity policy benefits									76,594	97,472	107,962
Acquisition costs									9,836	13,712	15,031
General and administrative expenses									14,416	13,886	17,206
Other expenses									199	486	1,220
Total expenses									101,045	125,556	141,419
EARNINGS (LOSS) BEFORE INCOME TAXES									12,359	3,136	11,080
INCOME TAXES									(396)	(5,167)	(5,541)
NET EARNINGS FROM DISCONTINUED OPERATIONS									11,963	(2,031)	5,539
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Operating activities									(71,521)	(5,893)	(46,386)
Investing activities									56,646	(24,766)	32,641
Financing Activities									0	0	0
Change in cash of businesses held for sale									(14,875)	(30,659)	$ (13,745)
Pavonia | Discontinued operations, held-for-sale | Short-term investments
Assets:
Trading, at fair value	0				2,246				0	2,246
Pavonia | Discontinued operations, held-for-sale | Fixed maturities
Assets:
Trading, at fair value	$ 326,382				$ 262,273				$ 326,382	$ 262,273

Held-For-Sale Business - Additi

Held-For-Sale Business - Additional Information (Details) - Pavonia - Discontinued operations, held-for-sale - USD ($) $ in Millions	Feb. 17, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restricted investments		$ 786	$ 804.2
Cumulative translation adjustment balance in accumulated other comprehensive income (loss)		$ (14.8)
Subsequent event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale of entities, consideration	$ 120

Investments - Fair Values of Fi

Investments - Fair Values of Fixed Maturity Investments, Short-Term Investments and Equities Classified as Trading (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	$ 4,611,160	$ 4,813,625
Equities, trading, at fair value	95,047	111,495
Trading securities	4,706,207	4,925,120
U.S. government and agency
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	840,274	742,918
Non-U.S. government
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	267,363	338,170
Corporate
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	2,387,322	2,564,618
Municipal
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	47,181	22,247
Residential mortgage-backed
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	373,528	381,573
Commercial mortgage-backed
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	217,212	232,847
Asset-backed
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	478,280	531,252
Equity securities | US
Schedule of Trading Securities and Other Trading Assets [Line Items]
Equities, trading, at fair value	95,047	108,793
Equity securities | International
Schedule of Trading Securities and Other Trading Assets [Line Items]
Equities, trading, at fair value	0	2,702
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	362,900	355,400
Senior Secured Debt Securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading securities, debt	$ 90,700	$ 94,400

Investments - Contractual Matur

Investments - Contractual Maturities of Fixed Maturity and Short-term Investments Classified as Trading (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Amortized Cost
One year or less	$ 748,634
More than one year through two years	713,175
More than two years through five years	1,270,909
More than five years through ten years	651,539
More than ten years	186,066
Trading securities, amortized cost	4,646,161
Fair Value
One year or less	739,820
More than one year through two years	708,739
More than two years through five years	1,259,564
More than five years through ten years	648,156
More than ten years	185,861
Trading securities, debt	$ 4,611,160	$ 4,813,625
% of Total Fair Value
One year or less	16.00%
More than one year through two years	15.40%
More than two years through five years	27.30%
More than five years through ten years	14.10%
More than ten years	4.00%
Trading securities, percentage of fair value	100.00%
Residential mortgage-backed
Amortized Cost
Securities without single maturity date	$ 378,516
Fair Value
Securities without single maturity date	373,528
Trading securities, debt	$ 373,528	381,573
% of Total Fair Value
Securities without single maturity date	8.10%
Commercial mortgage-backed
Amortized Cost
Securities without single maturity date	$ 220,727
Fair Value
Securities without single maturity date	217,212
Trading securities, debt	$ 217,212	232,847
% of Total Fair Value
Securities without single maturity date	4.70%
Asset-backed
Amortized Cost
Securities without single maturity date	$ 476,595
Fair Value
Securities without single maturity date	478,280
Trading securities, debt	$ 478,280	$ 531,252
% of Total Fair Value
Securities without single maturity date	10.40%

Investments - Amortized Cost an

Investments - Amortized Cost and Fair Values of Fixed Maturity and Short-Term Investments Classified as Available-for-Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 269,864	$ 308,790
Gross Unrealized Gains	3,435	1,217
Gross Unrealized Losses Non-OTTI	(5,532)	(7,706)
Fair Value	267,767	302,301
U.S. government and agency
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	12,784	25,102
Gross Unrealized Gains	32	80
Gross Unrealized Losses Non-OTTI	(106)	(341)
Fair Value	12,710	24,841
Non-U.S. government
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	86,897	89,631
Gross Unrealized Gains	1,303	42
Gross Unrealized Losses Non-OTTI	(2,777)	(3,889)
Fair Value	85,423	85,784
Corporate
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	159,243	182,773
Gross Unrealized Gains	2,040	1,040
Gross Unrealized Losses Non-OTTI	(2,628)	(3,429)
Fair Value	158,655	180,384
Municipal
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,585	5,959
Gross Unrealized Gains	12	4
Gross Unrealized Losses Non-OTTI	(21)	(36)
Fair Value	6,576	5,927
Residential mortgage-backed
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	488	665
Gross Unrealized Gains	39	51
Gross Unrealized Losses Non-OTTI	0	(1)
Fair Value	527	715
Asset-backed
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,867	4,660
Gross Unrealized Gains	9	0
Gross Unrealized Losses Non-OTTI	0	(10)
Fair Value	$ 3,876	$ 4,650

Investments - Contractual Mat73

Investments - Contractual Maturities of Fixed Maturity and Short-Term Investments Classified as Available-for-Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Amortized Cost
One year or less	$ 48,561
More than one year through two years	62,855
More than two years through five years	72,008
More than five years through ten years	43,889
More than ten years	38,196
Amortized Cost	269,864	$ 308,790
Fair Value
One year or less	46,955
More than one year through two years	61,395
More than two years through five years	70,404
More than five years through ten years	45,173
More than ten years	39,437
Fair Value	$ 267,767	302,301
% of Total Fair Value
One year or less	17.50%
More than one year through two years	22.90%
More than two years through five years	26.30%
More than five years through ten years	16.90%
More than ten years	14.70%
Percentage of Total Fair Value	100.00%
Residential mortgage-backed
Amortized Cost
Securities without single maturity date	$ 488
Amortized Cost	488	665
Fair Value
Securities without single maturity date	527
Fair Value	$ 527	715
% of Total Fair Value
Securities without single maturity date	0.20%
Asset-backed
Amortized Cost
Securities without single maturity date	$ 3,867
Amortized Cost	3,867	4,660
Fair Value
Securities without single maturity date	3,876
Fair Value	$ 3,876	$ 4,650
% of Total Fair Value
Securities without single maturity date	1.50%

Investments - Gross Unrealized

Investments - Gross Unrealized Losses (Detail) $ in Thousands	Dec. 31, 2016USD ($)Security	Dec. 31, 2015USD ($)Security
Fair Value
12 Months or Greater	$ 16,319	$ 78,533
Less Than 12 Months	86,265	157,430
Total	102,584	235,963
Gross Unrealized Losses
12 Months or Greater	(3,594)	(5,040)
Less Than 12 Months	(1,938)	(2,666)
Total	$ (5,532)	$ (7,706)
Number of securities classified as available-for-sale in an unrealized loss position | Security	156	332
Number of securities classified as available-for-sale in an unrealized loss position for twelve months or longer | Security	41	124
U.S. government and agency
Fair Value
12 Months or Greater	$ 0	$ 523
Less Than 12 Months	10,743	21,694
Total	10,743	22,217
Gross Unrealized Losses
12 Months or Greater	0	(2)
Less Than 12 Months	(106)	(339)
Total	(106)	(341)
Non-U.S. government
Fair Value
12 Months or Greater	8,316	18,995
Less Than 12 Months	30,086	50,080
Total	38,402	69,075
Gross Unrealized Losses
12 Months or Greater	(1,794)	(2,633)
Less Than 12 Months	(983)	(1,256)
Total	(2,777)	(3,889)
Corporate
Fair Value
12 Months or Greater	8,003	54,295
Less Than 12 Months	42,304	81,047
Total	50,307	135,342
Gross Unrealized Losses
12 Months or Greater	(1,800)	(2,394)
Less Than 12 Months	(828)	(1,035)
Total	(2,628)	(3,429)
Municipal
Fair Value
12 Months or Greater	0	0
Less Than 12 Months	3,132	4,609
Total	3,132	4,609
Gross Unrealized Losses
12 Months or Greater	0	0
Less Than 12 Months	(21)	(36)
Total	$ (21)	(36)
Residential mortgage-backed
Fair Value
12 Months or Greater		71
Less Than 12 Months		0
Total		71
Gross Unrealized Losses
12 Months or Greater		(1)
Less Than 12 Months		0
Total		(1)
Asset-backed
Fair Value
12 Months or Greater		4,649
Less Than 12 Months		0
Total		4,649
Gross Unrealized Losses
12 Months or Greater		(10)
Less Than 12 Months		0
Total		$ (10)

Investments - Other Than Tempor

Investments - Other Than Temporary Impairment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
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	$ 0

Investments - Credit Ratings of

Investments - Credit Ratings of Fixed Maturity and Short-Term Investments, Trading (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 4,916,025
Fair Value	4,878,927
Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 222,557
Marketable Securities Member | Portfolio Concentration Risk Member | Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	100.00%
Trading and Available for Sale Securities | Credit Rating Concentration Risk | Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	4.60%
AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,801,146
AAA Rated | Trading and Available for Sale Securities | Credit Rating Concentration Risk | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	36.90%
AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 748,180
AA Rated | Trading and Available for Sale Securities | Credit Rating Concentration Risk | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	15.30%
A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,405,407
A Rated | Trading and Available for Sale Securities | Credit Rating Concentration Risk | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	28.80%
BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 673,544
BBB Rated | Trading and Available for Sale Securities | Credit Rating Concentration Risk | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	13.80%
Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 28,093
Not Rated | Trading and Available for Sale Securities | Credit Rating Concentration Risk
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	0.60%
U.S. government and agency
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 857,530
Fair Value	852,984
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 Member | Portfolio Concentration Risk Member | Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	17.50%
U.S. government and agency | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 846,698
U.S. government and agency | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	6,286
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
Non-U.S. government
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	362,797
Fair Value	352,786
Non-U.S. government | Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 0
Non-U.S. government | Marketable Securities Member | Portfolio Concentration Risk Member | Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	7.20%
Non-U.S. government | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 140,357
Non-U.S. government | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	150,569
Non-U.S. government | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	43,771
Non-U.S. government | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	18,089
Non-U.S. 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	2,561,305
Fair Value	2,545,977
Corporate | Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 149,898
Corporate | Marketable Securities Member | Portfolio Concentration Risk Member | Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	52.20%
Corporate | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 105,081
Corporate | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	465,224
Corporate | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	1,199,452
Corporate | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	615,538
Corporate | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	10,784
Municipal
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	54,200
Fair Value	53,757
Municipal | Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 0
Municipal | Marketable Securities Member | Portfolio Concentration Risk Member | Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	1.10%
Municipal | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 25,566
Municipal | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	25,834
Municipal | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	2,357
Municipal | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
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	379,004
Fair Value	374,055
Residential mortgage-backed | Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 97
Residential mortgage-backed | Marketable Securities Member | Portfolio Concentration Risk Member | Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	7.70%
Residential mortgage-backed | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 370,067
Residential mortgage-backed | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	403
Residential mortgage-backed | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	3,487
Residential mortgage-backed | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	0
Residential mortgage-backed | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	1
Commercial mortgage-backed
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	220,727
Fair Value	217,212
Commercial mortgage-backed | Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 77
Commercial mortgage-backed | Marketable Securities Member | Portfolio Concentration Risk Member | Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	4.40%
Commercial mortgage-backed | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 100,065
Commercial mortgage-backed | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	41,542
Commercial mortgage-backed | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	41,837
Commercial mortgage-backed | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	16,383
Commercial mortgage-backed | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	17,308
Asset-backed
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	480,462
Fair Value	482,156
Asset-backed | Non-Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 72,485
Asset-backed | Marketable Securities Member | Portfolio Concentration Risk Member | Trading Securities and Available for Sale Securities
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
% of Total Investments	9.90%
Asset-backed | AAA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 213,312
Asset-backed | AA Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	58,322
Asset-backed | A Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	114,503
Asset-backed | BBB Rated | Investment Grade
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	23,534
Asset-backed | Not Rated
Schedule of Trading Securities and Available-for-sale Securities [Line Items]
Amortized Cost	$ 0

Investments - Other Investments

Investments - Other Investments, at Fair Value (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)fund	Dec. 31, 2015USD ($)
Other Investments [Line Items]
Other investments, at fair value	$ 937,047	$ 980,289
Valuation lag period	3 months
Unfunded commitments	$ 144,000
Private equities and private equity funds
Other Investments [Line Items]
Other investments, at fair value	300,529	232,372
Unfunded commitments	144,000
Fixed income funds
Other Investments [Line Items]
Other investments, at fair value	249,023	280,749
Fixed income hedge funds
Other Investments [Line Items]
Other investments, at fair value	$ 85,976	89,154
Imposed lock-up period (up to) (years)	3 years
Number of days to give notice for quarterly hedge fund redemptions	90 days
Gates or side-pocket investments	$ 500
Equity funds
Other Investments [Line Items]
Other investments, at fair value	223,571	147,390
Multi-strategy hedge fund
Other Investments [Line Items]
Other investments, at fair value	0	99,020
Real estate debt fund
Other Investments [Line Items]
Other investments, at fair value	$ 0	54,829
Redemption request period (days)	10 days
CLO equities
Other Investments [Line Items]
Other investments, at fair value	$ 61,565	61,702
CLO equity funds
Other Investments [Line Items]
Other investments, at fair value	$ 15,440	13,928
Number of CLO equity funds | fund	2
Other
Other Investments [Line Items]
Other investments, at fair value	$ 943	$ 1,145
CLO Equity Fund One
Other Investments [Line Items]
Other investments, at fair value	$ 4,100
CLO Equity Fund One | Minimum
Other Investments [Line Items]
CLO equity fund pay out period (years)	1 year
CLO Equity Fund One | Maximum
Other Investments [Line Items]
CLO equity fund pay out period (years)	5 years
CLO Equity Fund Two
Other Investments [Line Items]
Other investments, at fair value	$ 11,300

Investments - Other Investmen78

Investments - Other Investments, at Cost (Details)	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)contract	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)contract	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)contract	Dec. 31, 2015USD ($)contract	Dec. 31, 2014USD ($)
Other Investments [Line Items]
Other investments, at cost	$ 131,651,000				$ 133,071,000				$ 131,651,000	$ 133,071,000
Amount of net investment income included in earnings attributable to investments in life settlements	$ 42,229,000	$ 48,022,000	$ 44,932,000	$ 50,280,000	$ 44,265,000	$ 31,640,000	$ 25,265,000	$ 21,394,000	$ 185,463,000	$ 122,564,000	$ 66,024,000
Number of Contracts
0 – 1 year | contract	2				2				2	2
1 – 2 years | contract	7				4				7	4
2 – 3 years | contract	11				19				11	19
3 – 4 years | contract	17				14				17	14
4 – 5 years | contract	16				16				16	16
Thereafter | contract	181				221				181	221
Total | contract	234				276				234	276
Carrying Value
0 – 1 year	$ 461,000				$ 417,000				$ 461,000	$ 417,000
1 – 2 years	11,396,000				3,032,000				11,396,000	3,032,000
2 – 3 years	15,338,000				24,072,000				15,338,000	24,072,000
3 – 4 years	17,013,000				9,695,000				17,013,000	9,695,000
4 – 5 years	10,377,000				9,025,000				10,377,000	9,025,000
Thereafter	77,066,000				86,830,000				77,066,000	86,830,000
Total	131,651,000				133,071,000				131,651,000	133,071,000
Face Value (Death Benefits)
0 – 1 year	700,000				700,000				700,000	700,000
1 – 2 years	18,337,000				5,000,000				18,337,000	5,000,000
2 – 3 years	29,715,000				39,123,000				29,715,000	39,123,000
3 – 4 years	32,189,000				20,932,000				32,189,000	20,932,000
4 – 5 years	23,302,000				22,457,000				23,302,000	22,457,000
Thereafter	431,034,000				491,499,000				431,034,000	491,499,000
Total	535,277,000				$ 579,711,000				535,277,000	579,711,000
Life Settlement Contracts, Investment Method, Premiums to be Paid, Fiscal Year Maturity [Abstract]
Life insurance premiums payable in 2017	17,800,000								17,800,000
Life insurance premiums payable in 2018	17,500,000								17,500,000
Life insurance premiums payable in 2019	17,700,000								17,700,000
Life insurance premiums payable in 2020	16,900,000								16,900,000
Life insurance premiums payable in 2021	$ 15,600,000								15,600,000
Life Settlements
Other Investments [Line Items]
Amount of net investment income included in earnings attributable to investments in life settlements									18,000,000	20,100,000
Impairment charges recognized in the period									$ 5,300,000	$ 0

Investments - Net Realized and

Investments - Net Realized and Unrealized Gains (Losses) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Gain (Loss) on Investments [Line Items]
Total net realized gains (losses) on sale									$ (7,036)	$ 15,859	$ 22,168
Change in fair value of embedded derivative									70,296	17,411	28,598
Total net unrealized gains (losses)									84,854	(57,382)	29,823
Net realized gains (losses) and change in fair value of embedded derivative	$ (61,570)	$ 66,608	$ 34,503	$ 38,277	$ (56,705)	$ (15,835)	$ (8,296)	$ 39,313	77,818	(41,523)	51,991
Proceeds from sales of available-for-sale securities									41,300	95,100	90,700
Fixed maturity investments
Gain (Loss) on Investments [Line Items]
Gross realized gains on fixed maturity securities, available-for-sale									405	396	196
Gross realized (losses) on fixed maturity securities, available-for-sale									(21)	(130)	(138)
Net realized gains (losses) on trading securities									1,848	(4,291)	3,372
Net unrealized gains (losses) on trading securities									36,314	(52,918)	9,890
Equity securities
Gain (Loss) on Investments [Line Items]
Net realized gains (losses) on trading securities									5,348	19,884	18,738
Net unrealized gains (losses) on trading securities									6,561	(21,875)	(8,665)
Funds held – directly managed
Gain (Loss) on Investments [Line Items]
Net realized gains (losses) on trading securities									(14,616)	0	0
Change in fair value of embedded derivative on funds held – directly managed									(28,317)	$ 0	$ 0
Net realized gains (losses) and change in fair value of embedded derivative									$ (42,933)

Investments - Net Investment In

Investments - Net Investment Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Investment Income [Line Items]
Gross investment income									$ 193,308	$ 131,902	$ 73,999
Investment expenses									(7,845)	(9,338)	(7,975)
Net investment income	$ 42,229	$ 48,022	$ 44,932	$ 50,280	$ 44,265	$ 31,640	$ 25,265	$ 21,394	185,463	122,564	66,024
Fixed maturities
Net Investment Income [Line Items]
Gross investment income									114,885	87,512	58,815
Net investment income									5,705
Short-term investments and cash and cash equivalents
Net Investment Income [Line Items]
Gross investment income									4,491	5,993	6,209
Net investment income									64
Equity securities
Net Investment Income [Line Items]
Gross investment income									4,874	5,580	5,671
Other investments
Net Investment Income [Line Items]
Gross investment income									22,515	11,712	1,335
Funds held
Net Investment Income [Line Items]
Gross investment income									22,583	234	1,376
Funds held – directly managed
Net Investment Income [Line Items]
Gross investment income									5,769	0	0
Net investment income									5,769
Life settlements and other
Net Investment Income [Line Items]
Gross investment income									$ 18,191	$ 20,871	$ 593

Investments - Restricted Assets

Investments - Restricted Assets (Detail)	Dec. 31, 2016USD ($)syndicate	Nov. 30, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Investments, Debt and Equity Securities [Abstract]
Restricted cash and cash equivalents	$ 363,774,000		$ 499,924,000	$ 531,948,000
Collateral in trust for third party agreements	1,975,022,000		1,993,065,000
Assets on deposit with regulatory authorities	882,400,000		906,973,000
Assets on deposit with regulatory authorities	177,263,000		212,544,000
Funds at Lloyd's	220,328,000		382,624,000
Restricted assets, total	$ 3,255,013,000		$ 3,495,206,000
Number of syndicates | syndicate	3
Cash and investments	$ 220,300,000
Collateral for line of credit facility	$ 122,000,000
FAL Facility | Loan facilities | Letters of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 140,000,000
Higher borrowing capacity option		$ 200,000,000

