Endurance Specialty (ENH) 10-Q 7 Nov 16 2016 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 03, 2016
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Entity Registrant Name	Endurance Specialty Holdings Ltd.
Entity Central Index Key	1,179,755
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		67,603,885

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Fixed maturity investments, trading at fair value (amortized cost: $2,369,345 and $1,611,079 at September 30, 2016 and December 31, 2015, respectively)	$ 2,393,352	$ 1,587,160
Fixed maturity investments, available for sale at fair value (amortized cost: $3,525,682 and $4,361,997 at September 30, 2016 and December 31, 2015, respectively)	3,596,720	4,359,019
Short-term investments, trading at fair value (amortized cost: $226,437 and $394,096 at September 30, 2016 and December 31, 2015, respectively)	226,454	394,111
Short-term investments, available for sale at fair value (amortized cost: $34,934 and $25,657 at September 30, 2016 and December 31, 2015, respectively)	34,934	25,685
Equity securities, trading at fair value (cost: $22,978 and $15,290 at September 30, 2016 and December 31, 2015, respectively)	23,120	15,229
Equity securities, available for sale at fair value (cost: $468,176 and $542,429 at September 30, 2016 and December 31, 2015, respectively)	496,402	513,585
Other investments	679,007	872,617
Total investments	7,449,989	7,767,406
Cash and cash equivalents	1,323,110	1,177,750
Securities pledged under repurchase agreements	124,303	0
Premiums receivable, net	2,264,651	1,376,328
Insurance and reinsurance balances receivable	127,849	102,403
Deferred acquisition costs	311,894	255,501
Prepaid reinsurance premiums	825,913	498,574
Reinsurance recoverable on unpaid losses	1,124,976	907,944
Reinsurance recoverable on paid losses	311,324	288,026
Accrued investment income	30,073	30,213
Goodwill and intangible assets	489,522	553,960
Deferred tax asset	57,050	64,164
Net receivable on sales of investments	106,305	31,873
Other assets	283,474	187,383
Total assets	14,830,433	13,241,525
LIABILITIES
Reserve for losses and loss expenses	4,807,868	4,510,415
Reserve for unearned premiums	2,348,566	1,789,148
Reinsurance balances payable	1,018,618	661,213
Payable under repurchase agreements	120,997	0
Debt	705,179	717,650
Net payable on purchases of investments	203,592	63,442
Deferred tax liability	12,815	17,315
Other liabilities	389,561	358,270
Total liabilities	9,607,196	8,117,453
Commitments and contingent liabilities
SHAREHOLDERS' EQUITY
Preferred shares, total liquidation preference $230,000 (2015 - $460,000)	9	9,209
Common shares, ordinary - 67,594,088 issued and outstanding (2015 - 66,797,991)	67,594	66,798
Additional paid-in capital	1,953,507	2,145,836
Accumulated other comprehensive income (loss)	27,993	(46,634)
Retained earnings	2,917,141	2,681,053
Total shareholders' equity available to Endurance Holdings	4,966,244	4,856,262
Non-controlling interests	256,993	267,810
Total shareholders' equity	5,223,237	5,124,072
Total liabilities and shareholders' equity	$ 14,830,433	$ 13,241,525

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Investments [Abstract]
Fixed maturity investments, trading, amortized cost	$ 2,369,345	$ 1,611,079
Fixed maturity investments, available for sale, amortized cost	3,525,682	4,361,997
Short-term investments, trading, amortized cost	226,437	394,096
Short-term investments, available for sale, amortized cost	34,934	25,657
Equity securities, trading, cost	22,978	15,290
Equity securities, available for sale, cost	468,176	542,429
Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock, aggregate liquidation preference	$ 230,000	$ 460,000
Common stock, shares issued	67,594,088	66,797,991
Common stock, shares outstanding	67,594,088	66,797,991

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements Of Income And Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues
Gross premiums written	$ 760,687	$ 642,597	$ 3,509,294	$ 2,805,213
Ceded premiums written	(411,701)	(305,907)	(1,503,698)	(1,144,486)
Net premiums written	348,986	336,690	2,005,596	1,660,727
Change in unearned premiums	261,170	220,313	(242,641)	(255,730)
Net premiums earned	610,156	557,003	1,762,955	1,404,997
Net investment income	62,236	16,533	117,394	90,646
Net realized and unrealized gains	13,405	5,029	33,539	32,898
Net impairment losses recognized in earnings	(183)	(38)	(10,647)	(1,111)
Other underwriting (loss) income	(466)	227	(1,980)	4,022
Total revenues	685,148	578,754	1,901,261	1,531,452
Expenses
Net losses and loss expenses	331,462	263,993	950,902	675,051
Acquisition expenses	121,391	90,457	337,194	257,521
General and administrative expenses	67,738	60,793	195,042	170,648
Corporate expenses	11,952	74,308	35,553	99,210
Amortization of intangibles	21,154	11,318	63,471	14,496
Net foreign exchange (gains) losses	(18,576)	8,621	(63,056)	29,154
Interest expense	10,826	12,324	33,053	30,445
Total expenses	545,947	521,814	1,552,159	1,276,525
Income before income taxes	139,201	56,940	349,102	254,927
Income tax benefit (expense)	199	(2,410)	2,570	(7,712)
Net income	139,400	54,530	351,672	247,215
Net income attributable to non-controlling interests	(5,679)	(2,707)	(18,456)	(2,707)
Net income available to Endurance Holdings	133,721	51,823	333,216	244,508
Preferred dividends	(3,651)	(8,188)	(20,147)	(24,564)
Net income available to Endurance Holdings' common and participating common shareholders	130,070	43,635	313,069	219,944
Comprehensive income
Net income	139,400	54,530	351,672	247,215
Other comprehensive income (loss)
Net unrealized holding gains (losses) on investments arising during the period (net of other-than-temporary impairment losses recognized in other comprehensive income (loss), reclassification adjustment and applicable deferred income taxes of ($18,464) and $1,323 for the nine months ended September 30, 2016 and 2015, respectively)	21,136	(29,906)	137,731	(72,396)
Foreign currency translation adjustments	(13,114)	(15,625)	(63,170)	(12,920)
Reclassification adjustment for net losses on derivative designated as cash flow hedge included in net income	22	22	66	66
Other comprehensive income (loss)	8,044	(45,509)	74,627	(85,250)
Comprehensive income	147,444	9,021	426,299	161,965
Comprehensive income attributable to non-controlling interests	(5,679)	(2,707)	(18,456)	(2,707)
Comprehensive income attributable to Endurance Holdings	$ 141,765	$ 6,314	$ 407,843	$ 159,258
Per share data
Basic earnings per common share	$ 1.93	$ 0.73	$ 4.65	$ 4.41
Diluted earnings per common share	1.92	0.73	4.64	4.39
Dividend per common share	$ 0.38	$ 0.35	$ 1.14	$ 1.05

Unaudited Condensed Consolidat5

Unaudited Condensed Consolidated Statements Of Income And Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Other comprehensive income (loss), net unrealized holding gains on investments arising during the period, tax	$ (18,464)	$ 1,323

Unaudited Condensed Consolidat6

Unaudited Condensed Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Cumulative Foreign Currency Translation Adjustments [Member]	Unrealized Holding Gains On Investments, Net Of Deferred Taxes [Member]	Accumulated Derivative Loss On Cash Flow Hedging Instruments [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Balance, beginning of period at Dec. 31, 2014		$ 17,200	$ 44,765	$ 598,226	$ (7,628)	$ 86,100	$ (1,766)		$ 2,448,285
Redemption of Series B, non-cumulative preferred shares		0		0
Issuance of common shares, net of forfeitures			21,842	1,474,432
Settlement of equity awards				(10,494)
Stock-based compensation expense				46,283
Foreign currency translation adjustments	$ (12,920)				(12,920)
Net unrealized holding gains (losses) arising during the period, net of other-than-temporary impairment losses and reclassification adjustment	(72,396)					(72,396)
Net change from current period hedging transactions, net of reclassification adjustment							66
Net income	247,215								247,215
Net income attributable to non-controlling interests	2,707								(2,707)
Dividends on preferred shares	(24,564)								(24,564)
Dividends on common shares									(55,069)
Balance, end of period at Sep. 30, 2015	4,796,870	17,200	66,607	2,108,447	(20,548)	13,704	(1,700)	$ (8,544)	2,613,160
Non-controlling interests	259,474
Total shareholders' equity	5,056,344
Non-controlling interests	267,810
Total shareholders' equity	5,124,072
Balance, beginning of period at Dec. 31, 2015	4,856,262	9,209	66,798	2,145,836	(32,318)	(12,638)	(1,678)		2,681,053
Redemption of Series B, non-cumulative preferred shares		(9,200)		(219,741)
Issuance of common shares, net of forfeitures			796	10,218
Settlement of equity awards				(10,842)
Stock-based compensation expense				28,036
Foreign currency translation adjustments	(63,170)				(63,170)
Net unrealized holding gains (losses) arising during the period, net of other-than-temporary impairment losses and reclassification adjustment	137,731					137,731
Net change from current period hedging transactions, net of reclassification adjustment							66
Net income	351,672								351,672
Net income attributable to non-controlling interests	18,456								(18,456)
Dividends on preferred shares	(20,147)								(20,147)
Dividends on common shares									(76,981)
Balance, end of period at Sep. 30, 2016	4,966,244	9	67,594	1,953,507	(95,488)	125,093	(1,612)	27,993	2,917,141
Non-controlling interests	259,851
Foreign currency translation adjustments	(13,114)
Net unrealized holding gains (losses) arising during the period, net of other-than-temporary impairment losses and reclassification adjustment	21,136
Net income	139,400
Net income attributable to non-controlling interests	5,679
Dividends on preferred shares	(3,651)
Balance, end of period at Sep. 30, 2016	4,966,244	$ 9	$ 67,594	$ 1,953,507	$ (95,488)	$ 125,093	$ (1,612)	$ 27,993	$ 2,917,141
Non-controlling interests	256,993
Total shareholders' equity	$ 5,223,237

Unaudited Condensed Consolidat7

Unaudited Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows provided by (used in) operating activities
Net income	$ 351,672	$ 247,215
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Amortization of net premium on investments	28,097	34,116
Amortization of other intangibles and depreciation	78,551	29,291
Net realized and unrealized gains	(33,539)	(32,898)
Net impairment losses recognized in earnings	10,647	1,111
Deferred taxes	(14,876)	3,437
Stock-based compensation expense	28,036	46,283
Equity in losses of other investments	201	1,758
Premiums receivable, net	(888,323)	(845,891)
Insurance and reinsurance balances receivable	(25,446)	21,085
Deferred acquisition costs	(56,393)	(75,607)
Prepaid reinsurance premiums	(327,339)	(227,337)
Reinsurance recoverable on unpaid losses	(217,032)	(119,269)
Reinsurance recoverable on paid losses	(23,298)	63,141
Accrued investment income	140	4,996
Other assets	(2,575)	(319)
Reserve for losses and loss expenses	297,453	(77,954)
Reserve for unearned premiums	559,418	477,440
Reinsurance balances payable	357,405	338,279
Other liabilities	(63,412)	37,094
Net cash flows provided by (used in) operating activities	59,387	(74,029)
Cash flows provided by investing activities
Proceeds from sales and maturities of trading investments	2,059,959	103,450
Proceeds from sales and maturities of available for sale investments	3,150,250	4,201,152
Proceeds from the redemption of other investments	246,349	124,801
Purchases of trading investments	(2,643,730)	(286,416)
Purchases of available for sale investments	(2,385,309)	(4,047,359)
Purchases of other investments	(50,585)	(116,988)
Net settlements of other assets and other liabilities	(33,620)	17,301
Purchases of fixed assets	(10,999)	(18,053)
Net cash (paid) received upon subsidiary acquisition	(7)	675,310
Net cash flows provided by investing activities	332,308	653,198
Cash flows used in financing activities
Issuance of common shares	9,550	24,378
Redemption of Series B, non-cumulative preferred shares	(230,000)	0
Net distributions to non-controlling interests	(27,517)	0
Settlement of equity awards	(10,842)	(10,494)
Offering and registration costs paid	(319)	0
Proceeds from issuance of repurchase agreements	120,997	0
Proceeds from issuance of debt	537	791
Repayments of debt	(13,645)	(794)
Dividends on preferred shares	(20,147)	(24,564)
Dividends on common shares	(76,934)	(54,959)
Net cash flows used in financing activities	(248,320)	(65,642)
Effect of exchange rate changes on cash and cash equivalents	1,985	(16,002)
Net increase in cash and cash equivalents	145,360	497,525
Cash and cash equivalents, beginning of period	1,177,750	745,472
Cash and cash equivalents, end of period	$ 1,323,110	$ 1,242,997

General

General	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	1. General Endurance Specialty Holdings Ltd. ("Endurance Holdings" and together with its subsidiaries, the "Company") was organized as a Bermuda holding company on June 27, 2002. Endurance Holdings writes specialty lines of insurance and reinsurance on a global basis through its wholly-owned operating subsidiaries. In addition, as part of its collateralized reinsurance and third party asset management operations, Endurance Holdings and Endurance Specialty Insurance Ltd. ("Endurance Bermuda") together own 33.3% of Blue Capital Reinsurance Holdings Ltd. ("BCRH"), and Endurance Bermuda owns 25.2% of Blue Capital Global Reinsurance Fund Limited ("BCGR"). BCRH is a Bermuda-based exempted limited liability holding company managed by Blue Capital Management Ltd. ("BCML"), a wholly-owned subsidiary of the Company. BCRH 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. BCGR serves as the feeder fund for the Blue Capital Global Reinsurance SA-I 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	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	2. Summary of significant accounting policies The accompanying consolidated financial statements have been prepared on the basis of accounting principles generally accepted in the United States ("U.S. GAAP") for interim financial information and with the instructions to the Quarterly Report on Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Results for the three and nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 . The consolidated financial statements include the accounts of Endurance Holdings, its wholly-owned subsidiaries, and BCRH and the BCGR Cell. All intercompany transactions and balances have been eliminated in consolidation. Management is required to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying disclosures. Actual results could differ from those estimates. Among other matters, significant estimates and assumptions are used to record premiums written and ceded, to record the fair value of investments and to record reserves for losses and loss expenses and contingencies. Estimates and assumptions are periodically reviewed and the effects of revisions are recorded in the consolidated financial statements in the period that they are determined to be necessary. The balance sheet at December 31, 2015 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These consolidated financial statements and notes thereto should be read in conjunction with the consolidated financial statements and notes thereto for the year ended December 31, 2015 contained in Endurance Holdings' Annual Report on Form 10-K for the fiscal year ended December 31, 2015 (the " 2015 Form 10-K"). Certain comparative information has been reclassified to conform to current year presentation. There were no material changes in the Company's significant accounting and reporting policies subsequent to the filing of the 2015 Form 10-K with the exception of the additions to the Company's accounting policies described below relating to the Company's investment repurchase agreements in the current quarter. (a) Investments The Company has entered into investment repurchase agreements, whereby the Company sells securities and repurchases them at a future date for a predetermined price. These investment repurchase agreements are accounted for as secured borrowings and are recorded at the contractual repurchase price plus accrued interest. The securities to be repurchased are the same, or substantially the same, as those sold. The fair value of the underlying securities is included in securities pledged under repurchase agreements in the Consolidated Balance Sheets. The use of the cash received by the Company from the counterparty pursuant to the repurchase agreement is not restricted. 2. Summary of significant accounting policies, cont'd. (a) Investments, cont'd. The obligation to return the cash is included in payable under repurchase agreements in the Consolidated Balance Sheets. In these repurchase transactions, the securities sold by the Company (pledged collateral) may be sold or repledged by the counterparties with whom the repurchase agreement is executed. (b) 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. This guidance is not expected to have a material impact on the Company's Unaudited Condensed 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 became effective for public business entities for annual and interim periods beginning after December 15, 2015. Early adoption was permitted. The Company adopted ASU 2015-02 effective January 1, 2016 and it did not have a material impact on the Company's Unaudited Condensed 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 became effective for public business entities in interim and annual periods beginning after December 15, 2015. Early adoption was permitted. The Company adopted ASU 2015-16 effective January 1, 2016 and it did not have a material impact on the Company's Unaudited Condensed Consolidated Financial Statements. In January 2016, the FASB issued ASU 2016-01, "Financial Instruments - Overall, Recognition and Measurement of Financial Assets and Financial Liabilities" ("ASU 2016-01"). ASU 2016-01 requires entities to measure certain equity investments at fair value and recognize any changes in fair value in net income unless the investments qualify for a practicability exception. For financial liabilities measured using the fair value option, entities will need to present any change in fair value caused by a change in instrument-specific credit risk separately in other comprehensive income. ASU 2016-01 also changes certain disclosure requirements and other aspects of current U.S. GAAP. ASU 2016-01 is effective for public business entities for annual and interim periods beginning after December 15, 2017. Early adoption is not permitted, except for certain provisions. ASU 2016-01 should be applied by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. The amendments related to equity securities without readily determinable fair values (including disclosure requirements) should be applied prospectively. The Company is currently evaluating the impact of this guidance on its Unaudited Condensed Consolidated Financial Statements. 2. Summary of significant accounting policies, cont'd. (b) Recent accounting pronouncements, cont'd. In February 2016, the FASB issued ASU 2016-02, "Leases" ("ASU 2016-02"). The objective of ASU 2016-02 is to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. ASU 2016-02 is effective for public business entities for annual and interim periods beginning after December 15, 2018. Early adoption is permitted. ASU 2016-02 must be applied using a modified retrospective approach. The Company is currently evaluating the impact of this guidance on its Unaudited Condensed Consolidated Financial Statements. In March 2016, the FASB issued ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting" ("ASU 2016-09"). ASU 2016-09 will change how companies account for certain aspects of share-based payments to employees. Entities will be required to recognize the income tax effects of awards in the income statement when the awards vest or are settled. The guidance also changes employers' accounting for an employee's use of shares to satisfy the employer's statutory income tax withholding obligation, and accounting for forfeitures. ASU 2016-09 is effective for public business entities for annual and interim periods beginning after December 15, 2016. Early adoption is permitted. This guidance is not expected to have a material impact on the Company's Unaudited Condensed Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses - Measurement of Credit Losses on Financial Instruments" ("ASU 2016-13"). ASU 2016-13 will change how companies measure credit losses for most financial assets and certain other instruments that aren't measured at fair value through net income. The standard will replace today's "incurred loss" approach with an "expected loss" model for instruments measured at amortized cost and require entities to record allowances for available-for-sale debt securities rather than reduce the carrying amount, as they do today under the other-than-temporary impairment model. ASU 2016-13 is effective for public business entities for annual and interim periods beginning after December 15, 2019. Early adoption is permitted for all entities for annual periods beginning after December 15, 2018, and interim periods therein. The Company is currently evaluating the impact of this guidance on its Unaudited Condensed Consolidated Financial Statements.

