XL (XLGLF) 10-Q 5 Nov 15 2015 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Nov. 02, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	XL GROUP PLC
Entity Central Index Key	875,159
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		297,759,367

UNAUDITED CONSOLIDATED BALANCE

UNAUDITED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Investments:
Fixed maturities, at fair value (amortized cost: 2015, $32,207,019; 2014, $27,728,771)	$ 33,276,322	$ 29,359,034
Equity securities, at fair value (cost: 2015, $984,192; 2014, $763,833)	969,706	868,292
Short-term investments, at fair value (amortized cost: 2015, $545,979; 2014, $257,221)	546,020	256,727
Total investments available for sale	34,792,048	30,484,053
Fixed maturities, at fair value (amortized cost: 2015, $933,872; 2014, $1,180)	914,337	1,171
Short-term investments, at fair value (amortized cost: 2015, $70,883; 2014, nil)	70,886	0
Total investments trading	985,223	1,171
Investments in affiliates	1,592,841	1,637,620
Other investments	1,676,140	1,248,439
Total investments	39,046,252	33,371,283
Cash and cash equivalents	3,340,070	2,521,814
Restricted cash	147,810	0
Accrued investment income	311,679	315,964
Deferred acquisition costs and value of business acquired	1,036,260	354,533
Ceded unearned premiums	2,088,569	952,525
Premiums receivable	5,257,588	2,473,736
Reinsurance balances receivable	425,521	131,519
Unpaid losses and loss expenses recoverable	5,197,577	3,429,368
Receivable from investments sold	95,571	92,762
Goodwill and other intangible assets	2,213,688	447,952
Deferred tax asset	252,492	204,491
Other assets	1,003,446	750,872
Total assets	60,416,523	45,046,819
Liabilities:
Unpaid losses and loss expenses	25,789,541	19,353,243
Deposit liabilities	1,194,815	1,245,367
Future policy benefit reserves	4,323,748	4,707,199
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable: 2015, $3,886,297; 2014, $4,265,678)	930,834	1,155,016
Unearned premiums	7,840,331	3,973,132
Notes payable and debt	2,726,917	1,662,580
Reinsurance balances payable	2,295,890	493,230
Payable for investments purchased	154,342	42,291
Deferred tax liability	126,130	66,246
Other liabilities	1,133,467	912,749
Total liabilities	$ 46,516,015	$ 33,611,053
Commitments and Contingencies
Shareholders' Equity:
Ordinary shares, 999,990,000 authorized, par value $0.01; issued and outstanding (2015, 299,317,344; 2014, 255,182,955)	$ 2,993	$ 2,552
Additional paid in capital	9,036,407	7,359,102
Accumulated other comprehensive income	955,082	1,484,458
Retained earnings	1,943,747	1,187,639
Shareholders' equity attributable to XL Group plc	11,938,229	10,033,751
Non-controlling interest in equity of consolidated subsidiaries	1,962,279	1,402,015
Total shareholders' equity	13,900,508	11,435,766
Total liabilities and shareholders' equity	$ 60,416,523	$ 45,046,819

UNAUDITED CONSOLIDATED BALANCE3

UNAUDITED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Amortized cost of fixed maturities, available for sale	$ 32,207,019	$ 27,728,771
Cost of equity securities	984,192	763,833
Amortized cost of short-term investments, available for sale	545,979	257,221
Amortized cost of fixed maturities, trading	933,872	1,180
Amortized cost of short-term investments, trading	70,883	0
Future policy benefit reserves recoverable	$ 3,886,297	$ 4,265,678
Ordinary shares, shares authorized (in shares)	999,990,000	999,990,000
Ordinary shares, par value (in dollars per share)	$ 0.01	$ 0.01
Ordinary shares, shares issued (in shares)	299,317,344	255,182,955
Ordinary shares, shares outstanding (in shares)	299,317,344	255,182,955

UNAUDITED CONSOLIDATED STATEMEN

UNAUDITED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Revenues:
Net premiums earned	$ 2,423,552		$ 1,473,412	$ 5,839,605		$ 4,458,845
Net investment income	225,146		226,430	656,863		692,392
Realized investment gains (losses):
Total net realized gains (losses) on investments, and net unrealized gains (losses) on investments Trading - Life Funds Withheld Assets	51,407		4,341	154,265		96,267
Net realized and unrealized gains (losses) on derivative instruments	(7,903)		5,131	57,127		18,540
Income (loss) from investment fund affiliates	(3,715)		24,500	62,991		75,486
Fee income and other	7,355		10,782	23,095		31,942
Total revenues	2,569,702		1,543,332	6,677,613		5,154,662
Expenses:
Net losses and loss expenses incurred	1,464,285		859,588	3,385,307		2,518,973
Claims and policy benefits	22,579		20,101	64,047		218,987
Acquisition costs	409,173	[1]	182,882	904,486	[1]	566,915
Operating expenses	570,142		341,255	1,403,152		984,708
Foreign exchange (gains) losses	11,661		(23,348)	49,425		8,234
Loss on sale of life reinsurance subsidiary	0		0	0		666,423
Interest expense	51,929		42,851	153,034		99,877
Total expenses	2,529,769		1,423,329	5,959,451		5,064,117
Income (loss) before income tax and income (loss) from operating affiliates	39,933		120,003	718,162		90,545
Income (loss) from operating affiliates	8,196		20,021	40,326		94,044
Gain on sale of operating affiliate	0		0	340,407		0
Provision (benefit) for income tax	(37,042)		30,057	20,135		58,724
Net income (loss)	85,171		109,967	1,078,760		125,865
Non-controlling interests	57,889		37,583	100,158		77,024
Net income (loss) attributable to ordinary shareholders	$ 27,282		$ 72,384	$ 978,602		$ 48,841
Weighted average ordinary shares outstanding - basic (in thousands of shares)	301,867		264,353	282,506		270,494
Weighted average ordinary shares outstanding - diluted (in thousands of shares)	306,954		269,140	287,473		274,912
Earnings (loss) per ordinary share and ordinary share equivalent - basic (in dollars per share)	$ 0.09		$ 0.27	$ 3.46		$ 0.18
Earnings (loss) per ordinary share and ordinary share equivalent - diluted (in dollars per share)	$ 0.09		$ 0.27	$ 3.40		$ 0.18
Excluding Life Funds Withheld Assets
Revenues:
Net investment income	$ 178,560		$ 169,956	$ 512,994		$ 616,753
Realized investment gains (losses):
Net realized gains (losses) on investments sold	42,513		10,957	78,630		139,373
Other-than-temporary impairments on investments	(42,013)		(752)	(69,048)		(27,390)
Other-than-temporary impairments on investments transferred to (from) other comprehensive income	(701)		(392)	(830)		(2,097)
Life Funds Withheld Assets
Revenues:
Net investment income	46,586		56,474	143,869		75,639
Realized investment gains (losses):
Net realized gains (losses) on investments sold	53,780		2,022	174,555		2,646
Other-than-temporary impairments on investments	(2,023)		(7,494)	(10,110)		(16,265)
Net unrealized gains (losses) on investments, trading securities	(149)		0	(18,932)		0
Net realized and unrealized gains (losses) on derivative instruments	$ (126,140)		$ (201,264)	$ (116,333)		$ (218,810)
[1]	The Company has reflected the amortization of certain fair value adjustments recorded in conjunction with the Catlin Acquisition within the respective segments.