Funds Held - Directly Managed -

Funds Held - Directly Managed - Carrying Values of Assets and Liabilities Underlying Funds Held - Directly Managed (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	$ 4,611,160	$ 4,813,625
Funds held - directly managed	994,665	0
U.S. government and agency
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	840,274	742,918
Non-U.S. government
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	267,363	338,170
Corporate
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	2,387,322	2,564,618
Municipal
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	47,181	22,247
Commercial mortgage-backed
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	217,212	232,847
Asset-backed
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	478,280	$ 531,252
Funds held – directly managed
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	987,530
Funds held - directly managed, other assets	7,135
Funds held – directly managed | U.S. government and agency
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	47,885
Funds held – directly managed | Non-U.S. government
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	5,961
Funds held – directly managed | Corporate
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	663,556
Funds held – directly managed | Municipal
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	38,927
Funds held – directly managed | Commercial mortgage-backed
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	151,395
Funds held – directly managed | Asset-backed
Schedule of Funds Held, Directly Managed [Line Items]
Trading securities, debt	$ 79,806

Funds Held - Directly Managed83

Funds Held - Directly Managed - Contractual Maturities of Fixed Maturity Investments Underlying Funds Held - Directly Managed (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Amortized Cost
One year or less	$ 748,634
More than one year through two years	713,175
More than two years through five years	1,270,909
More than five years through ten years	651,539
More than ten years	186,066
Trading securities, amortized cost	4,646,161
Fair Value
One year or less	739,820
More than one year through two years	708,739
More than two years through five years	1,259,564
More than five years through ten years	648,156
More than ten years	185,861
Trading securities, debt	$ 4,611,160	$ 4,813,625
% of Total Fair Value
One year or less	16.00%
More than one year through two years	15.40%
More than two years through five years	27.30%
More than five years through ten years	14.10%
More than ten years	4.00%
Trading securities, percentage of fair value	100.00%
Commercial mortgage-backed
Amortized Cost
Securities without single maturity date	$ 220,727
Fair Value
Securities without single maturity date	217,212
Trading securities, debt	$ 217,212	232,847
% of Total Fair Value
Securities without single maturity date	4.70%
Asset-backed
Amortized Cost
Securities without single maturity date	$ 476,595
Fair Value
Securities without single maturity date	478,280
Trading securities, debt	$ 478,280	$ 531,252
% of Total Fair Value
Securities without single maturity date	10.40%
Funds held – directly managed
Amortized Cost
One year or less	$ 5,027
More than one year through two years	20,641
More than two years through five years	301,119
More than five years through ten years	253,811
More than ten years	197,236
Trading securities, amortized cost	1,015,848
Fair Value
One year or less	5,026
More than one year through two years	20,613
More than two years through five years	296,685
More than five years through ten years	244,967
More than ten years	189,038
Trading securities, debt	$ 987,530
% of Total Fair Value
One year or less	0.50%
More than one year through two years	2.10%
More than two years through five years	30.00%
More than five years through ten years	24.90%
More than ten years	19.10%
Trading securities, percentage of fair value	100.00%
Funds held – directly managed | Commercial mortgage-backed
Amortized Cost
Securities without single maturity date	$ 158,129
Trading securities, amortized cost	158,129
Fair Value
Securities without single maturity date	151,395
Trading securities, debt	$ 151,395
% of Total Fair Value
Securities without single maturity date	15.30%
Funds held – directly managed | Asset-backed
Amortized Cost
Securities without single maturity date	$ 79,885
Trading securities, amortized cost	79,885
Fair Value
Securities without single maturity date	79,806
Trading securities, debt	$ 79,806
% of Total Fair Value
Securities without single maturity date	8.10%

Funds Held - Directly Managed84

Funds Held - Directly Managed - Funds Held - Directly Managed, by Credit Rating (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 4,646,161
Fair Value	4,706,207	$ 4,925,120
Funds held – directly managed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	1,015,848
Fair Value	987,530
Funds held – directly managed | U.S. government and agency
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	50,257
Fair Value	47,885
Funds held – directly managed | Non-U.S. government
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	6,020
Fair Value	5,961
Funds held – directly managed | Corporate
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	681,484
Fair Value	663,556
Funds held – directly managed | Municipal
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	40,073
Fair Value	38,927
Funds held – directly managed | Commercial mortgage-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	158,129
Fair Value	151,395
Funds held – directly managed | Asset-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	79,885
Fair Value	$ 79,806
Funds held – directly managed | Trading securities | Portfolio Concentration Risk Member
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	100.00%
Funds held – directly managed | Trading securities | Portfolio Concentration Risk Member | U.S. government and agency
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	4.90%
Funds held – directly managed | Trading securities | Portfolio Concentration Risk Member | Non-U.S. government
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	0.60%
Funds held – directly managed | Trading securities | Portfolio Concentration Risk Member | Corporate
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	67.20%
Funds held – directly managed | Trading securities | Portfolio Concentration Risk Member | Municipal
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	3.90%
Funds held – directly managed | Trading securities | Portfolio Concentration Risk Member | Commercial mortgage-backed
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	15.30%
Funds held – directly managed | Trading securities | Portfolio Concentration Risk Member | Asset-backed
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	8.10%
Funds held – directly managed | AAA Rated | Investment Grade
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 275,993
Funds held – directly managed | AAA Rated | Investment Grade | U.S. government and agency
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	47,885
Funds held – directly managed | AAA Rated | Investment Grade | Non-U.S. government
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	0
Funds held – directly managed | AAA Rated | Investment Grade | Corporate
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	5,549
Funds held – directly managed | AAA Rated | Investment Grade | Municipal
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	0
Funds held – directly managed | AAA Rated | Investment Grade | Commercial mortgage-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	146,429
Funds held – directly managed | AAA Rated | Investment Grade | Asset-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 76,130
Funds held – directly managed | AAA Rated | Trading securities | Investment Grade | Credit Rating Concentration Risk
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	28.00%
Funds held – directly managed | AA Rated | Investment Grade
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 83,339
Funds held – directly managed | AA Rated | Investment Grade | U.S. government and agency
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	0
Funds held – directly managed | AA Rated | Investment Grade | Non-U.S. government
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	0
Funds held – directly managed | AA Rated | Investment Grade | Corporate
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	63,809
Funds held – directly managed | AA Rated | Investment Grade | Municipal
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	12,839
Funds held – directly managed | AA Rated | Investment Grade | Commercial mortgage-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	3,015
Funds held – directly managed | AA Rated | Investment Grade | Asset-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 3,676
Funds held – directly managed | AA Rated | Trading securities | Investment Grade | Credit Rating Concentration Risk
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	8.40%
Funds held – directly managed | A Rated | Investment Grade
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 265,927
Funds held – directly managed | A Rated | Investment Grade | U.S. government and agency
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	0
Funds held – directly managed | A Rated | Investment Grade | Non-U.S. government
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	2,913
Funds held – directly managed | A Rated | Investment Grade | Corporate
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	234,975
Funds held – directly managed | A Rated | Investment Grade | Municipal
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	26,088
Funds held – directly managed | A Rated | Investment Grade | Commercial mortgage-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	1,951
Funds held – directly managed | A Rated | Investment Grade | Asset-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 0
Funds held – directly managed | A Rated | Trading securities | Investment Grade | Credit Rating Concentration Risk
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	26.90%
Funds held – directly managed | BBB Rated | Investment Grade
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 362,271
Funds held – directly managed | BBB Rated | Investment Grade | U.S. government and agency
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	0
Funds held – directly managed | BBB Rated | Investment Grade | Non-U.S. government
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	3,048
Funds held – directly managed | BBB Rated | Investment Grade | Corporate
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	359,223
Funds held – directly managed | BBB Rated | Investment Grade | Municipal
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	0
Funds held – directly managed | BBB Rated | Investment Grade | Commercial mortgage-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	0
Funds held – directly managed | BBB Rated | Investment Grade | Asset-backed
Schedule of Funds Held, Directly Managed [Line Items]
Amortized Cost	$ 0
Funds held – directly managed | BBB Rated | Trading securities | Investment Grade | Credit Rating Concentration Risk
Schedule of Funds Held, Directly Managed [Line Items]
% of Total Investments	36.70%

Funds Held - Directly Managed85

Funds Held - Directly Managed - Net Realized and Unrealized Investment (Losses) Gains (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Gain (Loss) on Investments [Line Items]
Net realized gains (losses) and change in fair value of embedded derivative	$ (61,570)	$ 66,608	$ 34,503	$ 38,277	$ (56,705)	$ (15,835)	$ (8,296)	$ 39,313	$ 77,818	$ (41,523)	$ 51,991
Funds held – directly managed
Gain (Loss) on Investments [Line Items]
Net realized gains (losses) on fixed maturity securities									(14,616)	0	0
Change in fair value of embedded derivative									(28,317)	$ 0	$ 0
Net realized gains (losses) and change in fair value of embedded derivative									$ (42,933)

Funds Held - Directly Managed86

Funds Held - Directly Managed - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Investment Income [Line Items]
Investment income on funds held - directly managed	$ 42,229	$ 48,022	$ 44,932	$ 50,280	$ 44,265	$ 31,640	$ 25,265	$ 21,394	$ 185,463	$ 122,564	$ 66,024
Funds held – directly managed
Net Investment Income [Line Items]
Investment income on funds held - directly managed									5,769
Fixed maturities
Net Investment Income [Line Items]
Investment income on funds held - directly managed									5,705
Short-term investments and cash and cash equivalents
Net Investment Income [Line Items]
Investment income on funds held - directly managed									$ 64

Funds Held - Directly Managed87

Funds Held - Directly Managed - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Funds held - directly managed, carrying value	$ 1,023,000
Funds held - directly managed, embedded derivative, fair value	(28,300)
Funds held - directly managed	$ 994,665	$ 0

Fair Value Measurements - Categ

Fair Value Measurements - Categorized Investments and Assets Carried at Cost or Amortized Cost and Fair Value Among Levels (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	$ 4,611,160	$ 4,813,625
Funds held - directly managed	994,665	0
Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	987,530
Funds held - directly managed, other assets	7,135
U.S. government and agency
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	840,274	742,918
U.S. government and agency | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	47,885
Non-U.S. government
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	267,363	338,170
Non-U.S. government | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	5,961
Corporate
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	2,387,322	2,564,618
Corporate | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	663,556
Municipal
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	47,181	22,247
Municipal | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	38,927
Residential mortgage-backed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	373,528	381,573
Commercial mortgage-backed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	217,212	232,847
Commercial mortgage-backed | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	151,395
Asset-backed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	478,280	531,252
Asset-backed | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	79,806
Recurring
Assets, Fair Value Disclosure [Abstract]
Total investments	5,408,290	5,625,513
Funds held - directly managed, other assets	7,135
Funds held - directly managed	994,665
Derivative instruments	2,930
Liabilities, Fair Value Disclosure [Abstract]
Liabilities	74
Recurring | Equity securities | US
Assets, Fair Value Disclosure [Abstract]
Total investments	95,047	108,793
Recurring | Equity securities | International
Assets, Fair Value Disclosure [Abstract]
Total investments		2,702
Recurring | Other investments
Assets, Fair Value Disclosure [Abstract]
Total investments	937,047	980,289
Other investments	434,316	398,092
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total investments	91,287	102,169
Funds held - directly managed, other assets	0
Funds held - directly managed	0
Derivative instruments	0
Liabilities, Fair Value Disclosure [Abstract]
Liabilities	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity securities | US
Assets, Fair Value Disclosure [Abstract]
Total investments	91,287	99,467
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity securities | International
Assets, Fair Value Disclosure [Abstract]
Total investments		2,702
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other investments
Assets, Fair Value Disclosure [Abstract]
Other investments	0	0
Recurring | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total investments	5,138,686	5,299,184
Funds held - directly managed, other assets	7,135
Funds held - directly managed	994,665
Derivative instruments	2,930
Liabilities, Fair Value Disclosure [Abstract]
Liabilities	74
Recurring | Significant Other Observable Inputs (Level 2) | Equity securities | US
Assets, Fair Value Disclosure [Abstract]
Total investments	3,760	9,326
Recurring | Significant Other Observable Inputs (Level 2) | Equity securities | International
Assets, Fair Value Disclosure [Abstract]
Total investments		0
Recurring | Significant Other Observable Inputs (Level 2) | Other investments
Assets, Fair Value Disclosure [Abstract]
Other investments	357,438	321,076
Recurring | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total investments	178,317	224,160
Funds held - directly managed, other assets	0
Funds held - directly managed	0
Derivative instruments	0
Liabilities, Fair Value Disclosure [Abstract]
Liabilities	0
Recurring | Significant Unobservable Inputs (Level 3) | Equity securities | US
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Significant Unobservable Inputs (Level 3) | Equity securities | International
Assets, Fair Value Disclosure [Abstract]
Total investments		0
Recurring | Significant Unobservable Inputs (Level 3) | Other investments
Assets, Fair Value Disclosure [Abstract]
Other investments	76,878	77,016
Recurring | U.S. government and agency
Assets, Fair Value Disclosure [Abstract]
Total investments	852,984	767,759
Recurring | U.S. government and agency | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	47,885
Recurring | U.S. government and agency | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | U.S. government and agency | Quoted Prices in Active Markets for Identical Assets (Level 1) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | U.S. government and agency | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total investments	852,984	767,759
Recurring | U.S. government and agency | Significant Other Observable Inputs (Level 2) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	47,885
Recurring | U.S. government and agency | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | U.S. government and agency | Significant Unobservable Inputs (Level 3) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Non-U.S. government
Assets, Fair Value Disclosure [Abstract]
Total investments	352,786	423,954
Recurring | Non-U.S. government | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	5,961
Recurring | Non-U.S. government | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Non-U.S. government | Quoted Prices in Active Markets for Identical Assets (Level 1) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Non-U.S. government | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total investments	352,786	423,954
Recurring | Non-U.S. government | Significant Other Observable Inputs (Level 2) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	5,961
Recurring | Non-U.S. government | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Non-U.S. government | Significant Unobservable Inputs (Level 3) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Corporate
Assets, Fair Value Disclosure [Abstract]
Total investments	2,545,978	2,745,002
Recurring | Corporate | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	663,556
Recurring | Corporate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Corporate | Quoted Prices in Active Markets for Identical Assets (Level 1) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Corporate | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total investments	2,471,444	2,745,002
Recurring | Corporate | Significant Other Observable Inputs (Level 2) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	663,556
Recurring | Corporate | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total investments	74,534	0
Recurring | Corporate | Significant Unobservable Inputs (Level 3) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Municipal
Assets, Fair Value Disclosure [Abstract]
Total investments	53,757	28,174
Recurring | Municipal | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Municipal | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total investments	53,757	28,174
Recurring | Municipal | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Residential mortgage-backed
Assets, Fair Value Disclosure [Abstract]
Total investments	374,055	382,288
Recurring | Residential mortgage-backed | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	38,927
Recurring | Residential mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Residential mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Residential mortgage-backed | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total investments	374,055	382,288
Recurring | Residential mortgage-backed | Significant Other Observable Inputs (Level 2) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	38,927
Recurring | Residential mortgage-backed | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Residential mortgage-backed | Significant Unobservable Inputs (Level 3) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Commercial mortgage-backed
Assets, Fair Value Disclosure [Abstract]
Total investments	217,212	232,847
Recurring | Commercial mortgage-backed | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	151,395
Recurring | Commercial mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Commercial mortgage-backed | Quoted Prices in Active Markets for Identical Assets (Level 1) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Commercial mortgage-backed | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total investments	204,999	206,143
Recurring | Commercial mortgage-backed | Significant Other Observable Inputs (Level 2) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	151,395
Recurring | Commercial mortgage-backed | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total investments	12,213	26,704
Recurring | Commercial mortgage-backed | Significant Unobservable Inputs (Level 3) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Asset-backed
Assets, Fair Value Disclosure [Abstract]
Total investments	482,155	535,902
Recurring | Asset-backed | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	79,806
Recurring | Asset-backed | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total investments	0	0
Recurring | Asset-backed | Quoted Prices in Active Markets for Identical Assets (Level 1) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	0
Recurring | Asset-backed | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total investments	467,463	415,462
Recurring | Asset-backed | Significant Other Observable Inputs (Level 2) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	79,806
Recurring | Asset-backed | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total investments	14,692	$ 120,440
Recurring | Asset-backed | Significant Unobservable Inputs (Level 3) | Funds held – directly managed
Assets, Fair Value Disclosure [Abstract]
Trading securities, debt	$ 0

Fair Value Measurements - Other

Fair Value Measurements - Other Investments (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments shown on balance sheets	$ 5,408,290	$ 5,625,513
Other Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other investments measured at fair value	434,316	398,092
Other investments measured at NAV as practical expedient	502,731	582,197
Total other investments shown on balance sheets	$ 937,047	$ 980,289

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between Levels 2 and 3	$ 64.1
Transfers between Levels 3 and 2		$ 2.3
Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between Levels 2 and 3	2.8
Transfers between Levels 3 and 2		0.6
Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between Levels 2 and 3	23.6
Transfers between Levels 3 and 2		37.8
Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between Levels 2 and 3	$ 31.8
Transfers between Levels 3 and 2		$ 129.8

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation for Investments Measured At Fair Value on Recurring Basis Level 3 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning fair value	$ 224,160	$ 47,717
Purchases		106,433
Sales		(51,684)
Total realized and unrealized gains (losses)		(25,450)
Net transfers into (out of) Level 3		147,144
Ending fair value		224,160
Fair Value, Assets and Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning fair value	0
Purchases	0
Sales	0
Total realized and unrealized gains (losses)	0
Net transfers into (out of) Level 3	0
Ending fair value	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning fair value	224,160
Purchases	65,437
Sales	(65,774)
Total realized and unrealized gains (losses)	2,688
Net transfers into (out of) Level 3	(48,194)
Ending fair value	178,317	224,160
Fixed Maturity Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning fair value	147,144	600
Purchases	58,552	0
Sales	(52,841)	(600)
Total realized and unrealized gains (losses)	(3,222)	0
Net transfers into (out of) Level 3	(48,194)	147,144
Ending fair value	101,439	147,144
Other Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning fair value	77,016	42,267
Purchases	6,885	106,433
Sales	(12,933)	(46,084)
Total realized and unrealized gains (losses)	5,910	(25,600)
Net transfers into (out of) Level 3	0	0
Ending fair value	76,878	77,016
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning fair value	$ 0	4,850
Purchases		0
Sales		(5,000)
Total realized and unrealized gains (losses)		150
Net transfers into (out of) Level 3		0
Ending fair value		$ 0

Fair Value Measurements - Asset

Fair Value Measurements - Assets Carried at Cost or Amortized Cost (Details) - Life Settlement - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Life settlements	$ 129.5	$ 130.3
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Life settlements	$ 131.7	$ 133.1

Derivative Instruments (Details

Derivative Instruments (Details) € in Millions, CAD in Millions, AUD in Millions	12 Months Ended
	Dec. 31, 2016USD ($)derivative_instrument	Dec. 31, 2016EUR (€)	Dec. 31, 2016AUDderivative_instrument	Dec. 31, 2016CADderivative_instrument	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Derivative [Line Items]
Realized gain	$ 5,400,000
EGL Revolving Credit Facility | Loan facilities
Derivative [Line Items]
Proceeds from line of credit | €		€ 75
Designated as Hedging Instrument | Foreign Exchange Forward
Derivative [Line Items]
Number of derivative contracts | derivative_instrument	2		2	2
Gross Notional Amount	$ 82,642,000
Assets	2,930,000
Liabilities	74,000
Amount of Gains Deferred in AOCI (Effective Portion)	3,754,000
Designated as Hedging Instrument | Foreign Exchange Forward | Canada, Dollars
Derivative [Line Items]
Gross Notional Amount	37,175,000			CAD 50
Assets	177,000
Liabilities	0
Amount of Gains Deferred in AOCI (Effective Portion)	1,186,000
Designated as Hedging Instrument | Foreign Exchange Forward | Australia, Dollars
Derivative [Line Items]
Gross Notional Amount	45,500,000		AUD 63
Assets	2,753,000
Liabilities	74,000
Amount of Gains Deferred in AOCI (Effective Portion)	$ 2,568,000
Not Designated as Hedging Instrument | Equity Option
Derivative [Line Items]
Cost					$ 5,500,000	$ 0	$ 0

Reinsurance Balances Recovera94

Reinsurance Balances Recoverable - Summary of Reinsurance Reserves Recoverable (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effects of Reinsurance [Line Items]
Outstanding losses	$ 810,394	$ 777,556
IBNR	593,562	605,524
Fair value adjustments	(15,573)	(21,154)
Total reinsurance reserves recoverable	1,388,383	1,361,926
Paid losses recoverable	72,360	89,995
Net	1,460,743	1,451,921
Non-life Run-off
Effects of Reinsurance [Line Items]
Outstanding losses	621,288	587,164
IBNR	393,550	465,211
Fair value adjustments	(13,885)	(17,628)
Total reinsurance reserves recoverable	1,000,953	1,034,747	$ 800,709	$ 1,121,533
Paid losses recoverable	47,160	72,213
Net	1,048,113	1,106,960
Atrium
Effects of Reinsurance [Line Items]
Outstanding losses	6,438	6,772
IBNR	21,753	16,581
Fair value adjustments	1,818	2,499
Total reinsurance reserves recoverable	30,009	25,852	28,278	25,055
Paid losses recoverable	(1,081)	430
Net	28,928	26,282
StarStone
Effects of Reinsurance [Line Items]
Outstanding losses	182,478	182,076
IBNR	178,259	123,732
Fair value adjustments	(3,506)	(6,025)
Total reinsurance reserves recoverable	357,231	299,783	$ 325,209	$ 0
Paid losses recoverable	25,512	16,568
Net	382,743	316,351
Life and annuities
Effects of Reinsurance [Line Items]
Outstanding losses	190	1,544
IBNR	0	0
Fair value adjustments	0	0
Total reinsurance reserves recoverable	190	1,544
Paid losses recoverable	769	784
Net	$ 959	$ 2,328