Investments

Investments	9 Months Ended
	Sep. 30, 2016
Investments [Abstract]
Investments	3. Investments Net Investment Income The components of net investment income for the three and nine months ended September 30, 2016 and 2015 are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Fixed income investments $ 41,078 $ 36,204 $ 118,382 $ 96,145 Equity investments 1,906 1,748 8,754 5,200 Other investments 22,804 (17,716 ) (201 ) (1,758 ) Cash and cash equivalents 392 515 2,043 2,108 $ 66,180 $ 20,751 $ 128,978 $ 101,695 Investment expenses (3,944 ) (4,218 ) (11,584 ) (11,049 ) Net investment income $ 62,236 $ 16,533 $ 117,394 $ 90,646 3. Investments, cont'd. Contractual maturities of the Company's fixed maturity and short-term investments are shown below as of September 30, 2016 and December 31, 2015 . 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. September 30, 2016 December 31, 2015 Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 508,899 $ 509,417 $ 622,070 $ 622,248 Due after one year through five years 2,005,903 2,031,970 2,005,456 1,995,502 Due after five years through ten years 736,318 757,530 683,147 676,932 Due after ten years 45,303 48,537 33,168 34,651 Residential mortgage-backed securities 1,299,811 1,329,069 1,301,083 1,311,373 Commercial mortgage-backed securities 702,760 714,142 817,570 812,886 Collateralized loan and debt obligations 392,578 393,922 419,795 405,128 Asset-backed securities 464,826 466,873 510,540 507,255 Total $ 6,156,398 $ 6,251,460 $ 6,392,829 $ 6,365,975 The following table summarizes the fair value of the fixed maturity investments, short-term investments and equity securities classified as trading at September 30, 2016 and December 31, 2015 : September 30, 2016 December 31, 2015 Fixed maturity investments U.S. government and agencies securities $ 396,468 $ 319,674 U.S. state and municipal securities 5,203 5,559 Foreign government securities 128,786 49,861 Government guaranteed corporate securities 31,526 38,201 Corporate securities 951,523 532,192 Residential mortgage-backed securities 391,704 258,574 Commercial mortgage-backed securities 181,569 127,124 Collateralized loan and debt obligations (1) 93,307 103,219 Asset-backed securities 213,266 152,756 Total fixed maturity investments 2,393,352 1,587,160 Short-term investments 226,454 394,111 Total fixed income investments $ 2,619,806 $ 1,981,271 Equity securities Equity investments $ 117 $ 48 Preferred equity investments 5,966 553 Short-term fixed income fund 17,037 14,628 Total equity securities $ 23,120 $ 15,229 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $3.6 million and $38.5 million at September 30, 2016 and December 31, 2015 , respectively. In addition to the Company's fixed maturity, short-term and equity securities, the Company invests in alternative funds and specialty funds. The Company's alternative funds and specialty funds are recorded on the Company's Condensed Consolidated Balance Sheets as "other investments." At September 30, 2016 and December 31, 2015 , the Company had invested, net of capital returned, a total of $569.2 million and $737.1 million , respectively, in other investments. At September 30, 2016 and December 31, 2015 , the carrying value of other investments was $679.0 million and $872.6 million , respectively. 3. Investments, cont'd. The following table summarizes the composition, unfunded commitments and redemption restrictions of other investments as of September 30, 2016 and December 31, 2015 : September 30, 2016 Market Value Unfunded Commitments Ineligible for Redemption over next 12 months Alternative funds Hedge funds $ 576,291 $ — $ 97,334 Private investment funds 76,665 95,846 76,665 Other investment funds 26,051 — 25,575 Total alternative funds 679,007 95,846 199,574 Total other investments $ 679,007 $ 95,846 $ 199,574 December 31, 2015 Market Value Unfunded Ineligible for Alternative funds Hedge funds $ 704,966 $ — $ 57,876 Private investment funds 80,690 102,070 80,690 Other investment funds 23,465 — 24,958 Total alternative funds 809,121 102,070 163,524 Specialty funds High yield loan funds 63,496 30,000 — Total specialty funds 63,496 30,000 — Total other investments $ 872,617 $ 132,070 $ 163,524 Hedge funds – The redemption frequency of the hedge funds in which the Company invests range from monthly to biennially with notice periods from 30 to 180 days. Over one year, it is estimated that the Company can liquidate approximately 83.1% of its 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 fund 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 liquidation of or distribution of earnings from 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 equity funds. Other investment funds – Other investment funds includes funds on deposit with Lloyd's of London ("Lloyd's"), which are restricted, and the Company's investment in BCGR, which represents the net asset or 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 is monthly with notice periods from 30 to 60 days. 3. Investments, cont'd. Net Realized and Unrealized Gains Realized 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 (losses) on trading securities, and the change in the fair value of investment-related derivative financial instruments for the three and nine months ended September 30, 2016 and 2015 is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Gross realized gains on investment sales $ 11,072 $ 20,107 $ 35,776 $ 57,420 Gross realized losses on investment sales (3,365 ) (8,236 ) (50,537 ) (18,190 ) Net unrealized gains (losses) on trading securities 6,153 (5,037 ) 48,229 (5,037 ) Change in fair value of investment-related derivative financial instruments (1) (455 ) (1,805 ) 71 (1,295 ) Net realized and unrealized gains $ 13,405 $ 5,029 $ 33,539 $ 32,898 (1) For additional information on the Company's derivative financial instruments, see Note 7, Derivatives. Unrealized Gains and Losses The Company classifies some of its investments in fixed maturity investments, short-term investments and equity securities 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 September 30, 2016 and December 31, 2015 are as follows: September 30, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity investments U.S. government and agencies securities $ 338,564 $ 8,551 $ (79 ) $ 347,036 U.S. state and municipal securities 10,804 125 (157 ) 10,772 Foreign government securities 82,096 2,196 (2 ) 84,290 Government guaranteed corporate securities 9,613 298 — 9,911 Corporate securities 1,096,722 24,174 (345 ) 1,120,551 Residential mortgage-backed securities 912,540 25,283 (458 ) 937,365 Commercial mortgage-backed securities 523,921 11,920 (3,268 ) 532,573 Collateralized loan and debt obligations (1) 298,990 2,239 (614 ) 300,615 Asset-backed securities 252,432 1,860 (685 ) 253,607 Total fixed maturity investments 3,525,682 76,646 (5,608 ) 3,596,720 Short-term investments 34,934 — — 34,934 Total fixed income investments $ 3,560,616 $ 76,646 $ (5,608 ) $ 3,631,654 Equity securities Equity investments $ 330,971 $ 22,347 $ (2,068 ) $ 351,250 Emerging market debt funds 83,668 4,057 — 87,725 Convertible funds 46,331 2,313 — 48,644 Preferred equity investments 7,078 1,684 (110 ) 8,652 Short-term fixed income fund 128 3 — 131 Total equity securities $ 468,176 $ 30,404 $ (2,178 ) $ 496,402 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $3.2 million . 3. Investments, cont'd. 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 funds 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 . 3. Investments, cont'd. The following tables summarize, for all available for sale securities in an unrealized loss position at September 30, 2016 and December 31, 2015 , 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 September 30, 2016 Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Fixed maturity investments U.S. government and agencies securities $ (79 ) $ 24,932 $ — $ — $ (79 ) $ 24,932 U.S. state and municipal securities (74 ) 5,697 (83 ) 2,250 (157 ) 7,947 Foreign government securities (1 ) 1,349 (1 ) 549 (2 ) 1,898 Corporate securities (161 ) 65,619 (184 ) 19,814 (345 ) 85,433 Residential mortgage-backed securities (188 ) 29,949 (270 ) 36,070 (458 ) 66,019 Commercial mortgage-backed securities (1,356 ) 118,481 (1,912 ) 63,554 (3,268 ) 182,035 Collateralized loan and debt obligations (240 ) 18,373 (374 ) 52,084 (614 ) 70,457 Asset-backed securities (263 ) 49,423 (422 ) 31,248 (685 ) 80,671 Total fixed income investments $ (2,362 ) $ 313,823 $ (3,246 ) $ 205,569 $ (5,608 ) $ 519,392 Equity securities Equity investments $ (1,284 ) $ 15,453 $ (784 ) $ 14,222 $ (2,068 ) $ 29,675 Preferred equity investments (95 ) 1,614 (15 ) 235 (110 ) 1,849 Total equity securities $ (1,379 ) $ 17,067 $ (799 ) $ 14,457 $ (2,178 ) $ 31,524 (1) Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive income at September 30, 2016 . As of September 30, 2016 , 478 available for sale securities were in an unrealized loss position aggregating $7.8 million . Of those, 210 securities with aggregated unrealized losses of $4.0 million had been in a continuous unrealized loss position for twelve months or greater. 3. Investments, cont'd. 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 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 had been in a continuous unrealized loss position for twelve months or greater. 3. Investments, cont'd. The decrease in gross unrealized losses on the Company's available for sale fixed income investments at September 30, 2016 compared to December 31, 2015 was primarily due to a decrease in interest rates during the nine months ended September 30, 2016 . At September 30, 2016 , the Company did not have the intent to sell any of the remaining fixed income investments in an unrealized loss position and determined that it was unlikely that the Company would be required to sell those securities in an unrealized loss position. During the nine months ended September 30, 2016 , the Company impaired certain equity securities that were in an unrealized loss position for more than twelve consecutive months. The Company recognized in earnings total other-than-temporary impairments of $0.2 million and $10.6 million for the three and nine months ended September 30, 2016 . Other Investments The Company is involved in the normal course of business with VIEs 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 reassesses its VIE determination with respect to an entity on an ongoing basis. The Company determined that it was not the primary beneficiary for any of these investments as of September 30, 2016 . 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 Condensed Consolidated Balance Sheets and any unfunded investment commitments. Collateralized Reinsurance Entities As of September 30, 2016 , Endurance Holdings and Endurance Bermuda together owned 33.3% of BCRH's common shares. BCRH is considered a VIE under U.S. GAAP due to service agreements for investment management, underwriting and insurance management and administrative services between BCRH and BCML, and the economic penalty to terminate the service agreements by BCRH. The Company has determined that it is BCRH's primary beneficiary due to its ability to direct the activities of BCRH through BCML along with its economic interest in BCRH. As a result, the Company fully consolidates the assets, liabilities and operations of BCRH and its subsidiaries within its Unaudited Condensed 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 Unaudited Condensed 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 September 30, 2016 , Endurance Bermuda owned 25.2% 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 Unaudited Condensed Consolidated Financial Statements. However, the BCGR Cell and Blue Water Re Ltd. ("Blue Water Re"), the Company's wholly-owned Bermuda-based special purpose insurance vehicle, are considered VIEs under U.S. GAAP due to service agreements for investment management, underwriting and insurance management and administrative services between Blue Water Re and BCML. The Company has determined that it is the primary beneficiary of these entities due to its ability to direct the activities of Blue Water Re and the BCGR Cell along with its economic interest in these entities. Therefore, as funds held in BCGR are invested in the BCGR Cell, and ultimately into Blue Water Re, they are included in the Company's Unaudited Condensed Consolidated Financial Statements. Conversely, as funds previously invested by BCGR and the BCGR Cell into Blue Water Re are returned to BCGR, they are no longer included in the Company's Unaudited Condensed Consolidated Financial Statements. The interests in the BCGR Cell and Blue Water Re that the Company fully consolidates that are attributable to third-party investors are reported within the Company's Unaudited Condensed 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. 3. Investments, cont'd. The following table summarizes the movements in the non-redeemable non-controlling interests balance during the three and nine months ended September 30, 2016 and 2015 : Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Non-controlling interests, beginning of period $ 259,851 $ 258,529 $ 267,810 $ 258,529 Income attributable to third-party investments in the BCGR Cell 3,453 821 11,603 821 Income attributable to third-party investments in BCRH 2,226 1,886 6,853 1,886 Net income attributable to non-controlling interests 5,679 2,707 18,456 2,707 Net preferred share redemptions attributable to third-party investments in the BCGR Cell (1) (6,800 ) — (16,807 ) — Net investments attributable to third-parties in BCRH 20 (7 ) 53 (7 ) Net change in third-party investments in non-controlling interests (6,780 ) (7 ) (16,754 ) (7 ) Dividends declared by BCRH attributable to non-controlling interests (1,757 ) (1,755 ) (12,519 ) (1,755 ) Non-controlling interests, end of period $ 256,993 $ 259,474 $ 256,993 $ 259,474 (1) The redemption from the BCGR Cell during the three and nine months ended September 30, 2016 was required to fund expenses, repay debt and fund dividends by BCGR.

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurement	4. 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. The Company uses models that include unobservable inputs to price its corporate bank loan portfolio. As such, the fair values of the corporate bank loans are generally classified in Level 3. • 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 credits for like or similar securities. The Company generally classifies the fair values of its equity securities in Level 1 or 2. 4. Fair value measurement, cont'd. • Structured securities including agency and non-agency, residential and commercial mortgage-backed securities, 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. • Securities pledged under repurchase agreements - These securities have been sold under a repurchase agreement and consist of U.S. government and agencies and residential mortgage-backed securities. Please refer to the pricing methods used for these types of securities. • 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 and energy 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 7.0% Senior Notes due July 15, 2034, the 4.7% Senior Notes due October 15, 2022 (together, the "Senior Notes") and the Trust Preferred Securities. The fair values of the Senior Notes were obtained from a third party pricing service and pricing was based on the spread above the risk-free yield curve. The fair values of the Trust Preferred Securities were 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. 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, payable under repurchase agreements, the amount outstanding under the BCRH Credit Agreement (as defined in Note 10) and other financial instruments not described above approximated their fair values at September 30, 2016 and December 31, 2015 . Transfers between levels are assumed to occur at the end of each period. 4. Fair value measurement, cont'd. The following table sets forth the Company's fixed maturity investments, equity securities, short-term investments, securities pledged under repurchase agreements, other assets and liabilities and debt categorized by the level within the hierarchy in which the fair value measurements fall at September 30, 2016 : Fair Value Measurements at September 30, 2016 Total at September 30, 2016 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 $ 743,504 $ 51,668 $ 691,836 $ — U.S. state and municipal securities 15,975 — 15,975 — Foreign government securities 213,076 — 213,076 — Government guaranteed corporate securities 41,437 — 41,437 — Corporate securities 2,072,074 — 1,893,278 178,796 Residential mortgage-backed securities 1,329,069 — 1,329,069 — Commercial mortgage-backed securities 714,142 — 712,448 1,694 Collateralized loan and debt obligations 393,922 — 393,865 57 Asset-backed securities 466,873 — 466,873 — Total fixed maturity investments 5,990,072 51,668 5,757,857 180,547 Equity securities Equity investments 351,367 163,412 187,955 — Emerging market debt funds 87,725 — 87,725 — Convertible funds 48,644 — 48,644 — Preferred equity investments 14,618 — 14,618 — Short-term fixed income fund 17,168 17,168 — — Total equity securities 519,522 180,580 338,942 — Short-term investments 261,388 — 261,388 — Securities pledged under repurchase agreements (see Note 10) 124,303 — 124,303 — Other assets (see Note 7) 159,273 2,331 124,373 32,569 Total assets $ 7,054,558 $ 234,579 $ 6,606,863 $ 213,116 Liabilities Other liabilities (see Note 7) $ 97,958 $ 2,942 $ 67,075 $ 27,941 Debt 799,393 — 799,393 — Total liabilities $ 897,351 $ 2,942 $ 866,468 $ 27,941 During the three months ended September 30, 2016 , $62.9 million of primarily corporate securities were transferred into Level 3 as no observable inputs were available. No securities were transferred out of Level 3 to Level 2 during the period. During the three months ended September 30, 2015 , $128.9 million of primarily of corporate securities were transferred into Level 3 as no observable inputs were available. No securities were transferred out of Level 3 to Level 2 during the period. During the nine months ended September 30, 2016 , $79.3 million of primarily corporate securities were transferred into Level 3 as no observable inputs were available. $5.5 million of primarily corporate securities were transferred out of Level 3 to Level 2 during the period as market activity for these securities increased and observable inputs became available. 4. Fair value measurement, cont'd. During the nine months ended September 30, 2015 , $130.9 million of primarily of corporate securities were transferred into Level 3 as no observable inputs were available, and $9.2 million of primarily asset-backed and commercial mortgage-backed securities were transferred out of Level 3 to Level 2 during the period as market activity for these securities increased and observable inputs became available. 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 7) 68,892 4 27,385 41,503 Total assets $ 6,963,681 $ 312,831 $ 6,496,894 $ 153,956 Liabilities Other liabilities (see Note 7) $ 46,088 $ — $ 4,059 $ 42,029 Debt 737,974 — 737,974 — Total liabilities $ 784,062 $ — $ 742,033 $ 42,029 Level 3 assets represented 3.0% and 2.2% of the Company's total fair valued assets at September 30, 2016 and December 31, 2015 , respectively. Level 3 securities are primarily comprised of corporate securities, commercial mortgage-backed securities, collateralized loan and debt obligations, and weather derivatives. There were no material changes in the Company's valuation techniques for the nine months ended September 30, 2016 . 4. Fair value measurement, cont'd. Other assets and other liabilities measured at fair value and classified as Level 3 at September 30, 2016 include assets of $32.6 million (December 31, 2015 - $41.5 million ) and liabilities of $27.9 million (December 31, 2015 - $42.0 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, contractual limits, temperature, rainfall, windspeed, wave height, snow fall, cyclone category; • Unobservable inputs: correlation, composite weather variable; and • Both observable and unobservable: forward commodity price. The Company's weather curves are determined by taking the average payouts for each transaction within its portfolio utilizing de-trended 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 inputs that are unobservable, such trades are 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. 4. Fair value measurement, cont'd. Below is a summary of quantitative information regarding the significant inputs used in determining the fair value of the net weather and energy related derivative assets and liabilities classified in Level 3 that are measured at fair value on a recurring basis at September 30, 2016 and December 31, 2015 : September 30, 2016 Fair Value (Level 3) Valuation Techniques Inputs Range Low High (Commodity curve in U.S. dollars in thousands) Net weather and energy related derivative assets $ 4,628 Historical Analysis and Simulation Correlation 0 1 Temperature -15F 115F Composite weather variable -25 deg. 45 deg. Rainfall 0" 2" Windspeed 0.01 m/s 25 m/s Wave height 0 m 25 m Commodity curve $ (1 ) $ 14 December 31, 2015 Fair Value (Level 3) Valuation Techniques Inputs Range Low High (Commodity curve in U.S. dollars in thousands) Net weather and energy related derivative liabilities $ 526 Historical Analysis and Simulation Correlation 0 1 Temperature -15F 115F Composite weather variable -25 deg. 45 deg. Rainfall 0" 2" Windspeed 0.01 m/s 25 m/s Snowfall 0" 18" Cyclone (category) 0 5 Commodity curve $ — $ 13 4. 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 three months ended September 30, 2016 and 2015 : Three Months Ended September 30, 2016 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of period $ 109,025 $ 34,357 $ 143,382 $ (21,549 ) Total realized and unrealized gains included in earnings 1,585 — 1,585 — Total realized and unrealized losses included in earnings (117 ) — (117 ) — Total income included in other underwriting (loss) income — 1,651 1,651 7,186 Total loss included in other underwriting (loss) income — (3,762 ) (3,762 ) (3,185 ) Change in unrealized gains included in other comprehensive income (loss) 60 — 60 — Change in unrealized losses included in other comprehensive income (loss) (46 ) — (46 ) — Purchases 15,004 — 15,004 — Issues — 9,378 9,378 (14,035 ) Sales (7,831 ) — (7,831 ) — Settlements — (9,055 ) (9,055 ) 3,642 Transfers into Level 3 62,867 — 62,867 — Transfers out of Level 3 — — — — Level 3, end of period $ 180,547 $ 32,569 $ 213,116 $ (27,941 ) Three Months Ended September 30, 2015 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of period $ 4,707 $ 23,691 $ 28,398 $ (22,184 ) Total realized and unrealized losses included in earnings (24 ) — (24 ) — Total income included in other underwriting (loss) income — 1,589 1,589 14,745 Total loss included in other underwriting (loss) income — (11,794 ) (11,794 ) (2,552 ) Change in unrealized gains included in other comprehensive income (loss) 85 — 85 — Change in unrealized losses included in other comprehensive income (loss) (35 ) — (35 ) — Purchases — 1,250 1,250 (737 ) Issues — 5,441 5,441 (9,058 ) Sales (237 ) — (237 ) — Settlements — — — 61 Transfers into Level 3 128,880 — 128,880 — Transfers out of Level 3 — — — — Level 3, end of period $ 133,376 $ 20,177 $ 153,553 $ (19,725 ) 4. 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 nine months ended September 30, 2016 and 2015 : Nine Months Ended September 30, 2016 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of period $ 112,453 $ 41,503 $ 153,956 $ (42,029 ) Total realized and unrealized gains included in earnings 3,901 — 3,901 — Total realized and unrealized losses included in earnings (2,464 ) — (2,464 ) — Total income included in other underwriting (loss) income — 5,199 5,199 18,305 Total loss included in other underwriting (loss) income — (11,544 ) (11,544 ) (8,541 ) Change in unrealized gains included in other comprehensive income (loss) 384 — 384 — Change in unrealized losses included in other comprehensive income (loss) (121 ) — (121 ) — Purchases 16,678 — 16,678 — Issues — 22,964 22,964 (32,780 ) Sales (24,100 ) — (24,100 ) — Settlements — (25,553 ) (25,553 ) 37,104 Transfers into Level 3 79,332 — 79,332 — Transfers out of Level 3 (5,516 ) — (5,516 ) — Level 3, end of period $ 180,547 $ 32,569 $ 213,116 $ (27,941 ) Nine Months Ended September 30, 2015 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of period $ 12,290 $ 25,615 $ 37,905 $ (35,366 ) Total realized and unrealized gains included in earnings 113 — 113 — Total realized and unrealized losses included in earnings (35 ) — (35 ) — Total income included in other underwriting (loss) income — 7,184 7,184 35,610 Total loss included in other underwriting (loss) income — (24,788 ) (24,788 ) (9,772 ) Change in unrealized gains included in other comprehensive income (loss) 109 — 109 — Change in unrealized losses included in other comprehensive income (loss) (228 ) — (228 ) — Purchases — 1,250 1,250 (737 ) Issues — 17,774 17,774 (27,806 ) Sales (547 ) — (547 ) — Settlements — (6,858 ) (6,858 ) 18,346 Transfers into Level 3 130,850 — 130,850 — Transfers out of Level 3 (9,176 ) — (9,176 ) — Level 3, end of period $ 133,376 $ 20,177 $ 153,553 $ (19,725 )

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Share	5. 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 and participation rights in undistributed earnings. Net income available to Endurance Holdings 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. The following table sets forth the computation of basic and diluted earnings per common share for the three and nine months ended September 30, 2016 and 2015 : Three Months Ended Nine Months Ended 2016 2015 2016 2015 Numerator: Net income available to common and participating common shareholders $ 130,070 $ 43,635 $ 313,069 $ 219,944 Less amount allocated to participating common shareholders (1) (2,607 ) (1,251 ) (6,662 ) (6,442 ) Net income allocated to common shareholders $ 127,463 $ 42,384 $ 306,407 $ 213,502 Denominator: Weighted average shares - basic 66,185,375 57,923,044 65,920,276 48,453,368 Share equivalents: Options 37,597 111,760 53,438 137,366 Restricted shares 18,976 11,344 8,699 1,367 Weighted average shares - diluted 66,241,948 58,046,148 65,982,413 48,592,101 Basic earnings per common share $ 1.93 $ 0.73 $ 4.65 $ 4.41 Diluted earnings per common share $ 1.92 $ 0.73 $ 4.64 $ 4.39 (1) Represents earnings attributable to holders of unvested restricted shares and restricted share units issued under the Company's equity compensation plan that are considered participating. In periods of loss, no losses are allocated to participating common shareholders (unvested restricted shares and restricted share units). 5. Earnings per share, cont'd. Endurance Holdings declared a dividend of $396.8750 per Series C preferred share on August 17, 2016 ( 2015 - Series A: $0.484375 , Series B: $0.468750 , Series C - Nil ). The Series C preferred share dividend was paid on September 15, 2016 to shareholders of record on September 1, 2016 . Endurance Holdings also declared a dividend of $0.38 per common share on August 17, 2016 ( 2015 - $0.35 ). The dividend was paid on September 30, 2016 to shareholders of record on September 16, 2016 . On June 1, 2016, Endurance Holdings redeemed all 9,200,000 of its Series B preferred shares. The Series B preferred shares were redeemed at a redemption price of $25.00 per share together with a dividend of $0.395830 per share. Three Months Ended Nine Months Ended 2016 2015 2016 2015 Dividends declared per Series A preferred share $ — $ 0.484375 $ — $ 1.453125 Dividends declared per Series B preferred share $ — $ 0.468750 $ 0.864580 $ 1.406250 Dividends declared per Series C preferred share $ 396.8750 $ — $ 1,283.2292 $ — Dividends declared per common share $ 0.38 $ 0.35 $ 1.14 $ 1.05

