Endurance Specialty (ENH) 10-K 26 Feb 16 2015 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 22, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Entity Registrant Name	Endurance Specialty Holdings Ltd.
Entity Central Index Key	1,179,755
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		66,921,641
Entity Public Float			$ 2,399,392,711

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Fixed maturity investments, trading at fair value (amortized cost: $1,611,079 and nil at December 31, 2015 and 2014, respectively)	$ 1,587,160	$ 0
Fixed maturity investments, available for sale at fair value (amortized cost: $4,361,997 and $5,032,506 at December 31, 2015 and 2014, respectively)	4,359,019	5,092,581
Short-term investments, trading at fair value (amortized cost: $394,096 and nil at December 31, 2015 and 2014, respectively)	394,111	0
Short-term investments, available for sale at fair value (amortized cost: $25,657 and $9,015 at December 31, 2015 and 2014, respectively)	25,685	9,014
Equity securities, trading at fair value (amortized cost: $15,290 and nil at December 31, 2015 and 2014, respectively)	15,229	0
Equity securities, available for sale at fair value (cost: $542,429 and $303,922 at December 31, 2015 and 2014, respectively)	513,585	331,368
Other investments	872,617	541,454
Total investments	7,767,406	5,974,417
Cash and cash equivalents	1,177,750	745,472
Premiums receivable, net	1,376,328	883,450
Insurance and reinsurance balances receivable	102,403	122,214
Deferred acquisition costs	255,501	207,368
Prepaid reinsurance premiums	498,574	354,940
Reinsurance recoverable on unpaid losses	907,944	670,795
Reinsurance recoverable on paid losses	288,026	218,291
Accrued investment income	30,213	27,183
Goodwill and intangible assets	553,960	153,405
Deferred tax asset	64,164	48,995
Net receivable on sales of investments	31,873	38,877
Other assets	187,383	195,277
Total assets	13,241,525	9,640,684
LIABILITIES
Reserve for losses and loss expenses	4,510,415	3,846,859
Reserve for unearned premiums	1,789,148	1,254,519
Deposit liabilities	13,674	15,136
Reinsurance balances payable	661,213	375,711
Debt	717,650	523,617
Net payable on purchases of investments	63,442	151,682
Deferred tax liability	17,315	0
Other liabilities	344,596	287,978
Total liabilities	$ 8,117,453	$ 6,455,502
Commitments and contingent liabilities
SHAREHOLDERS' EQUITY
Preferred shares, total liquidation preference $460,000 (2014 - $430,000)	$ 9,209	$ 17,200
Common shares, ordinary - 66,797,991 issued and outstanding (2014 - 44,765,153)	66,798	44,765
Additional paid-in capital	2,145,836	598,226
Accumulated other comprehensive (loss) income	(46,634)	76,706
Retained earnings	2,681,053	2,448,285
Total shareholders' equity available to Endurance Holdings	4,856,262	3,185,182
Non-controlling interests	267,810	0
Total shareholders' equity	5,124,072	3,185,182
Total liabilities and shareholders' equity	$ 13,241,525	$ 9,640,684

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Investments [Abstract]
Fixed maturity investments, trading, amortized cost	$ 1,611,079	$ 0
Fixed maturity investments, available for sale, amortized cost	4,361,997	5,032,506
Short-term investments, trading, amortized cost	394,096	0
Short-term investments, available for sale, amortized cost	25,657	9,015
Equity securities, trading, cost	15,290	0
Equity securities, available for sale, cost	542,429	303,922
Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred shares, total liquidation preference	$ 460,000	$ 430,000
Common shares, ordinary, number of shares issued	66,797,991	44,765,153
Common shares, ordinary, number of shares outstanding	66,797,991	44,765,153

Consolidated Statements Of Inco

Consolidated Statements Of Income And Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Gross premiums written	$ 3,320,861	$ 2,894,076	$ 2,665,244
Ceded premiums written	(1,370,391)	(959,870)	(616,311)
Net premiums written	1,950,470	1,934,206	2,048,933
Change in unearned premiums	27,983	(70,228)	(32,449)
Net premiums earned	1,978,453	1,863,978	2,016,484
Net investment income	113,826	131,543	166,216
Net realized and unrealized gains	12,660	14,283	15,164
Net impairment losses recognized in earnings	(3,715)	(625)	(1,616)
Other underwriting loss	(3,694)	(5,786)	(2,046)
Total revenues	2,097,530	2,003,393	2,194,202
Expenses
Net losses and loss expenses	917,108	970,162	1,219,684
Acquisition expenses	347,885	319,513	304,430
General and administrative expenses	259,791	247,387	236,873
Corporate expenses	114,429	66,200	58,033
Amortization of intangibles	30,620	6,484	7,012
Net foreign exchange losses	26,964	3,839	14,214
Interest expense	41,260	40,968	36,188
Total expenses	1,738,057	1,654,553	1,876,434
Income before income taxes	359,473	348,840	317,768
Income tax expense	(4,362)	(390)	(5,853)
Net income	355,111	348,450	311,915
Net income attributable to non-controlling interests	(11,016)	0	0
Net income available to Endurance Holdings	344,095	348,450	311,915
Preferred dividends	(32,750)	(32,750)	(32,750)
Net income available to Endurance Holdings' common and participating common shareholders	311,345	315,700	279,165
Comprehensive income
Net income	355,111	348,450	311,915
Other comprehensive (loss) income
Net unrealized holding (losses) gains on investments arising during the period (net of other-than-temporary impairment losses recognized in other comprehensive (loss) income, reclassification adjustment and applicable deferred income tax benefit (expense) in 2015 - $5,890; 2014 - ($4,121); 2013 - $10,613)	(98,738)	40,150	(95,781)
Foreign currency translation adjustments	(24,690)	(26,264)	5,960
Reclassification adjustment for net losses on derivatives designated as cash flow hedge included in net income	88	89	89
Other comprehensive (loss) income	(123,340)	13,975	(89,732)
Comprehensive income	231,771	362,425	222,183
Comprehensive income attributable to non-controlling interests	(11,016)	0	0
Comprehensive income attributable to Endurance Holdings common and participating common shareholders	$ 220,755	$ 362,425	$ 222,183
Per share data
Basic earnings per common share	$ 5.74	$ 7.07	$ 6.37
Diluted earnings per common share	$ 5.73	$ 7.06	$ 6.37

Consolidated Statements Of Inc5

Consolidated Statements Of Income And Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Deferred income taxes on net unrealized holding (losses) gains on investments	$ 5,890	$ (4,121)	$ 10,613

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred equity investments	Common Stock [Member]	Additional Paid-in Capital [Member]	Cumulative Foreign Currency Translation Adjustments [Member]	Unrealized Holding (Losses) Gains On Investments, Net Of Deferred Taxes [Member]	Accumulated Derivative Loss On Cash Flow Hedging Instruments [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Retained Earnings [Member]
Balance, beginning of year at Dec. 31, 2012		$ 17,200	$ 43,116	$ 527,915	$ 12,676	$ 141,731	$ (1,944)		$ 1,969,903
Issuance of Series C, non-cumulative preferred shares		0		0
Redemption of Series A, non-cumulative preferred shares		0		0
Issuance of common shares, net of forfeitures			1,571	30,480
Public offering and registration costs				0
Repurchase of common shares			(318)	(14,266)
Settlement of equity awards				(3,001)
Stock-based compensation expense				27,988
Foreign currency translation adjustments	$ 5,960				5,960
Net unrealized holding (losses) gains arising during the year, net of other-than-temporary impairment losses and reclassification adjustment	(95,781)					(95,781)
Net change from current period hedging transactions, net of reclassification adjustment							89
Net income	311,915								311,915
Net income attributable to non-controlling interests	0								0
Dividends on preferred shares	(32,750)								(32,750)
Dividends on common shares									(55,935)
Balance, end of year at Dec. 31, 2013	2,886,549	17,200	44,369	569,116	18,636	45,950	(1,855)	$ 62,731	2,193,133
Non-controlling interests	0
Issuance of Series C, non-cumulative preferred shares		0		0
Redemption of Series A, non-cumulative preferred shares		0		0
Issuance of common shares, net of forfeitures			396	2,143
Public offering and registration costs				0
Repurchase of common shares			0	0
Settlement of equity awards				(4,039)
Stock-based compensation expense				31,006
Foreign currency translation adjustments	(26,264)				(26,264)
Net unrealized holding (losses) gains arising during the year, net of other-than-temporary impairment losses and reclassification adjustment	40,150					40,150
Net change from current period hedging transactions, net of reclassification adjustment							89
Net income	348,450								348,450
Net income attributable to non-controlling interests	0								0
Dividends on preferred shares	(32,750)								(32,750)
Dividends on common shares									(60,548)
Balance, end of year at Dec. 31, 2014	3,185,182	17,200	44,765	598,226	(7,628)	86,100	(1,766)	76,706	2,448,285
Non-controlling interests	0
Total shareholders' equity	3,185,182
Issuance of Series C, non-cumulative preferred shares		9		222,954
Redemption of Series A, non-cumulative preferred shares		(8,000)		(192,000)
Issuance of common shares, net of forfeitures			22,033	1,476,615
Public offering and registration costs				(936)
Repurchase of common shares			0	0
Settlement of equity awards				(14,535)
Stock-based compensation expense				55,512
Foreign currency translation adjustments	(24,690)				(24,690)
Net unrealized holding (losses) gains arising during the year, net of other-than-temporary impairment losses and reclassification adjustment	(98,738)					(98,738)
Net change from current period hedging transactions, net of reclassification adjustment							88
Net income	355,111								355,111
Net income attributable to non-controlling interests	(11,016)								11,016
Dividends on preferred shares	(32,750)								(32,750)
Dividends on common shares									(78,577)
Balance, end of year at Dec. 31, 2015	4,856,262	9,209	66,798	2,145,836	(32,318)	(12,638)	(1,678)	(46,634)	2,681,053
Non-controlling interests	258,529
Net income attributable to non-controlling interests	(11,016)
Balance, end of year at Dec. 31, 2015	4,856,262	$ 9,209	$ 66,798	$ 2,145,836	$ (32,318)	$ (12,638)	$ (1,678)	$ (46,634)	$ 2,681,053
Non-controlling interests	267,810
Total shareholders' equity	$ 5,124,072

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows provided by operating activities:
Net income	$ 355,111	$ 348,450	$ 311,915
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of net premium on investments	45,317	45,757	53,336
Amortization of other intangibles and depreciation	51,457	27,234	21,250
Net realized and unrealized gains	(12,660)	(14,283)	(15,164)
Net impairment losses recognized in earnings	3,715	625	1,616
Deferred taxes	(2,727)	(1,414)	2,412
Stock-based compensation expense	55,512	31,006	27,988
Equity in earnings of other investments	13,553	(19,608)	(64,321)
Premiums receivable, net	(153,735)	(214,252)	(67,246)
Insurance and reinsurance balances receivable	33,729	5,508	(22,059)
Deferred acquisition costs	(48,133)	(21,341)	(17,775)
Prepaid reinsurance premiums	(74,944)	(167,731)	(20,507)
Reinsurance recoverable on unpaid losses	(197,097)	(77,040)	98,028
Reinsurance recoverable on paid losses	(61,748)	(54,071)	(81,061)
Accrued investment income	5,840	(3,079)	3,062
Other assets	(25,683)	(17,132)	(10,372)
Reserve for losses and loss expenses	(57,375)	(155,400)	(238,617)
Reserve for unearned premiums	36,036	235,668	53,607
Deposit liabilities	(1,462)	(4,322)	(2,762)
Reinsurance balances payable	204,557	194,650	70,218
Other liabilities	76,194	127,036	54,376
Net cash flows provided by operating activities	245,457	266,261	157,924
Cash flows provided by (used in) investing activities
Proceeds from sales and maturities of trading investments	626,914	0	0
Proceeds from sales and maturities of available for sale investments	5,725,794	4,145,940	4,023,339
Proceeds from the redemption of other investments	188,060	154,655	31,961
Purchases of trading investments	(1,080,478)	0	0
Purchases of available for sale investments	(5,421,949)	(4,449,225)	(4,259,800)
Purchases of other investments	(221,457)	(59,023)	(67,572)
Net settlements of other assets	21,273	11,665	(50,355)
Purchases of fixed assets	(26,988)	(40,932)	(24,960)
Net cash received for subsidiary acquisition	675,624	39
Net cash paid for subsidiary acquisition			(390)
Net cash flows provided by (used in) investing activities	486,793	(236,881)	(347,777)
Cash flows used in financing activities
Issuance of common shares	24,823	2,305	31,884
Issuance of Series C, non-cumulative preferred shares	222,963	0	0
Repurchase of common shares	0	0	(14,584)
Redemption of Series A, non-cumulative preferred shares	(200,000)	0	0
Settlement of equity awards	(14,535)	(4,039)	(3,001)
Net contributions to non-controlling interests	(1,739)	0	0
Offering and registration costs paid	(617)	0	0
Bridge facility costs paid	0	(4,750)	0
Proceeds from issuance of debt	5,008	706	703
Repayments of debt	(199,454)	(686)	(768)
Dividends on preferred shares	(32,750)	(32,750)	(32,750)
Dividends on Endurance Holdings' common shares	(78,473)	(60,524)	(55,906)
Net cash flows used in financing activities	(274,774)	(99,738)	(74,422)
Effect of exchange rate changes on cash and cash equivalents	(25,198)	(30,021)	(13,893)
Net increase (decrease) in cash and cash equivalents	432,278	(100,379)	(278,168)
Cash and cash equivalents, beginning of year	745,472	845,851	1,124,019
Cash and cash equivalents, end of year	$ 1,177,750	$ 745,472	$ 845,851

Organization

Organization	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Endurance Specialty Holdings Ltd. ("Endurance Holdings", together with its subsidiaries, the "Company") was organized as a Bermuda holding company on June 27, 2002. On July 31, 2015, the Company acquired all of the outstanding common shares of Montpelier Re Holding Ltd. ("Montpelier"), a Bermuda based provider of global property and casualty reinsurance and insurance products. As part of the acquisition, the Company acquired Montpelier's Lloyd's of London ("Lloyd's") operations, including Syndicate 5151 ("Syndicate 5151") and its managing agent, Endurance at Lloyd's Limited ("Endurance at Lloyd's"). Also as part of the acquisition, the Company acquired Montpelier's collateralized reinsurance and third party asset management operations, operating under the name "Blue Capital", which includes Blue Capital Management Ltd. ("BCML"), a wholly-owned subsidiary that provides investment and insurance management services to the Blue Capital vehicles primarily through business written in Blue Water Re Ltd. ("Blue Water Re") and Blue Water Re II Ltd. ("Blue Water Re II"), wholly-owned special purpose insurers. See Note 4, Investments, for additional information with respect to the Blue Capital entities. The Company's Consolidated Statements of Income and Comprehensive Income for the year ended December 31, 2015 include the results of operations of Montpelier from August 1, 2015. For additional information on the acquisition of Montpelier, see Note 3, Acquisition of Montpelier. Endurance Holdings writes specialty lines of insurance and reinsurance on a global basis through its wholly-owned operating subsidiaries: Operating Subsidiaries Domicile Endurance Specialty Insurance Ltd. ("Endurance Bermuda") Bermuda Blue Capital Management Ltd., manager of Blue Water Re Ltd. and Blue Water Re II Ltd. Bermuda Endurance Worldwide Insurance Limited ("Endurance U.K.") England Endurance at Lloyd's, managing agent for Lloyd's Syndicate 5151 England Endurance Reinsurance Corporation of America ("Endurance U.S. Reinsurance") Delaware Endurance American Insurance Company ("Endurance American") Delaware Endurance American Specialty Insurance Company ("Endurance American Specialty") Delaware Endurance Risk Solutions Assurance Co. ("Endurance Risk Solutions") Delaware American Agri-Business Insurance Company ("American Agri-Business"), managed by ARMtech Insurance Services, Inc. (together with American Agri-Business, "ARMtech") Texas In addition, as part of the Blue Capital operations Endurance Holdings and Endurance Bermuda together own 33.3% of Blue Capital Reinsurance Holdings Ltd. ("BCRH") and Endurance Bermuda owns 25.1% of Blue Capital Global Reinsurance Fund Limited ("BCGR"). BCRH is a Bermuda-based exempted limited liability holding company managed by BCML that provides fully-collateralized property catastrophe reinsurance and invests in various insurance-linked securities through its wholly-owned Bermuda-based subsidiaries, Blue Capital Re. Ltd. ("Blue Capital Re") and Blue Capital Re ILS Ltd. ("Blue Capital Re ILS"). BCRH's shares are listed on the New York Stock Exchange and the Bermuda Stock Exchange. BCGR is a closed-ended mutual fund incorporated in Bermuda and managed by BCML that serves as the feeder fund for the Blue Capital Global Reinsurance SA-1 cell (the "BCGR Cell"). BCGR's shares are listed on the Specialist Fund Market of the London Stock Exchange and on the Bermuda Stock Exchange.

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	2. Significant accounting policies The consolidated financial statements have been prepared on the basis of accounting principles generally accepted in the United States ("U.S. GAAP") and include the accounts of Endurance Holdings and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The following are significant accounting and reporting policies adopted by the Company: 2. Significant accounting policies, cont'd. (a) Premiums and related expenses The Company's insurance premiums are earned pro rata over the term of the applicable risk period specified in the insurance policy. The Company's insurance policies cover losses occurring or claims made during the term of the policy. Generally, the Company receives a fixed premium which is identified in the policy and is recorded on the inception date of the contract or when premiums are determinable and earned evenly over the policy term. This premium will only adjust if the underlying insured values adjust. Accordingly, the Company monitors the underlying insured values and records additional or return premiums in the period in which amounts are reasonably determinable. The Company's reinsurance premiums are earned in proportion to the amount of reinsurance protection provided over the applicable risk period established in the reinsurance contract. Reinsurance contracts written on a losses occurring basis cover losses which occur during the term of the reinsurance contract, typically 12 months. Accordingly, the Company earns the premium on a losses occurring reinsurance contract evenly over the reinsurance contract term. Reinsurance contracts written on a policies attaching basis cover losses from the underlying insurance policies incepting during the terms of the reinsurance contracts. Losses under a policies attaching reinsurance contract may occur after the end date of the reinsurance contract, so long as they are losses from policies that began during the reinsurance contract period. The Company typically earns the premiums for policies attaching reinsurance contracts over a 24 -month period in proportion to the amount of reinsurance protection provided to reflect the extension of the risk period past the term of the contract and the varying levels of reinsurance protection provided during the reinsurance contract period. In addition to the applicable risk period, the Company's estimate of its reinsurance premiums written is based on the type of reinsurance contracts underwritten. For excess of loss reinsurance contracts, the deposit premium, as defined in the contract, is generally considered to be the best estimate of the reinsurance contract's written premium at inception. The Company earns reinstatement premiums upon the occurrence of a loss under the reinsurance contract. Reinstatement premiums are calculated in accordance with the contract terms based upon the ultimate loss estimate associated with each contract. For proportional reinsurance contracts, the Company estimates premium, commissions and related expenses based on broker and ceding company estimates and also utilizes judgment in establishing proportional reinsurance contract estimates. Premiums on the Company's excess of loss and proportional reinsurance contracts are estimated at the time the business is underwritten. Accordingly, this is the amount the Company records as written premium in the period the reinsurance contract is underwritten. As actual premiums are reported by the ceding companies, management evaluates the appropriateness of the original premium estimates and any adjustments to these estimates are recorded in the period in which they become known. Premiums receivable are recorded at amounts due less any allowance for estimated uncollectible premiums receivable. At December 31, 2015 , the Company had an allowance for estimated uncollectible premiums receivable of $7.4 million ( 2014 - $2.6 million ). Acquisition expenses are costs that vary with and are directly related to the successful production of new and renewal business, and consist principally of commissions and brokerage expenses. Acquisition and general and administrative expenses are shown net of commissions, other fees and expense allowances associated with and earned on ceded business. These costs are deferred and amortized over the periods in which the related premiums are earned. Deferred acquisition costs are limited to their estimated realizable value based on the related unearned premiums. Anticipated net investment income is considered in determining the recoverability of deferred acquisition costs. (b) Reserve for losses and loss expenses The Company’s reserve for losses and loss expenses includes case reserves and reserves for losses incurred but not reported (referred to as "IBNR reserves"). Case reserves are established for losses that have been reported, but not yet paid. IBNR reserves represent a provision for claims that have been incurred but not yet reported to the Company, as well as future loss development on losses already reported, in excess of the case reserves. Case reserves and IBNR reserves are established by management based on reports from reinsurance intermediaries, ceding companies and insureds, and consultations with independent legal counsel. In addition, reserves for IBNR losses and loss expenses are established by management based on reported losses and loss expenses, and actuarially determined estimates of ultimate losses and loss expenses. 2. Significant accounting policies, cont'd. (b) Reserve for losses and loss expenses, cont'd. The Company uses a variety of actuarial methods to estimate the ultimate losses and loss expenses incurred by the Company. One actuarial method used by the Company to estimate reserves for losses and loss expenses is the expected loss ratio approach, which is based on expected results independent of current loss reporting activity. This approach is typically used for immature loss periods (i.e., the current accident year). Another actuarial method used by the Company to estimate reserves for losses and loss expenses is known as the Bornhuetter-Ferguson method. The Bornhuetter-Ferguson method uses an initial loss estimate (expected loss technique) for each accident year by business line and type of contract. Under this method, IBNR is set equal to the initial loss estimate multiplied by the expected percent of loss yet to be reported at each valuation date. In a given quarter, if reported losses are less than expected, then the difference would result in a decrease in estimated ultimate losses. If losses are greater than expected, then the difference would result in an increase in estimated ultimate losses. A third actuarial method used by the Company to estimate reserves for losses and loss expenses is known as the loss development method. The loss development method extrapolates the current value of reported losses to ultimate expected losses by using selected reporting patterns of losses over time. The selected reporting patterns are based on historical information (organized into loss development triangles) and are adjusted to reflect the changing characteristics of the book of business written by the Company. Management uses these multiple actuarial methods, supplemented with professional judgment, to establish the best estimate of reserves for losses and loss expenses. The Company's loss and loss expense reserves are reviewed regularly, and adjustments, if any, are reflected in earnings in the period in which they become known. The establishment of new loss and loss expense reserves or the adjustment of previously recorded loss and loss expense reserves could result in significant positive or negative changes to the Company's financial condition for any particular period. While management believes the Company's estimate of loss and loss expense reserves is reasonable, the ultimate loss experience may not be reliably predicted, and it is possible losses and loss expenses may be materially different than the total reserve for losses and loss expenses recorded by the Company. (c) Reinsurance Reinsurance recoverable on paid and unpaid losses represent estimates of losses and loss expenses that will be recovered from reinsurers. Amounts recoverable from reinsurers are estimated in a manner consistent with the provisions of the reinsurance agreements and consistent with the establishment of the Company's reserve for losses and loss expenses. Ceding commissions earned on ceded business are classified as an offset to acquisition and general and administrative expenses. (d) Investments The Company currently classifies its fixed maturity investments, short-term investments and equity securities as trading or available for sale. Trading securities are carried at estimated fair value, with related net realized and unrealized gains or losses included in earnings. The Company acquired a portfolio of investments classified as trading from Montpelier. In addition, in the fourth quarter of 2015, the Company started designating, on acquisition, certain fixed maturity, short-term and equity investments as trading, rather than as available for sale. The Company has elected to account for trading securities using the fair value option under current accounting guidance, as the Company believes it represents the most meaningful measurement basis for these assets and presents the Company's fixed maturity, short-term and equity investments in a manner consistent with the way in which the Company manages the investment portfolio, which is on a total investment return basis. The Company currently expects to continue to designate, in future periods, on acquisition, certain fixed maturity, short-term and equity investments as trading, rather than as available for sale. As a result, the Company currently expects its fixed maturity, short-term and equity investments balances classified as available for sale to decrease and the trading balance for each of these investments to increase. This change will result in a reduction in other-than-temporary accounting judgments the Company makes and will result in additional volatility in the Company's net income in future periods as net unrealized gains and losses on these investments will be recorded in net income, rather than as a component of accumulated other comprehensive (loss) income in shareholders' equity. 2. Significant accounting policies, cont'd. (d) Investments, cont'd. Available for sale securities are carried at estimated fair value, with related net unrealized gains or losses excluded from earnings and included in shareholders' equity as a component of accumulated other comprehensive (loss) income. Investment transactions are recorded on a trade date basis. The Company determines the fair value of its trading and available for sale investments in accordance with current accounting guidance, which defines fair value and establishes a fair value hierarchy based on inputs to the various valuation techniques used for each fair value measurement. The use of valuation techniques for any given investment requires a significant amount of judgment and consideration of factors specific to the underlying investment. Fair value measurements determined by the Company seek to maximize observable inputs and minimize the use of unobservable inputs. Current accounting guidance establishes three levels as follows: Level 1: Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2: Quoted prices for similar assets in markets that are active, quoted prices for identical or similar assets in markets that are not active or inputs that are observable either directly or indirectly. Level 2 inputs include quoted prices for similar assets or liabilities other than quoted prices in Level 1; quoted prices in markets that are not active; or other inputs that are observable or can be derived principally from or corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3: Unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities. Unobservable inputs reflect the Company's own views about the assumptions that market participants would use in pricing the asset or liability. Level 3 assets and liabilities include financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. The Company determines the estimated fair value of each individual security utilizing the highest level inputs available. Transfers between levels are assumed to occur at the end of each period. If the Company has the intent to sell a fixed maturity or short-term security classified as available for sale in an unrealized loss position or it is more likely than not that the Company will be required to sell the available for sale security, the Company deems the security to be other-than-temporarily impaired and writes down the carrying value of the security to fair value, thereby establishing a new cost basis. The amount of the write-down is recognized in earnings as an other-than-temporary impairment ("OTTI") loss. For fixed maturity and short-term investments classified as available for sale in an unrealized loss position for which a decision to sell has not been made and it is not more likely than not that the Company will be required to sell the security, the Company performs additional reviews to determine whether the investment will recover its amortized cost. If the amortized cost of the Company's fixed maturity and short-term investments classified as available for sale is, based upon the judgment of management, unlikely to be recovered, the Company writes down the investment by the amount representing the credit related portion of the decline in value, thereby establishing a new cost basis. The amount of the write-down is recognized in earnings as an OTTI loss. The new cost basis is not changed for subsequent recoveries in fair value. To the extent the Company determines that the amortized cost of the Company's fixed maturity and short-term investments classified as available for sale is likely to be recovered and the decline in value is related to non-credit factors (such as interest rates, market conditions, etc.) and not due to credit related factors, that remaining non-credit portion of the unrealized loss is recorded as a part of accumulated other comprehensive (loss) income in the shareholders' equity section of the Company's Consolidated Balance Sheets. For equity securities classified as available for sale, the Company considers its ability and intent to hold the equity security in an unrealized loss position for a reasonable period of time to allow for a full recovery. When the Company determines that the decline in value of an equity security is other-than-temporary, the Company reduces the cost of the equity security to its fair value and recognizes the loss in the Consolidated Statements of Income and Comprehensive Income. The new cost basis is not changed for subsequent recoveries in fair value. 2. Significant accounting policies, cont'd. (d) Investments, cont'd. Other investments within the Company's investment portfolio are comprised of (i) hedge funds, private investment funds and other investment funds that generally invest in senior secured bank debt, high yield credit securities, distressed debt, macro strategies, multi-strategy, equity long/short strategies, distressed real estate, and energy sector private equity ("alternative funds") and (ii) high yield loan funds ("specialty funds"). Other investments are accounted for using the equity method of accounting whereby the initial investment is recorded at cost. The carrying values of these investments are increased or decreased to reflect the Company's share of income or loss, which is included in net investment income, and are decreased for dividends. Due to the timing of the delivery of the final valuations reported by the managers of certain of our alternative and specialty funds, our investments in those funds are estimated based on the most recently available information including period end valuation statements, period end estimates, or, in some cases, prior month or quarter valuation statements. (e) Cash equivalents and short-term investments Cash equivalents include highly liquid short-term deposits and securities with maturities of ninety days or less at the time of purchase. Cash equivalents are valued at amortized cost, which approximates fair value due to the short-term, liquid nature of these securities. Deposits and securities with maturities greater than ninety days and less than one year are classified as short-term investments. (f) Intangible assets Identifiable intangible assets are amortized in accordance with their useful lives. Goodwill and intangible assets with indefinite useful lives are not amortized but are tested for impairment annually at the beginning of the fourth quarter, or more often if impairment indicators arise. In making an assessment of the value of its goodwill and intangible assets, the Company uses both market based and non-market based valuations. Assumptions underlying these valuations include forecasts of discounted future cash flows and future profits and comparable transactions observed in the market, in addition to an analysis of the Company’s stock price relative to both its book value and its net income. (g) Offering and registration costs Offering and registration costs incurred in connection with equity offerings, including investment banking fees and legal fees, are deducted from the proceeds of the offerings. (h) Foreign exchange Assets and liabilities of foreign operations whose functional currency is not the United States dollar are translated at exchange rates in effect at the balance sheet date. Revenues and expenses of such foreign operations are translated at weighted average exchange rates during the year. The effect of the translation adjustments for foreign operations is included in accumulated other comprehensive (loss) income, net of applicable deferred income taxes. Other monetary assets and liabilities denominated in foreign currencies are revalued at the exchange rates in effect at the balance sheet date with the resulting net foreign exchange gains and losses included in earnings. Revenues and expenses denominated in foreign currencies are translated at the prevailing exchange rate on the transaction date. (i) Derivatives Current accounting guidance requires the recognition of all derivative financial instruments including embedded derivative instruments, as either assets or liabilities in the Consolidated Balance Sheets at fair value. The Company may use various derivative instruments such as foreign exchange forward, future and option contracts; industry loss warranty swaps; interest rate futures, swaps, swaptions, and options; credit default swaps; LIBOR swaps; commodity futures and options; weather swaps and options; loss development covers; and to-be-announced mortgage-backed securities. These derivative instruments are used to manage exposure to interest rate and currency risk, to enhance the efficiency of the Company's investment portfolio, to economically hedge certain risks, and as part of its weather risk management business. Except for a cash flow hedge entered into in 2004 as disclosed in Note 9, Derivatives, these derivative instruments do not qualify, and are not designated, as hedges. Derivatives are recorded at fair value with changes in fair value and any gains or losses are recognized in net realized and unrealized gains, net foreign exchange losses, or other underwriting loss in the Consolidated Statements of Income and Comprehensive Income. 2. Significant accounting policies, cont'd. (i) Derivatives, cont'd. Margin balances required of counterparties are included in cash and cash equivalents. Where the Company has entered into master netting agreements with counterparties, or the Company has the legal and contractual right to offset positions, the derivative positions may be netted by the counterparty. (j) Income taxes The Company accounts for income taxes for its subsidiaries operating in taxable jurisdictions. Deferred income taxes reflect the net tax effect of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. A valuation allowance is provided when it is more likely than not that some portion of the deferred tax assets will not be realized. The accounting guidance allows for the recognition of tax benefits of uncertain tax positions only where the position is more likely than not to be sustained assuming examination by tax authorities. A liability is established for any tax benefit claimed in a tax return in excess of this threshold. Income tax related interest and penalties are included as income tax expense. (k) Stock compensation and other stock plans The Company has a share-based employee and non-employee director equity incentive plan ("2007 Equity Incentive Plan") and other share plans, which are described more fully in Note 16, Stock-based employee compensation and other stock plans. The fair value of the compensation cost incurred under these plans is measured at the grant date and is expensed over the period for which the employee is required to provide services in exchange for the award. Forfeiture benefits are estimated at the time of grant and incorporated in the determination of share-based compensation costs. Awards under the 2007 Equity Incentive Plan generally vest over four years for employees and one year for non-employee directors. (l) Earnings per share The two-class method utilized by the Company is an earnings allocation formula that determines earnings per share for the holders of Endurance Holdings' ordinary shares (also referred to as "common shares") and participating common shares, which includes unvested restricted shares and restricted share units that receive cash dividends, according to dividends declared (or accumulated) and participation rights in undistributed earnings. Net income available to common and participating common shareholders is reduced by the amount of dividends declared in the current period and by the contractual amount of dividends that must be paid for the current period related to the Company's common and participating common shares. Any remaining undistributed earnings are allocated to the common and participating common shareholders to the extent that each security may share in earnings as if all of the earnings for the period had been distributed. In periods of loss, no losses are allocated to participating common shareholders. Instead, all such losses are allocated solely to the common shareholders. Basic earnings per common share are calculated by dividing net income available to common shareholders by the weighted average number of common shares outstanding. The weighted average number of common shares excludes any dilutive effect of outstanding options and convertible securities such as unvested restricted shares and restricted share units. Diluted earnings per common share are based on the weighted average number of common shares and assumes the exercise of all dilutive stock options and the vesting or conversion of all convertible securities such as unvested restricted shares using the two-class method described above. (m) Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported and disclosed amounts 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. Actual results could differ from those estimates. 2. Significant accounting policies, cont'd. (n) Variable interest entity Entities that do not have sufficient equity at risk to allow the entity to finance its activities without additional financial support or in which the equity investors, as a group, do not have the characteristic of a controlling financial interest are referred to as variable interest entities ("VIE"). A VIE is consolidated by the variable interest holder that is determined to have the controlling financial interest (primary beneficiary) as a result of having both the power to direct the activities of a VIE that most significantly impact the VIE's economic performance and the obligation to absorb losses or right to receive benefits from the VIE that could potentially be significant to the VIE. The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure, contractual terms, nature of the VIE's operations and purpose and the Company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE. The Company reassesses its VIE determination with respect to an entity on an ongoing basis. See also Note 4, Investments. (o) Non-controlling interests The Company accounts for non-controlling interests in the shareholders' equity section of the Company's Consolidated Balance Sheets in accordance with current accounting guidance regarding consolidation. Net income attributable to non-controlling interest is presented separately in the Company's Consolidated Statements of Income and Comprehensive Income. (p) Reclassifications Certain comparative information has been reclassified to conform to current year presentation. (q) Recent accounting pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-09, "Revenue from Contracts with Customers" ("ASU 2014-09"). ASU 2014-09 provides comprehensive guidance on the recognition of revenue from customers arising from the transfer of goods and services. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for these goods or services. ASU 2014-09 also provides guidance on accounting for certain contract costs and will also require new disclosures. ASU 2014-09 was to be effective for public business entities in annual and interim periods beginning after December 15, 2016, however, in July 2015, the FASB decided to defer by one year the effective dates of ASU 2014-09, and as a result, ASU 2014-09 will be effective for public business entities in annual and interim period beginning after December 15, 2017. Early adoption is permitted. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company's Consolidated Financial Statements. In February 2015, the FASB issued ASU 2015-02, "Amendments to the Consolidation Analysis" ("ASU 2015-02"). Under ASU 2015-02, all legal entities are required to evaluate whether they should consolidate certain legal entities. ASU 2015-02 set forth amendments: (1) modifying the evaluation of whether limited partnerships and similar legal entities are variable interest entities ("VIEs") or voting interest entities; (2) eliminating the presumption that a general partner should consolidate a limited partnership; (3) affecting the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships; and (4) providing a scope exception from consolidation guidance for certain reporting entities. ASU 2015-02 is effective for public business entities for annual and interim periods beginning after December 15, 2015. Early adoption is permitted. ASU 2015-02 may be applied retrospectively or by using a modified retrospective approach by recording a cumulative-effect adjustment to equity as of the beginning of the year of adoption. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company's Consolidated Financial Statements. 2. Significant accounting policies, cont'd. (q) Recent accounting pronouncements, cont'd. In April 2015, the FASB issued ASU 2015-03, "Simplifying the Presentation of Debt Issuance Costs" ("ASU 2015-03"). The objective of ASU 2015-03 is to simplify the presentation of debt issuance costs by requiring direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in ASU 2015-03. ASU 2015-03 is effective for public business entities in annual and interim periods beginning after December 15, 2015. Early adoption is permitted. ASU 2015-03 should be applied retrospectively, and upon transition, applicable disclosures for a change in accounting principle shall be provided, including the transition method, a description of the prior period information that has been retrospectively adjusted, and the effect of the change on the applicable financial statement line items. The Company retrospectively adopted this standard effective October 1, 2015. Debt issuance costs as at December 31, 2015, 2014 and 2013 of $3.2 million , $4.1 million , and $5.1 million , respectively, have been reclassified from other assets to debt in the Company's Consolidated Balance Sheets. This standard had no impact on the Company's Consolidated Statements of Income and Comprehensive Income. In May 2015, the FASB issued ASU 2015-07, "Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent)" ("ASU 2015-07"). The objective of ASU 2015-07 is to remove the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using net asset value per share. ASU 2015-07 is effective for public business entities in annual and interim periods beginning after December 15, 2015. Early adoption is permitted. ASU 2015-07 should be applied retrospectively. The Company retrospectively adopted this standard effective October 1, 2015. The Company's other investments were removed from the fair value hierarchy tables for the years ended December 31, 2015 and 2014 in Note 5, Fair value. This standard had no impact on the Company's Consolidated Financial Statements. In May 2015, the FASB issued ASU 2015-09, "Disclosures about Short-Duration Contracts" ("ASU 2015-09"). The objective of ASU 2015-09 is to make targeted improvements to disclosure requirements for insurance companies that issue short-duration contracts. The guidance requires additional disclosures of claims development tables, frequency of reported claims, and history of claims duration. This information is required to be disaggregated so that useful information is not obscured by either the inclusion of a large amount of insignificant detail, or the aggregation of items that have significantly different characteristics. ASU 2015-09 is effective for public business entities in annual periods beginning after December 15, 2015, and interim periods within annual periods beginning after December 15, 2016. Early adoption is permitted. ASU 2015-09 should be applied retrospectively. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company's Consolidated Financial Statements. In September 2015, the FASB issued ASU 2015-16, "Simplifying the Accounting for Measurement-Period Adjustments" ("ASU 2015-16"). ASU 2015-16 eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Instead, an acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. ASU 2015-16 is effective for public business entities in annual periods beginning after December 15, 2015, and interim periods within annual periods beginning after December 15, 2015. Early adoption is permitted. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company's Consolidated Financial Statements.

Acquisition of Montpelier

Acquisition of Montpelier	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	3. Acquisition of Montpelier On March 31, 2015, the Company announced the signing of a definitive agreement and plan of merger (the "Merger Agreement") with Montpelier and Millhill Holdings Ltd., a direct, wholly-owned subsidiary of the Company ("Merger Sub"), under which Endurance Holdings, through Merger Sub, acquired all of the outstanding common shares of Montpelier. The acquisition of Montpelier was completed on July 31, 2015 (the "Closing Date"). Prior to the closing of the acquisition, Montpelier was a publicly traded company listed on the New York Stock Exchange and headquartered in Bermuda. As of the close of trading on July 31, 2015, the common shares of Montpelier ceased trading. 3. Acquisition of Montpelier, cont'd. The aggregate consideration for the transaction consisted of the issuance of 20.7 million of the Company’s ordinary shares valued at $1.4 billion and $451.1 million of cash. The cash consideration was funded through a pre-closing dividend from Montpelier of $9.89 per common share, or $451.1 million (the "Special Dividend"). In connection with the acquisition of Montpelier, the Company incurred transaction and integration related expenses of $76.6 million in the year ended December 31, 2015 , which included $19.5 million related to transaction costs, including due diligence, legal, accounting and investment banking fees and expenses, $4.4 million of costs related to the integration of Montpelier and the Company, and $52.7 million of compensation-related costs associated with terminating employees of Montpelier. These expenses have all been reported as a component of corporate expenses. Purchase price The Company's total purchase price for Montpelier at July 31, 2015 was calculated as follows: Consideration paid by Endurance Holdings Number of Montpelier common shares outstanding immediately prior to the closing of the acquisition 43,827,753 Exchange ratio 0.472 Total Company ordinary shares 20,686,699 Company ordinary share closing price on July 31, 2015 $ 69.49 Total value of Company ordinary shares $ 1,437,519 Fair value of restricted share units attributable to service period prior to Closing Date (1) $ 33,327 Total consideration $ 1,470,846 Special Dividend paid by Montpelier Number of Montpelier common shares and restricted share units eligible for special dividend 45,611,810 Special dividend paid per Montpelier common share and restricted share unit $ 9.89 Total special dividend consideration paid to Montpelier common shareholders and Montpelier equity award holders $ 451,101 Total consideration received by Montpelier common shareholders and Montpelier equity award holders $ 1,921,947 Less: Special Dividend paid by Montpelier (451,101 ) Net purchase price $ 1,470,846 (1) Outstanding Montpelier restricted share units were assumed by the Company and adjusted as of the Closing Date to represent the right to receive 0.472 Company ordinary shares for each outstanding Montpelier restricted share unit rounded down to the next whole number of Company ordinary shares. The fair value of the Montpelier restricted share units was determined based on the closing price of the Company's ordinary shares on the Closing Date. The resulting fair value of the restricted share units was apportioned as purchase consideration based on service provided to Montpelier as of the Closing Date with the remaining fair value of these restricted share units to be recognized prospectively over the restricted share units' remaining vesting period. Fair value of net assets acquired and liabilities assumed The purchase price was allocated to the acquired assets and liabilities of Montpelier based on estimated fair values on July 31, 2015, the Closing Date, as detailed below. The Company recognized goodwill of $87.6 million primarily attributable to Montpelier's assembled workforce and synergies expected to result upon integration of Montpelier into the Company's operations. The Company estimates that none of the goodwill that was recorded will be deductible for income tax purposes. The allocation of the purchase price is based on information that was available to management at the time the consolidated financial statements were prepared. The allocation may change as additional information becomes available within the measurement period, which cannot exceed 12 months from the acquisition date. The fair value recorded for these items may be subject to adjustments, which may impact the individual amounts recorded for assets acquired and liabilities assumed, as well as the residual goodwill. The Company identified finite lived intangible assets of $293.2 million , which will be amortized over a weighted average period of 8 years, identifiable indefinite lived intangible assets of $57.6 million , and certain other 3. Acquisition of Montpelier, cont'd. adjustments to the fair values of the assets acquired, liabilities assumed and shareholders' equity of Montpelier at July 31, 2015 as summarized in the table below: Montpelier shareholders' equity attributable to controlling interest prior to Special Dividend $ 1,560,255 Cash and cash equivalents (Special Dividend on Montpelier common shares and Montpelier equity awards) (451,101 ) Adjusted shareholders' equity of Montpelier as of July 31, 2015 1,109,154 Adjustments for fair value, by applicable balance sheet caption: Assets: Fixed maturity investments, trading at fair value (11,100 ) Deferred acquisition costs (91,713 ) Reinsurance recoverable on unpaid losses (675 ) Other assets (12,459 ) Liabilities: Reserve for losses and loss expenses 10,822 Debt 21,123 Deferred tax liability (18,346 ) Equity: Non-controlling interest 25,615 Total adjustments for fair value by applicable balance sheet caption (76,733 ) Adjustments for fair value of the identifiable intangible assets: Identifiable indefinite lived intangible assets (insurance licenses, Lloyd's syndicate capacity and asset management agreements) 57,600 Identifiable finite lived intangible assets (non-contractual relationships, Lloyd's syndicate distribution channel, renewal rights, value of business acquired ("VOBA"), trade names, non-compete agreements and asset management agreements) 293,200 Total adjustments for fair value by applicable balance sheet caption and identifiable intangible assets 274,067 Estimated fair value of net assets acquired and identifiable intangible assets 1,383,221 Total consideration paid by Endurance Holdings 1,470,846 Estimated total consideration over the fair value of net assets acquired assigned to goodwill $ 87,625 An explanation of the significant fair value adjustments is as follows: • Fixed maturity investments, trading at fair value - To reflect certain investments at fair value; • Deferred acquisition costs - To eliminate Montpelier's deferred acquisition costs; • Other assets - To eliminate deferred debt issuance costs related to Montpelier's existing senior notes and to write off Montpelier's fixed assets and goodwill; • Reserve for losses and loss expenses - To reflect a decrease in net losses and loss expenses due to the addition of a market based risk margin, which represents the cost of capital required by a market participant to assume the net losses and loss expenses of Montpelier, offset by a deduction that represents the discount due to the present value calculation of the unpaid losses and loss expenses based on the expected payout of the net unpaid losses and loss expenses; • Debt - To reflect Montpelier's existing senior notes and trust preferred securities at fair value using indicative market pricing obtained from third-party service providers; • Deferred tax liability - To reflect the deferred tax liability on identifiable intangible assets; • Non-controlling interest - To reflect Montpelier's non-controlling interest at fair value; and • Identifiable indefinite lived and finite lived intangible assets - To establish the fair value of identifiable intangible assets related to the acquisition of Montpelier described in detail below. 3. Acquisition of Montpelier, cont'd. Identifiable intangible assets at July 31, 2015 consisted of the following, and are included in goodwill and other intangible assets on the Company's consolidated balance sheets: Amount Economic Useful Life Key non-contractual relationships $ 71,800 10 Other non-contractual relationships 22,400 3 Trade names 1,800 Various Insurance licenses 1,900 Indefinite Non-compete agreements 5,700 Various Lloyd's syndicate capacity 48,300 Indefinite Lloyd's syndicate distribution channel 18,400 10 Renewal rights 82,100 15 VOBA 88,400 2 Asset management agreements 10,000 Various Identifiable intangible assets at July 31, 2015 $ 350,800 An explanation of the identifiable intangible assets is as follows: • Key non-contractual relationships - these relationships included Montpelier's top brokers and consideration was given to the expectation of the renewal of these relationships and the associated expenses; • Other non-contractual relationships - these relationships consisted of Montpelier's brokers with the exception of those top brokers previously listed above as key non-contractual relationships and consideration was given to the expectation of the renewal of these relationships and the associated expenses; • Trade names - represents the value of the Montpelier and Blue Capital brands acquired; • Insurance licenses - the value of insurance licenses acquired providing the ability to write reinsurance in 15 states of the U.S.; • Non-compete agreements - represent non-compete agreements with key employees of Montpelier; • Lloyd's syndicate capacity - the value of Lloyd's syndicate capacity, which represents Montpelier's authorized premium income limit to write insurance business in the Lloyd's marketplace; • Lloyd's syndicate distribution channel - the value of sales of insurance policies that result directly from relationships between Lloyd's and the brokers in the Lloyd's marketplace; • Renewal rights - the value of policy renewal rights taking into consideration written premium on assumed retention ratios and the insurance cash flows and the associated equity cash flows from these renewal policies over the expected life of the renewals; • VOBA - the expected future losses and expenses associated with the policies that were in-force as of the Closing Date of the transaction were estimated and compared to the future premium remaining expected to be earned. The difference between the risk-adjusted future loss and expenses, discounted to present value and the unearned premium reserve, was estimated to be the VOBA; and • Asset management contracts - represents the value of the Blue Capital asset management contracts acquired. 3. Acquisition of Montpelier, cont'd. Financial results The following table summarizes the results of Montpelier since July 31, 2015 that have been included in the Company's Consolidated Statement of Income and Comprehensive Income for the year ended December 31, 2015 : For the period from July 31, 2015 to December 31, 2015 Total revenues $ 225,899 Net income attributable to the Company's common shareholders (1) 54,768 (1) Includes $52.7 million of compensation-related costs associated with terminating employees of Montpelier. Supplemental pro forma information The following table presents unaudited pro forma consolidated financial information for the years ended December 31, 2015 and 2014 and assumes the acquisition of Montpelier occurred on January 1, 2014. The unaudited pro forma consolidated financial information is provided for informational purposes only and is not necessarily, and should not be assumed to be, an indication of the results that would have been achieved had the transaction been completed as of January 1, 2014 or that may be achieved in the future. The unaudited pro forma consolidated financial information does not give consideration to the impact of possible revenue enhancements, expense efficiencies, synergies or asset dispositions that may result from the acquisition of Montpelier. In addition, unaudited pro forma consolidated financial information does not include the effects of costs associated with any restructuring or integration activities resulting from the acquisition of Montpelier, as they are nonrecurring. Year Ended December 31, 2015 2014 Total revenues $ 2,452,410 $ 2,668,604 Net income available to Endurance Holdings' common shareholders 443,817 388,371 Among other adjustments, and in addition to the fair value adjustments and recognition of goodwill and identifiable intangible assets noted above, other material nonrecurring pro forma adjustments directly attributable to the acquisition of Montpelier principally included certain adjustments to recognize transaction related costs, align accounting policies, amortize fair value adjustments, amortize identifiable indefinite lived intangible assets and recognize related tax impacts.