Reinsurance Balances Recovera95

Reinsurance Balances Recoverable - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 1,460,743	$ 1,451,921
Increase (decrease) in reinsurance recoverable	21,866	(391,182)	$ (428,718)
Reinsurer concentration risk | Three non-rated reinsurers
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	512,200	337,600
Reinsurer concentration risk | Top Ten Reinsurers, Kayla Re
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	241,700
Reinsurer concentration risk | Top Ten Reinsurers, Lloyd's Syndicates
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	154,700	165,600
Reinsurer concentration risk | Reinsurance balances recoverable
Effects of Reinsurance [Line Items]
Reinsurance balances recoverable	$ 1,460,743	$ 1,451,921
Gross premiums written (percent)	100.00%	100.00%
Reinsurer concentration risk | Reinsurance balances recoverable | Two Reinsurers Accounting for More than 10% of Total Reinsurance Balances Receivable
Effects of Reinsurance [Line Items]
Gross premiums written (percent)	10.00%
Reinsurer concentration risk | Reinsurance balances recoverable | One Reinsurer Accounting for More than 10% of Total Reinsurance Balances Receivable
Effects of Reinsurance [Line Items]
Gross premiums written (percent)		10.00%
Non-Life Run-Off
Effects of Reinsurance [Line Items]
Increase (decrease) in reinsurance recoverable	$ 8,800

Reinsurance Balances Recovera96

Reinsurance Balances Recoverable - Reinsurance Balances Recoverable by Reinsurer (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	$ 1,460,743	$ 1,451,921
Reinsurance balances recoverable | Reinsurer concentration risk
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	$ 1,460,743	$ 1,451,921
% of Total	100.00%	100.00%
Reinsurance balances recoverable | Reinsurer concentration risk | Top Ten Reinsurers
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	$ 986,602	$ 890,308
% of Total	67.60%	61.40%
Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Greater Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	$ 459,024	$ 546,568
% of Total	31.40%	37.60%
Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Less Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	$ 15,117	$ 15,045
% of Total	1.00%	1.00%
Non-life Run-off
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	$ 1,048,113	$ 1,106,960
Non-life Run-off | Reinsurance balances recoverable | Reinsurer concentration risk
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	1,048,113	1,106,960
Non-life Run-off | Reinsurance balances recoverable | Reinsurer concentration risk | Top Ten Reinsurers
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	737,074	713,743
Non-life Run-off | Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Greater Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	301,856	383,898
Non-life Run-off | Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Less Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	9,183	9,319
Atrium
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	28,928	26,282
Atrium | Reinsurance balances recoverable | Reinsurer concentration risk
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	28,928	26,282
Atrium | Reinsurance balances recoverable | Reinsurer concentration risk | Top Ten Reinsurers
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	23,245	21,394
Atrium | Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Greater Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	4,827	4,253
Atrium | Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Less Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	856	635
StarStone
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	382,743	316,351
StarStone | Reinsurance balances recoverable | Reinsurer concentration risk
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	382,743	316,351
StarStone | Reinsurance balances recoverable | Reinsurer concentration risk | Top Ten Reinsurers
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	226,283	155,171
StarStone | Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Greater Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	152,341	158,417
StarStone | Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Less Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	4,119	2,763
Life and annuities
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	959	2,328
Life and annuities | Reinsurance balances recoverable | Reinsurer concentration risk
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	959	2,328
Life and annuities | Reinsurance balances recoverable | Reinsurer concentration risk | Top Ten Reinsurers
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	0	0
Life and annuities | Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Greater Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	0	0
Life and annuities | Reinsurance balances recoverable | Reinsurer concentration risk | Other Reinsurers' Balances Less Than $1 Million
Ceded Credit Risk [Line Items]
Reinsurance balances recoverable	$ 959	$ 2,328

Reinsurance Balances Recovera97

Reinsurance Balances Recoverable - Summary of Provisions for Uncollectible Reinsurance Balances Recoverable by Rating of Reinsurer (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Effects of Reinsurance [Line Items]
Gross	$ 1,635,259	$ 1,662,248
Provisions for Bad Debt	174,516	210,327
Net	$ 1,460,743	$ 1,451,921
Provisions as a % of Gross	10.70%	12.70%
Reinsurers rated A- or above
Effects of Reinsurance [Line Items]
Gross	$ 892,776	$ 1,029,844
Provisions for Bad Debt	35,184	46,969
Net	$ 857,592	$ 982,875
Provisions as a % of Gross	3.90%	4.60%
Secured | Reinsurers Rated Below A-
Effects of Reinsurance [Line Items]
Gross	$ 544,894	$ 388,399
Provisions for Bad Debt	0	0
Net	$ 544,894	$ 388,399
Provisions as a % of Gross	0.00%	0.00%
Unsecured | Reinsurers Rated Below A-
Effects of Reinsurance [Line Items]
Gross	$ 197,589	$ 244,005
Provisions for Bad Debt	139,332	163,358
Net	$ 58,257	$ 80,647
Provisions as a % of Gross	70.50%	66.90%

Losses and Loss Adjustment Ex98

Losses and Loss Adjustment Expenses - Total Losses and Loss Adjustment Expense Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	$ 3,267,231	$ 3,283,862
IBNR	2,844,364	2,584,612
Fair value adjustments	(123,728)	(148,325)
Total gross liability for unpaid losses and LAE	5,987,867	5,720,149	$ 4,509,421	$ 4,219,905
Non-life Run-off
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	2,697,737	2,757,774
IBNR	2,153,994	1,991,009
Fair value adjustments	(135,368)	(163,329)
Total gross liability for unpaid losses and LAE	4,716,363	4,585,454	3,435,010	4,004,513
Atrium
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	67,379	68,913
IBNR	132,240	115,613
Fair value adjustments	12,503	16,491
Total gross liability for unpaid losses and LAE	212,122	201,017	212,611	215,392
StarStone
Liability for Claims and Claims Adjustment Expense [Line Items]
Outstanding losses	502,115	457,175
IBNR	558,130	477,990
Fair value adjustments	(863)	(1,487)
Total gross liability for unpaid losses and LAE	$ 1,059,382	$ 933,678	$ 861,800	$ 0

Losses and Loss Adjustment Ex99

Losses and Loss Adjustment Expenses - Reconciliation of Beginning and Ending Reserves for Losses and Loss Adjustment Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as at January 1				$ 5,720,149				$ 4,509,421	$ 5,720,149	$ 4,509,421	$ 4,219,905
Less: reinsurance reserves recoverable				1,361,926					1,361,926
Less: deferred charge on retroactive reinsurance				255,911				0	255,911	0	0
Net balance as at January 1				4,103,856				3,355,225	4,103,856	3,355,225	3,073,317
Net incurred losses and LAE:
Current period									493,016	476,364	327,817
Prior periods									(318,917)	(372,031)	(318,671)
Total net incurred losses and LAE	$ 1,321	$ (6,902)	$ 96,462	83,218	$ (64,062)	$ 32,359	$ 65,900	70,136	174,099	104,333	9,146
Net paid losses:
Current period									(79,579)	(99,933)	(166,796)
Prior periods									(753,478)	(681,956)	(420,715)
Total net paid losses									(833,057)	(781,889)	(587,511)
Effect of exchange rate movement									(46,903)	(65,069)	(69,804)
Acquired on purchase of subsidiaries									10,019	878,815	901,447
Assumed business									1,340,444	612,441	28,630
Ceded business									(243,335)	0	0
Net balance as at December 31	4,505,123				4,103,856				4,505,123	4,103,856	3,355,225
Plus: reinsurance reserves recoverable	1,388,383				1,361,926				1,388,383	1,361,926
Plus: deferred charge on retroactive reinsurance	94,551				255,911				94,551	255,911	0
Balance as at December 31	5,987,867				5,720,149				5,987,867	5,720,149	4,509,421
Non-Life Run-off Segment, Atrium Segment, and Starstone Segment
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Less: reinsurance reserves recoverable				1,360,382				1,154,196	1,360,382	1,154,196	1,146,588
Net paid losses:
Plus: reinsurance reserves recoverable	1,388,193				1,360,382				1,388,193	1,360,382	1,154,196
Non-life Run-off
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as at January 1				4,585,454				3,435,010	4,585,454	3,435,010	4,004,513
Less: reinsurance reserves recoverable				1,034,747				800,709	1,034,747	800,709	1,121,533
Less: deferred charge on retroactive reinsurance				255,911				0	255,911	0	0
Net balance as at January 1				3,294,796				2,634,301	3,294,796	2,634,301	2,882,980
Net incurred losses and LAE:
Current period									5,829	39,924	24,235
Prior periods									(291,710)	(310,754)	(288,946)
Total net incurred losses and LAE									(285,881)	(270,830)	(264,711)
Net paid losses:
Current period									(3,869)	(16,049)	(87,681)
Prior periods									(529,937)	(501,246)	(312,415)
Total net paid losses									(533,806)	(517,295)	(400,096)
Effect of exchange rate movement									(27,478)	(42,636)	(49,267)
Acquired on purchase of subsidiaries									10,019	878,815	436,765
Assumed business									1,340,444	612,441	28,630
Ceded business									(177,235)	0	0
Net balance as at December 31	3,620,859				3,294,796				3,620,859	3,294,796	2,634,301
Plus: reinsurance reserves recoverable	1,000,953				1,034,747				1,000,953	1,034,747	800,709
Plus: deferred charge on retroactive reinsurance	94,551				255,911				94,551	255,911	0
Balance as at December 31	4,716,363				4,585,454				4,716,363	4,585,454	3,435,010
Atrium
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as at January 1				201,017				212,611	201,017	212,611	215,392
Less: reinsurance reserves recoverable				25,852				28,278	25,852	28,278	25,055
Net balance as at January 1				175,165				184,333	175,165	184,333	190,337
Net incurred losses and LAE:
Current period									71,358	69,400	74,094
Prior periods									(12,971)	(21,921)	(18,666)
Total net incurred losses and LAE									58,387	47,479	55,428
Net paid losses:
Current period									(23,582)	(21,145)	(29,626)
Prior periods									(24,416)	(30,890)	(27,985)
Total net paid losses									(47,998)	(52,035)	(57,611)
Effect of exchange rate movement									(3,441)	(4,612)	(3,821)
Acquired on purchase of subsidiaries									0	0	0
Net balance as at December 31	182,113				175,165				182,113	175,165	184,333
Plus: reinsurance reserves recoverable	30,009				25,852				30,009	25,852	28,278
Balance as at December 31	212,122				201,017				212,122	201,017	212,611
StarStone
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance as at January 1				933,678				861,800	933,678	861,800	0
Less: reinsurance reserves recoverable				299,783				325,209	299,783	325,209	0
Net balance as at January 1				$ 633,895				$ 536,591	633,895	536,591	0
Net incurred losses and LAE:
Current period									415,829	367,040	229,488
Prior periods									(14,236)	(39,356)	(11,059)
Total net incurred losses and LAE									401,593	327,684	218,429
Net paid losses:
Current period									(52,128)	(62,739)	(49,489)
Prior periods									(199,125)	(149,820)	(80,315)
Total net paid losses									(251,253)	(212,559)	(129,804)
Effect of exchange rate movement									(15,984)	(17,821)	(16,716)
Acquired on purchase of subsidiaries									0	0	464,682
Assumed business									0	0	0
Ceded business									(66,100)	0	0
Net balance as at December 31	702,151				633,895				702,151	633,895	536,591
Plus: reinsurance reserves recoverable	357,231				299,783				357,231	299,783	325,209
Balance as at December 31	$ 1,059,382				$ 933,678				$ 1,059,382	$ 933,678	$ 861,800

Losses and Loss Adjustment E100

Losses and Loss Adjustment Expenses - Net (Reduction) Increase in Ultimate Losses and Loss Adjustment Expense Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Prior Period
Net losses paid, prior period									$ 753,478	$ 681,956	$ 420,715
Prior periods									(318,917)	(372,031)	(318,671)
Current Period
Net losses paid, current period									79,579	99,933	166,796
Net incurred losses and LAE, current period									493,016	476,364	327,817
Total
Net losses paid									833,057	781,889	587,511
Net change in case and LAE reserves									(535,884)	(278,825)	(275,494)
Net change in IBNR reserves									(258,041)	(324,026)	(231,357)
Amortization of deferred charges									168,827	15,265	0
Increase (reduction) in estimates of net ultimate losses									207,959	194,303	80,660
Increase (reduction) in provisions for bad debt									(13,822)	(25,271)	(7,700)
Increase (reduction) in provisions for unallocated LAE									(40,267)	(59,199)	(53,970)
Amortization of fair value adjustments									20,229	(5,500)	(9,844)
Total net incurred losses and LAE	$ 1,321	$ (6,902)	$ 96,462	$ 83,218	$ (64,062)	$ 32,359	$ 65,900	$ 70,136	174,099	104,333	9,146
Non-life Run-off
Prior Period
Net losses paid, prior period									529,937	501,246	312,415
Net change in case and LAE reserves, prior period									(608,168)	(366,262)	(285,814)
Net change in IBNR reserves, prior period									(349,726)	(377,722)	(262,384)	$ 265,200
Amortization of deferred charges, prior period									168,827	15,265	0
Increase (reduction) in estimates of net ultimate losses, prior period									(259,130)	(227,473)	(235,783)
Increase (reduction) in provisions for bad debt, prior period									(13,822)	(25,271)	(7,700)
Increase (reduction) in provisions for unallocated LAE, prior period									(44,190)	(62,653)	(49,445)
Amortization of fair value adjustments, prior period									25,432	4,643	3,982
Prior periods									(291,710)	(310,754)	(288,946)
Current Period
Net losses paid, current period									3,869	16,049	87,681
Net change in case and LAE reserves, current period									(617)	10,927	(24,600)
Net change in IBNR reserves, current period									2,342	12,948	(39,400)
Amortization of deferred charges, current period									0	0	0
Increase (reduction) in estimates of net ultimate losses, current period									5,594	39,924	23,681
Increase (reduction) in provisions for bad debt, current period									0	0	0
Increase (reduction) in provisions for unallocated LAE, current period									235	0	554
Amortization of fair value adjustments, current period									0	0	0
Net incurred losses and LAE, current period									5,829	39,924	24,235
Total
Net losses paid									533,806	517,295	400,096
Net change in case and LAE reserves									(608,785)	(355,335)	(310,414)
Net change in IBNR reserves									(347,384)	(364,774)	(301,784)
Amortization of deferred charges									168,827	15,265	0
Increase (reduction) in estimates of net ultimate losses									(253,536)	(187,549)	(212,102)
Increase (reduction) in provisions for bad debt									(13,822)	(25,271)	(7,700)
Increase (reduction) in provisions for unallocated LAE									(43,955)	(62,653)	(48,891)
Amortization of fair value adjustments									25,432	4,643	3,982
Total net incurred losses and LAE									(285,881)	(270,830)	(264,711)
Atrium
Prior Period
Net losses paid, prior period									24,416	30,890	27,985
Net change in case and LAE reserves, prior period									(13,115)	(18,213)	(16,986)
Net change in IBNR reserves, prior period									(20,543)	(27,382)	(18,114)
Increase (reduction) in estimates of net ultimate losses, prior period									(9,242)	(14,705)	(7,115)
Increase (reduction) in provisions for unallocated LAE, prior period									(421)	(608)	(486)
Amortization of fair value adjustments, prior period									(3,308)	(6,608)	(11,065)
Prior periods									(12,971)	(21,921)	(18,666)
Current Period
Net losses paid, current period									23,582	21,145	29,626
Net change in case and LAE reserves, current period									12,967	17,504	14,302
Net change in IBNR reserves, current period									34,243	30,226	29,671
Increase (reduction) in estimates of net ultimate losses, current period									70,792	68,875	73,599
Increase (reduction) in provisions for unallocated LAE, current period									566	525	495
Amortization of fair value adjustments, current period									0	0	0
Net incurred losses and LAE, current period									71,358	69,400	74,094
Total
Net losses paid									47,998	52,035	57,611
Net change in case and LAE reserves									(148)	(709)	(2,684)
Net change in IBNR reserves									13,700	2,844	11,557
Amortization of deferred charges									0	0	0
Increase (reduction) in estimates of net ultimate losses									61,550	54,170	66,484
Increase (reduction) in provisions for bad debt									0	0	0
Increase (reduction) in provisions for unallocated LAE									145	(83)	9
Amortization of fair value adjustments									(3,308)	(6,608)	(11,065)
Total net incurred losses and LAE									58,387	47,479	55,428
StarStone
Prior Period
Net losses paid, prior period									199,125	149,820	80,315
Net change in case and LAE reserves, prior period									(51,309)	15,772
Net change in IBNR reserves, prior period									(156,546)	(200,730)
Increase (reduction) in estimates of net ultimate losses, prior period									(8,730)	(35,138)
Increase (reduction) in provisions for unallocated LAE, prior period									(3,611)	(683)
Amortization of fair value adjustments, prior period									(1,895)	(3,535)
Prior periods									(14,236)	(39,356)	(11,059)
Current Period
Net losses paid, current period									52,128	62,739	49,489
Net change in case and LAE reserves, current period									124,358	61,447
Net change in IBNR reserves, current period									232,189	238,634
Increase (reduction) in estimates of net ultimate losses, current period									408,675	362,820
Increase (reduction) in provisions for unallocated LAE, current period									7,154	4,220
Amortization of fair value adjustments, current period									0	0
Net incurred losses and LAE, current period									415,829	367,040	229,488
Total
Net losses paid									251,253	212,559	129,804
Net change in case and LAE reserves									73,049	77,219	37,604
Net change in IBNR reserves									75,643	37,904	58,870
Amortization of deferred charges									0	0	0
Increase (reduction) in estimates of net ultimate losses									399,945	327,682	226,278
Increase (reduction) in provisions for bad debt									0	0	0
Increase (reduction) in provisions for unallocated LAE									3,543	3,537	(5,088)
Amortization of fair value adjustments									(1,895)	(3,535)	(2,761)
Total net incurred losses and LAE									$ 401,593	$ 327,684	$ 218,429

Losses and Loss Adjustment E101

Losses and Loss Adjustment Expenses - Breakdown of Gross and Net Losses and LAE Reserves by Type of Exposure (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Liability for Claims and Claims Adjustment Expense [Line Items]
Total gross liability for unpaid losses and LAE	$ 5,987,867	$ 5,720,149	$ 4,509,421	$ 4,219,905
Total, Net	4,505,123	4,103,856	3,355,225	3,073,317
Non-life Run-off
Liability for Claims and Claims Adjustment Expense [Line Items]
OLR, Gross	2,616,123
IBNR, Gross	1,881,904
Total, Gross	4,498,027
OLR, Net	1,937,747
IBNR, Net	1,464,776
Total, Net	3,402,523
Unallocated loss adjustment expenses	218,336
Total gross liability for unpaid losses and LAE	4,716,363	4,585,454	3,435,010	4,004,513
Total, Net	3,620,859	$ 3,294,796	$ 2,634,301	$ 2,882,980
Non-life Run-off | Asbestos
Liability for Claims and Claims Adjustment Expense [Line Items]
OLR, Gross	240,863
IBNR, Gross	548,180
Total, Gross	789,043
OLR, Net	230,983
IBNR, Net	533,361
Total, Net	764,344
Non-life Run-off | Environmental
Liability for Claims and Claims Adjustment Expense [Line Items]
OLR, Gross	94,432
IBNR, Gross	67,646
Total, Gross	162,078
OLR, Net	91,362
IBNR, Net	65,507
Total, Net	156,869
Non-life Run-off | General casualty
Liability for Claims and Claims Adjustment Expense [Line Items]
OLR, Gross	427,733
IBNR, Gross	316,227
Total, Gross	743,960
OLR, Net	301,699
IBNR, Net	190,053
Total, Net	491,752
Unallocated loss adjustment expenses	36,112
Total gross liability for unpaid losses and LAE	780,072
Non-life Run-off | Workers' compensation/personal accident
Liability for Claims and Claims Adjustment Expense [Line Items]
OLR, Gross	1,360,743
IBNR, Gross	693,585
Total, Gross	2,054,328
OLR, Net	915,704
IBNR, Net	457,119
Total, Net	1,372,823
Unallocated loss adjustment expenses	99,718
Total gross liability for unpaid losses and LAE	2,154,046
Non-life Run-off | Marine, aviation and transit
Liability for Claims and Claims Adjustment Expense [Line Items]
OLR, Gross	45,240
IBNR, Gross	34,873
Total, Gross	80,113
OLR, Net	39,816
IBNR, Net	34,678
Total, Net	74,494
Non-life Run-off | Construction defect
Liability for Claims and Claims Adjustment Expense [Line Items]
OLR, Gross	39,622
IBNR, Gross	120,459
Total, Gross	160,081
OLR, Net	32,449
IBNR, Net	88,647
Total, Net	121,096
Non-life Run-off | Other
Liability for Claims and Claims Adjustment Expense [Line Items]
OLR, Gross	407,490
IBNR, Gross	100,934
Total, Gross	508,424
OLR, Net	325,734
IBNR, Net	95,411
Total, Net	$ 421,145