UNAUDITED CONSOLIDATED STATEME5

UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net income (loss) attributable to ordinary shareholders	$ 27,282	$ 72,384	$ 978,602	$ 48,841
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	0	0	0	424,861
Change in adjustments related to future policy benefit reserves, net of tax	40,681	51,286	127,365	(423,179)
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	(10,394)	15,172	24,293	29,145
Change in OTTI losses recognized in other comprehensive income, net of tax	2,137	5,963	13,570	10,895
Change in underfunded pension liability, net of tax	93	418	(261)	379
Change in value of cash flow hedge	12	83	119	303
Foreign currency translation adjustments, net of tax	(22,394)	(11,813)	(20,714)	(25,295)
Comprehensive income (loss)	(93,810)	97,279	449,226	544,113
Excluding Life Funds Withheld Assets
Change in net unrealized gains (losses) on investments, net of tax	(97,658)	(130,135)	(356,248)	371,945
Life Funds Withheld Assets
Change in net unrealized gains (losses) on investments, net of tax	$ (33,569)	$ 93,921	$ (317,500)	$ 106,218

UNAUDITED CONSOLIDATED STATEME6

UNAUDITED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Excluding Life Funds Withheld Assets	Life Funds Withheld Assets	Ordinary Shares	Additional Paid in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)Excluding Life Funds Withheld Assets	Accumulated Other Comprehensive Income (Loss)Life Funds Withheld Assets	Retained Earnings (Deficit)	Non-controlling Interest in Equity of Consolidated Subsidiaries
Balance, beginning of year at Dec. 31, 2013				$ 2,783	$ 7,994,100	$ 736,657			$ 1,264,093	$ 1,351,665
Issuance of ordinary shares				11	20
Buybacks of ordinary shares				(196)	(560,007)				(66,572)
Exercise of stock options				4
Exercise of stock options					5,408
Share-based compensation expense					51,354				0
Change in net unrealized gains (losses) on investments, net of tax		$ 371,945	$ 106,218				$ 371,945	$ 106,218
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	$ 424,861					424,861
Change in adjustments related to future policy benefit reserves, net of tax	(423,179)					(423,179)
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	29,145					29,145
Change in OTTI losses recognized in other comprehensive income, net of tax	10,895					10,895
Change in underfunded pension liability, net of tax	379					379
Change in value of cash flow hedge	303					303
Foreign currency translation adjustments, net of tax	(25,295)					(25,295)
Net income (loss) attributable to ordinary shareholders	48,841								48,841
Dividends on ordinary shares									(130,714)
Non-controlling interests - contributions										24,839
Non-controlling interests - distributions										0
Non-controlling interests - acquired										0
Non-controlling interests										3,216
Balance, end of year at Sep. 30, 2014	11,220,774			2,602	7,490,875	1,231,929			1,115,648	1,379,720
Balance, beginning of year at Dec. 31, 2014	11,435,766			2,552	7,359,102	1,484,458			1,187,639	1,402,015
Issuance of ordinary shares				515	1,856,253
Buybacks of ordinary shares				(78)	(228,857)				(63,334)
Exercise of stock options				4
Exercise of stock options					7,900
Share-based compensation expense					42,009				(7,163)
Change in net unrealized gains (losses) on investments, net of tax		$ (356,248)	$ (317,500)				$ (356,248)	$ (317,500)
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	0					0
Change in adjustments related to future policy benefit reserves, net of tax	127,365					127,365
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	24,293					24,293
Change in OTTI losses recognized in other comprehensive income, net of tax	13,570					13,570
Change in underfunded pension liability, net of tax	(261)					(261)
Change in value of cash flow hedge	119					119
Foreign currency translation adjustments, net of tax	(20,714)					(20,714)
Net income (loss) attributable to ordinary shareholders	978,602								978,602
Dividends on ordinary shares									(151,997)
Non-controlling interests - contributions										10,292
Non-controlling interests - distributions										(17,519)
Non-controlling interests - acquired										562,285
Non-controlling interests										5,206
Balance, end of year at Sep. 30, 2015	$ 13,900,508			$ 2,993	$ 9,036,407	$ 955,082			$ 1,943,747	$ 1,962,279