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	6. Accumulated other comprehensive income (loss) The following tables present the changes in accumulated other comprehensive income (loss) balances by component for the three months ended September 30, 2016 and 2015 : For the Three Months Ended September 30, 2016 Losses on cash flow hedges Unrealized gains (losses) on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,634 ) $ 103,957 $ (82,374 ) $ 19,949 Other comprehensive income (loss) before reclassifications — 24,799 (13,114 ) 11,685 Amounts reclassified from accumulated other comprehensive income (loss) (1) 22 (3,663 ) — (3,641 ) Net current period other comprehensive income (loss) 22 21,136 (13,114 ) 8,044 Ending balance $ (1,612 ) $ 125,093 $ (95,488 ) $ 27,993 (1) All amounts are net of tax. For the Three Months Ended September 30, 2015 Losses on cash flow hedges Unrealized gains (losses) on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,722 ) 43,610 $ (4,923 ) $ 36,965 Other comprehensive income (loss) before reclassifications — (18,258 ) (15,625 ) (33,883 ) Amounts reclassified from accumulated other comprehensive income (loss) (1) 22 (11,648 ) — (11,626 ) Net current period other comprehensive income (loss) 22 (29,906 ) (15,625 ) (45,509 ) Ending balance $ (1,700 ) $ 13,704 $ (20,548 ) $ (8,544 ) (1) All amounts are net of tax. 6. Accumulated other comprehensive income (loss), cont'd. The following tables present the changes in accumulated other comprehensive income (loss) balances by component for the nine months ended September 30, 2016 and 2015 : For the Nine Months Ended September 30, 2016 Losses on cash flow hedges Unrealized gains (losses) on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,678 ) $ (12,638 ) $ (32,318 ) $ (46,634 ) Other comprehensive income (loss) before reclassifications — 116,722 (63,170 ) 53,552 Amounts reclassified from accumulated other comprehensive income (loss) (1) 66 21,009 — 21,075 Net current period other comprehensive income (loss) 66 137,731 (63,170 ) 74,627 Ending balance $ (1,612 ) $ 125,093 $ (95,488 ) $ 27,993 (1) All amounts are net of tax. For the Nine Months Ended September 30, 2015 Losses on cash flow hedges Unrealized gains (losses) on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,766 ) $ 86,100 $ (7,628 ) $ 76,706 Other comprehensive income (loss) before reclassifications — (35,195 ) (12,920 ) (48,115 ) Amounts reclassified from accumulated other comprehensive income (loss) (1) 66 (37,201 ) — (37,135 ) Net current period other comprehensive income (loss) 66 (72,396 ) (12,920 ) (85,250 ) Ending balance $ (1,700 ) $ 13,704 $ (20,548 ) $ (8,544 ) (1) All amounts are net of tax. 6. Accumulated other comprehensive income (loss), cont'd. The following tables present the significant items reclassified out of accumulated other comprehensive income (loss) during the three months ended September 30, 2016 and 2015 : Three Months Ended September 30, 2016 Details about accumulated other comprehensive income (loss) components Amount reclassified from accumulated other comprehensive income (loss) Affected line item in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 22 Interest expense 22 Total before income taxes — Income tax expense $ 22 Total net of income taxes Unrealized gains on available for sale securities $ (4,476 ) Net realized and unrealized gains 183 Net impairment losses recognized in earnings (4,293 ) Total before income taxes 630 Income tax expense $ (3,663 ) Total net of income taxes Three Months Ended September 30, 2015 Details about accumulated other comprehensive Amount reclassified Affected line item in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 22 Interest expense 22 Total before income taxes — Income tax expense $ 22 Total net of income taxes Unrealized gains on available for sale securities $ (11,871 ) Net realized and unrealized gains 38 Net impairment losses recognized in earnings (11,833 ) Total before income taxes 185 Income tax expense $ (11,648 ) Total net of income taxes 6. Accumulated other comprehensive income (loss), cont'd. The following tables present the significant items reclassified out of accumulated other comprehensive income (loss) during the nine months ended September 30, 2016 and 2015 : Nine Months Ended September 30, 2016 Details about accumulated other comprehensive income (loss) components Amount reclassified from accumulated other comprehensive income (loss) Affected line item in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 66 Interest expense 66 Total before income taxes — Income tax expense $ 66 Total net of income taxes Unrealized losses on available for sale securities $ 9,620 Net realized and unrealized losses 10,647 Net impairment losses recognized in earnings 20,267 Total before income taxes 742 Income tax expense $ 21,009 Total net of income taxes Nine Months Ended September 30, 2015 Details about accumulated other comprehensive Amount reclassified Affected line item in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 66 Interest expense 66 Total before income taxes — Income tax expense $ 66 Total net of income taxes Unrealized gains on available for sale securities $ (39,230 ) Net realized and unrealized gains 1,111 Net impairment losses recognized in earnings (38,119 ) Total before income taxes 918 Income tax expense $ (37,201 ) Total net of income taxes

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	7. Derivatives 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. The Company's derivative instruments are recorded in the Condensed Consolidated Balance Sheets at fair value, with changes in fair value and gains and losses recognized in net realized and unrealized gains, net foreign exchange (gains) losses and other underwriting (loss) income in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income. The Company's derivatives are not designated as hedges under current accounting guidance. 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 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 overall investment strategy. TBAs represent commitments to purchase or sell a future issuance of agency mortgage-backed securities. For the period between 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 five -year period beginning March 30, 2012 as if these securities bore interest at a fixed rate of 4.905% . Loss Development Cover – as part of the sale of Montpelier U.S. Insurance Company ("MUSIC") to Selective Insurance Group, Inc. ("Selective"), Montpelier Reinsurance Ltd. (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. 7. Derivatives, cont'd. The fair values and the related notional values of derivatives at September 30, 2016 and December 31, 2015 are shown below. September 30, 2016 December 31, 2015 Fair Value Notional Principal Amount Fair Value Notional Principal Amount Derivatives recorded in other assets Foreign exchange forward contracts $ 213 $ 32,895 $ 425 $ 38,818 Credit default swaps 117 3,241 36 4,225 ILWs 2,336 20,000 — — TBAs 121,707 115,900 26,924 25,700 Energy and weather contracts 34,900 96,859 41,507 70,388 Total recorded in other assets $ 159,273 $ 68,892 Derivatives recorded in other liabilities Foreign exchange forward contracts $ 118 $ 41,736 $ 372 $ 30,400 Credit default swaps 31 2,059 276 7,800 Interest rate swaps 110 1,100 7 42,000 Interest rate futures — — 8 54,488 ILWs 733 14,209 259 19,500 LIBOR swap 114 100,000 233 100,000 TBAs 61,991 59,000 — — Loss development cover 3,978 24,426 2,904 22,322 Energy and weather contracts 30,883 153,344 42,029 148,325 Total recorded in other liabilities $ 97,958 $ 46,088 Net derivative asset $ 61,315 $ 22,804 At September 30, 2016 , the Company's derivative assets of $159.3 million ( December 31, 2015 - $68.9 million ) and liabilities of $98.0 million ( December 31, 2015 - $46.1 million ) are 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 September 30, 2016 and December 31, 2015 , the Company's derivative instruments were recorded on a gross basis in the Condensed Consolidated Balance Sheets. At September 30, 2016 , the Company held no reverse repurchase agreements. At December 31, 2015 , the Company held $30.0 million reverse repurchase agreements. These agreements were fully collateralized, were generally outstanding for a short period of time and were presented as part of cash and cash equivalents in the Condensed Consolidated Balance Sheets. The required collateral for these agreements was either cash or U.S. treasury securities at a minimum rate of 102% of the principal amount. Upon maturity, the Company received the principal and interest income. 7. Derivatives, cont'd. The gains and losses on the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income for derivatives for the three and nine months ended September 30, 2016 and 2015 were as follows: Three Months Ended Nine Months Ended 2016 2015 2016 2015 Total (losses) gains included in net foreign exchange (gains) losses from foreign exchange forward contracts $ (231 ) $ 155 $ (732 ) $ 1,281 Interest rate futures — (78 ) (227 ) 17 Credit default swaps 70 (143 ) (12 ) (134 ) Interest rate swaps (69 ) (705 ) (117 ) (940 ) Interest rate swaptions — 28 (27 ) 56 ILWs (958 ) (652 ) (898 ) (652 ) LIBOR swap 232 (173 ) 120 (173 ) TBAs 270 (82 ) 1,232 531 Total (losses) gains included in net realized and unrealized gains (455 ) (1,805 ) 71 (1,295 ) Energy and weather contracts 1,486 1,988 2,808 8,030 Loss development cover (618 ) (465 ) (2,104 ) (465 ) Total gains included in other underwriting (loss) income 868 1,523 704 7,565 Total gains (losses) from derivatives $ 182 $ (127 ) $ 43 $ 7,551

Stock-Based Employee Compensati

Stock-Based Employee Compensation And Other Stock Plans	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Employee Compensation And Other Stock Plans	8. Stock-based employee compensation and other stock plans The Company has a stock-based employee compensation plan, which provides the Company with the ability to grant options to purchase the Company's ordinary shares, share appreciation rights, restricted shares, restricted share units, share bonuses and other equity incentive awards to key employees. No options were granted, expired or vested during the quarters ended September 30, 2016 and 2015 . No options were exercised during the quarter ended September 30, 2016 ( 2015 - 480,000 ). The total intrinsic value of options exercised during the quarter ended September 30, 2015 was $9.5 million . The Company received proceeds of $23.1 million from the exercise of options during the quarter ended September 30, 2015 . The Company issued new ordinary shares in connection with the exercise of the above options. For the quarter ended September 30, 2016 , compensation costs recognized in earnings for all options totaled $0.1 million ( 2015 - $0.3 million ). At September 30, 2016 , compensation costs not yet recognized related to unvested stock options was $0.3 million ( 2015 - $1.3 million ). No options were granted or expired during the nine months ended September 30, 2016 and 2015 . During the nine months ended September 30, 2016 , 160,000 ( 2015 - 480,000 ) options were exercised. During the nine months ended September 30, 2016 , 160,000 options vested ( 2015 - 160,000 ). The total intrinsic value of options exercised during the nine months ended September 30, 2016 was $3.2 million ( 2015 - $9.5 million ). The Company received proceeds of $7.7 million from the exercise of options during the nine months ended September 30, 2016 ( 2015 - $23.1 million ). The Company issued new ordinary shares in connection with the exercise of the above options. For the nine months ended September 30, 2016 , compensation costs recognized in earnings for all options totaled $0.7 million ( 2015 - $1.3 million ). During the quarter ended September 30, 2016 , the Company granted an aggregate of 24,250 ( 2015 – 856,629 ) restricted shares and restricted share units. The restricted shares and restricted share units granted had weighted average grant date fair values of $1.6 million ( 2015 - $59.4 million ). During the quarter ended September 30, 2016 , the aggregate fair value of restricted shares and restricted share units that vested was nil ( 2015 - $23.0 million ). For the quarter ended September 30, 2016 , compensation costs recognized in earnings for all restricted shares and restricted share units were $8.2 million ( 2015 - $28.1 million ). At September 30, 2016 , compensation costs not yet recognized related to unvested restricted shares and restricted share units was $34.4 million ( 2015 - $32.0 million ). During the nine months ended September 30, 2016 , the Company granted an aggregate of 638,217 ( 2015 – 1,360,981 ) restricted shares and restricted share units. The restricted shares and restricted share units granted had weighted average grant date fair values of $38.5 million ( 2015 - $89.4 million ). During the nine months ended September 30, 2016 , the aggregate fair value of restricted shares and restricted share units that vested was $41.2 million ( 2015 - $44.7 million ). For the nine months ended September 30, 2016 , compensation costs recognized in earnings for all restricted shares and restricted share units were $27.4 million ( 2015 - $45.0 million ). Employee Share Purchase Plan The Company also has an Employee Share Purchase Plan ("ESPP") under which employees of Endurance Holdings and certain of its subsidiaries may purchase the Company's ordinary shares. For the three and nine months ended September 30, 2016 , total expenses related to the Company's ESPP were approximately $109,000 ( 2015 - $76,000 ) and $324,000 ( 2015 - $220,000 ), respectively.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment Reporting	9. 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, which are comprised of the following lines of business: Insurance segment lines of business • Agriculture • Casualty and other specialty • Professional lines • Property, marine/energy and aviation Reinsurance segment lines of business • Catastrophe • Property • Casualty • Professional lines • Specialty 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 the 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. 9. Segment reporting, cont'd. The following table provides a summary of segment revenues and results for the three months ended September 30, 2016 and the reserve for losses and loss expenses as of September 30, 2016 : Three Months Ended September 30, 2016 Insurance Reinsurance Total Revenues Gross premiums written $ 568,277 $ 192,410 $ 760,687 Ceded premiums written (365,573 ) (46,128 ) (411,701 ) Net premiums written 202,704 146,282 348,986 Net premiums earned 272,603 337,553 610,156 Other underwriting loss — (466 ) (466 ) 272,603 337,087 609,690 Expenses Net losses and loss expenses 202,717 128,745 331,462 Acquisition expenses 41,773 79,618 121,391 General and administrative expenses 40,658 27,080 67,738 285,148 235,443 520,591 Underwriting (loss) income $ (12,545 ) $ 101,644 89,099 Net investment income 62,236 Corporate expenses (11,952 ) Net foreign exchange gains 18,576 Net realized and unrealized gains 13,405 Net impairment losses recognized in earnings (183 ) Amortization of intangibles (21,154 ) Interest expense (10,826 ) Income before income taxes $ 139,201 Net loss ratio 74.4 % 38.1 % 54.3 % Acquisition expense ratio 15.3 % 23.6 % 19.9 % General and administrative expense ratio 14.9 % 8.0 % 13.1 % (1) Combined ratio 104.6 % 69.7 % 87.3 % Reserve for losses and loss expenses $ 2,712,403 $ 2,095,465 $ 4,807,868 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. 9. Segment reporting, cont'd. The following table provides a summary of segment revenues and results for the three months ended September 30, 2015 and the reserve for losses and loss expenses as of September 30, 2015 : Three Months Ended September 30, 2015 Insurance Reinsurance Total Revenues Gross premiums written $ 448,563 $ 194,034 $ 642,597 Ceded premiums written (273,626 ) (32,281 ) (305,907 ) Net premiums written 174,937 161,753 336,690 Net premiums earned 234,143 322,860 557,003 Other underwriting income — 227 227 234,143 323,087 557,230 Expenses Net losses and loss expenses 139,603 124,390 263,993 Acquisition expenses 24,375 66,082 90,457 General and administrative expenses 31,880 28,913 60,793 195,858 219,385 415,243 Underwriting income $ 38,285 $ 103,702 141,987 Net investment income 16,533 Corporate expenses (74,308 ) Net foreign exchange losses (8,621 ) Net realized and unrealized gains 5,029 Net impairment losses recognized in earnings (38 ) Amortization of intangibles (11,318 ) Interest expense (12,324 ) Income before income taxes $ 56,940 Net loss ratio 59.6 % 38.5 % 47.4 % Acquisition expense ratio 10.4 % 20.5 % 16.2 % General and administrative expense ratio 13.6 % 9.0 % 24.3 % (1) Combined ratio 83.6 % 68.0 % 87.9 % Reserve for losses and loss expenses $ 2,429,385 $ 2,060,451 $ 4,489,836 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. 9. Segment reporting, cont'd. The following table provides gross and net premiums written by line of business for the three months ended September 30, 2016 and 2015 : Gross premiums written Net premiums written Gross premiums written Net premiums written Business Segment 2016 2016 2015 2015 Insurance Agriculture $ 151,483 $ 49,062 $ 156,145 $ 29,634 Casualty and other specialty 168,644 68,211 128,509 64,490 Professional lines 97,432 30,328 80,069 37,479 Property, marine/energy and aviation 150,718 55,103 83,840 43,334 Total Insurance 568,277 202,704 448,563 174,937 Reinsurance Catastrophe 51,040 32,696 40,660 14,814 Property 41,975 40,882 53,423 52,887 Casualty 35,438 35,772 42,802 42,802 Professional lines 33,289 31,883 31,705 31,705 Specialty 30,668 5,049 25,444 19,545 Total Reinsurance 192,410 146,282 194,034 161,753 Total $ 760,687 $ 348,986 $ 642,597 $ 336,690 9. Segment reporting, cont'd. The following table provides a summary of the segment revenues and results for the nine months ended September 30, 2016 : Nine Months Ended September 30, 2016 Insurance Reinsurance Total Revenues Gross premiums written $ 1,997,100 $ 1,512,194 $ 3,509,294 Ceded premiums written (1,183,850 ) (319,848 ) (1,503,698 ) Net premiums written 813,250 1,192,346 2,005,596 Net premiums earned 745,956 1,016,999 1,762,955 Other underwriting loss — (1,980 ) (1,980 ) 745,956 1,015,019 1,760,975 Expenses Net losses and loss expenses 499,104 451,798 950,902 Acquisition expenses 104,999 232,195 337,194 General and administrative expenses 108,912 86,130 195,042 713,015 770,123 1,483,138 Underwriting income $ 32,941 $ 244,896 277,837 Net investment income 117,394 Corporate expenses (35,553 ) Net foreign exchange gains 63,056 Net realized and unrealized gains 33,539 Net impairment losses recognized in earnings (10,647 ) Amortization of intangibles (63,471 ) Interest expense (33,053 ) Income before income taxes $ 349,102 Net loss ratio 66.9 % 44.4 % 53.9 % Acquisition expense ratio 14.1 % 22.8 % 19.1 % General and administrative expense ratio 14.6 % 8.5 % 13.1 % (1) Combined ratio 95.6 % 75.7 % 86.1 % (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. 9. Segment reporting, cont'd. The following table provides a summary of the segment revenues and results for the nine months ended September 30, 2015 : Nine Months Ended September 30, 2015 Insurance Reinsurance Total Revenues Gross premiums written $ 1,653,647 $ 1,151,566 $ 2,805,213 Ceded premiums written (984,372 ) (160,114 ) (1,144,486 ) Net premiums written 669,275 991,452 1,660,727 Net premiums earned 571,467 833,530 1,404,997 Other underwriting income — 4,022 4,022 571,467 837,552 1,409,019 Expenses Net losses and loss expenses 359,598 315,453 675,051 Acquisition expenses 57,960 199,561 257,521 General and administrative expenses 89,289 81,359 170,648 506,847 596,373 1,103,220 Underwriting income $ 64,620 $ 241,179 305,799 Net investment income 90,646 Corporate expenses (99,210 ) Net foreign exchange losses (29,154 ) Net realized and unrealized gains 32,898 Net impairment losses recognized in earnings (1,111 ) Amortization of intangibles (14,496 ) Interest expense (30,445 ) Income before income taxes $ 254,927 Net loss ratio 63.0 % 37.8 % 48.1 % Acquisition expense ratio 10.1 % 23.9 % 18.3 % General and administrative expense ratio 15.6 % 9.8 % 19.2 % (1) Combined ratio 88.7 % 71.5 % 85.6 % (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. 9. Segment reporting, cont'd. The following table provides gross and net premiums written by line of business for the nine months ended September 30, 2016 and 2015 : Gross premiums written Net premiums written Gross premiums written Net premiums written Business Segment 2016 2016 2015 2015 Insurance Agriculture $ 714,621 $ 254,727 $ 785,073 $ 254,771 Casualty and other specialty 484,980 209,673 375,247 174,850 Professional lines 297,526 124,866 231,565 105,153 Property, marine/energy and aviation 499,973 223,984 261,762 134,501 Total Insurance 1,997,100 813,250 1,653,647 669,275 Reinsurance Catastrophe 488,865 319,245 304,900 190,579 Property 229,087 222,242 209,683 206,454 Casualty 216,421 215,412 149,032 149,032 Professional lines 217,476 215,134 209,803 209,803 Specialty 360,345 220,313 278,148 235,584 Total Reinsurance 1,512,194 1,192,346 1,151,566 991,452 Total $ 3,509,294 $ 2,005,596 $ 2,805,213 $ 1,660,727