Investments

Investments	12 Months Ended
	Dec. 31, 2015
Investments [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	4. Investments Composition of Net Investment Income and of Invested Assets The components of net investment income for the years ended December 31, 2015 , 2014 and 2013 are as follows: 2015 2014 2013 Fixed income investments $ 132,786 $ 118,084 $ 109,118 Equity securities 8,209 5,689 3,956 Other investments (13,553 ) 19,609 64,321 Cash and cash equivalents 2,870 2,445 2,752 $ 130,312 $ 145,827 $ 180,147 Investment expenses (16,486 ) (14,284 ) (13,931 ) Net investment income $ 113,826 $ 131,543 $ 166,216 4. Investments, cont'd. Contractual maturities of the Company's fixed maturity and short-term investments are shown below as of December 31, 2015 and 2014 . Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. December 31, 2015 December 31, 2014 Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 622,070 $ 622,248 $ 126,921 $ 127,821 Due after one year through five years 2,005,456 1,995,502 1,627,154 1,632,259 Due after five years through ten years 683,147 676,932 474,959 479,138 Due after ten years 33,168 34,651 43,314 46,720 Residential mortgage-backed securities 1,301,083 1,311,373 1,149,536 1,175,006 Commercial mortgage-backed securities 817,570 812,886 960,598 979,419 Collateralized loan and debt obligations 419,795 405,128 247,510 248,011 Asset-backed securities 510,540 507,255 411,529 413,221 Total $ 6,392,829 $ 6,365,975 $ 5,041,521 $ 5,101,595 The following table summarizes the fair value of the fixed maturity investments, short-term investments and equity securities classified as trading at December 31, 2015 . The Company had no securities classified as trading as of December 31, 2014 . December 31, 2015 Fixed maturity investments U.S. government and agencies securities $ 319,674 U.S. state and municipal securities 5,559 Foreign government securities 49,861 Government guaranteed corporate securities 38,201 Corporate securities 532,192 Residential mortgage-backed securities 258,574 Commercial mortgage-backed securities 127,124 Collateralized loan and debt obligations (1) 103,219 Asset-backed securities 152,756 Total fixed maturity investments 1,587,160 Short-term investments 394,111 Total fixed income investments $ 1,981,271 Equity securities Equity investments $ 48 Preferred equity investments 553 Short-term fixed income fund 14,628 Total equity securities $ 15,229 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $38.5 million at December 31, 2015 . 4. Investments, cont'd. In addition to the Company's fixed maturity, short-term and equity investments, the Company invests in alternative funds and specialty funds. The Company's alternative funds and specialty funds are recorded on the Company's balance sheet as "other investments". At December 31, 2015 and 2014 , the Company had invested, net of capital returned, a total of $737.1 million and $387.2 million , respectively, in other investments. At December 31, 2015 and 2014 , the carrying value of other investments was $872.6 million and $541.5 million , respectively. The following table summarizes the composition and redemption restrictions of other investments as of December 31, 2015 and 2014 : December 31, 2015 Market Value Unfunded Commitments Ineligible for Redemption in 2016 Alternative funds Hedge funds $ 704,966 $ — $ 57,876 Private investment funds 80,690 102,070 80,690 Other investment funds 23,465 30,000 24,958 Total alternative funds 809,121 132,070 163,524 Specialty funds High yield loan funds 63,496 — — Total specialty funds 63,496 — — Total other investments $ 872,617 $ 132,070 $ 163,524 December 31, 2014 Market Value Unfunded Commitments Ineligible for Redemption in 2015 Alternative funds Hedge funds $ 411,280 $ — $ 10,580 Private investment funds 74,664 70,542 74,664 Total alternative funds 485,944 70,542 85,244 Specialty funds High yield loan funds 55,510 — — Total specialty funds 55,510 — — Total other investments $ 541,454 $ 70,542 $ 85,244 Hedge funds – The redemption frequency of the hedge funds range from monthly to biennially with notice periods from 30 to 90 days. Over one year, it is estimated that the Company can liquidate approximately 91.8% of the hedge fund portfolio, with the remainder over the following two years. Private investment funds – The Company generally has no right to redeem its interest in any private investment funds in advance of dissolution of the applicable partnership. Instead, the nature of these investments is that distributions are received by the Company in connection with the distribution of income or the liquidation of the underlying assets of the applicable limited partnership. It is estimated that the majority of the underlying assets of the limited partnerships would liquidate over 5 to 10 years from inception of the limited partnership. A secondary market, with unpredictable liquidity, exists for limited partner interests in private investment funds. Other investment funds – Other investment funds includes funds on deposit with Lloyd's, which are restricted, and the Company's investment in BCGR, which represents the net liability of the Company's investment in BCGR that has not been deployed into the BCGR cell. High yield loan funds – There are generally no restrictions on the Company's right to redeem its interest in high yield loan funds with the exception of certain redemption frequency and notice requirements. The redemption frequency of these funds ranges from monthly to quarterly with notice periods from 30 to 90 days. 4. Investments, cont'd. Net Realized and Unrealized Gains Realized and unrealized gains and losses are recognized in earnings using the first in, first out method. The analysis of gross realized gains and losses, net unrealized gains and losses on trading securities, intangible asset impairment loss, and the change in the fair value of investment-related derivative financial instruments for the years ended December 31, 2015 , 2014 and 2013 are as follows: 2015 2014 2013 Gross realized gains on investment sales $ 65,881 $ 35,921 $ 40,018 Gross realized losses on investment sales (28,636 ) (16,515 ) (25,521 ) Net unrealized losses on trading securities (24,257 ) — — Intangible asset impairment loss (1) — (5,450 ) — Change in fair value of derivative financial instruments (2) (328 ) 327 667 Net realized and unrealized gains $ 12,660 $ 14,283 $ 15,164 (1) For additional information on the Company's intangible assets, see Note 11, Goodwill and intangible assets. (2) For additional information on the Company's derivative financial instruments, see Note 9, Derivatives. Unrealized Gains and Losses The Company classifies some of its investments in fixed maturity investments, short-term investments and equities as available for sale. The amortized cost, fair value and related gross unrealized gains and losses on the Company's securities classified as available for sale at December 31, 2015 and 2014 are as follows: December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity investments U.S. government and agencies securities $ 499,386 $ 2,561 $ (3,153 ) $ 498,794 U.S. state and municipal securities 16,908 120 (181 ) 16,847 Foreign government securities 110,893 803 (581 ) 111,115 Government guaranteed corporate securities 19,248 311 (7 ) 19,552 Corporate securities 1,323,276 5,698 (11,232 ) 1,317,742 Residential mortgage-backed securities 1,041,540 16,400 (5,141 ) 1,052,799 Commercial mortgage-backed securities 689,078 4,737 (8,053 ) 685,762 Collateralized loan and debt obligations (1) 304,915 796 (3,802 ) 301,909 Asset-backed securities 356,753 585 (2,839 ) 354,499 Total fixed maturity investments $ 4,361,997 $ 32,011 $ (34,989 ) $ 4,359,019 Short-term investments 25,657 28 — 25,685 Total fixed income investments $ 4,387,654 $ 32,039 $ (34,989 ) $ 4,384,704 Equity securities Equity investments $ 418,822 $ 6,834 $ (31,875 ) $ 393,781 Emerging market debt funds 61,874 — (5,453 ) 56,421 Convertible funds 46,331 — (146 ) 46,185 Preferred equity investments 15,275 1,946 (151 ) 17,070 Short-term fixed income fund 127 1 — 128 Total equity securities $ 542,429 $ 8,781 $ (37,625 ) $ 513,585 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $11.4 million . 4. Investments, cont'd. December 31, 2014 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity investments U.S. government and agencies securities $ 582,970 $ 6,471 $ (2,030 ) $ 587,411 U.S. state and municipal securities 39,340 191 (118 ) 39,413 Foreign government securities 239,217 2,983 (1,664 ) 240,536 Government guaranteed corporate securities 47,436 675 (9 ) 48,102 Corporate securities 1,354,370 12,742 (5,650 ) 1,361,462 Residential mortgage-backed securities 1,149,536 27,542 (2,072 ) 1,175,006 Commercial mortgage-backed securities 960,598 21,374 (2,553 ) 979,419 Collateralized loan and debt obligations (1) 247,510 1,449 (948 ) 248,011 Asset-backed securities 411,529 2,265 (573 ) 413,221 Total fixed maturity investments $ 5,032,506 $ 75,692 $ (15,617 ) $ 5,092,581 Short-term investments 9,015 — (1 ) 9,014 Total fixed income investments $ 5,041,521 $ 75,692 $ (15,618 ) $ 5,101,595 Equity securities Equity investments $ 176,167 $ 29,660 $ (3,292 ) $ 202,535 Emerging market debt funds 60,826 — (676 ) 60,150 Convertible funds 46,331 — (220 ) 46,111 Preferred equity investments 13,858 2,022 (44 ) 15,836 Short-term fixed income fund 6,740 — (4 ) 6,736 Total equity securities $ 303,922 $ 31,682 $ (4,236 ) $ 331,368 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $15.2 million . 4. Investments, cont'd. The following tables summarize, for all available for sale securities in an unrealized loss position at December 31, 2015 and 2014 , the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position. Less than 12 months 12 months or greater Total December 31, 2015 Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Fixed maturity investments U.S. government and agencies securities $ (2,175 ) $ 347,024 $ (978 ) $ 16,669 $ (3,153 ) $ 363,693 U.S. state and municipal securities (96 ) 9,662 (85 ) 695 (181 ) 10,357 Foreign government securities (404 ) 31,881 (177 ) 3,966 (581 ) 35,847 Government guaranteed corporate securities (7 ) 1,692 — — (7 ) 1,692 Corporate securities (9,222 ) 830,349 (2,010 ) 51,024 (11,232 ) 881,373 Residential mortgage-backed securities (3,378 ) 365,082 (1,763 ) 79,355 (5,141 ) 444,437 Commercial mortgage-backed securities (6,708 ) 436,387 (1,345 ) 42,246 (8,053 ) 478,633 Collateralized loan and debt obligations (3,107 ) 224,520 (695 ) 48,167 (3,802 ) 272,687 Asset-backed securities (2,624 ) 311,814 (215 ) 12,880 (2,839 ) 324,694 Total fixed income investments $ (27,721 ) $ 2,558,411 $ (7,268 ) $ 255,002 $ (34,989 ) $ 2,813,413 Equity securities Equity investments $ (31,875 ) $ 283,095 $ — $ — $ (31,875 ) $ 283,095 Emerging market debt funds — — (5,453 ) 56,421 (5,453 ) 56,421 Convertible funds (146 ) 46,185 — — (146 ) 46,185 Preferred equity investments (151 ) 7,361 — — (151 ) 7,361 Total equity securities $ (32,172 ) $ 336,641 $ (5,453 ) $ 56,421 $ (37,625 ) $ 393,062 (1) Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive (loss) income at December 31, 2015 . As of December 31, 2015 , 1,310 available for sale securities were in an unrealized loss position aggregating $72.6 million . Of those, 158 securities with aggregated unrealized losses of $12.7 million at December 31, 2015 had been in a continuous unrealized loss position for twelve months or greater. 4. Investments, cont'd. Less than 12 months 12 months or greater Total December 31, 2014 Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Fixed maturity investments U.S. government and agencies securities $ (481 ) $ 155,350 $ (1,549 ) $ 45,993 $ (2,030 ) $ 201,343 U.S. state and municipal securities (47 ) 3,295 (71 ) 6,841 (118 ) 10,136 Foreign government securities (1,378 ) 37,904 (286 ) 4,306 (1,664 ) 42,210 Government guaranteed corporate securities (9 ) 4,598 — — (9 ) 4,598 Corporate securities (4,023 ) 533,139 (1,627 ) 84,278 (5,650 ) 617,417 Residential mortgage-backed securities (260 ) 62,832 (1,812 ) 108,899 (2,072 ) 171,731 Commercial mortgage-backed securities (1,068 ) 180,222 (1,485 ) 78,412 (2,553 ) 258,634 Collateralized loan and debt obligations (876 ) 176,439 (72 ) 6,491 (948 ) 182,930 Asset-backed securities (415 ) 199,205 (158 ) 19,095 (573 ) 218,300 Total fixed maturity investments $ (8,557 ) $ 1,352,984 $ (7,060 ) $ 354,315 $ (15,617 ) $ 1,707,299 Short-term investments (1 ) 1,953 — — (1 ) 1,953 Total fixed income investments $ (8,558 ) $ 1,354,937 $ (7,060 ) $ 354,315 $ (15,618 ) $ 1,709,252 Equity securities Equity investments $ (3,292 ) $ 53,591 $ — $ — $ (3,292 ) $ 53,591 Emerging market debt funds (676 ) 60,150 — — (676 ) 60,150 Convertible funds (220 ) 46,111 — — (220 ) 46,111 Preferred equity investments (44 ) 4,449 — — (44 ) 4,449 Short-term fixed income fund (4 ) 6,736 — — (4 ) 6,736 Total equity securities $ (4,236 ) $ 171,037 $ — $ — $ (4,236 ) $ 171,037 (1) Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive (loss) income at December 31, 2014 . As of December 31, 2014 , 747 available for sale securities were in an unrealized loss position aggregating $19.9 million . Of those, 171 securities with aggregated unrealized losses of $7.1 million at December 31, 2014 had been in a continuous unrealized loss position for twelve months or greater. 4. Investments, cont'd. The increase in gross unrealized losses on the Company's fixed income investments and equity securities at December 31, 2015 compared to December 31, 2014 was primarily due to widening of credit spreads and broad equity market declines during the year, rather than any actual credit losses on these securities. At December 31, 2015 , the Company had the intent to sell certain of the fixed maturity investments and equity securities in an unrealized loss position and therefore recognized in earnings total other-than-temporary impairments of $3.7 million ( 2014 - $0.6 million ; 2013 - $1.6 million ). Other Investments The Company is involved in the normal course of business with VIEs primarily as a passive investor in residential and commercial mortgage-backed securities and through its interests in various other investments that are structured as limited partnerships considered to be third party VIEs. The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure, contractual terms, nature of the VIE's operations and purpose, and the company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE. The Company determined that it was not the primary beneficiary for any of these investments as of December 31, 2015 and 2014 . The Company believes its exposure to loss with respect to these investments is generally limited to the investment carrying amounts reported in the Company's Consolidated Balance Sheets and any unfunded investment commitments. Collateralized Reinsurance Entities As of December 31, 2015 , Endurance Holdings and Endurance Bermuda together owned 33.3% of BCRH's common shares. BCRH is considered a VIE under U.S. GAAP and the Company has determined that it is BCRH's primary beneficiary. As a result, the Company fully consolidates the assets, liabilities and operations of BCRH and its subsidiaries within its Consolidated Financial Statements. The interests in BCRH and its subsidiaries that the Company fully consolidates that are attributable to third-party investors are reported within the Company's Consolidated Financial Statements as non-controlling interests. BCRH's shareholder rights do not include redemption features within the control of the third party shareholders. The Company reassesses its VIE determination with respect to BCRH on an ongoing basis. As of December 31, 2015 , Endurance Bermuda owned 25.1% of BCGR's ordinary shares. BCGR is considered a "voting interest entity" under U.S. GAAP and, because the Company owns less than 50% of its outstanding ordinary shares, the Company does not consolidate BCGR's assets, liabilities or operations within its Consolidated Financial Statements. However, the BCGR Cell and Blue Water Re, the Company's wholly-owned Bermuda-based special purpose insurance vehicle, are considered VIEs under U.S. GAAP and the Company has determined that it is the primary beneficiary of these entities. Therefore, as funds held in BCGR are deployed into the BCGR Cell, and ultimately into Blue Water Re, they are included in the Company's consolidated financial statements. Conversely, as funds previously deployed by BCGR and the BCGR Cell into Blue Water Re are returned to BCGR, they are no longer included in the Company's consolidated financial statements. The interests in the BCGR Cell and Blue Water Re that the Company fully consolidate that are attributable to third-party investors are reported within the Company's consolidated financial statements as non-controlling interests. BCGR's shareholder rights do not include redemption features within the control of the third party shareholders. The Company reassesses its VIE determinations with respect to the BCGR Cell and Blue Water Re on an ongoing basis. The following table summarizes the movements in the non-redeemable non-controlling interests balance from the acquisition date, July 31, 2015, to December 31, 2015 : Five Months Ended December 31, 2015 Non-controlling interests acquired July 31, 2015 $ 258,529 Income attributable to third-party investments in the BCGR Cell 5,526 Income attributable to third-party investments in BCRH 5,490 Net income attributable to non-controlling interests 11,016 Net third-party investments in BCRH 20 Dividends declared by BCRH attributable to non-controlling interests (1,755 ) Non-controlling interests - ending balance $ 267,810

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurement	5. Fair value measurement The Company determines the fair value of its fixed maturity investments, short-term investments, equity securities, debt, and other assets and liabilities in accordance with current accounting guidance, which defines fair value and establishes a fair value hierarchy based on inputs to the various valuation techniques used for each fair value measurement. The Company determines the estimated fair value of each individual security utilizing the highest level inputs available. Valuation inputs by security type may include the following: • Government and agencies fixed maturity securities – These securities are generally priced by pricing services or index providers. The pricing services or index providers may use current market trades for securities with similar quality, maturity and coupon. If no such trades are available, the pricing service typically uses analytical models which may incorporate option adjusted spreads, daily interest rate data and market/sector news. The Company generally classifies the fair values of government and agencies securities in Level 2. Current issue U.S. government securities are generally valued based on Level 1 inputs, which use the market approach valuation technique. • Government guaranteed corporate fixed maturity securities – These securities are generally priced by pricing services or index providers. The pricing service or index providers may use current market trades for securities with similar quality, maturity and coupon. If no such trades are available, the pricing service typically uses analytical spread models which may incorporate inputs from the U.S. treasury curve or LIBOR. The Company generally classifies the fair values of its government guaranteed corporate securities in Level 2. • Corporate fixed maturity securities – These securities are generally priced by pricing services or index providers. The pricing services or index providers typically use discounted cash flow models that incorporate benchmark curves for treasury, swap and high issuance credits. Credit spreads are developed from current market observations for like or similar securities. The Company generally classifies the fair values of its corporate securities in Level 2. • Equity securities – These securities are generally priced by pricing services or index providers. Depending on the type of underlying equity security or equity fund, the securities are priced by pricing services or index providers based on quoted market prices in active markets or through a discounted cash flow model that incorporates benchmark curves for treasury, swap and credit for like or similar securities. The Company generally classifies the fair values of its equity securities in Level 1 or 2. • Structured securities including agency and non-agency, residential and commercial mortgage, asset-backed securities and collateralized loan and debt obligations – These securities are generally priced by broker/dealers. Broker/dealers may use current market trades for securities with similar qualities. If no such trades are available, inputs such as bid and offer, prepayment speeds, the U.S. treasury curve, swap curve and cash settlement may be used in a discounted cash flow model to determine the fair value of a security. The Company generally classifies the fair values of its structured securities in Level 2. • Other assets and liabilities – A portion of other assets and liabilities are composed of a variety of derivative instruments used to enhance the efficiency of the investment portfolio and economically hedge certain risks. These instruments are generally priced by pricing services, broker/dealers and/or recent trading activity. The market value approach valuation technique is used to estimate the fair value for these derivatives based on significant observable market inputs. Certain derivative instruments are priced by pricing services based on quoted market prices in active markets. These derivative instruments are generally classified in Level 1. Other derivative instruments are priced using industry valuation models and are considered Level 2, as the inputs to the valuation model are based on observable market inputs. Also included in this line item are proprietary, non-exchange traded derivative-based risk management products primarily used to address weather and energy risks. The trading market for these weather derivatives are generally linked to energy and agriculture commodities, weather and other natural phenomena. In instances where market prices are not available, the Company uses industry or internally developed valuation techniques such as spread option, Black Scholes, quanto and simulation modeling to determine fair value and classifies these in Level 3. These models may reference prices for similar instruments. • Debt – Outstanding debt consists of the Company's 7% Senior Notes due July 15, 2034 and 4.7% Senior Notes due October 15, 2022 (the "Senior Notes") and the Trust Preferred Securities. The fair values of these securities were obtained from a third party pricing service and pricing was based on the spread above the risk-free yield curve. These spreads are generally obtained from the new issue market, secondary trading and broker-dealer quotes. As these spreads and the yields for the risk-free yield curve are observable market inputs, the fair values of the Senior Notes and the Trust Preferred Securities are classified in Level 2. 5. Fair value measurement, cont'd. The carrying values of cash and cash equivalents, accrued investment income, other investments, net receivable on sales of investments, net payable on purchases of investments, the amount outstanding under the BCRH Credit Agreement and other financial instruments not described above approximated their fair values at December 31, 2015 and 2014 . The following table sets forth the Company's fixed maturity investments, equity securities, short-term investments, other assets and liabilities and debt categorized by the level within the hierarchy in which the fair value measurements fall at December 31, 2015 : Fair Value Measurements at December 31, 2015 Total at December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Fixed maturity investments U.S. government and agencies securities $ 818,468 $ 37,741 $ 780,727 $ — U.S. state and municipal securities 22,406 — 22,406 — Foreign government securities 160,976 — 160,976 — Government guaranteed corporate securities 57,753 — 57,753 — Corporate securities 1,849,934 — 1,739,002 110,932 Residential mortgage-backed securities 1,311,373 — 1,311,373 — Commercial mortgage-backed securities 812,886 — 812,174 712 Collateralized loan and debt obligations 405,128 — 404,319 809 Asset-backed securities 507,255 — 507,255 — Total fixed maturity investments 5,946,179 37,741 5,795,985 112,453 Equity securities Equity investments 393,829 260,330 133,499 — Emerging market debt funds 56,421 — 56,421 — Convertible funds 46,185 — 46,185 — Preferred equity investments 17,623 — 17,623 — Short-term fixed income fund 14,756 14,756 — — Total equity securities 528,814 275,086 253,728 — Short-term investments 419,796 — 419,796 — Other assets (see Note 9) 68,892 4 27,385 41,503 Total assets $ 6,963,681 $ 312,831 $ 6,496,894 $ 153,956 Liabilities Other liabilities (see Note 9) $ 46,088 $ — $ 4,059 $ 42,029 Debt 737,974 — 737,974 — Total liabilities $ 784,062 $ — $ 742,033 $ 42,029 During the year ended December 31, 2015 , $131.2 million of investments, consisting primarily of corporate securities acquired from Montpelier, were transferred into Level 3 as no observable inputs were available, and $12.4 million of primarily collateralized loan and debt obligations, asset-backed and commercial mortgage-backed securities were transferred out of Level 3 to Level 2 during the year as market activity for these securities increased and observable inputs became available. During the year ended December 31, 2015 , $11.8 million of U.S. government and agencies securities were transferred from Level 1 to Level 2 as they no longer qualified as on the run U.S. treasury securities. 5. Fair value measurement, cont'd. The following table sets forth the Company's fixed maturity investments, equity securities, short-term investments, other assets and liabilities and debt categorized by the level within the hierarchy in which the fair value measurements fall at December 31, 2014 : Fair Value Measurements at December 31, 2014 Total at December 31, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Fixed maturity investments U.S. government and agencies securities $ 587,411 $ 105,121 $ 482,290 $ — U.S. state and municipal securities 39,413 — 39,413 — Foreign government securities 240,536 — 240,536 — Government guaranteed corporate securities 48,102 — 48,102 — Corporate securities 1,361,462 — 1,358,960 2,502 Residential mortgage-backed securities 1,175,006 — 1,174,997 9 Commercial mortgage-backed securities 979,419 — 974,602 4,817 Collateralized loan and debt obligations 248,011 — 246,042 1,969 Asset-backed securities 413,221 — 410,228 2,993 Total fixed maturity investments $ 5,092,581 $ 105,121 $ 4,975,170 $ 12,290 Equity securities Equity investments 202,535 138,463 64,072 — Emerging market debt funds 60,150 — 60,150 — Convertible funds 46,111 — 46,111 — Preferred equity investments 15,836 — 15,836 — Short-term fixed income fund 6,736 6,736 — — Total equity securities $ 331,368 $ 145,199 $ 186,169 $ — Short-term investments 9,014 — 9,014 — Other assets (see Note 9) 99,504 — 73,889 25,615 Total assets $ 5,532,467 $ 250,320 $ 5,244,242 $ 37,905 Liabilities Other liabilities (see Note 9) $ 54,338 $ — $ 18,972 $ 35,366 Debt 623,740 — 623,740 — Total liabilities $ 678,078 $ — $ 642,712 $ 35,366 During 2014 , $13.3 million of primarily commercial and residential mortgage-backed securities and corporate securities were transferred into Level 3 as no observable inputs were available, and $7.5 million of primarily commercial and residential mortgage-backed securities and collateralized loan and debt obligations were transferred out of Level 3 as market activity for these securities increased and observable inputs became available. During the year ended December 31, 2014 , $6.6 million of U.S. government and agencies securities were transferred from Level 1 to Level 2 as they no longer qualified as on the run U.S. treasury securities. Level 3 assets represented 2.2% and 0.7% of the Company's total available for sale and trading investments and derivative instruments at December 31, 2015 and 2014 , respectively. At December 31, 2015 , Level 3 securities were primarily comprised of corporate securities and weather derivatives. At December 31, 2014 , Level 3 securities were primarily comprised of corporate securities, mortgage-backed securities, collateralized loan and debt obligations, asset-backed securities, and weather derivatives. There were no material changes in the Company's valuation techniques for the year ended December 31, 2015 . 5. Fair value measurement, cont'd. Other assets and other liabilities measured at fair value included assets of $41.5 million ( 2014 - $25.6 million ) and liabilities of $42.0 million ( 2014 - $35.4 million ) related to proprietary, non-exchange traded derivative-based risk management products used in the Company's weather risk management business, and hedging and trading activities related to these risks. In instances where market prices are not available, the Company may use industry or internally developed valuation techniques such as historical analysis and simulation modeling to determine fair value and are considered Level 3. Observable and unobservable inputs to these valuation techniques vary by contract requirements and commodity type, are validated using market-based or independently sourced parameters where applicable and may typically include the following: • Observable inputs: contract price, notional, option strike, term to expiry, interest rate, contractual limits; • Unobservable inputs: correlation; and • Both observable and unobservable: forward commodity price, forward weather curve. The Company's weather curves are determined by taking the average payouts for each transaction within its portfolio utilizing detrended historical weather measurements. The Company's commodity curves are determined using historical market data scaled to currently observed market prices. The range of each unobservable input could vary based on the specific commodity, including, but not limited to natural gas, electricity, crude, liquids, temperature or precipitation. Due to the diversity of the portfolio, the range of unobservable inputs could be wide-spread as reflected in the below table on quantitative information. If a trade has one or more significant valuation input that is unobservable, such trade is initially valued at the transaction price, which is considered to be the best initial estimate of fair value. Subsequent to the initial valuation, the Company updates market observable inputs to reflect observable market changes. The unobservable inputs are validated at each reporting period and are only changed when corroborated by evidence such as similar market transactions, third-party pricing services and/or broker or dealer quotations or other empirical market data. Changes in any or all of the unobservable inputs listed above may contribute positively or negatively to the overall portfolio fair value depending upon the underlying position. In general, movements in weather curves are the largest contributing factor that impacts fair value. Below is a summary of quantitative information regarding the significant observable and unobservable inputs used in determining the fair value of the net weather and energy related derivative liabilities classified in Level 3 that are measured at fair value on a recurring basis at December 31, 2015 and 2014 : December 31, 2015 Fair Value (Level 3) Valuation Techniques Unobservable Inputs Low High Weighted Average or Actual (U.S. dollars in thousands, except for correlation) Net weather and energy related derivative liabilities $ 526 Historical Analysis and Simulation Correlation 0 1 Actual Weather curve $ (4,000 ) $ 10,600 Actual Commodity curve $ — $ 13 Actual December 31, 2014 Fair Value (Level 3) Valuation Techniques Unobservable Inputs Low High Weighted Average or Actual (U.S. dollars in thousands, except for correlation) Net weather and energy related derivative liabilities $ 9,751 Historical Analysis and Simulation Correlation 0 1 Actual Weather curve $ (828 ) $ 2,500 Actual Commodity curve $ — $ 13 Actual 5. Fair value measurement, cont'd. The following tables present a reconciliation of the beginning and ending balances for all assets and liabilities measured at fair value on a recurring basis using Level 3 inputs during the years ended December 31, 2015 and 2014 . December 31, 2015 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of year $ 12,290 $ 25,615 $ 37,905 $ (35,366 ) Total equity income and realized and unrealized gains included in earnings 754 — 754 — Total equity losses and realized and unrealized losses included in earnings (3,539 ) — (3,539 ) — Total income included in other underwriting loss — 26,326 26,326 39,111 Total loss included in other underwriting loss — (29,277 ) (29,277 ) (34,049 ) Change in unrealized gains included in other comprehensive (loss) income 126 — 126 — Change in unrealized losses included in other comprehensive (loss) income (306 ) — (306 ) — Purchases 13 4,750 4,763 (4,231 ) Issues — 21,559 21,559 (34,114 ) Sales (15,695 ) — (15,695 ) — Settlements — (7,470 ) (7,470 ) 26,620 Transfers into Level 3 131,215 — 131,215 — Transfers out of Level 3 (12,405 ) — (12,405 ) — Level 3, end of year $ 112,453 $ 41,503 $ 153,956 $ (42,029 ) December 31, 2014 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of year $ 7,328 $ 14,038 $ 21,366 $ (19,569 ) Total equity income and realized gains included in earnings 144 — 144 — Total equity losses and losses included in earnings (85 ) — (85 ) — Total income included in other underwriting loss — 32,642 32,642 29,040 Total loss included in other underwriting loss — (27,147 ) (27,147 ) (37,617 ) Change in unrealized gains included in other comprehensive (loss) income 801 — 801 — Change in unrealized losses included in other comprehensive (loss) income (706 ) — (706 ) — Purchases 842 2,807 3,649 (1,404 ) Issues — 15,631 15,631 (23,197 ) Sales (1,848 ) — (1,848 ) (2,495 ) Settlements — (12,356 ) (12,356 ) 19,876 Transfers into Level 3 13,311 — 13,311 — Transfers out of Level 3 (7,497 ) — (7,497 ) — Level 3, end of year $ 12,290 $ 25,615 $ 37,905 $ (35,366 )

Reserve For Losses And Loss Exp

Reserve For Losses And Loss Expenses	12 Months Ended
	Dec. 31, 2015
Insurance Loss Reserves [Abstract]
Reserve For Losses And Loss Expenses	6. Reserve for losses and loss expenses Activity in the reserve for losses and loss expenses for the years ended December 31, 2015 , 2014 and 2013 is summarized as follows: 2015 2014 2013 Gross reserve for losses and loss expenses, January 1 $ 3,846,859 $ 4,002,259 $ 4,240,876 Reinsurance recoverable on unpaid losses 670,795 593,755 691,783 Net reserve for losses and loss expenses, January 1 3,176,064 3,408,504 3,549,093 Incurred related to: Current year 1,160,572 1,203,977 1,442,076 Prior years (243,464 ) (233,815 ) (222,392 ) Total incurred 917,108 970,162 1,219,684 Paid related to: Current year (265,898 ) (439,169 ) (524,010 ) Prior years (867,739 ) (719,043 ) (838,082 ) Total paid (1,133,637 ) (1,158,212 ) (1,362,092 ) Amounts acquired (1) 675,019 — — Foreign currency translation and other (32,083 ) (44,390 ) 1,819 Net reserve for losses and loss expenses, December 31 3,602,471 3,176,064 3,408,504 Reinsurance recoverable on unpaid losses 907,944 670,795 593,755 Gross reserve for losses and loss expenses, December 31 $ 4,510,415 $ 3,846,859 $ 4,002,259 (1) Represents the fair value of Montpelier's reserve for losses and loss expenses and reinsurance recoverable acquired at July 31, 2015. During 2015 , the Company's estimated ultimate losses for prior accident years were reduced by $243.5 million ( 2014 - $233.8 million ; 2013 - $222.4 million ) due to lower claims emergence than originally estimated by the Company. During 2015 , the Company experienced favorable development in the Reinsurance segment of $161.5 million across each line of business. In the Insurance segment, the Company experienced $82.0 million of favorable development across each line of business. During 2014 , the Company experienced favorable development in the Reinsurance segment of $153.2 million across each line of business. In the Insurance segment, the Company experienced $80.6 million of favorable development across each line of business. During 2013 , the Company experienced favorable development in the Reinsurance segment of $188.5 million across each line of business. In the Insurance segment, the Company experienced $33.9 million of favorable development across each line of business. Reserves for losses and loss expenses are based in part upon the estimation of losses resulting from catastrophic events. Estimation of these losses and loss expenses are based upon the Company's historical claims experience and is inherently difficult because of the Company's short operating history and the possible severity of catastrophe claims. Therefore, the Company uses both proprietary and commercially available models, as well as historical reinsurance industry catastrophe claims experience in addition to its own historical data for purposes of evaluating trends and providing an estimate of ultimate claims costs. A significant portion of the Company's contracts and policies cover excess layers for high severity exposures. Underwriting results and ultimate claims payments for this type of coverage are therefore not typically reported to the Company until later in the contract and policy lives. As a result, the level of losses reported to date is not necessarily indicative of expected future results.

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2015
Reinsurance Disclosures [Abstract]
Reinsurance	7. Reinsurance The effects of reinsurance on premiums earned and written during the years ended December 31, 2015 , 2014 and 2013 are as follows: Year Ended December 31, 2015 Year Ended December 31, 2014 Year Ended December 31, 2013 Earned Written Earned Written Earned Written Direct $ 1,938,830 $ 2,085,901 $ 1,521,648 $ 1,716,128 $ 1,472,796 $ 1,475,429 Assumed 1,331,831 1,234,960 1,132,370 1,177,948 1,139,487 1,189,815 Ceded (1,292,208 ) (1,370,391 ) (790,040 ) (959,870 ) (595,799 ) (616,311 ) $ 1,978,453 $ 1,950,470 $ 1,863,978 $ 1,934,206 $ 2,016,484 $ 2,048,933 The Company purchases reinsurance to reduce its exposure to risk of loss in certain insurance and reinsurance lines of business. Reinsurance recoverables are recorded as assets if the reinsurer is deemed able to meet its obligations. Ceded reinsurance contracts do not relieve the Company from its obligations to policyholders. The Company remains primarily liable to its policyholders for the portion reinsured to the extent that any reinsurer does not meet the obligations assumed under the reinsurance agreements. During the year ended December 31, 2015 , the Company recorded ceded losses of $833.7 million ( 2014 - $ 575.7 million; 2013 - $ 683.2 million). The balance of reinsurance recoverable on paid and unpaid losses at December 31, 2015 and 2014 was distributed as follows based on the ratings of the reinsurers: Rating December 31, 2015 December 31, 2014 U.S. Government sponsored program $ 234,596 $ 339,617 A+ and above 458,255 294,216 A 476,184 248,297 A- 7,060 4 Not rated 19,875 6,952 Total $ 1,195,970 $ 889,086 At December 31, 2015 and 2014 , the Company held collateral of $ 321.5 million and $ 199.7 million, respectively, related to its ceded reinsurance agreements.

Debt And Financing Arrangements

Debt And Financing Arrangements	12 Months Ended
	Dec. 31, 2015
Debt Instruments [Abstract]
Debt And Financing Arrangements	8. Debt and financing arrangements Credit Facility On April 19, 2012, the Company and certain designated subsidiaries of the Company entered into a $700.0 million four -year revolving credit facility with JPMorgan Chase Bank, N.A. ("JPMorgan") as administrative agent (the "Credit Facility"). Upon entering into the Credit Facility, the Company terminated its existing $1,175.0 million amended and restated credit agreement dated May 8, 2007 with JPMorgan as administrative agent. As of December 31, 2015 and 2014 , there were no borrowings under the Credit Facility and letters of credit outstanding under the Credit Facility were $329.9 million and $204.0 million , respectively. The Credit Facility consists of two tranches: (i) tranche 1 collateralized credit facility in an aggregate principal amount of $560.0 million (the "Tranche 1 Facility"), which is collateralized on a several basis by the respective entity incurring such obligation by cash and securities deposited into collateral accounts from time to time with Deutsche Bank Trust Company Americas and (ii) tranche 2 facility, which is not collateralized, in an aggregate principal amount of $140.0 million (the "Tranche 2 Facility"). The proceeds of the Credit Facility may be used for general corporate purposes, to finance potential acquisitions and for the repurchase of the Company's outstanding publicly or privately issued securities. So long as the Company is not in default under the terms of the Credit Facility, the Company may request that the size of the Credit Facility be increased by $350.0 million , provided that no participating lender is obligated to increase its commitments under the Credit Facility. 8. Debt and financing arrangements, cont'd. For letters of credit issued on a collateralized basis under the Tranche 1 Facility, the Company is required to pay a fee of 0.45% on the daily stated amount of such letters of credit. For letters of credit issued on an uncollateralized basis under the Tranche 2 Facility, the Company is required to pay a fee ranging from 1.125% to 1.750% over LIBOR on the daily stated amount of such letters of credit based upon the Company's debt ratings as issued by Moody's or S&P. The interest rate for revolving loans under the Tranche 2 Facility is (a) the highest of (i) 0.5% in excess of the federal funds effective rate, (ii) the prime rate as announced by JP Morgan, and (iii) the Eurodollar rate applicable for an interest period of one month plus 1% , plus a margin ranging from 0.125% to 0.750% depending upon the type of loan and the Company's ratings as issued by Moody's and S&P, or (b) LIBOR plus a margin ranging from 1.125% to 1.750% . In addition, the Credit Facility required the Company to pay to the lenders a commitment fee. The Credit Facility requires the Company's compliance with certain customary restrictive covenants. These include certain financial covenants, such as maintaining a leverage ratio (no greater than 0.35 :1.00 at any time) and a consolidated tangible net worth (no less than $1.8 billion at any time). In addition, each of the Company's regulated insurance subsidiaries that has a claims paying rating from A.M. Best must maintain a rating of at least B++ at all times. The terms of the Credit Facility restrict the declaration or payment of dividends if the Company is already in default or the payment or declaration would cause a default under the terms of the Credit Facility. The Credit Facility also contains customary event of default provisions, including failure to pay principal or interest under the Credit Facility, insolvency of the Company, a change in control of the Company, a breach of the Company's representations or covenants in the Credit Facility or a default by the Company under its other indebtedness. Upon the occurrence of an event of default under the Credit Facility, the lenders can terminate their commitments under the Credit Facility, require repayment of any outstanding revolving loans, give notice of termination of any outstanding letters of credit in accordance with their terms, require the delivery of cash collateral for outstanding letters of credit and foreclose on any security held by the lenders under the Credit Facility. On June 25, 2014, the Company entered into the First Amendment (the "Amendment") to the Credit Facility. The Amendment also amends the Security Agreement, dated as of April 19, 2012 (the "Security Agreement"), among the Company and various designated subsidiaries of the Company, Deutsche Bank Trust Company America, as collateral agent, and JPMorgan. The Amendment contained certain administrative amendments to the Credit Facility and the Security Agreement as well as certain amendments applicable to the proposed acquisition of Aspen Insurance Holdings Limited. Uncommitted Letter of Credit Agreements The Company is party to certain uncommitted letter of credit reimbursement agreements ("LOC Agreements") that allow for the issuance of letters of credit in a variety of currencies, including U.S. dollars. The fees paid under the LOC Agreements depend on the amount of the outstanding letters of credit and vary from 0.30% to 0.45% on the principal amount of letters of credit outstanding to a fee negotiated at the time of issuance of the individual letters of credit. The total amount of letters of credit outstanding under the LOC Agreements at December 31, 2015 was $11.7 million ( December 31, 2014 - $5.9 million ). 7% Senior Notes The Company has issued $335.0 million principal amount of 7% Senior Notes due July 15, 2034 (the "7% Senior Notes"). The 7% Senior Notes are senior unsecured obligations of Endurance Holdings and rank equally with all of Endurance Holdings' existing and future unsecured and unsubordinated debt. The 7% Senior Notes are also effectively junior to claims of creditors of Endurance Holdings' subsidiaries, including policyholders, trade creditors, debt holders, and taxing authorities. The indentures governing the 7% Senior Notes contain customary covenants and events of default for senior unsecured indebtedness, including events of default for non-payment of principal or interest, breaches of covenants, insolvency of the Company or a default by the Company under other outstanding indebtedness. The Company was in compliance with all covenants contained within the indentures governing the 7% Senior Notes as of December 31, 2015 . 6.15% Senior Notes The Company issued $200.0 million principal amount of 6.15% Senior Notes due 2015 (the "6.15% Senior Notes"). The 6.15% Senior Notes were senior unsecured obligations of Endurance Holdings and ranked equally with all of Endurance Holdings' existing and future unsecured and unsubordinated debt. The 6.15% Senior Notes also were effectively junior to claims of creditors of Endurance Holdings' subsidiaries, including policyholders, trade creditors, debt holders, and taxing authorities. The 6.15% Senior Notes matured on October 15, 2015 and were repaid by the Company on that date. 8. Debt and financing arrangements, cont'd. 4.7% Senior Notes Upon closing of the acquisition of Montpelier, Montpelier, as issuer, Endurance Holdings, as parent guarantor, and The Bank of New York Mellon, as trustee, entered into a Fourth Supplemental Indenture, dated as of July 31, 2015 (the "Fourth Supplemental Indenture"). The Fourth Supplemental Indenture amended the Indenture, dated as of July 15, 2003 (as amended and supplemented from time to time (collectively, the "Senior Notes Supplemental Indentures")) applicable to the 4.7% Senior Unsecured Notes Due 2022 (the "4.7% Senior Notes") originally issued by Montpelier on October 2, 2012 in an aggregate principal amount of $300.0 million . The Senior Notes Supplemental Indentures provided for the unconditional assumption of the due and punctual payment of the principal of, any premium and interest on and any additional amounts with respect to the 4.7% Senior Notes and the performance of every obligation in the Senior Notes Indenture and the 4.7% Senior Notes to be performed or observed. The 4.7% Senior Notes bear a rate of interest equal to 4.7% per annum, payable semi-annually in arrears on April 15 and October 15 each year. The 4.7% Senior Notes mature on October 15, 2022. The 4.7% Senior Notes do not contain any covenants regarding financial ratios or specified levels of net worth or liquidity to which the Company or any of its subsidiaries must adhere but do contain customary covenants and events of default for senior unsecured indebtedness, including events of default for non-payment of principal or interest, breaches of covenants, insolvency of the Company or a default by the Company under other outstanding indebtedness. The Company was in compliance with all covenants contained within the indentures governing the 4.7% Senior Notes as of December 31, 2015 . The 4.7% Senior Notes are senior unsecured obligations of Endurance Holdings and rank equally with all of Endurance Holdings' existing and future unsecured and unsubordinated debt. The 4.7% Senior Notes are also effectively junior to claims of creditors of Endurance Holdings' subsidiaries, including policyholders, trade creditors, debt holders, and taxing authorities. Trust Preferred Securities Upon closing the acquisition of Montpelier, Montpelier, as issuer, Endurance Holdings, as parent guarantor, and Wilmington Trust Company, as trustee, entered into the Second Supplemental Indenture, dated as of July 31, 2015 (the "Second Supplemental Indenture"). The Second Supplemental Indenture amended the Junior Subordinated Indenture, dated as of January 6, 2006 (as amended and supplemented from time to time (collectively, the "Junior Subordinated Supplemental Indentures")). The Junior Subordinated Supplemental Indentures provided for the express assumption by Endurance Holdings of the due and punctual payment of the principal of and any premium and interest (including any additional interest) on all of the Trust Preferred Securities and the performance of every covenant of the Junior Subordinated Indenture on the part of Montpelier to be performed or observed. Montpelier originally issued the Trust Preferred Securities in January 2006 in an aggregate principal amount of $100.0 million . The Trust Preferred Securities mature on March 30, 2036 and bear interest at a floating rate of 3-month LIBOR plus 380 basis points, reset quarterly. The Trust Preferred Securities may be redeemed at the option of the issuer prior to maturity at a redemption price equal to 100% of the principal amount thereof plus accrued interest, provided that the issuer has received the prior approval of any applicable insurance regulatory authority with respect to such redemption, if required. The Trust Preferred Securities do not contain any covenants regarding financial ratios or specified levels of net worth or liquidity to which the Company or any of its subsidiaries must adhere. LIBOR Swap Upon closing of the acquisition of Montpelier, the Company became a party to the LIBOR Swap, which will result in the future net cash flows in connection with the Trust Preferred Securities for the 5 -year period beginning March 30, 2012 being the same as if these securities bore interest at a fixed rate of 4.905% , provided the Company holds the LIBOR Swap to its maturity. Net realized and unrealized gains and losses associated with the LIBOR Swap are reported within net realized and unrealized gains on the Company's Consolidated Statements of Income and Comprehensive Income, as opposed to interest expense. Interest Payments The Company made aggregate interest payments of $40.5 million during the year ended December 31, 2015 ( 2014 - $40.4 million ; 2013 - $35.7 million ). 8. Debt and financing arrangements, cont'd. BCRH Credit Agreement Upon closing of the acquisition of Montpelier on July 31, 2015, the Company became a guarantor of the BCRH 364-day unsecured credit agreement (the "BCRH Credit Agreement"), which permits BCRH to borrow up to $20.0 million on a revolving basis for working capital and general corporate purposes. The Company is entitled to receive an annual guarantee fee from BCRH equal to 0.125% of the facility's total capacity. As of December 31, 2015 , BCRH had $13.0 million outstanding borrowings under the BCRH Credit Agreement. With respect to BCRH's outstanding borrowings at December 31, 2015 , $4.0 million was repaid on February 2, 2016 and was subject to an annual interest rate of 1.33% , $5.0 million was repaid February 22, 2016 and was subject to an annual interest rate of 1.48% , and $4.0 million must be repaid or extended, in the form of a new borrowing, no later than March 11, 2016 and is subject to an annual interest rate of 1.51% . The BCRH Credit Agreement contains covenants that limit BCRH's ability to, among other things, grant liens on its assets, sell assets, merge or consolidate, incur debt and enter into certain transactions with affiliates. The BCRH Credit Agreement also contains covenants that require BCRH to maintain a debt to total capitalization ratio less than or equal to 22.5% and to maintain at least 70% of its total shareholders' equity as of the date of the BCRH Credit Agreement. In addition, an uncured default by the Company of the covenants contained in the Credit Facility would result in a default under the BCRH Credit Agreement. If BCRH or the Company were to fail to comply with any of the applicable covenants, the lender could revoke the facility and exercise remedies against BCRH or the Company. The Company was in compliance with all covenants applicable to the Company in the BCRH Credit Agreement as of December 31, 2015 . BCGR Credit Agreement Upon closing of the acquisition of Montpelier on July 31, 2015, the Company became a guarantor of the BCGR 364-day unsecured credit agreement (the "BCGR Credit Agreement"), which permits BCGR to borrow up to $20.0 million on a revolving basis for working capital and general corporate purposes. The Company is entitled to receive an annual guarantee fee from BCGR equal to 0.125% of the facility's total capacity. As of December 31, 2015 , BCGR had $6.0 million of outstanding borrowings under the BCGR Credit Agreement. With respect to BCGR's outstanding borrowings at December 31, 2015 , $3.0 million was repaid on February 1, 2016 and was subject to an annual interest rate of 1.54% , and $3.0 million was repaid February 12, 2016 and was subject to an annual interest rate of 1.51% . The BCGR Credit Agreement contains covenants that limit BCGR's ability, among other things, to grant liens on its assets, sell assets, merge or consolidate, incur debt and enter into certain transactions with affiliates. In addition, an uncured default by the Company of the covenants contained in the Credit Facility would result in a default under the BCGR Credit Agreement. If BCGR or the Company were to fail to comply with any of the applicable covenants, the lender could revoke the facility and exercise remedies against BCGR or the Company. The Company was in compliance with all covenants applicable to the Company in the BCGR Credit Agreement as of December 31, 2015 .