Losses and Loss Adjustment E102

Losses and Loss Adjustment Expenses - Incurred and Paid Loss Development Information, and IBNR Liabilities and Cumulative Loss Frequency (Details) $ in Thousands	Dec. 31, 2016USD ($)claim	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)	Dec. 31, 2011USD ($)	Dec. 31, 2010USD ($)	Dec. 31, 2009USD ($)	Dec. 31, 2008USD ($)	Dec. 31, 2007USD ($)
Non-life Run-off | General casualty
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 131,732
IBNR losses and loss expenses, net of reinsurance	107,668
IBNR losses and loss expenses, net of reinsurance - assumed business	36,501	$ 3,685	$ 5,263	$ 0	$ 25,703	$ 0	$ 3,633	$ 0	$ 10,740	$ 0
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	1,343,720
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	1,104,318
All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance	266,163
Total outstanding liabilities for unpaid losses and LAE, net of reinsurance	505,565
Non-life Run-off | General casualty | Accident Year - 2007
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	2,679	1,929	6,302	7,411	8,757	15,084	10,053	13,847	26,555	22,745
IBNR losses and loss expenses, net of reinsurance	1,579	1,049	3,356	3,996	2,986	7,485	6,339	6,108	8,409	8,983
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	88,081	86,364	87,929	89,022	86,583	92,460	81,587	77,504	69,095	50,012
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 83,823	83,386	78,271	77,614	74,840	69,892	65,195	57,548	34,131	18,284
Cumulative number of reported claims | claim	15,904
Non-life Run-off | General casualty | Accident Year - 2008
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 7,890	9,138	11,239	16,296	21,275	29,183	36,785	55,854	43,164
IBNR losses and loss expenses, net of reinsurance	4,682	8,450	6,491	7,528	5,605	12,253	15,134	4,956	16,731
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	155,909	158,178	155,177	152,589	147,317	145,526	137,678	114,684	78,187
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 143,337	140,589	137,448	128,766	120,437	104,090	85,759	53,874	18,292
Cumulative number of reported claims | claim	10,363
Non-life Run-off | General casualty | Accident Year - 2009
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 11,333	14,562	15,044	22,834	34,708	45,685	37,028	19,205
IBNR losses and loss expenses, net of reinsurance	5,247	5,363	9,170	12,272	8,240	15,393	16,784	14,131
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	173,855	173,304	168,363	164,233	146,500	128,373	95,064	47,683
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 157,275	153,379	144,148	129,127	103,552	67,294	41,253	14,347
Cumulative number of reported claims | claim	10,378
Non-life Run-off | General casualty | Accident Year - 2010
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 23,460	35,806	42,088	59,566	81,789	92,211	41,785
IBNR losses and loss expenses, net of reinsurance	18,026	13,513	19,770	28,064	16,032	25,904	22,364
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	270,864	260,599	235,009	229,345	200,723	169,525	82,340
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 229,377	211,280	173,150	141,715	102,903	51,410	18,191
Cumulative number of reported claims | claim	12,439
Non-life Run-off | General casualty | Accident Year - 2011
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 19,945	25,227	32,499	33,465	48,609	19,805
IBNR losses and loss expenses, net of reinsurance	20,683	18,042	25,659	34,767	23,948	33,180
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	191,245	186,384	177,382	166,450	134,667	73,694
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 150,616	143,116	119,224	98,218	62,110	20,709
Cumulative number of reported claims | claim	10,247
Non-life Run-off | General casualty | Accident Year - 2012
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 34,804	37,651	53,386	56,594	44,029
IBNR losses and loss expenses, net of reinsurance	21,224	19,383	45,872	64,756	61,807
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	280,266	255,667	257,655	225,566	147,850
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 224,238	198,634	158,397	104,216	42,014
Cumulative number of reported claims | claim	22,667
Non-life Run-off | General casualty | Accident Year - 2013
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 16,995	22,681	23,432	20,677
IBNR losses and loss expenses, net of reinsurance	16,534	17,200	58,446	70,755
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	122,148	113,574	135,171	117,545
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 88,618	73,693	53,293	26,112
Cumulative number of reported claims | claim	15,136
Non-life Run-off | General casualty | Accident Year - 2014
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 10,022	12,537	10,489
IBNR losses and loss expenses, net of reinsurance	9,894	12,839	32,309
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	42,370	39,072	48,808
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 22,454	13,696	6,010
Cumulative number of reported claims | claim	3,421
Non-life Run-off | General casualty | Accident Year - 2015
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 4,356	3,294
IBNR losses and loss expenses, net of reinsurance	7,573	7,697
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	16,292	12,949
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 4,364	1,958
Cumulative number of reported claims | claim	871
Non-life Run-off | General casualty | Accident Year - 2016
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 248
IBNR losses and loss expenses, net of reinsurance	2,226
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	2,690
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 216
Cumulative number of reported claims | claim	111
Non-life Run-off | Workers' compensation
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 239,872
IBNR losses and loss expenses, net of reinsurance	219,651
IBNR losses and loss expenses, net of reinsurance - assumed business	100,000	0	0	0		0	5,954	5,323	0	0
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	2,047,993
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	1,588,469
All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance	1,042,179
Total outstanding liabilities for unpaid losses and LAE, net of reinsurance	1,501,703
Non-life Run-off | Workers' compensation | Accident Year - 2007
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	22,457	31,975	57,819	51,970	47,688	59,768	68,929	72,373	85,044	106,913
IBNR losses and loss expenses, net of reinsurance	8,488	4,180	7,450	8,794	7,006	8,498	9,993	23,382	38,830	87,248
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	336,989	335,568	358,015	345,358	326,776	323,278	308,723	293,677	275,598	267,160
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 306,044	299,413	292,746	284,594	272,082	255,011	229,800	197,923	151,725	72,998
Cumulative number of reported claims | claim	44,305
Non-life Run-off | Workers' compensation | Accident Year - 2008
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 22,378	28,878	36,483	42,524	48,864	68,516	86,070	93,156	103,568
IBNR losses and loss expenses, net of reinsurance	11,586	6,449	10,624	12,420	11,065	15,087	18,966	43,067	78,862
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	361,402	357,863	361,369	354,645	342,397	341,690	325,463	300,657	265,651
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 327,438	322,537	314,261	299,701	282,468	258,086	220,427	164,433	83,221
Cumulative number of reported claims | claim	40,849
Non-life Run-off | Workers' compensation | Accident Year - 2009
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 26,589	34,730	34,033	39,846	49,318	75,756	96,353	83,064
IBNR losses and loss expenses, net of reinsurance	16,294	11,165	9,391	11,426	16,686	19,247	35,477	77,265
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	335,481	329,178	320,485	310,848	303,106	294,062	278,324	236,306
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 292,598	283,283	277,061	259,577	237,103	199,059	146,494	75,977
Cumulative number of reported claims | claim	41,127
Non-life Run-off | Workers' compensation | Accident Year - 2010
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 34,640	42,383	44,754	56,334	75,569	111,772	104,493
IBNR losses and loss expenses, net of reinsurance	24,435	26,945	28,348	17,772	14,819	16,597	67,115
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	347,575	344,185	337,002	326,412	308,810	291,192	256,618
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 288,499	274,857	263,900	252,306	218,422	162,822	85,009
Cumulative number of reported claims | claim	48,360
Non-life Run-off | Workers' compensation | Accident Year - 2011
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 31,324	48,552	63,975	55,414	80,618	84,408
IBNR losses and loss expenses, net of reinsurance	34,572	46,320	54,890	15,610	24,162	69,544
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	249,040	254,815	251,058	222,037	212,973	197,858
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 183,144	159,942	132,194	151,012	108,193	43,906
Cumulative number of reported claims | claim	46,975
Non-life Run-off | Workers' compensation | Accident Year - 2012
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 40,728	62,339	79,952	65,078	66,109
IBNR losses and loss expenses, net of reinsurance	48,173	71,755	95,026	45,307	86,194
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	221,803	225,014	230,513	198,054	189,571
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 132,902	90,921	55,534	87,669	37,267
Cumulative number of reported claims | claim	42,712
Non-life Run-off | Workers' compensation | Accident Year - 2013
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 37,299	56,882	63,372	35,976
IBNR losses and loss expenses, net of reinsurance	48,022	75,839	110,706	43,419
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	104,521	113,792	131,198	97,190
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 19,200	(18,929)	(42,879)	17,795
Cumulative number of reported claims | claim	22,189
Non-life Run-off | Workers' compensation | Accident Year - 2014
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 20,144	25,152	14,179
IBNR losses and loss expenses, net of reinsurance	24,705	45,657	51,216
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	77,180	82,487	73,154
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 32,332	11,678	7,760
Cumulative number of reported claims | claim	10,857
Non-life Run-off | Workers' compensation | Accident Year - 2015
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 4,104	6,017
IBNR losses and loss expenses, net of reinsurance	2,846	9,596
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	13,129	19,151
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 6,178	3,538
Cumulative number of reported claims | claim	2,869
Non-life Run-off | Workers' compensation | Accident Year - 2016
Claims Development [Line Items]
Unpaid reported losses and allocated loss adjustment expenses, net of reinsurance	$ 209
IBNR losses and loss expenses, net of reinsurance	530
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	873
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 134
Cumulative number of reported claims | claim	33
Atrium
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	$ 587,844
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	428,981
All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance	10,443
Total outstanding liabilities for unpaid losses and LAE, net of reinsurance	169,306
Atrium | Accident Year - 2007
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	1,610
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	60,302	60,162	61,660	60,418	61,858	68,842	68,567	62,305	68,768	39,003
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 56,806	55,857	54,611	54,298	50,028	48,544	46,467	41,837	35,836	$ 13,878
Cumulative number of reported claims | claim	282
Atrium | Accident Year - 2008
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 2,403
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	61,473	62,969	62,217	62,490	69,378	71,965	75,261	74,652	58,537
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 57,891	58,320	57,760	56,563	54,750	51,838	47,151	36,785	$ 15,060
Cumulative number of reported claims | claim	345
Atrium | Accident Year - 2009
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 1,822
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	45,060	45,693	46,927	50,169	53,799	58,778	67,728	55,579
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 41,375	41,102	40,443	39,280	37,337	33,910	27,103	$ 11,719
Cumulative number of reported claims | claim	377
Atrium | Accident Year - 2010
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 3,141
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	45,416	45,960	50,202	51,139	57,182	70,280	76,056
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 39,868	39,294	38,293	35,859	31,653	24,678	$ 11,243
Cumulative number of reported claims | claim	515
Atrium | Accident Year - 2011
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 3,926
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	67,924	69,533	71,744	72,671	86,086	92,093
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 62,515	61,197	57,332	51,288	39,167	$ 16,777
Cumulative number of reported claims | claim	765
Atrium | Accident Year - 2012
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 4,821
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	52,929	55,091	56,729	58,991	71,370
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 43,929	41,677	37,532	31,041	$ 11,059
Cumulative number of reported claims | claim	1,028
Atrium | Accident Year - 2013
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 7,694
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	55,288	59,150	64,243	57,318
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 42,942	39,904	31,669	$ 14,398
Cumulative number of reported claims | claim	1,582
Atrium | Accident Year - 2014
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 14,309
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	63,592	65,737	62,613
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 40,907	33,830	17,359
Cumulative number of reported claims | claim	2,563
Atrium | Accident Year - 2015
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 23,553
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	67,927	63,954
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 29,235	11,874
Cumulative number of reported claims | claim	3,936
Atrium | Accident Year - 2016
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 39,742
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	67,933
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 13,513
Cumulative number of reported claims | claim	3,881
StarStone
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	$ 2,147,213
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	1,465,740
All outstanding liabilities for unpaid losses and LAE prior to 2007, net of reinsurance	1,210
Total outstanding liabilities for unpaid losses and LAE, net of reinsurance	682,683
StarStone | Accident Year - 2007
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	0
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	19,513	17,532	18,453
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 18,807	18,986	18,955
Cumulative number of reported claims | claim	1,254
StarStone | Accident Year - 2008
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 0
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	48,609	48,558	50,984
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 48,734	49,170	48,991
Cumulative number of reported claims | claim	1,715
StarStone | Accident Year - 2009
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 309
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	46,277	39,411	45,340
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 46,146	46,328	46,183
Cumulative number of reported claims | claim	2,253
StarStone | Accident Year - 2010
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 763
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	160,093	158,845	174,838
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 154,101	155,431	145,427
Cumulative number of reported claims | claim	4,247
StarStone | Accident Year - 2011
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 5,067
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	322,684	308,384	324,625
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 310,686	307,799	284,252
Cumulative number of reported claims | claim	8,997
StarStone | Accident Year - 2012
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 18,372
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	329,426	347,626	365,135
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 278,308	260,323	224,506
Cumulative number of reported claims | claim	11,098
StarStone | Accident Year - 2013
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 30,226
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	297,213	308,840	342,406
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 221,989	188,397	141,467
Cumulative number of reported claims | claim	12,414
StarStone | Accident Year - 2014
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 55,291
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	279,432	292,595	248,702
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 163,515	113,340	$ 42,486
Cumulative number of reported claims | claim	15,057
StarStone | Accident Year - 2015
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 96,665
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	372,016	365,426
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 165,701	$ 66,593
Cumulative number of reported claims | claim	21,721
StarStone | Accident Year - 2016
Claims Development [Line Items]
IBNR losses and loss expenses, net of reinsurance	$ 136,314
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Incurred losses and allocated loss adjustment expenses, net of reinsurance	271,950
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 57,753
Cumulative number of reported claims | claim	17,074

Losses and Loss Adjustment E103

Losses and Loss Adjustment Expenses - Reconciliation of Incurred and Paid Loss Development to Liability for Unpaid Losses and LAE (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Fair value adjustments	$ (123,728)	$ (148,325)
Total gross liability for unpaid losses and LAE	5,987,867	5,720,149	$ 4,509,421	$ 4,219,905
Non-life Run-off
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Unallocated loss adjustment expenses	218,336
Fair value adjustments	(135,368)	(163,329)
Gross liability for unpaid losses and LAE before unallocated loss adjustment expenses	4,498,027
Total gross liability for unpaid losses and LAE	4,716,363	4,585,454	3,435,010	4,004,513
Non-life Run-off | General casualty
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liabilities for unpaid losses and allocated LAE, net of reinsurance	505,565
Reinsurance recoverable on unpaid losses	254,017
Unallocated loss adjustment expenses	36,112
Fair value adjustments	(15,622)
Gross liability for unpaid losses and LAE before unallocated loss adjustment expenses	743,960
Total gross liability for unpaid losses and LAE	780,072
Non-life Run-off | Workers' compensation
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liabilities for unpaid losses and allocated LAE, net of reinsurance	1,501,703
Reinsurance recoverable on unpaid losses	592,394
Unallocated loss adjustment expenses	99,718
Fair value adjustments	(39,769)
Gross liability for unpaid losses and LAE before unallocated loss adjustment expenses	2,054,328
Total gross liability for unpaid losses and LAE	2,154,046
Atrium
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liabilities for unpaid losses and allocated LAE, net of reinsurance	169,306
Reinsurance recoverable on unpaid losses	28,191
Unallocated loss adjustment expenses	2,122
Fair value adjustments	12,503	16,491
Total gross liability for unpaid losses and LAE	212,122	201,017	212,611	215,392
StarStone
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liabilities for unpaid losses and allocated LAE, net of reinsurance	682,683
Reinsurance recoverable on unpaid losses	360,737
Unallocated loss adjustment expenses	16,825
Fair value adjustments	(863)	(1,487)
Total gross liability for unpaid losses and LAE	$ 1,059,382	$ 933,678	$ 861,800	$ 0

Losses and Loss Adjustment E104

Losses and Loss Adjustment Expenses - Average Annual Duration of Claims (Details)	Dec. 31, 2016
Non-life Run-off | General casualty
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	12.90%
Year 2	18.60%
Year 3	19.60%
Year 4	13.30%
Year 5	10.60%
Year 6	7.50%
Year 7	5.20%
Year 8	1.70%
Year 9	3.80%
Year 10	0.50%
Non-life Run-off | Workers' compensation
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	19.60%
Year 2	20.40%
Year 3	17.50%
Year 4	10.20%
Year 5	7.00%
Year 6	5.00%
Year 7	3.20%
Year 8	2.50%
Year 9	1.70%
Year 10	2.00%
Atrium
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	23.50%
Year 2	32.10%
Year 3	14.20%
Year 4	7.80%
Year 5	4.60%
Year 6	2.40%
Year 7	2.90%
Year 8	0.70%
Year 9	2.10%
Year 10	1.60%
StarStone
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	18.70%
Year 2	34.70%
Year 3	21.50%
Year 4	9.20%
Year 5	4.40%
Year 6	2.40%
Year 7	0.00%
Year 8	0.00%
Year 9	0.00%
Year 10	0.00%

Losses and Loss Adjustment E105

Losses and Loss Adjustment Expenses - Additional Information (Detail) $ in Thousands	Jan. 01, 2014commutation	Jan. 01, 2013commutation	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)commutation	Dec. 31, 2015USD ($)commutation	Dec. 31, 2014USD ($)commutation	Dec. 31, 2013USD ($)commutation
Effects of Reinsurance [Line Items]
Net incurred losses and loss adjustment expenses			$ 1,321	$ (6,902)	$ 96,462	$ 83,218	$ (64,062)	$ 32,359	$ 65,900	$ 70,136	$ 174,099	$ 104,333	$ 9,146
Net incurred losses and LAE, current period											493,016	476,364	327,817
Net incurred losses and LAE, prior period											(318,917)	(372,031)	(318,671)
Net losses paid, prior period											753,478	681,956	420,715
Non-life Run-off
Effects of Reinsurance [Line Items]
Net incurred losses and loss adjustment expenses											(285,881)	(270,830)	(264,711)
Net incurred losses and LAE, current period											5,829	39,924	24,235
Current period net earned premium											7,100	43,300
Net incurred losses and LAE, prior period											(291,710)	(310,754)	(288,946)
Increase (reduction) in estimates of net ultimate losses, prior period											(259,130)	(227,473)	(235,783)
Increase (reduction) in provisions for bad debt, prior period											(13,822)	(25,271)	(7,700)
Increase (reduction) in provisions for unallocated LAE, prior period											(44,190)	(62,653)	(49,445)
Amortization of fair value adjustments, prior period											25,432	4,643	3,982
Net change in IBNR reserves, prior period											(349,726)	(377,722)	(262,384)	$ 265,200
Net incurred loss development											90,600	150,200	26,600
Amortization of deferred charges, prior period											$ 168,827	$ 15,265	$ 0
Total number of commutations | commutation											56	79	98
Net change in case and LAE reserves, prior period											$ (608,168)	$ (366,262)	$ (285,814)
Net losses paid, prior period											529,937	501,246	312,415
Number of partial commutations of the Company's top 10 ceded recoverables | commutation	1
Number of partial commutations of the Company's top 10 assumed exposures | commutation	2	1												1
Net incurred liabilities settled by way of commutation											14,700	56,600	29,100
Assumed incurred liabilities											24,400	140,300	99,500
Ceded incurred reinsurance recoverables											39,100	83,700	70,400
Estimate of net ultimate liability for asbestos and environmental claims			921,200				356,600				921,200	356,600
Estimate of gross ultimate liability for asbestos and environmental claims			$ 951,100				$ 390,800				951,100	390,800
Non-life Run-off | Asbestos liabilities
Effects of Reinsurance [Line Items]
Net change in IBNR reserves, prior period											39,400	32,000	59,400	$ 69,800
Non-life Run-off | Environmental liabilities
Effects of Reinsurance [Line Items]
Net change in IBNR reserves, prior period											35,500	1,600	6,200	4,900
Non-life Run-off | General casualty liabilities
Effects of Reinsurance [Line Items]
Net change in IBNR reserves, prior period											800	3,000	62,500	42,600
Non-life Run-off | Workers' compensation liabilities
Effects of Reinsurance [Line Items]
Net change in IBNR reserves, prior period											333,200	243,400	63,600	42,100
Non-life Run-off | Other liabilities
Effects of Reinsurance [Line Items]
Net change in IBNR reserves, prior period											90,600	97,700	70,700	$ 105,800
Atrium Segment
Effects of Reinsurance [Line Items]
Net incurred losses and loss adjustment expenses											58,387	47,479	55,428
Net incurred losses and LAE, current period											71,358	69,400	74,094
Net incurred losses and LAE, prior period											(12,971)	(21,921)	(18,666)
Increase (reduction) in estimates of net ultimate losses, prior period											(9,242)	(14,705)	(7,115)
Increase (reduction) in provisions for unallocated LAE, prior period											(421)	(608)	(486)
Amortization of fair value adjustments, prior period											(3,308)	(6,608)	(11,065)
Net change in IBNR reserves, prior period											(20,543)	(27,382)	(18,114)
Net change in case and LAE reserves, prior period											(13,115)	(18,213)	(16,986)
Net losses paid, prior period											24,416	30,890	27,985
StarStone Segment
Effects of Reinsurance [Line Items]
Net incurred losses and loss adjustment expenses											401,593	327,684	218,429
Net incurred losses and LAE, current period											415,829	367,040	229,488
Net incurred losses and LAE, prior period											(14,236)	(39,356)	(11,059)
Increase (reduction) in estimates of net ultimate losses, prior period											(8,730)	(35,138)
Increase (reduction) in provisions for unallocated LAE, prior period											(3,611)	(683)
Amortization of fair value adjustments, prior period											(1,895)	(3,535)
Net change in IBNR reserves, prior period											(156,546)	(200,730)
Net change in case and LAE reserves, prior period											(51,309)	15,772
Net losses paid, prior period											$ 199,125	$ 149,820	$ 80,315
Product Concentration Risk | Liability for Unpaid Claims and Claims Adjustment Expense | Non-life Run-off
Effects of Reinsurance [Line Items]
% of Total											80.00%
Product Concentration Risk | Liability for Unpaid Claims and Claims Adjustment Expense, Net | Non-life Run-off
Effects of Reinsurance [Line Items]
% of Total											77.00%
Segment Concentration Risk | Liability Claims and Claims Adjustment Expense | Atrium Segment
Effects of Reinsurance [Line Items]
% of Total											3.50%
Segment Concentration Risk | Liability Claims and Claims Adjustment Expense | StarStone Segment
Effects of Reinsurance [Line Items]
% of Total											18.00%