Commitments And Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	10. Commitments and contingencies Concentrations of credit risk. The Company's reinsurance recoverables on paid and unpaid losses at September 30, 2016 and December 31, 2015 amounted to $1,436.3 million and $1,196.0 million , respectively. At September 30, 2016 , substantially all reinsurance recoverables on paid and unpaid losses were due from the U.S. government or from reinsurers rated A- or better by A.M. Best Company, Inc. or Standard & Poor's Corporation. At September 30, 2016 and December 31, 2015 , the Company held collateral of $479.8 million and $321.5 million , respectively, related to its ceded reinsurance agreements. Major production sources. The following table shows the percentage of gross premiums written generated through the Company's largest brokers for the nine months ended September 30, 2016 and 2015 , respectively: Broker 2016 2015 Marsh & McLennan Companies, Inc. 20.6 % 24.9 % Aon Benfield 14.4 % 15.8 % Willis Companies 9.5 % 12.8 % Total of largest brokers 44.5 % 53.5 % Letters of credit. As of September 30, 2016 , the Company had issued letters of credit of $278.7 million ( December 31, 2015 – $341.6 million ) under its credit facilities and letter of credit reimbursement agreements in favor of certain ceding companies to collateralize obligations. Investment commitments. As of September 30, 2016 and December 31, 2015 , the Company had pledged cash and cash equivalents and fixed maturity investments of $111.2 million and $108.9 million , respectively, in favor of certain ceding companies to collateralize obligations. As of September 30, 2016 and December 31, 2015 , the Company had also pledged $319.3 million and $383.3 million of its cash and fixed maturity investments as required to meet collateral obligations for $278.7 million and $341.6 million , respectively, in letters of credit outstanding under its credit facilities and letter of credit reimbursement agreements. In addition, as of September 30, 2016 and December 31, 2015 , cash and fixed maturity investments with fair values of $211.1 million and $208.3 million were on deposit with U.S. state regulators, respectively. 10. Commitments and contingencies, cont'd. The Company is subject to certain commitments with respect to other investments at September 30, 2016 and December 31, 2015 . See Note 3, 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 collateralize 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 September 30, 2016 , the fair value of the assets held in the Blue Water Trusts was $405.2 million ( December 31, 2015 - $438.9 million ), which met the minimum value required on that date. As of September 30, 2016 , Blue Capital Re had pledged $180.7 million ( December 31, 2015 - $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 September 30, 2016 , the fair value of the assets held in the Blue Capital Re ILS Trusts was $3.3 million ( December 31, 2015 - $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 September 30, 2016 , the fair value of the investments held in the Endurance Reinsurance Trust exceeded $806.6 million ( December 31, 2015 - $94.1 million ), the minimum value required on that date. During 2015, Endurance Bermuda also established a second multi-beneficiary reinsurance trust domiciled in Delaware 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 (the "Reduced Collateral Trust"). As of September 30, 2016 , the fair value of the assets held in the Reduced Collateral Trust exceeded $21.4 million ( December 31, 2015 - $10.8 million ), the minimum value required on that date. 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. As of September 30, 2016 , the fair value of the assets held in the MUSIC Trust was $22.1 million ( December 31, 2015 - $21.3 million ). Endurance Bermuda 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 subject to approval by Lloyd's and is based on ECCL's Solvency Capital Requirement, which is used to determine the required amount of FAL. As of September 30, 2016 , the fair value of cash and investments held in the Lloyd's Capital Trust was $278.6 million ( December 31, 2015 - $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 September 30, 2016 , the fair value of all assets held in the Premiums Trust Funds was $177.2 million ( December 31, 2015 - $231.9 million ). 10. Commitments and contingencies, cont'd. The Company's investment assets held in trust appear on the Company's Condensed 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 gross written premiums ( 0.35% with respect to 2016). 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 3.0% of their underwriting capacity each year should it decide that such additional contributions are necessary. The Company currently estimates that its 2016 obligation to the Lloyd's New Central Fund will be approximately $1.2 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 ( 0.45% of gross written premiums with respect to 2016) 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 2016 obligation to Lloyd's for such charges will be approximately $1.6 million and accrues for this obligation ratably throughout the year on a quarterly basis. 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 permitted BCRH to borrow up to $20.0 million on a revolving basis for working capital and general corporate purposes. The Company was entitled to receive an annual guarantee fee from BCRH equal to 0.125% of the facility's total capacity (the "BCRH Guarantee Agreement"). The BCRH Credit Agreement and the BCRH Guarantee Agreement expired on April 29, 2016. As of September 30, 2016 , BCRH had no outstanding borrowings under the BCRH Credit Agreement ( December 31, 2015 - $13.0 million ). 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 on February 22, 2016 and was subject to an annual interest rate of 1.48% , and $4.0 million was repaid on March 11, 2016 and was subject to an annual interest rate of 1.51% . On May 6, 2016, the Company, through a wholly-owned subsidiary, entered into a credit facility agreement with BCRH (the "BCRH Credit Facility"). The BCRH Credit Facility provides BCRH with an unsecured $20.0 million revolving credit facility for working capital and general corporate purposes and expires on September 30, 2018. Borrowings under the BCRH Credit Facility bear interest, set at the time of the borrowing, at a rate equal to the applicable LIBOR rate plus 150 basis points. The BCRH Credit Facility contains covenants that limit BCRH's ability, among other things, to grant liens on its assets, sell assets, merge or consolidate, or incur debt. If BCRH fails to comply with any of these covenants, the Company could terminate the BCRH Credit Facility and exercise remedies against BCRH. In addition, in the event of a default in the performance of any of the agreements or covenants under certain management agreements with BCML by BCRH, the Company has the right to terminate the BCRH Credit Facility. As of September 30, 2016 , BCRH had no outstanding borrowings under the BCRH Credit Facility. 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 permitted BCGR to borrow up to $20.0 million on a revolving basis for working capital and general corporate purposes. The Company was entitled to receive an annual guarantee fee from BCGR equal to 0.125% of the facility's total capacity (the "BCGR Guarantee Agreement"). The BCGR Credit Agreement and the BCGR Guarantee Agreement expired on May 12, 2016. As of September 30, 2016 , BCGR had no outstanding borrowings under the BCGR Credit Agreement ( December 31, 2015 - $6.0 million ). With respect to BCGR's outstanding borrowing 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 on February 12, 2016 and was subject to an annual interest rate of 1.51% . 10. Commitments and contingencies, cont'd. On May 6, 2016, the Company, through a wholly-owned subsidiary, entered into a credit facility agreement with BCGR (the "BCGR Credit Facility"). The BCGR Credit Facility provides BCGR with an unsecured $20.0 million revolving credit facility for working capital and general corporate purposes and expires on September 30, 2018. Borrowings under the BCGR Credit Facility bear interest, set at the time of the borrowing, at a rate equal to the applicable LIBOR rate plus 150 basis points. The BCGR Credit Facility contains covenants that limit BCGR's ability, among other things, to grant liens on its assets, sell assets, merge or consolidate, or incur debt. If BCGR fails to comply with any of these covenants, the Company could terminate the BCGR Credit Facility and exercise remedies against BCGR. In addition, in the event of a default in the performance of any of the agreements or covenants under certain management agreements with BCML by BCGR, the Company has the right to terminate the BCGR Credit Facility. As of September 30, 2016 , BCGR had no outstanding borrowings under the BCGR Credit Facility. Investment repurchase agreements . At September 30, 2016 , the Company's investment repurchase agreement obligations of $121.0 million were fully collateralized. The following table presents the fair value of collateral pledged under repurchase agreements by investment category. The remaining contractual maturity of the repurchase agreements is less than 30 days. September 30, 2016 Collateral pledged under repurchase agreements U.S. government and agencies securities $ 25,876 Residential mortgage-backed securities 98,427 $ 124,303 Gross amount of recognized liabilities for repurchase agreements $ 120,997 Pledged collateral levels are monitored daily and are generally maintained at an agreed-upon percentage of the fair value of the amounts borrowed during the life of the transaction. In the event of a decline in the fair value of the pledged collateral under these agreements, the Company may be required to transfer cash or additional securities as pledged collateral under these agreements. Upon termination of the transactions, the Company and its counterparties are obligated to return the amounts borrowed and the securities transferred, respectively. Reinsurance commitments . In the ordinary course of business, the Company periodically enters into reinsurance agreements that include terms that 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. Operating leases. The Company leases office space and office equipment under operating leases. Future minimum lease commitments at September 30, 2016 are as follows: Twelve months ended September 30, Amount 2017 $ 15,810 2018 16,194 2019 15,644 2020 14,874 2021 13,132 2022 and thereafter 17,425 $ 93,079 Total net lease expense under operating leases for the nine months ended September 30, 2016 was $8.7 million ( 2015 – $10.5 million ). 10. Commitments and contingencies, cont'd. 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 or business. Pursuant to the Company's insurance and reinsurance agreements, disputes are generally required to be settled by arbitration.

Debt And Financing Arrangements

Debt And Financing Arrangements	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	11. Debt and financing arrangements Credit Facility On March 23, 2016, the Company and certain designated subsidiaries of the Company entered into a $450.0 million five -year letter of 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 $700.0 million credit agreement, dated April 19, 2012, with JPMorgan as administrative agent. As of September 30, 2016 , there were letters of credit outstanding under the Credit Facility of $255.3 million ( December 31, 2015 – $329.9 million ). The Credit Facility does not provide for revolving or term loans. The Credit Facility is collateralized on a several basis by each entity incurring such obligation by cash and securities deposited into collateral accounts from time to time with Deutsche Bank Trust Company Americas as collateral agent. So long as there is no default under the terms of the Credit Facility, the Company may request that the size of the Credit Facility be increased by $100.0 million , but no participating lender is obligated to increase its commitments under the Credit Facility. The Company is required to pay a fee of 0.40% per annum on the daily stated amount of outstanding letters of credit issued under the Credit Facility. In addition, the Credit Facility requires the Company to pay to the lenders a commitment fee in the amount of 0.125% per annum on the average daily amount of the unused commitments of the lenders. The Credit Facility permits a lender, if requested and in its discretion, to issue a letter of credit pursuant to which it fronts for the other lenders. For such letters of credit, such fronting lenders may receive certain fronting fees from the Company. The Credit Facility requires the Company's compliance with certain customary restrictive covenants, including a financial covenant that the Company maintain a leverage ratio of no greater than 0.35 :1.00 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 Credit Facility also contains customary event of default provisions, including failure to pay any unpaid drawing under a letter of credit under the Credit Facility or interest thereon and failure to pay any fee under the Credit Facility, insolvency events of the Company or any of its subsidiaries (other than certain immaterial subsidiaries), a change in control of the Company, a breach of the representations or covenants in the Credit Facility or the security documents relating thereto and certain defaults by the Company or its subsidiaries under other indebtedness. In the case of an event of default that occurs as a result of an insolvency event of the Company or one of its designated subsidiary borrowers, the commitments of the lenders will automatically terminate and the repayment of outstanding obligations will be automatically accelerated. Upon the occurrence of any other event of default under the Credit Facility, the lenders can terminate their commitments under the Credit Facility, require repayment of any outstanding obligations under the Credit Facility, give notice of non-extension 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 collateral held by the lenders (or any agent on their behalf) under the Credit Facility.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2016
Subsequent Events [Abstract]
Subsequent Events [Text Block]	12. Subsequent events Merger with Sompo Holdings, Inc. On October 5, 2016, the Company entered into an agreement and plan of merger (the "Merger Agreement") for the acquisition of 100% of the outstanding ordinary shares of the Company by Sompo Holdings, Inc. ("SOMPO") for $93.00 per share in cash (the "Merger"). The Merger has been approved by both companies' Board of Directors. The Merger is expected to close as soon as practicable following the satisfaction of customary closing conditions including, but not limited to, approval by the Company's shareholders and regulatory approvals. There can be no assurance that the Merger will occur. 12. Subsequent events, cont'd. Under the terms of the Merger Agreement, the aggregate consideration for the Merger will be approximately $6,304.0 million in cash. The purchase will be financed by SOMPO with existing sources of liquidity and supplementary facilities without a financing contingency. If the Merger is terminated under certain circumstances, the Company is obligated to pay SOMPO a cash termination fee of $204.9 million together with SOMPO's expenses relating to the Merger up to $15.8 million . The Company incurred $1.0 million of corporate expenses associated with the Merger during the three months ended September 30, 2016 and is contractually obligated to pay investment banking fees upon closing of the Merger. The Company expects to incur additional costs and expenses associated with the Merger during the fourth quarter of 2016 and the first quarter of 2017. Hurricane Matthew On October 7 and 8, 2016, Hurricane Matthew affected the southeastern coast of the United States, ultimately making landfall in South Carolina. To date, reported claims as a result of this storm have been limited. While losses emanating from the storm cannot be accurately estimated at this time, the Company may need to establish appropriate loss reserves related to Hurricane Matthew in the fourth quarter of 2016, which may have a negative impact on its results of operations.

Summary Of Significant Accoun20

Summary Of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Repurchase Agreements Policy	(a) Investments The Company has entered into investment repurchase agreements, whereby the Company sells securities and repurchases them at a future date for a predetermined price. These investment repurchase agreements are accounted for as secured borrowings and are recorded at the contractual repurchase price plus accrued interest. The securities to be repurchased are the same, or substantially the same, as those sold. The fair value of the underlying securities is included in securities pledged under repurchase agreements in the Consolidated Balance Sheets. The use of the cash received by the Company from the counterparty pursuant to the repurchase agreement is not restricted. 2. Summary of significant accounting policies, cont'd. (a) Investments, cont'd. The obligation to return the cash is included in payable under repurchase agreements in the Consolidated Balance Sheets. In these repurchase transactions, the securities sold by the Company (pledged collateral) may be sold or repledged by the counterparties with whom the repurchase agreement is executed.
New Accounting Pronouncements	(b) 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. This guidance is not expected to have a material impact on the Company's Unaudited Condensed 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 became effective for public business entities for annual and interim periods beginning after December 15, 2015. Early adoption was permitted. The Company adopted ASU 2015-02 effective January 1, 2016 and it did not have a material impact on the Company's Unaudited Condensed 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 became effective for public business entities in interim and annual periods beginning after December 15, 2015. Early adoption was permitted. The Company adopted ASU 2015-16 effective January 1, 2016 and it did not have a material impact on the Company's Unaudited Condensed Consolidated Financial Statements. In January 2016, the FASB issued ASU 2016-01, "Financial Instruments - Overall, Recognition and Measurement of Financial Assets and Financial Liabilities" ("ASU 2016-01"). ASU 2016-01 requires entities to measure certain equity investments at fair value and recognize any changes in fair value in net income unless the investments qualify for a practicability exception. For financial liabilities measured using the fair value option, entities will need to present any change in fair value caused by a change in instrument-specific credit risk separately in other comprehensive income. ASU 2016-01 also changes certain disclosure requirements and other aspects of current U.S. GAAP. ASU 2016-01 is effective for public business entities for annual and interim periods beginning after December 15, 2017. Early adoption is not permitted, except for certain provisions. ASU 2016-01 should be applied by means of a cumulative-effect adjustment to the balance sheet as of the beginning of the fiscal year of adoption. The amendments related to equity securities without readily determinable fair values (including disclosure requirements) should be applied prospectively. The Company is currently evaluating the impact of this guidance on its Unaudited Condensed Consolidated Financial Statements. 2. Summary of significant accounting policies, cont'd. (b) Recent accounting pronouncements, cont'd. In February 2016, the FASB issued ASU 2016-02, "Leases" ("ASU 2016-02"). The objective of ASU 2016-02 is to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. ASU 2016-02 is effective for public business entities for annual and interim periods beginning after December 15, 2018. Early adoption is permitted. ASU 2016-02 must be applied using a modified retrospective approach. The Company is currently evaluating the impact of this guidance on its Unaudited Condensed Consolidated Financial Statements. In March 2016, the FASB issued ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting" ("ASU 2016-09"). ASU 2016-09 will change how companies account for certain aspects of share-based payments to employees. Entities will be required to recognize the income tax effects of awards in the income statement when the awards vest or are settled. The guidance also changes employers' accounting for an employee's use of shares to satisfy the employer's statutory income tax withholding obligation, and accounting for forfeitures. ASU 2016-09 is effective for public business entities for annual and interim periods beginning after December 15, 2016. Early adoption is permitted. This guidance is not expected to have a material impact on the Company's Unaudited Condensed Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses - Measurement of Credit Losses on Financial Instruments" ("ASU 2016-13"). ASU 2016-13 will change how companies measure credit losses for most financial assets and certain other instruments that aren't measured at fair value through net income. The standard will replace today's "incurred loss" approach with an "expected loss" model for instruments measured at amortized cost and require entities to record allowances for available-for-sale debt securities rather than reduce the carrying amount, as they do today under the other-than-temporary impairment model. ASU 2016-13 is effective for public business entities for annual and interim periods beginning after December 15, 2019. Early adoption is permitted for all entities for annual periods beginning after December 15, 2018, and interim periods therein. The Company is currently evaluating the impact of this guidance on its Unaudited Condensed Consolidated Financial Statements.

Investments (Policy)

Investments (Policy)	9 Months Ended
	Sep. 30, 2016
Investments [Abstract]
Other Investments	In addition to the Company's fixed maturity, short-term and equity securities, the Company invests in alternative funds and specialty funds. The Company's alternative funds and specialty funds are recorded on the Company's Condensed Consolidated Balance Sheets as "other investments."
Gain Loss On Investments	Realized gains and losses are recognized in earnings using the first in, first out method.
Variable Interest Entities	Other Investments The Company is involved in the normal course of business with VIEs 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 reassesses its VIE determination with respect to an entity on an ongoing basis. The Company determined that it was not the primary beneficiary for any of these investments as of September 30, 2016 . 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 Condensed Consolidated Balance Sheets and any unfunded investment commitments. Collateralized Reinsurance Entities As of September 30, 2016 , Endurance Holdings and Endurance Bermuda together owned 33.3% of BCRH's common shares. BCRH is considered a VIE under U.S. GAAP due to service agreements for investment management, underwriting and insurance management and administrative services between BCRH and BCML, and the economic penalty to terminate the service agreements by BCRH. The Company has determined that it is BCRH's primary beneficiary due to its ability to direct the activities of BCRH through BCML along with its economic interest in BCRH. As a result, the Company fully consolidates the assets, liabilities and operations of BCRH and its subsidiaries within its Unaudited Condensed 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 Unaudited Condensed 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 September 30, 2016 , Endurance Bermuda owned 25.2% 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 Unaudited Condensed Consolidated Financial Statements. However, the BCGR Cell and Blue Water Re Ltd. ("Blue Water Re"), the Company's wholly-owned Bermuda-based special purpose insurance vehicle, are considered VIEs under U.S. GAAP due to service agreements for investment management, underwriting and insurance management and administrative services between Blue Water Re and BCML. The Company has determined that it is the primary beneficiary of these entities due to its ability to direct the activities of Blue Water Re and the BCGR Cell along with its economic interest in these entities. Therefore, as funds held in BCGR are invested in the BCGR Cell, and ultimately into Blue Water Re, they are included in the Company's Unaudited Condensed Consolidated Financial Statements. Conversely, as funds previously invested by BCGR and the BCGR Cell into Blue Water Re are returned to BCGR, they are no longer included in the Company's Unaudited Condensed Consolidated Financial Statements. The interests in the BCGR Cell and Blue Water Re that the Company fully consolidates that are attributable to third-party investors are reported within the Company's Unaudited Condensed 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)	9 Months Ended
	Sep. 30, 2016
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. The Company uses models that include unobservable inputs to price its corporate bank loan portfolio. As such, the fair values of the corporate bank loans are generally classified in Level 3. • 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 credits for like or similar securities. The Company generally classifies the fair values of its equity securities in Level 1 or 2. 4. Fair value measurement, cont'd. • Structured securities including agency and non-agency, residential and commercial mortgage-backed securities, 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. • Securities pledged under repurchase agreements - These securities have been sold under a repurchase agreement and consist of U.S. government and agencies and residential mortgage-backed securities. Please refer to the pricing methods used for these types of securities. • 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 and energy 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 7.0% Senior Notes due July 15, 2034, the 4.7% Senior Notes due October 15, 2022 (together, the "Senior Notes") and the Trust Preferred Securities. The fair values of the Senior Notes were obtained from a third party pricing service and pricing was based on the spread above the risk-free yield curve. The fair values of the Trust Preferred Securities were 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. 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, payable under repurchase agreements, the amount outstanding under the BCRH Credit Agreement (as defined in Note 10) and other financial instruments not described above approximated their fair values at September 30, 2016 and December 31, 2015 .
Fair Value Transfer Between Levels	Transfers between levels are assumed to occur at the end of each period.

Earnings Per Share (Policy)

Earnings Per Share (Policy)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
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 and participation rights in undistributed earnings. Net income available to Endurance Holdings 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.

Derivatives (Policy)

Derivatives (Policy)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Accounting policy for derivatives	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. The Company's derivative instruments are recorded in the Condensed Consolidated Balance Sheets at fair value, with changes in fair value and gains and losses recognized in net realized and unrealized gains, net foreign exchange (gains) losses and other underwriting (loss) income in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income. The Company's derivatives are not designated as hedges under current accounting guidance. 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 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 overall investment strategy. TBAs represent commitments to purchase or sell a future issuance of agency mortgage-backed securities. For the period between 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 five -year period beginning March 30, 2012 as if these securities bore interest at a fixed rate of 4.905% . Loss Development Cover – as part of the sale of Montpelier U.S. Insurance Company ("MUSIC") to Selective Insurance Group, Inc. ("Selective"), Montpelier Reinsurance Ltd. (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 September 30, 2016 and December 31, 2015 , the Company's derivative instruments were recorded on a gross basis in the Condensed Consolidated Balance Sheets.