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	9. Derivatives In 2004, prior to the issuance of the 7% Senior Notes, the Company entered into an interest rate lock on a notional amount of $125.0 million to protect against interest rate increases before the anticipated issuance of the Senior Notes. The objective of the interest rate lock was to protect 50% of the forecasted receipt of proceeds from the issuance of the 7% Senior Notes offering, which was subject to change prior to issuance due to fluctuations in the benchmark 30 year U. S. Treasury rate. Upon issuance of the 7% Senior Notes, the interest rate lock was settled through payment by the Company of $2.7 million . The interest rate lock agreement was designated as a "cash flow hedge" under current accounting guidance and accordingly, the fair value of the derivative was recorded in other comprehensive income and is being recognized as a component of interest expense in the Consolidated Statements of Income and Comprehensive Income as the interest expense related to the 7% Senior Notes affects earnings. The net income effect of the interest rate lock was not material. 9. Derivatives, cont'd. The Company regularly transacts in certain derivative-based weather risk management products primarily to address weather and energy risks on behalf of third parties. The markets for these derivatives are generally linked to energy and agriculture commodities, weather and other natural phenomena. Generally, the Company's current portfolio of such derivative contracts is of short duration and such contracts are predominantly seasonal in nature. The Company also invests a portion of its investments with third party investment managers with investment guidelines that permit the use of derivative instruments. The Company may enter derivative transactions directly or as part of strategies employed by its external investment managers. None of the Company's derivatives are designated as hedges under current accounting guidance, with the exception of the interest rate lock. The Company's objectives for holding these derivatives are as follows: Interest Rate Futures, Swaps, Swaptions and Options - to manage exposure to interest rate risk, which can include increasing or decreasing its exposure to this risk through modification of the portfolio composition and duration. Industry Loss Warranty ("ILW") Swaps - to manage underwriting risk. The Company has entered into ILW swap contracts which provide reinsurance-like protection to the Company for specific loss events associated with certain lines of its business. The Company has also sold ILW protection, which provides reinsurance-like protection to third parties for specific loss events. Foreign Exchange Forwards, Futures and Options - as part of its overall currency risk management and investment strategies. Credit Default Swaps - to manage market exposures. The Company may assume or economically hedge credit risk through credit default swaps to replicate or hedge investment positions. The original term of these credit default swaps is generally five years or less. To-Be-Announced Mortgage-backed Securities (“TBAs”) - to enhance investment performance and as part of the overall investment strategy. TBAs represent commitments to purchase or sell a future issuance of agency mortgage-backed securities. For the period between the purchase of a TBA and issuance of the underlying securities, the Company’s position is accounted for as a derivative. Energy and Weather Contracts - to address weather and energy risks. The Company may purchase or sell contracts with financial settlements based on the performance of an index linked to a quantifiable weather element, such as temperature, precipitation, snowfall or windspeed, and structures with multiple risk triggers indexed to a quantifiable weather element and a weather sensitive commodity price, such as temperature and electrical power or natural gas. Generally, the Company’s current portfolio of energy and weather derivative contracts is of comparably short duration and such contracts are predominantly seasonal in nature. LIBOR Swap – to establish future net cash flows in connection with the Trust Preferred Securities for the 5 -year period beginning March 30, 2012 as if these securities bore interest at a fixed rate of 4.905% . See Note 8, Debt and financing arrangements. Loss Development Cover – as part of the sale of Montpelier U.S. Insurance Company ("MUSIC") to Selective Insurance Group, Inc. ("Selective"), Montpelier Reinsurance Ltd. ("Montpelier Re", now Endurance Bermuda) entered into a loss development cover with MUSIC which ensures that MUSIC's reserve for losses and loss expenses relating to retained business written on or prior to December 31, 2011 remains adequate. Under the loss development cover, any future adverse development associated with such retained reserves will be protected by Endurance Bermuda and any future favorable development associated with such retained reserves will benefit Endurance Bermuda. 9. Derivatives, cont'd. The fair values and the related notional values of derivatives at December 31, 2015 and 2014 are noted below. December 31, 2015 December 31, 2014 Fair Value Notional Principal Amount Fair Value Notional Principal Amount Derivatives recorded in other assets Foreign exchange forward contracts $ 425 $ 38,818 $ 651 $ 42,694 Credit default swaps 36 4,225 — — Interest rate futures — — 7 7,595 TBAs 26,924 25,700 73,231 70,000 Energy and weather contracts 41,507 70,388 25,615 81,624 Total recorded in other assets $ 68,892 $ 99,504 Derivatives recorded in other liabilities Foreign exchange forward contracts $ 372 $ 30,400 $ 123 $ 20,945 Credit default swaps 276 7,800 — — Interest rate swaps 7 42,000 20 12,549 Interest rate swaptions — — 9 13,100 Interest rate futures 8 54,488 — — ILWs 259 19,500 — — LIBOR swap 233 100,000 — — TBAs — — 18,820 18,000 Loss development cover 2,904 22,322 — — Energy and weather contracts 42,029 148,325 35,366 135,050 Total recorded in other liabilities $ 46,088 $ 54,338 Net derivative asset $ 22,804 $ 45,166 At December 31, 2015 , derivative assets of $68.9 million (December 31, 2014 - $99.5 million ) and liabilities of $46.1 million (December 31, 2014 - $54.3 million ) were subject to master netting agreements, which provide for the ability to settle the derivative asset and liability with each counterparty on a net basis. Interest rate futures are not subject to master netting agreements. At December 31, 2015 and 2014 , the Company's derivative instruments were recorded on a gross basis in the Consolidated Balance Sheets. At December 31, 2015 , the Company held $30.0 million ( December 31, 2014 - nil ) of reverse repurchase agreements. These loans are fully collateralized, are generally outstanding for a short period of time and are presented as part of cash and cash equivalents in the Consolidated Balance Sheets. The required collateral for these loans is either cash or U.S. treasury securities at a minimum rate of 102% of the loan principal. Upon maturity, the Company receives principal and interest income. 9. Derivatives, cont'd. The gains and losses on the Consolidated Statements of Income and Comprehensive Income for derivatives for the years ended December 31, 2015 , 2014 and 2013 were as follows: 2015 2014 2013 Total gain included in net foreign exchange losses from foreign exchange forward contracts $ 2,095 $ 1,880 $ 357 Interest rate futures 79 121 44 Credit default swaps (50 ) 30 49 Interest rate swaps (915 ) (4,239 ) 1,241 Interest rate swaptions 56 477 291 ILWs (326 ) — — LIBOR swap 332 — — TBAs 496 3,938 (958 ) Total (losses) gains included in net realized and unrealized gains (328 ) 327 667 Energy and weather contracts 2,281 (315 ) (261 ) Loss development cover (1,419 ) — — Total gain (loss) included in other underwriting loss 862 (315 ) (261 ) Total gains from derivatives $ 2,629 $ 1,892 $ 763

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment Reporting	10. Segment reporting The determination of the Company's business segments is based on how the Company monitors the performance of its underwriting operations. The Company has two reportable business segments, Insurance and Reinsurance. • Insurance – This segment is comprised of four lines of business: agriculture, casualty and other specialty, professional lines, and property, marine/energy and aviation. The agriculture line of business is comprised of multi-peril crop insurance, crop hail, livestock risk protection and other agriculture risk management products. The casualty and other specialty line of business is comprised of the insurance and facultative reinsurance of third party liability exposures, including casualty and healthcare liability. The professional line of business includes directors' and officers' liability, errors and omissions, employment practices liability, environmental liability and pension trust liability insurance. The property, marine/energy and aviation line of business is comprised of the insurance and facultative reinsurance of commercial properties, inland marine and ocean marine insurance, energy insurance, and general liability and property coverages for a wide range of general aviation risks. • Reinsurance – This segment is comprised of five lines of business: catastrophe, property, casualty, professional lines, and specialty. The catastrophe line of business includes reinsurance for catastrophic perils on a treaty basis. The property line of business includes proportional and excess of loss reinsurance of personal and commercial exposures. The casualty line of business is comprised of third party liability exposures, clash and workers' compensation coverages. The professional line of business includes directors' and officers' liability, errors and omissions, employment practices liability, environmental liability and pension trust liability reinsurance. The specialty line of business includes the reinsurance of aviation and space business and proportional and non-proportional reinsurance of hull and cargo insurance business, and proportional and excess of loss coverages of contract and commercial surety business, personal accident coverages, political risk coverages, weather risk management products and agriculture coverages for weather related perils as well as protection from yield and price risks. 10. Segment reporting, cont'd. Management measures Insurance and Reinsurance segment results on the basis of the combined ratio, which is obtained by dividing the sum of the net losses and loss expenses, acquisition expenses and general and administrative expenses by net premiums earned. When purchased within a single line of business, ceded reinsurance and recoveries are accounted for within that line of business. When purchased across multiple lines of business, ceded reinsurance and recoveries are allocated to the lines of business in proportion to the related risks assumed. The Company does not manage its assets by segment; accordingly, investment income and total assets are not allocated to the individual business segments. General and administrative expenses incurred by segments are allocated directly. Remaining general and administrative expenses not incurred by the segments are classified as corporate expenses and are not allocated to the individual business segments. Ceded reinsurance and recoveries are recorded within the business segment to which they apply. The underwriting results of Montpelier are included in the Company's segment results from August 1, 2015. The following table provides a summary of the segment revenues and results for the year ended December 31, 2015 , reserve for losses and loss expenses as of December 31, 2015 and the carrying value of goodwill as of December 31, 2015 : Insurance Reinsurance Total Revenues Gross premiums written $ 2,085,901 $ 1,234,960 $ 3,320,861 Ceded premiums written (1,205,528 ) (164,863 ) (1,370,391 ) Net premiums written 880,373 1,070,097 1,950,470 Net premiums earned 824,552 1,153,901 1,978,453 Other underwriting loss — (3,694 ) (3,694 ) 824,552 1,150,207 1,974,759 Expenses Net losses and loss expenses 503,561 413,547 917,108 Acquisition expenses 80,252 267,633 347,885 General and administrative expenses 140,012 119,779 259,791 723,825 800,959 1,524,784 Underwriting income $ 100,727 $ 349,248 449,975 Net investment income 113,826 Corporate expenses (114,429 ) Net foreign exchange losses (26,964 ) Net realized and unrealized gains 12,660 Net impairment losses recognized in earnings (3,715 ) Amortization of intangibles (30,620 ) Interest expense (41,260 ) Income before income taxes $ 359,473 Net loss ratio 61.1 % 35.8 % 46.4 % Acquisition expense ratio 9.7 % 23.2 % 17.6 % General and administrative expense ratio 17.0 % 10.4 % 18.9 % (1) Combined ratio 87.8 % 69.4 % 82.9 % Reserve for losses and loss expenses $ 2,507,361 $ 2,003,054 $ 4,510,415 Goodwill $ 84,525 $ 91,930 $ 176,455 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. 10. Segment reporting, cont'd. The following table provides a summary of the segment revenues and results for the year ended December 31, 2014 , reserve for losses and loss expenses as of December 31, 2014 and the carrying value of goodwill as of December 31, 2014 : Insurance Reinsurance Total Revenues Gross premiums written $ 1,716,128 $ 1,177,948 $ 2,894,076 Ceded premiums written (855,722 ) (104,148 ) (959,870 ) Net premiums written 860,406 1,073,800 1,934,206 Net premiums earned 833,912 1,030,066 1,863,978 Other underwriting loss — (5,786 ) (5,786 ) 833,912 1,024,280 1,858,192 Expenses Net losses and loss expenses 594,561 375,601 970,162 Acquisition expenses 65,368 254,145 319,513 General and administrative expenses 148,475 98,912 247,387 808,404 728,658 1,537,062 Underwriting income $ 25,508 $ 295,622 321,130 Net investment income 131,543 Corporate expenses (66,200 ) Net foreign exchange losses (3,839 ) Net realized and unrealized gains 14,283 Net impairment losses recognized in earnings (625 ) Amortization of intangibles (6,484 ) Interest expense (40,968 ) Income before income taxes $ 348,840 Net loss ratio 71.4 % 36.4 % 52.1 % Acquisition expense ratio 7.8 % 24.7 % 17.1 % General and administrative expense ratio 17.7 % 9.6 % 16.8 % (1) Combined ratio 96.9 % 70.7 % 86.0 % Reserve for losses and loss expenses $ 2,123,772 $ 1,723,087 $ 3,846,859 Goodwill $ 47,925 $ 43,313 $ 91,238 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. 10. Segment reporting, cont'd. The following table provides a summary of the segment revenues and results for the year ended December 31, 2013 , reserve for losses and loss expenses as of December 31, 2013 and the carrying value of goodwill as of December 31, 2013 : Insurance Reinsurance Total Revenues Gross premiums written $ 1,475,429 $ 1,189,815 $ 2,665,244 Ceded premiums written (542,919 ) (73,392 ) (616,311 ) Net premiums written 932,510 1,116,423 2,048,933 Net premiums earned 946,474 1,070,010 2,016,484 Other underwriting loss — (2,046 ) (2,046 ) 946,474 1,067,964 2,014,438 Expenses Net losses and loss expenses 774,425 445,259 1,219,684 Acquisition expenses 64,778 239,652 304,430 General and administrative expenses 136,588 100,285 236,873 975,791 785,196 1,760,987 Underwriting (loss) income $ (29,317 ) $ 282,768 253,451 Net investment income 166,216 Corporate expenses (58,033 ) Net foreign exchange losses (14,214 ) Net realized and unrealized gains 15,164 Net impairment losses recognized in earnings (1,616 ) Amortization of intangibles (7,012 ) Interest expense (36,188 ) Income before income taxes $ 317,768 Net loss ratio 81.8 % 41.6 % 60.5 % Acquisition expense ratio 6.8 % 22.4 % 15.1 % General and administrative expense ratio 14.5 % 9.4 % 14.6 % (1) Combined ratio 103.1 % 73.4 % 90.2 % Reserve for losses and loss expenses $ 2,158,890 $ 1,843,369 $ 4,002,259 Goodwill $ 47,925 $ 43,368 $ 91,293 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. 10. Segment reporting, cont'd. The following table provides gross premiums written by line of business for the years ended December 31, 2015 , 2014 and 2013 : Business Segment 2015 2014 2013 Insurance Agriculture $ 840,445 $ 866,025 $ 954,389 Casualty and other specialty 514,203 396,113 303,803 Professional lines 344,482 263,538 148,537 Property, marine/energy and aviation 386,771 190,452 68,700 Total Insurance 2,085,901 1,716,128 1,475,429 Reinsurance Catastrophe 311,914 343,213 355,751 Property 209,392 287,326 297,806 Casualty 176,506 159,533 241,358 Professional lines 248,610 174,656 163,594 Specialty 288,538 213,220 131,306 Total Reinsurance 1,234,960 1,177,948 1,189,815 Total $ 3,320,861 $ 2,894,076 $ 2,665,244 The following table provides the geographic distribution of gross premiums written for the years ended December 31, 2015 , 2014 and 2013 : 2015 2014 2013 United States $ 2,305,301 $ 2,054,431 $ 1,960,693 Worldwide 566,664 456,078 435,655 Europe 209,729 172,077 153,516 Asia 75,165 38,442 23,349 Japan 58,524 45,618 33,879 Australasia 41,309 61,994 25,191 Other 64,169 65,436 32,961 Total $ 3,320,861 $ 2,894,076 $ 2,665,244 The Company attributes gross premiums written to the geographic region in which the risks originate.

Goodwill And Intangible Assets

Goodwill And Intangible Assets	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill And Intangible Assets	11. Goodwill and intangible assets The following table shows an analysis of goodwill and intangible assets for the years ended December 31, 2015 and 2014 : Goodwill Intangible assets with indefinite lives Intangible assets with finite lives Total Net balance at December 31, 2013 $ 91,293 $ 17,229 $ 56,856 $ 165,378 Additions (55 ) — 16 (39 ) Amortization — — (6,484 ) (6,484 ) Impairment loss — (5,450 ) — $ (5,450 ) Net balance at December 31, 2014 $ 91,238 $ 11,779 $ 50,388 $ 153,405 Additions (1) 87,367 57,600 293,218 438,185 Amortization — — (30,620 ) (30,620 ) Foreign currency translation (2,150 ) — (4,860 ) (7,010 ) Net balance at December 31, 2015 $ 176,455 $ 69,379 $ 308,126 $ 553,960 Gross balance $ 178,605 $ 74,829 $ 431,260 $ 684,694 Accumulated amortization — — (118,274 ) (118,274 ) Accumulated impairment losses — (5,450 ) — (5,450 ) Accumulated foreign currency translation (2,150 ) — (4,860 ) (7,010 ) Net balance $ 176,455 $ 69,379 $ 308,126 $ 553,960 (1) For additional information on the intangible assets acquired during 2015, see Note 3, Acquisition of Montpelier. For the year ended December 31, 2015 , a valuation analysis was performed to determine the fair value of the Company's intangible assets with indefinite lives which showed that none of the Company's intangible assets were impaired. For the year ended December 31, 2014, certain of the Company's U.S. insurance licenses, which are included in the Company's Insurance segment, were determined to be impaired and an impairment of $5.5 million was recognized in net realized and unrealized gains line item in the Consolidated Statements of Income and Comprehensive Income for the year ended December 31, 2014. The determination of this impairment was a result of an evaluation of recent sales prices for companies with similar insurance licenses, which indicated that the prices for excess and surplus lines licenses are lower due to the passage of Dodd-Frank legislation that has standardized and simplified the process to obtain excess and surplus lines licenses, resulting in a lower value for these licenses. During the fourth quarter of 2015, the Company voluntarily changed the date of its annual goodwill and indefinite-lived intangible asset impairment testing date from December 31st to October 1st. This voluntary change does not represent a material change to the Company's method of applying current accounting guidance and is preferable as it better aligns with the Company's strategic planning and forecasting process. This change will not delay, accelerate or avoid any impairment charge. This change was not applied retrospectively as it is impracticable to do so, as retrospective application would require the application of significant estimates and assumptions. It would be difficult to avoid applying hindsight and objectively determine assumptions. Therefore, the change was applied prospectively. No impairment of the Company's goodwill asset was noted following the annual impairment reviews during the years ended December 31, 2015 and 2014 . The Company expects the amortization of the intangible assets with finite lives to approximate $85.5 million in 2016 , $64.4 million in 2017 , $38.0 million in 2018, $27.7 million in 2019 , $22.9 million in 2020 and $74.5 million in all years thereafter.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	12. Commitments and contingencies Concentrations of credit risk. The areas where significant concentrations of credit risk may exist include reinsurance recoverables, investments and cash and cash equivalents. The Company's reinsurance recoverables on paid and unpaid losses at December 31, 2015 and 2014 amounted to $1,196.0 million and $889.1 million , respectively, and resulted from reinsurance arrangements entered into in the normal course of operations. A credit exposure exists with respect to reinsurance recoverables as they may become uncollectible. The Company manages its credit risk in its reinsurance relationships by transacting with reinsurers that it considers financially sound and, if necessary, the Company may hold collateral in the form of cash, trust accounts and/or irrevocable letters of credit. This collateral can be drawn on for amounts that remain unpaid beyond specified time periods on an individual reinsurer basis. As of December 31, 2015 , $941.5 million of reinsurance recoverable on paid and 12. Commitments and contingencies, cont'd. unpaid losses ( 2014 - $542.5 million ) was due from reinsurers rated A- or better by A.M. Best or S&P. An additional $234.6 million ( 2014 - $339.6 million ) of reinsurance recoverable on paid and unpaid losses was due from a U.S. government sponsored reinsurance program as of December 31, 2015 . At December 31, 2015 and 2014 , the Company held collateral of $321.5 million and $199.7 million , respectively, related to its ceded reinsurance agreements. As of December 31, 2015 , substantially all the Company's cash and investments were held by six custodians. The Company's investment guidelines limit the amount of credit exposure to any one issuer other than the U.S. Treasury and certain other foreign government obligations rated AAA. Major production sources. The following table shows the percentage of gross premiums written generated through the Company's largest brokers for the years ended December 31, 2015 , 2014 and 2013 : Broker 2015 2014 2013 Marsh & McLennan Companies, Inc. 19.8 % 19.1 % 17.3 % Aon Benfield 12.8 % 13.2 % 15.6 % Willis Companies 9.2 % 10.6 % 9.9 % Total of largest brokers 41.8 % 42.9 % 42.8 % Letters of credit. As of December 31, 2015 , the Company had issued letters of credit of $341.6 million ( 2014 - $209.9 million ) under its credit facilities and letter of credit reimbursement agreements in favor of certain ceding companies to collateralize obligations. Investment commitments. As of December 31, 2015 and 2014 , the Company had pledged cash and cash equivalents and fixed maturity investments of $108.9 million and $130.6 million , respectively, in favor of certain ceding companies to collateralize obligations. As of December 31, 2015 and 2014 , the Company had also pledged $383.3 million and $240.0 million of its cash and fixed maturity investments as required to meet collateral obligations for $341.6 million and $209.9 million in secured letters of credit outstanding under its credit facilities, respectively. In addition, at December 31, 2015 and 2014 , cash and fixed maturity investments with fair values of $208.3 million and $205.2 million were on deposit with U.S. state regulators, respectively. The Company is subject to certain commitments with respect to other investments at December 31, 2015 and 2014 . See Note 4, Investments. Investment assets held in trust. Blue Water Re and Blue Water Re II do not operate with a financial strength rating and, instead, fully collateralizes their reinsurance obligations through cash and cash equivalents held in trust funds established by Blue Water Re and Blue Water Re II (the "Blue Water Trusts") for the benefit of ceding companies. As of December 31, 2015 , the fair value of assets held in the Blue Water Trusts was $438.9 million , which met the minimum values required on that date. As of December 31, 2015 , Blue Capital Re had pledged $195.3 million of its cash and cash equivalents to trust accounts established for the benefit of Blue Water Re. Blue Capital Re ILS fully collateralizes its insurance-linked security obligations through cash and cash equivalents held in trust funds established by Blue Capital Re ILS (the "Blue Capital Re ILS Trusts") for the benefit of third parties. As of December 31, 2015 , the fair value of assets held in the Blue Capital Re ILS Trusts was $5.2 million , which met the minimum value required on that date. During 2015, Endurance Bermuda established a multi-beneficiary reinsurance trust (the "Endurance Reinsurance Trust") domiciled in Delaware. The Endurance Reinsurance Trust was established as a means of providing statutory credit to Endurance Bermuda's U.S. cedants. As of December 31, 2015 , the fair value of the assets held in the Endurance Reinsurance Trust exceeded $94.1 million , the minimum value required on that date. Endurance Bermuda is also party to a multi-beneficiary reinsurance trust originally established by Montpelier Re (the "Reduced Collateral Trust") domiciled in Delaware. The Reduced Collateral Trust was established as a means of providing statutory credit to Endurance Bermuda's U.S. cedants in connection with a reduction in collateral requirements in certain states. As of December 31, 2015 , the fair value of the assets held in the Reduced Collateral Trust exceeded $10.8 million , the minimum value required on that date. 12. Commitments and contingencies, cont'd. Endurance Bermuda is party to a reinsurance trust (the "MUSIC Trust"). The MUSIC Trust was established as a means of providing statutory credit to MUSIC in support of the business retained in connection with the 2011 sale by Montpelier of MUSIC to Selective. As of December 31, 2015 , the fair value of the assets held in the MUSIC Trust exceeded $21.3 million , the minimum value required on that date. Endurance Bermuda is party to a multi-beneficiary Reinsurance Trust originally established by Montpelier Re (the "Montpelier Reinsurance Trust") domiciled in New York. The Montpelier Reinsurance Trust was established as a means of providing statutory credit to Montpelier Re's U.S. cedants. Endurance Bermuda is also party to a multi-beneficiary reinsurance trust originally established by Montpelier Re (the "FL Trust") in connection with a reduction in its Florida collateral requirements. With the consent of the New York Department of Financial Services, all assets in excess of the statutory minimum required amounts in the Montpelier Reinsurance Trust and the FL Trust were transferred to the Endurance Reinsurance Trust upon the merger of Montpelier Re with and into Endurance Bermuda, with Endurance Bermuda as the surviving entity, on December 29, 2015. As of December 31, 2015 , the fair value of assets held in the Montpelier Reinsurance Trust was $20.0 million and the fair value of assets held in the FL Trust was $10.0 million , both of which exceeded the minimum values required on that date. The Company is party to a Lloyd's Deposit Trust Deed (the "Lloyd's Capital Trust") in order to meet Endurance Corporate Capital Limited ("ECCL")'s ongoing funds at Lloyd's ("FAL") requirements. The minimum value of cash and investments held by the Lloyd’s Capital Trust is determined on the basis of ECCL's Individual Capital Assessment, which is used to determine the required amount of FAL. As of December 31, 2015 , the fair value of assets held in the Lloyd's Capital Trust was $276.8 million , which met the minimum value required on that date. Premiums received by Syndicate 5151 are required to be received into the Lloyd's Premiums Trust Funds (the "Premiums Trust Funds"). Under the Premiums Trust Funds' deeds, assets may only be used for the payment of claims and valid expenses for a stated period of time. As of December 31, 2015 , the fair value of assets held in the Premiums Trust Funds was $231.9 million . The Company also held cash balances in Syndicate 5151 of $23.8 million . The Company's investment assets held in trust appear on the Company's Consolidated Balance Sheets as cash and cash equivalents, fixed maturity investments and accrued investment income, as appropriate. Lloyd's New Central Fund. The Lloyd's New Central Fund is available to satisfy claims if a member of Lloyd's is unable to meet its obligations to policyholders. The Lloyd's New Central Fund is funded by an annual levy imposed on members, which is determined annually by Lloyd's as a percentage of each member's written premiums ( 0.5% with respect to 2015 ). In addition, the Council of Lloyd's has power to call on members to make an additional contribution to the Lloyd's New Central Fund of up to 3% of their underwriting capacity each year should it decide that such additional contributions are necessary. The Company currently estimates that its 2015 obligation to the Lloyd's New Central Fund will be approximately $1.0 million and accrues for this obligation ratably throughout the year on a quarterly basis. Lloyd's also imposes other charges on its members and the syndicates on which they participate, including an annual subscription charge ( 0.5% of written premiums with respect to 2015 ) and an overseas business charge, levied as a percentage of gross international premiums (defined as business outside the U.K. and the Channel Islands), with the percentage depending on the type of business written. Lloyd's also has power to impose additional charges under Lloyd's Powers of Charging Byelaw. The Company currently estimates that its 2015 obligation to Lloyd's for such charges will be approximately $1.0 million and accrues for this obligation ratably throughout the year on a quarterly basis. Reinsurance commitments . In the ordinary course of business, the Company enters into reinsurance agreements that may include terms which could require the Company to collateralize certain of its obligations. Employment agreements. The Company has entered into employment agreements with certain officers that provide for equity incentive awards, executive benefits and severance payments under certain circumstances. 12. Commitments and contingencies, cont'd. Operating leases. The Company leases office space and office equipment under operating leases. Future minimum lease commitments at December 31, 2015 are as follows: Year ending December 31, Amount 2016 $ 15,375 2017 16,222 2018 15,716 2019 15,986 2020 14,408 2021 and thereafter 27,295 $ 105,002 Total lease expense under operating leases for the year ended December 31, 2015 was $16.5 million ( 2014 - $14.7 million ; 2013 - $14.7 million ). Total sublease income included in total lease expense under operating leases for the year ended December 31, 2015 was $1.3 million ( 2014 - $1.3 million ; 2013 - $0.8 million ). Legal Proceedings. The Company is party to various legal proceedings generally arising in the normal course of its business. While any proceeding contains an element of uncertainty, the Company does not believe that the eventual outcome of any litigation or arbitration proceeding to which it is presently a party could have a material adverse effect on its financial condition, results of operations or business. Pursuant to the Company's insurance and reinsurance agreements, disputes are generally required to be finally settled by arbitration.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Shareholders' Equity	13. Shareholders' equity The Company’s share capital at December 31, 2015 and 2014 is comprised as follows: 2015 2014 Preferred shares Authorized – $1.00 par value each 9,209,200 17,200,000 Issued, outstanding and fully paid: Series A preferred shares – $1.00 par value each; aggregate liquidation preference nil (2014 - $200,000) — 8,000,000 Series B preferred shares – $1.00 par value each; aggregate liquidation preference $230,000 (2014 - $230,000) 9,200,000 9,200,000 Series C preferred shares – $1.00 par value each; aggregate liquidation preference $230,000 (2014 - nil) 9,200 — 9,209,200 17,200,000 Common shares Authorized - $1.00 par value each 120,000,000 120,000,000 Issued, outstanding and fully paid: Ordinary common shares - $1.00 par value each 66,797,991 44,765,153 During 2015 , the Company issued restricted shares under its equity compensation plans (Note 16, Stock-based employee compensation and other stock plans). The common shares issued, outstanding and fully paid for at December 31, 2015 includes 1,357,279 restricted shares. On October 10, 2005, Endurance Holdings issued 8,000,000 shares of its 7.75% Non-Cumulative Preferred Shares, Series A (the "Series A Preferred Shares"). On June 1, 2011, Endurance Holdings issued 9,200,000 shares of its 7.5% Non-Cumulative Preferred Shares, Series B (the "Series B Preferred Shares"). On November 24, 2015, Endurance Holdings issued 9,200 shares of its 6.35% Non-Cumulative Preferred Shares, Series C (the "Series C Preferred Shares") (equivalent to 9,200,000 Depositary Shares), each of which represents a 1/1,000th interest in a Series C Preferred Share, $1.00 par value and $25,000.00 liquidation preference per share (equivalent to $25.00 per Depositary Share). The Series A Preferred Shares, Series B Preferred Shares and 13. Shareholders' equity, cont'd. Series C Preferred Shares sold were registered under the Securities Act of 1933, as amended. The Series A Preferred Shares and Series B Preferred Shares were issued at a price to the public of $25.00 per share. The Series C Preferred Shares were issued at a price to the public of $25,000.00 per share (equivalent to $25.00 per Depositary Share). Endurance Holdings received net proceeds of $193.5 million from its offering of Series A Preferred Shares and $224.0 million from its offering of Series B Preferred Shares, in each case after expenses and underwriting discounts. The proceeds from both offerings were used to provide additional capital to Endurance Holdings' subsidiaries and for other general corporate purposes. Endurance Holdings received net proceeds of $222.0 million from its offering of Series C Preferred Shares, after expenses and underwriting discounts. The proceeds of the offering of Series C Preferred Shares were used to redeem all of Endurance Holdings' outstanding Series A Preferred Shares and for general corporate purposes. On December 24, 2015, Endurance Holdings redeemed all 8,000,000 of its Series A Preferred Shares. The Series A Preferred shares were redeemed at a redemption price of $25.00 per share together with an amount equal to any dividends that were declared but not paid prior to December 24, 2015. The Series B Preferred Shares and Series C Preferred shares are traded on the New York Stock Exchange. The Series B Preferred Shares and Series C Preferred Shares have no stated maturity date and are redeemable in whole or in part at the option of Endurance Holdings any time after June 1, 2016 (in the case of the Series B Preferred Shares) and after December 15, 2020 (in the case of the Series C Preferred Shares) in each case at a redemption price of $25.00 per Series B Preferred Share and $25,000.00 per Series C Preferred Share (equivalent to $25.00 per Depositary Share), plus any declared and unpaid dividends, without accumulation of any undeclared dividends. Endurance Holdings may redeem all but not less than all of the Series B Preferred Shares or Series C Preferred Shares before their respective redemption dates at a redemption price of $26.00 per Series B Preferred Share and $26,000.00 per Series C Preferred Share (equivalent to $26.00 per Depositary Share), plus any declared and unpaid dividends to the date of redemption, if Endurance Holdings is required to submit a proposal to the holders of the Series B Preferred Shares or Series C Preferred Shares concerning an amalgamation, consolidation, merger, similar corporate transaction or change in Bermuda law. Dividends on the Series B Preferred Shares and Series C Preferred Shares, when, as and if declared by the Board of Directors of Endurance Holdings or a duly authorized committee of the board, accrue and are payable on the liquidation preference amount from the original issue date, quarterly in arrears on each dividend payment date, at an annual rate of 7.5% in the case of the Series B Preferred Shares and an annual rate of 6.35% in the case of the Series C Preferred Shares. Dividends on the Series B Preferred Shares and Series C Preferred Shares are not cumulative. Upon any voluntary or involuntary liquidation, dissolution or winding-up of Endurance Holdings, holders of the Series B Preferred Shares, Series C Preferred Shares and any parity shares are entitled to receive out of Endurance Holdings' assets available for distribution to shareholders, before any distribution is made to holders of Endurance Holdings' common equity securities, a liquidating distribution in the amount of $25.00 per Series B Preferred Share and $25,000.00 per Series C Preferred Share (equivalent to $25.00 per Depositary Share), plus any declared and unpaid dividends, without accumulation of any undeclared dividends. Distributions will be made pro rata as to the Series B Preferred Shares, Series C Preferred Shares and any parity shares and only to the extent of Endurance Holdings' assets, if any, that are available after satisfaction of all liabilities to creditors. In conjunction with the issuance by the Company of the Series A Preferred Shares, the Company entered into a "Declaration of Covenant" for the benefit of the holders of the 7% Senior Notes. The Covenant states that the Company will redeem its Series A Preferred Shares only if the total redemption price is less than or equal to the proceeds Endurance Holdings or its subsidiaries have received during the six months prior to the date of such redemption from the sale of certain qualifying securities that, among other things, are, with limited exceptions, pari passu with or junior to the Series A Preferred Shares upon the Company's liquidation, dissolution or winding-up; perpetual, or have a mandatory redemption or maturity date that is not less than sixty years after the initial issuance of such securities; and provide for dividends or other income distributions that are non-cumulative. The proceeds from the issuance of the Series C Preferred Shares met the requirements of the Declaration of Covenant and upon redemption of the Series A Preferred Shares, by its terms, the Declaration of Covenant was no longer available to the holders of the 7% Senior Notes. Holders of the Series B Preferred Shares and the Series C Preferred Shares have no voting rights, except with respect to certain fundamental changes in the terms of the Series B Preferred Shares or the Series C Preferred Shares and in the case of certain dividend non-payments or as otherwise required by Bermuda law or Endurance Holdings' bye-laws. 13. Shareholders' equity, cont'd. On February 25, 2016, the Company's Board of Directors authorized the repurchase of up to 5.0 million ordinary shares and share equivalents through February 28, 2018. This authorization superseded previous authorizations. No common shares were repurchased by the Company during 2015 or 2014 . Common shares repurchased by the Company are not canceled and are classified as treasury shares. The Company's treasury shares are recorded at cost as a reduction in common shares and additional paid-in capital within shareholders' equity. There were 5.0 million shares authorized for repurchase remaining at December 31, 2015 ( 2014 - 5.0 million ). Accumulated other comprehensive (loss) income The following table presents the changes in accumulated other comprehensive (loss) income balances by component for the years ended December 31, 2015 and 2014 : For the Year Ended December 31, 2015 Losses on cash flow hedges Unrealized (losses) gains on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,766 ) $ 86,100 $ (7,628 ) $ 76,706 Other comprehensive (loss) income before reclassifications — (65,941 ) (24,690 ) (90,631 ) Amounts reclassified from accumulated other comprehensive (loss) income (1) 88 (32,797 ) — (32,709 ) Net current period other comprehensive (loss) income 88 (98,738 ) (24,690 ) (123,340 ) Ending balance $ (1,678 ) $ (12,638 ) $ (32,318 ) $ (46,634 ) (1) All amounts are net of tax. For the Year Ended December 31, 2014 Losses on cash flow hedges Unrealized (losses) gains on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,855 ) $ 45,950 $ 18,636 $ 62,731 Other comprehensive (loss) income before reclassifications — 60,632 (26,264 ) 34,368 Amounts reclassified from accumulated other comprehensive (loss) income (1) 89 (20,482 ) — (20,393 ) Net current period other comprehensive (loss) income 89 40,150 (26,264 ) 13,975 Ending balance $ (1,766 ) $ 86,100 $ (7,628 ) $ 76,706 (1) All amounts are net of tax. 13. Shareholders' equity, cont'd. The following tables present the significant items reclassified out of accumulated other comprehensive (loss) income during the years ended December 31, 2015 and 2014 : For the Year Ended December 31, 2015 Details about accumulated other comprehensive (loss) income components Amount reclassified from accumulated other comprehensive (loss) income Affected line item in the Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 88 Interest expense 88 Total before income taxes — Income tax expense $ 88 Total net of income taxes Unrealized losses (gains) on available for sale securities $ (37,245 ) Net realized and unrealized gains 3,715 Net impairment losses recognized in earnings (33,530 ) Total before income taxes 733 Income tax expense $ (32,797 ) Total net of income taxes For the Year Ended December 31, 2014 Details about accumulated other comprehensive (loss) income components Amount reclassified from accumulated other comprehensive (loss) income Affected line item in the Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 89 Interest expense 89 Total before income taxes — Income tax expense $ 89 Total net of income taxes Unrealized losses (gains) on available for sale securities $ (19,406 ) Net realized and unrealized gains 625 Net impairment losses recognized in earnings (18,781 ) Total before income taxes (1,701 ) Income tax benefit $ (20,482 ) Total net of income taxes

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	14. Earnings per share The following table sets forth the computation of basic and diluted earnings per share for the years ended December 31, 2015 , 2014 and 2013 : 2015 2014 2013 Numerator: Net income available to common and participating common shareholders $ 311,345 $ 315,700 $ 279,165 Less amount allocated to participating common shareholders (1) (8,749 ) (9,118 ) (6,444 ) Net income allocated to common shareholders $ 302,596 $ 306,582 $ 272,721 Denominator: Weighted average shares - basic 52,707,390 43,368,062 42,817,624 Share equivalents: Options 118,392 47,111 — Restricted shares and restricted share units 2,721 70 583 Weighted average shares - diluted 52,828,503 43,415,243 42,818,207 Basic earnings per common share $ 5.74 $ 7.07 $ 6.37 Diluted earnings per common share $ 5.73 $ 7.06 $ 6.37 (1) Represents earnings and dividends attributable to holders of unvested restricted shares and restricted share units issued under the Company's stock compensation plans that are considered participating. In periods of loss, no losses are allocated to participating common shareholders (unvested restricted shares and restricted share units). The following table sets forth dividends declared in the years ended December 31, 2015 , 2014 and 2013 , respectively: 2015 2014 2013 Dividends declared per Series A preferred share $ 1.9375 $ 1.9375 $ 1.9375 Dividends declared per Series B preferred share $ 1.8750 $ 1.8750 $ 1.8750 Dividends declared per Series C preferred share $ — $ — $ — Dividends declared per common share $ 1.40 $ 1.36 $ 1.28

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	15. Related party transactions Fidelity Pyramis Global Advisors, a subsidiary of FMR, LLC ("Fidelity"), provides investment management services to the Company. Fidelity and its affiliates owned 3.5 million or 5.2% of Endurance Holdings' ordinary shares outstanding at December 31, 2015 and were therefore considered a related party. The Company incurred investment management fees totaling $1.3 million ( 2014 - $1.4 million ; 2013 - $1.4 million ) to this investment manager of which $0.2 million was accrued at December 31, 2015 ( 2014 - $0.3 million ). BlackRock Since 2002, subsidiaries of BlackRock Inc. ("BlackRock") have provided the Company and certain of its subsidiaries with various investment management, investment accounting and risk analysis services. BlackRock owned approximately 4.1 million or 6.1% of Endurance Holdings' ordinary shares outstanding at December 31, 2015 and were therefore considered a related party. The Company incurred expenses totaling $3.6 million ( 2014 : $3.2 million ; 2013 : $2.9 million ) for the year ended December 31, 2015 in relation to investment services rendered by BlackRock, of which $1.6 million was accrued at December 31, 2015 ( December 31, 2014 : $1.5 million ).