Policy Benefits for Life Con106

Policy Benefits for Life Contracts - Schedule of Life and Annuity Benefits (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Insurance [Abstract]
Policy benefits for life contracts	$ 112.1	$ 126.3

Premiums Written and Earned - S

Premiums Written and Earned - Schedule of Net Premiums Written and Earned (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effects of Reinsurance [Line Items]
Gross, premiums written									$ 1,022,340
Net, premiums written									803,936	$ 787,154	$ 547,956
Gross, premiums earned									811,362	857,740	707,170
Ceded, premiums earned									(180,320)	(284,819)	(219,027)
Net, premiums earned	$ 216,188	$ 205,730	$ 208,709	$ 192,887	$ 178,009	$ 209,971	$ 189,344	$ 176,420	823,514	753,744	542,991
Non-life Run-off
Effects of Reinsurance [Line Items]
Gross, premiums written									17,316	38,704	12,818
Ceded, premiums written									(8,114)	(16,110)	(2,546)
Net, premiums written									9,202	22,594	10,272
Gross, premiums earned									25,989	116,494	45,684
Ceded, premiums earned									(9,234)	(72,125)	(14,516)
Net, premiums earned									16,755	44,369	31,168
Atrium
Effects of Reinsurance [Line Items]
Gross, premiums written									143,170	149,082	154,248
Ceded, premiums written									(2,733)	(14,502)	(17,973)
Net, premiums written									140,437	134,580	136,275
Gross, premiums earned									140,438	149,310	153,816
Ceded, premiums earned									(16,022)	(14,635)	(17,871)
Net, premiums earned									124,416	134,675	135,945
StarStone
Effects of Reinsurance [Line Items]
Gross, premiums written									854,699	824,714	512,219
Ceded, premiums written									(206,663)	(196,287)	(113,045)
Net, premiums written									648,036	628,427	399,174
Gross, premiums earned									830,186	769,875	528,135
Ceded, premiums earned									(153,578)	(196,729)	(154,502)
Net, premiums earned									676,608	573,146	373,633
Life and annuities
Effects of Reinsurance [Line Items]
Gross, premiums written									7,155
Net, premiums written									6,261	1,553	2,235
Net, premiums earned									$ 5,735	$ 1,554	$ 2,245

Goodwill, Intangible Assets 108

Goodwill, Intangible Assets and Deferred Charges - Schedule of Goodwill, Intangible Assets and Deferred Charges (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Goodwill, Beginning balance	$ 73,071	$ 73,071
Goodwill, Acquired during the year	0	0
Goodwill, Ending balance	73,071	73,071	$ 73,071
Finite-lived Intangible Assets [Roll Forward]
Intangible assets with a definite life, Beginning balance	31,202	41,048
Intangible assets with a definite life, Acquired during the year	0	0
Intangible assets with a definite life, Amortization	(6,449)	(9,846)
Intangible assets with a definite life, Ending balance	24,753	31,202	41,048
Indefinite-lived Intangible Assets [Roll Forward]
Intangible assets with an indefinite life, Beginning balance	87,031	87,031
Intangible assets with an indefinite life, Acquired during the year	0	0
Intangible assets with an indefinite life, Ending balance	87,031	87,031	87,031
Goodwill and Intangible Assets [Roll Forward]
Goodwill and intangible assets, Beginning Balance	191,304	201,150
Goodwill and intangible assets, Acquired during the year	0	0
Intangible assets with a definite life, Amortization	(6,449)	(9,846)
Goodwill and intangible assets, Ending balance	184,855	191,304	201,150
Movement in Intangible Assets Arising from Insurance Contracts Acquired in Business Combination [Roll Forward]
Intangible assets with a definite life - FVA, Beginning balance	127,170	97,623
Intangible assets with a definite life - FVA, Acquired during the period	37,005	23,968
Intangible assets with a definite life - FVA, Amortization	(19,017)	5,579	9,800
Intangible assets with a definite life - FVA, Ending balance	145,158	127,170	97,623
Deferred Charges [Roll Forward]
Less: deferred charge on retroactive reinsurance	255,911	0	0
Other assets - Deferred Charge, Acquired during the year	7,467	271,176
Other assets - Deferred Charge, Amortization	(168,827)	(15,265)	0
Plus: deferred charge on retroactive reinsurance	$ 94,551	$ 255,911	$ 0

Goodwill, Intangible Assets 109

Goodwill, Intangible Assets and Deferred Charge - Summary of Gross Carrying Value, Accumulated Amortization and Net Carrying Value of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Indefinite-lived Intangible Assets [Line Items]
Intangible assets with an indefinite life, Carrying Value	$ 87,031	$ 87,031	$ 87,031
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value, Fair value adjustments	319,283	280,336
Accumulated Amortization, Fair value adjustments	(174,125)	(153,166)
Net Carrying Value, Fair value adjustments	145,158	127,170	97,623
Gross Carrying Value	42,000	47,000
Accumulated Amortization	(17,247)	(15,798)
Intangible assets with a definite life, Net Carrying Value	24,753	31,202	41,048
Deferred charge on retroactive reinsurance, Gross Carrying Value	278,643	271,176
Deferred charge on retroactive reinsurance, Accumulated Amortization	(184,092)	(15,265)
Deferred charge on retroactive reinsurance, Net Carrying Value	94,551	255,911	$ 0	$ 0
Lloyd’s syndicate capacity
Indefinite-lived Intangible Assets [Line Items]
Intangible assets with an indefinite life, Carrying Value	37,031	37,031
Licenses
Indefinite-lived Intangible Assets [Line Items]
Intangible assets with an indefinite life, Carrying Value	19,900	19,900
Management contract
Indefinite-lived Intangible Assets [Line Items]
Intangible assets with an indefinite life, Carrying Value	30,100	30,100
Losses and LAE liabilities
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value, Fair value adjustments	458,202	456,110
Accumulated Amortization, Fair value adjustments	(334,475)	(307,785)
Net Carrying Value, Fair value adjustments	123,727	148,325
Reinsurance balances recoverable
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value, Fair value adjustments	(175,924)	(175,774)
Accumulated Amortization, Fair value adjustments	160,350	154,619
Net Carrying Value, Fair value adjustments	(15,574)	(21,155)
Other Assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value, Fair value adjustments	(48,840)	0
Accumulated Amortization, Fair value adjustments	0	0
Net Carrying Value, Fair value adjustments	(48,840)	0
Other Liabilities
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value, Fair value adjustments	85,845	0
Accumulated Amortization, Fair value adjustments	0	0
Net Carrying Value, Fair value adjustments	85,845	0
Distribution channel
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	20,000	20,000
Accumulated Amortization	(4,111)	(2,777)
Intangible assets with a definite life, Net Carrying Value	15,889	17,223
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	15,000	15,000
Accumulated Amortization	(10,978)	(6,561)
Intangible assets with a definite life, Net Carrying Value	4,022	8,439
Brand
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	7,000	12,000
Accumulated Amortization	(2,158)	(6,460)
Intangible assets with a definite life, Net Carrying Value	4,842	5,540
Fair value adjustments, policy benefits for life and annuity contracts
Finite-Lived Intangible Assets [Line Items]
Net Carrying Value, Fair value adjustments	$ 46,500	$ 53,600

Goodwill, Intangible Assets 110

Goodwill, Intangible Assets and Deferred Charge - Summary of Estimated Amortization Expense of Intangible Assets (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
2,017	$ 11,531
2,018	10,308
2,019	10,854
2,020	11,409
2,021	11,162
Non-life Run-off
Segment Reporting Information [Line Items]
2,017	9,274
2,018	9,524
2,019	10,178
2,020	10,294
2,021	9,682
Atrium
Segment Reporting Information [Line Items]
2,017	(504)
2,018	469
2,019	1,056
2,020	1,346
2,021	1,620
StarStone
Segment Reporting Information [Line Items]
2,017	2,761
2,018	315
2,019	(380)
2,020	(231)
2,021	$ (140)

Goodwill, Intangible Assets 111

Goodwill, Intangible Assets and Deferred Charge - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Goodwill	$ 73,071,000	$ 73,071,000	$ 73,071,000
Impairment of goodwill	0
Amortization of intangible assets	6,400,000	9,800,000	6,000,000
Impairment of intangible assets with a definite life		4,000,000
Intangible assets FVA amortization (accretion)	19,017,000	(5,579,000)	(9,800,000)
Amortization of deferred charges - related to reduction in liability for losses and LAE	130,200,000	15,300,000
Amortization of deferred charges - primarily related to change in expected return on underlying assets	38,600,000
Intangible assets with a definite life, fair value adjustments	145,158,000	127,170,000	$ 97,623,000
Discontinued operations, held-for-sale | Pavonia
Segment Reporting Information [Line Items]
Intangible assets FVA amortization (accretion)	7,000,000	7,900,000
Fair value adjustments, policy benefits for life and annuity contracts
Segment Reporting Information [Line Items]
Intangible assets with a definite life, fair value adjustments	$ 46,500,000	53,600,000
Minimum
Segment Reporting Information [Line Items]
Intangible assets useful life	4 years
Maximum
Segment Reporting Information [Line Items]
Intangible assets useful life	15 years
Non-life Run-off
Segment Reporting Information [Line Items]
Goodwill	$ 21,200,000	21,200,000
Atrium Segment
Segment Reporting Information [Line Items]
Goodwill	38,900,000	38,900,000
StarStone
Segment Reporting Information [Line Items]
Goodwill	$ 13,000,000	$ 13,000,000

Loans Payable - Amounts of Outs

Loans Payable - Amounts of Outstanding and Accrued Interest (Detail) - USD ($) $ in Thousands	Nov. 18, 2016	Dec. 24, 2014	Sep. 16, 2014	Dec. 31, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Total loans payable				$ 673,603	$ 599,750
Loan facilities | EGL Revolving Credit Facility
Line of Credit Facility [Line Items]
Term			5 years
Total loans payable				535,103	505,750
Loan facilities | Sussex Facility
Line of Credit Facility [Line Items]
Term		4 years
Total loans payable				63,500	94,000
Loan facilities | EGL Term Loan Facility
Line of Credit Facility [Line Items]
Term	3 years
Total loans payable				$ 75,000	$ 0

Loans Payable - Additional Info

Loans Payable - Additional Information (Detail) € in Millions	Nov. 18, 2016USD ($)	Aug. 05, 2016USD ($)	Dec. 24, 2014USD ($)financial_institution	Sep. 16, 2014	Feb. 24, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2016EUR (€)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Feb. 28, 2017USD ($)
Line of Credit Facility [Line Items]
Receipt of loans						$ 571,048,000		$ 657,700,000	$ 70,000,000
Repayment of loans						493,250,000		377,500,000	199,245,000
Currency translation gain (loss)						4,793,000		(24,694,000)	(19,421,000)
Loan facilities
Line of Credit Facility [Line Items]
Receipt of loans						571,000,000
Repayment of loans						493,300,000
Interest expense						20,600,000		19,400,000	$ 12,900,000
Loan facilities | EGL Revolving Credit Facility
Line of Credit Facility [Line Items]
Receipt of loans | €							€ 75
Facility term				5 years
Maximum borrowing capacity		$ 665,000,000
Optional additional commitment		$ 166,250,000
Available unutilized capacity						129,900,000
Frequency of interest payments (at least)		6 months
Covenant compliance, consolidated indebtedness to total capitalization (not greater than)		0.35
Covenant compliance, net income (loss) threshold		$ 1,500,000,000
Covenant compliance, net income threshold percent		50.00%
Covenant compliance, percentage of proceeds of common stock issuance		75.00%
Currency translation gain (loss)						6,000,000
Loan facilities | EGL Revolving Credit Facility | Subsequent event
Line of Credit Facility [Line Items]
Receipt of loans					$ 90,000,000
Repayment of loans					$ 34,000,000
Available unutilized capacity										$ 73,900,000
Loan facilities | Sussex Facility
Line of Credit Facility [Line Items]
Receipt of loans			$ 109,000,000
Repayment of loans						$ 30,500,000		$ 15,000,000
Facility term			4 years
Number of financial institutions | financial_institution			2
Frequency of interest payments (at least)			6 months
Percentage of consideration payable for acquisition			50.00%
Debt instrument, covenant compliance, statutory surplus threshold, multiplier			1.1
Debt instrument, covenant compliance, outstanding loan balance threshold, multiplier			2
Loan facilities | EGL Term Loan Facility
Line of Credit Facility [Line Items]
Facility term	3 years
Maximum borrowing capacity	$ 75,000,000
Frequency of interest payments (at least)	3 months
Debt instrument, covenant compliance, capital resources multiplier for solvency requirements	1.1

Noncontrolling Interests - Rede

Noncontrolling Interests - Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015
Redeemable Noncontrolling Interest [Line Items]
Capital contributions		$ 0	$ 15,728
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Balance at beginning of year		417,663	374,619
Dividends paid		0	(16,128)
Net earnings (loss) attributable to RNCI		40,639	(8,797)
Accumulated other comprehensive income (loss) attributable to RNCI		651	(745)
Transfer from noncontrolling interest		0	15,801
Change in redemption value of RNCI		(4,431)	37,185
Balance at end of year		$ 454,522	$ 417,663
Atrium | Northshore
Redeemable Noncontrolling Interest [Line Items]
Ownership interest held by parent		100.00%
Arden | Northshore
Redeemable Noncontrolling Interest [Line Items]
Ownership interest held by parent		100.00%
Starstone | StarStone Holdings
Redeemable Noncontrolling Interest [Line Items]
Ownership interest held by parent		100.00%
Trident
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Capital contributions	$ 15,700
Trident | North Bay
Redeemable Noncontrolling Interest [Line Items]
Ownership interest held by noncontrolling owners		39.32%
Dowling | North Bay
Redeemable Noncontrolling Interest [Line Items]
Ownership interest held by noncontrolling owners		1.71%

Noncontrolling Interests - Nonc

Noncontrolling Interests - Noncontrolling Interest (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 08, 2015	Dec. 31, 2016	Dec. 31, 2015	Sep. 29, 2015	Sep. 07, 2015
Noncontrolling Interest [Line Items]
Noncontrolling interest			$ 8,520	$ 3,911
JCF II Funds
Noncontrolling Interest [Line Items]
Noncontrolling interest					$ 182,800
Purchase of noncontrolling shareholders' interest in subsidiaries	$ 140,000
Shinsei
Noncontrolling Interest [Line Items]
Noncontrolling interest						$ 12,500
Purchase of noncontrolling shareholders' interest in subsidiaries		$ 10,400

Share Capital (Detail)

Share Capital (Detail)	1 Months Ended	2 Months Ended	12 Months Ended
	Dec. 31, 2016vote$ / sharesshares	Feb. 24, 2017shares	Dec. 31, 2015$ / sharesshares	Dec. 31, 2014$ / sharesshares	Jul. 08, 2013$ / shares
Class of Stock [Line Items]
Common shares, authorized (shares)	111,000,000		111,000,000
Common shares, par value (dollars per share) | $ / shares	$ 1		$ 1
Preference shares, authorized (shares)	45,000,000		45,000,000
Preferred shares, par value (dollars per share) | $ / shares	$ 1		$ 1
Warrants exercised (shares)	164,919
Voting ordinary shares
Class of Stock [Line Items]
Common shares, par value (dollars per share) | $ / shares	$ 1		$ 1		$ 1
Common stock, number of votes | vote	1
Percentage ownership (or more) of voting ordinary shares entitled to less than one vote per share	9.50%
Ordinary shares, issued (shares)	16,175,250		16,133,334
Ordinary shares, outstanding (shares)	16,175,250		16,133,334
Series C non-voting convertible ordinary shares
Class of Stock [Line Items]
Conversion ratio, issued upon conversion (shares)	1
Aggregate voting power of Company's issued share capital (percent) (not to exceed)	0.01%
Ordinary shares, issued (shares)	2,792,157		2,725,637
Ordinary shares, outstanding (shares)	2,792,157		2,725,637
Warrants outstanding (shares)	175,901
Warrants, exercise price (dollars per share) | $ / shares	$ 115
Stock issued upon exercise of Warrants (shares)	66,520
Series B non-voting convertible ordinary shares
Class of Stock [Line Items]
Ordinary shares, issued (shares)	0
Ordinary shares, outstanding (shares)	0
Series D non-voting convertible ordinary shares
Class of Stock [Line Items]
Ordinary shares, issued (shares)	0
Ordinary shares, outstanding (shares)	0
Series E non-voting convertible ordinary shares
Class of Stock [Line Items]
Ordinary shares, issued (shares)	404,771		404,771	714,015
Ordinary shares, outstanding (shares)	404,771		404,771	714,015,000
Conversion of stock, shares converted (shares)			309,244
Non-voting ordinary shares
Class of Stock [Line Items]
Common shares, par value (dollars per share) | $ / shares	$ 1		$ 1
Series C non-voting preferred shares
Class of Stock [Line Items]
Preferred shares, issued (shares)	388,571		0
Preferred shares, liquidation preference (dollars per share) | $ / shares	$ 0.001
Series B non-voting preferred shares
Class of Stock [Line Items]
Preferred shares, par value (dollars per share) | $ / shares				$ 1
Stock issued upon conversion (shares)				(714,015,000)
Issuance of stock (shares)				714,015
Subsequent event
Class of Stock [Line Items]
Stock issued upon conversion (shares)		192,485

Earnings Per Share - Comparison

Earnings Per Share - Comparison of Basic and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net earnings from continuing operations									$ 252,844	$ 222,322	$ 208,210
Net earnings (losses) from discontinuing operations									11,963	(2,031)	5,539
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED	$ 22,645	$ 156,048	$ 40,594	$ 45,520	$ 111,857	$ 49,042	$ 14,545	$ 44,847	$ 264,807	$ 220,291	$ 213,749
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average ordinary shares outstanding - basic (shares)									19,299,426	19,252,072	18,409,069
Effect of dilutive securities:
Warrants (in shares)									99,387	78,883	58,957
Preferred shares (shares)									0	0	136,934
Weighted average ordinary shares outstanding - diluted (shares)									19,447,241	19,407,756	18,678,130
Basic:
Net earnings from continuing operations (dollars per share)	$ 0.91	$ 7.86	$ 1.99	$ 2.34	$ 5.91	$ 2.57	$ 0.99	$ 2.04	$ 13.10	$ 11.55	$ 11.31
Net earnings (loss) from discontinuing operations (dollars per share)	0.26	0.23	0.11	0.02	(0.11)	(0.02)	(0.23)	0.29	0.62	(0.11)	0.30
Net earnings per ordinary share (dollars per share)	1.17	8.09	2.10	2.36	5.80	2.55	0.76	2.33	13.72	11.44	11.61
Diluted:
Net earnings from continuing operations (dollars per share)	0.90	7.79	1.98	2.33	5.86	2.55	0.98	2.03	13	11.46	11.15
Net earnings (loss) from discontinuing operations (dollars per share)	0.26	0.23	0.11	0.02	(0.11)	(0.02)	(0.23)	0.29	0.62	(0.11)	0.29
Net earnings per ordinary share (dollars per share)	$ 1.16	$ 8.02	$ 2.09	$ 2.35	$ 5.75	$ 2.53	$ 0.75	$ 2.32	$ 13.62	$ 11.35	$ 11.44
Restricted shares
Effect of dilutive securities:
Shares (in shares)									31,434	63,900	57,184
Restricted share units
Effect of dilutive securities:
Shares (in shares)									16,994	12,901	15,986