Segment Reporting (Policy)

Segment Reporting (Policy)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
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, which are comprised of the following lines of business: Insurance segment lines of business • Agriculture • Casualty and other specialty • Professional lines • Property, marine/energy and aviation Reinsurance segment lines of business • Catastrophe • Property • Casualty • Professional lines • Specialty 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 the 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.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2016
Investments [Abstract]
Composition Of Net Investment Income	The components of net investment income for the three and nine months ended September 30, 2016 and 2015 are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Fixed income investments $ 41,078 $ 36,204 $ 118,382 $ 96,145 Equity investments 1,906 1,748 8,754 5,200 Other investments 22,804 (17,716 ) (201 ) (1,758 ) Cash and cash equivalents 392 515 2,043 2,108 $ 66,180 $ 20,751 $ 128,978 $ 101,695 Investment expenses (3,944 ) (4,218 ) (11,584 ) (11,049 ) Net investment income $ 62,236 $ 16,533 $ 117,394 $ 90,646
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 September 30, 2016 and December 31, 2015 . 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. September 30, 2016 December 31, 2015 Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 508,899 $ 509,417 $ 622,070 $ 622,248 Due after one year through five years 2,005,903 2,031,970 2,005,456 1,995,502 Due after five years through ten years 736,318 757,530 683,147 676,932 Due after ten years 45,303 48,537 33,168 34,651 Residential mortgage-backed securities 1,299,811 1,329,069 1,301,083 1,311,373 Commercial mortgage-backed securities 702,760 714,142 817,570 812,886 Collateralized loan and debt obligations 392,578 393,922 419,795 405,128 Asset-backed securities 464,826 466,873 510,540 507,255 Total $ 6,156,398 $ 6,251,460 $ 6,392,829 $ 6,365,975
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 September 30, 2016 and December 31, 2015 : September 30, 2016 December 31, 2015 Fixed maturity investments U.S. government and agencies securities $ 396,468 $ 319,674 U.S. state and municipal securities 5,203 5,559 Foreign government securities 128,786 49,861 Government guaranteed corporate securities 31,526 38,201 Corporate securities 951,523 532,192 Residential mortgage-backed securities 391,704 258,574 Commercial mortgage-backed securities 181,569 127,124 Collateralized loan and debt obligations (1) 93,307 103,219 Asset-backed securities 213,266 152,756 Total fixed maturity investments 2,393,352 1,587,160 Short-term investments 226,454 394,111 Total fixed income investments $ 2,619,806 $ 1,981,271 Equity securities Equity investments $ 117 $ 48 Preferred equity investments 5,966 553 Short-term fixed income fund 17,037 14,628 Total equity securities $ 23,120 $ 15,229 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $3.6 million and $38.5 million at September 30, 2016 and December 31, 2015 , respectively.
Other Investments	The following table summarizes the composition, unfunded commitments and redemption restrictions of other investments as of September 30, 2016 and December 31, 2015 : September 30, 2016 Market Value Unfunded Commitments Ineligible for Redemption over next 12 months Alternative funds Hedge funds $ 576,291 $ — $ 97,334 Private investment funds 76,665 95,846 76,665 Other investment funds 26,051 — 25,575 Total alternative funds 679,007 95,846 199,574 Total other investments $ 679,007 $ 95,846 $ 199,574 December 31, 2015 Market Value Unfunded Ineligible for Alternative funds Hedge funds $ 704,966 $ — $ 57,876 Private investment funds 80,690 102,070 80,690 Other investment funds 23,465 — 24,958 Total alternative funds 809,121 102,070 163,524 Specialty funds High yield loan funds 63,496 30,000 — Total specialty funds 63,496 30,000 — Total other investments $ 872,617 $ 132,070 $ 163,524
Net Realized And Unrealized Gains	The analysis of gross realized gains and losses, net unrealized gains (losses) on trading securities, and the change in the fair value of investment-related derivative financial instruments for the three and nine months ended September 30, 2016 and 2015 is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Gross realized gains on investment sales $ 11,072 $ 20,107 $ 35,776 $ 57,420 Gross realized losses on investment sales (3,365 ) (8,236 ) (50,537 ) (18,190 ) Net unrealized gains (losses) on trading securities 6,153 (5,037 ) 48,229 (5,037 ) Change in fair value of investment-related derivative financial instruments (1) (455 ) (1,805 ) 71 (1,295 ) Net realized and unrealized gains $ 13,405 $ 5,029 $ 33,539 $ 32,898 (1) For additional information on the Company's derivative financial instruments, see Note 7, Derivatives.
Amortized Cost, Fair Value, Gross Unrealized Gains and Losses For Available For Sale Investments	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 funds 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 . The amortized cost, fair value and related gross unrealized gains and losses on the Company's securities classified as available for sale at September 30, 2016 and December 31, 2015 are as follows: September 30, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity investments U.S. government and agencies securities $ 338,564 $ 8,551 $ (79 ) $ 347,036 U.S. state and municipal securities 10,804 125 (157 ) 10,772 Foreign government securities 82,096 2,196 (2 ) 84,290 Government guaranteed corporate securities 9,613 298 — 9,911 Corporate securities 1,096,722 24,174 (345 ) 1,120,551 Residential mortgage-backed securities 912,540 25,283 (458 ) 937,365 Commercial mortgage-backed securities 523,921 11,920 (3,268 ) 532,573 Collateralized loan and debt obligations (1) 298,990 2,239 (614 ) 300,615 Asset-backed securities 252,432 1,860 (685 ) 253,607 Total fixed maturity investments 3,525,682 76,646 (5,608 ) 3,596,720 Short-term investments 34,934 — — 34,934 Total fixed income investments $ 3,560,616 $ 76,646 $ (5,608 ) $ 3,631,654 Equity securities Equity investments $ 330,971 $ 22,347 $ (2,068 ) $ 351,250 Emerging market debt funds 83,668 4,057 — 87,725 Convertible funds 46,331 2,313 — 48,644 Preferred equity investments 7,078 1,684 (110 ) 8,652 Short-term fixed income fund 128 3 — 131 Total equity securities $ 468,176 $ 30,404 $ (2,178 ) $ 496,402 (1) Balances include amounts related to collateralized debt obligations held with total fair values of $3.2 million .
Available For Sale Securities 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 at December 31, 2015 . The following tables summarize, for all available for sale securities in an unrealized loss position at September 30, 2016 and December 31, 2015 , 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 September 30, 2016 Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Unrealized Losses (1) Fair Value Fixed maturity investments U.S. government and agencies securities $ (79 ) $ 24,932 $ — $ — $ (79 ) $ 24,932 U.S. state and municipal securities (74 ) 5,697 (83 ) 2,250 (157 ) 7,947 Foreign government securities (1 ) 1,349 (1 ) 549 (2 ) 1,898 Corporate securities (161 ) 65,619 (184 ) 19,814 (345 ) 85,433 Residential mortgage-backed securities (188 ) 29,949 (270 ) 36,070 (458 ) 66,019 Commercial mortgage-backed securities (1,356 ) 118,481 (1,912 ) 63,554 (3,268 ) 182,035 Collateralized loan and debt obligations (240 ) 18,373 (374 ) 52,084 (614 ) 70,457 Asset-backed securities (263 ) 49,423 (422 ) 31,248 (685 ) 80,671 Total fixed income investments $ (2,362 ) $ 313,823 $ (3,246 ) $ 205,569 $ (5,608 ) $ 519,392 Equity securities Equity investments $ (1,284 ) $ 15,453 $ (784 ) $ 14,222 $ (2,068 ) $ 29,675 Preferred equity investments (95 ) 1,614 (15 ) 235 (110 ) 1,849 Total equity securities $ (1,379 ) $ 17,067 $ (799 ) $ 14,457 $ (2,178 ) $ 31,524 (1) Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive income at September 30, 2016 .
Noncontrolling Interests Rollforward	The following table summarizes the movements in the non-redeemable non-controlling interests balance during the three and nine months ended September 30, 2016 and 2015 : Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Non-controlling interests, beginning of period $ 259,851 $ 258,529 $ 267,810 $ 258,529 Income attributable to third-party investments in the BCGR Cell 3,453 821 11,603 821 Income attributable to third-party investments in BCRH 2,226 1,886 6,853 1,886 Net income attributable to non-controlling interests 5,679 2,707 18,456 2,707 Net preferred share redemptions attributable to third-party investments in the BCGR Cell (1) (6,800 ) — (16,807 ) — Net investments attributable to third-parties in BCRH 20 (7 ) 53 (7 ) Net change in third-party investments in non-controlling interests (6,780 ) (7 ) (16,754 ) (7 ) Dividends declared by BCRH attributable to non-controlling interests (1,757 ) (1,755 ) (12,519 ) (1,755 ) Non-controlling interests, end of period $ 256,993 $ 259,474 $ 256,993 $ 259,474 (1) The redemption from the BCGR Cell during the three and nine months ended September 30, 2016 was required to fund expenses, repay debt and fund dividends by BCGR.

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Schedule Of Fixed Maturity Investments, Equity Securities, Short-term Investments, Securities Pledged Under Repurchase Agreements, 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, securities pledged under repurchase agreements, other assets and liabilities and debt categorized by the level within the hierarchy in which the fair value measurements fall at September 30, 2016 : Fair Value Measurements at September 30, 2016 Total at September 30, 2016 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 $ 743,504 $ 51,668 $ 691,836 $ — U.S. state and municipal securities 15,975 — 15,975 — Foreign government securities 213,076 — 213,076 — Government guaranteed corporate securities 41,437 — 41,437 — Corporate securities 2,072,074 — 1,893,278 178,796 Residential mortgage-backed securities 1,329,069 — 1,329,069 — Commercial mortgage-backed securities 714,142 — 712,448 1,694 Collateralized loan and debt obligations 393,922 — 393,865 57 Asset-backed securities 466,873 — 466,873 — Total fixed maturity investments 5,990,072 51,668 5,757,857 180,547 Equity securities Equity investments 351,367 163,412 187,955 — Emerging market debt funds 87,725 — 87,725 — Convertible funds 48,644 — 48,644 — Preferred equity investments 14,618 — 14,618 — Short-term fixed income fund 17,168 17,168 — — Total equity securities 519,522 180,580 338,942 — Short-term investments 261,388 — 261,388 — Securities pledged under repurchase agreements (see Note 10) 124,303 — 124,303 — Other assets (see Note 7) 159,273 2,331 124,373 32,569 Total assets $ 7,054,558 $ 234,579 $ 6,606,863 $ 213,116 Liabilities Other liabilities (see Note 7) $ 97,958 $ 2,942 $ 67,075 $ 27,941 Debt 799,393 — 799,393 — Total liabilities $ 897,351 $ 2,942 $ 866,468 $ 27,941 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 7) 68,892 4 27,385 41,503 Total assets $ 6,963,681 $ 312,831 $ 6,496,894 $ 153,956 Liabilities Other liabilities (see Note 7) $ 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 inputs used in determining the fair value of the net weather and energy related derivative assets and liabilities classified in Level 3 that are measured at fair value on a recurring basis at September 30, 2016 and December 31, 2015 : September 30, 2016 Fair Value (Level 3) Valuation Techniques Inputs Range Low High (Commodity curve in U.S. dollars in thousands) Net weather and energy related derivative assets $ 4,628 Historical Analysis and Simulation Correlation 0 1 Temperature -15F 115F Composite weather variable -25 deg. 45 deg. Rainfall 0" 2" Windspeed 0.01 m/s 25 m/s Wave height 0 m 25 m Commodity curve $ (1 ) $ 14 December 31, 2015 Fair Value (Level 3) Valuation Techniques Inputs Range Low High (Commodity curve in U.S. dollars in thousands) Net weather and energy related derivative liabilities $ 526 Historical Analysis and Simulation Correlation 0 1 Temperature -15F 115F Composite weather variable -25 deg. 45 deg. Rainfall 0" 2" Windspeed 0.01 m/s 25 m/s Snowfall 0" 18" Cyclone (category) 0 5 Commodity curve $ — $ 13
Reconciliation Of The Beginning And Ending Balances For All 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 three months ended September 30, 2016 and 2015 : Three Months Ended September 30, 2016 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of period $ 109,025 $ 34,357 $ 143,382 $ (21,549 ) Total realized and unrealized gains included in earnings 1,585 — 1,585 — Total realized and unrealized losses included in earnings (117 ) — (117 ) — Total income included in other underwriting (loss) income — 1,651 1,651 7,186 Total loss included in other underwriting (loss) income — (3,762 ) (3,762 ) (3,185 ) Change in unrealized gains included in other comprehensive income (loss) 60 — 60 — Change in unrealized losses included in other comprehensive income (loss) (46 ) — (46 ) — Purchases 15,004 — 15,004 — Issues — 9,378 9,378 (14,035 ) Sales (7,831 ) — (7,831 ) — Settlements — (9,055 ) (9,055 ) 3,642 Transfers into Level 3 62,867 — 62,867 — Transfers out of Level 3 — — — — Level 3, end of period $ 180,547 $ 32,569 $ 213,116 $ (27,941 ) Three Months Ended September 30, 2015 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of period $ 4,707 $ 23,691 $ 28,398 $ (22,184 ) Total realized and unrealized losses included in earnings (24 ) — (24 ) — Total income included in other underwriting (loss) income — 1,589 1,589 14,745 Total loss included in other underwriting (loss) income — (11,794 ) (11,794 ) (2,552 ) Change in unrealized gains included in other comprehensive income (loss) 85 — 85 — Change in unrealized losses included in other comprehensive income (loss) (35 ) — (35 ) — Purchases — 1,250 1,250 (737 ) Issues — 5,441 5,441 (9,058 ) Sales (237 ) — (237 ) — Settlements — — — 61 Transfers into Level 3 128,880 — 128,880 — Transfers out of Level 3 — — — — Level 3, end of period $ 133,376 $ 20,177 $ 153,553 $ (19,725 ) 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 nine months ended September 30, 2016 and 2015 : Nine Months Ended September 30, 2016 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of period $ 112,453 $ 41,503 $ 153,956 $ (42,029 ) Total realized and unrealized gains included in earnings 3,901 — 3,901 — Total realized and unrealized losses included in earnings (2,464 ) — (2,464 ) — Total income included in other underwriting (loss) income — 5,199 5,199 18,305 Total loss included in other underwriting (loss) income — (11,544 ) (11,544 ) (8,541 ) Change in unrealized gains included in other comprehensive income (loss) 384 — 384 — Change in unrealized losses included in other comprehensive income (loss) (121 ) — (121 ) — Purchases 16,678 — 16,678 — Issues — 22,964 22,964 (32,780 ) Sales (24,100 ) — (24,100 ) — Settlements — (25,553 ) (25,553 ) 37,104 Transfers into Level 3 79,332 — 79,332 — Transfers out of Level 3 (5,516 ) — (5,516 ) — Level 3, end of period $ 180,547 $ 32,569 $ 213,116 $ (27,941 ) Nine Months Ended September 30, 2015 Fixed maturity investments Other assets Total assets Other liabilities Level 3, beginning of period $ 12,290 $ 25,615 $ 37,905 $ (35,366 ) Total realized and unrealized gains included in earnings 113 — 113 — Total realized and unrealized losses included in earnings (35 ) — (35 ) — Total income included in other underwriting (loss) income — 7,184 7,184 35,610 Total loss included in other underwriting (loss) income — (24,788 ) (24,788 ) (9,772 ) Change in unrealized gains included in other comprehensive income (loss) 109 — 109 — Change in unrealized losses included in other comprehensive income (loss) (228 ) — (228 ) — Purchases — 1,250 1,250 (737 ) Issues — 17,774 17,774 (27,806 ) Sales (547 ) — (547 ) — Settlements — (6,858 ) (6,858 ) 18,346 Transfers into Level 3 130,850 — 130,850 — Transfers out of Level 3 (9,176 ) — (9,176 ) — Level 3, end of period $ 133,376 $ 20,177 $ 153,553 $ (19,725 )

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2016
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 common share for the three and nine months ended September 30, 2016 and 2015 : Three Months Ended Nine Months Ended 2016 2015 2016 2015 Numerator: Net income available to common and participating common shareholders $ 130,070 $ 43,635 $ 313,069 $ 219,944 Less amount allocated to participating common shareholders (1) (2,607 ) (1,251 ) (6,662 ) (6,442 ) Net income allocated to common shareholders $ 127,463 $ 42,384 $ 306,407 $ 213,502 Denominator: Weighted average shares - basic 66,185,375 57,923,044 65,920,276 48,453,368 Share equivalents: Options 37,597 111,760 53,438 137,366 Restricted shares 18,976 11,344 8,699 1,367 Weighted average shares - diluted 66,241,948 58,046,148 65,982,413 48,592,101 Basic earnings per common share $ 1.93 $ 0.73 $ 4.65 $ 4.41 Diluted earnings per common share $ 1.92 $ 0.73 $ 4.64 $ 4.39 (1) Represents earnings attributable to holders of unvested restricted shares and restricted share units issued under the Company's equity compensation plan 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	Three Months Ended Nine Months Ended 2016 2015 2016 2015 Dividends declared per Series A preferred share $ — $ 0.484375 $ — $ 1.453125 Dividends declared per Series B preferred share $ — $ 0.468750 $ 0.864580 $ 1.406250 Dividends declared per Series C preferred share $ 396.8750 $ — $ 1,283.2292 $ — Dividends declared per common share $ 0.38 $ 0.35 $ 1.14 $ 1.05

Accumulated Other Comprehensi29

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule Of Accumulated Other Comprehensive Income (Loss)	The following tables present the changes in accumulated other comprehensive income (loss) balances by component for the nine months ended September 30, 2016 and 2015 : For the Nine Months Ended September 30, 2016 Losses on cash flow hedges Unrealized gains (losses) on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,678 ) $ (12,638 ) $ (32,318 ) $ (46,634 ) Other comprehensive income (loss) before reclassifications — 116,722 (63,170 ) 53,552 Amounts reclassified from accumulated other comprehensive income (loss) (1) 66 21,009 — 21,075 Net current period other comprehensive income (loss) 66 137,731 (63,170 ) 74,627 Ending balance $ (1,612 ) $ 125,093 $ (95,488 ) $ 27,993 (1) All amounts are net of tax. For the Nine Months Ended September 30, 2015 Losses on cash flow hedges Unrealized gains (losses) on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,766 ) $ 86,100 $ (7,628 ) $ 76,706 Other comprehensive income (loss) before reclassifications — (35,195 ) (12,920 ) (48,115 ) Amounts reclassified from accumulated other comprehensive income (loss) (1) 66 (37,201 ) — (37,135 ) Net current period other comprehensive income (loss) 66 (72,396 ) (12,920 ) (85,250 ) Ending balance $ (1,700 ) $ 13,704 $ (20,548 ) $ (8,544 ) (1) All amounts are net of tax. The following tables present the changes in accumulated other comprehensive income (loss) balances by component for the three months ended September 30, 2016 and 2015 : For the Three Months Ended September 30, 2016 Losses on cash flow hedges Unrealized gains (losses) on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,634 ) $ 103,957 $ (82,374 ) $ 19,949 Other comprehensive income (loss) before reclassifications — 24,799 (13,114 ) 11,685 Amounts reclassified from accumulated other comprehensive income (loss) (1) 22 (3,663 ) — (3,641 ) Net current period other comprehensive income (loss) 22 21,136 (13,114 ) 8,044 Ending balance $ (1,612 ) $ 125,093 $ (95,488 ) $ 27,993 (1) All amounts are net of tax. For the Three Months Ended September 30, 2015 Losses on cash flow hedges Unrealized gains (losses) on available for sale securities Foreign currency translation adjustments Total Beginning balance $ (1,722 ) 43,610 $ (4,923 ) $ 36,965 Other comprehensive income (loss) before reclassifications — (18,258 ) (15,625 ) (33,883 ) Amounts reclassified from accumulated other comprehensive income (loss) (1) 22 (11,648 ) — (11,626 ) Net current period other comprehensive income (loss) 22 (29,906 ) (15,625 ) (45,509 ) Ending balance $ (1,700 ) $ 13,704 $ (20,548 ) $ (8,544 ) (1) All amounts are net of tax.
Reclassification Out Of Accumulated Other Comprehensive Income (Loss)	The following tables present the significant items reclassified out of accumulated other comprehensive income (loss) during the three months ended September 30, 2016 and 2015 : Three Months Ended September 30, 2016 Details about accumulated other comprehensive income (loss) components Amount reclassified from accumulated other comprehensive income (loss) Affected line item in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 22 Interest expense 22 Total before income taxes — Income tax expense $ 22 Total net of income taxes Unrealized gains on available for sale securities $ (4,476 ) Net realized and unrealized gains 183 Net impairment losses recognized in earnings (4,293 ) Total before income taxes 630 Income tax expense $ (3,663 ) Total net of income taxes Three Months Ended September 30, 2015 Details about accumulated other comprehensive Amount reclassified Affected line item in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 22 Interest expense 22 Total before income taxes — Income tax expense $ 22 Total net of income taxes Unrealized gains on available for sale securities $ (11,871 ) Net realized and unrealized gains 38 Net impairment losses recognized in earnings (11,833 ) Total before income taxes 185 Income tax expense $ (11,648 ) Total net of income taxes The following tables present the significant items reclassified out of accumulated other comprehensive income (loss) during the nine months ended September 30, 2016 and 2015 : Nine Months Ended September 30, 2016 Details about accumulated other comprehensive income (loss) components Amount reclassified from accumulated other comprehensive income (loss) Affected line item in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 66 Interest expense 66 Total before income taxes — Income tax expense $ 66 Total net of income taxes Unrealized losses on available for sale securities $ 9,620 Net realized and unrealized losses 10,647 Net impairment losses recognized in earnings 20,267 Total before income taxes 742 Income tax expense $ 21,009 Total net of income taxes Nine Months Ended September 30, 2015 Details about accumulated other comprehensive Amount reclassified Affected line item in the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income Losses on cash flow hedges - Debt $ 66 Interest expense 66 Total before income taxes — Income tax expense $ 66 Total net of income taxes Unrealized gains on available for sale securities $ (39,230 ) Net realized and unrealized gains 1,111 Net impairment losses recognized in earnings (38,119 ) Total before income taxes 918 Income tax expense $ (37,201 ) Total net of income taxes