UNAUDITED CONSOLIDATED STATEME7

UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows provided by (used in) operating activities:
Net income (loss)	$ 1,078,760	$ 125,865
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Total net realized (gains) losses on investments and net unrealized (gains) losses on investments, Trading - Life Funds Withheld Assets	(154,265)	(96,267)
Net realized and unrealized (gains) losses on derivative instruments	(57,127)	(18,540)
Amortization of premiums (discounts) on fixed maturities	143,118	118,021
(Income) loss from investment and operating affiliates	(72,802)	(107,659)
Loss on sale of life reinsurance subsidiary	0	666,423
Gain on sale of ARX Holding Corp.	(340,407)	0
Share-based compensation	57,695	65,304
Depreciation	50,662	43,511
Accretion of deposit liabilities	32,098	3,136
Changes in:
Unpaid losses and loss expenses	16,169	(128,919)
Future policy benefit reserves	(208,286)	(172,234)
Funds withheld on life retrocession agreements, net	(213,749)	2,968
Unearned premiums	225,785	524,393
Premiums receivable	(334,537)	(262,435)
Unpaid losses and loss expenses recoverable	(346,847)	(230,870)
Ceded unearned premiums	(16,172)	(251,985)
Reinsurance balances receivable	(918)	(49,462)
Deferred acquisition costs and value of business acquired	(40,087)	243,391
Reinsurance balances payable	389,494	264,994
Deferred tax asset - net	(38,619)	(42,142)
Derivatives	163,663	(6,262)
Other assets	(30,670)	(44,467)
Other liabilities	39,841	(154,501)
Other	50,368	16,952
Total adjustments	(569,260)	602,160
Net cash provided by (used in) operating activities	509,500	728,025
Cash flows provided by (used in) investing activities:
Proceeds from sale of fixed maturities and short-term investments	10,568,708	4,048,233
Proceeds from redemption of fixed maturities and short-term investments	2,787,870	2,681,001
Proceeds from sale of equity securities	443,941	370,189
Purchases of fixed maturities and short term investments	(12,720,937)	(5,616,992)
Purchases of equity securities	(436,622)	(326,319)
Proceeds from sale of affiliates	163,830	231,902
Purchases of affiliates	(94,745)	(293,974)
Purchase of Catlin Group Limited, net of cash acquired	(1,020,015)	0
Proceeds from sale of life reinsurance subsidiary	0	570,000
Proceeds from sale of ARX Holding Corp.	560,552	0
Change in restricted cash	(147,810)	0
Other, net	(138,168)	(158,250)
Net cash provided by (used in) investing activities	(33,396)	1,505,790
Cash flows provided by (used in) financing activities:
Proceeds from issuance of ordinary shares and exercise of stock options	7,904	5,411
Buybacks of ordinary shares	(292,269)	(626,774)
Dividends paid on ordinary shares	(149,030)	(129,490)
Distributions to non-controlling interests	(80,641)	(41,463)
Contributions from non-controlling interests	10,292	24,839
Proceeds from the issuance of debt	980,600	0
Repayment of debt	0	(600,000)
Deposit liabilities	(79,944)	(266,542)
Net cash provided by (used in) financing activities	396,912	(1,634,019)
Effects of exchange rate changes on foreign currency cash	(54,760)	(46,894)
Increase (decrease) in cash and cash equivalents	818,256	552,902
Cash and cash equivalents beginning of year	2,521,814	1,800,832
Cash and cash equivalents end of year	3,340,070	2,353,734
Life Funds Withheld Assets
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Net realized and unrealized (gains) losses on derivative instruments	$ 116,333	$ 218,810