Share-Based Compensation and118

Share-Based Compensation and Pensions - Restricted Shares and Restricted Share Units (Detail) - Restricted shares and restricted share awards - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Shares, Nonvested - January 1 (shares)	96,055
Number of Shares, Granted (shares)	44,165
Number of Shares, Vested (shares)	(44,925)
Number of Shares, Forfeited (shares)	(16,303)
Number of Shares, Nonvested - December 31 (shares)	78,992	96,055
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Fair Value of the Award, Nonvested - January 1 (dollars per share)	$ 150.04
Weighted Average Fair Value of the Award, Granted (dollars per share)	182.98
Weighted Average Fair Value of the Award, Vested (dollars per share)	101.48
Weighted Average Fair Value of the Award, Forfeited (dollars per share)	141.09
Weighted Average Fair Value of the Award, Nonvested - December 31 (dollars per share)	$ 165.94	$ 150.04
Compensation costs	$ 3	$ 6.1	$ 3.9
Unrecognized compensation cost	$ 8.4
Unrecognized compensation cost, period of recognition	2 years
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

Share-Based Compensation and119

Share-Based Compensation and Pensions - Cash-Settled Stock Appreciation Rights (Detail) - Cash-Settled Stock Appreciation Rights - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance, beginning of year, Number of SARs (shares)	1,160,828
Exercised, Number of SARs (shares)	(92,458)
Forfeited, Number of SARs (shares)	(127,202)
Balance, end of year, Number of SARs (shares)	941,168	1,160,828
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Balance, beginning of year, Weighted Average Exercise Price of SARs (dollars per share)	$ 140.51
Exercised, Weighted Average Exercise Price of SARS (dollars per share)	139.88
Forfeited, Weighted Average Exercise Price of SARs (dollars per share)	139.58
Balance, end of year, Weighted Average Exercise Price of SARs (dollars per share)	$ 140.70	$ 140.51
Balance, end of year, Weighted Average Remaining Contractual Term (in years)	1 year 11 months 9 days
Balance, end of year, Aggregate Intrinsic Value	$ 53,644
Closing price per share, ordinary shares (dollars per share)	$ 197.70
Compensation costs	$ 35,600	$ 8,900
Unrecognized compensation cost	$ 10,100
Unrecognized compensation cost, period of recognition	6 months 11 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Weighted average fair value per SAR (dollars per share)	$ 62.39	$ 29.02	$ 37.63
Weighted-average volatility	19.82%	22.08%	21.24%
Weighted-average risk-free interest rate	1.12%	1.29%	0.81%
Dividend yield	0.00%	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise period	4 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise period	10 years

Share-Based Compensation and120

Share-Based Compensation and Pensions - Performance Share Units (Details) - Performance share units - Subsequent event $ in Millions	2 Months Ended
	Feb. 24, 2017USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted (shares) | shares	34,775
Grant date fair value | $	$ 6.9
Vesting period	3 years
Performance Target One | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage increase in fully diluted book value per share	30.00%
Share settlement percentage	100.00%
Performance Target One | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage increase in fully diluted book value per share	40.00%
Share settlement percentage	150.00%
Performance Target Two | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage increase in fully diluted book value per share	20.00%
Share settlement percentage	50.00%
Performance Target Two | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage increase in fully diluted book value per share	30.00%
Share settlement percentage	100.00%
Performance Target Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage increase in fully diluted book value per share	20.00%
Share settlement percentage	0.00%

Share-Based Compensation and121

Share-Based Compensation and Pensions - Other Share-Based Compensation Plans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)directorshares	Dec. 31, 2014USD ($)directorshares
Long-term incentive plans | Time-based restricted shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation costs | $	$ 2.8	$ 3.9	$ 5.2
Unrecognized compensation cost | $	$ 3.7
Unrecognized compensation cost, period of recognition	1 year 9 months 4 days
Long-term incentive plans | Minimum | Time-based restricted shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period	2 years
Long-term incentive plans | Maximum | Time-based restricted shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period	3 years
Deferred compensation plan | Director | Restricted share units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Restricted share units credited to the accounts of non-employee directors (shares) | shares	4,298	5,174	3,716
Expenses related to the restricted share units | $	$ 0.7	$ 1	$ 0.5
Deferred compensation plan | Director | Restricted share units | Restricted share units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Deferred compensation arrangement, shares converted | shares		2,393	11,749
Number of directors | director		2
Previous deferred compensation plan | Director | Restricted share units | Restricted share units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Deferred compensation arrangement, shares converted | shares			14,922
Number of directors | director			1
Employee share purchase plan | Employee stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation costs | $	$ 0.3	$ 0.3	$ 0.1
Stock issued to employees (shares) | shares	12,234	11,998	6,031

Share-Based Compensation and122

Share-Based Compensation and Pensions - Pension Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense	$ 10.8	$ 10.3	$ 9.2
Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension expense	2.3	0.6	$ 0.5
Unfunded liability	10.3	12.1
Accrued liability	$ 10.3	$ 12.1

Taxation - Additional Informati

Taxation - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Bermuda income taxes at statutory rate	0.00%	0.00%	0.00%
Valuation allowance	$ 290,861,000	$ 291,280,000
Increase (decrease) in valuation allowance	(400,000)
Reversal of accrued interest and penalties related to unrecognized tax benefits	0	0	$ 2,200,000
Accrued interest and penalties related to unrecognized tax benefits	$ 0	$ 0	$ 0

Taxation - Earnings before Inco

Taxation - Earnings before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Domestic (Bermuda)									$ 191,647	$ 61,695	$ 154,453
Foreign									135,677	163,327	72,845
EARNINGS BEFORE INCOME TAXES	$ 35,395	$ 174,707	$ 55,453	$ 61,769	$ 78,745	$ 59,516	$ 30,173	$ 56,588	$ 327,324	$ 225,022	$ 227,298

Taxation - Tax Expense for Inco

Taxation - Tax Expense for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Domestic (Bermuda)									$ 0	$ 0	$ 0
Foreign									21,485	30,028	38,814
Total current tax expense									21,485	30,028	38,814
Deferred:
Domestic (Bermuda)									0	0	0
Foreign									13,389	(17,378)	(33,213)
Total deferred tax expense									13,389	(17,378)	(33,213)
Total tax expense on continuing operations	$ 11,228	$ 8,227	$ 8,050	$ 7,369	$ (15,794)	$ 12,684	$ 8,087	$ 7,673	$ 34,874	$ 12,650	$ 5,601

Taxation - Reconciliation of Ea

Taxation - Reconciliation of Earnings before Income Taxes Computed by Applying Effective Rate (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Earnings before income tax	$ 35,395	$ 174,707	$ 55,453	$ 61,769	$ 78,745	$ 59,516	$ 30,173	$ 56,588	$ 327,324	$ 225,022	$ 227,298
Bermuda income taxes at statutory rate									0.00%	0.00%	0.00%
Foreign income tax rate differential									8.80%	17.60%	11.30%
Change in unrecognized tax benefits									0.00%	0.00%	(1.00%)
Benefit of loss carryovers									(0.00%)		(1.30%)
Change in valuation allowance									(0.10%)	(10.50%)	(13.20%)
Investment write-off									0.00%		1.90%
Foreign currency translation									0.00%	(0.30%)	0.80%
Other									2.00%	(1.20%)	4.00%
Effective tax rate									10.70%	5.60%	2.50%

Taxation - Components of Deferr

Taxation - Components of Deferred Tax Assets and Deferred Tax Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Net operating loss carryforwards	$ 262,271	$ 259,851
Tax credits and other carryforwards	7,487	6,354
Insurance reserves	19,265	29,682
Unearned premiums	8,760	6,821
Lloyd's underwriting losses taxable in future periods	6,581	17,768
Provisions for bad debt	16,018	17,694
Other deferred tax assets	7,946	3,532
Gross deferred tax assets	328,328	341,702
Valuation allowance	(290,861)	(291,280)
Deferred tax assets	37,467	50,422
Deferred tax liabilities:
Unrealized gains on investments	(12,804)	(10,567)
Intangible assets	(20,615)	(20,895)
Other deferred tax liabilities	(21,030)	(22,044)
Deferred tax liabilities	(54,449)	(53,506)
Net deferred tax liability	$ (16,982)	$ (3,084)

Taxation - Net Operating Loss C

Taxation - Net Operating Loss Carryforwards (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Tax effect of operating loss carryforward	$ 262,271	$ 259,851
Foreign Tax Authority | United States
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	571,235
Tax effect of operating loss carryforward	193,670
Tax effect of alternative minimum tax credit	7,374
Foreign Tax Authority | United Kingdom
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	280,707
Tax effect of operating loss carryforward	57,381
Foreign Tax Authority | Other
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	30,098
Tax effect of operating loss carryforward	6,152
Capital loss carryforward | Foreign Tax Authority | United States
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	11,820
Tax effect of capital loss carryforward	$ 4,905

Taxation - Reconciliation of Be

Taxation - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning of year	$ 0	$ 0	$ 2,249
Gross increases — tax positions related to prior years	0	0	0
Gross decreases — tax positions related to prior years	0	0	0
Lapse of statute of limitations	0	0	(2,249)
Balance, end of year	$ 0	$ 0	$ 0

Related Party Transactions - St

Related Party Transactions - Stone Point Capital LLC (Details) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Jul. 31, 2012shares	Dec. 31, 2016USD ($)Investment	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Nov. 06, 2013general_partner
Related Party Transaction [Line Items]
Redeemable noncontrolling interest	$ 454,522				$ 417,663					$ 454,522	$ 417,663	$ 374,619
Investments in funds	937,047				980,289					937,047	980,289
Investment in registered investment company	95,047				111,495					95,047	111,495
Net realized and unrealized gains (losses)	(61,570)	$ 66,608	$ 34,503	$ 38,277	(56,705)	$ (15,835)	$ (8,296)	$ 39,313		77,818	(41,523)	$ 51,991
Affiliated entity
Related Party Transaction [Line Items]
Investments in funds	347,000									347,000
Sound Point Capital
Related Party Transaction [Line Items]
Separate account assets	$ 61,200				53,500					$ 61,200	53,500
Trident | Affiliated entity
Related Party Transaction [Line Items]
Voting ordinary shares acquired (shares) | shares									1,350,000
Voting ordinary shares acquired, percent	8.30%									8.30%
Number of newly elected board of directors | general_partner													1
Number of general partners | general_partner													4
Agreement period										90 days
Redeemable noncontrolling interest, redemption period one										5 years
Redeemable noncontrolling interest, redemption period two										7 years
Redeemable noncontrolling interest	$ 454,500				417,700					$ 454,500	417,700
Investments in funds	232,100				237,900					232,100	237,900
Investment in registered investment company	20,900				21,000					20,900	21,000
Trident | Affiliated entity | Fund Investments
Related Party Transaction [Line Items]
Net realized and unrealized gains (losses)										17,200	(100)
Trident | Affiliated entity | Registered Investment Company
Related Party Transaction [Line Items]
Net realized and unrealized gains (losses)										(400)	(4,700)
Interest income										3,100	2,800
Eagle Point Credit and PRIMA Capital Advisors | Affiliated entity
Related Party Transaction [Line Items]
Separate account assets	215,000				157,800					215,000	157,800
Eagle Point Credit and PRIMA Capital Advisors | Affiliated entity | Management fees
Related Party Transaction [Line Items]
Management fees										500	400
Sound Point Capital | Affiliated entity
Related Party Transaction [Line Items]
Investments in funds	25,400				34,500					25,400	34,500
Net realized and unrealized gains (losses)										$ 1,900	600
Number of invested funds | Investment										2
Sound Point Capital | Affiliated entity | Management fees
Related Party Transaction [Line Items]
Management fees										$ 300	100
CLO equities
Related Party Transaction [Line Items]
Investments in funds	61,565				61,702					61,565	61,702
CLO equities | Sound Point Capital | Affiliated entity
Related Party Transaction [Line Items]
Investments in funds	$ 20,300				$ 18,200					20,300	18,200
Net realized and unrealized gains (losses)										2,100	(3,600)
Interest income										$ 6,700	$ 3,400

Related Party Transactions - Go

Related Party Transactions - Goldman Sachs & Co. (Details)	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)Company	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)Company	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)Company	Dec. 31, 2015USD ($)Company	Dec. 31, 2014USD ($)
Related Party Transaction [Line Items]
Investments in funds	$ 937,047,000				$ 980,289,000				$ 937,047,000	$ 980,289,000
Net realized and unrealized gains (losses)	(61,570,000)	$ 66,608,000	$ 34,503,000	$ 38,277,000	$ (56,705,000)	$ (15,835,000)	$ (8,296,000)	$ 39,313,000	77,818,000	$ (41,523,000)	$ 51,991,000
Affiliated entity
Related Party Transaction [Line Items]
Investments in funds	$ 347,000,000								$ 347,000,000
Goldman Sachs | Affiliated entity
Related Party Transaction [Line Items]
Ownership percentage of ordinary shares					4.10%					4.10%
Economic ownership percentage	2.30%	8.50%			17.50%				2.30%	17.50%
Investments in funds	$ 19,300,000				$ 39,600,000				$ 19,300,000	$ 39,600,000
Net realized and unrealized gains (losses)									20,600,000	24,100,000
Interest income									1,700,000	0
Separate account assets	$ 748,000,000				$ 758,900,000				748,000,000	758,900,000
Goldman Sachs | Affiliated entity | Management fees
Related Party Transaction [Line Items]
Management fees									$ 800,000	$ 600,000
Hastings Insurance Group Limited | Affiliated entity
Related Party Transaction [Line Items]
Indirect non-voting investments in number of companies | Company	2				2				2	2
Investment in indirect non-voting interests of affiliated companies	$ 49,900,000				$ 44,600,000				$ 49,900,000	$ 44,600,000
Series C non-voting convertible ordinary shares | Goldman Sachs | Affiliated entity
Related Party Transaction [Line Items]
Ownership percentage of ordinary shares					100.00%					100.00%
Hastings companies | Goldman Sachs affiliates
Related Party Transaction [Line Items]
Equity method investment ownership percentage	38.00%								38.00%

Related Party Transactions - CP

Related Party Transactions - CPPIB (Details) - USD ($) $ in Millions	Dec. 31, 2016	Nov. 30, 2016	May 05, 2015
CPPIB and Management of Wilton Re | Affiliated entity
Related Party Transaction [Line Items]
Ownership percentage of ordinary shares		9.30%
Economic ownership percentage		16.00%
Reinsurance balances recoverable	$ 9.4
CPPIB Epsilon Ontario Limited Partnership | Affiliated entity
Related Party Transaction [Line Items]
Ownership percentage of ordinary shares	4.60%
Economic ownership percentage	3.80%
Wilton Re | CPPIB and Management of Wilton Re
Related Party Transaction [Line Items]
Ownership interest held by parent	100.00%		100.00%

Related Party Transactions - Ka

Related Party Transactions - KaylaRe (Details) $ / shares in Units, $ in Thousands	Dec. 15, 2016USD ($)	Dec. 31, 2016USD ($)member$ / sharesshares	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)member$ / sharesshares	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Related Party Transaction [Line Items]
Ceded, premiums earned										$ 180,320	$ 284,819	$ 219,027
Net incurred losses and LAE		$ 1,321	$ (6,902)	$ 96,462	$ 83,218	$ (64,062)	$ 32,359	$ 65,900	$ 70,136	174,099	104,333	9,146
Acquisition costs		47,619	$ 50,074	$ 43,847	$ 45,029	53,666	$ 44,445	$ 33,781	$ 31,824	186,569	163,716	$ 117,542
Reinsurance recoverable		1,460,743				1,451,921				1,460,743	1,451,921
Reinsurance balances payable		394,021				$ 271,801				$ 394,021	$ 271,801
KaylaRe
Related Party Transaction [Line Items]
Initial capital raise	$ 620,000
KaylaRe | Starstone
Related Party Transaction [Line Items]
Percentage reinsured of certain businesses										35.00%
Ceded, premiums earned										$ 117,600
Net incurred losses and LAE										75,700
Acquisition costs										42,500
KaylaRe | Subsidiaries
Related Party Transaction [Line Items]
Ceded reinsurance receivables		$ 177,200								$ 177,200
Equity method investee | KaylaRe
Related Party Transaction [Line Items]
Warrants to purchase common shares, up to (shares) | shares		900,000								900,000
Warrants, exercise price (dollars per share) | $ / shares		$ 20								$ 20
Shareholders Agreement, right to appoint board members, number of members | member		1								1
Shareholders Agreement, minimum number of shares owned for right to appoint board members | shares		1,250,000								1,250,000
Shareholders Agreement, lock-up period on common shares	5 years
Reinsurance recoverable		$ 242,100								$ 242,100
Ceded unearned premium		109,000								109,000
Funds held		182,300								182,300
Reinsurance balances payable		132,600								132,600
Ceded acquisition costs		$ 41,200								$ 41,200
KaylaRe
Related Party Transaction [Line Items]
Equity method investment ownership percentage		48.40%								48.40%
Equity method investment		$ 294,600								$ 294,600
Net incurred losses and LAE										$ 1,400

Related Party Transactions - Hi

Related Party Transactions - Hillhouse (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Investments in funds	$ 937,047	$ 980,289
Affiliated entity
Related Party Transaction [Line Items]
Investments in funds	$ 347,000
Hillhouse affiliates | Affiliated entity
Related Party Transaction [Line Items]
Ownership percentage of ordinary shares	2.10%
Economic ownership percentage	9.80%
Hillhouse | KaylaRe | Affiliated entity
Related Party Transaction [Line Items]
Investments in funds	$ 350,000

Dividend Restrictions and St135

Dividend Restrictions and Statutory Financial Information - Summary of Statutory Capital and Surplus (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Bermuda
Statutory Accounting Practices [Line Items]
Minimum required statutory capital and surplus	$ 622,183	$ 510,773
Actual statutory capital and surplus	2,131,308	1,767,172
Statutory income	339,548	147,883	$ 41,750
United Kingdom
Statutory Accounting Practices [Line Items]
Minimum required statutory capital and surplus	532,132	61,819
Actual statutory capital and surplus	805,170	629,208
Statutory income	131,619	113,296	107,030
United States
Statutory Accounting Practices [Line Items]
Minimum required statutory capital and surplus	209,283	147,538
Actual statutory capital and surplus	662,942	756,543
Statutory income	(1,439)	14,964	91,576
Europe
Statutory Accounting Practices [Line Items]
Minimum required statutory capital and surplus	240,107	44,126
Actual statutory capital and surplus	286,039	211,458
Statutory income	$ 31,075	$ 1,856	$ 11,959

Dividend Restrictions and St136

Dividend Restrictions and Statutory Financial Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016USD ($)syndicate	Dec. 31, 2015USD ($)
Statutory Accounting Practices [Line Items]
Restricted net assets of consolidated subsidiaries	$ 1,600,000,000
Number of syndicates | syndicate	3
Bermuda
Statutory Accounting Practices [Line Items]
Target statutory capital and surplus percent	120.00%
Minimum liquidity ratio percent (not less than)	75.00%
Maximum percentage reduction in total statutory capital without prior approval of Bermuda regulator (percent) (or more)	15.00%
Minimum solvency requirement	$ 1,500,000,000	$ 1,260,000,000
United Kingdom
Statutory Accounting Practices [Line Items]
Minimum capital requirements	273,000,000	567,400,000
United States
Statutory Accounting Practices [Line Items]
Minimum levels of risk-based capital	402,000,000	528,300,000
United States and Canada
Statutory Accounting Practices [Line Items]
Minimum levels of risk-based capital	51,600,000	80,800,000
Maximum dividend payout without prior approval	0	500,000
Switzerland
Statutory Accounting Practices [Line Items]
Minimum Swiss solvency test margin	6,100,000	94,800,000
Liechtenstein
Statutory Accounting Practices [Line Items]
Minimum solvency requirement	$ 12,800,000	$ 20,400,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Rent expense	$ 9,700	$ 11,100	$ 10,200
Commitments, unfunded	144,000
Concentration Risk [Line Items]
Funds held by reinsured companies	82,073	92,798
Guarantor Obligations [Line Items]
Collateral for line of credit facility	122,000
Limited parental guarantee
Guarantor Obligations [Line Items]
Total parental guarantees	625,700	$ 334,200
Reinsurer concentration risk | Reinsurance balances recoverable
Concentration Risk [Line Items]
Funds held by reinsured companies	1,000,000
Dana Companies
Business Acquisition [Line Items]
Loss contingency accrual	220,500
Accrual for environmental liabilities	2,300
Insurance recoveries receivable	$ 133,000