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule Of The Fair Value And Related Notional Amounts Of Derivatives Included In The Company's Consolidated Balance Sheet	The fair values and the related notional values of derivatives at September 30, 2016 and December 31, 2015 are shown below. September 30, 2016 December 31, 2015 Fair Value Notional Principal Amount Fair Value Notional Principal Amount Derivatives recorded in other assets Foreign exchange forward contracts $ 213 $ 32,895 $ 425 $ 38,818 Credit default swaps 117 3,241 36 4,225 ILWs 2,336 20,000 — — TBAs 121,707 115,900 26,924 25,700 Energy and weather contracts 34,900 96,859 41,507 70,388 Total recorded in other assets $ 159,273 $ 68,892 Derivatives recorded in other liabilities Foreign exchange forward contracts $ 118 $ 41,736 $ 372 $ 30,400 Credit default swaps 31 2,059 276 7,800 Interest rate swaps 110 1,100 7 42,000 Interest rate futures — — 8 54,488 ILWs 733 14,209 259 19,500 LIBOR swap 114 100,000 233 100,000 TBAs 61,991 59,000 — — Loss development cover 3,978 24,426 2,904 22,322 Energy and weather contracts 30,883 153,344 42,029 148,325 Total recorded in other liabilities $ 97,958 $ 46,088 Net derivative asset $ 61,315 $ 22,804
Schedule Of The Gains And Losses On The Consolidated Statements Of Income And Comprehensive Income From Derivatives	The gains and losses on the Unaudited Condensed Consolidated Statements of Income and Comprehensive Income for derivatives for the three and nine months ended September 30, 2016 and 2015 were as follows: Three Months Ended Nine Months Ended 2016 2015 2016 2015 Total (losses) gains included in net foreign exchange (gains) losses from foreign exchange forward contracts $ (231 ) $ 155 $ (732 ) $ 1,281 Interest rate futures — (78 ) (227 ) 17 Credit default swaps 70 (143 ) (12 ) (134 ) Interest rate swaps (69 ) (705 ) (117 ) (940 ) Interest rate swaptions — 28 (27 ) 56 ILWs (958 ) (652 ) (898 ) (652 ) LIBOR swap 232 (173 ) 120 (173 ) TBAs 270 (82 ) 1,232 531 Total (losses) gains included in net realized and unrealized gains (455 ) (1,805 ) 71 (1,295 ) Energy and weather contracts 1,486 1,988 2,808 8,030 Loss development cover (618 ) (465 ) (2,104 ) (465 ) Total gains included in other underwriting (loss) income 868 1,523 704 7,565 Total gains (losses) from derivatives $ 182 $ (127 ) $ 43 $ 7,551

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Summary Of The Segment Revenues, Results And Reserve For Losses And Loss Expenses	The following table provides a summary of segment revenues and results for the three months ended September 30, 2015 and the reserve for losses and loss expenses as of September 30, 2015 : Three Months Ended September 30, 2015 Insurance Reinsurance Total Revenues Gross premiums written $ 448,563 $ 194,034 $ 642,597 Ceded premiums written (273,626 ) (32,281 ) (305,907 ) Net premiums written 174,937 161,753 336,690 Net premiums earned 234,143 322,860 557,003 Other underwriting income — 227 227 234,143 323,087 557,230 Expenses Net losses and loss expenses 139,603 124,390 263,993 Acquisition expenses 24,375 66,082 90,457 General and administrative expenses 31,880 28,913 60,793 195,858 219,385 415,243 Underwriting income $ 38,285 $ 103,702 141,987 Net investment income 16,533 Corporate expenses (74,308 ) Net foreign exchange losses (8,621 ) Net realized and unrealized gains 5,029 Net impairment losses recognized in earnings (38 ) Amortization of intangibles (11,318 ) Interest expense (12,324 ) Income before income taxes $ 56,940 Net loss ratio 59.6 % 38.5 % 47.4 % Acquisition expense ratio 10.4 % 20.5 % 16.2 % General and administrative expense ratio 13.6 % 9.0 % 24.3 % (1) Combined ratio 83.6 % 68.0 % 87.9 % Reserve for losses and loss expenses $ 2,429,385 $ 2,060,451 $ 4,489,836 (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. The following table provides a summary of segment revenues and results for the three months ended September 30, 2016 and the reserve for losses and loss expenses as of September 30, 2016 : Three Months Ended September 30, 2016 Insurance Reinsurance Total Revenues Gross premiums written $ 568,277 $ 192,410 $ 760,687 Ceded premiums written (365,573 ) (46,128 ) (411,701 ) Net premiums written 202,704 146,282 348,986 Net premiums earned 272,603 337,553 610,156 Other underwriting loss — (466 ) (466 ) 272,603 337,087 609,690 Expenses Net losses and loss expenses 202,717 128,745 331,462 Acquisition expenses 41,773 79,618 121,391 General and administrative expenses 40,658 27,080 67,738 285,148 235,443 520,591 Underwriting (loss) income $ (12,545 ) $ 101,644 89,099 Net investment income 62,236 Corporate expenses (11,952 ) Net foreign exchange gains 18,576 Net realized and unrealized gains 13,405 Net impairment losses recognized in earnings (183 ) Amortization of intangibles (21,154 ) Interest expense (10,826 ) Income before income taxes $ 139,201 Net loss ratio 74.4 % 38.1 % 54.3 % Acquisition expense ratio 15.3 % 23.6 % 19.9 % General and administrative expense ratio 14.9 % 8.0 % 13.1 % (1) Combined ratio 104.6 % 69.7 % 87.3 % Reserve for losses and loss expenses $ 2,712,403 $ 2,095,465 $ 4,807,868 (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 nine months ended September 30, 2016 : Nine Months Ended September 30, 2016 Insurance Reinsurance Total Revenues Gross premiums written $ 1,997,100 $ 1,512,194 $ 3,509,294 Ceded premiums written (1,183,850 ) (319,848 ) (1,503,698 ) Net premiums written 813,250 1,192,346 2,005,596 Net premiums earned 745,956 1,016,999 1,762,955 Other underwriting loss — (1,980 ) (1,980 ) 745,956 1,015,019 1,760,975 Expenses Net losses and loss expenses 499,104 451,798 950,902 Acquisition expenses 104,999 232,195 337,194 General and administrative expenses 108,912 86,130 195,042 713,015 770,123 1,483,138 Underwriting income $ 32,941 $ 244,896 277,837 Net investment income 117,394 Corporate expenses (35,553 ) Net foreign exchange gains 63,056 Net realized and unrealized gains 33,539 Net impairment losses recognized in earnings (10,647 ) Amortization of intangibles (63,471 ) Interest expense (33,053 ) Income before income taxes $ 349,102 Net loss ratio 66.9 % 44.4 % 53.9 % Acquisition expense ratio 14.1 % 22.8 % 19.1 % General and administrative expense ratio 14.6 % 8.5 % 13.1 % (1) Combined ratio 95.6 % 75.7 % 86.1 % (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses. 9. Segment reporting, cont'd. The following table provides a summary of the segment revenues and results for the nine months ended September 30, 2015 : Nine Months Ended September 30, 2015 Insurance Reinsurance Total Revenues Gross premiums written $ 1,653,647 $ 1,151,566 $ 2,805,213 Ceded premiums written (984,372 ) (160,114 ) (1,144,486 ) Net premiums written 669,275 991,452 1,660,727 Net premiums earned 571,467 833,530 1,404,997 Other underwriting income — 4,022 4,022 571,467 837,552 1,409,019 Expenses Net losses and loss expenses 359,598 315,453 675,051 Acquisition expenses 57,960 199,561 257,521 General and administrative expenses 89,289 81,359 170,648 506,847 596,373 1,103,220 Underwriting income $ 64,620 $ 241,179 305,799 Net investment income 90,646 Corporate expenses (99,210 ) Net foreign exchange losses (29,154 ) Net realized and unrealized gains 32,898 Net impairment losses recognized in earnings (1,111 ) Amortization of intangibles (14,496 ) Interest expense (30,445 ) Income before income taxes $ 254,927 Net loss ratio 63.0 % 37.8 % 48.1 % Acquisition expense ratio 10.1 % 23.9 % 18.3 % General and administrative expense ratio 15.6 % 9.8 % 19.2 % (1) Combined ratio 88.7 % 71.5 % 85.6 % (1) Total general and administrative expense ratio includes general and administrative expenses and corporate expenses.
Schedule Of Gross And Net Premiums Written By Line Of Business	The following table provides gross and net premiums written by line of business for the three months ended September 30, 2016 and 2015 : Gross premiums written Net premiums written Gross premiums written Net premiums written Business Segment 2016 2016 2015 2015 Insurance Agriculture $ 151,483 $ 49,062 $ 156,145 $ 29,634 Casualty and other specialty 168,644 68,211 128,509 64,490 Professional lines 97,432 30,328 80,069 37,479 Property, marine/energy and aviation 150,718 55,103 83,840 43,334 Total Insurance 568,277 202,704 448,563 174,937 Reinsurance Catastrophe 51,040 32,696 40,660 14,814 Property 41,975 40,882 53,423 52,887 Casualty 35,438 35,772 42,802 42,802 Professional lines 33,289 31,883 31,705 31,705 Specialty 30,668 5,049 25,444 19,545 Total Reinsurance 192,410 146,282 194,034 161,753 Total $ 760,687 $ 348,986 $ 642,597 $ 336,690 The following table provides gross and net premiums written by line of business for the nine months ended September 30, 2016 and 2015 : Gross premiums written Net premiums written Gross premiums written Net premiums written Business Segment 2016 2016 2015 2015 Insurance Agriculture $ 714,621 $ 254,727 $ 785,073 $ 254,771 Casualty and other specialty 484,980 209,673 375,247 174,850 Professional lines 297,526 124,866 231,565 105,153 Property, marine/energy and aviation 499,973 223,984 261,762 134,501 Total Insurance 1,997,100 813,250 1,653,647 669,275 Reinsurance Catastrophe 488,865 319,245 304,900 190,579 Property 229,087 222,242 209,683 206,454 Casualty 216,421 215,412 149,032 149,032 Professional lines 217,476 215,134 209,803 209,803 Specialty 360,345 220,313 278,148 235,584 Total Reinsurance 1,512,194 1,192,346 1,151,566 991,452 Total $ 3,509,294 $ 2,005,596 $ 2,805,213 $ 1,660,727

Commitments And Contingencies (

Commitments And Contingencies (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule Of Percentage Of Gross Premiums Written	The following table shows the percentage of gross premiums written generated through the Company's largest brokers for the nine months ended September 30, 2016 and 2015 , respectively: Broker 2016 2015 Marsh & McLennan Companies, Inc. 20.6 % 24.9 % Aon Benfield 14.4 % 15.8 % Willis Companies 9.5 % 12.8 % Total of largest brokers 44.5 % 53.5 %
Schedule Of Future Minimum Lease Commitments	Future minimum lease commitments at September 30, 2016 are as follows: Twelve months ended September 30, Amount 2017 $ 15,810 2018 16,194 2019 15,644 2020 14,874 2021 13,132 2022 and thereafter 17,425 $ 93,079
Schedule of Repurchase Agreements	The following table presents the fair value of collateral pledged under repurchase agreements by investment category. The remaining contractual maturity of the repurchase agreements is less than 30 days. September 30, 2016 Collateral pledged under repurchase agreements U.S. government and agencies securities $ 25,876 Residential mortgage-backed securities 98,427 $ 124,303 Gross amount of recognized liabilities for repurchase agreements $ 120,997

General (Details)

General (Details)	9 Months Ended
	Sep. 30, 2016
Blue Capital Reinsurance Holdings [Member]
Noncontrolling Interest [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	33.30%
Blue Capital Global Reinsurance Fund [Member]
Noncontrolling Interest [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	25.20%

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016USD ($)		Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)		Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Investments [Abstract]
Number of available for sale securities in an unrealized loss position	478			478			1,310
Number of available for sale securities in a continuous unrealized loss position for twelve months or greater	210			210			158
Unrealized losses	$ 7,800	[1]		$ 7,800	[1]		$ 72,600	[2]
Unrealized losses, 12 months or greater	4,000	[1]		4,000	[1]		$ 12,700	[2]
Net impairment losses recognized in earnings	$ 183		$ 38	$ 10,647		$ 1,111
[1]	Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive income at September 30, 2016.
[2]	Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive loss at December 31, 2015.

Investments (Composition Of Net

Investments (Composition Of Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net Investment Income [Line Items]
Investment income before investment expenses	$ 66,180	$ 20,751	$ 128,978	$ 101,695
Investment expenses	(3,944)	(4,218)	(11,584)	(11,049)
Net investment income	62,236	16,533	117,394	90,646
Fixed income investments
Net Investment Income [Line Items]
Investment income before investment expenses	41,078	36,204	118,382	96,145
Equity investments
Net Investment Income [Line Items]
Investment income before investment expenses	1,906	1,748	8,754	5,200
Other investments
Net Investment Income [Line Items]
Investment income before investment expenses	22,804	(17,716)	(201)	(1,758)
Cash and cash equivalents
Net Investment Income [Line Items]
Investment income before investment expenses	$ 392	$ 515	$ 2,043	$ 2,108

Investments (Contractual Maturi

Investments (Contractual Maturities Of Fixed Income Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale and Trading Securities [Line Items]
Due within one year, amortized cost	$ 508,899	$ 622,070
Due within one year, fair value	509,417	622,248
Due after one year through five years, amortized cost	2,005,903	2,005,456
Due after one year through five years, fair value	2,031,970	1,995,502
Due after five years through ten years, amortized cost	736,318	683,147
Due after five years through ten years, fair value	757,530	676,932
Due after ten years, amortized cost	45,303	33,168
Due after ten years, fair value	48,537	34,651
Residential mortgage-backed securities
Schedule of Available-for-sale and Trading Securities [Line Items]
No single maturity date, amortized cost	1,299,811	1,301,083
No single maturity date, fair value	1,329,069	1,311,373
Fixed income investments, fair value	1,329,069	1,311,373
Commercial mortgage-backed securities
Schedule of Available-for-sale and Trading Securities [Line Items]
No single maturity date, amortized cost	702,760	817,570
No single maturity date, fair value	714,142	812,886
Fixed income investments, fair value	714,142	812,886
Collateralized loan and debt obligations
Schedule of Available-for-sale and Trading Securities [Line Items]
No single maturity date, amortized cost	392,578	419,795
No single maturity date, fair value	393,922	405,128
Fixed income investments, fair value	393,922	405,128
Asset-backed securities
Schedule of Available-for-sale and Trading Securities [Line Items]
No single maturity date, amortized cost	464,826	510,540
No single maturity date, fair value	466,873	507,255
Fixed income investments, fair value	466,873	507,255
Fixed income investments
Schedule of Available-for-sale and Trading Securities [Line Items]
Fixed income investments, amortized cost	6,156,398	6,392,829
Fixed income investments, fair value	$ 6,251,460	$ 6,365,975

Investments (Fair Value of Trad

Investments (Fair Value of Trading Investments) (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		$ 2,393,352	$ 1,587,160
Equity securities, trading at fair value		23,120	15,229
U.S. government and agencies securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		396,468	319,674
U.S. state and municipal securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		5,203	5,559
Foreign government securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		128,786	49,861
Government guaranteed corporate securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		31,526	38,201
Corporate securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		951,523	532,192
Residential mortgage-backed securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		391,704	258,574
Commercial mortgage-backed securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		181,569	127,124
Collateralized loan and debt obligations(1)
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value	[1]	93,307	103,219
Asset-backed securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		213,266	152,756
Fixed maturity investments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		2,393,352	1,587,160
Short-term investments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		226,454	394,111
Fixed income investments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		2,619,806	1,981,271
Equity investments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Equity securities, trading at fair value		117	48
Preferred equity investments
Schedule of Trading Securities and Other Trading Assets [Line Items]
Equity securities, trading at fair value		5,966	553
Equity securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Equity securities, trading at fair value		23,120	15,229
Collateralized debt obligations
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fixed maturity investments, trading at fair value		3,600	38,500
Short-term fixed income fund
Schedule of Trading Securities and Other Trading Assets [Line Items]
Equity securities, trading at fair value		$ 17,037	$ 14,628
[1]	Balances include amounts related to collateralized debt obligations held with total fair values of $3.6 million and $38.5 million at September 30, 2016 and December 31, 2015, respectively.

Investments (Other Investments)

Investments (Other Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Other investments, market value	$ 679,007	$ 872,617
Commitments under investment fund classified within other investments	95,846	132,070
Prohibited amount under redemption requests over the next 12 months	199,574	163,524
Alternative funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value	679,007	809,121
Commitments under investment fund classified within other investments	95,846	102,070
Prohibited amount under redemption requests over the next 12 months	199,574	163,524
Hedge funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value	576,291	704,966
Commitments under investment fund classified within other investments	0	0
Prohibited amount under redemption requests over the next 12 months	97,334	57,876
Private investment funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value	76,665	80,690
Commitments under investment fund classified within other investments	95,846	102,070
Prohibited amount under redemption requests over the next 12 months	76,665	80,690
Other investment funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value	26,051	23,465
Commitments under investment fund classified within other investments	0	0
Prohibited amount under redemption requests over the next 12 months	$ 25,575	24,958
Specialty funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value		63,496
Commitments under investment fund classified within other investments		30,000
Prohibited amount under redemption requests over the next 12 months		0
High yield loan funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value		63,496
Commitments under investment fund classified within other investments		30,000
Prohibited amount under redemption requests over the next 12 months		$ 0

Investments (Other Investments

Investments (Other Investments Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Other investments, invested amount	$ 569,200	$ 737,100
Other investments, market value	679,007	872,617
Alternative funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value	$ 679,007	809,121
Hedge funds
Schedule of Equity Method Investments [Line Items]
Estimated liquidation, percentage in next 12 months	83.10%
Other investments, market value	$ 576,291	704,966
Hedge funds | Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Estimated notice period, in days	180 days
Estimated remaining liquidation period in years	2 years
Hedge funds | Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Estimated notice period, in days	30 days
Estimated remaining liquidation period in years	1 year
Private investment funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value	$ 76,665	80,690
Private investment funds | Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Estimated remaining liquidation period in years	10 years
Private investment funds | Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Estimated remaining liquidation period in years	5 years
Specialty funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value		63,496
High yield loan funds
Schedule of Equity Method Investments [Line Items]
Other investments, market value		$ 63,496
High yield loan funds | Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Estimated notice period, in days		60 days
High yield loan funds | Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Estimated notice period, in days		30 days

Investments (Net Realized and U

Investments (Net Realized and Unrealized Gains) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments [Abstract]
Gross realized gains on investment sales		$ 11,072	$ 20,107	$ 35,776	$ 57,420
Gross realized losses on investment sales		(3,365)	(8,236)	(50,537)	(18,190)
Net unrealized gains (losses) on trading securities		6,153	(5,037)	48,229	(5,037)
Change in fair value of derivative financial instruments	[1]	(455)	(1,805)	71	(1,295)
Net realized and unrealized gains		$ 13,405	$ 5,029	$ 33,539	$ 32,898
[1]	For additional information on the Company's derivative financial instruments, see Note 7, Derivatives.

Investments (Amortized Cost, Fa

Investments (Amortized Cost, Fair Value, Gross Unrealized Gains And Losses For Available For Sale Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2016		Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	$ 3,525,682		$ 4,361,997
Fixed income investments, fair value	3,596,720		4,359,019
Equity securities, cost	468,176		542,429
Equity securities, fair value	496,402		513,585
U.S. government and agencies securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	338,564		499,386
Fixed income investments, gross unrealized gains	8,551		2,561
Fixed income investments, gross unrealized losses	(79)		(3,153)
Fixed income investments, fair value	347,036		498,794
U.S. state and municipal securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	10,804		16,908
Fixed income investments, gross unrealized gains	125		120
Fixed income investments, gross unrealized losses	(157)		(181)
Fixed income investments, fair value	10,772		16,847
Foreign government securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	82,096		110,893
Fixed income investments, gross unrealized gains	2,196		803
Fixed income investments, gross unrealized losses	(2)		(581)
Fixed income investments, fair value	84,290		111,115
Government guaranteed corporate securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	9,613		19,248
Fixed income investments, gross unrealized gains	298		311
Fixed income investments, gross unrealized losses	0		(7)
Fixed income investments, fair value	9,911		19,552
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	1,096,722		1,323,276
Fixed income investments, gross unrealized gains	24,174		5,698
Fixed income investments, gross unrealized losses	(345)		(11,232)
Fixed income investments, fair value	1,120,551		1,317,742
Residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	912,540		1,041,540
Fixed income investments, gross unrealized gains	25,283		16,400
Fixed income investments, gross unrealized losses	(458)		(5,141)
Fixed income investments, fair value	937,365		1,052,799
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	523,921		689,078
Fixed income investments, gross unrealized gains	11,920		4,737
Fixed income investments, gross unrealized losses	(3,268)		(8,053)
Fixed income investments, fair value	532,573		685,762
Collateralized loan and debt obligations
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	298,990	[1]	304,915	[2]
Fixed income investments, gross unrealized gains	2,239	[1]	796	[2]
Fixed income investments, gross unrealized losses	(614)	[1]	(3,802)	[2]
Fixed income investments, fair value	300,615	[1]	301,909	[2]
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	252,432		356,753
Fixed income investments, gross unrealized gains	1,860		585
Fixed income investments, gross unrealized losses	(685)		(2,839)
Fixed income investments, fair value	253,607		354,499
Fixed maturity investments
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	3,525,682		4,361,997
Fixed income investments, gross unrealized gains	76,646		32,011
Fixed income investments, gross unrealized losses	(5,608)		(34,989)
Fixed income investments, fair value	3,596,720		4,359,019
Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	34,934		25,657
Fixed income investments, gross unrealized gains	0		28
Fixed income investments, gross unrealized losses	0		0
Fixed income investments, fair value	34,934		25,685
Fixed income investments
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, amortized cost	3,560,616		4,387,654
Fixed income investments, gross unrealized gains	76,646		32,039
Fixed income investments, gross unrealized losses	(5,608)		(34,989)
Fixed income investments, fair value	3,631,654		4,384,704
Equity investments
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	330,971		418,822
Equity securities, gross unrealized gains	22,347		6,834
Equity securities, gross unrealized losses	(2,068)		(31,875)
Equity securities, fair value	351,250		393,781
Emerging market debt funds
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	83,668		61,874
Equity securities, gross unrealized gains	4,057		0
Equity securities, gross unrealized losses	0		(5,453)
Equity securities, fair value	87,725		56,421
Convertible funds
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	46,331		46,331
Equity securities, gross unrealized gains	2,313		0
Equity securities, gross unrealized losses	0		(146)
Equity securities, fair value	48,644		46,185
Preferred equity investments
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	7,078		15,275
Equity securities, gross unrealized gains	1,684		1,946
Equity securities, gross unrealized losses	(110)		(151)
Equity securities, fair value	8,652		17,070
Short-term fixed income fund
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	128		127
Equity securities, gross unrealized gains	3		1
Equity securities, gross unrealized losses	0		0
Equity securities, fair value	131		128
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Equity securities, cost	468,176		542,429
Equity securities, gross unrealized gains	30,404		8,781
Equity securities, gross unrealized losses	(2,178)		(37,625)
Equity securities, fair value	496,402		513,585
Collateralized debt obligations
Schedule of Available-for-sale Securities [Line Items]
Fixed income investments, fair value	$ 3,200		$ 11,400
[1]	Balances include amounts related to collateralized debt obligations held with total fair values of $3.2 million.
[2]	Balances include amounts related to collateralized debt obligations held with total fair values of $11.4 million.