Basis of Preparation and Consol

Basis of Preparation and Consolidation	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Preparation and Consolidation	Basis of Preparation and Consolidation Unless the context otherwise indicates, references herein to the "Company" include XL Group plc, an Irish public limited company ("XL-Ireland"), and its consolidated subsidiaries. On May 1, 2015, the Company completed its acquisition of Catlin Group Limited and its consolidated subsidiaries ("Catlin"). Catlin, through its wholly-owned subsidiaries, provided property, casualty and specialty insurance and reinsurance coverage on a worldwide basis. The Company's consolidated results of operations include those of Catlin from May 1, 2015. See Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ," for additional information with respect to the acquisition of Catlin. These unaudited consolidated financial statements include the accounts of the Company and have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by GAAP for complete financial statements. In addition, the year-end balance sheet data was derived from audited financial statements but do not include all disclosures required by GAAP. In the opinion of management, these unaudited financial statements reflect all adjustments considered necessary for a fair statement of financial position and results of operations at the end of and for the periods presented. The results of operations for any interim period are not necessarily indicative of the results for a full year. All inter-company accounts and transactions have been eliminated. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure about contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from these estimates. For further information, see Item 8, Note 2(a), "Significant Accounting Policies - Basis of Preparation and Consolidation ," to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 . To facilitate period-to-period comparisons, certain reclassifications have been made to prior period consolidated financial statement amounts to conform to current period presentation.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies (a) Restricted Cash Restricted cash represents cash and cash equivalents that the Company is a) holding for the benefit of a third party and is legally or contractually restricted as to withdrawal or usage for general corporate purposes; and b) not replaceable by another type of asset other than cash or cash equivalents, under the terms of the Company's contractual arrangements with such third parties. Restricted cash includes cash and cash equivalents held pursuant to the terms of the Company's contractual obligations of the transaction described in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ." (b) Reinsurance During the three months ended September 30, 2014, the Company recorded $20.0 million , net of tax, to premiums earned and associated tax accruals related to reinstatement premiums due under assumed reinsurance contracts arising from unpaid losses and loss expenses reported in a prior period. We evaluated the quantitative and qualitative aspects of this correction and concluded that the impact of recognizing it was not material to the consolidated financial statements, nor is it material to previously issued consolidated financial statements in prior periods. (c) Recent Accounting Pronouncements In February 2015, the Financial Accounting Standards Board ("FASB") issued an accounting standards update concerning consolidation of certain legal entities. Under this new guidance, all legal entities are required to evaluate whether they should consolidate certain legal entities. The guidance: (1) modifies the evaluation of whether limited partnerships and similar legal entities are variable interest entities ("VIEs") or voting interest entities; (2) eliminates the presumption that a general partner should consolidate a limited partnership; (3) affects the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships; and (4) provides a scope exception from consolidation guidance for certain reporting entities. Upon adoption of the new guidance, differing requirements for performing a consolidation analysis under existing GAAP will be eliminated, and all reporting entities will now fall within the scope of the Accounting Standards Codification Subtopic 810-10, Consolidation-Overall , unless a specific exception applies. Under this Subtopic, there are only two primary models for determining whether consolidation is appropriate - a voting interest entity model, and a variable interest entity model. The guidance is effective for public business entities for annual periods beginning after December 15, 2015, and interim and annual periods thereafter, with early adoption permitted. The Company is currently evaluating the impact of this guidance. In April 2015, the FASB issued an accounting standards update concerning the presentation of deferred debt issuance costs in an entity's balance sheet. Under this new guidance, which is part of the FASB's initiative to reduce complexity in accounting standards while maintaining or improving the usefulness of the information provided to users of financial statements, debt issuance costs related to a recognized debt liability must be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. In addition, the guidance also requires that the amortization of such costs be reported as interest expense. The guidance is effective for public business entities for annual periods beginning after December 15, 2015, and interim and annual periods thereafter, with early adoption permitted for financial statements that have not been previously issued. This guidance will not have a material impact on the Company's financial condition, results of operations or cash flows. In May 2015, the FASB issued an accounting standards update concerning investments for which management estimates fair value using net asset value per share (or its equivalent) as a practical expedient. Under the guidance, such investments will no longer be reported within the fair value hierarchy. Removing those investments from the fair value hierarchy not only eliminates the diversity in practice resulting from the way in which investments measured at net asset value per share (or its equivalent) with future redemption dates are classified, but also ensures that all investments categorized in the fair value hierarchy are classified using a consistent approach. Investments that calculate net asset value per share (or its equivalent), but for which the practical expedient is not applied, will continue to be included in the fair value hierarchy. A reporting entity should continue to disclose information on investments for which fair value is measured at net asset value (or its equivalent) as a practical expedient to help users understand the nature and risks of the investments and whether the investments, if sold, are probable of being sold at amounts different from net asset value. The guidance is effective for public business entities for annual periods beginning after December 15, 2015 and interim and annual periods thereafter, with early adoption permitted. The Company is currently evaluating the impact of this guidance, but it is not expected to have a material impact on the Company's financial condition, results of operations or cash flows. In May 2015, the FASB issued an accounting standards update concerning the annual disclosure regarding the liability for unpaid claims and claims adjustment expenses for insurance entities. The guidance requires: (1) incurred and paid claims development information by accident year, on a net basis after reinsurance, for the number of years for which claims incurred typically remain outstanding, including the most recent reporting period, which need not exceed 10 years; (2) a reconciliation of incurred and paid claims development information to the aggregate carrying amount of the liability for unpaid claims and claim adjustment expenses, with separate disclosure of reinsurance recoverable on unpaid claims for each period presented in the statement of financial position; (3) for each accident year for which incurred claims development information is presented, the total of incurred but not reported ("IBNR") liabilities plus expected development on reported claims included in the liability for unpaid claims and claims adjustment expenses, accompanied by a description of reserving methodologies; (4) for each accident year for which incurred claims development information is presented, quantitative information about claim frequency (unless it is impracticable to do so) accompanied by a qualitative description of methodologies used for determining claim frequency information; and (5) for all claims, the average annual percentage payout of incurred claims by age for the same number of accident years as the disclosure for IBNR. The guidance recommends that insurance entities aggregate or disaggregate those disclosures so that useful information is not obscured by either the inclusion of a large amount of insignificant detail or the aggregation of items that have significantly different characteristics. The amendments also require insurance entities to disclose information about significant changes in methodologies and assumptions used to calculate the liability for unpaid claims and claim adjustment expenses, including reasons for the change and the effects on the financial statements. Additionally, the amendments require insurance entities to disclose for annual and interim reporting periods a rollforward of the liability for unpaid claims and claims adjustment expenses. Additional disclosures about liabilities for unpaid claims and claim adjustment expenses reported at present value include: (1) for each period presented in the statement of financial position, the aggregate amount of discount for the time value of money deducted to derive the liability for unpaid claims and claim adjustment expenses; (2) for each period presented in the statement of income, the amount of interest accretion recognized; and (3) the line items in the statement of income in which interest accretion is classified. The guidance is effective for public business entities for annual periods beginning after December 15, 2015 and interim periods within annual periods after December 15, 2016. Early adoption is permitted. The Company is currently evaluating the impact of this guidance, but it is not expected to have a material impact on the Company's financial condition, results of operations or cash flows. In September 2015, the FASB issued an accounting standards update concerning the accounting for measurement period adjustments following the completion of a business combination. The measurement period ends as soon as the acquirer receives the information it was seeking about facts and circumstances that existed as of the acquisition date or learns that more information is not obtainable; however, it shall not exceed one year from the acquisition date. Currently under GAAP, during the measurement period the acquirer shall recognize such adjustments to the provisional amounts as if the accounting for the business combination had been completed at the acquisition date, with a corresponding adjustment to goodwill, in the reporting period in which the adjustments are determined. The acquirer shall revise comparative information for prior periods presented in financial statements as needed as a result of the change to the provisional amounts calculated. Under the new guidance, although such adjustments shall still be calculated as if the accounting had been completed at the business combination date, the acquirer should recognize in its current-period earnings the cumulative effect of changes in depreciation, amortization, or other income effects, by line item, related to the periods subsequent to the acquisition date as a result of the adjustments. In addition, entities must present separately on the face of the income statement, or alternatively in the notes to the financial statements, the portion of such current period adjustments that would have been recorded in previous reporting periods, if the adjustments had been recognized at the acquisition date. The guidance is effective for provisional adjustments made by public business entities in annual periods beginning after December 15, 2015 - irrespective of the date of the business combination to which they relate - including interim periods within those fiscal years. Early adoption is permitted for financial statements that have not yet been made available for issuance. To the extent that the Company were to make material measurement period adjustments to provisional amounts recognized as part of the Catlin Acquisition, this could have a material impact on the Company's results of operations during the period in which such adjustments were made. The guidance is not expected to have a material impact on the Company's financial condition or cash flows.