Stock-Based Employee Compensati

Stock-Based Employee Compensation And Other Stock Plans	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Employee Compensation And Other Stock Plans	16. Stock-based employee compensation and other stock plans At its meeting on February 28, 2007, the Company's Board of Directors adopted the 2007 Equity Incentive Plan ("2007 Plan") to allow for the issuance of equity incentives to non-employee directors of the Company and eligible employees of the Company and its subsidiaries. The 2007 Plan was approved by the Company's shareholders at the Annual General Meeting of Shareholders held on May 9, 2007. At that time, the Company's existing Amended and Restated 2002 Stock Option Plan and the Amended and Restated 2003 Non-Employee Director Incentive Plan were merged into the new 2007 Plan. The 2007 Plan allows the Company to grant to employees and non-employee directors restricted shares, restricted share units, stock appreciation rights, share bonuses, options to purchase the Company's ordinary shares and other forms of equity incentive awards, as determined by the Compensation Committee of the Company's Board of Directors. Under the terms of the 2007 Plan as amended, and after the consolidation of the Company's previous plans, a total of 2,100,000 ordinary shares were reserved for issuance. At a meeting on February 11, 2010, the Company's Board of Directors adopted a resolution to add 1,795,000 ordinary shares to the 2007 Plan, which was subsequently approved by the Company's shareholders at the Annual General Meeting of Shareholders held on May 13, 2010. Upon the acquisition of Montpelier, each Montpelier restricted share unit (including any restricted share units held by an executive officer or non-employee director) that was outstanding immediately prior to the completion of the acquisition of Montpelier subject solely to service-based vesting requirements (a "Montpelier Fixed RSU") was converted into a service-based restricted share unit under the 2007 Plan as amended, on the same terms and conditions as were applicable to such Montpelier Fixed RSU immediately prior to the completion of the acquisition of Montpelier. The number of service-based restricted share units granted was equal to the product of (i) 0.472, the exchange ratio in the Merger Agreement and (ii) the number of Montpelier common shares that were subject to such Montpelier Fixed RSU immediately prior to the completion of the acquisition. Upon completion of the acquisition of Montpelier, the number of Montpelier restricted share units that were outstanding immediately prior to the completion of the acquisition of Montpelier that were not Montpelier Fixed RSUs ("Montpelier Variable RSUs") was equal to the greater of: (i) the number of Montpelier Variable RSUs determined by using Montpelier’s actual performance as of the last completed quarter prior to the completion of the acquisition of Montpelier, as determined by the Compensation and Nominating Committee of the Montpelier board of directors prior to the completion of the acquisition of Montpelier after reasonable consultation with the Company, and (ii) the target number of Montpelier Variable RSUs. Each Montpelier Variable RSU that was outstanding immediately prior to the completion of the acquisition of Montpelier (including any Montpelier Variable RSUs that were held by an executive officer) was converted into a service-based restricted share unit under the 2007 Plan, as amended, on the same terms and conditions as were applicable to such Montpelier Variable RSU immediately prior to the completion of the acquisition of Montpelier. The number of service based restricted share units granted was equal to the product of (x) 0.472 , the exchange ratio in the Merger Agreement and (y) the number of Montpelier common shares that were subject to such Montpelier Variable RSU immediately prior to the completion of the acquisition. On August 3, 2015, the Company registered 842,755 ordinary shares for issuance. Upon completion of the acquisition of Montpelier, the Company assumed the Montpelier Re Holdings Ltd. 2012 Long-Term Incentive Plan (the "2012 Montpelier Equity Plan") and all awards outstanding thereunder and the future use of the remaining shares available for issuance under the 2012 Montpelier Equity Plan. The number of remaining shares under the 2012 Montpelier Equity Plan was adjusted pursuant to the terms of the Merger Agreement resulting in the registration of 1,025,349 ordinary shares under the 2007 Plan as amended, for future issuance thereunder. After the approval of the additional shares, a total of 5,763,104 ordinary shares were reserved for issuance. The Company issues new ordinary shares upon the issuance of share based equity incentives, such as restricted shares, or the exercise or settlement of outstanding derivative equity incentives, such as options or restricted share units. As of December 31, 2015 , 2,463,798 ( 2014 - 1,738,370 ) ordinary shares remained available for issuance under the 2007 and prior Plans. 16. Stock-based employee compensation and other stock plans, cont'd. On May 28, 2013, the Board of Directors elected John R. Charman as the Company's Chairman and Chief Executive Officer. Mr. Charman received an option to purchase 800,000 ordinary shares at an exercise price of $48.20 per share, and a grant of 708,890 restricted shares, as an employment inducement pursuant to Rule 303A.08 of the New York Stock Exchange Corporate Governance Standards and were made outside of the 2007 Plan. Options The 800,000 options awarded to Mr. Charman, as discussed above, vest annually, in five equal tranches commencing on May 28, 2013, subject to the Mr. Charman's continued employment, or in the event of certain terminations of employment and other events. Mr. Charman's options have a ten -year contractual life. The Company uses the Black-Scholes-Merton formula to estimate the value of stock options granted. Prior to 2005, the Company issued stock options to employees and non-employee directors, with exercise prices equal to the fair market values of the Company's ordinary shares on the grant dates. Options generally vested at a rate of 20% per year over a five -year term. Option awards had a 10 -year contractual life. Performance-Based Restricted Shares Commencing in March 2015, the Company issued performance-based restricted shares to certain of its senior executives under the 2007 Plan. The performance-based restricted shares represent the right to receive a specified number of ordinary shares in the future, based upon the achievement of pre-established performance criteria during the applicable performance period. Performance-based restricted shares granted to employees vest three years after the date of grant. The number of performance-based restricted shares that will ultimately vest is based upon the actual performance of the Company compared to the performance of a peer group of publicly-traded companies. Performance-based restricted shares are forfeited upon departure from the Company for any reason prior to the applicable vesting date other than in cases of death, disability, termination of employment in connection with a change in control or retirement. In the case of death, disability or change in control, 50% of the performance-based restricted shares will vest upon the date of death or disability or termination of employment in connection with a change in control. Where an employee meets certain retirement eligibility criteria, the performance-based restricted shares will continue to vest post-employment, subject to compliance with certain non-competition obligations. The fair value of the performance-based restricted shares is measured at the grant date using a Monte Carlo simulation based on pre-established targets relating to certain performance based measures achieved by the Company, with the associated expense recognized over the applicable performance and vesting period. Time-Based Restricted Shares The Company has issued time-based restricted shares to employees and non-employee directors of the Company's Board of Directors under the 2007 Plan. Restricted shares granted to employees generally vest pro-rata over a four -year period. Restricted shares are forfeited upon departure from the Company for any reason prior to the applicable vesting date other than in cases where an employee meets certain retirement eligibility criteria that allow for continuing post-employment vesting of restricted shares, subject to compliance with certain non-competition obligations. Restricted shares granted to non-employee directors vest twelve months following the date of grant and are forfeited upon departure of the non-employee director from the Company's Board of Directors for any reason prior to the applicable vesting date. The 708,890 restricted shares awarded to Mr. Charman, as discussed above, will vest annually, in five equal tranches commencing on May 28, 2013, subject to Mr. Charman’s continued employment, or in the event of certain terminations of employment and other events. Mr. Charman is party to a shareholders' agreement that restricts the sale of any vested restricted shares until 2018. The fair value of the restricted shares granted is equal to the fair market value of the Company's ordinary shares on the grant date. Compensation equal to the fair market value of the restricted shares at the measurement date is amortized and charged to income over the vesting period. 16. Stock-based employee compensation and other stock plans, cont'd. Restricted Share Units The Company has issued restricted share units to employees in select jurisdictions where the issuance of restricted shares results in unfavorable tax treatment for employee recipients. Restricted shares granted to employees generally vest pro rata over a four -year period. Restricted share units are forfeited upon departure from the Company for any reason prior to the applicable vesting date other than in cases where an employee meets certain retirement eligibility criteria which allow for continuing post-employment vesting of restricted share units, subject to compliance with certain non-competition obligations. On July 31, 2015, upon completion of the Company's acquisition of Montpelier, outstanding Montpelier restricted share units were assumed by the Company and adjusted to represent the right to receive 0.472 of the Company's ordinary shares for each outstanding Montpelier restricted share unit rounded down to the next whole number of the Company's ordinary shares. The fair value of the restricted share units granted or assumed is equal to the fair market value of the Company's ordinary shares on the grant or assumption date, as applicable. Compensation equal to the fair market value of the restricted share units at the measurement date is amortized and charged to income over the vesting period. Summary of Stock-Based Employee Compensation Activity A summary of option activity, including options held by employees, during the year ended December 31, 2015 is presented below: For the year ended December 31, 2015 Options Outstanding Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Aggregate Intrinsic Value Beginning of year 800,000 $ 48.20 Granted — — Exercised (480,000 ) 48.20 Forfeited — — Outstanding, end of year 320,000 $ 48.20 7.41 $ 5,053 Exercisable and vested options, end of year — $ — N/A $ — No options were granted during the years ended December 31, 2015 and 2014 . During the year ended December 31, 2013 , 800,000 options were granted with a weighted average grant date fair value of $10.2 million . The Company uses the Black-Scholes-Merton formula to estimate the value of stock options granted. No options expired during the years ended December 31, 2015 , 2014 and 2013 . During the years ended December 31, 2015 , 2014 and 2013, 160,000 , 160,000 and 160,000 options vested, respectively. The total intrinsic value of options exercised during the years ended December 31, 2015 , 2014 and 2013 was $9.5 million , $0.3 million , and $0.5 million , respectively. The Company received proceeds of $23.1 million from the exercise of options during the year ended December 31, 2015 . The Company issued new ordinary shares in connection with the exercise of the above options. For the years ended December 31, 2015 , 2014 and 2013 , compensation costs recognized in earnings for all options totaled $1.6 million , $3.1 million and $4.5 million , respectively. There were unrecognized stock-based compensation expenses of $1.0 million related to unvested stock options at December 31, 2015 ( 2014 - $2.6 million ). This expense is expected to be recognized in 2016 and 2017, with approximately 78.9% expected to be recognized during 2016 . 16. Stock-based employee compensation and other stock plans, cont'd. A summary of the restricted share and restricted share unit activity during the year ended December 31, 2015 , is presented below: Number of Shares/Units Aggregate Intrinsic Value Unvested, beginning of year 1,290,894 Granted and assumed 1,388,179 Settled (997,068 ) Forfeited (18,423 ) Unvested, end of year 1,663,582 Outstanding, end of year 1,663,582 $ 106,453 During the years ended December 31, 2015 , 2014 and 2013 , the Company granted an aggregate of 546,253 , 505,997 and 503,097 restricted shares and restricted share units under the 2007 Plan, and assumed 841,926 ( 2014 - nil and 2013 - nil ), the converted outstanding Montpelier restricted share units, adjusted to represent the right to receive 0.472 of the Company's ordinary shares for each outstanding Montpelier restricted share unit rounded down to the next whole number of ordinary shares. As mentioned above, the Company also granted 708,890 restricted shares to Mr. Charman outside of the 2007 Plan on May, 28, 2013. The restricted shares and restricted share units granted had weighted average grant date fair values of $91.2 million , $26.7 million and $58.1 million in the years ended December 31, 2015 , 2014 and 2013 , respectively. During the years ended December 31, 2015 , 2014 and 2013 , the aggregate fair value of restricted shares and restricted share units that vested was $60.0 million , $18.7 million and $17.1 million , respectively. For the years ended December 31, 2015 , 2014 and 2013 , compensation costs recognized in earnings for all restricted shares and restricted share units were $53.9 million , $27.9 million , and $23.5 million , respectively. At December 31, 2015 , compensation costs not yet recognized related to non-vested awards was $26.7 million ( 2014 - $23.3 million ). This expense is expected to be recognized between 2016 and 2019, with approximately 65.3% expected to be recognized during 2016 . Employee Share Purchase Plan On October 26, 2005, Endurance Holdings' shareholders approved the Employee Share Purchase Plan (the "2005 ESPP"). Following approval by the Company's shareholders in 2005, 200,000 of Endurance Holdings' ordinary shares were reserved for issuance under the 2005 ESPP. At a meeting on February 23, 2011, the Company's Board of Directors adopted a resolution to add 200,000 ordinary shares to the 2005 ESPP. The addition of 200,000 ordinary shares to the 2005 ESPP was approved by the Company's shareholders at the Annual General Meeting of Shareholders held on May 11, 2011. After approval of the additional ordinary shares, a total of 400,000 ordinary shares were reserved for issuance under the 2005 ESPP. The 2005 ESPP terminated in accordance with its terms on October 1, 2015. On February 26, 2015, the Compensation Committee of the Company's Board of Directors approved a new employee share purchase plan ("2015 ESPP"), which was approved by the Company's shareholders at its Annual General Meeting of Shareholders held on May 20, 2015. The Company ceased offering and issuing new shares under the 2005 ESPP on June 30, 2015 and began offering and issuing new shares under the 2015 ESPP after July 1, 2015. Following approval by the Company's shareholders in 2015, 300,000 of Endurance Holdings' ordinary shares were reserved for issuance under the 2015 ESPP. The 2015 ESPP is not subject to any provisions of the Employee Retirement Income Security Act of 1974 as amended, and is not a qualified plan within the meaning of Section 402(a) of the Internal Revenue Code of 1986, as amended (the "Code"). The ESPP is a qualified plan under Section 423 of the Code. Under the terms of the 2015 ESPP, employees of Endurance Holdings and certain of its subsidiaries may purchase Endurance Holdings' ordinary shares at a 15% discount to the closing market price on the purchase date. Participants are eligible to receive dividends on the shares purchased in the 2015 ESPP and are entitled to vote such shares at any Annual General or Special Meeting of Shareholders. These shares are restricted from sale, transfer or certification for one year from the purchase date. Total expenses related to this plan for the year ended December 31, 2015 was approximately $298,000 ( 2014 - $234,000 ; 2013 - $167,000 ).

Pension Plan

Pension Plan	12 Months Ended
	Dec. 31, 2015
Pension and Other Postretirement Benefit Expense [Abstract]
Pension Plan	17. Pension plan The Company provides pension benefits to eligible employees through various defined contribution plans sponsored by the Company. Under the Company's defined contribution plans, the Company makes contributions to its employees' accounts in amounts ranging from 4% to 12% of its employees’ eligible earnings. In addition, under certain defined contribution plans, employee contributions may be supplemented by matching contributions made by the Company based on the level of employee contribution. Lastly, the Company may provide additional contributions, depending on its annual financial performance. The employee and Company contributions in the defined contribution plans are invested at the election of each employee in one or more of several investment portfolios offered by third party investment advisors. Company contributions for the year ended December 31, 2015 resulted in an expense of $13.8 million being recorded in earnings ( 2014 - $12.6 million ; 2013 - $10.8 million ).

Statutory Requirements And Divi

Statutory Requirements And Dividend Restrictions	12 Months Ended
	Dec. 31, 2015
Statutory Requirements And Dividend Restrictions [Abstract]
Statutory Requirements And Dividend Restrictions	18. Statutory requirements and dividend restrictions The Company's insurance and reinsurance operations are subject to insurance and/or reinsurance laws and regulations in the jurisdictions in which they operate, the most significant of which are Bermuda, the United States, the United Kingdom and Singapore. These regulations include certain restrictions on the amount of dividends or other distributions, such as loans or cash advances, available to shareholders without prior approval of the insurance regulatory authorities. The combined statutory capital and combined statutory net income (loss) for the Company's principal operating subsidiaries, excluding Syndicate 5151, in their respective jurisdictions were as follows: Statutory capital Bermuda (1)(2) United States U.K. (3) Singapore 2015 2014 2015 2014 2015 2014 2015 2014 Required statutory capital $ 1,276,453 $ 955,903 $ 281,905 $ 244,587 $ 84,086 $ 73,741 $ 3,524 $ 3,773 Actual statutory capital 4,307,249 2,876,927 768,791 702,513 538,265 555,283 49,842 32,272 Statutory net income (loss) Bermuda United States U.K. Singapore Year ended December 31, 2015 $ 417,298 $ 70,398 $ 969 $ 17,542 Year ended December 31, 2014 453,127 28,450 4,135 4,111 Year ended December 31, 2013 454,840 (48,035 ) 27,976 8,702 (1) Bermuda statutory capital includes an investment in affiliate asset, which represents its interest in the remaining insurance and reinsurance operations of the Company included in the United States and U.K. columns above. (2) Bermuda includes the statutory capital of Endurance Bermuda and its foreign branches. (3) U.K. includes the statutory capital of Endurance U.K. Bermuda As a Bermuda holding company, Endurance Holdings is subject to the Bermuda Companies Act 1981, which limits the Company's ability to pay dividends and make distributions to its shareholders. The Company's retained earnings are unrestricted; however, the Company is not permitted to declare or pay a dividend, or make a distribution out of contributed surplus, if it is, or would after the payment be, unable to pay its liabilities as they come due, or if the realizable value of its assets would be less than its liabilities. Endurance Holdings had, as of December 31, 2015 , $2.7 billion in retained earnings and an additional $2.2 billion in contributed surplus available to declare or pay a dividend, or make a distribution out of contributed surplus, so long as Endurance Holdings remained in compliance with the Bermuda Companies Act 1981 following such dividend or distribution. Endurance Holdings relies on dividends from Endurance Bermuda to provide cash flow required for debt service and dividends to shareholders. 18. Statutory requirements and dividend restrictions, cont'd. Endurance Bermuda Endurance Bermuda is a registered Class 4 insurer under the Insurance Act 1978 ("Bermuda Insurance Act") and related regulations as amended (the "Insurance Act"). Endurance Bermuda is required to maintain minimum solvency standards and to hold available statutory capital and surplus equal to or exceeding the Enhanced Capital Requirement as determined by the Bermuda Monetary Authority ("BMA") based upon a standard mathematical model that correlates the risk underwritten to the capital that is dedicated to the business. The required capital noted in the table above has been based on the Enhanced Capital Requirement. In addition to the Enhanced Capital Requirement, Endurance Bermuda is required to maintain a minimum statutory liquidity ratio and solvency margin. For all periods presented herein, Endurance Bermuda materially exceeded these minimum requirements. Endurance Bermuda's ability to pay dividends and make capital distributions is subject to certain regulatory restrictions based on the Enhanced Capital Requirement, limits on the amount of Endurance Bermuda's premiums written and net reserves for losses and loss expenses and a minimum general capital and surplus requirement of $100.0 million . At December 31, 2015 , Endurance Bermuda can pay dividends of $1,034.4 million ( 2014 - $719.2 million ) to Endurance Holdings without prior approval under Bermuda law. Blue Water Re and Blue Water Re II Blue Water Re and Blue Water Re II are registered with the BMA as Special Purpose Insurers and are not subject to the BMA's Bermuda Solvency Capital Requirement ("BSCR"); however, the Bermuda Insurance Act limits the maximum amount of annual dividends and distributions that may be paid by Blue Water Re and Blue Water Re II. There is no minimum solvency margin or liquidity ratio that must be maintained by Blue Water Re or Blue Water Re II so long as the value of their assets exceed the value of their liabilities. At December 31, 2015 , Blue Water Re's assets exceeded the value of its liabilities by $269.6 million , and Blue Water Re II's assets exceeded the value of its liabilities by $212.5 million . Blue Water Re and Blue Water Re II did not declare or pay any dividends to their parent, BCML, during 2015 . Blue Capital Re Blue Capital Re is registered with the BMA as a Class 3A insurer. The Bermuda Insurance Act requires Blue Capital Re to maintain minimum levels of statutory capital and surplus to maintain minimum liquidity ratios and to meet minimum solvency margins. At December 31, 2015 , Blue Capital Re exceeded these minimum requirements. At December 31, 2015 , Blue Capital Re can pay dividends of $50.6 million to it's parent without prior approval under Bermuda law. BCML BCML is licensed and supervised by the BMA to carry on investment business and as an insurance agent/manager. BCML is not subject to any material minimum solvency requirements. United States Endurance U.S. Reinsurance, Endurance American, Endurance American Specialty and Endurance Risk Solutions are subject to regulation by the Delaware Department of Insurance. American Agri-Business is subject to regulation by the Texas Department of Insurance. Endurance Holdings' Delaware and Texas domiciled entities must maintain a minimum level of statutory capital as established by such jurisdictions. The amount of required capital is determined through the use of the Risk Based Capital model established by the National Association of Insurance Commissioners and adopted by Delaware and Texas. The required capital noted in the table above has been based on the Risk Based Capital model and represents the authorized control level risk based capital for these entities. Dividends for each U.S. operating subsidiary are limited to the greater of 10% of policyholders' surplus or statutory net income, excluding realized capital gains for Endurance Holdings' Delaware domiciled entities. In addition, dividends may only be declared or distributed out of earned surplus. At December 31, 2015 , Endurance U.S. Reinsurance, Endurance American, Endurance Risk Solutions and Endurance American Specialty did not have earned surplus and thus were precluded from declaring or distributing dividends during 2015 without the prior approval of the applicable insurance regulator. If the parent company is also an insurer, as is the case with Endurance American, Endurance American Specialty and Endurance Risk Solutions, the parent company or companies must also meet their own dividend eligibility requirements in order to pass along any dividends received from subsidiary insurance companies. At December 31, 2015 , American Agri-Business (with notice to the Texas Department of Insurance) could pay dividends of $3.5 million ( 2014 - $3.7 million ) without prior regulatory approval. 18. Statutory requirements and dividend restrictions, cont'd. U.K. Endurance U.K. The required and actual statutory capital amounts in the "U.K." category in the table above include amounts related to Endurance U.K. Under the jurisdiction of the United Kingdom's Prudential Regulation Authority ("PRA"), Endurance U.K. must maintain a margin of solvency at all times, which is determined based on the type and amount of insurance business written. Insurers are required to calculate their required minimum solvency margin and to report it to the PRA. The PRA also mandates calculation of an Enhanced Capital Requirement for Endurance U.K. and provides Individual Capital Guidance as an additional risk based capital assessment. At December 31, 2015 and 2014 , the actual capital for Endurance U.K. exceeded all of the capital requirements currently promulgated by the PRA. The PRA regulatory requirements impose no explicit restrictions on Endurance U.K.'s ability to pay a dividend, but Endurance U.K. would have to notify the PRA 28 days prior to any proposed dividend payment. Dividends may only be distributed from profits available for distribution. At December 31, 2015 Endurance U.K did not have retained profits available for distribution. Endurance at Lloyd's The Company participates in the Lloyd's market through Syndicate 5151, which is managed by Endurance at Lloyd's and is capitalized through ECCL. As a corporate member of Lloyd's, ECCL is subject to the oversight of the Council of Lloyd's. ECCL is required to deposit cash, securities or letters of credit (or a combination of these assets) with Lloyd's in order to satisfy its FAL requirements, which are met through the Lloyd's Capital Trust. At December 31, 2015 , ECCL had total FAL of $276.8 million which was provided by Endurance Bermuda. Singapore Endurance Bermuda's Singapore branch ("Singapore Branch") is subject to Fund Solvency and Capital Adequacy requirements by the Monetary Authority of Singapore as a foreign company in Singapore and is regulated by the Monetary Authority of Singapore pursuant to the Insurance Act in Singapore. At December 31, 2015 and 2014 , the Singapore Branch complied with the capital requirements promulgated by the Monetary Authority of Singapore. Switzerland In 2008, Endurance Bermuda established a branch in Zurich, Switzerland named Endurance Specialty Insurance Ltd. Pembroke (Bermuda) Zurich Branch. In 2015, Endurance U.K. established a branch in Zurich named Endurance Worldwide Insurance Limited, London, Zurich Branch. Swiss law does not impose additional regulation upon a Swiss branch of a foreign reinsurer.

Taxes

Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Taxes	19. Taxes The Company has operating subsidiaries and branch operations in the United States, United Kingdom, Switzerland and Singapore, which are subject to the relevant taxes in those jurisdictions. During 2014, the United States Internal Revenue Service ("IRS") completed its audit of the income tax returns of the Company's U.S. subsidiaries for 2009, 2010 and 2011. The audit results were immaterial to the operations of the Company. During 2015, the IRS commenced an examination of the 2012 income tax return of Endurance Bermuda. In February 2016, the IRS commenced an examination of the 2013 income tax return of Endurance Bermuda. Although the timing and ultimate resolution of the IRS examinations is uncertain, the Company does not expect the resolution of the examinations to result in a material change to the Company's financial position, results of operations and cash flows. As of December 31, 2015 , none of the Company's other operating subsidiaries or branch operations were under examination in any of the jurisdictions in which they operate. The Company remains subject to examination for tax years 2009 through 2015. 19. Taxes, cont'd. Endurance Holdings and Endurance Bermuda are not required to pay any income or capital gains taxes in Bermuda. Endurance Bermuda has received written assurance dated May 16, 2011 and Endurance Holdings has received written assurance dated May 17, 2011 from the Minister of Finance of Bermuda under the Exempted Undertakings Tax Protection Act of 1966 of Bermuda, as amended, that in the event any legislation is enacted in Bermuda imposing any tax computed on profits or income, or computed on any capital asset, gain or appreciation or any tax in the nature of estate duty or inheritance tax, such tax shall not be applicable to the Company until March 31, 2035 provided that the assurance is subject to the condition that it will not prevent the application of any taxes payable by the Company in respect of real property or leasehold interests in Bermuda held by it. Endurance Holdings and Endurance Bermuda intend to operate in a manner such that they will owe no United States tax other than premium excise tax and withholding taxes on certain investments. The income tax expense was as follows for the years ended December 31, 2015 , 2014 and 2013 , respectively: 2015 2014 2013 Current income tax expense $ (6,262 ) $ (1,804 ) $ (3,089 ) Deferred income tax benefit (expense) 1,900 1,414 (2,764 ) Income tax expense $ (4,362 ) $ (390 ) $ (5,853 ) Of the 2015 current income tax expense, $ 4.2 million related to taxes incurred in the United States ( 2014 - $ 1.8 million ; 2013 - $3.1 million ), $2.2 million related to taxes incurred in the United Kingdom ( 2014 and 2013 - nil ) and $0.1 million related to a tax benefit in Switzerland ( 2014 and 2013 - nil ). Of the deferred income tax benefit (expense), $0.7 million related to deferred income tax benefit in the United States ( 2014 - $1.4 million ; 2013 - $(2.8) million ), $0.2 million related to deferred income tax benefit in the United Kingdom ( 2014 and 2013 - nil ) and $1.0 million related to deferred income tax benefit in Bermuda ( 2014 and 2013 - nil ). The deferred income tax benefit in Bermuda related to amortization of intangible assets from the acquisition of Montpelier which the Company elected not to push down to Endurance at Lloyd's under current accounting guidance. A full valuation allowance has been recorded against the net asset position of Endurance Bermuda's foreign branches and a United Kingdom subsidiary. The actual income tax expense attributable to income for the years ended December 31, 2015 , 2014 and 2013 differed from the amount computed by applying the combined effective rate of 0% under Bermuda law to income before income taxes, as a result of the following: 2015 2014 2013 Computed expected tax expense $ — $ — $ — Tax (expense) benefit effect on foreign taxes (8,071 ) (1,661 ) 31,054 Change in valuation allowance 3,709 1,271 (36,907 ) $ (4,362 ) $ (390 ) $ (5,853 ) 19. Taxes, cont'd. Deferred income taxes represent the tax effect of the differences between the book and tax bases of assets and liabilities. Net deferred income tax assets and liabilities consisted of the following as of December 31, 2015 and 2014 : 2015 2014 Deferred income tax assets: Unearned premiums $ 25,172 $ 23,124 Loss reserves 27,370 29,410 Net operating loss carryforward 92,844 93,163 Deferred compensation 25,268 19,588 Deferred interest 46,568 44,951 Realized investment losses 4,972 125 Other 11,077 10,404 Total deferred income tax assets 233,271 220,765 Deferred income tax liabilities: Deferred acquisition costs (8,179 ) (10,843 ) Unrealized investment losses (gains) 1,568 (5,293 ) Unrealized foreign exchange gains (4,087 ) (2,704 ) Temporary differences related to acquisition (35,461 ) (20,344 ) Start up costs (1,565 ) (1,144 ) Other (7,561 ) (10,033 ) Total deferred income tax liabilities (55,285 ) (50,361 ) Valuation allowance (131,138 ) (121,409 ) Net deferred income tax asset $ 46,848 $ 48,995 Net income tax payments for the years ended December 31, 2015 and 2014 totaled $2.4 million and $0.9 million , respectively. The Company received net income tax refunds totaling $8.4 million for the year ended December 31, 2013 . Net operating loss carryforwards gross of tax in the amount of $155.4 million , $112.3 million , $49.9 million and $56.6 million are available for application against future taxable income in the United States, United Kingdom, Singapore and Switzerland, respectively. These net operating loss carry forwards have no expiration date in the United Kingdom and Singapore. In Switzerland and the United States, the net operating loss carry forwards expire through 2016 and 2028, respectively. A valuation allowance is provided when it is more likely than not that some portion of the deferred tax assets will not be realized. At December 31, 2015 , management has established a valuation allowance of $131.1 million ( 2014 - $121.4 million ) against net deferred tax assets in the Company's United States subsidiaries, a United Kingdom subsidiary and non-U.S. branches. The Company's income before income taxes was distributed as follows for the years ended December 31, 2015 , 2014 and 2013 , respectively: 2015 2014 2013 U.S. (domestic) $ 95,649 $ 60,112 $ 13,103 Non-U.S. (foreign) (1) 263,824 288,728 304,665 Income before income taxes $ 359,473 $ 348,840 $ 317,768 (1) The Company's non-U.S. (foreign) operating subsidiaries write business that is exposed to risks originating in the United States. Management has concluded that valuation allowances are required against the net operating loss and net capital loss carryforwards assumed as part of the Montpelier acquisition. The valuation allowances have been established as Internal Revenue Code Section 382 limits the application of net operating loss and net capital loss carryforwards following an ownership change. Accordingly, a tax effected valuation allowance of $11.3 million and $0.7 million , respectively, is required as of August 1, 2015 . The loss carryforwards available per year are $0.2 million as required by Internal Revenue Code Section 382. 19. Taxes, cont'd. As of December 31, 2015 and 2014 , the Company had no uncertain tax positions.

Condensed Unaudited Quarterly F

Condensed Unaudited Quarterly Financial Data	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Condensed Unaudited Quarterly Financial Data	20. Condensed unaudited quarterly financial data The following is a summary of the unaudited quarterly data for the year ended December 31, 2015 : Quarter Ended Quarter Ended Quarter Ended Quarter Ended Net premiums earned $ 389,859 $ 458,135 $ 557,003 $ 573,456 Net investment income 41,861 32,252 16,533 23,180 Net realized and unrealized gains (losses) 18,189 9,680 5,029 (20,238 ) Net impairment losses recognized in earnings (649 ) (424 ) (38 ) (2,604 ) Subtotal $ 449,260 $ 499,643 $ 578,527 $ 573,794 Net losses and loss expenses $ 171,936 $ 239,122 $ 263,993 $ 242,057 Acquisition, general and administrative, and corporate expenses $ 149,251 $ 152,570 $ 225,558 $ 194,726 Net foreign exchange losses (gains) $ 7,552 $ 12,981 $ 8,621 $ (2,190 ) Net income $ 108,479 $ 84,206 $ 54,530 $ 107,896 Net income attributable to non-controlling interests — — (2,707 ) (8,309 ) Net income available to Endurance Holdings $ 108,479 $ 84,206 $ 51,823 $ 99,587 Preferred dividends (8,188 ) (8,188 ) (8,188 ) (8,186 ) Net income available to Endurance Holdings' common and participating common shareholders $ 100,291 $ 76,018 $ 43,635 $ 91,401 Basic earnings per share $ 2.24 $ 1.69 $ 0.73 $ 1.36 Diluted earnings per share $ 2.23 $ 1.68 $ 0.73 $ 1.36 The following is a summary of the unaudited quarterly data for the year ended December 31, 2014 : Quarter Ended Quarter Ended Quarter Ended Quarter Ended Net premiums earned $ 396,266 $ 481,538 $ 514,895 $ 471,279 Net investment income 40,990 39,302 25,357 25,894 Net realized and unrealized gains (losses) 4,872 3,411 9,788 (3,788 ) Net impairment losses recognized in earnings (111 ) (198 ) (102 ) (214 ) Subtotal $ 442,017 $ 524,053 $ 549,938 $ 493,171 Net losses and loss expenses $ 176,896 $ 259,196 $ 290,269 $ 243,801 Acquisition, general and administrative, and corporate expenses $ 145,363 $ 165,056 $ 174,307 $ 148,374 Net foreign exchange losses (gains) $ 2,964 $ 319 $ 783 $ (227 ) Net income $ 104,480 $ 83,163 $ 76,234 $ 84,573 Preferred dividends (8,188 ) (8,188 ) (8,188 ) (8,186 ) Net income available to Endurance Holdings' common and participating common shareholders $ 96,292 $ 74,975 $ 68,046 $ 76,387 Basic earnings per share $ 2.16 $ 1.68 $ 1.52 $ 1.71 Diluted earnings per share $ 2.16 $ 1.68 $ 1.52 $ 1.70

Schedule I Summary Of Investmen

Schedule I Summary Of Investments Other Than Investments In Related Parties	12 Months Ended
	Dec. 31, 2015
Summary of Investments, Other than Investments in Related Parties [Abstract]
Schedule I Summary Of Investments Other Than Investments In Related Parties	SCHEDULE I ENDURANCE SPECIALTY HOLDINGS LTD. AND SUBSIDIARIES SUMMARY OF INVESTMENTS OTHER THAN INVESTMENTS IN RELATED PARTIES AT DECEMBER 31, 2015 (In thousands of United States dollars) Cost (1) Market Value Amount at Which Shown on the Balance Sheet Type of Investment: Fixed Maturity Investments U.S. government and government agencies and authorities $ 820,461 $ 818,468 $ 818,468 States, municipalities and political subdivisions 22,456 22,406 22,406 Foreign governments 160,941 160,976 160,976 Corporate bonds 1,920,230 1,907,687 1,907,687 Mortgage-backed securities Agency mortgage-backed securities 1,326,164 1,335,678 1,335,678 Non-agency mortgage-backed securities 792,489 788,581 788,581 Collateralized loan and debt obligations 419,795 405,128 405,128 Asset-backed securities 510,540 507,255 507,255 Total fixed maturity investments $ 5,973,076 $ 5,946,179 $ 5,946,179 Short-term investments 419,753 419,796 419,796 Equity securities 557,719 528,814 528,814 Other investments 737,069 872,617 872,617 Total Investments $ 7,687,617 $ 7,767,406 $ 7,767,406 (1) Investments in fixed maturity investments and short-term investments are shown at amortized cost.

Schedule II Condensed Financial

Schedule II Condensed Financial Statement Information Of The Registrant	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule II Condensed Financial Statement Information of the Registrant	SCHEDULE II ENDURANCE SPECIALTY HOLDINGS LTD. CONDENSED FINANCIAL STATEMENT INFORMATION OF THE REGISTRANT BALANCE SHEETS-PARENT ONLY DECEMBER 31, 2015 AND 2014 (In thousands of United States dollars except share amounts) 2015 2014 ASSETS Investment in subsidiary $ 5,582,764 $ 3,518,589 Cash and cash equivalents 3,206 240 Amounts due from subsidiaries 105,497 201,600 Goodwill and intangible assets 170,290 — Other assets 14,435 9,829 Total assets $ 5,876,192 $ 3,730,258 LIABILITIES Debt $ 707,591 $ 523,518 Deferred tax liability 17,315 — Other liabilities 27,214 21,558 Total liabilities 752,120 545,076 SHAREHOLDERS' EQUITY Preferred shares Series A, B and C, non-cumulative - 9,209,200 issued and outstanding (2014 - 17,200,000) 9,209 17,200 Common shares Common shares, ordinary - 66,797,991 issued and outstanding (2014 - 44,765,153) 66,798 44,765 Additional paid-in capital 2,145,836 598,226 Accumulated other comprehensive (loss) income (46,634 ) 76,706 Retained earnings 2,681,053 2,448,285 Total shareholders' equity available to Endurance Holdings 4,856,262 3,185,182 Non-controlling interests 267,810 — Total shareholders' equity 5,124,072 3,185,182 Total liabilities and shareholders' equity $ 5,876,192 $ 3,730,258 See accompanying notes to the consolidated financial statements. SCHEDULE II ENDURANCE SPECIALTY HOLDINGS LTD. CONDENSED FINANCIAL STATEMENT INFORMATION OF THE REGISTRANT, Cont’d. STATEMENTS OF INCOME-PARENT ONLY YEARS ENDED DECEMBER 31, 2015 , 2014 , AND 2013 (In thousands of United States dollars) 2015 2014 2013 Revenues Net investment income $ 9 $ 248 $ — Net realized and unrealized gains (losses) 332 1,957 (1,511 ) Other income 10,200 10,200 10,200 10,541 12,405 8,689 Expenses General and administrative expenses 93,237 61,325 48,017 Amortization of intangibles 6,675 — — Net foreign exchange losses (gains) 5 (1 ) — Interest expense 41,188 40,968 36,188 Total expenses 141,105 102,292 84,205 Loss before income taxes and equity in net income of subsidiaries (130,564 ) (89,887 ) (75,516 ) Equity in net income of subsidiaries 484,644 438,337 387,431 Income before income taxes 354,080 348,450 311,915 Income tax benefit 1,031 — — Net income 355,111 348,450 311,915 Net income attributable to non-controlling interests (11,016 ) — — Net income available to Endurance Holdings 344,095 348,450 311,915 Preferred dividends (32,750 ) (32,750 ) (32,750 ) Net income available to Endurance Holdings' common and participating common shareholders $ 311,345 $ 315,700 $ 279,165 See accompanying notes to the consolidated financial statements SCHEDULE II ENDURANCE SPECIALTY HOLDINGS LTD. CONDENSED FINANCIAL STATEMENT INFORMATION OF THE REGISTRANT, Cont’d. STATEMENTS OF CASH FLOWS-PARENT ONLY YEARS ENDED DECEMBER 31, 2015 , 2014 , AND 2013 (In thousands of United States dollars) 2015 2014 2013 Cash flows used in operating activities: Net income $ 355,111 $ 348,450 $ 311,915 Adjustments to reconcile net income to net cash used in operating activities: Depreciation and amortization 8,855 6,785 1,504 Net realized and unrealized (gains) losses (332 ) (1,957 ) 1,511 Deferred taxes (1,031 ) — — Stock-based compensation expense 28,604 15,093 20,708 Equity in net earnings of subsidiary (484,644 ) (438,337 ) (387,431 ) Other assets (893 ) (177 ) 2,112 Other liabilities (17,377 ) 1,626 2,942 Net cash used in operating activities (111,707 ) (68,517 ) (46,739 ) Cash flows provided by investing activities: Proceeds from sales and maturities of available for sale investments — 26,094 — Purchases of available for sale investments — (24,137 ) — Contributions of capital made to subsidiaries — — (10,389 ) Returns of capital received from subsidiaries — — 10,289 Dividends received from subsidiary 341,524 145,203 118,278 Net amounts received from subsidiaries 35,383 14,819 7,650 Purchases of fixed assets (11,626 ) — (8,298 ) Proceeds from disposals of fixed assets 6,606 19 — Net cash received for subsidiary acquisition 19,875 — — Net cash provided by investing activities 391,762 161,998 117,530 Cash flows used in financing activities: Issuance of common shares 24,823 2,305 31,884 Issuance of Series C, non-cumulative preferred shares 222,963 — — Redemption of Series A, non-cumulative preferred shares (200,000 ) — — Offering and registration costs paid (617 ) — — Bridge facility costs paid — (4,750 ) — Repurchase of common shares — — (14,584 ) Settlement of restricted shares (14,535 ) (4,039 ) (3,001 ) Repayments of debt (198,500 ) — — Dividends paid on preferred shares (32,750 ) (32,750 ) (32,750 ) Dividends paid on common shares (78,473 ) (60,524 ) (55,906 ) Net cash used in financing activities (277,089 ) (99,758 ) (74,357 ) Net increase (decrease) in cash and cash equivalents 2,966 (6,277 ) (3,566 ) Cash and cash equivalents, beginning of year 240 6,517 10,083 Cash and cash equivalents, end of year $ 3,206 $ 240 $ 6,517 See accompanying notes to the consolidated financial statements

Schedule III Supplementary Insu

Schedule III Supplementary Insurance Information	12 Months Ended
	Dec. 31, 2015
Supplementary Insurance Information [Abstract]
Schedule III Supplementary Insurance Information	SCHEDULE III ENDURANCE SPECIALTY HOLDINGS LTD. AND SUBSIDIARIES SUPPLEMENTARY INSURANCE INFORMATION YEARS ENDED DECEMBER 31, 2015 , 2014 , AND 2013 (In thousands of United States dollars) Year Ended December 31, 2015 Insurance Reinsurance Total Deferred Acquisition Costs $ 58,216 $ 197,285 $ 255,501 Reserve for Losses and Loss Expenses 2,507,361 2,003,054 4,510,415 Unearned Premiums 902,152 886,996 1,789,148 Net Premiums Earned 824,552 1,153,901 1,978,453 Net Investment Income (1) — — 113,826 Net Losses and Loss Expenses 503,561 413,547 917,108 Amortization of Deferred Acquisition Costs 80,252 267,633 347,885 Other Operating Expenses (2) 140,012 119,779 259,791 Net Premiums Written 880,373 1,070,097 1,950,470 (1) Because the Company does not manage its assets by segment, investment income is not allocated to the individual segments. (2) General and administrative expenses incurred by segments are allocated directly. Remaining general and administrative expenses not incurred by the segments are classified as corporate expenses and are not allocated to the individual business segments. Year Ended December 31, 2014 Insurance Reinsurance Total Deferred Acquisition Costs $ 34,581 $ 172,787 $ 207,368 Reserve for Losses and Loss Expenses 2,123,772 1,723,087 3,846,859 Unearned Premiums 642,779 611,740 1,254,519 Net Premiums Earned 833,912 1,030,066 1,863,978 Net Investment Income (1) — — 131,543 Net Losses and Loss Expenses 594,561 375,601 970,162 Amortization of Deferred Acquisition Costs 65,368 254,145 319,513 Other Operating Expenses (2) 148,475 98,912 247,387 Net Premiums Written 860,406 1,073,800 1,934,206 (1) Because the Company does not manage its assets by segment, investment income is not allocated to the individual segments. (2) General and administrative expenses incurred by segments are allocated directly. Remaining general and administrative expenses not incurred by the segments are classified as corporate expenses and are not allocated to the individual business segments. SCHEDULE III ENDURANCE SPECIALTY HOLDINGS LTD. AND SUBSIDIARIES SUPPLEMENTARY INSURANCE INFORMATION, Cont’d YEARS ENDED DECEMBER 31, 2015 , 2014 , AND 2013 (In thousands of United States dollars) Year Ended December 31, 2013 Insurance Reinsurance Total Deferred Acquisition Costs $ 30,095 $ 155,932 $ 186,027 Reserve for Losses and Loss Expenses 2,158,890 1,843,369 4,002,259 Unearned Premiums 452,113 566,738 1,018,851 Net Premiums Earned 946,474 1,070,010 2,016,484 Net Investment Income (1) — — 166,216 Net Losses and Loss Expenses 774,425 445,259 1,219,684 Amortization of Deferred Acquisition Costs 64,778 239,652 304,430 Other Operating Expenses (2) 136,588 100,285 236,873 Net Premiums Written 932,510 1,116,423 2,048,933 (1) Because the Company does not manage its assets by segment, investment income is not allocated to the individual segments. (2) General and administrative expenses incurred by segments are allocated directly. Remaining general and administrative expenses not incurred by the segments are classified as corporate expenses and are not allocated to the individual business segments.

Schedule IV Reinsurance

Schedule IV Reinsurance	12 Months Ended
	Dec. 31, 2015
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]
Schedule IV Reinsurance	SCHEDULE IV ENDURANCE SPECIALTY HOLDINGS LTD. AND SUBSIDIARIES REINSURANCE FOR THE YEARS ENDED DECEMBER 31, 2015 , 2014 AND 2013 (In thousands of United States dollars) Premiums Written Gross Ceded to Other Companies Assumed from Other Companies Net Amount Percentage of Amount Assumed to Net Year ended December 31, 2015 Property and liability insurance $ 2,085,901 $ 1,370,391 $ 1,234,960 $ 1,950,470 63 % Year ended December 31, 2014 Property and liability insurance $ 1,716,128 $ 959,870 $ 1,177,948 $ 1,934,206 61 % Year ended December 31, 2013 Property and liability insurance $ 1,475,429 $ 616,311 $ 1,189,815 $ 2,048,933 58 %

Schedule VI Underwriters

Schedule VI Underwriters	12 Months Ended
	Dec. 31, 2015
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Schedule of Supplemental Information for Property, Casualty Insurance Underwriters [Text Block]	SCHEDULE VI ENDURANCE SPECIALTY HOLDINGS LTD. AND SUBSIDIARIES SUPPLEMENTARY INFORMATION FOR PROPERTY AND CASUALTY INSURANCE UNDERWRITERS FOR THE YEARS ENDED DECEMBER 31, 2015 , 2014 , AND 2013 (In thousands of United States dollars) Year Ended December 31, 2015 Insurance Reinsurance Total Deferred Acquisition Costs $ 58,216 $ 197,285 $ 255,501 Reserve for Losses and Loss Expenses 2,507,361 2,003,054 4,510,415 Discount if any, Reserve for Losses and Loss Expenses — — — Unearned Premiums 902,152 886,996 1,789,148 Net Premiums Earned 824,552 1,153,901 1,978,453 Net Investment Income (1) — — 113,826 Net Losses and Loss Expenses Current Year 585,562 575,010 1,160,572 Prior Year (82,001 ) (161,463 ) (243,464 ) Amortization of Deferred Acquisition Costs 80,252 267,633 347,885 Paid Losses and Loss Expenses 633,038 500,599 1,133,637 Net Premiums Written 880,373 1,070,097 1,950,470 (1) Because the Company does not manage its assets by segment, investment income is not allocated to the individual segments. Year Ended December 31, 2014 Insurance Reinsurance Total Deferred Acquisition Costs $ 34,581 $ 172,787 $ 207,368 Reserve for Losses and Loss Expenses 2,123,772 1,723,087 3,846,859 Discount if any, Reserve for Losses and Loss Expenses — — — Unearned Premiums 642,779 611,740 1,254,519 Net Premiums Earned 833,912 1,030,066 1,863,978 Net Investment Income (1) — — 131,543 Net Losses and Loss Expenses Current Year 675,131 528,846 1,203,977 Prior Year (80,570 ) (153,245 ) (233,815 ) Amortization of Deferred Acquisition Costs 65,368 254,145 319,513 Paid Losses and Loss Expenses 700,576 457,636 1,158,212 Net Premiums Written 860,406 1,073,800 1,934,206 (1) Because the Company does not manage its assets by segment, investment income is not allocated to the individual segments. SCHEDULE VI ENDURANCE SPECIALTY HOLDINGS LTD. AND SUBSIDIARIES SUPPLEMENTARY INFORMATION FOR PROPERTY AND CASUALTY INSURANCE UNDERWRITERS, Cont’d. FOR THE YEARS ENDED DECEMBER 31, 2015 , 2014 , AND 2013 (In thousands of United States dollars) Year Ended December 31, 2013 Insurance Reinsurance Total Deferred Acquisition Costs $ 30,095 $ 155,932 $ 186,027 Reserve for Losses and Loss Expenses 2,158,890 1,843,369 4,002,259 Discount if any, Reserve for Losses and Loss Expenses — — — Unearned Premiums 452,113 566,738 1,018,851 Net Premiums Earned 946,474 1,070,010 2,016,484 Net Investment Income (1) — — 166,216 Net Losses and Loss Expenses Current Year 808,328 633,748 1,442,076 Prior Year (33,903 ) (188,489 ) (222,392 ) Amortization of Deferred Acquisition Costs 64,778 239,652 304,430 Paid Losses and Loss Expenses 797,310 564,782 1,362,092 Net Premiums Written 932,510 1,116,423 2,048,933 (1) Because the Company does not manage its assets by segment, investment income is not allocated to the individual segments.