Investments (Available For Sale

Investments (Available For Sale Securities In An Unrealized Loss Position) (Details) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, 12 months or greater		$ (4,000)	[1]	$ (12,700)	[2]
Unrealized losses		(7,800)	[1]	(72,600)	[2]
U.S. government and agencies securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(79)	[1]	(2,175)	[2]
Fair value, less than 12 months		24,932		347,024
Unrealized losses, 12 months or greater		0	[1]	(978)	[2]
Fair value, 12 months or greater		0		16,669
Unrealized losses		(79)	[1]	(3,153)	[2]
Fair value		24,932		363,693
U.S. state and municipal securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(74)	[1]	(96)	[2]
Fair value, less than 12 months		5,697		9,662
Unrealized losses, 12 months or greater		(83)	[1]	(85)	[2]
Fair value, 12 months or greater		2,250		695
Unrealized losses		(157)	[1]	(181)	[2]
Fair value		7,947		10,357
Foreign government securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(1)	[1]	(404)	[2]
Fair value, less than 12 months		1,349		31,881
Unrealized losses, 12 months or greater		(1)	[1]	(177)	[2]
Fair value, 12 months or greater		549		3,966
Unrealized losses		(2)	[1]	(581)	[2]
Fair value		1,898		35,847
Government guaranteed corporate securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	[2]			(7)
Fair value, less than 12 months				1,692
Unrealized losses, 12 months or greater	[2]			0
Fair value, 12 months or greater				0
Unrealized losses	[2]			(7)
Fair value				1,692
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(161)	[1]	(9,222)	[2]
Fair value, less than 12 months		65,619		830,349
Unrealized losses, 12 months or greater		(184)	[1]	(2,010)	[2]
Fair value, 12 months or greater		19,814		51,024
Unrealized losses		(345)	[1]	(11,232)	[2]
Fair value		85,433		881,373
Residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(188)	[1]	(3,378)	[2]
Fair value, less than 12 months		29,949		365,082
Unrealized losses, 12 months or greater		(270)	[1]	(1,763)	[2]
Fair value, 12 months or greater		36,070		79,355
Unrealized losses		(458)	[1]	(5,141)	[2]
Fair value		66,019		444,437
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(1,356)	[1]	(6,708)	[2]
Fair value, less than 12 months		118,481		436,387
Unrealized losses, 12 months or greater		(1,912)	[1]	(1,345)	[2]
Fair value, 12 months or greater		63,554		42,246
Unrealized losses		(3,268)	[1]	(8,053)	[2]
Fair value		182,035		478,633
Collateralized loan and debt obligations
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(240)	[1]	(3,107)	[2]
Fair value, less than 12 months		18,373		224,520
Unrealized losses, 12 months or greater		(374)	[1]	(695)	[2]
Fair value, 12 months or greater		52,084		48,167
Unrealized losses		(614)	[1]	(3,802)	[2]
Fair value		70,457		272,687
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(263)	[1]	(2,624)	[2]
Fair value, less than 12 months		49,423		311,814
Unrealized losses, 12 months or greater		(422)	[1]	(215)	[2]
Fair value, 12 months or greater		31,248		12,880
Unrealized losses		(685)	[1]	(2,839)	[2]
Fair value		80,671		324,694
Fixed income investments
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(2,362)	[1]	(27,721)	[2]
Fair value, less than 12 months		313,823		2,558,411
Unrealized losses, 12 months or greater		(3,246)	[1]	(7,268)	[2]
Fair value, 12 months or greater		205,569		255,002
Unrealized losses		(5,608)	[1]	(34,989)	[2]
Fair value		519,392		2,813,413
Equity investments
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(1,284)	[1]	(31,875)	[2]
Fair value, less than 12 months		15,453		283,095
Unrealized losses, 12 months or greater		(784)	[1]	0	[2]
Fair value, 12 months or greater		14,222		0
Unrealized losses		(2,068)	[1]	(31,875)	[2]
Fair value		29,675		283,095
Emerging market debt funds
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	[2]			0
Fair value, less than 12 months				0
Unrealized losses, 12 months or greater	[2]			(5,453)
Fair value, 12 months or greater				56,421
Unrealized losses	[2]			(5,453)
Fair value				56,421
Convertible funds
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	[2]			(146)
Fair value, less than 12 months				46,185
Unrealized losses, 12 months or greater	[2]			0
Fair value, 12 months or greater				0
Unrealized losses	[2]			(146)
Fair value				46,185
Preferred equity investments
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(95)	[1]	(151)	[2]
Fair value, less than 12 months		1,614		7,361
Unrealized losses, 12 months or greater		(15)	[1]	0	[2]
Fair value, 12 months or greater		235		0
Unrealized losses		(110)	[1]	(151)	[2]
Fair value		1,849		7,361
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		(1,379)	[1]	(32,172)	[2]
Fair value, less than 12 months		17,067		336,641
Unrealized losses, 12 months or greater		(799)	[1]	(5,453)	[2]
Fair value, 12 months or greater		14,457		56,421
Unrealized losses		(2,178)	[1]	(37,625)	[2]
Fair value		$ 31,524		$ 393,062
[1]	Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive income at September 30, 2016.
[2]	Gross unrealized losses include unrealized losses on non-OTTI and non-credit OTTI securities recognized in accumulated other comprehensive loss at December 31, 2015.

Investments Investments (Noncon

Investments Investments (Noncontrolling Interests Rollforward) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Non-controlling interests, beginning of period		$ 259,851		$ 267,810
Net income attributable to non-controlling interests		5,679	$ 2,707	18,456	$ 2,707
Net change in third-party investments in non-controlling interests		(6,780)	(7)	(16,754)	(7)
Non-controlling interests, end of period		256,993	259,474	$ 256,993	259,474
Blue Capital Reinsurance Holdings [Member]
Noncontrolling Interest [Line Items]
Ownership percentage				33.30%
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Net income attributable to non-controlling interests		2,226	1,900	$ 6,853	1,900
Net investments attributable to third-parties in BCRH		(20)	0	(53)	0
Dividends declared by BCRH attributable to non-controlling interests		(1,757)	(1,755)	$ (12,519)	(1,755)
Blue Capital Global Reinsurance Fund [Member]
Noncontrolling Interest [Line Items]
Ownership percentage				25.20%
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Net income attributable to non-controlling interests		3,453	800	$ 11,603	800
Net investments attributable to third-parties in BCRH			$ 0		$ 0
Net change in third-party investments in non-controlling interests	[1]	$ (6,800)		$ (16,807)
Blue Capital Global Reinsurance Fund [Member] | Maximum [Member]
Noncontrolling Interest [Line Items]
Ownership percentage		50.00%
[1]	The redemption from the BCGR Cell during the three and nine months ended September 30, 2016 was required to fund expenses, repay debt and fund dividends by BCGR.

Fair Value Measurement (Narrati

Fair Value Measurement (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers into Level 3	$ 62,867	$ 128,880	$ 79,332	$ 130,850
Transfers out of Level 3	0	0	$ 5,516	9,176
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers out of Level 3	$ 0
Percentage of level 3 assets	3.00%		3.00%		2.20%
Fair Value, Inputs, Level 3 [Member] | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers into Level 3	$ 62,900	$ 128,900	$ 79,300	130,900
Transfers out of Level 3			$ 5,500
Fair Value, Inputs, Level 3 [Member] | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers out of Level 3				$ 9,200

Fair Value Measurement (Schedul

Fair Value Measurement (Schedule Of Fixed Maturity Investments, Equity Securities, Short-term Investments, Securities Pledged Under Repurchase Agreements, Derivative Instruments And Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets
Short-term investments	$ 261,388	$ 419,796
Securities pledged under repurchase agreements (see Note 10)	124,303
Other assets (see Note 7)	159,273	68,892
Total assets	7,054,558	6,963,681
Liabilities
Other liabilities (see Note 7)	97,958	46,088
Debt	799,393	737,974
Total liabilities	897,351	784,062
Fair Value, Inputs, Level 1 [Member]
Assets
Short-term investments	0	0
Securities pledged under repurchase agreements (see Note 10)	0
Other assets (see Note 7)	2,331	4
Total assets	234,579	312,831
Liabilities
Other liabilities (see Note 7)	2,942	0
Debt	0	0
Total liabilities	2,942	0
Fair Value, Inputs, Level 2 [Member]
Assets
Short-term investments	261,388	419,796
Securities pledged under repurchase agreements (see Note 10)	124,303
Other assets (see Note 7)	124,373	27,385
Total assets	6,606,863	6,496,894
Liabilities
Other liabilities (see Note 7)	67,075	4,059
Debt	799,393	737,974
Total liabilities	866,468	742,033
Fair Value, Inputs, Level 3 [Member]
Assets
Short-term investments	0	0
Securities pledged under repurchase agreements (see Note 10)	0
Other assets (see Note 7)	32,569	41,503
Total assets	213,116	153,956
Liabilities
Other liabilities (see Note 7)	27,941	42,029
Debt	0	0
Total liabilities	27,941	42,029
U.S. government and agencies securities
Assets
Fixed maturity investments	743,504	818,468
U.S. government and agencies securities | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	51,668	37,741
U.S. government and agencies securities | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	691,836	780,727
U.S. government and agencies securities | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	0	0
U.S. state and municipal securities
Assets
Fixed maturity investments	15,975	22,406
U.S. state and municipal securities | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	0	0
U.S. state and municipal securities | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	15,975	22,406
U.S. state and municipal securities | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	0	0
Foreign government securities
Assets
Fixed maturity investments	213,076	160,976
Foreign government securities | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	0	0
Foreign government securities | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	213,076	160,976
Foreign government securities | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	0	0
Government guaranteed corporate securities
Assets
Fixed maturity investments	41,437	57,753
Government guaranteed corporate securities | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	0	0
Government guaranteed corporate securities | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	41,437	57,753
Government guaranteed corporate securities | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	0	0
Corporate securities
Assets
Fixed maturity investments	2,072,074	1,849,934
Corporate securities | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	0	0
Corporate securities | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	1,893,278	1,739,002
Corporate securities | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	178,796	110,932
Residential mortgage-backed securities
Assets
Fixed maturity investments	1,329,069	1,311,373
Residential mortgage-backed securities | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	0	0
Residential mortgage-backed securities | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	1,329,069	1,311,373
Residential mortgage-backed securities | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	0	0
Commercial mortgage-backed securities
Assets
Fixed maturity investments	714,142	812,886
Commercial mortgage-backed securities | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	0	0
Commercial mortgage-backed securities | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	712,448	812,174
Commercial mortgage-backed securities | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	1,694	712
Collateralized loan and debt obligations
Assets
Fixed maturity investments	393,922	405,128
Collateralized loan and debt obligations | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	0	0
Collateralized loan and debt obligations | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	393,865	404,319
Collateralized loan and debt obligations | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	57	809
Asset-backed securities
Assets
Fixed maturity investments	466,873	507,255
Asset-backed securities | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	0	0
Asset-backed securities | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	466,873	507,255
Asset-backed securities | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	0	0
Fixed maturity investments
Assets
Fixed maturity investments	5,990,072	5,946,179
Fixed maturity investments | Fair Value, Inputs, Level 1 [Member]
Assets
Fixed maturity investments	51,668	37,741
Fixed maturity investments | Fair Value, Inputs, Level 2 [Member]
Assets
Fixed maturity investments	5,757,857	5,795,985
Fixed maturity investments | Fair Value, Inputs, Level 3 [Member]
Assets
Fixed maturity investments	180,547	112,453
Equity investments
Assets
Equity securities	351,367	393,829
Equity investments | Fair Value, Inputs, Level 1 [Member]
Assets
Equity securities	163,412	260,330
Equity investments | Fair Value, Inputs, Level 2 [Member]
Assets
Equity securities	187,955	133,499
Equity investments | Fair Value, Inputs, Level 3 [Member]
Assets
Equity securities	0	0
Emerging market debt funds
Assets
Equity securities	87,725	56,421
Emerging market debt funds | Fair Value, Inputs, Level 1 [Member]
Assets
Equity securities	0	0
Emerging market debt funds | Fair Value, Inputs, Level 2 [Member]
Assets
Equity securities	87,725	56,421
Emerging market debt funds | Fair Value, Inputs, Level 3 [Member]
Assets
Equity securities	0	0
Convertible funds
Assets
Equity securities	48,644	46,185
Convertible funds | Fair Value, Inputs, Level 1 [Member]
Assets
Equity securities	0	0
Convertible funds | Fair Value, Inputs, Level 2 [Member]
Assets
Equity securities	48,644	46,185
Convertible funds | Fair Value, Inputs, Level 3 [Member]
Assets
Equity securities	0	0
Preferred equity investments
Assets
Equity securities	14,618	17,623
Preferred equity investments | Fair Value, Inputs, Level 1 [Member]
Assets
Equity securities	0	0
Preferred equity investments | Fair Value, Inputs, Level 2 [Member]
Assets
Equity securities	14,618	17,623
Preferred equity investments | Fair Value, Inputs, Level 3 [Member]
Assets
Equity securities	0	0
Short-term fixed income fund
Assets
Equity securities	17,168	14,756
Short-term fixed income fund | Fair Value, Inputs, Level 1 [Member]
Assets
Equity securities	17,168	14,756
Short-term fixed income fund | Fair Value, Inputs, Level 2 [Member]
Assets
Equity securities	0	0
Short-term fixed income fund | Fair Value, Inputs, Level 3 [Member]
Assets
Equity securities	0	0
Equity securities
Assets
Equity securities	519,522	528,814
Equity securities | Fair Value, Inputs, Level 1 [Member]
Assets
Equity securities	180,580	275,086
Equity securities | Fair Value, Inputs, Level 2 [Member]
Assets
Equity securities	338,942	253,728
Equity securities | Fair Value, Inputs, Level 3 [Member]
Assets
Equity securities	$ 0	$ 0

Fair Value Measurement (Quantit

Fair Value Measurement (Quantitative Information Used As Level 3 Inputs) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Derivatives recorded in other assets, fair value	$ 159,273		$ 68,892
Derivatives recorded in other liabilities, fair value	97,958		46,088
Net weather and energy related derivative assets and liabilities	61,315		22,804
Energy Related Derivative [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Derivatives recorded in other assets, fair value	34,900		41,507
Derivatives recorded in other liabilities, fair value	30,883		42,029
Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Derivatives recorded in other assets, fair value	32,569		41,503
Derivatives recorded in other liabilities, fair value	27,941		42,029
Fair Value, Inputs, Level 3 [Member] | Energy Related Derivative [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Derivatives recorded in other assets, fair value	32,569		41,503
Derivatives recorded in other liabilities, fair value	27,941		42,029
Net weather and energy related derivative assets and liabilities	$ 4,628		$ (526)
Fair Value, Inputs, Level 3 [Member] | Simulation Valuation Technique [Member] | Maximum [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Correlation	1	1
Temperature	115F	115F
Composite Weather Variable	45 deg.	45 deg.
Rainfall	2"	2"
Windspeed	25 m/s	25 m/s
Wave Height	25 m
Snowfall		18"
Cyclone Category		5
Commodity curve	$ 14	$ 13
Fair Value, Inputs, Level 3 [Member] | Simulation Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs Assets And Liabilities Quantitative Information [Line Items]
Correlation	0	0
Temperature	-15F	-15F
Composite Weather Variable	-25 deg.	-25 deg.
Rainfall	0"	0"
Windspeed	0.01 m/s	0.01 m/s
Wave Height	0 m
Snowfall		0"
Cyclone Category		0
Commodity curve	$ (1)	$ 0

Fair Value Measurement (Reconci

Fair Value Measurement (Reconciliation Of The Beginning And Ending Balances For Fixed Maturity Investments, Other Assets and Other Liabilities Measured At Fair Value On A Recurring Basis Using Level 3 Inputs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3, beginning of period	$ 143,382	$ 28,398	$ 153,956	$ 37,905
Total realized and unrealized gains included in earnings	1,585		3,901	113
Total realized and unrealized losses included in earnings	(117)	(24)	(2,464)	(35)
Total income included in other underwriting (loss) income	1,651	1,589	5,199	7,184
Total loss included in other underwriting (loss) income	(3,762)	(11,794)	(11,544)	(24,788)
Change in unrealized gains included in other comprehensive income (loss)	60	85	384	109
Change in unrealized losses included in other comprehensive income (loss)	(46)	(35)	(121)	(228)
Purchases	(15,004)		(16,678)	(1,250)
Issues	9,378	5,441	22,964	17,774
Sales	(7,831)	(237)	(24,100)	(547)
Settlements	(9,055)	0	(25,553)	(6,858)
Transfers into Level 3	62,867	128,880	79,332	130,850
Transfers out of Level 3	0	0	(5,516)	(9,176)
Level 3, end of period	213,116	153,553	213,116	153,553
Fixed Maturity Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3, beginning of period	109,025	4,707	112,453	12,290
Total realized and unrealized gains included in earnings	1,585		3,901	113
Total realized and unrealized losses included in earnings	(117)	(24)	(2,464)	(35)
Total income included in other underwriting (loss) income	0	0	0	0
Total loss included in other underwriting (loss) income	0	0	0	0
Change in unrealized gains included in other comprehensive income (loss)	60	85	384	109
Change in unrealized losses included in other comprehensive income (loss)	(46)	(35)	(121)	(228)
Purchases	(15,004)	0	(16,678)	0
Issues	0	0	0	0
Sales	(7,831)	(237)	(24,100)	(547)
Settlements	0	0	0	0
Transfers into Level 3	62,867	128,880	79,332	130,850
Transfers out of Level 3	0	0	(5,516)	(9,176)
Level 3, end of period	180,547	133,376	180,547	133,376
Other Assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3, beginning of period	34,357	23,691	41,503	25,615
Total realized and unrealized gains included in earnings	0		0	0
Total realized and unrealized losses included in earnings	0	0	0	0
Total income included in other underwriting (loss) income	1,651	1,589	5,199	7,184
Total loss included in other underwriting (loss) income	(3,762)	(11,794)	(11,544)	(24,788)
Change in unrealized gains included in other comprehensive income (loss)		0	0	0
Change in unrealized losses included in other comprehensive income (loss)		0	0	0
Purchases	0	(1,250)	0	(1,250)
Issues	9,378	5,441	22,964	17,774
Sales	0	0	0	0
Settlements	(9,055)	0	(25,553)	(6,858)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Level 3, end of period	32,569	20,177	32,569	20,177
Other Liabilities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Level 3, beginning of period	(21,549)	(22,184)	(42,029)	(35,366)
Total realized and unrealized gains included in earnings	0		0	0
Total realized and unrealized losses included in earnings	0	0	0	0
Total income included in other underwriting (loss) income	7,186	14,745	18,305	35,610
Total loss included in other underwriting (loss) income	(3,185)	(2,552)	(8,541)	(9,772)
Change in unrealized gains included in other comprehensive income (loss)	0	0	0	0
Change in unrealized losses included in other comprehensive income (loss)	0	0	0	0
Purchases	0	(737)	0	(737)
Issues	(14,035)	(9,058)	(32,780)	(27,806)
Sales	0	0	0	0
Settlements	3,642	61	37,104	18,346
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Level 3, end of period	$ (27,941)	$ (19,725)	$ (27,941)	$ (19,725)

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - Series B Preferred Stock [Member] - $ / shares	Jun. 01, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock Redeemed or Called During Period, Shares	9,200,000
Preferred Stock, Redemption Price Per Share	$ 25
Preferred Stock, Dividends Per Share, Declared	$ 0.395830	$ 0	$ 0.468750	$ 0.864580	$ 1.406250

Earnings Per Share (Schedule Of

Earnings Per Share (Schedule Of Computing Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net income available to common and participating common shareholders		$ 130,070	$ 43,635	$ 313,069	$ 219,944
Less amount allocated to participating common shareholders	[1]	(2,607)	(1,251)	(6,662)	(6,442)
Net income allocated to common shareholders		$ 127,463	$ 42,384	$ 306,407	$ 213,502
Weighted average shares - basic		66,185,375	57,923,044	65,920,276	48,453,368
Weighted average shares - diluted		66,241,948	58,046,148	65,982,413	48,592,101
Basic earnings per common share		$ 1.93	$ 0.73	$ 4.65	$ 4.41
Diluted earnings per common share		$ 1.92	$ 0.73	$ 4.64	$ 4.39
Employee Stock Option [Member]
Share equivalents		37,597	111,760	53,438	137,366
Restricted Stock [Member]
Share equivalents		18,976	11,344	8,699	1,367
[1]	Represents earnings attributable to holders of unvested restricted shares and restricted share units issued under the Company's equity compensation plan 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 (Schedule 50

Earnings Per Share (Schedule Of Dividends Declared) (Details) - $ / shares	Jun. 01, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Dividends Declared [Line Items]
Dividends declared per common share		$ 0.38	$ 0.35	$ 1.14	$ 1.05
Series A Preferred Stock [Member]
Dividends Declared [Line Items]
Dividends declared per preferred share		0	0.484375	0	1.453125
Series B Preferred Stock [Member]
Dividends Declared [Line Items]
Dividends declared per preferred share	$ 0.395830	0	0.468750	0.864580	1.406250
Series C Preferred Stock [Member]
Dividends Declared [Line Items]
Dividends declared per preferred share		$ 396.8750	$ 0	$ 1,283.2292	$ 0

Accumulated Other Comprehensi51

Accumulated Other Comprehensive Income (Loss) (Schedule Of Changes In Accumulated Other Comprehensive Income By Component) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		$ 19,949	$ 36,965	$ (46,634)	$ 76,706
Other comprehensive income (loss) before reclassifications		11,685	(33,883)	53,552	(48,115)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	(3,641)	(11,626)	21,075	(37,135)
Other comprehensive income (loss)		8,044	(45,509)	74,627	(85,250)
Ending balance		27,993	(8,544)	27,993	(8,544)
Gains and losses on cash flow hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,634)	(1,722)	(1,678)	(1,766)
Other comprehensive income (loss) before reclassifications		0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	22	22	66	66
Other comprehensive income (loss)		22	22	66	66
Ending balance		(1,612)	(1,700)	(1,612)	(1,700)
Unrealized gains on available for sale securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		103,957	43,610	(12,638)	86,100
Other comprehensive income (loss) before reclassifications		24,799	(18,258)	116,722	(35,195)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	(3,663)	(11,648)	21,009	(37,201)
Other comprehensive income (loss)		21,136	(29,906)	137,731	(72,396)
Ending balance		125,093	13,704	125,093	13,704
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(82,374)	(4,923)	(32,318)	(7,628)
Other comprehensive income (loss) before reclassifications		(13,114)	(15,625)	(63,170)	(12,920)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	0	0	0
Other comprehensive income (loss)		(13,114)	(15,625)	(63,170)	(12,920)
Ending balance		$ (95,488)	$ (20,548)	$ (95,488)	$ (20,548)
[1]	All amounts are net of tax.