Acquisition and Disposals

Acquisition and Disposals	9 Months Ended
	Sep. 30, 2015
Acquisition and Disposal [Abstract]
Acquisition and Disposals	Acquisitions and Disposals (a) Allied Acquisition On August 11, 2015, the Company announced that X.L. America, Inc., an indirect, wholly-owned subsidiary of XL-Ireland ("XLA") had entered into a definitive agreement to acquire Allied International Holdings, Inc. and its subsidiaries ("Allied"). Allied, through its subsidiaries, provides property and casualty insurance coverage for the amusement and entertainment industry in the United States. The transaction is expected to close no later than the first quarter of 2016, and is subject to receipt of regulatory approvals and satisfaction of customary closing conditions. (b) New Energy Risk On July 24, 2015, the Company purchased, at arm's length, an additional 63.63% interest in New Energy Risk Inc. ("New Energy"), a provider of insurance risk management solutions within the alternative energy sector. A substantial portion of the additional shares were purchased directly from the family trusts of a Company employee who is responsible for managing the business generated by New Energy. Prior to the additional purchase, the Company held a 31.16% ownership interest in New Energy, which was accounted for as an equity method investment. The subsequent purchase raised the Company's ownership stake to 94.79% , which is deemed a controlling financial interest, and hence, the Company now consolidates New Energy. Subsequent to the additional purchase, the family trusts of the employee contributed their remaining 5.21% ownership interest in New Energy to XL Innovate Fund, LP ("XL Innovate Fund"), the entity that holds the Company's New Energy shares, in partial satisfaction of the employee's aggregate 5.21% investment commitment to the Fund. See Note 11, "Related Party Transactions " for further details of these transactions. The Company paid approximately $8.8 million to acquire the additional interest in New Energy, and realized a gain of approximately $2.5 million , included within income from operating affiliates, in order to the reflect the appropriate fair value adjustment to its existing investment previously accounted for under the equity method. The assets and liabilities of New Energy are now reflected in the consolidated financial statements of the Company based on their fair value as of the acquisition date, while Goodwill of approximately $13.4 million was recorded in conjunction with the transaction. See Note 8, "Goodwill and Other Intangible Assets " for a further discussion of the goodwill recorded in conjunction with the acquisition. (c) Catlin Acquisition Overview On May 1, 2015 (the "Acquisition Date"), the Company completed its acquisition (the "Catlin Acquisition") of the entire issued share capital of Catlin as contemplated by the Implementation Agreement, dated January 9, 2015 (the "Implementation Agreement"), by and among XL-Ireland, Green Holdings Limited, a wholly-owned subsidiary of the Company ("Green Holdings"), and Catlin. Pursuant to the terms of the Implementation Agreement, the Catlin Acquisition was implemented by way of a scheme of arrangement (the "Scheme") under Section 99 of the Companies Act 1981 of Bermuda, as amended (the "Companies Act"), and sanctioned by the Supreme Court of Bermuda (the "Court"). Immediately after such Court action, Catlin was merged with and into Green Holdings under Section 104H of the Companies Act, with Green Holdings as the surviving company, pursuant to the terms of that certain Merger Agreement, dated January 9, 2015 (the "Merger Agreement"), among XL-Ireland, Green Holdings and Catlin. Pursuant to the terms of the Implementation Agreement, XL-Ireland acquired each ordinary share of Catlin, par value $0.01 per share ("Catlin Shares"), for consideration per Catlin Share (the "Acquisition Consideration") equal to 388 pence in cash and 0.130 of an XL-Ireland ordinary share, par value $0.01 per share ("XL Shares"), subject to the mix and match facility set forth in the Implementation Agreement. The newly-issued XL Shares are listed on the New York Stock Exchange. The XL Shares issued in connection with the Catlin Acquisition were issued in reliance upon the exemption from registration under the U.S. Securities Act of 1933, as amended (the "Securities Act"), provided by Section 3(a)(10) of the Securities Act. XL-Ireland issued approximately 49.9 million XL Shares and paid approximately £1.49 billion in cash to the holders of Catlin Shares as Acquisition Consideration pursuant to the terms of the Scheme. The foregoing description of the Implementation Agreement and the Merger Agreement is qualified in its entirety by reference to the full text of the Implementation Agreement and Merger Agreement, copies of which were filed on Form 8-K on January 9, 2015. In connection with the Catlin Acquisition, on January 9, 2015, the Company announced that it was relying on £1.6 billion of debt to be provided under a bridge facility entered into by XLIT Ltd., a wholly-owned subsidiary of the Company ("XL-Cayman"), and arranged by Morgan Stanley Senior Funding, Inc. and Goldman Sachs Bank USA (the "Bridge Facility") for the purposes of discharging the cash component of the Acquisition Consideration. The Company subsequently terminated the commitments under the Bridge Facility as of April 8, 2015, due to a sufficient amount in escrow to discharge the cash portion of the Acquisition Consideration. Costs related to maintaining the Bridge Facility are discussed in "Transaction-related Costs" below. In addition, on January 9, 2015, the Company entered into deal contingent deliverable foreign exchange forwards ("FX Forwards") with Morgan Stanley Capital Services LLC and Goldman Sachs International. The purpose of the FX Forwards was to mitigate risk of foreign currency exposure related to the Catlin Acquisition. Following the closing of the Catlin Acquisition, the FX Forwards were settled. Acquisition Consideration The calculation of the consideration transferred to acquire Catlin Shares is as follows: (In thousands, except per share data) Catlin Shares outstanding as of April 30, 2015 that received share consideration (including the dilutive effect of warrants) 384,118 Exchange ratio per the Implementation Agreement 0.130 XL Share issuance to Catlin shareholders 49,935 Closing price per XL share on April 30, 2015 (1) $ 37.08 XL Share issuance consideration $ 1,851,601 Catlin Shares outstanding as of April 30, 2015 