Commitments and Contingencie138

Commitments and Contingencies - Schedule of Future Minimum Rental Payments on Non-Cancellable Leases (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,017	$ 10,022
2,018	9,510
2,019	7,752
2,020	6,183
2,021	4,147
2022 and beyond	8,170
Total	$ 45,784

Segment Information - Additiona

Segment Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016Segment
Segment Reporting [Abstract]
Number of segments	4

Segment Information - Summary o

Segment Information - Summary of Operations by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INCOME
Net premiums earned	$ 216,188	$ 205,730	$ 208,709	$ 192,887	$ 178,009	$ 209,971	$ 189,344	$ 176,420	$ 823,514	$ 753,744	$ 542,991
Fees and commission income	13,266	9,187	10,487	6,424	7,450	9,708	10,125	12,064	39,364	39,347	34,919
Net investment income	42,229	48,022	44,932	50,280	44,265	31,640	25,265	21,394	185,463	122,564	66,024
Net realized and unrealized gains (losses)	(61,570)	66,608	34,503	38,277	(56,705)	(15,835)	(8,296)	39,313	77,818	(41,523)	51,991
Other income	(1,277)	414	3,289	2,410	12,648	2,370	11,833	3,477	4,836	30,328	14,149
Total income	208,836	329,961	301,920	290,278	185,667	237,854	228,271	252,668	1,130,995	904,460	710,074
EXPENSES
Net incurred losses and LAE	1,321	(6,902)	96,462	83,218	(64,062)	32,359	65,900	70,136	174,099	104,333	9,146
Life and annuity policy benefits	(2,265)	1,682	(1,613)	158	(1,808)	401	407	454	(2,038)	(546)	84
Acquisition costs	47,619	50,074	43,847	45,029	53,666	44,445	33,781	31,824	186,569	163,716	117,542
General and administrative expenses	123,497	103,097	104,206	92,934	106,754	96,818	90,837	94,750	423,734	389,159	337,120
Interest expense	4,796	5,027	5,421	5,398	5,368	5,156	4,876	4,003	20,642	19,403	12,922
Net foreign exchange losses (gains)	(1,527)	2,276	(1,856)	1,772	7,004	(841)	2,297	(5,087)	665	3,373	5,962
Total expenses	173,441	155,254	246,467	228,509	106,922	178,338	198,098	196,080	803,671	679,438	482,776
Earnings before income tax	35,395	174,707	55,453	61,769	78,745	59,516	30,173	56,588	327,324	225,022	227,298
INCOME TAXES	(11,228)	(8,227)	(8,050)	(7,369)	15,794	(12,684)	(8,087)	(7,673)	(34,874)	(12,650)	(5,601)
NET EARNINGS FROM CONTINUING OPERATIONS	24,167	166,480	47,403	54,400	94,539	46,832	22,086	48,915	292,450	212,372	221,697
NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE	5,483	3,897	2,378	205	(1,898)	(831)	(3,879)	4,577	11,963	(2,031)	5,539
Less: Net loss (earnings) attributable to noncontrolling interest	(7,005)	(14,329)	(9,187)	(9,085)	19,216	3,041	(3,662)	(8,645)	(39,606)	9,950	(13,487)
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED	$ 22,645	$ 156,048	$ 40,594	$ 45,520	$ 111,857	$ 49,042	$ 14,545	$ 44,847	264,807	220,291	213,749
Non-life Run-off
INCOME
Net premiums earned									16,755	44,369	31,168
EXPENSES
Net incurred losses and LAE									(285,881)	(270,830)	(264,711)
Atrium
INCOME
Net premiums earned									124,416	134,675	135,945
EXPENSES
Net incurred losses and LAE									58,387	47,479	55,428
StarStone
INCOME
Net premiums earned									676,608	573,146	373,633
EXPENSES
Net incurred losses and LAE									401,593	327,684	218,429
Life and annuities
INCOME
Net premiums earned									5,735	1,554	2,245
Operating Segments | Non-life Run-off
INCOME
Net premiums earned									16,755	44,369	31,168
Fees and commission income									25,324	21,366	19,342
Net investment income									143,783	84,185	57,899
Net realized and unrealized gains (losses)									77,689	(31,193)	48,030
Other income									4,003	29,293	13,310
Total income									267,554	148,020	169,749
EXPENSES
Net incurred losses and LAE									(285,881)	(270,830)	(264,711)
Life and annuity policy benefits									0	0	0
Acquisition costs									4,198	8,860	8,393
General and administrative expenses									275,199	238,989	198,063
Interest expense									22,863	14,565	7,493
Net foreign exchange losses (gains)									(1,678)	4,372	8,015
Total expenses									14,701	(4,044)	(42,747)
Earnings before income tax									252,853	152,064	212,496
INCOME TAXES									(28,577)	(12,570)	622
NET EARNINGS FROM CONTINUING OPERATIONS									224,276	139,494	213,118
NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE									0	0	0
Less: Net loss (earnings) attributable to noncontrolling interest									(17,600)	33,722	(9,836)
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									206,676	173,216	203,282
Operating Segments | Atrium
INCOME
Net premiums earned									124,416	134,675	135,945
Fees and commission income									18,189	28,352	26,176
Net investment income									2,940	2,225	1,748
Net realized and unrealized gains (losses)									(601)	252	41
Other income									206	359	223
Total income									145,150	165,863	164,133
EXPENSES
Net incurred losses and LAE									58,387	47,479	55,428
Life and annuity policy benefits									0	0	0
Acquisition costs									44,670	45,509	43,417
General and administrative expenses									25,132	31,610	34,921
Interest expense									198	4,264	5,429
Net foreign exchange losses (gains)									3,310	213	(1,559)
Total expenses									131,697	129,075	137,636
Earnings before income tax									13,453	36,788	26,497
INCOME TAXES									(2,573)	(5,968)	(5,092)
NET EARNINGS FROM CONTINUING OPERATIONS									10,880	30,820	21,405
NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE									0	0	0
Less: Net loss (earnings) attributable to noncontrolling interest									(4,464)	(14,262)	(10,974)
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									6,416	16,558	10,431
Operating Segments | StarStone
INCOME
Net premiums earned									676,608	573,146	373,633
Fees and commission income									5,102	0	0
Net investment income									22,221	15,937	5,321
Net realized and unrealized gains (losses)									5,728	(9,784)	2,136
Other income									1,780	676	616
Total income									711,439	579,975	381,706
EXPENSES
Net incurred losses and LAE									401,593	327,684	218,429
Life and annuity policy benefits									0	0	0
Acquisition costs									138,822	109,347	65,734
General and administrative expenses									125,279	126,132	113,344
Interest expense									47	6	0
Net foreign exchange losses (gains)									(754)	(480)	945
Total expenses									664,987	562,689	398,452
Earnings before income tax									46,452	17,286	(16,746)
INCOME TAXES									(3,693)	5,888	(1,130)
NET EARNINGS FROM CONTINUING OPERATIONS									42,759	23,174	(17,876)
NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE									0	0	0
Less: Net loss (earnings) attributable to noncontrolling interest									(17,542)	(9,510)	7,323
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									25,217	13,664	(10,553)
Operating Segments | Life and annuities
INCOME
Net premiums earned									5,735	1,554	2,245
Fees and commission income									0	0	32
Net investment income									20,043	21,137	1,056
Net realized and unrealized gains (losses)									(4,998)	(798)	1,784
Other income									353	0	0
Total income									21,133	21,893	5,117
EXPENSES
Net incurred losses and LAE									0	0	0
Life and annuity policy benefits									(2,038)	(546)	84
Acquisition costs									612	0	(2)
General and administrative expenses									7,148	2,799	1,423
Interest expense									1,058	1,488	0
Net foreign exchange losses (gains)									(213)	(732)	(1,439)
Total expenses									6,567	3,009	66
Earnings before income tax									14,566	18,884	5,051
INCOME TAXES									(31)	0	(1)
NET EARNINGS FROM CONTINUING OPERATIONS									14,535	18,884	5,050
NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE									11,963	(2,031)	5,539
Less: Net loss (earnings) attributable to noncontrolling interest									0	0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									26,498	16,853	10,589
Eliminations
INCOME
Net premiums earned									0	0	0
Fees and commission income									(9,251)	(10,371)	(10,631)
Net investment income									(3,524)	(920)	0
Net realized and unrealized gains (losses)									0	0	0
Other income									(1,506)	0	0
Total income									(14,281)	(11,291)	(10,631)
EXPENSES
Net incurred losses and LAE									0	0	0
Life and annuity policy benefits									0	0	0
Acquisition costs									(1,733)	0	0
General and administrative expenses									(9,024)	(10,371)	(10,631)
Interest expense									(3,524)	(920)	0
Net foreign exchange losses (gains)									0	0	0
Total expenses									(14,281)	(11,291)	(10,631)
Earnings before income tax									0	0	0
INCOME TAXES									0	0	0
NET EARNINGS FROM CONTINUING OPERATIONS									0	0	0
NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE									0	0	0
Less: Net loss (earnings) attributable to noncontrolling interest									0	0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									$ 0	$ 0	$ 0

Segment Information - Gross Pre

Segment Information - Gross Premiums Written by Geographical Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Gross, premiums written	$ 1,022,340
Non-life Run-off
Segment Reporting Information [Line Items]
Gross, premiums written	17,316	$ 38,704	$ 12,818
Atrium
Segment Reporting Information [Line Items]
Gross, premiums written	143,170	149,082	154,248
StarStone
Segment Reporting Information [Line Items]
Gross, premiums written	854,699	$ 824,714	$ 512,219
Life and annuities
Segment Reporting Information [Line Items]
Gross, premiums written	7,155
United States
Segment Reporting Information [Line Items]
Gross, premiums written	616,794
United States | Non-life Run-off
Segment Reporting Information [Line Items]
Gross, premiums written	17,316
United States | Atrium
Segment Reporting Information [Line Items]
Gross, premiums written	79,433
United States | StarStone
Segment Reporting Information [Line Items]
Gross, premiums written	520,045
United States | Life and annuities
Segment Reporting Information [Line Items]
Gross, premiums written	0
United Kingdom
Segment Reporting Information [Line Items]
Gross, premiums written	108,166
United Kingdom | Non-life Run-off
Segment Reporting Information [Line Items]
Gross, premiums written	0
United Kingdom | Atrium
Segment Reporting Information [Line Items]
Gross, premiums written	9,200
United Kingdom | StarStone
Segment Reporting Information [Line Items]
Gross, premiums written	98,067
United Kingdom | Life and annuities
Segment Reporting Information [Line Items]
Gross, premiums written	899
Europe
Segment Reporting Information [Line Items]
Gross, premiums written	151,024
Europe | Non-life Run-off
Segment Reporting Information [Line Items]
Gross, premiums written	0
Europe | Atrium
Segment Reporting Information [Line Items]
Gross, premiums written	8,797
Europe | StarStone
Segment Reporting Information [Line Items]
Gross, premiums written	135,971
Europe | Life and annuities
Segment Reporting Information [Line Items]
Gross, premiums written	6,256
Asia
Segment Reporting Information [Line Items]
Gross, premiums written	49,966
Asia | Non-life Run-off
Segment Reporting Information [Line Items]
Gross, premiums written	0
Asia | Atrium
Segment Reporting Information [Line Items]
Gross, premiums written	6,766
Asia | StarStone
Segment Reporting Information [Line Items]
Gross, premiums written	43,200
Asia | Life and annuities
Segment Reporting Information [Line Items]
Gross, premiums written	0
Rest of World
Segment Reporting Information [Line Items]
Gross, premiums written	96,390
Rest of World | Non-life Run-off
Segment Reporting Information [Line Items]
Gross, premiums written	0
Rest of World | Atrium
Segment Reporting Information [Line Items]
Gross, premiums written	38,974
Rest of World | StarStone
Segment Reporting Information [Line Items]
Gross, premiums written	57,416
Rest of World | Life and annuities
Segment Reporting Information [Line Items]
Gross, premiums written	$ 0
Geographic concentration risk | Gross premiums written
Segment Reporting Information [Line Items]
Gross premiums written (percent)	100.00%
Geographic concentration risk | Gross premiums written | Non-life Run-off
Segment Reporting Information [Line Items]
Gross premiums written (percent)	100.00%
Geographic concentration risk | Gross premiums written | Atrium
Segment Reporting Information [Line Items]
Gross premiums written (percent)	100.00%
Geographic concentration risk | Gross premiums written | StarStone
Segment Reporting Information [Line Items]
Gross premiums written (percent)	100.00%
Geographic concentration risk | Gross premiums written | Life and annuities
Segment Reporting Information [Line Items]
Gross premiums written (percent)	100.00%
Geographic concentration risk | Gross premiums written | United States
Segment Reporting Information [Line Items]
Gross premiums written (percent)	60.30%
Geographic concentration risk | Gross premiums written | United States | Non-life Run-off
Segment Reporting Information [Line Items]
Gross premiums written (percent)	100.00%
Geographic concentration risk | Gross premiums written | United States | Atrium
Segment Reporting Information [Line Items]
Gross premiums written (percent)	55.50%
Geographic concentration risk | Gross premiums written | United States | StarStone
Segment Reporting Information [Line Items]
Gross premiums written (percent)	60.80%
Geographic concentration risk | Gross premiums written | United States | Life and annuities
Segment Reporting Information [Line Items]
Gross premiums written (percent)	0.00%
Geographic concentration risk | Gross premiums written | United Kingdom
Segment Reporting Information [Line Items]
Gross premiums written (percent)	10.60%
Geographic concentration risk | Gross premiums written | United Kingdom | Non-life Run-off
Segment Reporting Information [Line Items]
Gross premiums written (percent)	0.00%
Geographic concentration risk | Gross premiums written | United Kingdom | Atrium
Segment Reporting Information [Line Items]
Gross premiums written (percent)	6.40%
Geographic concentration risk | Gross premiums written | United Kingdom | StarStone
Segment Reporting Information [Line Items]
Gross premiums written (percent)	11.50%
Geographic concentration risk | Gross premiums written | United Kingdom | Life and annuities
Segment Reporting Information [Line Items]
Gross premiums written (percent)	12.60%
Geographic concentration risk | Gross premiums written | Europe
Segment Reporting Information [Line Items]
Gross premiums written (percent)	14.80%
Geographic concentration risk | Gross premiums written | Europe | Non-life Run-off
Segment Reporting Information [Line Items]
Gross premiums written (percent)	0.00%
Geographic concentration risk | Gross premiums written | Europe | Atrium
Segment Reporting Information [Line Items]
Gross premiums written (percent)	6.10%
Geographic concentration risk | Gross premiums written | Europe | StarStone
Segment Reporting Information [Line Items]
Gross premiums written (percent)	15.90%
Geographic concentration risk | Gross premiums written | Europe | Life and annuities
Segment Reporting Information [Line Items]
Gross premiums written (percent)	87.40%
Geographic concentration risk | Gross premiums written | Asia
Segment Reporting Information [Line Items]
Gross premiums written (percent)	4.90%
Geographic concentration risk | Gross premiums written | Asia | Non-life Run-off
Segment Reporting Information [Line Items]
Gross premiums written (percent)	0.00%
Geographic concentration risk | Gross premiums written | Asia | Atrium
Segment Reporting Information [Line Items]
Gross premiums written (percent)	4.70%
Geographic concentration risk | Gross premiums written | Asia | StarStone
Segment Reporting Information [Line Items]
Gross premiums written (percent)	5.10%
Geographic concentration risk | Gross premiums written | Asia | Life and annuities
Segment Reporting Information [Line Items]
Gross premiums written (percent)	0.00%
Geographic concentration risk | Gross premiums written | Rest of World
Segment Reporting Information [Line Items]
Gross premiums written (percent)	9.40%
Geographic concentration risk | Gross premiums written | Rest of World | Non-life Run-off
Segment Reporting Information [Line Items]
Gross premiums written (percent)	0.00%
Geographic concentration risk | Gross premiums written | Rest of World | Atrium
Segment Reporting Information [Line Items]
Gross premiums written (percent)	27.30%
Geographic concentration risk | Gross premiums written | Rest of World | StarStone
Segment Reporting Information [Line Items]
Gross premiums written (percent)	6.70%
Geographic concentration risk | Gross premiums written | Rest of World | Life and annuities
Segment Reporting Information [Line Items]
Gross premiums written (percent)	0.00%

Segment Information - Summar142

Segment Information - Summary of Company's Assets by Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 12,865,744	$ 11,772,534
Operating Segments | Non-life Run-off
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	8,297,103	7,602,594
Operating Segments | Atrium
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	563,754	559,377
Operating Segments | StarStone
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,968,316	2,780,462
Operating Segments | Life and annuities
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,644,013	1,695,994
Eliminations
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ (607,442)	$ (865,893)

Unaudited Condensed Quarterl143

Unaudited Condensed Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INCOME
Net premiums earned	$ 216,188	$ 205,730	$ 208,709	$ 192,887	$ 178,009	$ 209,971	$ 189,344	$ 176,420	$ 823,514	$ 753,744	$ 542,991
Fees and commission income	13,266	9,187	10,487	6,424	7,450	9,708	10,125	12,064	39,364	39,347	34,919
Net investment income	42,229	48,022	44,932	50,280	44,265	31,640	25,265	21,394	185,463	122,564	66,024
Net realized and unrealized gains (losses)	(61,570)	66,608	34,503	38,277	(56,705)	(15,835)	(8,296)	39,313	77,818	(41,523)	51,991
Other income	(1,277)	414	3,289	2,410	12,648	2,370	11,833	3,477	4,836	30,328	14,149
Total income	208,836	329,961	301,920	290,278	185,667	237,854	228,271	252,668	1,130,995	904,460	710,074
EXPENSES
Net incurred losses and loss adjustment expenses	1,321	(6,902)	96,462	83,218	(64,062)	32,359	65,900	70,136	174,099	104,333	9,146
Life and annuity policy benefits	(2,265)	1,682	(1,613)	158	(1,808)	401	407	454	(2,038)	(546)	84
Acquisition costs	47,619	50,074	43,847	45,029	53,666	44,445	33,781	31,824	186,569	163,716	117,542
General and administrative expenses	123,497	103,097	104,206	92,934	106,754	96,818	90,837	94,750	423,734	389,159	337,120
Interest expense	4,796	5,027	5,421	5,398	5,368	5,156	4,876	4,003	20,642	19,403	12,922
Net foreign exchange losses	(1,527)	2,276	(1,856)	1,772	7,004	(841)	2,297	(5,087)	665	3,373	5,962
Total expenses	173,441	155,254	246,467	228,509	106,922	178,338	198,098	196,080	803,671	679,438	482,776
EARNINGS BEFORE INCOME TAXES	35,395	174,707	55,453	61,769	78,745	59,516	30,173	56,588	327,324	225,022	227,298
INCOME TAXES	(11,228)	(8,227)	(8,050)	(7,369)	15,794	(12,684)	(8,087)	(7,673)	(34,874)	(12,650)	(5,601)
NET EARNINGS FROM CONTINUING OPERATIONS	24,167	166,480	47,403	54,400	94,539	46,832	22,086	48,915	292,450	212,372	221,697
NET EARNINGS (LOSS) FROM DISCONTINUING OPERATIONS, NET OF INCOME TAX EXPENSE	5,483	3,897	2,378	205	(1,898)	(831)	(3,879)	4,577	11,963	(2,031)	5,539
NET EARNINGS	29,650	170,377	49,781	54,605	92,641	46,001	18,207	53,492	304,413	210,341	227,236
Less: Net loss (earnings) attributable to noncontrolling interest	(7,005)	(14,329)	(9,187)	(9,085)	19,216	3,041	(3,662)	(8,645)	(39,606)	9,950	(13,487)
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED	$ 22,645	$ 156,048	$ 40,594	$ 45,520	$ 111,857	$ 49,042	$ 14,545	$ 44,847	$ 264,807	$ 220,291	$ 213,749
Basic:
Net earnings from continuing operations (dollars per share)	$ 0.91	$ 7.86	$ 1.99	$ 2.34	$ 5.91	$ 2.57	$ 0.99	$ 2.04	$ 13.10	$ 11.55	$ 11.31
Net earnings (loss) from discontinuing operations (dollars per share)	0.26	0.23	0.11	0.02	(0.11)	(0.02)	(0.23)	0.29	0.62	(0.11)	0.30
Net earnings per ordinary share (dollars per share)	1.17	8.09	2.10	2.36	5.80	2.55	0.76	2.33	13.72	11.44	11.61
Diluted:
Net earnings from continuing operations (dollars per share)	0.90	7.79	1.98	2.33	5.86	2.55	0.98	2.03	13	11.46	11.15
Net earnings (loss) from discontinuing operations (dollars per share)	0.26	0.23	0.11	0.02	(0.11)	(0.02)	(0.23)	0.29	0.62	(0.11)	0.29
Net earnings per ordinary share (dollars per share)	$ 1.16	$ 8.02	$ 2.09	$ 2.35	$ 5.75	$ 2.53	$ 0.75	$ 2.32	$ 13.62	$ 11.35	$ 11.44