Summary Of Significant Accoun33

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Premiums And Related Expenses	(a) Premiums and related expenses The Company's insurance premiums are earned pro rata over the term of the applicable risk period specified in the insurance policy. The Company's insurance policies cover losses occurring or claims made during the term of the policy. Generally, the Company receives a fixed premium which is identified in the policy and is recorded on the inception date of the contract or when premiums are determinable and earned evenly over the policy term. This premium will only adjust if the underlying insured values adjust. Accordingly, the Company monitors the underlying insured values and records additional or return premiums in the period in which amounts are reasonably determinable. The Company's reinsurance premiums are earned in proportion to the amount of reinsurance protection provided over the applicable risk period established in the reinsurance contract. Reinsurance contracts written on a losses occurring basis cover losses which occur during the term of the reinsurance contract, typically 12 months. Accordingly, the Company earns the premium on a losses occurring reinsurance contract evenly over the reinsurance contract term. Reinsurance contracts written on a policies attaching basis cover losses from the underlying insurance policies incepting during the terms of the reinsurance contracts. Losses under a policies attaching reinsurance contract may occur after the end date of the reinsurance contract, so long as they are losses from policies that began during the reinsurance contract period. The Company typically earns the premiums for policies attaching reinsurance contracts over a 24 -month period in proportion to the amount of reinsurance protection provided to reflect the extension of the risk period past the term of the contract and the varying levels of reinsurance protection provided during the reinsurance contract period. In addition to the applicable risk period, the Company's estimate of its reinsurance premiums written is based on the type of reinsurance contracts underwritten. For excess of loss reinsurance contracts, the deposit premium, as defined in the contract, is generally considered to be the best estimate of the reinsurance contract's written premium at inception. The Company earns reinstatement premiums upon the occurrence of a loss under the reinsurance contract. Reinstatement premiums are calculated in accordance with the contract terms based upon the ultimate loss estimate associated with each contract. For proportional reinsurance contracts, the Company estimates premium, commissions and related expenses based on broker and ceding company estimates and also utilizes judgment in establishing proportional reinsurance contract estimates. Premiums on the Company's excess of loss and proportional reinsurance contracts are estimated at the time the business is underwritten. Accordingly, this is the amount the Company records as written premium in the period the reinsurance contract is underwritten. As actual premiums are reported by the ceding companies, management evaluates the appropriateness of the original premium estimates and any adjustments to these estimates are recorded in the period in which they become known. Premiums receivable are recorded at amounts due less any allowance for estimated uncollectible premiums receivable. At December 31, 2015 , the Company had an allowance for estimated uncollectible premiums receivable of $7.4 million ( 2014 - $2.6 million ). Acquisition expenses are costs that vary with and are directly related to the successful production of new and renewal business, and consist principally of commissions and brokerage expenses. Acquisition and general and administrative expenses are shown net of commissions, other fees and expense allowances associated with and earned on ceded business. These costs are deferred and amortized over the periods in which the related premiums are earned. Deferred acquisition costs are limited to their estimated realizable value based on the related unearned premiums. Anticipated net investment income is considered in determining the recoverability of deferred acquisition costs.
Reserve For Losses And Loss Expenses	(b) Reserve for losses and loss expenses The Company’s reserve for losses and loss expenses includes case reserves and reserves for losses incurred but not reported (referred to as "IBNR reserves"). Case reserves are established for losses that have been reported, but not yet paid. IBNR reserves represent a provision for claims that have been incurred but not yet reported to the Company, as well as future loss development on losses already reported, in excess of the case reserves. Case reserves and IBNR reserves are established by management based on reports from reinsurance intermediaries, ceding companies and insureds, and consultations with independent legal counsel. In addition, reserves for IBNR losses and loss expenses are established by management based on reported losses and loss expenses, and actuarially determined estimates of ultimate losses and loss expenses. 2. Significant accounting policies, cont'd. (b) Reserve for losses and loss expenses, cont'd. The Company uses a variety of actuarial methods to estimate the ultimate losses and loss expenses incurred by the Company. One actuarial method used by the Company to estimate reserves for losses and loss expenses is the expected loss ratio approach, which is based on expected results independent of current loss reporting activity. This approach is typically used for immature loss periods (i.e., the current accident year). Another actuarial method used by the Company to estimate reserves for losses and loss expenses is known as the Bornhuetter-Ferguson method. The Bornhuetter-Ferguson method uses an initial loss estimate (expected loss technique) for each accident year by business line and type of contract. Under this method, IBNR is set equal to the initial loss estimate multiplied by the expected percent of loss yet to be reported at each valuation date. In a given quarter, if reported losses are less than expected, then the difference would result in a decrease in estimated ultimate losses. If losses are greater than expected, then the difference would result in an increase in estimated ultimate losses. A third actuarial method used by the Company to estimate reserves for losses and loss expenses is known as the loss development method. The loss development method extrapolates the current value of reported losses to ultimate expected losses by using selected reporting patterns of losses over time. The selected reporting patterns are based on historical information (organized into loss development triangles) and are adjusted to reflect the changing characteristics of the book of business written by the Company. Management uses these multiple actuarial methods, supplemented with professional judgment, to establish the best estimate of reserves for losses and loss expenses. The Company's loss and loss expense reserves are reviewed regularly, and adjustments, if any, are reflected in earnings in the period in which they become known. The establishment of new loss and loss expense reserves or the adjustment of previously recorded loss and loss expense reserves could result in significant positive or negative changes to the Company's financial condition for any particular period. While management believes the Company's estimate of loss and loss expense reserves is reasonable, the ultimate loss experience may not be reliably predicted, and it is possible losses and loss expenses may be materially different than the total reserve for losses and loss expenses recorded by the Company. Reserves for losses and loss expenses are based in part upon the estimation of losses resulting from catastrophic events. Estimation of these losses and loss expenses are based upon the Company's historical claims experience and is inherently difficult because of the Company's short operating history and the possible severity of catastrophe claims. Therefore, the Company uses both proprietary and commercially available models, as well as historical reinsurance industry catastrophe claims experience in addition to its own historical data for purposes of evaluating trends and providing an estimate of ultimate claims costs.
Reinsurance	(c) Reinsurance Reinsurance recoverable on paid and unpaid losses represent estimates of losses and loss expenses that will be recovered from reinsurers. Amounts recoverable from reinsurers are estimated in a manner consistent with the provisions of the reinsurance agreements and consistent with the establishment of the Company's reserve for losses and loss expenses. Ceding commissions earned on ceded business are classified as an offset to acquisition and general and administrative expenses. Reinsurance recoverables are recorded as assets if the reinsurer is deemed able to meet its obligations. The Company purchases reinsurance to reduce its exposure to risk of loss in certain insurance and reinsurance lines of business. Reinsurance recoverables are recorded as assets if the reinsurer is deemed able to meet its obligations. Ceded reinsurance contracts do not relieve the Company from its obligations to policyholders. The Company remains primarily liable to its policyholders for the portion reinsured to the extent that any reinsurer does not meet the obligations assumed under the reinsurance agreements.
Investments	(d) Investments The Company currently classifies its fixed maturity investments, short-term investments and equity securities as trading or available for sale. Trading securities are carried at estimated fair value, with related net realized and unrealized gains or losses included in earnings. The Company acquired a portfolio of investments classified as trading from Montpelier. In addition, in the fourth quarter of 2015, the Company started designating, on acquisition, certain fixed maturity, short-term and equity investments as trading, rather than as available for sale. The Company has elected to account for trading securities using the fair value option under current accounting guidance, as the Company believes it represents the most meaningful measurement basis for these assets and presents the Company's fixed maturity, short-term and equity investments in a manner consistent with the way in which the Company manages the investment portfolio, which is on a total investment return basis. The Company currently expects to continue to designate, in future periods, on acquisition, certain fixed maturity, short-term and equity investments as trading, rather than as available for sale. As a result, the Company currently expects its fixed maturity, short-term and equity investments balances classified as available for sale to decrease and the trading balance for each of these investments to increase. This change will result in a reduction in other-than-temporary accounting judgments the Company makes and will result in additional volatility in the Company's net income in future periods as net unrealized gains and losses on these investments will be recorded in net income, rather than as a component of accumulated other comprehensive (loss) income in shareholders' equity. 2. Significant accounting policies, cont'd. (d) Investments, cont'd. Available for sale securities are carried at estimated fair value, with related net unrealized gains or losses excluded from earnings and included in shareholders' equity as a component of accumulated other comprehensive (loss) income. Investment transactions are recorded on a trade date basis. The Company determines the fair value of its trading and available for sale investments in accordance with current accounting guidance, which defines fair value and establishes a fair value hierarchy based on inputs to the various valuation techniques used for each fair value measurement. The use of valuation techniques for any given investment requires a significant amount of judgment and consideration of factors specific to the underlying investment. Fair value measurements determined by the Company seek to maximize observable inputs and minimize the use of unobservable inputs. Current accounting guidance establishes three levels as follows: Level 1: Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2: Quoted prices for similar assets in markets that are active, quoted prices for identical or similar assets in markets that are not active or inputs that are observable either directly or indirectly. Level 2 inputs include quoted prices for similar assets or liabilities other than quoted prices in Level 1; quoted prices in markets that are not active; or other inputs that are observable or can be derived principally from or corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3: Unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities. Unobservable inputs reflect the Company's own views about the assumptions that market participants would use in pricing the asset or liability. Level 3 assets and liabilities include financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. The Company determines the estimated fair value of each individual security utilizing the highest level inputs available. Transfers between levels are assumed to occur at the end of each period. If the Company has the intent to sell a fixed maturity or short-term security classified as available for sale in an unrealized loss position or it is more likely than not that the Company will be required to sell the available for sale security, the Company deems the security to be other-than-temporarily impaired and writes down the carrying value of the security to fair value, thereby establishing a new cost basis. The amount of the write-down is recognized in earnings as an other-than-temporary impairment ("OTTI") loss. For fixed maturity and short-term investments classified as available for sale in an unrealized loss position for which a decision to sell has not been made and it is not more likely than not that the Company will be required to sell the security, the Company performs additional reviews to determine whether the investment will recover its amortized cost. If the amortized cost of the Company's fixed maturity and short-term investments classified as available for sale is, based upon the judgment of management, unlikely to be recovered, the Company writes down the investment by the amount representing the credit related portion of the decline in value, thereby establishing a new cost basis. The amount of the write-down is recognized in earnings as an OTTI loss. The new cost basis is not changed for subsequent recoveries in fair value. To the extent the Company determines that the amortized cost of the Company's fixed maturity and short-term investments classified as available for sale is likely to be recovered and the decline in value is related to non-credit factors (such as interest rates, market conditions, etc.) and not due to credit related factors, that remaining non-credit portion of the unrealized loss is recorded as a part of accumulated other comprehensive (loss) income in the shareholders' equity section of the Company's Consolidated Balance Sheets. For equity securities classified as available for sale, the Company considers its ability and intent to hold the equity security in an unrealized loss position for a reasonable period of time to allow for a full recovery. When the Company determines that the decline in value of an equity security is other-than-temporary, the Company reduces the cost of the equity security to its fair value and recognizes the loss in the Consolidated Statements of Income and Comprehensive Income. The new cost basis is not changed for subsequent recoveries in fair value. 2. Significant accounting policies, cont'd. (d) Investments, cont'd. Other investments within the Company's investment portfolio are comprised of (i) hedge funds, private investment funds and other investment funds that generally invest in senior secured bank debt, high yield credit securities, distressed debt, macro strategies, multi-strategy, equity long/short strategies, distressed real estate, and energy sector private equity ("alternative funds") and (ii) high yield loan funds ("specialty funds"). Other investments are accounted for using the equity method of accounting whereby the initial investment is recorded at cost. The carrying values of these investments are increased or decreased to reflect the Company's share of income or loss, which is included in net investment income, and are decreased for dividends. Due to the timing of the delivery of the final valuations reported by the managers of certain of our alternative and specialty funds, our investments in those funds are estimated based on the most recently available information including period end valuation statements, period end estimates, or, in some cases, prior month or quarter valuation statements.
Cash Equivalents And Short-term Investments	(e) Cash equivalents and short-term investments Cash equivalents include highly liquid short-term deposits and securities with maturities of ninety days or less at the time of purchase. Cash equivalents are valued at amortized cost, which approximates fair value due to the short-term, liquid nature of these securities. Deposits and securities with maturities greater than ninety days and less than one year are classified as short-term investments.
Intangible Assets	(f) Intangible assets Identifiable intangible assets are amortized in accordance with their useful lives. Goodwill and intangible assets with indefinite useful lives are not amortized but are tested for impairment annually at the beginning of the fourth quarter, or more often if impairment indicators arise. In making an assessment of the value of its goodwill and intangible assets, the Company uses both market based and non-market based valuations. Assumptions underlying these valuations include forecasts of discounted future cash flows and future profits and comparable transactions observed in the market, in addition to an analysis of the Company’s stock price relative to both its book value and its net income. During the fourth quarter of 2015, the Company voluntarily changed the date of its annual goodwill and indefinite-lived intangible asset impairment testing date from December 31st to October 1st. This voluntary change does not represent a material change to the Company's method of applying current accounting guidance and is preferable as it better aligns with the Company's strategic planning and forecasting process. This change will not delay, accelerate or avoid any impairment charge. This change was not applied retrospectively as it is impracticable to do so, as retrospective application would require the application of significant estimates and assumptions. It would be difficult to avoid applying hindsight and objectively determine assumptions. Therefore, the change was applied prospectively.
Offering And Registration Costs	(g) Offering and registration costs Offering and registration costs incurred in connection with equity offerings, including investment banking fees and legal fees, are deducted from the proceeds of the offerings.
Foreign Exchange	(h) Foreign exchange Assets and liabilities of foreign operations whose functional currency is not the United States dollar are translated at exchange rates in effect at the balance sheet date. Revenues and expenses of such foreign operations are translated at weighted average exchange rates during the year. The effect of the translation adjustments for foreign operations is included in accumulated other comprehensive (loss) income, net of applicable deferred income taxes. Other monetary assets and liabilities denominated in foreign currencies are revalued at the exchange rates in effect at the balance sheet date with the resulting net foreign exchange gains and losses included in earnings. Revenues and expenses denominated in foreign currencies are translated at the prevailing exchange rate on the transaction date.
Derivatives	(i) Derivatives Current accounting guidance requires the recognition of all derivative financial instruments including embedded derivative instruments, as either assets or liabilities in the Consolidated Balance Sheets at fair value. The Company may use various derivative instruments such as foreign exchange forward, future and option contracts; industry loss warranty swaps; interest rate futures, swaps, swaptions, and options; credit default swaps; LIBOR swaps; commodity futures and options; weather swaps and options; loss development covers; and to-be-announced mortgage-backed securities. These derivative instruments are used to manage exposure to interest rate and currency risk, to enhance the efficiency of the Company's investment portfolio, to economically hedge certain risks, and as part of its weather risk management business. Except for a cash flow hedge entered into in 2004 as disclosed in Note 9, Derivatives, these derivative instruments do not qualify, and are not designated, as hedges. Derivatives are recorded at fair value with changes in fair value and any gains or losses are recognized in net realized and unrealized gains, net foreign exchange losses, or other underwriting loss in the Consolidated Statements of Income and Comprehensive Income. 2. Significant accounting policies, cont'd. (i) Derivatives, cont'd. Margin balances required of counterparties are included in cash and cash equivalents. Where the Company has entered into master netting agreements with counterparties, or the Company has the legal and contractual right to offset positions, the derivative positions may be netted by the counterparty.
Income Taxes	(j) Income taxes The Company accounts for income taxes for its subsidiaries operating in taxable jurisdictions. Deferred income taxes reflect the net tax effect of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. A valuation allowance is provided when it is more likely than not that some portion of the deferred tax assets will not be realized. The accounting guidance allows for the recognition of tax benefits of uncertain tax positions only where the position is more likely than not to be sustained assuming examination by tax authorities. A liability is established for any tax benefit claimed in a tax return in excess of this threshold. Income tax related interest and penalties are included as income tax expense.
Stock Compensation And Other Stock Plans	(k) Stock compensation and other stock plans The Company has a share-based employee and non-employee director equity incentive plan ("2007 Equity Incentive Plan") and other share plans, which are described more fully in Note 16, Stock-based employee compensation and other stock plans. The fair value of the compensation cost incurred under these plans is measured at the grant date and is expensed over the period for which the employee is required to provide services in exchange for the award. Forfeiture benefits are estimated at the time of grant and incorporated in the determination of share-based compensation costs. Awards under the 2007 Equity Incentive Plan generally vest over four years for employees and one year for non-employee directors. The fair value of the restricted shares granted is equal to the fair market value of the Company's ordinary shares on the grant date. Compensation equal to the fair market value of the restricted shares at the measurement date is amortized and charged to income over the vesting period. The fair value of the performance-based restricted shares is measured at the grant date using a Monte Carlo simulation based on pre-established targets relating to certain performance based measures achieved by the Company, with the associated expense recognized over the applicable performance and vesting period. The Company uses the Black-Scholes-Merton formula to estimate the value of stock options granted.
Earnings Per Share	(l) Earnings per share The two-class method utilized by the Company is an earnings allocation formula that determines earnings per share for the holders of Endurance Holdings' ordinary shares (also referred to as "common shares") and participating common shares, which includes unvested restricted shares and restricted share units that receive cash dividends, according to dividends declared (or accumulated) and participation rights in undistributed earnings. Net income available to common and participating common shareholders is reduced by the amount of dividends declared in the current period and by the contractual amount of dividends that must be paid for the current period related to the Company's common and participating common shares. Any remaining undistributed earnings are allocated to the common and participating common shareholders to the extent that each security may share in earnings as if all of the earnings for the period had been distributed. In periods of loss, no losses are allocated to participating common shareholders. Instead, all such losses are allocated solely to the common shareholders. Basic earnings per common share are calculated by dividing net income available to common shareholders by the weighted average number of common shares outstanding. The weighted average number of common shares excludes any dilutive effect of outstanding options and convertible securities such as unvested restricted shares and restricted share units. Diluted earnings per common share are based on the weighted average number of common shares and assumes the exercise of all dilutive stock options and the vesting or conversion of all convertible securities such as unvested restricted shares using the two-class method described above.
Use Of Estimates	(m) Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported and disclosed amounts 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. Actual results could differ from those estimates.
Variable Interest Entity	(n) Variable interest entity Entities that do not have sufficient equity at risk to allow the entity to finance its activities without additional financial support or in which the equity investors, as a group, do not have the characteristic of a controlling financial interest are referred to as variable interest entities ("VIE"). A VIE is consolidated by the variable interest holder that is determined to have the controlling financial interest (primary beneficiary) as a result of having both the power to direct the activities of a VIE that most significantly impact the VIE's economic performance and the obligation to absorb losses or right to receive benefits from the VIE that could potentially be significant to the VIE. The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure, contractual terms, nature of the VIE's operations and purpose and the Company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE. The Company reassesses its VIE determination with respect to an entity on an ongoing basis. See also Note 4, Investments. Other Investments The Company is involved in the normal course of business with VIEs primarily as a passive investor in residential and commercial mortgage-backed securities and through its interests in various other investments that are structured as limited partnerships considered to be third party VIEs. The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure, contractual terms, nature of the VIE's operations and purpose, and the company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE. The Company determined that it was not the primary beneficiary for any of these investments as of December 31, 2015 and 2014 . The Company believes its exposure to loss with respect to these investments is generally limited to the investment carrying amounts reported in the Company's Consolidated Balance Sheets and any unfunded investment commitments. Collateralized Reinsurance Entities As of December 31, 2015 , Endurance Holdings and Endurance Bermuda together owned 33.3% of BCRH's common shares. BCRH is considered a VIE under U.S. GAAP and the Company has determined that it is BCRH's primary beneficiary. As a result, the Company fully consolidates the assets, liabilities and operations of BCRH and its subsidiaries within its Consolidated Financial Statements. The interests in BCRH and its subsidiaries that the Company fully consolidates that are attributable to third-party investors are reported within the Company's Consolidated Financial Statements as non-controlling interests. BCRH's shareholder rights do not include redemption features within the control of the third party shareholders. The Company reassesses its VIE determination with respect to BCRH on an ongoing basis. As of December 31, 2015 , Endurance Bermuda owned 25.1% of BCGR's ordinary shares. BCGR is considered a "voting interest entity" under U.S. GAAP and, because the Company owns less than 50% of its outstanding ordinary shares, the Company does not consolidate BCGR's assets, liabilities or operations within its Consolidated Financial Statements. However, the BCGR Cell and Blue Water Re, the Company's wholly-owned Bermuda-based special purpose insurance vehicle, are considered VIEs under U.S. GAAP and the Company has determined that it is the primary beneficiary of these entities. Therefore, as funds held in BCGR are deployed into the BCGR Cell, and ultimately into Blue Water Re, they are included in the Company's consolidated financial statements. Conversely, as funds previously deployed by BCGR and the BCGR Cell into Blue Water Re are returned to BCGR, they are no longer included in the Company's consolidated financial statements. The interests in the BCGR Cell and Blue Water Re that the Company fully consolidate that are attributable to third-party investors are reported within the Company's consolidated financial statements as non-controlling interests. BCGR's shareholder rights do not include redemption features within the control of the third party shareholders. The Company reassesses its VIE determinations with respect to the BCGR Cell and Blue Water Re on an ongoing basis.
Non-controlling interests	(o) Non-controlling interests The Company accounts for non-controlling interests in the shareholders' equity section of the Company's Consolidated Balance Sheets in accordance with current accounting guidance regarding consolidation. Net income attributable to non-controlling interest is presented separately in the Company's Consolidated Statements of Income and Comprehensive Income.
Reclassifications	(p) Reclassifications Certain comparative information has been reclassified to conform to current year presentation.
Recent Accounting Pronouncements	(q) Recent accounting pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-09, "Revenue from Contracts with Customers" ("ASU 2014-09"). ASU 2014-09 provides comprehensive guidance on the recognition of revenue from customers arising from the transfer of goods and services. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for these goods or services. ASU 2014-09 also provides guidance on accounting for certain contract costs and will also require new disclosures. ASU 2014-09 was to be effective for public business entities in annual and interim periods beginning after December 15, 2016, however, in July 2015, the FASB decided to defer by one year the effective dates of ASU 2014-09, and as a result, ASU 2014-09 will be effective for public business entities in annual and interim period beginning after December 15, 2017. Early adoption is permitted. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company's Consolidated Financial Statements. In February 2015, the FASB issued ASU 2015-02, "Amendments to the Consolidation Analysis" ("ASU 2015-02"). Under ASU 2015-02, all legal entities are required to evaluate whether they should consolidate certain legal entities. ASU 2015-02 set forth amendments: (1) modifying the evaluation of whether limited partnerships and similar legal entities are variable interest entities ("VIEs") or voting interest entities; (2) eliminating the presumption that a general partner should consolidate a limited partnership; (3) affecting the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships; and (4) providing a scope exception from consolidation guidance for certain reporting entities. ASU 2015-02 is effective for public business entities for annual and interim periods beginning after December 15, 2015. Early adoption is permitted. ASU 2015-02 may be applied retrospectively or by using a modified retrospective approach by recording a cumulative-effect adjustment to equity as of the beginning of the year of adoption. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company's Consolidated Financial Statements. 2. Significant accounting policies, cont'd. (q) Recent accounting pronouncements, cont'd. In April 2015, the FASB issued ASU 2015-03, "Simplifying the Presentation of Debt Issuance Costs" ("ASU 2015-03"). The objective of ASU 2015-03 is to simplify the presentation of debt issuance costs by requiring direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in ASU 2015-03. ASU 2015-03 is effective for public business entities in annual and interim periods beginning after December 15, 2015. Early adoption is permitted. ASU 2015-03 should be applied retrospectively, and upon transition, applicable disclosures for a change in accounting principle shall be provided, including the transition method, a description of the prior period information that has been retrospectively adjusted, and the effect of the change on the applicable financial statement line items. The Company retrospectively adopted this standard effective October 1, 2015. Debt issuance costs as at December 31, 2015, 2014 and 2013 of $3.2 million , $4.1 million , and $5.1 million , respectively, have been reclassified from other assets to debt in the Company's Consolidated Balance Sheets. This standard had no impact on the Company's Consolidated Statements of Income and Comprehensive Income. In May 2015, the FASB issued ASU 2015-07, "Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent)" ("ASU 2015-07"). The objective of ASU 2015-07 is to remove the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using net asset value per share. ASU 2015-07 is effective for public business entities in annual and interim periods beginning after December 15, 2015. Early adoption is permitted. ASU 2015-07 should be applied retrospectively. The Company retrospectively adopted this standard effective October 1, 2015. The Company's other investments were removed from the fair value hierarchy tables for the years ended December 31, 2015 and 2014 in Note 5, Fair value. This standard had no impact on the Company's Consolidated Financial Statements. In May 2015, the FASB issued ASU 2015-09, "Disclosures about Short-Duration Contracts" ("ASU 2015-09"). The objective of ASU 2015-09 is to make targeted improvements to disclosure requirements for insurance companies that issue short-duration contracts. The guidance requires additional disclosures of claims development tables, frequency of reported claims, and history of claims duration. This information is required to be disaggregated so that useful information is not obscured by either the inclusion of a large amount of insignificant detail, or the aggregation of items that have significantly different characteristics. ASU 2015-09 is effective for public business entities in annual periods beginning after December 15, 2015, and interim periods within annual periods beginning after December 15, 2016. Early adoption is permitted. ASU 2015-09 should be applied retrospectively. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company's Consolidated Financial Statements. In September 2015, the FASB issued ASU 2015-16, "Simplifying the Accounting for Measurement-Period Adjustments" ("ASU 2015-16"). ASU 2015-16 eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Instead, an acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. ASU 2015-16 is effective for public business entities in annual periods beginning after December 15, 2015, and interim periods within annual periods beginning after December 15, 2015. Early adoption is permitted. The Company is currently evaluating the impact of this guidance; however, it is not expected to have a material impact on the Company's Consolidated Financial Statements.

Investments (Policy)

Investments (Policy)	12 Months Ended
	Dec. 31, 2015
Investments [Abstract]
Other Investments	In addition to the Company's fixed maturity, short-term and equity investments, the Company invests in alternative funds and specialty funds. The Company's alternative funds and specialty funds are recorded on the Company's balance sheet as "other investments".
Gain Loss On Investments	Realized and unrealized gains and losses are recognized in earnings using the first in, first out method.
Variable Interest Entity	(n) Variable interest entity Entities that do not have sufficient equity at risk to allow the entity to finance its activities without additional financial support or in which the equity investors, as a group, do not have the characteristic of a controlling financial interest are referred to as variable interest entities ("VIE"). A VIE is consolidated by the variable interest holder that is determined to have the controlling financial interest (primary beneficiary) as a result of having both the power to direct the activities of a VIE that most significantly impact the VIE's economic performance and the obligation to absorb losses or right to receive benefits from the VIE that could potentially be significant to the VIE. The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure, contractual terms, nature of the VIE's operations and purpose and the Company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE. The Company reassesses its VIE determination with respect to an entity on an ongoing basis. See also Note 4, Investments. Other Investments The Company is involved in the normal course of business with VIEs primarily as a passive investor in residential and commercial mortgage-backed securities and through its interests in various other investments that are structured as limited partnerships considered to be third party VIEs. The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE's capital structure, contractual terms, nature of the VIE's operations and purpose, and the company's relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE. The Company determined that it was not the primary beneficiary for any of these investments as of December 31, 2015 and 2014 . The Company believes its exposure to loss with respect to these investments is generally limited to the investment carrying amounts reported in the Company's Consolidated Balance Sheets and any unfunded investment commitments. Collateralized Reinsurance Entities As of December 31, 2015 , Endurance Holdings and Endurance Bermuda together owned 33.3% of BCRH's common shares. BCRH is considered a VIE under U.S. GAAP and the Company has determined that it is BCRH's primary beneficiary. As a result, the Company fully consolidates the assets, liabilities and operations of BCRH and its subsidiaries within its Consolidated Financial Statements. The interests in BCRH and its subsidiaries that the Company fully consolidates that are attributable to third-party investors are reported within the Company's Consolidated Financial Statements as non-controlling interests. BCRH's shareholder rights do not include redemption features within the control of the third party shareholders. The Company reassesses its VIE determination with respect to BCRH on an ongoing basis. As of December 31, 2015 , Endurance Bermuda owned 25.1% of BCGR's ordinary shares. BCGR is considered a "voting interest entity" under U.S. GAAP and, because the Company owns less than 50% of its outstanding ordinary shares, the Company does not consolidate BCGR's assets, liabilities or operations within its Consolidated Financial Statements. However, the BCGR Cell and Blue Water Re, the Company's wholly-owned Bermuda-based special purpose insurance vehicle, are considered VIEs under U.S. GAAP and the Company has determined that it is the primary beneficiary of these entities. Therefore, as funds held in BCGR are deployed into the BCGR Cell, and ultimately into Blue Water Re, they are included in the Company's consolidated financial statements. Conversely, as funds previously deployed by BCGR and the BCGR Cell into Blue Water Re are returned to BCGR, they are no longer included in the Company's consolidated financial statements. The interests in the BCGR Cell and Blue Water Re that the Company fully consolidate that are attributable to third-party investors are reported within the Company's consolidated financial statements as non-controlling interests. BCGR's shareholder rights do not include redemption features within the control of the third party shareholders. The Company reassesses its VIE determinations with respect to the BCGR Cell and Blue Water Re on an ongoing basis.

Fair Value Measurement (Policy)

Fair Value Measurement (Policy)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Of Financial Instruments	The Company determines the fair value of its fixed maturity investments, short-term investments, equity securities, debt, and other assets and liabilities in accordance with current accounting guidance, which defines fair value and establishes a fair value hierarchy based on inputs to the various valuation techniques used for each fair value measurement. The Company determines the estimated fair value of each individual security utilizing the highest level inputs available. Valuation inputs by security type may include the following: • Government and agencies fixed maturity securities – These securities are generally priced by pricing services or index providers. The pricing services or index providers may use current market trades for securities with similar quality, maturity and coupon. If no such trades are available, the pricing service typically uses analytical models which may incorporate option adjusted spreads, daily interest rate data and market/sector news. The Company generally classifies the fair values of government and agencies securities in Level 2. Current issue U.S. government securities are generally valued based on Level 1 inputs, which use the market approach valuation technique. • Government guaranteed corporate fixed maturity securities – These securities are generally priced by pricing services or index providers. The pricing service or index providers may use current market trades for securities with similar quality, maturity and coupon. If no such trades are available, the pricing service typically uses analytical spread models which may incorporate inputs from the U.S. treasury curve or LIBOR. The Company generally classifies the fair values of its government guaranteed corporate securities in Level 2. • Corporate fixed maturity securities – These securities are generally priced by pricing services or index providers. The pricing services or index providers typically use discounted cash flow models that incorporate benchmark curves for treasury, swap and high issuance credits. Credit spreads are developed from current market observations for like or similar securities. The Company generally classifies the fair values of its corporate securities in Level 2. • Equity securities – These securities are generally priced by pricing services or index providers. Depending on the type of underlying equity security or equity fund, the securities are priced by pricing services or index providers based on quoted market prices in active markets or through a discounted cash flow model that incorporates benchmark curves for treasury, swap and credit for like or similar securities. The Company generally classifies the fair values of its equity securities in Level 1 or 2. • Structured securities including agency and non-agency, residential and commercial mortgage, asset-backed securities and collateralized loan and debt obligations – These securities are generally priced by broker/dealers. Broker/dealers may use current market trades for securities with similar qualities. If no such trades are available, inputs such as bid and offer, prepayment speeds, the U.S. treasury curve, swap curve and cash settlement may be used in a discounted cash flow model to determine the fair value of a security. The Company generally classifies the fair values of its structured securities in Level 2. • Other assets and liabilities – A portion of other assets and liabilities are composed of a variety of derivative instruments used to enhance the efficiency of the investment portfolio and economically hedge certain risks. These instruments are generally priced by pricing services, broker/dealers and/or recent trading activity. The market value approach valuation technique is used to estimate the fair value for these derivatives based on significant observable market inputs. Certain derivative instruments are priced by pricing services based on quoted market prices in active markets. These derivative instruments are generally classified in Level 1. Other derivative instruments are priced using industry valuation models and are considered Level 2, as the inputs to the valuation model are based on observable market inputs. Also included in this line item are proprietary, non-exchange traded derivative-based risk management products primarily used to address weather and energy risks. The trading market for these weather derivatives are generally linked to energy and agriculture commodities, weather and other natural phenomena. In instances where market prices are not available, the Company uses industry or internally developed valuation techniques such as spread option, Black Scholes, quanto and simulation modeling to determine fair value and classifies these in Level 3. These models may reference prices for similar instruments. • Debt – Outstanding debt consists of the Company's 7% Senior Notes due July 15, 2034 and 4.7% Senior Notes due October 15, 2022 (the "Senior Notes") and the Trust Preferred Securities. The fair values of these securities were obtained from a third party pricing service and pricing was based on the spread above the risk-free yield curve. These spreads are generally obtained from the new issue market, secondary trading and broker-dealer quotes. As these spreads and the yields for the risk-free yield curve are observable market inputs, the fair values of the Senior Notes and the Trust Preferred Securities are classified in Level 2. 5. Fair value measurement, cont'd. The carrying values of cash and cash equivalents, accrued investment income, other investments, net receivable on sales of investments, net payable on purchases of investments, the amount outstanding under the BCRH Credit Agreement and other financial instruments not described above approximated their fair values at December 31, 2015 and 2014 .

Reserve For Losses And Loss E36

Reserve For Losses And Loss Expenses Reserve For Losses And Loss Expenses (Policy)	12 Months Ended
	Dec. 31, 2015
Insurance Loss Reserves [Abstract]
Reserve For Losses And Loss Expenses	(b) Reserve for losses and loss expenses The Company’s reserve for losses and loss expenses includes case reserves and reserves for losses incurred but not reported (referred to as "IBNR reserves"). Case reserves are established for losses that have been reported, but not yet paid. IBNR reserves represent a provision for claims that have been incurred but not yet reported to the Company, as well as future loss development on losses already reported, in excess of the case reserves. Case reserves and IBNR reserves are established by management based on reports from reinsurance intermediaries, ceding companies and insureds, and consultations with independent legal counsel. In addition, reserves for IBNR losses and loss expenses are established by management based on reported losses and loss expenses, and actuarially determined estimates of ultimate losses and loss expenses. 2. Significant accounting policies, cont'd. (b) Reserve for losses and loss expenses, cont'd. The Company uses a variety of actuarial methods to estimate the ultimate losses and loss expenses incurred by the Company. One actuarial method used by the Company to estimate reserves for losses and loss expenses is the expected loss ratio approach, which is based on expected results independent of current loss reporting activity. This approach is typically used for immature loss periods (i.e., the current accident year). Another actuarial method used by the Company to estimate reserves for losses and loss expenses is known as the Bornhuetter-Ferguson method. The Bornhuetter-Ferguson method uses an initial loss estimate (expected loss technique) for each accident year by business line and type of contract. Under this method, IBNR is set equal to the initial loss estimate multiplied by the expected percent of loss yet to be reported at each valuation date. In a given quarter, if reported losses are less than expected, then the difference would result in a decrease in estimated ultimate losses. If losses are greater than expected, then the difference would result in an increase in estimated ultimate losses. A third actuarial method used by the Company to estimate reserves for losses and loss expenses is known as the loss development method. The loss development method extrapolates the current value of reported losses to ultimate expected losses by using selected reporting patterns of losses over time. The selected reporting patterns are based on historical information (organized into loss development triangles) and are adjusted to reflect the changing characteristics of the book of business written by the Company. Management uses these multiple actuarial methods, supplemented with professional judgment, to establish the best estimate of reserves for losses and loss expenses. The Company's loss and loss expense reserves are reviewed regularly, and adjustments, if any, are reflected in earnings in the period in which they become known. The establishment of new loss and loss expense reserves or the adjustment of previously recorded loss and loss expense reserves could result in significant positive or negative changes to the Company's financial condition for any particular period. While management believes the Company's estimate of loss and loss expense reserves is reasonable, the ultimate loss experience may not be reliably predicted, and it is possible losses and loss expenses may be materially different than the total reserve for losses and loss expenses recorded by the Company. Reserves for losses and loss expenses are based in part upon the estimation of losses resulting from catastrophic events. Estimation of these losses and loss expenses are based upon the Company's historical claims experience and is inherently difficult because of the Company's short operating history and the possible severity of catastrophe claims. Therefore, the Company uses both proprietary and commercially available models, as well as historical reinsurance industry catastrophe claims experience in addition to its own historical data for purposes of evaluating trends and providing an estimate of ultimate claims costs.

Reinsurance (Policy)

Reinsurance (Policy)	12 Months Ended
	Dec. 31, 2015
Reinsurance Transactions [Abstract]
Reinsurance	(c) Reinsurance Reinsurance recoverable on paid and unpaid losses represent estimates of losses and loss expenses that will be recovered from reinsurers. Amounts recoverable from reinsurers are estimated in a manner consistent with the provisions of the reinsurance agreements and consistent with the establishment of the Company's reserve for losses and loss expenses. Ceding commissions earned on ceded business are classified as an offset to acquisition and general and administrative expenses. Reinsurance recoverables are recorded as assets if the reinsurer is deemed able to meet its obligations. The Company purchases reinsurance to reduce its exposure to risk of loss in certain insurance and reinsurance lines of business. Reinsurance recoverables are recorded as assets if the reinsurer is deemed able to meet its obligations. Ceded reinsurance contracts do not relieve the Company from its obligations to policyholders. The Company remains primarily liable to its policyholders for the portion reinsured to the extent that any reinsurer does not meet the obligations assumed under the reinsurance agreements.

Derivatives (Policy)

Derivatives (Policy)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Accounting policy for derivatives	The interest rate lock agreement was designated as a "cash flow hedge" under current accounting guidance and accordingly, the fair value of the derivative was recorded in other comprehensive income and is being recognized as a component of interest expense in the Consolidated Statements of Income and Comprehensive Income as the interest expense related to the 7% Senior Notes affects earnings. These loans are fully collateralized, are generally outstanding for a short period of time and are presented as part of cash and cash equivalents in the Consolidated Balance Sheets. None of the Company's derivatives are designated as hedges under current accounting guidance, with the exception of the interest rate lock. The Company's objectives for holding these derivatives are as follows: Interest Rate Futures, Swaps, Swaptions and Options - to manage exposure to interest rate risk, which can include increasing or decreasing its exposure to this risk through modification of the portfolio composition and duration. Industry Loss Warranty ("ILW") Swaps - to manage underwriting risk. The Company has entered into ILW swap contracts which provide reinsurance-like protection to the Company for specific loss events associated with certain lines of its business. The Company has also sold ILW protection, which provides reinsurance-like protection to third parties for specific loss events. Foreign Exchange Forwards, Futures and Options - as part of its overall currency risk management and investment strategies. Credit Default Swaps - to manage market exposures. The Company may assume or economically hedge credit risk through credit default swaps to replicate or hedge investment positions. The original term of these credit default swaps is generally five years or less. To-Be-Announced Mortgage-backed Securities (“TBAs”) - to enhance investment performance and as part of the overall investment strategy. TBAs represent commitments to purchase or sell a future issuance of agency mortgage-backed securities. For the period between the purchase of a TBA and issuance of the underlying securities, the Company’s position is accounted for as a derivative. Energy and Weather Contracts - to address weather and energy risks. The Company may purchase or sell contracts with financial settlements based on the performance of an index linked to a quantifiable weather element, such as temperature, precipitation, snowfall or windspeed, and structures with multiple risk triggers indexed to a quantifiable weather element and a weather sensitive commodity price, such as temperature and electrical power or natural gas. Generally, the Company’s current portfolio of energy and weather derivative contracts is of comparably short duration and such contracts are predominantly seasonal in nature. LIBOR Swap – to establish future net cash flows in connection with the Trust Preferred Securities for the 5 -year period beginning March 30, 2012 as if these securities bore interest at a fixed rate of 4.905% . See Note 8, Debt and financing arrangements. Loss Development Cover – as part of the sale of Montpelier U.S. Insurance Company ("MUSIC") to Selective Insurance Group, Inc. ("Selective"), Montpelier Reinsurance Ltd. ("Montpelier Re", now Endurance Bermuda) entered into a loss development cover with MUSIC which ensures that MUSIC's reserve for losses and loss expenses relating to retained business written on or prior to December 31, 2011 remains adequate. Under the loss development cover, any future adverse development associated with such retained reserves will be protected by Endurance Bermuda and any future favorable development associated with such retained reserves will benefit Endurance Bermuda.
Offsetting of derivatives policy	At December 31, 2015 and 2014 , the Company's derivative instruments were recorded on a gross basis in the Consolidated Balance Sheets.

Segment Reporting (Policy)

Segment Reporting (Policy)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment Reporting	The Company attributes gross premiums written to the geographic region in which the risks originate. The determination of the Company's business segments is based on how the Company monitors the performance of its underwriting operations. The Company has two reportable business segments, Insurance and Reinsurance. • Insurance – This segment is comprised of four lines of business: agriculture, casualty and other specialty, professional lines, and property, marine/energy and aviation. The agriculture line of business is comprised of multi-peril crop insurance, crop hail, livestock risk protection and other agriculture risk management products. The casualty and other specialty line of business is comprised of the insurance and facultative reinsurance of third party liability exposures, including casualty and healthcare liability. The professional line of business includes directors' and officers' liability, errors and omissions, employment practices liability, environmental liability and pension trust liability insurance. The property, marine/energy and aviation line of business is comprised of the insurance and facultative reinsurance of commercial properties, inland marine and ocean marine insurance, energy insurance, and general liability and property coverages for a wide range of general aviation risks. • Reinsurance – This segment is comprised of five lines of business: catastrophe, property, casualty, professional lines, and specialty. The catastrophe line of business includes reinsurance for catastrophic perils on a treaty basis. The property line of business includes proportional and excess of loss reinsurance of personal and commercial exposures. The casualty line of business is comprised of third party liability exposures, clash and workers' compensation coverages. The professional line of business includes directors' and officers' liability, errors and omissions, employment practices liability, environmental liability and pension trust liability reinsurance. The specialty line of business includes the reinsurance of aviation and space business and proportional and non-proportional reinsurance of hull and cargo insurance business, and proportional and excess of loss coverages of contract and commercial surety business, personal accident coverages, political risk coverages, weather risk management products and agriculture coverages for weather related perils as well as protection from yield and price risks. 10. Segment reporting, cont'd. Management measures Insurance and Reinsurance segment results on the basis of the combined ratio, which is obtained by dividing the sum of the net losses and loss expenses, acquisition expenses and general and administrative expenses by net premiums earned. When purchased within a single line of business, ceded reinsurance and recoveries are accounted for within that line of business. When purchased across multiple lines of business, ceded reinsurance and recoveries are allocated to the lines of business in proportion to the related risks assumed. The Company does not manage its assets by segment; accordingly, investment income and total assets are not allocated to the individual business segments. General and administrative expenses incurred by segments are allocated directly. Remaining general and administrative expenses not incurred by the segments are classified as corporate expenses and are not allocated to the individual business segments. Ceded reinsurance and recoveries are recorded within the business segment to which they apply. The underwriting results of Montpelier are included in the Company's segment results from August 1, 2015.

Goodwill And Intangible Assets

Goodwill And Intangible Assets Goodwill And Intangible Assets (Policies)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	(f) Intangible assets Identifiable intangible assets are amortized in accordance with their useful lives. Goodwill and intangible assets with indefinite useful lives are not amortized but are tested for impairment annually at the beginning of the fourth quarter, or more often if impairment indicators arise. In making an assessment of the value of its goodwill and intangible assets, the Company uses both market based and non-market based valuations. Assumptions underlying these valuations include forecasts of discounted future cash flows and future profits and comparable transactions observed in the market, in addition to an analysis of the Company’s stock price relative to both its book value and its net income. During the fourth quarter of 2015, the Company voluntarily changed the date of its annual goodwill and indefinite-lived intangible asset impairment testing date from December 31st to October 1st. This voluntary change does not represent a material change to the Company's method of applying current accounting guidance and is preferable as it better aligns with the Company's strategic planning and forecasting process. This change will not delay, accelerate or avoid any impairment charge. This change was not applied retrospectively as it is impracticable to do so, as retrospective application would require the application of significant estimates and assumptions. It would be difficult to avoid applying hindsight and objectively determine assumptions. Therefore, the change was applied prospectively.

Stock-Based Employee Compensa41

Stock-Based Employee Compensation And Other Stock Plans (Policy)	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Based Compensation RSU Plans [Policy]	The Company uses the Black-Scholes-Merton formula to estimate the value of stock options granted. The fair value of the restricted share units granted or assumed is equal to the fair market value of the Company's ordinary shares on the grant or assumption date, as applicable. Compensation equal to the fair market value of the restricted share units at the measurement date is amortized and charged to income over the vesting period.
Stock Compensation And Other Stock Plans	(k) Stock compensation and other stock plans The Company has a share-based employee and non-employee director equity incentive plan ("2007 Equity Incentive Plan") and other share plans, which are described more fully in Note 16, Stock-based employee compensation and other stock plans. The fair value of the compensation cost incurred under these plans is measured at the grant date and is expensed over the period for which the employee is required to provide services in exchange for the award. Forfeiture benefits are estimated at the time of grant and incorporated in the determination of share-based compensation costs. Awards under the 2007 Equity Incentive Plan generally vest over four years for employees and one year for non-employee directors. The fair value of the restricted shares granted is equal to the fair market value of the Company's ordinary shares on the grant date. Compensation equal to the fair market value of the restricted shares at the measurement date is amortized and charged to income over the vesting period. The fair value of the performance-based restricted shares is measured at the grant date using a Monte Carlo simulation based on pre-established targets relating to certain performance based measures achieved by the Company, with the associated expense recognized over the applicable performance and vesting period. The Company uses the Black-Scholes-Merton formula to estimate the value of stock options granted.

Acquisition of Montpelier (Tabl

Acquisition of Montpelier (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following table summarizes the results of Montpelier since July 31, 2015 that have been included in the Company's Consolidated Statement of Income and Comprehensive Income for the year ended December 31, 2015 : For the period from July 31, 2015 to December 31, 2015 Total revenues $ 225,899 Net income attributable to the Company's common shareholders (1) 54,768 (1) Includes $52.7 million of compensation-related costs associated with terminating employees of Montpelier. The Company's total purchase price for Montpelier at July 31, 2015 was calculated as follows: Consideration paid by Endurance Holdings Number of Montpelier common shares outstanding immediately prior to the closing of the acquisition 43,827,753 Exchange ratio 0.472 Total Company ordinary shares 20,686,699 Company ordinary share closing price on July 31, 2015 $ 69.49 Total value of Company ordinary shares $ 1,437,519 Fair value of restricted share units attributable to service period prior to Closing Date (1) $ 33,327 Total consideration $ 1,470,846 Special Dividend paid by Montpelier Number of Montpelier common shares and restricted share units eligible for special dividend 45,611,810 Special dividend paid per Montpelier common share and restricted share unit $ 9.89 Total special dividend consideration paid to Montpelier common shareholders and Montpelier equity award holders $ 451,101 Total consideration received by Montpelier common shareholders and Montpelier equity award holders $ 1,921,947 Less: Special Dividend paid by Montpelier (451,101 ) Net purchase price $ 1,470,846 (1) Outstanding Montpelier restricted share units were assumed by the Company and adjusted as of the Closing Date to represent the right to receive 0.472 Company ordinary shares for each outstanding Montpelier restricted share unit rounded down to the next whole number of Company ordinary shares. The fair value of the Montpelier restricted share units was determined based on the closing price of the Company's ordinary shares on the Closing Date. The resulting fair value of the restricted share units was apportioned as purchase consideration based on service provided to Montpelier as of the Closing Date with the remaining fair value of these restricted share units to be recognized prospectively over the restricted share units' remaining vesting period.
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The Company identified finite lived intangible assets of $293.2 million , which will be amortized over a weighted average period of 8 years, identifiable indefinite lived intangible assets of $57.6 million , and certain other 3. Acquisition of Montpelier, cont'd. adjustments to the fair values of the assets acquired, liabilities assumed and shareholders' equity of Montpelier at July 31, 2015 as summarized in the table below: Montpelier shareholders' equity attributable to controlling interest prior to Special Dividend $ 1,560,255 Cash and cash equivalents (Special Dividend on Montpelier common shares and Montpelier equity awards) (451,101 ) Adjusted shareholders' equity of Montpelier as of July 31, 2015 1,109,154 Adjustments for fair value, by applicable balance sheet caption: Assets: Fixed maturity investments, trading at fair value (11,100 ) Deferred acquisition costs (91,713 ) Reinsurance recoverable on unpaid losses (675 ) Other assets (12,459 ) Liabilities: Reserve for losses and loss expenses 10,822 Debt 21,123 Deferred tax liability (18,346 ) Equity: Non-controlling interest 25,615 Total adjustments for fair value by applicable balance sheet caption (76,733 ) Adjustments for fair value of the identifiable intangible assets: Identifiable indefinite lived intangible assets (insurance licenses, Lloyd's syndicate capacity and asset management agreements) 57,600 Identifiable finite lived intangible assets (non-contractual relationships, Lloyd's syndicate distribution channel, renewal rights, value of business acquired ("VOBA"), trade names, non-compete agreements and asset management agreements) 293,200 Total adjustments for fair value by applicable balance sheet caption and identifiable intangible assets 274,067 Estimated fair value of net assets acquired and identifiable intangible assets 1,383,221 Total consideration paid by Endurance Holdings 1,470,846 Estimated total consideration over the fair value of net assets acquired assigned to goodwill $ 87,625
Finite-Lived and Indefinite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]	Identifiable intangible assets at July 31, 2015 consisted of the following, and are included in goodwill and other intangible assets on the Company's consolidated balance sheets: Amount Economic Useful Life Key non-contractual relationships $ 71,800 10 Other non-contractual relationships 22,400 3 Trade names 1,800 Various Insurance licenses 1,900 Indefinite Non-compete agreements 5,700 Various Lloyd's syndicate capacity 48,300 Indefinite Lloyd's syndicate distribution channel 18,400 10 Renewal rights 82,100 15 VOBA 88,400 2 Asset management agreements 10,000 Various Identifiable intangible assets at July 31, 2015 $ 350,800
Business Acquisition, Pro Forma Information [Table Text Block]	The following table presents unaudited pro forma consolidated financial information for the years ended December 31, 2015 and 2014 and assumes the acquisition of Montpelier occurred on January 1, 2014. The unaudited pro forma consolidated financial information is provided for informational purposes only and is not necessarily, and should not be assumed to be, an indication of the results that would have been achieved had the transaction been completed as of January 1, 2014 or that may be achieved in the future. The unaudited pro forma consolidated financial information does not give consideration to the impact of possible revenue enhancements, expense efficiencies, synergies or asset dispositions that may result from the acquisition of Montpelier. In addition, unaudited pro forma consolidated financial information does not include the effects of costs associated with any restructuring or integration activities resulting from the acquisition of Montpelier, as they are nonrecurring. Year Ended December 31, 2015 2014 Total revenues $ 2,452,410 $ 2,668,604 Net income available to Endurance Holdings' common shareholders 443,817 388,371