that received cash consideration (including the dilutive effect of warrants) 384,118 Cash price component, per Catlin Share in GBP £ 3.88 Cash consideration, in GBP £ 1,490,377 Foreign exchange rate: GBP/USD on April 30, 2015 $ 1.5349 Cash consideration $ 2,287,579 Total acquisition consideration $ 4,139,180 ____________ (1) The closing market price of XL Shares on the Acquisition Date represents the fair value of XL shares issued as part of the Acquisition Consideration. The Company financed the $2.29 billion cash portion of the Acquisition Consideration by issuing $1.0 billion of subordinated debt, the proceeds (net of debt issuance costs) of which were $980.6 million , and the remaining $1.31 billion by using cash and cash equivalents on hand. See Note 10, "Notes Payable and Debt and Financing Arrangements ," for further information on the debt issuance. Fair Value of Net Assets Acquired and Liabilities Assumed The purchase price was allocated to the acquired assets and assumed liabilities of Catlin based on estimated fair values on the Acquisition Date. The Company recognized goodwill of $778.0 million which is primarily attributable to the synergies and economies of scale expected to result upon integration of Catlin into the Company's operations, including further diversification in geographic mix and product offerings and an increase in distribution strength. The Company has not completed the assignment of goodwill to reporting units for the reporting period ended September 30, 2015 . The Company estimates that none of the goodwill that was recorded will be deductible for income tax purposes. The Company also recognized indefinite lived intangible assets of $673.0 million and other intangible assets of $315.0 million , which will be amortized over their estimated useful lives. See Note 8, "Goodwill and Other Intangible Assets ," for further information. The foregoing allocation of the purchase price is based on information that was available to management at the time the consolidated financial statements were prepared. The allocation may change as additional information becomes available within the measurement period, which cannot exceed 12 months from the Acquisition Date. The fair value recorded for these items may be subject to adjustments, which may impact the individual amounts recorded for assets acquired and liabilities assumed, as well as the residual goodwill. The following table summarizes the fair values of the assets acquired and liabilities assumed at the Acquisition Date: (U.S. dollars in thousands) ASSETS Fixed maturities, at fair value $ 6,266,489 Short-term investments, at fair value 634,599 Equity investments, at fair value 236,230 Investment in affiliates 216,843 Other investments 386,828 Total investments $ 7,740,989 Cash and cash equivalents (1) 1,267,565 Accrued investment income 35,063 Premiums receivable 2,545,188 Unpaid losses and loss expenses recoverable 1,493,267 Reinsurance balances receivable 299,579 Ceded unearned premiums 1,143,852 Deferred acquisition costs and value of business acquired 679,259 Intangible assets 988,000 Receivable from investments sold 9,633 Other assets 314,168 Total assets $ 16,516,563 LIABILITIES Unpaid losses and loss expenses $ 6,933,144 Unearned premiums 3,742,234 Reinsurance balances payable 1,441,749 Notes payable and debt 82,066 Payable for investments purchased 34,149 Deferred tax liability 94,071 Other liabilities 265,728 Total liabilities $ 12,593,141 Net assets acquired before non-controlling interest $ 3,923,422 Non-controlling interest in equity of consolidated subsidiaries 562,285 Net assets acquired $ 3,361,137 Acquisition Consideration $ 4,139,180 Goodwill $ 778,043 ____________ (1) Includes Restricted Cash An explanation of the significant adjustments to the components of fair value are as follows: • Deferred acquisition costs and value of business acquired - The adjustment consists of two components. The first adjustment is the elimination of Catlin's deferred acquisition costs asset. The second adjustment is the establishment of the value of business acquired asset, which represents the present value of the expected underwriting profit within the unearned premiums liability, net of reinsurance, less costs to service the related policies and a risk premium. This adjustment will be amortized to underwriting, acquisition and insurance expenses over approximately two years , as the contracts for business in-force as of the Acquisition Date expire. The Company has included $140.4 million and $323.7 million , respectively, in acquisition expenses related to the amortization of the value of business acquired during the three and nine months ended September 30, 2015 . • Intangible assets - Establish the estimated fair value of intangible assets related to Catlin. See Note 8, "Goodwill and Other Intangible Assets ," for further information. • Other assets - Establish the estimated fair value of Catlin's internally developed software. • Unpaid losses and loss adjustment expenses - Unpaid losses and loss adjustment expenses acquired include an increase to adjust the carrying value of Catlin's historical unpaid losses and loss adjustment expenses, net of related reinsurance recoverable, to fair value as of the Acquisition Date. The estimated fair value consists of the present value of the expected net loss and loss adjustment expense payments plus a risk premium. This adjustment, plus the unamortized fair value adjustment included in Catlin's historical unpaid losses and loss adjustment expenses, will be amortized to losses and loss adjustment expenses over a weighted average period of approximately 20 years , based on the estimated payout pattern of net reserves as of the Acquisition Date. • Net deferred tax liabilities - The adjustment to deferred tax liabilities is related to the deferred tax impact of the adjustments to fair value as noted above. This net increase of deferred tax liabilities is explained further in "Income Taxes" below. • Non-controlling interest - The fair value was determined based on the last trade price of preferred shares issued by Catlin Insurance Company Limited ("Catlin-Bermuda"). See Note 9, "Share Capital ," for further information. Income Taxes As part of the allocation of the purchase price, the Company recorded a total net deferred tax liability of $ 94.1 million . This is the combination of an excess of gross tax liabilities over gross tax assets by $22.1 million , and a valuation allowance of $72.0 million across several jurisdictions. The $94.1 million total net deferred tax liability is comprised of a deferred tax liability of $133.8 million related to the estimated fair value of the intangible assets recorded at the Acquisition Date, partially offset by deferred tax assets, net of associated valuation allowances, of $17.4 million related to loss carry forwards, $13.0 million related to fixed assets, and $8.8 million related to the fair value measurements of unpaid losses and loss adjustment expenses, and deferred acquisition costs and the value of business acquired. The remaining $0.5 million of deferred tax assets relates primarily to differences between financial reporting and tax bases of the other acquired assets and liabilities as of the Acquisition Date. As a result of the Catlin Acquisition, the Company's expected full year effective tax rate has been determined using a single rate approach taking into account the full year expected results, including the post-acquisition results of the acquired businesses. In order to align all U.S. regulated entities under XLA, XLA purchased 100% of the stock of Catlin Inc. from Catlin North America Holdings, Ltd, a U.K. holding company, on September 28, 2015. The transaction resulted in a release of the $47.5 million valuation allowance previously held against the Catlin Inc. deferred tax asset. The Company incorporated $17.8 million of the associated tax benefit in its determination of the expected full year effective tax rate, with the remaining $29.7 million tax benefit reported as a discrete item in the period. Transaction-related Costs The Company incurred certain acquisition and financing costs associated with the Catlin Acquisition. The Company has recorded $63.0 million of these costs for the nine months ended September 30, 2015 , of which $48.5 million has been included in Operating Expense and $14.5 million has been included in Interest Expense. Transaction costs included in Operating Expense primarily consist of due diligence, legal, advisory and investment banking costs. Transaction costs included in Interest Expense related to the maintenance of the Bridge Facility. Pursuant to the terms of the Implementation Agreement, Catlin was required to pay its own costs and expenses in relation to the negotiation, preparation, execution and implementation of the Catlin Acquisition. Costs incurred by Catlin were recorded and paid by Catlin prior to the Acquisition Date and are not included within the Company's consolidated statements of income and comprehensive income. As a part of the ongoing integration of Catlin's operations, the Company incurs costs associated with restructuring the systems, processes and workforce. These costs include such items as severance, retention, facilities and consulting and other costs. The Company separately identifies such costs and includes these expenses within Corporate and Other: (U.S. dollars in thousands) Severance related costs Retention and other compensation costs Facilities-related costs Consulting and other Costs incurred in 2015 $ 27,778 $ 16,363 $ 6,689 $ 32,215 2015 payments 14,078 7,343 6,689 23,723 Liabilities at September 30, 2015 $ 13,700 $ 9,020 $ — $ 8,492 Financial Results The following table summarizes the financial results of the acquired legal entity Catlin subsidiaries since the Acquisition Date that have been included within the Company's consolidated statements of income and comprehensive income as required by ASC 805-10-50-2(h) based on legal entity reporting. These results are not used as a part of management analysis of the financial results and performance of the Company's business. These results are adjusted, where possible, for transaction and integration related costs. These results involve a significant amount of estimates and are not indicative of future results of the acquired Catlin subsidiaries, which will be further impacted by potential changes in targeted business mix, investment management strategies, and synergies recognized from changes in the combined entity's operating structure, as well as the impact of changes in other business and capital management strategies. Since the Acquisition Date, a growing number of underlying policies have been underwritten onto different legal entities, staffing has been allocated to new divisions and activities, and reinsurance has been purchased to cover combined risks, only some of which would have been reflected in the underlying legacy Catlin infrastructure, systems and general ledgers of the acquired Catlin subsidiaries. In future quarters, the summary results of such subsidiaries will be increasingly impractical to produce and even less indicative of the results of the acquired Catlin operations given the significant estimates involved and the nature and pace of our integration activities which are intended to promote the operation of the consolidated group as a whole as quickly as possible. (U.S. dollars in thousands) May 1, 2015 to September 30, 2015 Total revenues - see comments above $ 1,770,886 Net income (loss) - see comments above $ 65,796 Supplemental Pro Forma Information The results of the acquired Catlin operations have been included in the Company's unaudited consolidated financial statements from the Acquisition Date to September 30, 2015 . The following table presents unaudited pro forma consolidated information for the nine months ended September 30, 2015 and 2014 and assumes the Catlin Acquisition occurred on January 1, 2014. The pro forma financial information is presented for informational purposes only and does not necessarily reflect the results that would have occurred had the acquisition taken place on January 1, 2014, nor is it necessarily indicative of future results. Significant adjustments used to determine pro forma results include amortization of intangible assets and amortization of fair value adjustments discussed above, and the corresponding income tax effects. Non-recurring transaction related costs noted above have been included in the unaudited pro forma results for the nine months ended September 30, 2014 . Unaudited Pro Forma Nine Months Ended September 30, (In thousands, except per share data) 2015 2014 Total revenues $ 7,997,602 $ 8,391,849 Net income attributable to ordinary shareholders 986,918 226,983 Earnings (loss) per ordinary share and ordinary share equivalent – basic 3.24 0.71 Earnings (loss) per ordinary share and ordinary share equivalent – diluted 3.19 0.70 (d) Sale of Strategic Operating Affiliate On April 1, 2015, XL Re Ltd ("XL Re"), an indirect