Schedule I - Summary of Inve144

Schedule I - Summary of Investments Other Than Investments in Related Parties (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	$ 5,705,240
Fair Value	5,672,598
Amount at which shown in the balance sheet	5,674,775
Equities, trading, at fair value	95,047	$ 111,495
Fair value of other investments in funds or companies owned by or affiliated with related parties	937,047	980,289
Affiliated entity
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Fair value of other investments in funds or companies owned by or affiliated with related parties	347,000
Affiliated entity | Trident
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Equities, trading, at fair value	20,900	21,000
Fair value of other investments in funds or companies owned by or affiliated with related parties	232,100	$ 237,900
Equities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	67,516
Fair Value	74,149
Amount at which shown in the balance sheet	74,149
Other investments, at fair value
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	590,048
Fair Value	590,048
Amount at which shown in the balance sheet	590,048
Other investments, at cost
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	131,651
Fair Value	129,474
Amount at which shown in the balance sheet	131,651
Trading securities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	4,646,161
Fair Value	4,611,160
Amount at which shown in the balance sheet	4,611,160
Trading securities | U.S. government and agency
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	844,746
Fair Value	840,274
Amount at which shown in the balance sheet	840,274
Trading securities | Non-U.S. government
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	275,900
Fair Value	267,363
Amount at which shown in the balance sheet	267,363
Trading securities | Corporate
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	2,402,062
Fair Value	2,387,322
Amount at which shown in the balance sheet	2,387,322
Trading securities | Municipal
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	47,615
Fair Value	47,181
Amount at which shown in the balance sheet	47,181
Trading securities | Residential mortgage-backed
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	378,516
Fair Value	373,528
Amount at which shown in the balance sheet	373,528
Trading securities | Commercial mortgage-backed
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	220,727
Fair Value	217,212
Amount at which shown in the balance sheet	217,212
Trading securities | Asset-backed
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	476,595
Fair Value	478,280
Amount at which shown in the balance sheet	478,280
Available-for-sale securities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	269,864
Fair Value	267,767
Amount at which shown in the balance sheet	267,767
Available-for-sale securities | U.S. government and agency
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	12,784
Fair Value	12,710
Amount at which shown in the balance sheet	12,710
Available-for-sale securities | Non-U.S. government
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	86,897
Fair Value	85,423
Amount at which shown in the balance sheet	85,423
Available-for-sale securities | Corporate
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	159,243
Fair Value	158,655
Amount at which shown in the balance sheet	158,655
Available-for-sale securities | Municipal
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	6,585
Fair Value	6,576
Amount at which shown in the balance sheet	6,576
Available-for-sale securities | Residential mortgage-backed
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	488
Fair Value	527
Amount at which shown in the balance sheet	527
Available-for-sale securities | Asset-backed
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	3,867
Fair Value	3,876
Amount at which shown in the balance sheet	$ 3,876

Schedule II - Condensed Balance

Schedule II - Condensed Balance Sheets (Detail) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 08, 2013
ASSETS
Cash and cash equivalents	$ 954,871	$ 795,245	$ 897,674
Other assets	842,356	509,110
TOTAL ASSETS	12,865,744	11,772,534
LIABILITIES
Loans payable	673,603	599,750
Other liabilities	705,318	350,752
TOTAL LIABILITIES	9,600,390	8,834,088
SHAREHOLDERS’ EQUITY
Treasury shares at cost (Preferred shares 2016: 388,571; Series A non-voting convertible ordinary shares 2015: 2,972,892)	(421,559)	(421,559)
Additional paid-in capital	1,380,109	1,373,044
Accumulated other comprehensive loss	(23,549)	(35,162)
Retained earnings	1,847,550	1,578,312
Total Enstar Group Limited Shareholders’ Equity	2,802,312	2,516,872
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTEREST AND SHAREHOLDERS’ EQUITY	$ 12,865,744	$ 11,772,534
Parenthetical Disclosures [Abstract]
Common shares, par value (dollars per share)	$ 1	$ 1
Preferred shares, par value (dollars per share)	$ 1	$ 1
Share capital, authorized (shares)	156,000,000	156,000,000
Voting ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	$ 16,175	$ 16,133
Parenthetical Disclosures [Abstract]
Common shares, par value (dollars per share)	$ 1	$ 1			$ 1
Ordinary shares, shares issued (shares)	16,175,250	16,133,334
Ordinary shares, outstanding (shares)	16,175,250	16,133,334
Series A non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	$ 0	$ 2,973
Parenthetical Disclosures [Abstract]
Ordinary shares, shares issued (shares)	0	2,972,892
Treasury shares (shares)	0	2,972,892
Series C non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	$ 2,792	$ 2,726
Parenthetical Disclosures [Abstract]
Ordinary shares, shares issued (shares)	2,792,157	2,725,637
Ordinary shares, outstanding (shares)	2,792,157	2,725,637
Series E non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	$ 405	$ 405
Parenthetical Disclosures [Abstract]
Ordinary shares, shares issued (shares)	404,771	404,771	714,015
Ordinary shares, outstanding (shares)	404,771	404,771	714,015,000
Series C non-voting preferred shares
SHAREHOLDERS’ EQUITY
Series C Preferred Shares (issued and outstanding 2016: 388,571; 2015: nil)	$ 389	$ 0
Parenthetical Disclosures [Abstract]
Preferred shares, issued (shares)	388,571	0
Preferred shares, outstanding (shares)	388,571	0
Treasury shares (shares)	388,571	0
Enstar Group Limited
ASSETS
Cash and cash equivalents	$ 4,884	$ 4,552	$ 21,671	$ 27,989
Balances due from subsidiaries	35,563	489,873
Investments in subsidiaries	3,400,401	2,674,084
Other assets	8,533	7,812
TOTAL ASSETS	3,449,381	3,176,321
LIABILITIES
Loans payable	488,103	485,750
Balances due to subsidiaries	153,843	160,854
Other liabilities	5,123	12,845
TOTAL LIABILITIES	647,069	659,449
SHAREHOLDERS’ EQUITY
Treasury shares at cost (Preferred shares 2016: 388,571; Series A non-voting convertible ordinary shares 2015: 2,972,892)	(421,559)	(421,559)
Additional paid-in capital	1,380,109	1,373,044
Accumulated other comprehensive loss	(23,549)	(35,162)
Retained earnings	1,847,550	1,578,312
Total Enstar Group Limited Shareholders’ Equity	2,802,312	2,516,872
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTEREST AND SHAREHOLDERS’ EQUITY	$ 3,449,381	$ 3,176,321
Parenthetical Disclosures [Abstract]
Common shares, par value (dollars per share)	$ 1	$ 1
Share capital, authorized (shares)	156,000,000	156,000,000
Enstar Group Limited | Voting ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	$ 16,175	$ 16,133
Parenthetical Disclosures [Abstract]
Ordinary shares, shares issued (shares)	16,175,250	16,133,334
Ordinary shares, outstanding (shares)	16,175,250	16,133,334
Enstar Group Limited | Series A non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	$ 0	$ 2,973
Parenthetical Disclosures [Abstract]
Ordinary shares, shares issued (shares)	0	2,972,892
Treasury shares (shares)	0	2,972,892
Enstar Group Limited | Series C non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	$ 2,792	$ 2,726
Parenthetical Disclosures [Abstract]
Ordinary shares, shares issued (shares)	2,792,157	2,725,637
Ordinary shares, outstanding (shares)	2,792,157	2,725,637
Enstar Group Limited | Series E non-voting convertible ordinary shares
SHAREHOLDERS’ EQUITY
Ordinary shares	$ 405	$ 405
Parenthetical Disclosures [Abstract]
Ordinary shares, shares issued (shares)	404,771	404,771
Ordinary shares, outstanding (shares)	404,771	404,771
Enstar Group Limited | Series C non-voting preferred shares
SHAREHOLDERS’ EQUITY
Series C Preferred Shares (issued and outstanding 2016: 388,571; 2015: nil)	$ 389	$ 0
Parenthetical Disclosures [Abstract]
Preferred shares, issued (shares)	388,571	0
Preferred shares, outstanding (shares)	388,571	0
Treasury shares (shares)	388,571	0

Schedule II - Condensed Stateme

Schedule II - Condensed Statements of Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
INCOME
Net investment income	$ 42,229	$ 48,022	$ 44,932	$ 50,280	$ 44,265	$ 31,640	$ 25,265	$ 21,394	$ 185,463	$ 122,564	$ 66,024
Total income	208,836	329,961	301,920	290,278	185,667	237,854	228,271	252,668	1,130,995	904,460	710,074
EXPENSES
General and administrative expenses	123,497	103,097	104,206	92,934	106,754	96,818	90,837	94,750	423,734	389,159	337,120
Interest expense	4,796	5,027	5,421	5,398	5,368	5,156	4,876	4,003	20,642	19,403	12,922
Net foreign exchange losses	(1,527)	2,276	(1,856)	1,772	7,004	(841)	2,297	(5,087)	665	3,373	5,962
Total expenses	173,441	155,254	246,467	228,509	106,922	178,338	198,098	196,080	803,671	679,438	482,776
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED	$ 22,645	$ 156,048	$ 40,594	$ 45,520	$ 111,857	$ 49,042	$ 14,545	$ 44,847	264,807	220,291	213,749
Enstar Group Limited
INCOME
Net investment income									44	14,965	11,865
Dividend income from subsidiaries									361,675	1,000	21,952
Total income									361,719	15,965	33,817
EXPENSES
General and administrative expenses									59,755	50,349	43,241
Interest expense									10,109	8,693	8,201
Net foreign exchange losses									(318)	213	379
Total expenses									69,546	59,255	51,821
EARNINGS (LOSS) BEFORE EQUITY IN UNDISTRIBUTED EARNINGS OF SUBSIDIARIES									292,173	(43,290)	(18,004)
EQUITY IN UNDISTRIBUTED EARNINGS OF SUBSIDIARIES - CONTINUING OPERATIONS									(39,329)	265,612	226,214
EQUITY IN UNDISTRIBUTED EARNINGS OF SUBSIDIARIES - DISCONTINUING OPERATIONS									11,963	(2,031)	5,539
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									$ 264,807	$ 220,291	$ 213,749

Schedule II - Comprehensive Inc

Schedule II - Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Statement of Income Captions [Line Items]
NET EARNINGS	$ 22,645	$ 156,048	$ 40,594	$ 45,520	$ 111,857	$ 49,042	$ 14,545	$ 44,847	$ 264,807	$ 220,291	$ 213,749
COMPREHENSIVE INCOME ATTRIBUTABLE TO ENSTAR GROUP LIMITED									276,420	197,815	187,085
Enstar Group Limited
Condensed Statement of Income Captions [Line Items]
NET EARNINGS									264,807	220,291	213,749
OTHER COMPREHENSIVE INCOME (LOSS) RELATING TO SUBSIDIARIES, NET OF TAX									11,613	(22,476)	(26,664)
COMPREHENSIVE INCOME ATTRIBUTABLE TO ENSTAR GROUP LIMITED									$ 276,420	$ 197,815	$ 187,085

Schedule II - Condensed Stat148

Schedule II - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES:
Net cash flows provided by (used in) operating activities	$ (202,689)	$ (265,152)	$ 544,005
INVESTING ACTIVITIES:
Net cash flows provided by (used in) investing activities	156,709	19,885	(187,422)
FINANCING ACTIVITIES:
Repayment of loans	(493,250)	(377,500)	(199,245)
Receipt of loans	571,048	657,700	70,000
Net cash flows provided by financing activities	83,441	129,347	131,586
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF YEAR	795,245	897,674
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, END OF YEAR	954,871	795,245	897,674
Enstar Group Limited
OPERATING ACTIVITIES:
Net cash flows provided by (used in) operating activities	39,185	(81,384)	(88,970)
INVESTING ACTIVITIES:
Dividends and return of capital from subsidiaries	250,117	1,000	21,952
Contributions to subsidiaries	(295,268)	(218,935)	(50)
Net cash flows provided by (used in) investing activities	(45,151)	(217,935)	21,902
FINANCING ACTIVITIES:
Repayment of loans	(426,750)	(223,500)	(9,250)
Receipt of loans	433,048	505,700	70,000
Net cash flows provided by financing activities	6,298	282,200	60,750
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	332	(17,119)	(6,318)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF YEAR	4,552	21,671	27,989
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, END OF YEAR	$ 4,884	$ 4,552	$ 21,671

Schedule II - Narrative (Detail

Schedule II - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Interest paid									$ 19,451	$ 19,395	$ 16,130
Dividends and return of capital from subsidiaries, non-cash									111,600
Contributions to subsidiaries, non-cash									452,100
Retained earnings	$ 1,847,550				$ 1,578,312				1,847,550	1,578,312
Net earnings attributable to Enstar Group Limited	22,645	$ 156,048	$ 40,594	$ 45,520	111,857	$ 49,042	$ 14,545	$ 44,847	264,807	220,291	213,749
Limited parental guarantee
Condensed Financial Statements, Captions [Line Items]
Total parental guarantees	625,700				334,200				625,700	334,200
Enstar Group Limited
Condensed Financial Statements, Captions [Line Items]
Interest paid									15,000	13,000	6,600
Retained earnings	1,847,550				1,578,312				1,847,550	1,578,312
Increase in retained earnings									269,200
Net earnings attributable to Enstar Group Limited									264,807	220,291	$ 213,749
Enstar Group Limited | Limited parental guarantee
Condensed Financial Statements, Captions [Line Items]
Total parental guarantees	$ 625,700				$ 334,200				$ 625,700	$ 334,200

Schedule III - Supplementary150

Schedule III - Supplementary Insurance Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs	$ 58,114	$ 89,123	$ 61,706
Reserves for Losses and Loss Adjustment Expenses	5,987,867	5,720,149	4,509,421
Unearned Premiums	548,343	542,771	467,933
Policy Benefits for Life and Annuity Contracts	112,095	126,321	8,940
Net Premiums Earned	823,514	753,744	542,991
Net Investment Income	185,463	122,564	66,024
Losses and Loss Expenses and Policy Benefits	172,060	103,787	9,230
Amortization of Deferred Acquisition Costs	186,569	163,716	132,573
Other Operating Expenses	445,042	411,935	356,004
Net Premiums Written	803,936	787,154	547,956
Operating Segments | Non-life Run-off
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs	1,081	1,788	0
Reserves for Losses and Loss Adjustment Expenses	4,716,363	4,585,454	3,435,010
Unearned Premiums	15,107	27,792	197
Policy Benefits for Life and Annuity Contracts	0	0	0
Net Premiums Earned	16,755	44,369	31,168
Net Investment Income	143,783	84,185	57,899
Losses and Loss Expenses and Policy Benefits	(285,881)	(270,830)	(264,711)
Amortization of Deferred Acquisition Costs	4,198	8,860	8,393
Other Operating Expenses	296,384	257,926	213,571
Net Premiums Written	9,202	22,594	10,272
Operating Segments | Atrium
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs	16,964	16,326	16,520
Reserves for Losses and Loss Adjustment Expenses	212,122	201,017	212,611
Unearned Premiums	61,862	59,808	61,030
Policy Benefits for Life and Annuity Contracts	0	0	0
Net Premiums Earned	124,416	134,675	135,945
Net Investment Income	2,940	2,225	1,748
Losses and Loss Expenses and Policy Benefits	58,386	47,479	55,428
Amortization of Deferred Acquisition Costs	44,670	45,509	43,417
Other Operating Expenses	28,641	36,087	38,791
Net Premiums Written	140,437	134,580	136,275
Operating Segments | StarStone
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs	40,069	71,009	45,186
Reserves for Losses and Loss Adjustment Expenses	1,059,382	933,678	861,800
Unearned Premiums	471,374	455,171	406,706
Policy Benefits for Life and Annuity Contracts	0	0	0
Net Premiums Earned	676,608	573,146	373,633
Net Investment Income	22,221	15,937	5,321
Losses and Loss Expenses and Policy Benefits	401,593	327,684	218,429
Amortization of Deferred Acquisition Costs	138,822	109,347	65,734
Other Operating Expenses	124,572	125,658	114,289
Net Premiums Written	648,036	628,427	399,174
Operating Segments | Life and annuities
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs	0	0	0
Reserves for Losses and Loss Adjustment Expenses	0	0	0
Unearned Premiums	0	0	0
Policy Benefits for Life and Annuity Contracts	112,095	126,321	8,940
Net Premiums Earned	5,735	1,554	2,245
Net Investment Income	20,043	21,137	1,056
Losses and Loss Expenses and Policy Benefits	(2,038)	(546)	84
Amortization of Deferred Acquisition Costs	612	0	15,029
Other Operating Expenses	7,993	3,555	(16)
Net Premiums Written	6,261	1,553	2,235
Eliminations
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs	0	0	0
Reserves for Losses and Loss Adjustment Expenses	0	0	0
Unearned Premiums	0	0	0
Policy Benefits for Life and Annuity Contracts	0	0	0
Net Premiums Earned	0	0	0
Net Investment Income	(3,524)	(920)	0
Losses and Loss Expenses and Policy Benefits	0	0	0
Amortization of Deferred Acquisition Costs	(1,733)	0	0
Other Operating Expenses	(12,548)	(11,291)	(10,631)
Net Premiums Written	$ 0	$ 0	$ 0

Schedule IV - Reinsurance (Deta

Schedule IV - Reinsurance (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Life insurance in force, gross	$ 2,317,567				$ 2,978,466				$ 2,317,567	$ 2,978,466	$ 901,639
Life insurance in force, ceded	(585,575)				(777,759)				(585,575)	(777,759)	(808,142)
Life insurance in force, assumed	0				0				0	0	0
Life insurance in force, net	$ 1,731,992				$ 2,200,707				$ 1,731,992	$ 2,200,707	$ 93,497
Life insurance in force, percentage of amount assumed to net	0.00%				0.00%				0.00%	0.00%	0.00%
Premiums earned, gross									$ 811,362	$ 857,740	$ 707,170
Premiums earned, ceded									(180,320)	(284,819)	(219,027)
Premiums earned, assumed									192,472	180,823	54,848
Net, premiums earned	$ 216,188	$ 205,730	$ 208,709	$ 192,887	$ 178,009	$ 209,971	$ 189,344	$ 176,420	823,514	753,744	542,991
Property and casualty
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Premiums earned, gross									804,141	854,856	703,281
Premiums earned, ceded									(178,834)	(283,489)	(217,383)
Premiums earned, assumed									192,472	180,823	54,848
Net, premiums earned									$ 817,779	$ 752,190	$ 540,746
Premiums earned, percentage of amount assumed to net									23.50%	24.00%	10.10%
Life and annuities
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Premiums earned, gross									$ 7,221	$ 2,884	$ 3,889
Premiums earned, ceded									(1,486)	(1,330)	(1,644)
Premiums earned, assumed									0	0	0
Net, premiums earned									$ 5,735	$ 1,554	$ 2,245
Premiums earned, percentage of amount assumed to net									0.00%	0.00%	0.00%

Schedule V - Valuation and Q152

Schedule V - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance balances recoverable, provisions for bad debt
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 174,516	$ 210,327	$ 289,909	$ 338,614
Charged to costs and expenses	(13,822)	(25,271)	(7,700)
Charged to other accounts	(19,255)	(45,234)	(28,665)
Deductions	(2,734)	(9,077)	(12,340)
Balance at End of Year	174,516	210,327	289,909
Valuation allowance for deferred tax assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	290,861	291,280	333,617	$ 255,126
Charged to costs and expenses	13,389	(17,379)	(33,213)
Charged to other accounts	0	0	0
Deductions	(13,808)	(24,958)	111,704
Balance at End of Year	$ 290,861	$ 291,280	$ 333,617

Schedule VI - Supplementary 153

Schedule VI - Supplementary Information Concerning Property/Casualty Insurance Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Deferred Acquisition Costs	$ 58,114	$ 89,123	$ 61,706
Reserves for Unpaid Losses and Loss Adjustment Expenses	5,987,867	5,720,149	4,509,421
Unearned Premiums	548,343	542,771	467,933
Net Premiums Earned	817,779	752,190	540,746
Net Investment Income	168,944	102,347	64,968
Net Losses and Loss Expenses Incurred - Current Year	493,016	476,364	327,817
Net Loses and Loss Expenses Incurred - Prior Year	(318,917)	(372,031)	(318,671)
Net Paid Losses and Loss Expenses	(833,057)	(781,889)	(587,511)
Amortization of Deferred Acquisition Costs	187,690	163,716	117,544
Net Premiums Written	$ 797,675	$ 785,601	$ 545,721