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Investments [Abstract]
Composition Of Net Investment Income	The components of net investment income for the years ended December 31, 2015 , 2014 and 2013 are as follows: 2015 2014 2013 Fixed income investments $ 132,786 $ 118,084 $ 109,118 Equity securities 8,209 5,689 3,956 Other investments (13,553 ) 19,609 64,321 Cash and cash equivalents 2,870 2,445 2,752 $ 130,312 $ 145,827 $ 180,147 Investment expenses (16,486 ) (14,284 ) (13,931 ) Net investment income $ 113,826 $ 131,543 $ 166,216
Contractual Maturities Of Fixed Maturity And Short-Term Investments	Contractual maturities of the Company's fixed maturity and short-term investments are shown below as of December 31, 2015 and 2014 . Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. December 31, 2015 December 31, 2014 Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 622,070 $ 622,248 $ 126,921 $ 127,821 Due after one year through five years 2,005,456 1,995,502 1,627,154 1,632,259 Due after five years through ten years 683,147 676,932 474,959 479,138 Due after ten years 33,168 34,651 43,314 46,720 Residential mortgage-backed securities 1,301,083 1,311,373 1,149,536 1,175,006 Commercial mortgage-backed securities 817,570 812,886 960,598 979,419 Collateralized loan and debt obligations 419,795 405,128 247,510 248,011 Asset-backed securities 510,540 507,255 411,529 413,221 Total $ 6,392,829 $ 6,365,975 $ 5,041,521 $ 5,101,595
Fair Value of Trading Investments	The following table summarizes the fair value of the fixed maturity investments, short-term investments and equity securities classified as trading at December 31, 2015 . The Company had no securities classified as trading as of December 31, 2014 . December 31, 2015 Fixed maturity investments U.S. government and agencies securities $ 319,674 U.S. state and municipal securities 5,559 Foreign government securities 49,861 Government guaranteed corporate securities 38,201 Corporate securities 532,192 Residential mortgage-backed securities 258,574 Commercial mortgage-backed securities 127,124 Collateralized loan and debt obligations (1) 103,219 Asset-backed securities 152,756 Total fixed maturity investments 1,587,160 Short-term investments 394,111 Total fixed income investments $ 1,981,271 Equity securities Equity investments $ 48 Preferred equity investments 553 Short-term fixed income fund 14,628 Total equity securities $ 15,229 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $38.5 million at December 31, 2015 .
Other Investments	The following table summarizes the composition and redemption restrictions of other investments as of December 31, 2015 and 2014 : December 31, 2015 Market Value Unfunded Commitments Ineligible for Redemption in 2016 Alternative funds Hedge funds $ 704,966 $ — $ 57,876 Private investment funds 80,690 102,070 80,690 Other investment funds 23,465 30,000 24,958 Total alternative funds 809,121 132,070 163,524 Specialty funds High yield loan funds 63,496 — — Total specialty funds 63,496 — — Total other investments $ 872,617 $ 132,070 $ 163,524 December 31, 2014 Market Value Unfunded Commitments Ineligible for Redemption in 2015 Alternative funds Hedge funds $ 411,280 $ — $ 10,580 Private investment funds 74,664 70,542 74,664 Total alternative funds 485,944 70,542 85,244 Specialty funds High yield loan funds 55,510 — — Total specialty funds 55,510 — — Total other investments $ 541,454 $ 70,542 $ 85,244
Net Realized And Unrealized Gains	The analysis of gross realized gains and losses, net unrealized gains and losses on trading securities, intangible asset impairment loss, and the change in the fair value of investment-related derivative financial instruments for the years ended December 31, 2015 , 2014 and 2013 are as follows: 2015 2014 2013 Gross realized gains on investment sales $ 65,881 $ 35,921 $ 40,018 Gross realized losses on investment sales (28,636 ) (16,515 ) (25,521 ) Net unrealized losses on trading securities (24,257 ) — — Intangible asset impairment loss (1) — (5,450 ) — Change in fair value of derivative financial instruments (2) (328 ) 327 667 Net realized and unrealized gains $ 12,660 $ 14,283 $ 15,164 (1) For additional information on the Company's intangible assets, see Note 11, Goodwill and intangible assets. (2) For additional information on the Company's derivative financial instruments, see Note 9, Derivatives.
Amortized Cost, Fair Value, Unrealized Gains and Losses for Available for Sale Securities	December 31, 2014 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity investments U.S. government and agencies securities $ 582,970 $ 6,471 $ (2,030 ) $ 587,411 U.S. state and municipal securities 39,340 191 (118 ) 39,413 Foreign government securities 239,217 2,983 (1,664 ) 240,536 Government guaranteed corporate securities 47,436 675 (9 ) 48,102 Corporate securities 1,354,370 12,742 (5,650 ) 1,361,462 Residential mortgage-backed securities 1,149,536 27,542 (2,072 ) 1,175,006 Commercial mortgage-backed securities 960,598 21,374 (2,553 ) 979,419 Collateralized loan and debt obligations (1) 247,510 1,449 (948 ) 248,011 Asset-backed securities 411,529 2,265 (573 ) 413,221 Total fixed maturity investments $ 5,032,506 $ 75,692 $ (15,617 ) $ 5,092,581 Short-term investments 9,015 — (1 ) 9,014 Total fixed income investments $ 5,041,521 $ 75,692 $ (15,618 ) $ 5,101,595 Equity securities Equity investments $ 176,167 $ 29,660 $ (3,292 ) $ 202,535 Emerging market debt funds 60,826 — (676 ) 60,150 Convertible funds 46,331 — (220 ) 46,111 Preferred equity investments 13,858 2,022 (44 ) 15,836 Short-term fixed income fund 6,740 — (4 ) 6,736 Total equity securities $ 303,922 $ 31,682 $ (4,236 ) $ 331,368 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $15.2 million . The amortized cost, fair value and related gross unrealized gains and losses on the Company's securities classified as available for sale at December 31, 2015 and 2014 are as follows: December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity investments U.S. government and agencies securities $ 499,386 $ 2,561 $ (3,153 ) $ 498,794 U.S. state and municipal securities 16,908 120 (181 ) 16,847 Foreign government securities 110,893 803 (581 ) 111,115 Government guaranteed corporate securities 19,248 311 (7 ) 19,552 Corporate securities 1,323,276 5,698 (11,232 ) 1,317,742 Residential mortgage-backed securities 1,041,540 16,400 (5,141 ) 1,052,799 Commercial mortgage-backed securities 689,078 4,737 (8,053 ) 685,762 Collateralized loan and debt obligations (1) 304,915 796 (3,802 ) 301,909 Asset-backed securities 356,753 585 (2,839 ) 354,499 Total fixed maturity investments $ 4,361,997 $ 32,011 $ (34,989 ) $ 4,359,019 Short-term investments 25,657 28 — 25,685 Total fixed income investments $ 4,387,654 $ 32,039 $ (34,989 ) $ 4,384,704 Equity securities Equity investments $ 418,822 $ 6,834 $ (31,875 ) $ 393,781 Emerging market debt funds 61,874 — (5,453 ) 56,421 Convertible funds 46,331 — (146 ) 46,185 Preferred equity investments 15,275 1,946 (151 ) 17,070 Short-term fixed income fund 127 1 — 128 Total equity securities $ 542,429 $ 8,781 $ (37,625 ) $ 513,585 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $11.4 million .
Available For Sale Securities In An Unrealized Loss Position	Less than 12 months 12 months or greater Total December 31, 2014 Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Fixed maturity investments U.S. government and agencies securities $ (481 ) $ 155,350 $ (1,549 ) $ 45,993 $ (2,030 ) $ 201,343 U.S. state and municipal securities (47 ) 3,295 (71 ) 6,841 (118 ) 10,136 Foreign government securities (1,378 ) 37,904 (286 ) 4,306 (1,664 ) 42,210 Government guaranteed corporate securities (9 ) 4,598 — — (9 ) 4,598 Corporate securities (4,023 ) 533,139 (1,627 ) 84,278 (5,650 ) 617,417 Residential mortgage-backed securities (260 ) 62,832 (1,812 ) 108,899 (2,072 ) 171,731 Commercial mortgage-backed securities (1,068 ) 180,222 (1,485 ) 78,412 (2,553 ) 258,634 Collateralized loan and debt obligations (876 ) 176,439 (72 ) 6,491 (948 ) 182,930 Asset-backed securities (415 ) 199,205 (158 ) 19,095 (573 ) 218,300 Total fixed maturity investments $ (8,557 ) $ 1,352,984 $ (7,060 ) $ 354,315 $ (15,617 ) $ 1,707,299 Short-term investments (1 ) 1,953 — — (1 ) 1,953 Total fixed income investments $ (8,558 ) $ 1,354,937 $ (7,060 ) $ 354,315 $ (15,618 ) $ 1,709,252 Equity securities Equity investments $ (3,292 ) $ 53,591 $ — $ — $ (3,292 ) $ 53,591 Emerging market debt funds (676 ) 60,150 — — (676 ) 60,150 Convertible funds (220 ) 46,111 — — (220 ) 46,111 Preferred equity investments (44 ) 4,449 — — (44 ) 4,449 Short-term fixed income fund (4 ) 6,736 — — (4 ) 6,736 Total equity securities $ (4,236 ) $ 171,037 $ — $ — $ (4,236 ) $ 171,037 (1) Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive (loss) income at December 31, 2014 . The following tables summarize, for all available for sale securities in an unrealized loss position at December 31, 2015 and 2014 , the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position. Less than 12 months 12 months or greater Total December 31, 2015 Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Fixed maturity investments U.S. government and agencies securities $ (2,175 ) $ 347,024 $ (978 ) $ 16,669 $ (3,153 ) $ 363,693 U.S. state and municipal securities (96 ) 9,662 (85 ) 695 (181 ) 10,357 Foreign government securities (404 ) 31,881 (177 ) 3,966 (581 ) 35,847 Government guaranteed corporate securities (7 ) 1,692 — — (7 ) 1,692 Corporate securities (9,222 ) 830,349 (2,010 ) 51,024 (11,232 ) 881,373 Residential mortgage-backed securities (3,378 ) 365,082 (1,763 ) 79,355 (5,141 ) 444,437 Commercial mortgage-backed securities (6,708 ) 436,387 (1,345 ) 42,246 (8,053 ) 478,633 Collateralized loan and debt obligations (3,107 ) 224,520 (695 ) 48,167 (3,802 ) 272,687 Asset-backed securities (2,624 ) 311,814 (215 ) 12,880 (2,839 ) 324,694 Total fixed income investments $ (27,721 ) $ 2,558,411 $ (7,268 ) $ 255,002 $ (34,989 ) $ 2,813,413 Equity securities Equity investments $ (31,875 ) $ 283,095 $ — $ — $ (31,875 ) $ 283,095 Emerging market debt funds — — (5,453 ) 56,421 (5,453 ) 56,421 Convertible funds (146 ) 46,185 — — (146 ) 46,185 Preferred equity investments (151 ) 7,361 — — (151 ) 7,361 Total equity securities $ (32,172 ) $ 336,641 $ (5,453 ) $ 56,421 $ (37,625 ) $ 393,062 (1) Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive (loss) income at December 31, 2015 .
Non-controlling Interests Rollforward	The following table summarizes the movements in the non-redeemable non-controlling interests balance from the acquisition date, July 31, 2015, to December 31, 2015 : Five Months Ended December 31, 2015 Non-controlling interests acquired July 31, 2015 $ 258,529 Income attributable to third-party investments in the BCGR Cell 5,526 Income attributable to third-party investments in BCRH 5,490 Net income attributable to non-controlling interests 11,016 Net third-party investments in BCRH 20 Dividends declared by BCRH attributable to non-controlling interests (1,755 ) Non-controlling interests - ending balance $ 267,810

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Schedule Of Fixed Maturity Investments, Equity Securities, Short-term Investments, Derivative Instruments and Debt Measured On A Recurring Basis	The following table sets forth the Company's fixed maturity investments, equity securities, short-term investments, other assets and liabilities and debt categorized by the level within the hierarchy in which the fair value measurements fall at December 31, 2014 : Fair Value Measurements at December 31, 2014 Total at December 31, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Fixed maturity investments U.S. government and agencies securities $ 587,411 $ 105,121 $ 482,290 $ — U.S. state and municipal securities 39,413 — 39,413 — Foreign government securities 240,536 — 240,536 — Government guaranteed corporate securities 48,102 — 48,102 — Corporate securities 1,361,462 — 1,358,960 2,502 Residential mortgage-backed securities 1,175,006 — 1,174,997 9 Commercial mortgage-backed securities 979,419 — 974,602 4,817 Collateralized loan and debt obligations 248,011 — 246,042 1,969 Asset-backed securities 413,221 — 410,228 2,993 Total fixed maturity investments $ 5,092,581 $ 105,121 $ 4,975,170 $ 12,290 Equity securities Equity investments 202,535 138,463 64,072 — Emerging market debt funds 60,150 — 60,150 — Convertible funds 46,111 — 46,111 — Preferred equity investments 15,836 — 15,836 — Short-term fixed income fund 6,736 6,736 — — Total equity securities $ 331,368 $ 145,199 $ 186,169 $ — Short-term investments 9,014 — 9,014 — Other assets (see Note 9) 99,504 — 73,889 25,615 Total assets $ 5,532,467 $ 250,320 $ 5,244,242 $ 37,905 Liabilities Other liabilities (see Note 9) $ 54,338 $ — $ 18,972 $ 35,366 Debt 623,740 — 623,740 — Total liabilities $ 678,078 $ — $ 642,712 $ 35,366 The following table sets forth the Company's fixed maturity investments, equity securities, short-term investments, other assets and liabilities and debt categorized by the level within the hierarchy in which the fair value measurements fall at December 31, 2015 : Fair Value Measurements at December 31, 2015 Total at December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Fixed maturity investments U.S. government and agencies securities $ 818,468 $ 37,741 $ 780,727 $ — U.S. state and municipal securities 22,406 — 22,406 — Foreign government securities 160,976 — 160,976 — Government guaranteed corporate securities 57,753 — 57,753 — Corporate securities 1,849,934 — 1,739,002 110,932 Residential mortgage-backed securities 1,311,373 — 1,311,373 — Commercial mortgage-backed securities 812,886 — 812,174 712 Collateralized loan and debt obligations 405,128 — 404,319 809 Asset-backed securities 507,255 — 507,255 — Total fixed maturity investments 5,946,179 37,741 5,795,985 112,453 Equity securities Equity investments 393,829 260,330 133,499 — Emerging market debt funds 56,421 — 56,421 — Convertible funds 46,185 — 46,185 — Preferred equity investments 17,623 — 17,623 — Short-term fixed income fund 14,756 14,756 — — Total equity securities 528,814 275,086 253,728 — Short-term investments 419,796 — 419,796 — Other assets (see Note 9) 68,892 4 27,385 41,503 Total assets $ 6,963,681 $ 312,831 $ 6,496,894 $ 153,956 Liabilities Other liabilities (see Note 9) $ 46,088 $ — $ 4,059 $ 42,029 Debt 737,974 — 737,974 — Total liabilities $ 784,062 $ — $ 742,033 $ 42,029
Fair Value Inputs Assets And Liabilities Quantitative Information [Table Text Block]	Below is a summary of quantitative information regarding the significant observable and unobservable inputs used in determining the fair value of the net weather and energy related derivative liabilities classified in Level 3 that are measured at fair value on a recurring basis at December 31, 2015 and 2014 : December 31, 2015 Fair Value (Level 3) Valuation Techniques Unobservable Inputs Low High Weighted Average or Actual (U.S. dollars in thousands, except for correlation) Net weather and energy related derivative liabilities $ 526 Historical Analysis and Simulation Correlation 0 1 Actual Weather curve $ (4,000 ) $ 10,600 Actual Commodity curve $ — $ 13 Actual December 31, 2014 Fair Value (Level 3) Valuation Techniques Unobservable Inputs Low High Weighted Average or Actual (U.S. dollars in thousands, except for correlation) Net weather and energy related derivative liabilities $ 9,751 Historical Analysis and Simulation Correlation 0 1 Actual Weather curve $ (828 ) $ 2,500 Actual Commodity curve $ — $ 13 Actual
Reconciliation Of The Beginning And Ending Balances For All Fixed Maturity Investments And Derivative Instruments Measured At Fair Value On A Recurring Basis Using Level 3 Inputs	The following tables present a reconciliation of the beginning and ending balances for all assets and liabilities measured at fair value on a recurring basis using Level 3 inputs during the years ended December 31, 2015 and 2014 . December 31, 2015 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of year $ 12,290 $ 25,615 $ 37,905 $ (35,366 ) Total equity income and realized and unrealized gains included in earnings 754 — 754 — Total equity losses and realized and unrealized losses included in earnings (3,539 ) — (3,539 ) — Total income included in other underwriting loss — 26,326 26,326 39,111 Total loss included in other underwriting loss — (29,277 ) (29,277 ) (34,049 ) Change in unrealized gains included in other comprehensive (loss) income 126 — 126 — Change in unrealized losses included in other comprehensive (loss) income (306 ) — (306 ) — Purchases 13 4,750 4,763 (4,231 ) Issues — 21,559 21,559 (34,114 ) Sales (15,695 ) — (15,695 ) — Settlements — (7,470 ) (7,470 ) 26,620 Transfers into Level 3 131,215 — 131,215 — Transfers out of Level 3 (12,405 ) — (12,405 ) — Level 3, end of year $ 112,453 $ 41,503 $ 153,956 $ (42,029 ) December 31, 2014 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of year $ 7,328 $ 14,038 $ 21,366 $ (19,569 ) Total equity income and realized gains included in earnings 144 — 144 — Total equity losses and losses included in earnings (85 ) — (85 ) — Total income included in other underwriting loss — 32,642 32,642 29,040 Total loss included in other underwriting loss — (27,147 ) (27,147 ) (37,617 ) Change in unrealized gains included in other comprehensive (loss) income 801 — 801 — Change in unrealized losses included in other comprehensive (loss) income (706 ) — (706 ) — Purchases 842 2,807 3,649 (1,404 ) Issues — 15,631 15,631 (23,197 ) Sales (1,848 ) — (1,848 ) (2,495 ) Settlements — (12,356 ) (12,356 ) 19,876 Transfers into Level 3 13,311 — 13,311 — Transfers out of Level 3 (7,497 ) — (7,497 ) — Level 3, end of year $ 12,290 $ 25,615 $ 37,905 $ (35,366 )

Reserve For Losses And Loss E45

Reserve For Losses And Loss Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Insurance Loss Reserves [Abstract]
Reserve For Losses And Loss Expenses	Activity in the reserve for losses and loss expenses for the years ended December 31, 2015 , 2014 and 2013 is summarized as follows: 2015 2014 2013 Gross reserve for losses and loss expenses, January 1 $ 3,846,859 $ 4,002,259 $ 4,240,876 Reinsurance recoverable on unpaid losses 670,795 593,755 691,783 Net reserve for losses and loss expenses, January 1 3,176,064 3,408,504 3,549,093 Incurred related to: Current year 1,160,572 1,203,977 1,442,076 Prior years (243,464 ) (233,815 ) (222,392 ) Total incurred 917,108 970,162 1,219,684 Paid related to: Current year (265,898 ) (439,169 ) (524,010 ) Prior years (867,739 ) (719,043 ) (838,082 ) Total paid (1,133,637 ) (1,158,212 ) (1,362,092 ) Amounts acquired (1) 675,019 — — Foreign currency translation and other (32,083 ) (44,390 ) 1,819 Net reserve for losses and loss expenses, December 31 3,602,471 3,176,064 3,408,504 Reinsurance recoverable on unpaid losses 907,944 670,795 593,755 Gross reserve for losses and loss expenses, December 31 $ 4,510,415 $ 3,846,859 $ 4,002,259

Reinsurance (Tables)

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2015
Reinsurance Disclosures [Abstract]
Effects Of Reinsurance On Premiums Written And Earned	The effects of reinsurance on premiums earned and written during the years ended December 31, 2015 , 2014 and 2013 are as follows: Year Ended December 31, 2015 Year Ended December 31, 2014 Year Ended December 31, 2013 Earned Written Earned Written Earned Written Direct $ 1,938,830 $ 2,085,901 $ 1,521,648 $ 1,716,128 $ 1,472,796 $ 1,475,429 Assumed 1,331,831 1,234,960 1,132,370 1,177,948 1,139,487 1,189,815 Ceded (1,292,208 ) (1,370,391 ) (790,040 ) (959,870 ) (595,799 ) (616,311 ) $ 1,978,453 $ 1,950,470 $ 1,863,978 $ 1,934,206 $ 2,016,484 $ 2,048,933
Losses Recoverable By Rating	The balance of reinsurance recoverable on paid and unpaid losses at December 31, 2015 and 2014 was distributed as follows based on the ratings of the reinsurers: Rating December 31, 2015 December 31, 2014 U.S. Government sponsored program $ 234,596 $ 339,617 A+ and above 458,255 294,216 A 476,184 248,297 A- 7,060 4 Not rated 19,875 6,952 Total $ 1,195,970 $ 889,086

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule Of The Fair Values And The Related Notional Values Of Derivatives Included In The Company's Consolidated Balance Sheet	The fair values and the related notional values of derivatives at December 31, 2015 and 2014 are noted below. December 31, 2015 December 31, 2014 Fair Value Notional Principal Amount Fair Value Notional Principal Amount Derivatives recorded in other assets Foreign exchange forward contracts $ 425 $ 38,818 $ 651 $ 42,694 Credit default swaps 36 4,225 — — Interest rate futures — — 7 7,595 TBAs 26,924 25,700 73,231 70,000 Energy and weather contracts 41,507 70,388 25,615 81,624 Total recorded in other assets $ 68,892 $ 99,504 Derivatives recorded in other liabilities Foreign exchange forward contracts $ 372 $ 30,400 $ 123 $ 20,945 Credit default swaps 276 7,800 — — Interest rate swaps 7 42,000 20 12,549 Interest rate swaptions — — 9 13,100 Interest rate futures 8 54,488 — — ILWs 259 19,500 — — LIBOR swap 233 100,000 — — TBAs — — 18,820 18,000 Loss development cover 2,904 22,322 — — Energy and weather contracts 42,029 148,325 35,366 135,050 Total recorded in other liabilities $ 46,088 $ 54,338 Net derivative asset $ 22,804 $ 45,166
Schedule Of The Gains And Losses On The Consolidated Statements Of Income And Comprehensive Income From Derivatives	The gains and losses on the Consolidated Statements of Income and Comprehensive Income for derivatives for the years ended December 31, 2015 , 2014 and 2013 were as follows: 2015 2014 2013 Total gain included in net foreign exchange losses from foreign exchange forward contracts $ 2,095 $ 1,880 $ 357 Interest rate futures 79 121 44 Credit default swaps (50 ) 30 49 Interest rate swaps (915 ) (4,239 ) 1,241 Interest rate swaptions 56 477 291 ILWs (326 ) — — LIBOR swap 332 — — TBAs 496 3,938 (958 ) Total (losses) gains included in net realized and unrealized gains (328 ) 327 667 Energy and weather contracts 2,281 (315 ) (261 ) Loss development cover (1,419 ) — — Total gain (loss) included in other underwriting loss 862 (315 ) (261 ) Total gains from derivatives $ 2,629 $ 1,892 $ 763

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Summary Of The Segment Revenues, Results And Reserve For Losses And Loss Expenses And The Carrying Value Of Goodwill	The following table provides a summary of the segment revenues and results for the year ended December 31, 2013 , reserve for losses and loss expenses as of December 31, 2013 and the carrying value of goodwill as of December 31, 2013 : Insurance Reinsurance Total Revenues Gross premiums written $ 1,475,429 $ 1,189,815 $ 2,665,244 Ceded premiums written (542,919 ) (73,392 ) (616,311 ) Net premiums written 932,510 1,116,423 2,048,933 Net premiums earned 946,474 1,070,010 2,016,484 Other underwriting loss — (2,046 ) (2,046 ) 946,474 1,067,964 2,014,438 Expenses Net losses and loss expenses 774,425 445,259 1,219,684 Acquisition expenses 64,778 239,652 304,430 General and administrative expenses 136,588 100,285 236,873 975,791 785,196 1,760,987 Underwriting (loss) income $ (29,317 ) $ 282,768 253,451 Net investment income 166,216 Corporate expenses (58,033 ) Net foreign exchange losses (14,214 ) Net realized and unrealized gains 15,164 Net impairment losses recognized in earnings (1,616 ) Amortization of intangibles (7,012 ) Interest expense (36,188 ) Income before income taxes $ 317,768 Net loss ratio 81.8 % 41.6 % 60.5 % Acquisition expense ratio 6.8 % 22.4 % 15.1 % General and administrative expense ratio 14.5 % 9.4 % 14.6 % (1) Combined ratio 103.1 % 73.4 % 90.2 % Reserve for losses and loss expenses $ 2,158,890 $ 1,843,369 $ 4,002,259 Goodwill $ 47,925 $ 43,368 $ 91,293 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. The following table provides a summary of the segment revenues and results for the year ended December 31, 2015 , reserve for losses and loss expenses as of December 31, 2015 and the carrying value of goodwill as of December 31, 2015 : Insurance Reinsurance Total Revenues Gross premiums written $ 2,085,901 $ 1,234,960 $ 3,320,861 Ceded premiums written (1,205,528 ) (164,863 ) (1,370,391 ) Net premiums written 880,373 1,070,097 1,950,470 Net premiums earned 824,552 1,153,901 1,978,453 Other underwriting loss — (3,694 ) (3,694 ) 824,552 1,150,207 1,974,759 Expenses Net losses and loss expenses 503,561 413,547 917,108 Acquisition expenses 80,252 267,633 347,885 General and administrative expenses 140,012 119,779 259,791 723,825 800,959 1,524,784 Underwriting income $ 100,727 $ 349,248 449,975 Net investment income 113,826 Corporate expenses (114,429 ) Net foreign exchange losses (26,964 ) Net realized and unrealized gains 12,660 Net impairment losses recognized in earnings (3,715 ) Amortization of intangibles (30,620 ) Interest expense (41,260 ) Income before income taxes $ 359,473 Net loss ratio 61.1 % 35.8 % 46.4 % Acquisition expense ratio 9.7 % 23.2 % 17.6 % General and administrative expense ratio 17.0 % 10.4 % 18.9 % (1) Combined ratio 87.8 % 69.4 % 82.9 % Reserve for losses and loss expenses $ 2,507,361 $ 2,003,054 $ 4,510,415 Goodwill $ 84,525 $ 91,930 $ 176,455 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. The following table provides a summary of the segment revenues and results for the year ended December 31, 2014 , reserve for losses and loss expenses as of December 31, 2014 and the carrying value of goodwill as of December 31, 2014 : Insurance Reinsurance Total Revenues Gross premiums written $ 1,716,128 $ 1,177,948 $ 2,894,076 Ceded premiums written (855,722 ) (104,148 ) (959,870 ) Net premiums written 860,406 1,073,800 1,934,206 Net premiums earned 833,912 1,030,066 1,863,978 Other underwriting loss — (5,786 ) (5,786 ) 833,912 1,024,280 1,858,192 Expenses Net losses and loss expenses 594,561 375,601 970,162 Acquisition expenses 65,368 254,145 319,513 General and administrative expenses 148,475 98,912 247,387 808,404 728,658 1,537,062 Underwriting income $ 25,508 $ 295,622 321,130 Net investment income 131,543 Corporate expenses (66,200 ) Net foreign exchange losses (3,839 ) Net realized and unrealized gains 14,283 Net impairment losses recognized in earnings (625 ) Amortization of intangibles (6,484 ) Interest expense (40,968 ) Income before income taxes $ 348,840 Net loss ratio 71.4 % 36.4 % 52.1 % Acquisition expense ratio 7.8 % 24.7 % 17.1 % General and administrative expense ratio 17.7 % 9.6 % 16.8 % (1) Combined ratio 96.9 % 70.7 % 86.0 % Reserve for losses and loss expenses $ 2,123,772 $ 1,723,087 $ 3,846,859 Goodwill $ 47,925 $ 43,313 $ 91,238 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses.
Schedule Of Gross Premiums Written By Line Of Business	The following table provides gross premiums written by line of business for the years ended December 31, 2015 , 2014 and 2013 : Business Segment 2015 2014 2013 Insurance Agriculture $ 840,445 $ 866,025 $ 954,389 Casualty and other specialty 514,203 396,113 303,803 Professional lines 344,482 263,538 148,537 Property, marine/energy and aviation 386,771 190,452 68,700 Total Insurance 2,085,901 1,716,128 1,475,429 Reinsurance Catastrophe 311,914 343,213 355,751 Property 209,392 287,326 297,806 Casualty 176,506 159,533 241,358 Professional lines 248,610 174,656 163,594 Specialty 288,538 213,220 131,306 Total Reinsurance 1,234,960 1,177,948 1,189,815 Total $ 3,320,861 $ 2,894,076 $ 2,665,244
Schedule Of Geographic Distribution Of Gross Premiums Written	The following table provides the geographic distribution of gross premiums written for the years ended December 31, 2015 , 2014 and 2013 : 2015 2014 2013 United States $ 2,305,301 $ 2,054,431 $ 1,960,693 Worldwide 566,664 456,078 435,655 Europe 209,729 172,077 153,516 Asia 75,165 38,442 23,349 Japan 58,524 45,618 33,879 Australasia 41,309 61,994 25,191 Other 64,169 65,436 32,961 Total $ 3,320,861 $ 2,894,076 $ 2,665,244

Goodwill And Intangible Asset49

Goodwill And Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule Of Goodwill And Intangible Assets	The following table shows an analysis of goodwill and intangible assets for the years ended December 31, 2015 and 2014 : Goodwill Intangible assets with indefinite lives Intangible assets with finite lives Total Net balance at December 31, 2013 $ 91,293 $ 17,229 $ 56,856 $ 165,378 Additions (55 ) — 16 (39 ) Amortization — — (6,484 ) (6,484 ) Impairment loss — (5,450 ) — $ (5,450 ) Net balance at December 31, 2014 $ 91,238 $ 11,779 $ 50,388 $ 153,405 Additions (1) 87,367 57,600 293,218 438,185 Amortization — — (30,620 ) (30,620 ) Foreign currency translation (2,150 ) — (4,860 ) (7,010 ) Net balance at December 31, 2015 $ 176,455 $ 69,379 $ 308,126 $ 553,960 Gross balance $ 178,605 $ 74,829 $ 431,260 $ 684,694 Accumulated amortization — — (118,274 ) (118,274 ) Accumulated impairment losses — (5,450 ) — (5,450 ) Accumulated foreign currency translation (2,150 ) — (4,860 ) (7,010 ) Net balance $ 176,455 $ 69,379 $ 308,126 $ 553,960

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule Of Percentage Of Gross Premiums Written Generated Through Company's Largest Brokers	The following table shows the percentage of gross premiums written generated through the Company's largest brokers for the years ended December 31, 2015 , 2014 and 2013 : Broker 2015 2014 2013 Marsh & McLennan Companies, Inc. 19.8 % 19.1 % 17.3 % Aon Benfield 12.8 % 13.2 % 15.6 % Willis Companies 9.2 % 10.6 % 9.9 % Total of largest brokers 41.8 % 42.9 % 42.8 %
Schedule Of Future Minimum Lease Commitments	Future minimum lease commitments at December 31, 2015 are as follows: Year ending December 31, Amount 2016 $ 15,375 2017 16,222 2018 15,716 2019 15,986 2020 14,408 2021 and thereafter 27,295 $ 105,002

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Schedule Of Company's Share Capital	The Company’s share capital at December 31, 2015 and 2014 is comprised as follows: 2015 2014 Preferred shares Authorized – $1.00 par value each 9,209,200 17,200,000 Issued, outstanding and fully paid: Series A preferred shares – $1.00 par value each; aggregate liquidation preference nil (2014 - $200,000) — 8,000,000 Series B preferred shares – $1.00 par value each; aggregate liquidation preference $230,000 (2014 - $230,000) 9,200,000 9,200,000 Series C preferred shares – $1.00 par value each; aggregate liquidation preference $230,000 (2014 - nil) 9,200 — 9,209,200 17,200,000 Common shares Authorized - $1.00 par value each 120,000,000 120,000,000 Issued, outstanding and fully paid: Ordinary common shares - $1.00 par value each 66,797,991 44,765,153
Schedule Of Accumulated Other Comprehensive (Loss) Income	The following table presents the changes in accumulated other comprehensive (loss) income balances by component for the years ended December 31, 2015 and 2014 : For the Year Ended December 31, 2015 Losses on cash flow hedges Unrealized (losses) gains on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,766 ) $ 86,100 $ (7,628 ) $ 76,706 Other comprehensive (loss) income before reclassifications — (65,941 ) (24,690 ) (90,631 ) Amounts reclassified from accumulated other comprehensive (loss) income (1) 88 (32,797 ) — (32,709 ) Net current period other comprehensive (loss) income 88 (98,738 ) (24,690 ) (123,340 ) Ending balance $ (1,678 ) $ (12,638 ) $ (32,318 ) $ (46,634 ) (1) All amounts are net of tax. For the Year Ended December 31, 2014 Losses on cash flow hedges Unrealized (losses) gains on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,855 ) $ 45,950 $ 18,636 $ 62,731 Other comprehensive (loss) income before reclassifications — 60,632 (26,264 ) 34,368 Amounts reclassified from accumulated other comprehensive (loss) income (1) 89 (20,482 ) — (20,393 ) Net current period other comprehensive (loss) income 89 40,150 (26,264 ) 13,975 Ending balance $ (1,766 ) $ 86,100 $ (7,628 ) $ 76,706 (1) All amounts are net of tax.
Reclassification Out Of Accumulated Other Comprehensive (Loss) Income	The following tables present the significant items reclassified out of accumulated other comprehensive (loss) income during the years ended December 31, 2015 and 2014 : For the Year Ended December 31, 2015 Details about accumulated other comprehensive (loss) income components Amount reclassified from accumulated other comprehensive (loss) income Affected line item in the Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 88 Interest expense 88 Total before income taxes — Income tax expense $ 88 Total net of income taxes Unrealized losses (gains) on available for sale securities $ (37,245 ) Net realized and unrealized gains 3,715 Net impairment losses recognized in earnings (33,530 ) Total before income taxes 733 Income tax expense $ (32,797 ) Total net of income taxes For the Year Ended December 31, 2014 Details about accumulated other comprehensive (loss) income components Amount reclassified from accumulated other comprehensive (loss) income Affected line item in the Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 89 Interest expense 89 Total before income taxes — Income tax expense $ 89 Total net of income taxes Unrealized losses (gains) on available for sale securities $ (19,406 ) Net realized and unrealized gains 625 Net impairment losses recognized in earnings (18,781 ) Total before income taxes (1,701 ) Income tax benefit $ (20,482 ) Total net of income taxes

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule Of Computation 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, 2015 , 2014 and 2013 : 2015 2014 2013 Numerator: Net income available to common and participating common shareholders $ 311,345 $ 315,700 $ 279,165 Less amount allocated to participating common shareholders (1) (8,749 ) (9,118 ) (6,444 ) Net income allocated to common shareholders $ 302,596 $ 306,582 $ 272,721 Denominator: Weighted average shares - basic 52,707,390 43,368,062 42,817,624 Share equivalents: Options 118,392 47,111 — Restricted shares and restricted share units 2,721 70 583 Weighted average shares - diluted 52,828,503 43,415,243 42,818,207 Basic earnings per common share $ 5.74 $ 7.07 $ 6.37 Diluted earnings per common share $ 5.73 $ 7.06 $ 6.37 (1) Represents earnings and dividends attributable to holders of unvested restricted shares and restricted share units issued under the Company's stock compensation plans that are considered participating. In periods of loss, no losses are allocated to participating common shareholders (unvested restricted shares and restricted share units).
Schedule Of Dividends Declared	The following table sets forth dividends declared in the years ended December 31, 2015 , 2014 and 2013 , respectively: 2015 2014 2013 Dividends declared per Series A preferred share $ 1.9375 $ 1.9375 $ 1.9375 Dividends declared per Series B preferred share $ 1.8750 $ 1.8750 $ 1.8750 Dividends declared per Series C preferred share $ — $ — $ — Dividends declared per common share $ 1.40 $ 1.36 $ 1.28

Stock-Based Employee Compensa53

Stock-Based Employee Compensation And Other Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary Of Stock Option Activity	A summary of option activity, including options held by employees, during the year ended December 31, 2015 is presented below: For the year ended December 31, 2015 Options Outstanding Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Aggregate Intrinsic Value Beginning of year 800,000 $ 48.20 Granted — — Exercised (480,000 ) 48.20 Forfeited — — Outstanding, end of year 320,000 $ 48.20 7.41 $ 5,053 Exercisable and vested options, end of year — $ — N/A $ —
Restricted Share And Restricted Share Unit Activity	A summary of the restricted share and restricted share unit activity during the year ended December 31, 2015 , is presented below: Number of Shares/Units Aggregate Intrinsic Value Unvested, beginning of year 1,290,894 Granted and assumed 1,388,179 Settled (997,068 ) Forfeited (18,423 ) Unvested, end of year 1,663,582 Outstanding, end of year 1,663,582 $ 106,453

Statutory Requirements And Di54

Statutory Requirements And Dividend Restrictions (Tables)	12 Months Ended
	Dec. 31, 2015
Statutory Requirements And Dividend Restrictions [Abstract]
Statutory Capital	(1) Bermuda statutory capital includes an investment in affiliate asset, which represents its interest in the remaining insurance and reinsurance operations of the Company included in the United States and U.K. columns above. (2) Bermuda includes the statutory capital of Endurance Bermuda and its foreign branches. (3) U.K. includes the statutory capital of Endurance U.K. The combined statutory capital and combined statutory net income (loss) for the Company's principal operating subsidiaries, excluding Syndicate 5151, in their respective jurisdictions were as follows: Statutory capital Bermuda (1)(2) United States U.K. (3) Singapore 2015 2014 2015 2014 2015 2014 2015 2014 Required statutory capital $ 1,276,453 $ 955,903 $ 281,905 $ 244,587 $ 84,086 $ 73,741 $ 3,524 $ 3,773 Actual statutory capital 4,307,249 2,876,927 768,791 702,513 538,265 555,283 49,842 32,272
Statutory Net Income (Loss)	Statutory net income (loss) Bermuda United States U.K. Singapore Year ended December 31, 2015 $ 417,298 $ 70,398 $ 969 $ 17,542 Year ended December 31, 2014 453,127 28,450 4,135 4,111 Year ended December 31, 2013 454,840 (48,035 ) 27,976 8,702

Taxes (Tables)

Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Tax Expense	The income tax expense was as follows for the years ended December 31, 2015 , 2014 and 2013 , respectively: 2015 2014 2013 Current income tax expense $ (6,262 ) $ (1,804 ) $ (3,089 ) Deferred income tax benefit (expense) 1,900 1,414 (2,764 ) Income tax expense $ (4,362 ) $ (390 ) $ (5,853 )
Schedule Of Effective Income Tax Rate Reconciliation	The actual income tax expense attributable to income for the years ended December 31, 2015 , 2014 and 2013 differed from the amount computed by applying the combined effective rate of 0% under Bermuda law to income before income taxes, as a result of the following: 2015 2014 2013 Computed expected tax expense $ — $ — $ — Tax (expense) benefit effect on foreign taxes (8,071 ) (1,661 ) 31,054 Change in valuation allowance 3,709 1,271 (36,907 ) $ (4,362 ) $ (390 ) $ (5,853 )
Schedule Of Net Deferred Tax Assets And Liabilities	Net deferred income tax assets and liabilities consisted of the following as of December 31, 2015 and 2014 : 2015 2014 Deferred income tax assets: Unearned premiums $ 25,172 $ 23,124 Loss reserves 27,370 29,410 Net operating loss carryforward 92,844 93,163 Deferred compensation 25,268 19,588 Deferred interest 46,568 44,951 Realized investment losses 4,972 125 Other 11,077 10,404 Total deferred income tax assets 233,271 220,765 Deferred income tax liabilities: Deferred acquisition costs (8,179 ) (10,843 ) Unrealized investment losses (gains) 1,568 (5,293 ) Unrealized foreign exchange gains (4,087 ) (2,704 ) Temporary differences related to acquisition (35,461 ) (20,344 ) Start up costs (1,565 ) (1,144 ) Other (7,561 ) (10,033 ) Total deferred income tax liabilities (55,285 ) (50,361 ) Valuation allowance (131,138 ) (121,409 ) Net deferred income tax asset $ 46,848 $ 48,995
Schedule Of Distribution Of Income Before Income Taxes	The Company's income before income taxes was distributed as follows for the years ended December 31, 2015 , 2014 and 2013 , respectively: 2015 2014 2013 U.S. (domestic) $ 95,649 $ 60,112 $ 13,103 Non-U.S. (foreign) (1) 263,824 288,728 304,665 Income before income taxes $ 359,473 $ 348,840 $ 317,768 (1) The Company's non-U.S. (foreign) operating subsidiaries write business that is exposed to risks originating in the United States.

Condensed Unaudited Quarterly56

Condensed Unaudited Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Summary Of The Unaudited Quarterly Data	The following is a summary of the unaudited quarterly data for the year ended December 31, 2015 : Quarter Ended Quarter Ended Quarter Ended Quarter Ended Net premiums earned $ 389,859 $ 458,135 $ 557,003 $ 573,456 Net investment income 41,861 32,252 16,533 23,180 Net realized and unrealized gains (losses) 18,189 9,680 5,029 (20,238 ) Net impairment losses recognized in earnings (649 ) (424 ) (38 ) (2,604 ) Subtotal $ 449,260 $ 499,643 $ 578,527 $ 573,794 Net losses and loss expenses $ 171,936 $ 239,122 $ 263,993 $ 242,057 Acquisition, general and administrative, and corporate expenses $ 149,251 $ 152,570 $ 225,558 $ 194,726 Net foreign exchange losses (gains) $ 7,552 $ 12,981 $ 8,621 $ (2,190 ) Net income $ 108,479 $ 84,206 $ 54,530 $ 107,896 Net income attributable to non-controlling interests — — (2,707 ) (8,309 ) Net income available to Endurance Holdings $ 108,479 $ 84,206 $ 51,823 $ 99,587 Preferred dividends (8,188 ) (8,188 ) (8,188 ) (8,186 ) Net income available to Endurance Holdings' common and participating common shareholders $ 100,291 $ 76,018 $ 43,635 $ 91,401 Basic earnings per share $ 2.24 $ 1.69 $ 0.73 $ 1.36 Diluted earnings per share $ 2.23 $ 1.68 $ 0.73 $ 1.36 The following is a summary of the unaudited quarterly data for the year ended December 31, 2014 : Quarter Ended Quarter Ended Quarter Ended Quarter Ended Net premiums earned $ 396,266 $ 481,538 $ 514,895 $ 471,279 Net investment income 40,990 39,302 25,357 25,894 Net realized and unrealized gains (losses) 4,872 3,411 9,788 (3,788 ) Net impairment losses recognized in earnings (111 ) (198 ) (102 ) (214 ) Subtotal $ 442,017 $ 524,053 $ 549,938 $ 493,171 Net losses and loss expenses $ 176,896 $ 259,196 $ 290,269 $ 243,801 Acquisition, general and administrative, and corporate expenses $ 145,363 $ 165,056 $ 174,307 $ 148,374 Net foreign exchange losses (gains) $ 2,964 $ 319 $ 783 $ (227 ) Net income $ 104,480 $ 83,163 $ 76,234 $ 84,573 Preferred dividends (8,188 ) (8,188 ) (8,188 ) (8,186 ) Net income available to Endurance Holdings' common and participating common shareholders $ 96,292 $ 74,975 $ 68,046 $ 76,387 Basic earnings per share $ 2.16 $ 1.68 $ 1.52 $ 1.71 Diluted earnings per share $ 2.16 $ 1.68 $ 1.52 $ 1.70

Organization (Narrative) (Detai

Organization (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015
Blue Capital Reinsurance Holdings [Member]
Noncontrolling Interest [Line Items]
Ownership percentage	33.30%
Blue Capital Global Reinsurance Fund [Member]
Noncontrolling Interest [Line Items]
Ownership percentage	25.10%

Summary Of Significant Accoun58

Summary Of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Significant Accounting Policies [Line Items]
Premiums Earned LO Duration	12 months
Premiums Earned Risk Attaching Duration	24 months
Allowance for estimated uncollectible premiums receivable	$ 7.4	$ 2.6
Vesting period for employee awards	4 years
Restricted share awards to non-employee directors, vesting period	1 year
Unamortized Debt Issuance Expenses	$ 3.2	$ 4.1	$ 5.1
High
Significant Accounting Policies [Line Items]
Cash equivalents maturity, in days	90 days
Short-term investments maturity, in days	1 year
Low
Significant Accounting Policies [Line Items]
Short-term investments maturity, in days	90 days

Acquisition of Montpelier (Narr

Acquisition of Montpelier (Narrative) (Details) $ / shares in Units, $ in Thousands	Jul. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Number of States in which Entity Operates	15
Total Company ordinary shares | shares	20,686,699
Total value of Company ordinary shares	$ 1,437,519
Special dividend paid per Montpelier common share and restricted share unit | $ / shares	$ 9.89
Acquisition transaction and integration related expenses		$ 76,600
Acquisition transaction costs		19,500
Integration related costs		4,400
Compensation related costs		$ 52,700
Measurement period for a business combination, in months		12 months
Montpelier [Member]
Business Acquisition [Line Items]
Total special dividend consideration paid to Montpelier common shareholders and Montpelier equity award holders	$ 451,101

Acquisition of Montpelier (Purc

Acquisition of Montpelier (Purchase Price) (Details) - USD ($) $ / shares in Units, $ in Thousands		Jul. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Number of Montpelier common shares outstanding immediately prior to the closing of the acquisition			66,797,991	44,765,153
Exchange ratio		0.472
Total Company ordinary shares		20,686,699
Company ordinary share closing price on July 31, 2015		$ 69.49
Total value of Company ordinary shares		$ 1,437,519
Fair value of restricted share units attributable to service period prior to Closing Date(1)	[1]	33,327
Total consideration		$ 1,470,846
Special dividend paid per Montpelier common share and restricted share unit		$ 9.89
Total consideration received by Montpelier common shareholders and Montpelier equity award holders		$ 1,921,947
Net purchase price		$ 1,470,846
Montpelier [Member]
Business Acquisition [Line Items]
Number of Montpelier common shares outstanding immediately prior to the closing of the acquisition		43,827,753
Number of Montpelier common shares and restricted share units eligible for special dividend		45,611,810
Total special dividend consideration paid to Montpelier common shareholders and Montpelier equity award holders		$ 451,101
[1]	Outstanding Montpelier restricted share units were assumed by the Company and adjusted as of the Closing Date to represent the right to receive 0.472 Company ordinary shares for each outstanding Montpelier restricted share unit rounded down to the next whole number of Company ordinary shares. The fair value of the Montpelier restricted share units was determined based on the closing price of the Company's ordinary shares on the Closing Date. The resulting fair value of the restricted share units was apportioned as purchase consideration based on service provided to Montpelier as of the Closing Date with the remaining fair value of these restricted share units to be recognized prospectively over the restricted share units' remaining vesting period.

Acquisition of Montpelier (Fair

Acquisition of Montpelier (Fair Value of Net Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Jul. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Montpelier shareholders' equity attributable to controlling interest prior to Special Dividend		$ 4,856,262	$ 3,185,182	$ 2,886,549
Fixed maturity investments, trading at fair value	$ (11,100)
Deferred acquisition costs	(91,713)
Reinsurance recoverable on unpaid losses	(675)
Other assets	(12,459)
Reserve for losses and loss expenses	10,822
Debt	21,123
Deferred tax liability	(18,346)
Non-controlling interest	25,615
Total adjustments for fair value by applicable balance sheet caption	$ (76,733)
Estimated total consideration over the fair value of net assets acquired assigned to goodwill		$ 176,455	$ 91,238	$ 91,293
Weighted average useful life of acquired finite-lived intangible assets	8 years
Total adjustments for fair value by applicable balance sheet caption and identifiable intangible assets	$ 274,067
Estimated fair value of net assets acquired and identifiable intangible assets	1,383,221
Total consideration paid by Endurance Holdings	1,470,846
Montpelier [Member]
Business Acquisition [Line Items]
Montpelier shareholders' equity attributable to controlling interest prior to Special Dividend	1,560,255
Cash and cash equivalents (Special Dividend on Montpelier common shares and Montpelier equity awards)	(451,101)
Adjusted shareholders' equity of Montpelier as of July 31, 2015	1,109,154
Identifiable finite lived intangible assets (non-contractual relationships, Lloyd's syndicate distribution channel, renewal rights, value of business acquired (VOBA), trade names, non-compete agreements and asset management agreements)	293,200
Estimated total consideration over the fair value of net assets acquired assigned to goodwill	87,625
Identifiable indefinite lived intangible assets (insurance licenses, Lloyd's syndicate capacity and asset management agreements)	$ 57,600

Acquisition of Montpelier (Inta

Acquisition of Montpelier (Intangible Assets) (Details) $ in Thousands	Jul. 31, 2015USD ($)
Business Acquisition [Line Items]
Identifiable intangible assets at July 31, 2015	$ 350,800
Key non-contractual relationships
Business Acquisition [Line Items]
Finite lived intangible assets acquired	$ 71,800
Finite-Lived Intangible Asset, Useful Life	10 years
Other non-contractual relationships
Business Acquisition [Line Items]
Finite lived intangible assets acquired	$ 22,400
Finite-Lived Intangible Asset, Useful Life	3 years
Trade names
Business Acquisition [Line Items]
Finite lived intangible assets acquired	$ 1,800
Insurance licenses
Business Acquisition [Line Items]
Indefinite lived intangible assets acquired	1,900
Non-compete agreements
Business Acquisition [Line Items]
Finite lived intangible assets acquired	5,700
Lloyd's syndicate capacity
Business Acquisition [Line Items]
Indefinite lived intangible assets acquired	48,300
Lloyd's syndicate distribution channel
Business Acquisition [Line Items]
Finite lived intangible assets acquired	$ 18,400
Finite-Lived Intangible Asset, Useful Life	10 years
Renewal rights
Business Acquisition [Line Items]
Finite lived intangible assets acquired	$ 82,100
Finite-Lived Intangible Asset, Useful Life	15 years
VOBA
Business Acquisition [Line Items]
Finite lived intangible assets acquired	$ 88,400
Finite-Lived Intangible Asset, Useful Life	2 years
Asset management agreements
Business Acquisition [Line Items]
Indefinite lived intangible assets acquired	$ 10,000

Acquisition of Montpelier (Fina

Acquisition of Montpelier (Financial Results) (Details) - USD ($) $ in Thousands		5 Months Ended	12 Months Ended
		Dec. 31, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Compensation related costs			$ 52,700
Montpelier [Member]
Business Acquisition [Line Items]
Total revenues		$ 225,899
Net income attributable to the Company's common shareholders(1)	[1]	$ 54,768
[1]	Includes $52.7 million of compensation-related costs associated with terminating employees of Montpelier.