Accumulated Other Comprehensi52

Accumulated Other Comprehensive Income (Loss) (Schedule Of Reclassifications Out Of Accumulated Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 10,826	$ 12,324	$ 33,053	$ 30,445
Net realized and unrealized (gains) losses	(13,405)	(5,029)	(33,539)	(32,898)
Net impairment losses recognized in earnings	183	38	10,647	1,111
Total before income taxes	(139,201)	(56,940)	(349,102)	(254,927)
Income tax (benefit) expense	(199)	2,410	(2,570)	7,712
Total net of income taxes	(133,721)	(51,823)	(333,216)	(244,508)
Gains and losses on cash flow hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	22	22	66	66
Total before income taxes	22	22	66	66
Income tax (benefit) expense	0	0	0	0
Total net of income taxes	22	22	66	66
Unrealized gains on available for sale securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized and unrealized (gains) losses	(4,476)	(11,871)	9,620	(39,230)
Net impairment losses recognized in earnings	183	38	10,647	1,111
Total before income taxes	(4,293)	(11,833)	20,267	(38,119)
Income tax (benefit) expense	630	185	742	918
Total net of income taxes	$ (3,663)	$ (11,648)	$ 21,009	$ (37,201)

Derivatives (Schedule Of Deriva

Derivatives (Schedule Of Derivative Fair Value And Notional Amount) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	$ 159,273	$ 68,892
Derivatives recorded in other liabilities, fair value	97,958	46,088
Net derivative asset, fair value	61,315	22,804
Securities for Reverse Repurchase Agreements	0	30,000
Derivative assets traded under master netting agreements	159,300	68,900
Derivative liabilities traded under master netting agreements	$ 98,000	46,100
Maximum [Member]
Derivatives, Fair Value [Line Items]
Original term of credit default swap, in years	5 years
Minimum [Member]
Derivatives, Fair Value [Line Items]
Required Collateral Percentage	102.00%
Foreign Exchange Forward [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	$ 213	425
Derivatives recorded in other liabilities, fair value	118	372
Derivatives recorded in other assets, notional principal amount	32,895	38,818
Derivatives recorded in other liabilities, notional principal amount	41,736	30,400
Credit Default Swap [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	117	36
Derivatives recorded in other liabilities, fair value	31	276
Derivatives recorded in other assets, notional principal amount	3,241	4,225
Derivatives recorded in other liabilities, notional principal amount	2,059	7,800
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	110	7
Derivatives recorded in other liabilities, notional principal amount	1,100	42,000
Interest Rate Future [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	0	8
Derivatives recorded in other liabilities, notional principal amount	0	54,488
Industry Loss Warranty [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	2,336	0
Derivatives recorded in other liabilities, fair value	733	259
Derivatives recorded in other assets, notional principal amount	20,000	0
Derivatives recorded in other liabilities, notional principal amount	14,209	19,500
LIBOR Swap [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	114	233
Derivatives recorded in other liabilities, notional principal amount	$ 100,000	100,000
Fixed interest rate percentage	4.905%
Term of LIBOR swap	5 years
TBA [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	$ 121,707	26,924
Derivatives recorded in other liabilities, fair value	61,991	0
Derivatives recorded in other assets, notional principal amount	115,900	25,700
Derivatives recorded in other liabilities, notional principal amount	59,000	0
Loss Development Cover [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other liabilities, fair value	3,978	2,904
Derivatives recorded in other liabilities, notional principal amount	24,426	22,322
Energy and weather contracts [Member]
Derivatives, Fair Value [Line Items]
Derivatives recorded in other assets, fair value	34,900	41,507
Derivatives recorded in other liabilities, fair value	30,883	42,029
Derivatives recorded in other assets, notional principal amount	96,859	70,388
Derivatives recorded in other liabilities, notional principal amount	$ 153,344	$ 148,325

Derivatives (Schedule Of Deri54

Derivatives (Schedule Of Derivative Gains (Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	$ (455)	$ (1,805)	$ 71	$ (1,295)
Total gains included in other underwriting (loss) income	868	1,523	704	7,565
Total gains (losses) from derivatives	182	(127)	43	7,551
Foreign Exchange Forward [Member]
Derivative [Line Items]
Total (losses) gains included in net foreign exchange (gains) losses from foreign exchange forward contracts	(231)	155	(732)	1,281
Interest Rate Future [Member]
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	0	(78)	(227)	17
Credit Default Swap [Member]
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	70	(143)	(12)	(134)
Interest Rate Swap [Member]
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	(69)	(705)	(117)	(940)
Interest Rate Swaption [Member]
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	0	28	(27)	56
Industry Loss Warranty [Member]
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	(958)	(652)	(898)	(652)
LIBOR Swap [Member]
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	232	(173)	120	(173)
TBA [Member]
Derivative [Line Items]
Total (losses) gains included in net realized and unrealized gains	270	(82)	1,232	531
Energy and weather contracts [Member]
Derivative [Line Items]
Total gains included in other underwriting (loss) income	1,486	1,988	2,808	8,030
Loss Development Cover [Member]
Derivative [Line Items]
Total gains included in other underwriting (loss) income	$ (618)	$ (465)	$ (2,104)	$ (465)

Stock-Based Employee Compensa55

Stock-Based Employee Compensation And Other Stock Plans (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised		$ 9,500,000	$ 3,200,000	$ 9,500,000
Proceeds from stock options exercised	$ 0	$ 23,100,000	$ 7,700,000	$ 23,100,000
Restricted shares and RSUs, grants in period	24,250	856,629	638,217	1,360,981
Restricted shares and RSUs weighted average grant date fair value	$ 1,600,000	$ 59,400,000	$ 38,500,000	$ 89,400,000
Aggregate fair value of restricted shares and RSUs vested	0	23,000,000	41,200,000	44,700,000
Expenses related to employee stock purchase plan	$ 109,000	$ 76,000	$ 324,000	$ 220,000
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options granted	0	0	0	0
Number of options expired	0	0	0	0
Number of options vested	0	0	160,000	160,000
Number of options exercised	0	480,000	160,000	480,000
Compensation costs recognized in earnings	$ 100,000	$ 300,000	$ 700,000	$ 1,300,000
Compensation costs not yet recognized - stock options	300,000	1,300,000	300,000	1,300,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs recognized in earnings	8,200,000	28,100,000	27,400,000	45,000,000
Compensation costs not yet recognized - restricted stock	$ 34,400,000	$ 32,000,000	$ 34,400,000	$ 32,000,000

Segment Reporting (Summary Of T

Segment Reporting (Summary Of The Segment Revenues, Results And Reserve For Losses And Loss Expenses) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Gross premiums written		$ 760,687	$ 642,597	$ 3,509,294	$ 2,805,213
Ceded premiums written		(411,701)	(305,907)	(1,503,698)	(1,144,486)
Net premiums written		348,986	336,690	2,005,596	1,660,727
Net premiums earned		610,156	557,003	1,762,955	1,404,997
Other underwriting (loss) income		(466)	227	(1,980)	4,022
Total underwriting revenue		609,690	557,230	1,760,975	1,409,019
Net losses and loss expenses		331,462	263,993	950,902	675,051
Acquisition expenses		121,391	90,457	337,194	257,521
General and administrative expenses		67,738	60,793	195,042	170,648
Total underwriting expenses		520,591	415,243	1,483,138	1,103,220
Underwriting (loss) income		89,099	141,987	277,837	305,799
Net investment income		62,236	16,533	117,394	90,646
Corporate expenses		(11,952)	(74,308)	(35,553)	(99,210)
Net foreign exchange gains (losses)		18,576	(8,621)	63,056	(29,154)
Net realized and unrealized gains		13,405	5,029	33,539	32,898
Net impairment losses recognized in earnings		(183)	(38)	(10,647)	(1,111)
Amortization of intangibles		(21,154)	(11,318)	(63,471)	(14,496)
Interest expense		(10,826)	(12,324)	(33,053)	(30,445)
Income before income taxes		$ 139,201	$ 56,940	$ 349,102	$ 254,927
Net loss ratio		54.30%	47.40%	53.90%	48.10%
Acquisition expense ratio		19.90%	16.20%	19.10%	18.30%
General and administrative expense ratio	[1]	13.10%	24.30%	13.10%	19.20%
Combined ratio		87.30%	87.90%	86.10%	85.60%
Reserve for losses and loss expenses		$ 4,807,868	$ 4,489,836	$ 4,807,868	$ 4,489,836	$ 4,510,415
Insurance [Member]
Segment Reporting Information [Line Items]
Gross premiums written		568,277	448,563	1,997,100	1,653,647
Ceded premiums written		(365,573)	(273,626)	(1,183,850)	(984,372)
Net premiums written		202,704	174,937	813,250	669,275
Net premiums earned		272,603	234,143	745,956	571,467
Other underwriting (loss) income		0	0	0	0
Total underwriting revenue		272,603	234,143	745,956	571,467
Net losses and loss expenses		202,717	139,603	499,104	359,598
Acquisition expenses		41,773	24,375	104,999	57,960
General and administrative expenses		40,658	31,880	108,912	89,289
Total underwriting expenses		285,148	195,858	713,015	506,847
Underwriting (loss) income		$ (12,545)	$ 38,285	$ 32,941	$ 64,620
Net loss ratio		74.40%	59.60%	66.90%	63.00%
Acquisition expense ratio		15.30%	10.40%	14.10%	10.10%
General and administrative expense ratio		14.90%	13.60%	14.60%	15.60%
Combined ratio		104.60%	83.60%	95.60%	88.70%
Reserve for losses and loss expenses		$ 2,712,403	$ 2,429,385	$ 2,712,403	$ 2,429,385
Reinsurance [Member]
Segment Reporting Information [Line Items]
Gross premiums written		192,410	194,034	1,512,194	1,151,566
Ceded premiums written		(46,128)	(32,281)	(319,848)	(160,114)
Net premiums written		146,282	161,753	1,192,346	991,452
Net premiums earned		337,553	322,860	1,016,999	833,530
Other underwriting (loss) income		(466)	227	(1,980)	4,022
Total underwriting revenue		337,087	323,087	1,015,019	837,552
Net losses and loss expenses		128,745	124,390	451,798	315,453
Acquisition expenses		79,618	66,082	232,195	199,561
General and administrative expenses		27,080	28,913	86,130	81,359
Total underwriting expenses		235,443	219,385	770,123	596,373
Underwriting (loss) income		$ 101,644	$ 103,702	$ 244,896	$ 241,179
Net loss ratio		38.10%	38.50%	44.40%	37.80%
Acquisition expense ratio		23.60%	20.50%	22.80%	23.90%
General and administrative expense ratio		8.00%	9.00%	8.50%	9.80%
Combined ratio		69.70%	68.00%	75.70%	71.50%
Reserve for losses and loss expenses		$ 2,095,465	$ 2,060,451	$ 2,095,465	$ 2,060,451
[1]	Total general and administrative expense ratio includes general and administrative expenses and corporate expenses.

Segment Reporting (Schedule Of

Segment Reporting (Schedule Of Gross And Net Premiums Written By Line Of Business) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue from External Customer [Line Items]
Gross premiums written	$ 760,687	$ 642,597	$ 3,509,294	$ 2,805,213
Net premiums written	348,986	336,690	2,005,596	1,660,727
Insurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	568,277	448,563	1,997,100	1,653,647
Net premiums written	202,704	174,937	813,250	669,275
Agriculture Insurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	151,483	156,145	714,621	785,073
Net premiums written	49,062	29,634	254,727	254,771
Casualty And Other Specialty Insurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	168,644	128,509	484,980	375,247
Net premiums written	68,211	64,490	209,673	174,850
Professional Lines Insurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	97,432	80,069	297,526	231,565
Net premiums written	30,328	37,479	124,866	105,153
Property, Marine Energy and Aviation Insurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	150,718	83,840	499,973	261,762
Net premiums written	55,103	43,334	223,984	134,501
Reinsurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	192,410	194,034	1,512,194	1,151,566
Net premiums written	146,282	161,753	1,192,346	991,452
Catastrophe Reinsurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	51,040	40,660	488,865	304,900
Net premiums written	32,696	14,814	319,245	190,579
Property Reinsurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	41,975	53,423	229,087	209,683
Net premiums written	40,882	52,887	222,242	206,454
Casualty Reinsurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	35,438	42,802	216,421	149,032
Net premiums written	35,772	42,802	215,412	149,032
Professional Lines Reinsurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	33,289	31,705	217,476	209,803
Net premiums written	31,883	31,705	215,134	209,803
Specialty Reinsurance [Member]
Revenue from External Customer [Line Items]
Gross premiums written	30,668	25,444	360,345	278,148
Net premiums written	$ 5,049	$ 19,545	$ 220,313	$ 235,584

Commitments And Contingencies58

Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Reinsurance Recoverables	$ 1,436.3	$ 1,196
Collateral held related to ceded reinsurance agreements	479.8	321.5
Amount of letters of credit outstanding	278.7	341.6
Securities pledged as collateral obligation	111.2	108.9
Cash and investments pledged under letters of credit facility	$ 319.3	$ 383.3

Commitments And Contingencies59

Commitments And Contingencies (Schedule Of Percentage Of Gross Premiums Written) (Details)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Revenue from External Customer [Line Items]
Percentage of gross premium written	44.50%	53.50%
Aon Benfield [Member]
Revenue from External Customer [Line Items]
Percentage of gross premium written	14.40%	15.80%
Willis Companies [Member]
Revenue from External Customer [Line Items]
Percentage of gross premium written	9.50%	12.80%
Marsh & Mclennan Companies, Inc. [Member]
Revenue from External Customer [Line Items]
Percentage of gross premium written	20.60%	24.90%

Commitments And Contingencies60

Commitments And Contingencies (Deposits) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
UNITED STATES [Member]
Statutory Accounting Practices [Line Items]
Assets Held by Insurance Regulators	$ 211.1	$ 208.3

Commitments And Contingencies61

Commitments And Contingencies (Assets Held In Trust) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Blue Water Re Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	$ 405.2	$ 438.9
Blue Water Re [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	180.7	195.3
Blue Capital Re ILS Trusts [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	3.3	5.2
Endurance Reinsurance Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	806.6	94.1
Reduced Collateral Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	21.4	10.8
MUSIC Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	22.1	21.3
Lloyd's Capital Trust [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	278.6	276.8
Lloyd's Premiums Trust Funds [Member]
Assets Held In Trust [Line Items]
Assets Held-in-trust	$ 177.2	$ 231.9

Commitments And Contingencies62

Commitments And Contingencies (Lloyd's New Central Fund) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Levy Imposed As Percentage Of Premiums Written	0.35%
Additional Contribution As Percentage Of Underwriting Capacity Maximum	3.00%
Estimated Obligation To Central Fund For Annual Contribution	$ 1.2
Annual Subscription Charge As Percentage Of Premium Written	0.45%
Estimated Obligation For Annual Subscription Charges	$ 1.6

Commitments And Contingencies63

Commitments And Contingencies (Credit Agreements) (Details) - USD ($) $ in Millions	May 06, 2016	May 15, 2015	Sep. 30, 2016	Sep. 30, 2016	Mar. 23, 2016	Dec. 31, 2015	Apr. 19, 2012
Line of Credit Facility [Line Items]
Maximum borrowing capacity					$ 450		$ 700
Blue Capital Reinsurance Holdings [Member]
Line of Credit Facility [Line Items]
Term of facility		364 days
Maximum borrowing capacity	$ 20	$ 20
Line Of Credit Facility Percentage Of Annual Guarantee Fee		0.125%
Outstanding borrowings			$ 0	$ 0		$ 13
Debt Instrument, Basis Spread on Variable Rate	1.50%
Blue Capital Reinsurance Holdings [Member] | Due February 2 2016 [Member]
Line of Credit Facility [Line Items]
Repayments of Short-term Debt				4
Annual interest rate			1.33%
Blue Capital Reinsurance Holdings [Member] | Due February 22 2016 [Member]
Line of Credit Facility [Line Items]
Repayments of Short-term Debt				$ 5
Annual interest rate				1.48%
Blue Capital Reinsurance Holdings [Member] | Due March 11 2016 [Member]
Line of Credit Facility [Line Items]
Repayments of Short-term Debt				$ 4
Annual interest rate				1.51%
Blue Capital Reinsurance Holdings [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Outstanding borrowings			$ 0	$ 0
Blue Capital Global Reinsurance Fund [Member]
Line of Credit Facility [Line Items]
Term of facility		364 days
Maximum borrowing capacity	$ 20	$ 20
Line Of Credit Facility Percentage Of Annual Guarantee Fee		0.125%
Outstanding borrowings			0	0		$ 6
Debt Instrument, Basis Spread on Variable Rate	1.50%
Blue Capital Global Reinsurance Fund [Member] | Due February 1, 2016 [Member]
Line of Credit Facility [Line Items]
Repayments of Short-term Debt				$ 3
Annual interest rate				1.54%
Blue Capital Global Reinsurance Fund [Member] | Due February 12, 2016 [Member]
Line of Credit Facility [Line Items]
Repayments of Short-term Debt				$ 3
Annual interest rate				1.51%
Blue Capital Global Reinsurance Fund [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Outstanding borrowings			$ 0	$ 0

Commitments And Contingencies C

Commitments And Contingencies Commitments And Contingencies (Repurchase Agreements) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets Sold under Agreements to Repurchase [Line Items]
Payable under repurchase agreements	$ 120,997	$ 0
Maturity Less than 30 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged under repurchase agreements	124,303
Maturity Less than 30 Days [Member] | U.S. government and agencies securities
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged under repurchase agreements	25,876
Maturity Less than 30 Days [Member] | Residential mortgage-backed securities
Assets Sold under Agreements to Repurchase [Line Items]
Collateral pledged under repurchase agreements	$ 98,427

Commitments And Contingencies65

Commitments And Contingencies (Schedule Of Future Minimum Lease Commitments) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
2,017	$ 15,810
2,018	16,194
2,019	15,644
2,020	14,874
2,021	13,132
2022 and thereafter	17,425
Total	93,079
Total lease expenses under operating leases	$ 8,700	$ 10,500

Debt And Financing Arrangemen66

Debt And Financing Arrangements (Details) - USD ($) $ in Millions	Mar. 23, 2016	Sep. 30, 2016	Dec. 31, 2015	Apr. 19, 2012
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 450			$ 700
Amount of letters of credit outstanding		$ 278.7	$ 341.6
Increase to credit facility		$ 100
Used capacity fee percentage		0.40%
Commitment fee percentage		0.125%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Term of facility	5 years
Amount of letters of credit outstanding		$ 255.3	$ 329.9
Maximum [Member]
Line of Credit Facility [Line Items]
Leverage ratio		35.00%

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] $ / shares in Units, $ in Millions	Oct. 05, 2016USD ($)$ / shares
Subsequent Event [Line Items]
Percentage of outstanding ordinary shares acquired	100.00%
Share price, in cash | $ / shares	$ 93
Aggregate consideration	$ 6,304
Acquisition transaction costs	1
SOMPO [Member]
Subsequent Event [Line Items]
Termination fee	204.9
Acquisition transaction costs	$ 15.8