Acquisition of Montpelier (Supp

Acquisition of Montpelier (Supplemental Proforma Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Business Combinations [Abstract]
Total revenues	$ 2,452,410	$ 2,668,604
Net income available to Endurance Holdings' common shareholders	$ 443,817	$ 388,371

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Sep. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Investments [Abstract]
Number of available for sale securities in an unrealized loss position	1,310				747				1,310	747
Number of securities in a continuous unrealized loss position for twelve months or greater	158				171				158	171
Unrealized losses	$ (72,600)				$ (19,900)				$ (72,600)	$ (19,900)
Unrealized losses, 12 months or greater	(12,700)				(7,100)				(12,700)	(7,100)
Net impairment losses recognized in earnings	$ 2,604	$ 38	$ 424	$ 649	$ 214	$ 102	$ 198	$ 111	$ 3,715	$ 625	$ 1,616

Investments (Composition Of Net

Investments (Composition Of Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Investment Income [Line Items]
Gross investment income									$ 130,312	$ 145,827	$ 180,147
Investment expenses									(16,486)	(14,284)	(13,931)
Net investment income	$ 23,180	$ 16,533	$ 32,252	$ 41,861	$ 25,894	$ 25,357	$ 39,302	$ 40,990	113,826	131,543	166,216
Total fixed income investments
Net Investment Income [Line Items]
Gross investment income									132,786	118,084	109,118
Equity securities
Net Investment Income [Line Items]
Gross investment income									8,209	5,689	3,956
Other investments
Net Investment Income [Line Items]
Gross investment income									(13,553)	19,609	64,321
Cash and Cash Equivalents [Member]
Net Investment Income [Line Items]
Gross investment income									$ 2,870	$ 2,445	$ 2,752

Investments (Contractual Maturi

Investments (Contractual Maturities Of Fixed Income Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale and Trading Securities [Line Items]
Due within one year, amortized cost	$ 622,070	$ 126,921
Due within one year, fair value	622,248	127,821
Due after one year through five years, amortized cost	2,005,456	1,627,154
Due after one year through five years, fair value	1,995,502	1,632,259
Due after five years through ten years, amortized cost	683,147	474,959
Due after five years through ten years, fair value	676,932	479,138
Due after ten years, amortized cost	33,168	43,314
Due after ten years, fair value	34,651	46,720
Residential mortgage-backed securities
Schedule of Available-for-sale and Trading Securities [Line Items]
No single maturity date, amortized cost	1,301,083	1,149,536
No single maturity date, fair value	1,311,373	1,175,006
Fixed income investments, fair value	1,311,373	1,175,006
Commercial mortgage-backed securities
Schedule of Available-for-sale and Trading Securities [Line Items]
No single maturity date, amortized cost	817,570	960,598
No single maturity date, fair value	812,886	979,419
Fixed income investments, fair value	812,886	979,419
Collateralized loan and debt obligations
Schedule of Available-for-sale and Trading Securities [Line Items]
No single maturity date, amortized cost	419,795	247,510
No single maturity date, fair value	405,128	248,011
Fixed income investments, fair value	405,128	248,011
Asset-backed securities
Schedule of Available-for-sale and Trading Securities [Line Items]
No single maturity date, amortized cost	510,540	411,529
No single maturity date, fair value	507,255	413,221
Fixed income investments, fair value	507,255	413,221
Total fixed income investments
Schedule of Available-for-sale and Trading Securities [Line Items]
Fixed income investments, amortized cost	6,392,829	5,041,521
Fixed income investments, fair value	$ 6,365,975	$ 5,101,595

Investments Investments (Fair V

Investments Investments (Fair Value of Trading Investments) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		$ 1,587,160	$ 0
Short-term investments, trading at fair value		394,111	0
Equity securities, trading at fair value		15,229	$ 0
U.S. government and agencies securities
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		319,674
U.S. state and municipal securities
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		5,559
Foreign government securities
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		49,861
Government guaranteed corporate securities
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		38,201
Corporate securities
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		532,192
Residential mortgage-backed securities
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		258,574
Commercial mortgage-backed securities
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		127,124
Collateralized loan and debt obligations
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value	[1]	103,219
Asset-backed securities
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		152,756
Total fixed maturity investments
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		1,587,160
Total fixed income investments
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		1,981,271
Equity investments
Schedule of Trading Securities [Line Items]
Equity securities, trading at fair value		48
Preferred equity investments
Schedule of Trading Securities [Line Items]
Equity securities, trading at fair value		553
Short-term fixed income fund
Schedule of Trading Securities [Line Items]
Equity securities, trading at fair value		14,628
Collateralized debt obligations
Schedule of Trading Securities [Line Items]
Fixed maturity investments, trading at fair value		$ 38,500
[1]	Balances include amounts related to collateralized debt obligations held with total fair values of $38.5 million at December 31, 2015.

Investments (Other Investments)

Investments (Other Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Market Value	$ 872,617	$ 541,454
Unfunded Commitments	132,070	70,542
Ineligible for redemption in next year	163,524	85,244
Alternative Funds [Member]
Schedule of Equity Method Investments [Line Items]
Market Value	809,121	485,944
Unfunded Commitments	132,070	70,542
Ineligible for redemption in next year	163,524	85,244
Hedge funds
Schedule of Equity Method Investments [Line Items]
Market Value	704,966	411,280
Unfunded Commitments	0	0
Ineligible for redemption in next year	57,876	10,580
Private investment funds
Schedule of Equity Method Investments [Line Items]
Market Value	80,690	74,664
Unfunded Commitments	102,070	70,542
Ineligible for redemption in next year	80,690	74,664
Other investment funds
Schedule of Equity Method Investments [Line Items]
Market Value	23,465
Unfunded Commitments	30,000
Ineligible for redemption in next year	24,958
Specialty Funds [Member]
Schedule of Equity Method Investments [Line Items]
Market Value	63,496	55,510
Unfunded Commitments	0	0
Ineligible for redemption in next year	0	0
High yield loan funds
Schedule of Equity Method Investments [Line Items]
Market Value	63,496	55,510
Unfunded Commitments	0	0
Ineligible for redemption in next year	$ 0	$ 0

Investments (Other Investments

Investments (Other Investments Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Other investments, invested amount	$ 737,100	$ 387,200
Market Value	872,617	541,454
Alternative Funds [Member]
Schedule of Equity Method Investments [Line Items]
Market Value	809,121	485,944
Hedge funds
Schedule of Equity Method Investments [Line Items]
Market Value	$ 704,966	411,280
Estimated liquidation, percentage in next 12 months	91.80%
Hedge funds | Low
Schedule of Equity Method Investments [Line Items]
Estimated notice period, in days	30 days
Hedge funds | High
Schedule of Equity Method Investments [Line Items]
Estimated notice period, in days	90 days
Private investment funds
Schedule of Equity Method Investments [Line Items]
Market Value	$ 80,690	74,664
Private investment funds | Low
Schedule of Equity Method Investments [Line Items]
Estimated liquidation period, in years	5 years
Private investment funds | High
Schedule of Equity Method Investments [Line Items]
Estimated liquidation period, in years	10 years
Specialty Funds [Member]
Schedule of Equity Method Investments [Line Items]
Market Value	$ 63,496	55,510
High yield loan funds
Schedule of Equity Method Investments [Line Items]
Market Value	$ 63,496	$ 55,510
High yield loan funds | Low
Schedule of Equity Method Investments [Line Items]
Estimated notice period, in days	30 days
High yield loan funds | High
Schedule of Equity Method Investments [Line Items]
Estimated notice period, in days	90 days

Investments (Net Realized And U

Investments (Net Realized And Unrealized Gains) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investments [Abstract]
Gross realized gains on investment sales										$ 65,881	$ 35,921	$ 40,018
Gross realized losses on investment sales										(28,636)	(16,515)	(25,521)
Net unrealized losses on trading securities										(24,257)	0	0
Intangible asset impairment loss	[1]									0	(5,450)	0
Change in fair value of derivative financial instruments	[2]									(328)	327	667
Net realized and unrealized gains		$ (20,238)	$ 5,029	$ 9,680	$ 18,189	$ (3,788)	$ 9,788	$ 3,411	$ 4,872	$ 12,660	$ 14,283	$ 15,164
[1]	For additional information on the Company's intangible assets, see Note 11, Goodwill and intangible assets.
[2]	For additional information on the Company's derivative financial instruments, see Note 9, Derivatives.

Investments (Amortized Cost, Fa

Investments (Amortized Cost, Fair Value And Unrealized Gains And Losses Classified As Available For Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2015		Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	$ 4,361,997		$ 5,032,506
Fixed income investments, fair value	4,359,019		5,092,581
Equity securities, cost	542,429		303,922
Equity securities, fair value	513,585		331,368
U.S. government and agencies securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	499,386		582,970
Fixed income investments, gross unrealized gains	2,561		6,471
Fixed income investments, gross unrealized losses	(3,153)		(2,030)
Fixed income investments, fair value	498,794		587,411
U.S. state and municipal securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	16,908		39,340
Fixed income investments, gross unrealized gains	120		191
Fixed income investments, gross unrealized losses	(181)		(118)
Fixed income investments, fair value	16,847		39,413
Foreign government securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	110,893		239,217
Fixed income investments, gross unrealized gains	803		2,983
Fixed income investments, gross unrealized losses	(581)		(1,664)
Fixed income investments, fair value	111,115		240,536
Government guaranteed corporate securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	19,248		47,436
Fixed income investments, gross unrealized gains	311		675
Fixed income investments, gross unrealized losses	(7)		(9)
Fixed income investments, fair value	19,552		48,102
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	1,323,276		1,354,370
Fixed income investments, gross unrealized gains	5,698		12,742
Fixed income investments, gross unrealized losses	(11,232)		(5,650)
Fixed income investments, fair value	1,317,742		1,361,462
Residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	1,041,540		1,149,536
Fixed income investments, gross unrealized gains	16,400		27,542
Fixed income investments, gross unrealized losses	(5,141)		(2,072)
Fixed income investments, fair value	1,052,799		1,175,006
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	689,078		960,598
Fixed income investments, gross unrealized gains	4,737		21,374
Fixed income investments, gross unrealized losses	(8,053)		(2,553)
Fixed income investments, fair value	685,762		979,419
Collateralized loan and debt obligations
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	304,915	[1]	247,510	[2]
Fixed income investments, gross unrealized gains	796	[1]	1,449	[2]
Fixed income investments, gross unrealized losses	(3,802)	[1]	(948)	[2]
Fixed income investments, fair value	301,909	[1]	248,011	[2]
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	356,753		411,529
Fixed income investments, gross unrealized gains	585		2,265
Fixed income investments, gross unrealized losses	(2,839)		(573)
Fixed income investments, fair value	354,499		413,221
Total fixed maturity investments
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	4,361,997		5,032,506
Fixed income investments, gross unrealized gains	32,011		75,692
Fixed income investments, gross unrealized losses	(34,989)		(15,617)
Fixed income investments, fair value	4,359,019		5,092,581
Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	25,657		9,015
Fixed income investments, gross unrealized gains	28		0
Fixed income investments, gross unrealized losses	0		(1)
Fixed income investments, fair value	25,685		9,014
Total fixed income investments
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	4,387,654		5,041,521
Fixed income investments, gross unrealized gains	32,039		75,692
Fixed income investments, gross unrealized losses	(34,989)		(15,618)
Fixed income investments, fair value	4,384,704		5,101,595
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	542,429		303,922
Equity securities, gross unrealized gains	8,781		31,682
Equity securities, gross unrealized loss	(37,625)		(4,236)
Equity securities, fair value	513,585		331,368
Equity investments
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	418,822		176,167
Equity securities, gross unrealized gains	6,834		29,660
Equity securities, gross unrealized loss	(31,875)		(3,292)
Equity securities, fair value	393,781		202,535
Emerging market debt funds
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	61,874		60,826
Equity securities, gross unrealized gains	0		0
Equity securities, gross unrealized loss	(5,453)		(676)
Equity securities, fair value	56,421		60,150
Convertible funds
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	46,331		46,331
Equity securities, gross unrealized gains	0		0
Equity securities, gross unrealized loss	(146)		(220)
Equity securities, fair value	46,185		46,111
Preferred equity investments
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	15,275		13,858
Equity securities, gross unrealized gains	1,946		2,022
Equity securities, gross unrealized loss	(151)		(44)
Equity securities, fair value	17,070		15,836
Short-term fixed income fund
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	127		6,740
Equity securities, gross unrealized gains	1		0
Equity securities, gross unrealized loss	0		(4)
Equity securities, fair value	128		6,736
Collateralized debt obligations
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, fair value	$ 11,400		$ 15,200
[1]	Balances include amounts related to collateralized debt obligations held with total fair values of $11.4 million.
[2]	Balances include amounts related to collateralized debt obligations held with total fair values of $15.2 million.

Investments (Available For Sale

Investments (Available For Sale Securities In An Unrealized Loss Position) (Details) - USD ($) $ in Thousands		Dec. 31, 2015		Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, 12 months or greater		$ (12,700)		$ (7,100)
Unrealized losses		(72,600)		(19,900)
U.S. government and agencies securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(2,175)	[1]	(481)	[2]
Fair value, less than 12 months		347,024		155,350
Unrealized losses, 12 months or greater		(978)	[1]	(1,549)	[2]
Fair value, 12 months or greater		16,669		45,993
Unrealized losses		(3,153)	[1]	(2,030)	[2]
Fair value		363,693		201,343
U.S. state and municipal securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(96)	[1]	(47)	[2]
Fair value, less than 12 months		9,662		3,295
Unrealized losses, 12 months or greater		(85)	[1]	(71)	[2]
Fair value, 12 months or greater		695		6,841
Unrealized losses		(181)	[1]	(118)	[2]
Fair value		10,357		10,136
Foreign government securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(404)	[1]	(1,378)	[2]
Fair value, less than 12 months		31,881		37,904
Unrealized losses, 12 months or greater		(177)	[1]	(286)	[2]
Fair value, 12 months or greater		3,966		4,306
Unrealized losses		(581)	[1]	(1,664)	[2]
Fair value		35,847		42,210
Government guaranteed corporate securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(7)	[1]	(9)	[2]
Fair value, less than 12 months		1,692		4,598
Unrealized losses, 12 months or greater		0	[1]	0	[2]
Fair value, 12 months or greater		0		0
Unrealized losses		(7)	[1]	(9)	[2]
Fair value		1,692		4,598
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(9,222)	[1]	(4,023)	[2]
Fair value, less than 12 months		830,349		533,139
Unrealized losses, 12 months or greater		(2,010)	[1]	(1,627)	[2]
Fair value, 12 months or greater		51,024		84,278
Unrealized losses		(11,232)	[1]	(5,650)	[2]
Fair value		881,373		617,417
Residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(3,378)	[1]	(260)	[2]
Fair value, less than 12 months		365,082		62,832
Unrealized losses, 12 months or greater		(1,763)	[1]	(1,812)	[2]
Fair value, 12 months or greater		79,355		108,899
Unrealized losses		(5,141)	[1]	(2,072)	[2]
Fair value		444,437		171,731
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(6,708)	[1]	(1,068)	[2]
Fair value, less than 12 months		436,387		180,222
Unrealized losses, 12 months or greater		(1,345)	[1]	(1,485)	[2]
Fair value, 12 months or greater		42,246		78,412
Unrealized losses		(8,053)	[1]	(2,553)	[2]
Fair value		478,633		258,634
Collateralized loan and debt obligations
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(3,107)	[1]	(876)	[2]
Fair value, less than 12 months		224,520		176,439
Unrealized losses, 12 months or greater		(695)	[1]	(72)	[2]
Fair value, 12 months or greater		48,167		6,491
Unrealized losses		(3,802)	[1]	(948)	[2]
Fair value		272,687		182,930
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(2,624)	[1]	(415)	[2]
Fair value, less than 12 months		311,814		199,205
Unrealized losses, 12 months or greater		(215)	[1]	(158)	[2]
Fair value, 12 months or greater		12,880		19,095
Unrealized losses		(2,839)	[1]	(573)	[2]
Fair value		324,694		218,300
Total fixed maturity investments
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	[2]			(8,557)
Fair value, less than 12 months				1,352,984
Unrealized losses, 12 months or greater	[2]			(7,060)
Fair value, 12 months or greater				354,315
Unrealized losses	[2]			(15,617)
Fair value				1,707,299
Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	[2]			(1)
Fair value, less than 12 months				1,953
Unrealized losses, 12 months or greater	[2]			0
Fair value, 12 months or greater				0
Unrealized losses	[2]			(1)
Fair value				1,953
Total fixed income investments
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(27,721)	[1]	(8,558)	[2]
Fair value, less than 12 months		2,558,411		1,354,937
Unrealized losses, 12 months or greater		(7,268)	[1]	(7,060)	[2]
Fair value, 12 months or greater		255,002		354,315
Unrealized losses		(34,989)	[1]	(15,618)	[2]
Fair value		2,813,413		1,709,252
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(32,172)	[1]	(4,236)	[2]
Fair value, less than 12 months		336,641		171,037
Unrealized losses, 12 months or greater		(5,453)	[1]	0	[2]
Fair value, 12 months or greater		56,421		0
Unrealized losses		(37,625)	[1]	(4,236)	[2]
Fair value		393,062		171,037
Equity investments
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(31,875)	[1]	(3,292)	[2]
Fair value, less than 12 months		283,095		53,591
Unrealized losses, 12 months or greater		0	[1]	0	[2]
Fair value, 12 months or greater		0		0
Unrealized losses		(31,875)	[1]	(3,292)	[2]
Fair value		283,095		53,591
Emerging market debt funds
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		0	[1]	(676)	[2]
Fair value, less than 12 months		0		60,150
Unrealized losses, 12 months or greater		(5,453)	[1]	0	[2]
Fair value, 12 months or greater		56,421		0
Unrealized losses		(5,453)	[1]	(676)	[2]
Fair value		56,421		60,150
Convertible funds
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(146)	[1]	(220)	[2]
Fair value, less than 12 months		46,185		46,111
Unrealized losses, 12 months or greater		0	[1]	0	[2]
Fair value, 12 months or greater		0		0
Unrealized losses		(146)	[1]	(220)	[2]
Fair value		46,185		46,111
Preferred equity investments
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(151)	[1]	(44)	[2]
Fair value, less than 12 months		7,361		4,449
Unrealized losses, 12 months or greater		0	[1]	0	[2]
Fair value, 12 months or greater		0		0
Unrealized losses		(151)	[1]	(44)	[2]
Fair value		$ 7,361		4,449
Short-term fixed income fund
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	[2]			(4)
Fair value, less than 12 months				6,736
Unrealized losses, 12 months or greater	[2]			0
Fair value, 12 months or greater				0
Unrealized losses	[2]			(4)
Fair value				$ 6,736
[1]	Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive (loss) income at December 31, 2015.
[2]	Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive (loss) income at December 31, 2014.

Investments Investments (Noncon

Investments Investments (Noncontrolling Interests Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended				5 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Noncontrolling Interest [Line Items]
Non-controlling interests acquired July 31, 2015				$ 0	$ 258,529	$ 0	$ 0
Net income attributable to non-controlling interests	$ 8,309	$ 2,707	$ 0	$ 0	11,016	11,016	0	$ 0
Non-controlling interests - ending balance	$ 267,810				267,810	$ 267,810	$ 0	$ 0
Blue Capital Reinsurance Holdings [Member]
Noncontrolling Interest [Line Items]
Net income attributable to non-controlling interests					5,490
Net third-party investments					20
Dividends declared by BCRH attributable to non-controlling interests					(1,755)
Ownership percentage						33.30%
Blue Capital Global Reinsurance Fund [Member]
Noncontrolling Interest [Line Items]
Net income attributable to non-controlling interests					$ 5,526
Ownership percentage						25.10%
Blue Capital Global Reinsurance Fund [Member] | High
Noncontrolling Interest [Line Items]
Ownership percentage						50.00%

Fair Value Measurement (Narrati

Fair Value Measurement (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Transfers into Level 3	$ 131,215	$ 13,311
Transfers out of Level 3	(12,405)	(7,497)
Amount of transfers from Level 1 to Level 2	$ 11,800	$ 6,600
Seven Percent Senior Notes [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Senior Notes, stated interest rate	7.00%
Four Point Seven Percent Senior Notes [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Senior Notes, stated interest rate	4.70%
Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Percentage of level 3 assets	2.20%	0.70%

Fair Value Measurement (Schedul

Fair Value Measurement (Schedule Of Available For Sale Investments, Other Assets And Liabilities, and Debt Measured On A Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 419,796	$ 9,014
Other assets (see Note 9)	68,892	99,504
Total assets	6,963,681	5,532,467
Other liabilities (see Note 9)	46,088	54,338
Debt	737,974	623,740
Total liabilities	784,062	678,078
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Other assets (see Note 9)	4	0
Total assets	312,831	250,320
Other liabilities (see Note 9)	0	0
Debt	0	0
Total liabilities	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	419,796	9,014
Other assets (see Note 9)	27,385	73,889
Total assets	6,496,894	5,244,242
Other liabilities (see Note 9)	4,059	18,972
Debt	737,974	623,740
Total liabilities	742,033	642,712
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Other assets (see Note 9)	41,503	25,615
Total assets	153,956	37,905
Other liabilities (see Note 9)	42,029	35,366
Debt	0	0
Total liabilities	42,029	35,366
U.S. government and agencies securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	818,468	587,411
U.S. government and agencies securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	37,741	105,121
U.S. government and agencies securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	780,727	482,290
U.S. government and agencies securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
U.S. state and municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	22,406	39,413
U.S. state and municipal securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
U.S. state and municipal securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	22,406	39,413
U.S. state and municipal securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Foreign government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	160,976	240,536
Foreign government securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Foreign government securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	160,976	240,536
Foreign government securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Government guaranteed corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	57,753	48,102
Government guaranteed corporate securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Government guaranteed corporate securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	57,753	48,102
Government guaranteed corporate securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	1,849,934	1,361,462
Corporate securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Corporate securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	1,739,002	1,358,960
Corporate securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	110,932	2,502
Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	1,311,373	1,175,006
Residential mortgage-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Residential mortgage-backed securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	1,311,373	1,174,997
Residential mortgage-backed securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	9
Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	812,886	979,419
Commercial mortgage-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Commercial mortgage-backed securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	812,174	974,602
Commercial mortgage-backed securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	712	4,817
Collateralized loan and debt obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	405,128	248,011
Collateralized loan and debt obligations | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Collateralized loan and debt obligations | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	404,319	246,042
Collateralized loan and debt obligations | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	809	1,969
Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	507,255	413,221
Asset-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	0
Asset-backed securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	507,255	410,228
Asset-backed securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	0	2,993
Total fixed maturity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	5,946,179	5,092,581
Total fixed maturity investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	37,741	105,121
Total fixed maturity investments | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	5,795,985	4,975,170
Total fixed maturity investments | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fixed maturity investments	112,453	12,290
Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	528,814	331,368
Equity securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	275,086	145,199
Equity securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	253,728	186,169
Equity securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	393,829	202,535
Equity investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	260,330	138,463
Equity investments | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	133,499	64,072
Equity investments | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Emerging market debt funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	56,421	60,150
Emerging market debt funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Emerging market debt funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	56,421	60,150
Emerging market debt funds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Convertible funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	46,185	46,111
Convertible funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Convertible funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	46,185	46,111
Convertible funds | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Preferred equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	17,623	15,836
Preferred equity investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Preferred equity investments | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	17,623	15,836
Preferred equity investments | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Short-term fixed income fund
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	14,756	6,736
Short-term fixed income fund | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	14,756	6,736
Short-term fixed income fund | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	0	0
Short-term fixed income fund | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total equity securities	$ 0	$ 0

Fair Value Measurement (Quantit

Fair Value Measurement (Quantitative Information Used As Level 3 Inputs) (Details)	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Net weather and energy related derivative liabilities	$ 22,804,000	$ 45,166,000
Derivatives recorded in other assets, fair value	68,892,000	99,504,000
Derivatives recorded in other liabilities, fair value	46,088,000	54,338,000
Significant Unobservable Inputs (Level 3)
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Derivatives recorded in other assets, fair value	41,503,000	25,615,000
Derivatives recorded in other liabilities, fair value	42,029,000	35,366,000
Energy Related Derivative [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Derivatives recorded in other assets, fair value	41,507,000	25,615,000
Derivatives recorded in other liabilities, fair value	42,029,000	35,366,000
Energy Related Derivative [Member] | Significant Unobservable Inputs (Level 3)
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Net weather and energy related derivative liabilities	$ 526,000	$ 9,751,000
Energy Related Derivative [Member] | Significant Unobservable Inputs (Level 3) | Valuation Techniques | High
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Correlation	1	1
Weather curve	$ 10,600,000	$ 2,500,000
Commodity curve	$ 13,000	$ 13,000
Energy Related Derivative [Member] | Significant Unobservable Inputs (Level 3) | Valuation Techniques | Low
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Correlation	0	0
Weather curve	$ (4,000,000)	$ (828,000)
Commodity curve	$ 0	$ 0

Fair Value Measurement (Reconci

Fair Value Measurement (Reconciliation Of The Beginning And Ending Balances For All Fixed Maturity Investments Measured At Fair Value On A Recurring Basis Using Level 3) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3, beginning of year	$ 37,905	$ 21,366
Total equity income and realized and unrealized gains included in earnings	754	144
Total equity losses and realized and unrealized losses included in earnings	(3,539)	(85)
Total income included in other underwriting loss	26,326	32,642
Total loss included in other underwriting loss	(29,277)	(27,147)
Change in unrealized gains included in other comprehensive (loss) income	126	801
Change in unrealized losses included in other comprehensive (loss) income	(306)	(706)
Purchases	4,763	3,649
Issues	21,559	15,631
Sales	(15,695)	(1,848)
Settlements	(7,470)	(12,356)
Transfers into Level 3	131,215	13,311
Transfers out of Level 3	(12,405)	(7,497)
Level 3, end of year	153,956	37,905
Fixed maturity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3, beginning of year	12,290	7,328
Total equity income and realized and unrealized gains included in earnings	754	144
Total equity losses and realized and unrealized losses included in earnings	(3,539)	(85)
Total income included in other underwriting loss	0	0
Total loss included in other underwriting loss	0	0
Change in unrealized gains included in other comprehensive (loss) income	126	801
Change in unrealized losses included in other comprehensive (loss) income	(306)	(706)
Purchases	13	842
Issues	0	0
Sales	(15,695)	(1,848)
Settlements	0	0
Transfers into Level 3	131,215	13,311
Transfers out of Level 3	(12,405)	(7,497)
Level 3, end of year	112,453	12,290
Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3, beginning of year	25,615	14,038
Total equity income and realized and unrealized gains included in earnings	0	0
Total equity losses and realized and unrealized losses included in earnings	0	0
Total income included in other underwriting loss	26,326	32,642
Total loss included in other underwriting loss	(29,277)	(27,147)
Change in unrealized gains included in other comprehensive (loss) income	0	0
Change in unrealized losses included in other comprehensive (loss) income	0	0
Purchases	4,750	2,807
Issues	21,559	15,631
Sales	0	0
Settlements	(7,470)	(12,356)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Level 3, end of year	41,503	25,615
Other liabilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3, beginning of year	(35,366)	(19,569)
Total equity income and realized and unrealized gains included in earnings	0	0
Total equity losses and realized and unrealized losses included in earnings	0	0
Total income included in other underwriting loss	39,111	29,040
Total loss included in other underwriting loss	(34,049)	(37,617)
Change in unrealized gains included in other comprehensive (loss) income	0	0
Change in unrealized losses included in other comprehensive (loss) income	0	0
Purchases	(4,231)	(1,404)
Issues	(34,114)	(23,197)
Sales	0	(2,495)
Settlements	26,620	19,876
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Level 3, end of year	$ (42,029)	$ (35,366)

Reserve For Losses And Loss E79

Reserve For Losses And Loss Expenses (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred related to Prior years	$ (243,464)	$ (233,815)	$ (222,392)
Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred related to Prior years	161,500	153,200	188,500
Insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred related to Prior years	$ 82,000	$ 80,600	$ 33,900

Reserve For Losses And Loss E80

Reserve For Losses And Loss Expenses (Reserve For Losses And Loss Expenses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Insurance Loss Reserves [Abstract]
Gross reserve for losses and loss expenses, January 1	$ 3,846,859	$ 4,002,259	$ 4,240,876
Reinsurance recoverable on unpaid losses	670,795	593,755	691,783
Net reserve for losses and loss expenses, January 1	3,176,064	3,408,504	3,549,093
Incurred related to Current year	1,160,572	1,203,977	1,442,076
Incurred related to Prior years	(243,464)	(233,815)	(222,392)
Total incurred	917,108	970,162	1,219,684
Paid related to Current year	(265,898)	(439,169)	(524,010)
Paid related to Prior years	(867,739)	(719,043)	(838,082)
Total paid	(1,133,637)	(1,158,212)	(1,362,092)
Amounts acquired(1)	675,019	0	0
Foreign currency translation and other	(32,083)	(44,390)	1,819
Net reserve for losses and loss expenses, December 31	3,602,471	3,176,064	3,408,504
Reinsurance recoverable on unpaid losses	907,944	670,795	593,755
Gross reserve for losses and loss expenses, December 31	$ 4,510,415	$ 3,846,859	$ 4,002,259

Reinsurance (Narrative) (Detail

Reinsurance (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance Disclosures [Abstract]
Ceded losses	$ 833.7	$ 575.7	$ 683.2

Reinsurance (Effects Of Reinsur

Reinsurance (Effects Of Reinsurance On Premiums Earned And Written) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance Disclosures [Abstract]
Direct premiums earned									$ 1,938,830	$ 1,521,648	$ 1,472,796
Assumed premiums earned									1,331,831	1,132,370	1,139,487
Ceded premiums earned									(1,292,208)	(790,040)	(595,799)
Net premiums earned	$ 573,456	$ 557,003	$ 458,135	$ 389,859	$ 471,279	$ 514,895	$ 481,538	$ 396,266	1,978,453	1,863,978	2,016,484
Direct premiums written									2,085,901	1,716,128	1,475,429
Assumed premiums written									1,234,960	1,177,948	1,189,815
Ceded premiums written									(1,370,391)	(959,870)	(616,311)
Net premiums written									$ 1,950,470	$ 1,934,206	$ 2,048,933

Reinsurance (Losses Recoverable

Reinsurance (Losses Recoverable On Paid And Unpaid Losses By Rating) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	$ 1,195,970	$ 889,086
Collateralized [Member]
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	321,500	199,700
U.S. Government sponsored program
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	234,596	339,617
A plus and above
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	458,255	294,216
A
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	476,184	248,297
A-
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	7,060	4
Not rated
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	$ 19,875	$ 6,952

Debt And Financing Arrangemen84

Debt And Financing Arrangements (Credit Facility) (Details) - USD ($) $ in Thousands	Apr. 19, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	May. 08, 2007
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 700,000				$ 1,175,000
Amount outstanding under credit facility		$ 0	$ 0
Amount of letters of credit outstanding		341,600	209,900
Increase to credit facility		350,000
Consolidated tangible net worth required		1,800,000
Aggregate interest payments		$ 40,500	40,400	$ 35,700
High
Line of Credit Facility [Line Items]
Leverage ratio		35.00%
Tranche 1 [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 560,000
Line of credit facility collateralized LOC fee	0.45%
Tranche 2 [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 140,000
Interest rate spread on federal funds rate	0.50%
Tranche 2 [Member] | Low
Line of Credit Facility [Line Items]
Line of credit facility uncollateralized LOC fee	1.125%
Tranche 2 [Member] | High
Line of Credit Facility [Line Items]
Line of credit facility uncollateralized LOC fee	1.75%
Tranche 2 [Member] | Eurodollar [Member]
Line of Credit Facility [Line Items]
Increase in interest rate on revolving loans	1.00%
Tranche 2 [Member] | Eurodollar [Member] | Low
Line of Credit Facility [Line Items]
Increase in interest rate on revolving loans	0.125%
Tranche 2 [Member] | Eurodollar [Member] | High
Line of Credit Facility [Line Items]
Increase in interest rate on revolving loans	0.75%
Tranche 2 [Member] | LIBOR [Member] | Low
Line of Credit Facility [Line Items]
Increase in interest rate on revolving loans	1.125%
Tranche 2 [Member] | LIBOR [Member] | High
Line of Credit Facility [Line Items]
Increase in interest rate on revolving loans	1.75%
Credit Facility [Member]
Line of Credit Facility [Line Items]
Term of facility	4 years
Amount of letters of credit outstanding		$ 329,900	204,000
LOC Agreements [Member]
Line of Credit Facility [Line Items]
Amount of letters of credit outstanding		$ 11,700	$ 5,900
LOC Agreements [Member] | Low
Line of Credit Facility [Line Items]
Line Of Credit Facility Used Capacity Commitment Fee Percentage		0.30%
LOC Agreements [Member] | High
Line of Credit Facility [Line Items]
Line Of Credit Facility Used Capacity Commitment Fee Percentage		0.45%
Trust Preferred Securities [Member]
Line of Credit Facility [Line Items]
Interest rate spread on federal funds rate		3.80%

Debt And Financing Arrangemen85

Debt And Financing Arrangements (Senior Notes and Trust Preferred Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Aggregate interest payments	$ 40.5	$ 40.4	$ 35.7
LIBOR swap
Debt Instrument [Line Items]
Stated interest rate	4.905%
Term of LIBOR swap	5 years
Seven Percent Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount	$ 335
Stated interest rate	7.00%
Six Point One Five Percent Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount	$ 200
Stated interest rate	6.15%
Four Point Seven Percent Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount	$ 300
Stated interest rate	4.70%
Trust Preferred Securities [Member]
Debt Instrument [Line Items]
Principal amount	$ 100
Debt Instrument, Description of Variable Rate Basis	3-month
Interest rate spread on LIBOR rate	3.80%
Debt Instrument, Redemption Price, Percentage	100.00%
LIBOR swap
Debt Instrument [Line Items]
Term of LIBOR swap	5 years

Debt And Financing Arrangemen86

Debt And Financing Arrangements (Credit Agreements) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Apr. 19, 2012	May. 08, 2007
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 700	$ 1,175
Blue Capital Reinsurance Holdings [Member]
Line of Credit Facility [Line Items]
Term of facility	364 days
Maximum borrowing capacity	$ 20
Annual guarantee fee percentage	0.125%
Short-term Debt	$ 13
Debt Covenant Debt To Total Capitalization Required	22.50%
Debt Covenant Minimum Net Worth To Maintain	70.00%
Blue Capital Reinsurance Holdings [Member] | Due February 2 2016 [Member]
Line of Credit Facility [Line Items]
Future repayments of lines of credit	$ 4
Annual interest rate	1.33%
Blue Capital Reinsurance Holdings [Member] | Due February 22 2016 [Member]
Line of Credit Facility [Line Items]
Future repayments of lines of credit	$ 5
Annual interest rate	1.48%
Blue Capital Reinsurance Holdings [Member] | Due March 11 2016 [Member]
Line of Credit Facility [Line Items]
Future repayments of lines of credit	$ 4
Annual interest rate	1.51%
Blue Capital Global Reinsurance Fund [Member]
Line of Credit Facility [Line Items]
Term of facility	364 days
Maximum borrowing capacity	$ 20
Annual guarantee fee percentage	0.125%
Short-term Debt	$ 6
Blue Capital Global Reinsurance Fund [Member] | Due February 1, 2016 [Member]
Line of Credit Facility [Line Items]
Future repayments of lines of credit	$ 3
Annual interest rate	1.54%
Blue Capital Global Reinsurance Fund [Member] | Due February 12, 2016 [Member]
Line of Credit Facility [Line Items]
Future repayments of lines of credit	$ 3
Annual interest rate	1.51%

Derivatives (Narrative) (Detail

Derivatives (Narrative) (Details) - Cash Flow Hedging [Member] $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Senior Notes, stated interest rate	7.00%
Notional amount	$ 125
Percentage of protection	50.00%
U.S. treasury benchmark in years	30 years
Payment for interest rate lock derivative	$ 2.7

Derivatives (Schedule Of The Fa

Derivatives (Schedule Of The Fair Values And The Related Notional Values Of Derivatives Included In The Company's Consolidated Balance Sheet) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	$ 68,892	$ 99,504
Derivatives recorded in other liabilities, fair value	46,088	54,338
Net derivative asset	22,804	45,166
Derivative assets traded under master netting agreements	68,900	99,500
Derivative liabilities traded under master netting agreements	46,100	54,300
Securities for Reverse Repurchase Agreements	$ 30,000	0
Low
Derivatives, Fair Value [Line Items]
Required Collateral Percentage	102.00%
Foreign exchange forward contracts
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	$ 425	651
Derivatives recorded in other liabilities, fair value	372	123
Derivative recorded in other assets, notional principal amount	38,818	42,694
Derivative recorded in other liabilities, notional principal amount	30,400	20,945
Credit default swaps
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	36	0
Derivatives recorded in other liabilities, fair value	276	0
Derivative recorded in other assets, notional principal amount	4,225	0
Derivative recorded in other liabilities, notional principal amount	$ 7,800	0
Credit default swaps | High
Derivatives, Fair Value [Line Items]
Original term of credit default swap, in years	5 years
Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	$ 7	20
Derivative recorded in other liabilities, notional principal amount	42,000	12,549
Interest rate swaptions
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	0	9
Derivative recorded in other liabilities, notional principal amount	0	13,100
Interest rate futures
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	0	7
Derivatives recorded in other liabilities, fair value	8	0
Derivative recorded in other assets, notional principal amount	0	7,595
Derivative recorded in other liabilities, notional principal amount	54,488	0
ILWs
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	259	0
Derivative recorded in other liabilities, notional principal amount	19,500	0
LIBOR swap
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	233	0
Derivative recorded in other liabilities, notional principal amount	$ 100,000	0
Term of LIBOR swap	5 years
Stated interest rate	4.905%
TBAs
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	$ 26,924	73,231
Derivatives recorded in other liabilities, fair value	0	18,820
Derivative recorded in other assets, notional principal amount	25,700	70,000
Derivative recorded in other liabilities, notional principal amount	0	18,000
Loss development cover
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	2,904	0
Derivative recorded in other liabilities, notional principal amount	22,322	0
Energy and weather contracts
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	41,507	25,615
Derivatives recorded in other liabilities, fair value	42,029	35,366
Derivative recorded in other assets, notional principal amount	70,388	81,624
Derivative recorded in other liabilities, notional principal amount	$ 148,325	$ 135,050

Derivatives (Schedule Of The Ga

Derivatives (Schedule Of The Gains And Losses On Derivative Instruments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	$ (328)	$ 327	$ 667
Total gain (loss) included in other underwriting loss	862	(315)	(261)
Total gains from derivatives	2,629	1,892	763
Foreign exchange forward contracts
Derivative [Line Items]
Total gain included in net foreign exchange losses from foreign exchange forward contracts	2,095	1,880	357
Interest rate futures
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	79	121	44
Credit default swaps
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	(50)	30	49
Interest rate swaps
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	(915)	(4,239)	1,241
Interest rate swaptions
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	56	477	291
ILWs
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	(326)	0	0
LIBOR swap
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	332	0	0
TBAs
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	496	3,938	(958)
Energy and weather contracts
Derivative [Line Items]
Total gain (loss) included in other underwriting loss	2,281	(315)	(261)
Loss development cover
Derivative [Line Items]
Total gain (loss) included in other underwriting loss	$ (1,419)	$ 0	$ 0

Segment Reporting (Summary Of T

Segment Reporting (Summary Of The Segment Revenues, Results And Reserve For Losses And Loss Expenses And Carrying Value Of Goodwill) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Gross premiums written										$ 3,320,861	$ 2,894,076	$ 2,665,244
Ceded premiums written										(1,370,391)	(959,870)	(616,311)
Net premiums written										1,950,470	1,934,206	2,048,933
Net premiums earned		$ 573,456	$ 557,003	$ 458,135	$ 389,859	$ 471,279	$ 514,895	$ 481,538	$ 396,266	1,978,453	1,863,978	2,016,484
Other underwriting loss										(3,694)	(5,786)	(2,046)
Total revenue										1,974,759	1,858,192	2,014,438
Net losses and loss expenses		242,057	263,993	239,122	171,936	243,801	290,269	259,196	176,896	917,108	970,162	1,219,684
Acquisition expenses										347,885	319,513	304,430
General and administrative expenses										259,791	247,387	236,873
Total expenses										1,524,784	1,537,062	1,760,987
Underwriting income										449,975	321,130	253,451
Net investment income		23,180	16,533	32,252	41,861	25,894	25,357	39,302	40,990	113,826	131,543	166,216
Corporate expenses										(114,429)	(66,200)	(58,033)
Net foreign exchange losses		2,190	(8,621)	(12,981)	(7,552)	227	(783)	(319)	(2,964)	(26,964)	(3,839)	(14,214)
Net realized and unrealized gains		(20,238)	5,029	9,680	18,189	(3,788)	9,788	3,411	4,872	12,660	14,283	15,164
Net impairment losses recognized in earnings		(2,604)	$ (38)	$ (424)	$ (649)	(214)	$ (102)	$ (198)	$ (111)	(3,715)	(625)	(1,616)
Amortization of intangibles										(30,620)	(6,484)	(7,012)
Interest expense										(41,260)	(40,968)	(36,188)
Income before income taxes										$ 359,473	$ 348,840	$ 317,768
Net loss ratio										46.40%	52.10%	60.50%
Acquisition expense ratio										17.60%	17.10%	15.10%
General and administrative expense ratio	[1]									18.90%	16.80%	14.60%
Combined ratio										82.90%	86.00%	90.20%
Reserve for losses and loss expenses		4,510,415				3,846,859				$ 4,510,415	$ 3,846,859	$ 4,002,259	$ 4,240,876
Goodwill		176,455				91,238				176,455	91,238	91,293
Insurance
Segment Reporting Information [Line Items]
Gross premiums written										2,085,901	1,716,128	1,475,429
Ceded premiums written										(1,205,528)	(855,722)	(542,919)
Net premiums written										880,373	860,406	932,510
Net premiums earned										824,552	833,912	946,474
Other underwriting loss										0	0	0
Total revenue										824,552	833,912	946,474
Net losses and loss expenses										503,561	594,561	774,425
Acquisition expenses										80,252	65,368	64,778
General and administrative expenses										140,012	148,475	136,588
Total expenses										723,825	808,404	975,791
Underwriting income										$ 100,727	$ 25,508	$ (29,317)
Net loss ratio										61.10%	71.40%	81.80%
Acquisition expense ratio										9.70%	7.80%	6.80%
General and administrative expense ratio	[1]									17.00%	17.70%	14.50%
Combined ratio										87.80%	96.90%	103.10%
Reserve for losses and loss expenses		2,507,361				2,123,772				$ 2,507,361	$ 2,123,772	$ 2,158,890
Goodwill		84,525				47,925				84,525	47,925	47,925
Reinsurance
Segment Reporting Information [Line Items]
Gross premiums written										1,234,960	1,177,948	1,189,815
Ceded premiums written										(164,863)	(104,148)	(73,392)
Net premiums written										1,070,097	1,073,800	1,116,423
Net premiums earned										1,153,901	1,030,066	1,070,010
Other underwriting loss										(3,694)	(5,786)	(2,046)
Total revenue										1,150,207	1,024,280	1,067,964
Net losses and loss expenses										413,547	375,601	445,259
Acquisition expenses										267,633	254,145	239,652
General and administrative expenses										119,779	98,912	100,285
Total expenses										800,959	728,658	785,196
Underwriting income										$ 349,248	$ 295,622	$ 282,768
Net loss ratio										35.80%	36.40%	41.60%
Acquisition expense ratio										23.20%	24.70%	22.40%
General and administrative expense ratio	[1]									10.40%	9.60%	9.40%
Combined ratio										69.40%	70.70%	73.40%
Reserve for losses and loss expenses		2,003,054				1,723,087				$ 2,003,054	$ 1,723,087	$ 1,843,369
Goodwill		$ 91,930				$ 43,313				$ 91,930	$ 43,313	$ 43,368
[1]	Total general and administrative expense ratio includes general and administrative expenses and corporate expenses.

Segment Reporting (Schedule Of

Segment Reporting (Schedule Of Gross Premiums Written By Line Of Business) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue, Major Customer [Line Items]
Gross premiums written	$ 3,320,861	$ 2,894,076	$ 2,665,244
Insurance
Revenue, Major Customer [Line Items]
Gross premiums written	2,085,901	1,716,128	1,475,429
Agriculture
Revenue, Major Customer [Line Items]
Gross premiums written	840,445	866,025	954,389
Casualty and other specialty
Revenue, Major Customer [Line Items]
Gross premiums written	514,203	396,113	303,803
Professional lines
Revenue, Major Customer [Line Items]
Gross premiums written	344,482	263,538	148,537
Property, marine/energy and aviation
Revenue, Major Customer [Line Items]
Gross premiums written	386,771	190,452	68,700
Reinsurance
Revenue, Major Customer [Line Items]
Gross premiums written	1,234,960	1,177,948	1,189,815
Catastrophe
Revenue, Major Customer [Line Items]
Gross premiums written	311,914	343,213	355,751
Property
Revenue, Major Customer [Line Items]
Gross premiums written	209,392	287,326	297,806
Casualty
Revenue, Major Customer [Line Items]
Gross premiums written	176,506	159,533	241,358
Professional lines
Revenue, Major Customer [Line Items]
Gross premiums written	248,610	174,656	163,594
Specialty
Revenue, Major Customer [Line Items]
Gross premiums written	$ 288,538	$ 213,220	$ 131,306

Segment Reporting (Schedule O92

Segment Reporting (Schedule Of Geographic Distribution Of Gross Premiums Written) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Geographic Distribution Of Gross Premiums Category [Line Items]
Gross premiums written	$ 3,320,861	$ 2,894,076	$ 2,665,244
United States
Geographic Distribution Of Gross Premiums Category [Line Items]
Gross premiums written	2,305,301	2,054,431	1,960,693
Worldwide
Geographic Distribution Of Gross Premiums Category [Line Items]
Gross premiums written	566,664	456,078	435,655
Europe
Geographic Distribution Of Gross Premiums Category [Line Items]
Gross premiums written	209,729	172,077	153,516
Asia
Geographic Distribution Of Gross Premiums Category [Line Items]
Gross premiums written	75,165	38,442	23,349
Japan
Geographic Distribution Of Gross Premiums Category [Line Items]
Gross premiums written	58,524	45,618	33,879
Australasia
Geographic Distribution Of Gross Premiums Category [Line Items]
Gross premiums written	41,309	61,994	25,191
Other
Geographic Distribution Of Gross Premiums Category [Line Items]
Gross premiums written	$ 64,169	$ 65,436	$ 32,961

Goodwill And Intangible Asset93

Goodwill And Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Impairment Loss		$ 0	$ 0
Intangible asset impairment loss	[1]	0	$ (5,450)	$ 0
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of intangible assets with finite lives, 2016		85,500
Amortization of intangible assets with finite lives, 2017		64,400
Amortization of intangible assets with finite lives, 2018		38,000
Amortization of intangible assets with finite lives, 2019		27,700
Amortization of intangible assets with finite lives, 2020		22,900
Amortization of intangible assets with finite lives, after 2020		$ 74,500
[1]	For additional information on the Company's intangible assets, see Note 11, Goodwill and intangible assets.

Goodwill And Intangible Asset94

Goodwill And Intangible Assets (Schedule Of Goodwill And Intangible Assets) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Schedule Of Goodwill And Intangible Assets [Line Items]
Net beginning balance		$ 153,405		$ 165,378
Additions		438,185	[1]	(39)
Amortization		(30,620)		(6,484)	$ (7,012)
Goodwill impairment loss		0		0
Intangible asset impairment loss	[2]	0		(5,450)	0
Goodwill and intangible assets, foreign currency translation		(7,010)
Gross balance		684,694
Intangible assets with finite lives, accumulated amortization		(118,274)
Accumulated impairment losses		(5,450)
Accumulated foreign currency translation		(7,010)
Net balance		553,960		153,405	165,378
Goodwill
Schedule Of Goodwill And Intangible Assets [Line Items]
Net beginning balance		91,238		91,293
Additions		87,367	[1]	(55)
Amortization		0		0
Goodwill impairment loss				0
Goodwill, foreign currency translation		(2,150)
Gross balance		178,605
Intangible assets with finite lives, accumulated amortization		0
Goodwill accumulated impairment loss		0
Accumulated foreign currency translation		(2,150)
Net balance		176,455		91,238	91,293
Intangible assets with indefinite lives
Schedule Of Goodwill And Intangible Assets [Line Items]
Net beginning balance		11,779		17,229
Additions		57,600	[1]	0
Amortization		0		0
Intangible asset impairment loss				(5,450)
Indefinite-lived intangible assets, foreign currency translation		0
Intangible assets with indefinite lives, Gross balance		74,829
Intangible assets with finite lives, accumulated amortization		0
Accumulated impairment losses		(5,450)
Accumulated foreign currency translation		0
Net balance		69,379		11,779	17,229
Intangible assets with finite lives
Schedule Of Goodwill And Intangible Assets [Line Items]
Net beginning balance		50,388		56,856
Additions		293,218	[1]	16
Amortization		(30,620)		(6,484)
Finite-lived intangible assets, impairment loss				0
Finite-lived intangible assets, foreign currency translation		(4,860)
Intangible assets with finite lives, Gross balance		431,260
Intangible assets with finite lives, accumulated amortization		(118,274)
Intangible assets with finite lives, accumulated impairment losses		0
Accumulated foreign currency translation		(4,860)
Net balance		$ 308,126		$ 50,388	$ 56,856
[1]	(1) For additional information on the intangible assets acquired during 2015, see Note 3, Acquisition of Montpelier.
[2]	For additional information on the Company's intangible assets, see Note 11, Goodwill and intangible assets.

Commitments And Contingencies95

Commitments And Contingencies (Narrative) (Details) $ in Thousands	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Commitments and Contingencies Disclosure [Abstract]
Collateral held related to ceded reinsurance agreements	$ 321,500	$ 199,700
Securities pledged as collateral obligation	$ 108,900	130,600
Number of custodians	6
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	$ 1,195,970	889,086
U.S. Government Sponsored Reinsurance Program [Member]
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	234,600	339,600
A- or better by A.M. Best or Standard And Poors [Member]
Ceded Credit Risk [Line Items]
Reinsurance Recoverables	$ 941,500	$ 542,500

Commitments And Contingencies96

Commitments And Contingencies (Schedule Of Percentage Of Gross Premiums Written) (Details) - Sales [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue, Major Customer [Line Items]
Percentage of gross premium written	41.80%	42.90%	42.80%
Marsh & McLennan Companies, Inc.
Revenue, Major Customer [Line Items]
Percentage of gross premium written	19.80%	19.10%	17.30%
Aon Benfield
Revenue, Major Customer [Line Items]
Percentage of gross premium written	12.80%	13.20%	15.60%
Willis Companies
Revenue, Major Customer [Line Items]
Percentage of gross premium written	9.20%	10.60%	9.90%

Commitments And Contingencies97

Commitments And Contingencies (LOC) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Cash and investments pledged under letters of credit facility	$ 383.3	$ 240
Amount of letters of credit outstanding	$ 341.6	$ 209.9

Commitments And Contingencies98

Commitments And Contingencies (Deposits) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
United States
Statutory Accounting Practices [Line Items]
Assets Held by Insurance Regulators	$ 208.3	$ 205.2

Commitments And Contingencies99

Commitments And Contingencies (Assets Held In Trust) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets Held In Trust [Line Items]
Cash and cash equivalents	$ 1,177,750	$ 745,472	$ 845,851	$ 1,124,019
Blue Water Re Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	438,900
BW Retrocessional Agreement [Member]
Assets Held In Trust [Line Items]
Cash and cash equivalents	195,300
Blue Capital Re ILS Trusts [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	5,200
Endurance Reinsurance Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	94,100
Reduced Collateral Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	10,800
MUSIC Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	21,300
Montpelier Reinsurance Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	20,000
FL Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	10,000
Lloyd's Premiums Trust Funds [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	231,900
Cash and cash equivalents	$ 23,800

Commitments And Contingencie100

Commitments And Contingencies (Lloyd's New Central Fund) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
Levy Imposed As Percentage Of Premiums Written	0.50%
Additional Contribution As Percentage Of Underwriting Capacity Maximum	3.00%
Estimated Obligation To Central Fund For Annual Contribution	$ 1
Annual Subscription Charge As Percentage Of Premium Written	0.50%
Estimated Obligation For Annual Subscription Charges	$ 1

Commitments And Contingencie101

Commitments And Contingencies (Schedule Of Future Minimum Lease Commitments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 15,375
2,017	16,222
2,018	15,716
2,019	15,986
2,020	14,408
2,021	27,295
Total	105,002
Total lease expense under operating leases	16,500	$ 14,700	$ 14,700
Total sublease income under operating leases	$ 1,300	$ 1,300	$ 800

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) $ / shares in Units, $ in Thousands	Dec. 24, 2015shares	Nov. 24, 2015USD ($)$ / sharesshares	Jun. 01, 2011USD ($)$ / sharesshares	Oct. 10, 2005USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)	Feb. 27, 2014shares
Class of Stock [Line Items]
Preferred Stock, Shares Issued | shares					9,209,200	17,200,000
Number of restricted shares outstanding | shares					1,357,279
Net proceeds on issuance of preferred shares | $					$ 222,963	$ 0	$ 0
Shares authorized to be repurchased | shares								5,000,000
Treasury Stock, Shares, Acquired | shares					0
Total authorized repurchases remaining shares | shares					5,000,000	5,000,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Issued | shares				8,000,000	8,000,000	8,000,000
Stock Redeemed or Called During Period, Shares | shares	8,000,000
Preferred stock, dividend percentage				7.75%
Preferred stock price at issue				$ 25
Net proceeds on issuance of preferred shares | $				$ 193,500
Preferred stock redemption price per share				$ 25
Series B Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Issued | shares			9,200,000		9,200,000	9,200,000
Preferred stock, dividend percentage			7.50%
Preferred stock price at issue			$ 25
Net proceeds on issuance of preferred shares | $			$ 224,000
Preferred stock redemption price per share			$ 25
Preferred stock redemption price per share before stated redemption date			26
Preferred stock, liquidation price per share			$ 25
Series C Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Issued | shares		9,200			9,200	0
Preferred stock, dividend percentage		6.35%
Preferred Stock Shares Issued Depositary Shares | shares		9,200,000
Preferred stock price at issue		$ 25,000
Net proceeds on issuance of preferred shares | $		$ 222,000
Preferred stock redemption price per share		$ 25,000
Preferred Stock Early Redemption Amount Depositary Share					$ 26
Preferred stock redemption price per share before stated redemption date		26,000
Preferred stock, liquidation price per share		25,000
Preferred Stock Liquidation Preference Depositary Shares		$ 25
Preferred Stock Interest In Share		0.001

Shareholders' Equity (Schedule

Shareholders' Equity (Schedule Of Company's Share Capital) (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Capital Unit [Line Items]
Preferred Stock, Shares Authorized	9,209,200	17,200,000
Preferred Stock, Shares Issued	9,209,200	17,200,000
Preferred Stock, Shares Outstanding	9,209,200	17,200,000
Common Stock, Shares Authorized	120,000,000	120,000,000
Common shares, ordinary, number of shares issued	66,797,991	44,765,153
Common shares, ordinary, number of shares outstanding	66,797,991	44,765,153
Preferred Stock, Par or Stated Value Per Share	$ 1
Common Stock, Par or Stated Value Per Share	$ 1
Preferred shares, total liquidation preference	$ 460,000	$ 430,000
Series A Preferred Stock [Member]
Capital Unit [Line Items]
Preferred Stock, Shares Issued	0	8,000,000
Preferred Stock, Shares Outstanding	0	8,000,000
Preferred Stock, Par or Stated Value Per Share	$ 1
Preferred shares, total liquidation preference	$ 0	$ 200,000
Series B Preferred Stock [Member]
Capital Unit [Line Items]
Preferred Stock, Shares Issued	9,200,000	9,200,000
Preferred Stock, Shares Outstanding	9,200,000	9,200,000
Preferred Stock, Par or Stated Value Per Share	$ 1
Preferred shares, total liquidation preference	$ 230,000	$ 230,000
Series C Preferred Stock [Member]
Capital Unit [Line Items]
Preferred Stock, Shares Issued	9,200	0
Preferred Stock, Shares Outstanding	9,200	0
Preferred shares, total liquidation preference	$ 230,000	$ 0

Shareholders' Equity (Schedu104

Shareholders' Equity (Schedule Of Changes In Accumulated Other Comprehensive (Loss) Income By Component) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive (Loss) Income [Line Items]
Beginning balance		$ 76,706	$ 62,731
Other comprehensive (loss) income before reclassifications		(90,631)	34,368
Amounts reclassified from accumulated other comprehensive (loss) income	[1]	(32,709)	(20,393)
Net current period other comprehensive (loss) income		(123,340)	13,975	$ (89,732)
Ending balance		(46,634)	76,706	62,731
Losses on cash flow hedges
Accumulated Other Comprehensive (Loss) Income [Line Items]
Beginning balance		(1,766)	(1,855)
Other comprehensive (loss) income before reclassifications		0	0
Amounts reclassified from accumulated other comprehensive (loss) income	[1]	88	89
Net current period other comprehensive (loss) income		88	89
Ending balance		(1,678)	(1,766)	(1,855)
Unrealized (losses) gains on available for sale securities
Accumulated Other Comprehensive (Loss) Income [Line Items]
Beginning balance		86,100	45,950
Other comprehensive (loss) income before reclassifications		(65,941)	60,632
Amounts reclassified from accumulated other comprehensive (loss) income	[1]	(32,797)	(20,482)
Net current period other comprehensive (loss) income		(98,738)	40,150
Ending balance		(12,638)	86,100	45,950
Foreign currency translation adjustments
Accumulated Other Comprehensive (Loss) Income [Line Items]
Beginning balance		(7,628)	18,636
Other comprehensive (loss) income before reclassifications		(24,690)	(26,264)
Amounts reclassified from accumulated other comprehensive (loss) income	[1]	0	0
Net current period other comprehensive (loss) income		(24,690)	(26,264)
Ending balance		$ (32,318)	$ (7,628)	$ 18,636
[1]	All amounts are net of tax.

Shareholders' Equity (Schedu105

Shareholders' Equity (Schedule Of Reclassifications Out Of Accumulated Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive (Loss) Income [Line Items]
Interest expense									$ 41,260	$ 40,968	$ 36,188
Net realized and unrealized gains	$ 20,238	$ (5,029)	$ (9,680)	$ (18,189)	$ 3,788	$ (9,788)	$ (3,411)	$ (4,872)	(12,660)	(14,283)	(15,164)
Net impairment losses recognized in earnings	2,604	38	424	649	214	102	198	111	3,715	625	1,616
Income before income taxes									(359,473)	(348,840)	(317,768)
Income tax expense									(4,362)	(390)	(5,853)
Total net of income taxes	$ (99,587)	$ (51,823)	$ (84,206)	$ (108,479)	$ (84,573)	$ (76,234)	$ (83,163)	$ (104,480)	(344,095)	(348,450)	$ (311,915)
Reclassification Adjustment Out Of Accumulated Other Comprehensive (Loss) Income [Member] | Losses on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive (Loss) Income [Line Items]
Interest expense									88	89
Income before income taxes									88	89
Income tax expense									0	0
Total net of income taxes									88	89
Reclassification Adjustment Out Of Accumulated Other Comprehensive (Loss) Income [Member] | Unrealized (gains) losses on available for sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive (Loss) Income [Line Items]
Net realized and unrealized gains									(37,245)	(19,406)
Net impairment losses recognized in earnings									3,715	625
Income before income taxes									(33,530)	(18,781)
Income tax expense									(733)	1,701
Total net of income taxes									$ (32,797)	$ (20,482)

Earnings Per Share (Schedule Of

Earnings Per Share (Schedule Of Computation Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income available to common and participating common shareholders		$ 91,401	$ 43,635	$ 76,018	$ 100,291	$ 76,387	$ 68,046	$ 74,975	$ 96,292	$ 311,345	$ 315,700	$ 279,165
Less amount allocated to participating common shareholders	[1]									(8,749)	(9,118)	(6,444)
Net income allocated to common shareholders										$ 302,596	$ 306,582	$ 272,721
Weighted average shares - basic										52,707,390	43,368,062	42,817,624
Weighted average shares - diluted										52,828,503	43,415,243	42,818,207
Basic earnings per common share		$ 1.36	$ 0.73	$ 1.69	$ 2.24	$ 1.71	$ 1.52	$ 1.68	$ 2.16	$ 5.74	$ 7.07	$ 6.37
Diluted earnings per common share		$ 1.36	$ 0.73	$ 1.68	$ 2.23	$ 1.70	$ 1.52	$ 1.68	$ 2.16	$ 5.73	$ 7.06	$ 6.37
Restricted Stock [Member]
Share equivalents:										2,721	70	583
Employee Stock Option [Member]
Share equivalents:										118,392	47,111	0
[1]	Represents earnings and dividends attributable to holders of unvested restricted shares and restricted share units issued under the Company's stock compensation plans that are considered participating. In periods of loss, no losses are allocated to participating common shareholders (unvested restricted shares and restricted share units).

Earnings Per Share (Schedule107

Earnings Per Share (Schedule Of Dividends Declared) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Dividends Declared [Line Items]
Dividends declared per common share	$ 1.40	$ 1.36	$ 1.28
Series A Preferred Stock [Member]
Dividends Declared [Line Items]
Dividends declared per preferred share	1.9375	1.9375	1.9375
Series B Preferred Stock [Member]
Dividends Declared [Line Items]
Dividends declared per preferred share	1.8750	1.8750	1.8750
Series C Preferred Stock [Member]
Dividends Declared [Line Items]
Dividends declared per preferred share	$ 0	$ 0	$ 0

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Investment expenses	$ 16,486	$ 14,284	$ 13,931
Pyramis Global Advisors [Member]
Related Party Transaction [Line Items]
Ordinary shares owned by related parties	3.5
Percentage of ordinary shares owned by related parties	5.20%
Investment expenses	$ 1,300	1,400	1,400
Accrued investment expenses	$ 200	300
BlackRock Inc [Member]
Related Party Transaction [Line Items]
Ordinary shares owned by related parties	4.1
Percentage of ordinary shares owned by related parties	6.10%
Investment expenses	$ 3,600	3,200	$ 2,900
Accrued investment expenses	$ 1,600	$ 1,500

Stock-Based Employee Compens109

Stock-Based Employee Compensation And Other Stock Plans (Narrative) (Details) - USD ($)	Aug. 03, 2015	Jul. 31, 2015	May. 28, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	May. 20, 2015	May. 11, 2011	Feb. 23, 2011	Feb. 11, 2010	Feb. 28, 2007	Oct. 26, 2005
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares authorized for issuance				2,463,798	1,738,370
Number of additional ordinary shares authorized after acquisition of Montpelier	842,755
Contractual life of stock options			10 years
Number of options granted				0		800,000
Number of options expired				0	0	0
Number of options vested				160,000	160,000	160,000
Number of options exercised				480,000
Total intrinsic value of options exercised				$ 9,500,000	$ 300,000	$ 500,000
Proceeds from stock options exercised				23,100,000
Unrecognized stock based compensation expenses related to unvested stock options				$ 1,000,000	$ 2,600,000
Vesting period for employee awards				4 years
Restricted share awards to non-employee directors, vesting period				1 year
Number of restricted shares granted				546,253	505,997	503,097
Restricted shares weighted average grant date, aggregate fair value				$ 91,200,000	$ 26,700,000	$ 58,100,000
Options weighted average grant date fair value						10,200,000
Aggregate fair value of restricted shares and RSUs vested				60,000,000	18,700,000	17,100,000
Compensation costs not yet recognized related to unvested restricted shares and restricted share units				$ 26,700,000	$ 23,300,000
Exchange ratio		0.472
RSUs assumed				841,926	0
Weighted average remaining contractual life in years, options outstanding, end of year				7 years 4 months 28 days
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting rate				20.00%
Contractual life of stock options				10 years
Vesting period for employee awards				5 years
Compensation costs recognized				$ 1,600,000	$ 3,100,000	4,500,000
Percentage of compensation expense to be expensed next year				78.90%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for employee awards				4 years
Restricted share awards to non-employee directors, vesting period				12 months
Compensation costs recognized				$ 53,900,000	27,900,000	23,500,000
Percentage of compensation expense to be expensed next year				65.30%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for employee awards				3 years
Stock Based Employee Compensation Plans Two Thousand Seven Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ordinary shares authorized for issuance		5,763,104								1,795,000	2,100,000
Number of additional ordinary shares authorized after acquisition of Montpelier		1,025,349
2005 Employee Share Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance under ESPP								400,000	200,000			200,000
2015 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period shares are restricted from sale, transfer, or certification				1 year
Shares reserved for issuance under ESPP							300,000
Percentage of employee share purchase plans discount closing market price				15.00%
Expenses related to employee stock purchase plan				$ 298,000	$ 234,000	$ 167,000
Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted shares granted			708,890
Share-based Compensation Award, Tranche One [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rate of restricted shares on death, disability or change of control, percentage				50.00%

Stock-Based Employee Compens110

Stock-Based Employee Compensation And Other Stock Plans (Options Narrative) (Details) $ / shares in Units, $ in Millions	May. 28, 2013$ / sharesshares	Dec. 31, 2015$ / sharesshares	Dec. 31, 2014shares	Dec. 31, 2013USD ($)shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Options weighted average grant date fair value | $				$ 10.2
Number of options granted		0
Weighted average exercise price of options granted in period | $ / shares		$ 0
Number of options expired		0	0	0
Contractual life of stock options	10 years
Chief Executive Officer [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of options granted	800,000
Weighted average exercise price of options granted in period | $ / shares	$ 48.20
Chief Executive Officer [Member] | Employee Stock Option [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of tranches	5
Chief Executive Officer [Member] | Restricted Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of tranches	5

Stock-Based Employee Compens111

Stock-Based Employee Compensation And Other Stock Plans (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average remaining contractual life in years, options outstanding, end of year	7 years 4 months 28 days
Number of options granted	0	800,000
Aggregate Intrinsic Value, Outstanding, end of year	$ 5,053
Aggregate Intrinsic Value, Exercisable and vested options, end of year	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, beginning of year	800,000
Number of options granted	0
Number of options exercised	(480,000)
Number of options forfeited	0
Number of options outstanding, end of year	320,000
Number of options exercisable and vested, end of year	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning of year	$ 48.20
Weighted average Exercise Price, Granted	0
Weighted Average Exercise Price, Exercised	48.20
Weighted Average Exercise Price, Forfeited	0
Weighted Average Exercise Price, Outstanding, end of year	48.20
Weighted Average Exercise Price, Exercisable and vested options, end of year	$ 0

Stock-Based Employee Compens112

Stock-Based Employee Compensation And Other Stock Plans (Restricted Share And Restricted Share Unit Activity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning of year	1,290,894
Granted and assumed	1,388,179
Settled	(997,068)
Forfeited	(18,423)
Unvested, end of year	1,663,582
Number of Shares/Units, Outstanding, end of year	1,290,894	1,663,582
Aggregate Intrinsic Value, Outstanding, end of year		$ 106,453

Pension Plan (Details)

Pension Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Contribution Plan Disclosure [Line Items]
Expenses related to contributions	$ 13.8	$ 12.6	$ 10.8
Low
Defined Contribution Plan Disclosure [Line Items]
Percentage of defined contributions per employee	4.00%
High
Defined Contribution Plan Disclosure [Line Items]
Percentage of defined contributions per employee	12.00%

Statutory Requirements And D114

Statutory Requirements And Dividend Restrictions (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Statutory Requirements And Dividend Restrictions [Line Items]
Retained earnings	$ 2,681,053	$ 2,448,285
Contributed surplus	$ 2,145,836	598,226
Period to notify the PRA, days	28 days
Armtech [Member]
Statutory Requirements And Dividend Restrictions [Line Items]
Payable dividend without prior regulatory approval	$ 3,500	3,700
Endurance Bermuda
Statutory Requirements And Dividend Restrictions [Line Items]
Payable dividend without prior regulatory approval	1,034,400	$ 719,200
Endurance Bermuda | Low
Statutory Requirements And Dividend Restrictions [Line Items]
Required statutory capital	$ 100,000
Endurance US Subsidiaries
Statutory Requirements And Dividend Restrictions [Line Items]
Dividend payable rate, maximum	10.00%
Blue Water Re
Statutory Requirements And Dividend Restrictions [Line Items]
Statutory net assets	$ 269,600
Blue Water Re II
Statutory Requirements And Dividend Restrictions [Line Items]
Statutory net assets	212,500
Blue Capital Re
Statutory Requirements And Dividend Restrictions [Line Items]
Payable dividend without prior regulatory approval	50,600
Lloyd's Capital Trust [Member] | Endurance Bermuda
Statutory Requirements And Dividend Restrictions [Line Items]
Assets Held-in-trust	$ 276,800

Statutory Requirements And D115

Statutory Requirements And Dividend Restrictions (Combined Statutory Capital and Statutory Net Income (Loss)) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Bermuda
Statutory Accounting Practices [Line Items]
Required statutory capital	[1],[2]	$ 1,276,453	$ 955,903
Actual statutory capital	[1],[2]	4,307,249	2,876,927
Statutory net income (loss)		417,298	453,127	$ 454,840
United States
Statutory Accounting Practices [Line Items]
Required statutory capital		281,905	244,587
Actual statutory capital		768,791	702,513
Statutory net income (loss)		70,398	28,450	(48,035)
United Kingdom
Statutory Accounting Practices [Line Items]
Required statutory capital	[3]	84,086	73,741
Actual statutory capital	[3]	538,265	555,283
Statutory net income (loss)		969	4,135	27,976
Singapore
Statutory Accounting Practices [Line Items]
Required statutory capital		3,524	3,773
Actual statutory capital		49,842	32,272
Statutory net income (loss)		$ 17,542	$ 4,111	$ 8,702
[1]	Bermuda includes the statutory capital of Endurance Bermuda and its foreign branches.
[2]	Bermuda statutory capital includes an investment in affiliate asset, which represents its interest in the remaining insurance and reinsurance operations of the Company included in the United States and U.K. columns above.
[3]	U.K. includes the statutory capital of Endurance U.K.

Taxes (Narrative) (Details)

Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Expense Benefit [Line Items]
Current income tax expense	$ (6,262)	$ (1,804)	$ (3,089)
Deferred income tax benefit (expense)	$ 1,900	1,414	(2,764)
Combined effective tax rate (Bermuda)	0.00%
Total income tax paid	$ (2,400)	(900)
Income tax refunds received			8,400
Valuation allowance	(131,138)	(121,409)
United States
Income Tax Expense Benefit [Line Items]
Current income tax expense	4,200	1,800	3,100
Deferred income tax benefit (expense)	(700)	(1,400)	$ 2,800
Net operating loss carryforwards	155,400
United Kingdom
Income Tax Expense Benefit [Line Items]
Current income tax expense	2,200	0
Deferred income tax benefit (expense)	(200)	0
Net operating loss carryforwards	112,300
Switzerland
Income Tax Expense Benefit [Line Items]
Current income tax expense	(100)	0
Deferred income tax benefit (expense)		$ 0
Net operating loss carryforwards	56,600
Singapore
Income Tax Expense Benefit [Line Items]
Net operating loss carryforwards	49,900
Bermuda
Income Tax Expense Benefit [Line Items]
Deferred income tax benefit (expense)	$ (1,000)

Taxes (Income Tax Expense) (Det

Taxes (Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Current income tax expense	$ (6,262)	$ (1,804)	$ (3,089)
Deferred income tax benefit (expense)	1,900	1,414	(2,764)
Income tax expense	$ (4,362)	$ (390)	$ (5,853)

Taxes (Income Tax Rate Reconcil

Taxes (Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Computed expected tax expense	$ 0	$ 0	$ 0
Tax (expense) benefit effect on foreign taxes	(8,071)	(1,661)	31,054
Change in valuation allowance	3,709	1,271	(36,907)
Income tax expense	$ (4,362)	$ (390)	$ (5,853)

Taxes (Schedule Of Net Deferred

Taxes (Schedule Of Net Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unearned premiums	$ 25,172	$ 23,124
Loss reserves	27,370	29,410
Net operating loss carryforward	92,844	93,163
Deferred compensation	25,268	19,588
Deferred interest	46,568	44,951
Realized investment losses	4,972	125
Other	11,077	10,404
Total deferred income tax assets	233,271	220,765
Deferred acquisition costs	(8,179)	(10,843)
Unrealized investment losses (gains)	1,568	(5,293)
Unrealized foreign exchange gains	(4,087)	(2,704)
Temporary differences related to acquisition	(35,461)	(20,344)
Start up costs	1,565	1,144
Other	(7,561)	(10,033)
Total deferred income tax liabilities	(55,285)	(50,361)
Valuation allowance	(131,138)	(121,409)
Net deferred income tax asset	$ 46,848	$ 48,995

Taxes (Schedule Of Distribution

Taxes (Schedule Of Distribution Of Income Before Income Taxes) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
U.S. (domestic)		$ 95,649	$ 60,112	$ 13,103
Non-U.S. (foreign)	[1]	263,824	288,728	304,665
Income before income taxes		$ 359,473	$ 348,840	$ 317,768
[1]	The Company's non-U.S. (foreign) operating subsidiaries write business that is exposed to risks originating in the United States.

Taxes (Montpelier Valuation All

Taxes (Montpelier Valuation Allowance) (Details) - Montpelier Re Holdings Ltd [Member] $ in Millions	Dec. 31, 2015USD ($)
Valuation Allowance [Line Items]
Operating Loss Carryforwards, Valuation Allowance	$ 11.3
Capital Loss Carryforwards Valuation Allowance	0.7
Loss Carryforward Available Per Year	$ 0.2

Condensed Unaudited Quarterl122

Condensed Unaudited Quarterly Financial Data (Summary Of The Unaudited Quarterly Data) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								5 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Net premiums earned	$ 573,456	$ 557,003	$ 458,135	$ 389,859	$ 471,279	$ 514,895	$ 481,538	$ 396,266		$ 1,978,453	$ 1,863,978	$ 2,016,484
Net investment income	23,180	16,533	32,252	41,861	25,894	25,357	39,302	40,990		113,826	131,543	166,216
Net realized and unrealized gains (losses)	(20,238)	5,029	9,680	18,189	(3,788)	9,788	3,411	4,872		12,660	14,283	15,164
Net impairment losses recognized in earnings	(2,604)	(38)	(424)	(649)	(214)	(102)	(198)	(111)		(3,715)	(625)	(1,616)
Subtotal	573,794	578,527	499,643	449,260	493,171	549,938	524,053	442,017
Net losses and loss expenses	242,057	263,993	239,122	171,936	243,801	290,269	259,196	176,896		917,108	970,162	1,219,684
Acquisition, general and administrative, and corporate expenses	194,726	225,558	152,570	149,251	148,374	174,307	165,056	145,363
Net foreign exchange losses (gains)	(2,190)	8,621	12,981	7,552	(227)	783	319	2,964		26,964	3,839	14,214
Net income	107,896	54,530	84,206	108,479						355,111	348,450	311,915
Net income attributable to non-controlling interests	(8,309)	(2,707)	0	0					$ (11,016)	(11,016)	0	0
Net income available to Endurance Holdings	99,587	51,823	84,206	108,479	84,573	76,234	83,163	104,480		344,095	348,450	311,915
Preferred dividends	(8,186)	(8,188)	(8,188)	(8,188)	(8,186)	(8,188)	(8,188)	(8,188)		(32,750)	(32,750)	(32,750)
Net income available to Endurance Holdings' common and participating common shareholders	$ 91,401	$ 43,635	$ 76,018	$ 100,291	$ 76,387	$ 68,046	$ 74,975	$ 96,292		$ 311,345	$ 315,700	$ 279,165
Basic earnings per share	$ 1.36	$ 0.73	$ 1.69	$ 2.24	$ 1.71	$ 1.52	$ 1.68	$ 2.16		$ 5.74	$ 7.07	$ 6.37
Diluted earnings per share	$ 1.36	$ 0.73	$ 1.68	$ 2.23	$ 1.70	$ 1.52	$ 1.68	$ 2.16		$ 5.73	$ 7.06	$ 6.37

Schedule I Summary Of Invest123

Schedule I Summary Of Investments Other Than Investments In Related Parties (Summary Of Investments Other Than Investments In Related Parties) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	$ 7,687,617	[1]
Market Value	7,767,406
Amount at Which Shown on the Balance Sheet	7,767,406
U.S. government and government agencies and authorities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	820,461	[1]
Market Value	818,468
Amount at Which Shown on the Balance Sheet	818,468
States, municipalities and political subdivisions
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	22,456	[1]
Market Value	22,406
Amount at Which Shown on the Balance Sheet	22,406
Foreign governments
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	160,941	[1]
Market Value	160,976
Amount at Which Shown on the Balance Sheet	160,976
Corporate bonds
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	1,920,230	[1]
Market Value	1,907,687
Amount at Which Shown on the Balance Sheet	1,907,687
Agency mortgage-backed securities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	1,326,164	[1]
Market Value	1,335,678
Amount at Which Shown on the Balance Sheet	1,335,678
Non-agency mortgage-backed securities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	792,489	[1]
Market Value	788,581
Amount at Which Shown on the Balance Sheet	788,581
Collateralized loan and debt obligations
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	419,795	[1]
Market Value	405,128
Amount at Which Shown on the Balance Sheet	405,128
Asset-backed securities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	510,540	[1]
Market Value	507,255
Amount at Which Shown on the Balance Sheet	507,255
Fixed maturity investments
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	5,973,076	[1]
Market Value	5,946,179
Amount at Which Shown on the Balance Sheet	5,946,179
Short-term investments
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	419,753	[1]
Market Value	419,796
Amount at Which Shown on the Balance Sheet	419,796
Equity securities
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	557,719	[1]
Market Value	528,814
Amount at Which Shown on the Balance Sheet	528,814
Other investments
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]
Cost	737,069	[1]
Market Value	872,617
Amount at Which Shown on the Balance Sheet	$ 872,617
[1]	Investments in fixed maturity investments and short-term investments are shown at amortized cost.

Schedule II Condensed Financ124

Schedule II Condensed Financial Statement Information Of The Registrant (Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jul. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Preferred Stock, Shares Issued	9,209,200		17,200,000
Preferred Stock, Shares Outstanding	9,209,200		17,200,000
Common shares, ordinary, number of shares issued	66,797,991		44,765,153
Common shares, ordinary, number of shares outstanding	66,797,991		44,765,153
Assets [Abstract]
Cash and cash equivalents	$ 1,177,750		$ 745,472	$ 845,851	$ 1,124,019
Goodwill and intangible assets	553,960		153,405	165,378
Other assets	187,383		195,277
Total assets	13,241,525		9,640,684
Liabilities [Abstract]
Debt	717,650		523,617
Deferred tax liability	17,315		0
Other liabilities	344,596		287,978
Total liabilities	8,117,453		6,455,502
Stockholders' Equity Attributable to Parent [Abstract]
Series A, B and C, non-cumulative - 9,209,200 issued and outstanding (2014 - 17,200,000)	9,209		17,200
Common shares, ordinary - 66,797,991 issued and outstanding (2014 - 44,765,153)	66,798		44,765
Additional paid-in capital	2,145,836		598,226
Accumulated other comprehensive (loss) income	(46,634)		76,706	62,731
Retained earnings	2,681,053		2,448,285
Total shareholders' equity available to Endurance Holdings	4,856,262		3,185,182	2,886,549
Non-controlling interests	267,810	$ 258,529	0	0
Total shareholders' equity	5,124,072		3,185,182
Total liabilities and shareholders' equity	$ 13,241,525		$ 9,640,684
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Preferred Stock, Shares Issued	9,209,200		17,200,000
Preferred Stock, Shares Outstanding	9,209,200		17,200,000
Common shares, ordinary, number of shares issued	66,797,991		44,765,153
Common shares, ordinary, number of shares outstanding	66,797,991		44,765,153
Assets [Abstract]
Investment in subsidiary	$ 5,582,764		$ 3,518,589
Cash and cash equivalents	3,206		240	$ 6,517	$ 10,083
Amounts due from subsidiaries	105,497		201,600
Goodwill and intangible assets	170,290		0
Other assets	14,435		9,829
Total assets	5,876,192		3,730,258
Liabilities [Abstract]
Debt	707,591		523,518
Deferred tax liability	17,315		0
Other liabilities	27,214		21,558
Total liabilities	752,120		545,076
Stockholders' Equity Attributable to Parent [Abstract]
Series A, B and C, non-cumulative - 9,209,200 issued and outstanding (2014 - 17,200,000)	9,209		17,200
Common shares, ordinary - 66,797,991 issued and outstanding (2014 - 44,765,153)	66,798		44,765
Additional paid-in capital	2,145,836		598,226
Accumulated other comprehensive (loss) income	(46,634)		76,706
Retained earnings	2,681,053		2,448,285
Total shareholders' equity available to Endurance Holdings	4,856,262		3,185,182
Non-controlling interests	267,810		0
Total shareholders' equity	5,124,072		3,185,182
Total liabilities and shareholders' equity	$ 5,876,192		$ 3,730,258

Schedule II Condensed Financ125

Schedule II Condensed Financial Statement Information Of The Registrant (Statements of Income) (Details) - USD ($) $ in Thousands	3 Months Ended								5 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Net investment income	$ 23,180	$ 16,533	$ 32,252	$ 41,861	$ 25,894	$ 25,357	$ 39,302	$ 40,990		$ 113,826	$ 131,543	$ 166,216
Net realized and unrealized gains (losses)	(20,238)	5,029	9,680	18,189	(3,788)	9,788	3,411	4,872		12,660	14,283	15,164
Total revenues										2,097,530	2,003,393	2,194,202
Expenses
General and administrative expenses										259,791	247,387	236,873
Amortization of intangibles										30,620	6,484	7,012
Net foreign exchange losses (gains)	(2,190)	8,621	12,981	7,552	(227)	783	319	2,964		26,964	3,839	14,214
Interest expense										41,260	40,968	36,188
Income before income taxes										359,473	348,840	317,768
Income tax benefit										(4,362)	(390)	(5,853)
Net income	107,896	54,530	84,206	108,479						355,111	348,450	311,915
Net income attributable to non-controlling interests	(8,309)	(2,707)	0	0					$ (11,016)	(11,016)	0	0
Net income available to Endurance Holdings	99,587	51,823	84,206	108,479	84,573	76,234	83,163	104,480		344,095	348,450	311,915
Preferred dividends	(8,186)	(8,188)	(8,188)	(8,188)	(8,186)	(8,188)	(8,188)	(8,188)		(32,750)	(32,750)	(32,750)
Net income available to common and participating common shareholders	$ 91,401	$ 43,635	$ 76,018	$ 100,291	$ 76,387	$ 68,046	$ 74,975	$ 96,292		311,345	315,700	279,165
Parent Company [Member]
Revenues
Net investment income										9	248	0
Net realized and unrealized gains (losses)										332	1,957	(1,511)
Other income										10,200	10,200	10,200
Total revenues										10,541	12,405	8,689
Expenses
General and administrative expenses										93,237	61,325	48,017
Amortization of intangibles										6,675	0	0
Net foreign exchange losses (gains)										5	(1)	0
Interest expense										41,188	40,968	36,188
Total expenses										141,105	102,292	84,205
Loss before income taxes and equity in net income of subsidiaries										(130,564)	(89,887)	(75,516)
Equity in net income of subsidiaries										484,644	438,337	387,431
Income before income taxes										354,080	348,450	311,915
Income tax benefit										1,031	0	0
Net income										355,111	348,450	311,915
Net income attributable to non-controlling interests										(11,016)	0	0
Net income available to Endurance Holdings										344,095	348,450	311,915
Preferred dividends										(32,750)	(32,750)	(32,750)
Net income available to common and participating common shareholders										$ 311,345	$ 315,700	$ 279,165

Schedule II Condensed Financ126

Schedule II Condensed Financial Statement Information Of The Registrant (Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows used in operating activities:
Net income	$ 107,896	$ 54,530	$ 84,206	$ 108,479	$ 355,111	$ 348,450	$ 311,915
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization					51,457	27,234	21,250
Net realized and unrealized (gains) losses					(12,660)	(14,283)	(15,164)
Deferred taxes					(2,727)	(1,414)	2,412
Stock-based compensation expense					55,512	31,006	27,988
Other assets					(25,683)	(17,132)	(10,372)
Other liabilities					76,194	127,036	54,376
Net cash flows provided by operating activities					245,457	266,261	157,924
Cash flows provided by investing activities:
Proceeds from sales and maturities of available for sale investments					5,725,794	4,145,940	4,023,339
Purchases of available for sale investments					(5,421,949)	(4,449,225)	(4,259,800)
Purchases of fixed assets					(26,988)	(40,932)	(24,960)
Net cash received for subsidiary acquisition					675,624	39
Net cash flows provided by (used in) investing activities					486,793	(236,881)	(347,777)
Cash flows used in financing activities
Issuance of common shares					24,823	2,305	31,884
Issuance of Series C, non-cumulative preferred shares					222,963	0	0
Redemption of Series A, non-cumulative preferred shares					(200,000)	0	0
Offering and registration costs paid					(617)	0	0
Bridge facility costs paid					0	(4,750)	0
Repurchase of common shares					0	0	(14,584)
Settlement of restricted shares					(14,535)	(4,039)	(3,001)
Repayments of debt					(199,454)	(686)	(768)
Dividends paid on preferred shares					(32,750)	(32,750)	(32,750)
Dividends paid on common shares					(78,473)	(60,524)	(55,906)
Net cash flows used in financing activities					(274,774)	(99,738)	(74,422)
Net increase (decrease) in cash and cash equivalents					432,278	(100,379)	(278,168)
Cash and cash equivalents, beginning of year				745,472	745,472	845,851	1,124,019
Cash and cash equivalents, end of year	1,177,750				1,177,750	745,472	845,851
Parent Company [Member]
Cash flows used in operating activities:
Net income					355,111	348,450	311,915
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization					8,855	6,785	1,504
Net realized and unrealized (gains) losses					(332)	(1,957)	1,511
Deferred taxes					(1,031)	0	0
Stock-based compensation expense					28,604	15,093	20,708
Equity in net earnings of subsidiary					(484,644)	(438,337)	(387,431)
Other assets					(893)	(177)	2,112
Other liabilities					(17,377)	1,626	2,942
Net cash flows provided by operating activities					(111,707)	(68,517)	(46,739)
Cash flows provided by investing activities:
Proceeds from sales and maturities of available for sale investments					0	26,094	0
Purchases of available for sale investments					0	(24,137)	0
Contributions of capital made to subsidiaries					0	0	(10,389)
Returns of capital received from subsidiaries					0	0	10,289
Dividends received from subsidiary					341,524	145,203	118,278
Net amounts received from subsidiaries					35,383	14,819	7,650
Purchases of fixed assets					(11,626)	0	(8,298)
Proceeds from disposals of fixed assets					6,606	19	0
Net cash received for subsidiary acquisition					19,875	0	0
Net cash flows provided by (used in) investing activities					391,762	161,998	117,530
Cash flows used in financing activities
Issuance of common shares					24,823	2,305	31,884
Issuance of Series C, non-cumulative preferred shares					222,963	0	0
Redemption of Series A, non-cumulative preferred shares					(200,000)	0	0
Offering and registration costs paid					(617)	0	0
Bridge facility costs paid					0	(4,750)	0
Repurchase of common shares					0	0	(14,584)
Settlement of restricted shares					(14,535)	(4,039)	(3,001)
Repayments of debt					(198,500)	0	0
Dividends paid on preferred shares					(32,750)	(32,750)	(32,750)
Dividends paid on common shares					(78,473)	(60,524)	(55,906)
Net cash flows used in financing activities					(277,089)	(99,758)	(74,357)
Net increase (decrease) in cash and cash equivalents					2,966	(6,277)	(3,566)
Cash and cash equivalents, beginning of year				$ 240	240	6,517	10,083
Cash and cash equivalents, end of year	$ 3,206				$ 3,206	$ 240	$ 6,517

Schedule III Supplementary I127

Schedule III Supplementary Insurance Information (Supplementary Insurance Information) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs		$ 255,501	$ 207,368	$ 186,027
Reserve for Losses and Loss Expenses		4,510,415	3,846,859	4,002,259
Unearned Premiums		1,789,148	1,254,519	1,018,851
Net Premiums Earned		1,978,453	1,863,978	2,016,484
Net Investment Income	[1]	113,826	131,543	166,216
Net Losses and Loss Expenses		917,108	970,162	1,219,684
Amortization of Deferred Acquisition Costs		347,885	319,513	304,430
Other Operating Expenses	[2]	259,791	247,387	236,873
Net Premiums Written		1,950,470	1,934,206	2,048,933
Reinsurance
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs		197,285	172,787	155,932
Reserve for Losses and Loss Expenses		2,003,054	1,723,087	1,843,369
Unearned Premiums		886,996	611,740	566,738
Net Premiums Earned		1,153,901	1,030,066	1,070,010
Net Investment Income	[1]	0	0	0
Net Losses and Loss Expenses		413,547	375,601	445,259
Amortization of Deferred Acquisition Costs		267,633	254,145	239,652
Other Operating Expenses	[2]	119,779	98,912	100,285
Net Premiums Written		1,070,097	1,073,800	1,116,423
Insurance
Supplementary Insurance Information, by Segment [Line Items]
Deferred Acquisition Costs		58,216	34,581	30,095
Reserve for Losses and Loss Expenses		2,507,361	2,123,772	2,158,890
Unearned Premiums		902,152	642,779	452,113
Net Premiums Earned		824,552	833,912	946,474
Net Investment Income	[1]	0	0	0
Net Losses and Loss Expenses		503,561	594,561	774,425
Amortization of Deferred Acquisition Costs		80,252	65,368	64,778
Other Operating Expenses	[2]	140,012	148,475	136,588
Net Premiums Written		$ 880,373	$ 860,406	$ 932,510
[1]	Because the Company does not manage its assets by segment, investment income is not allocated to the individual segments.
[2]	General and administrative expenses incurred by segments are allocated directly. Remaining general and administrative expenses not incurred by the segments are classified as corporate expenses and are not allocated to the individual business segments.

Schedule IV Reinsurance (Summar

Schedule IV Reinsurance (Summary Of Reinsurance) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross	$ 2,085,901	$ 1,716,128	$ 1,475,429
Ceded to Other Companies	1,370,391	959,870	616,311
Assumed from Other Companies	1,234,960	1,177,948	1,189,815
Net premiums written	1,950,470	1,934,206	2,048,933
Property and liability insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross	2,085,901	1,716,128	1,475,429
Ceded to Other Companies	1,370,391	959,870	616,311
Assumed from Other Companies	1,234,960	1,177,948	1,189,815
Net premiums written	$ 1,950,470	$ 1,934,206	$ 2,048,933
Percentage of Amount Assumed to Net	63.00%	61.00%	58.00%

Schedule VI Underwriters (Sched

Schedule VI Underwriters (Schedule Of Underwriters) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Deferred Acquisition Costs		$ 255,501	$ 207,368	$ 186,027
Reserve for Losses and Loss Expenses		4,510,415	3,846,859	4,002,259
Discount if any, Reserve for Losses and Loss Expenses		0	0	0
Unearned Premiums		1,789,148	1,254,519	1,018,851
Net Premiums Earned		1,978,453	1,863,978	2,016,484
Net Investment Income	[1]	113,826	131,543	166,216
Incurred related to Current year		1,160,572	1,203,977	1,442,076
Net Losses And Loss Expenses, Prior Year		(243,464)	(233,815)	(222,392)
Amortization of Deferred Acquisition Costs		347,885	319,513	304,430
Paid Losses and Loss Expenses		1,133,637	1,158,212	1,362,092
Net Premiums Written		1,950,470	1,934,206	2,048,933
Reinsurance
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Deferred Acquisition Costs		197,285	172,787	155,932
Reserve for Losses and Loss Expenses		2,003,054	1,723,087	1,843,369
Discount if any, Reserve for Losses and Loss Expenses		0	0	0
Unearned Premiums		886,996	611,740	566,738
Net Premiums Earned		1,153,901	1,030,066	1,070,010
Net Investment Income	[1]	0	0	0
Incurred related to Current year		575,010	528,846	633,748
Net Losses And Loss Expenses, Prior Year		161,463	153,245	188,489
Amortization of Deferred Acquisition Costs		267,633	254,145	239,652
Paid Losses and Loss Expenses		500,599	457,636	564,782
Net Premiums Written		1,070,097	1,073,800	1,116,423
Insurance
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Deferred Acquisition Costs		58,216	34,581	30,095
Reserve for Losses and Loss Expenses		2,507,361	2,123,772	2,158,890
Discount if any, Reserve for Losses and Loss Expenses		0	0	0
Unearned Premiums		902,152	642,779	452,113
Net Premiums Earned		824,552	833,912	946,474
Net Investment Income	[1]	0	0	0
Incurred related to Current year		585,562	675,131	808,328
Net Losses And Loss Expenses, Prior Year		82,001	80,570	33,903
Amortization of Deferred Acquisition Costs		80,252	65,368	64,778
Paid Losses and Loss Expenses		633,038	700,576	797,310
Net Premiums Written		$ 880,373	$ 860,406	$ 932,510
[1]	Because the Company does not manage its assets by segment, investment income is not allocated to the individual segments.