wholly-owned subsidiary of the Company, completed the previously announced sale of all of its shares in ARX Holding Corp. ("ARX") to The Progressive Corporation ("Progressive") pursuant to the terms of the Stock Purchase Agreement with Progressive. XL Re's shares in ARX represented approximately 40.6% of ARX's outstanding capital stock on a fully diluted basis at the time of the announcement. The carrying value of XL Re's shares in ARX was $220.2 million at the time of the sale. XL Re received $560.6 million in proceeds from the transaction, which was based upon the consolidated tangible net book value of ARX and its subsidiaries as of December 31, 2014 , and certain other factors. Thus, the Company recorded a gain of $340.4 million as a result of this transaction that is reflected in the unaudited consolidated statement of income for the nine months ended September 30, 2015 . (e) Sale of Life Reinsurance Subsidiary On May 1, 2014, a wholly owned subsidiary of the Company, XL Insurance (Bermuda) Ltd ("XLIB"), entered into a sale and purchase agreement with GreyCastle Holdings Ltd. ("GreyCastle") providing for the sale of 100% of the common shares of XLIB's wholly-owned subsidiary, XL Life Reinsurance (SAC) Ltd ("XLLR"), to GreyCastle for $570 million in cash (subsequent to the transaction, XLLR changed its name to GreyCastle Life Reinsurance (SAC) Ltd ("GCLR")). This transaction closed on May 30, 2014. As a result of the transaction, the Company ceded the majority of its life reinsurance business to GCLR via 100% quota share reinsurance (the "Life Retro Arrangements"). This transaction covered a substantial portion of our life reinsurance reserves. The Company ceased writing new life reinsurance contracts in 2009 and since that time has been managing the run-off of its life reinsurance operations ("Run-Off Life Operations"). The designated investments that support the Life Retro Arrangements on a funds withheld basis ("Life Funds Withheld Assets") are managed pursuant to agreed investment guidelines that meet the contractual commitments of the Company's ceding subsidiaries and applicable laws and regulations. All of the investment results associated with the Life Funds Withheld Assets ultimately accrue to GCLR. Because the Company no longer shares in the risks and rewards of the underlying performance of the supporting invested assets, disclosures within the financial statement notes included herein separate the Life Funds Withheld Assets from the rest of the Company's investments. As of May 30, 2014, gross future policy benefit reserves relating to the Life operations were approximately $5.2 billion . Subsequent to the completion of the GreyCastle transaction, the Company retained approximately $0.4 billion of these reserves, and recorded a reinsurance recoverable from GCLR of $4.8 billion . Under the terms of the transaction, the Company continues to own, on a funds withheld basis, assets supporting the Life Retro Arrangements consisting of cash, fixed maturity securities and accrued interest. Based upon the right of offset, the funds withheld liability owing to GCLR is recorded net of future policy benefit reserves recoverable, and is included within "Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)" on the consolidated balance sheets. The transaction resulted in an overall after-tax GAAP net loss of $621.3 million that is reflected in the unaudited consolidated statements of income for the nine months ended September 30, 2014. As of September 30, 2015 , gross future policy benefit reserves relating to the Run-Off Life Operations were approximately $4.3 billion , of which the Company retained approximately $0.4 billion , after consideration of its future policy benefit reserves recoverable from GCLR of approximately $3.9 billion . The net funds withheld liability included within "Funds withheld on life retrocession arrangements, net of future policy benefit reserves recoverable," was $0.9 billion . The Company continued to own $4.8 billion of assets supporting the Life Retro Arrangements. The impact of the Life Retro Arrangements on the Company's results was as follows: Impact of Life Retro Arrangements Three months ended September 30, Nine Months Ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Underwriting profit (loss) (1) $ — $ 3,711 $ 603 $ 3,711 Net investment income - Life Funds Withheld Assets 46,586 56,474 143,869 75,639 Net realized gains (losses) on investments sold - Life Funds Withheld Assets 53,780 2,022 174,555 2,646 Net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets (149 ) — (18,932 ) — OTTI on investments - Life Funds Withheld Assets (2,023 ) (7,494 ) (10,110 ) (16,265 ) Exchange gains (losses) 8,754 2,062 (5,932 ) 2,062 Other income and expenses (121 ) 124 2,354 105 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets (126,140 ) (201,264 ) (116,333 ) (218,810 ) Net income (loss) $ (19,313 ) $ (144,365 ) $ 170,074 $ (150,912 ) Change in net unrealized gains (losses) on investments - Life Funds Withheld Assets, net of tax (33,569 ) 93,921 (317,500 ) 106,218 Change in adjustments related to future policy benefit reserves, net of tax 40,681 51,286 127,365 51,286 Change in cumulative translation adjustment - Life Funds Withheld Assets, net of tax 12,201 2,869 20,664 (2,881 ) Total changes to other comprehensive income as a result of Life Retro Arrangements $ 19,313 $ 148,076 $ (169,471 ) $ 154,623 Comprehensive income (loss) $ — $ 3,711 $ 603 $ 3,711 ____________ (1) The underwriting profit of $0.6 million relates to a premium adjustment during the nine months ended September 30, 2015 relating to the Life Retro Arrangements transaction. Excluding this transaction, the impact to comprehensive income relating to the Life Retro Arrangements was nil for the nine months ended September 30, 2015. As shown in the table above, although the Company's net income (loss) is subject to variability related to the Life Retro Arrangements, there is minimal net impact on the Company's comprehensive income in any period. The life retrocession embedded derivative value includes the interest income, unrealized gains and losses, and realized gains and losses from sales on the Life Funds Withheld Assets subsequent to May 30, 2014.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the amount that would be received for the sale of an asset or paid to transfer a liability (an exit price), in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants as of the measurement date. Applicable accounting guidance provides an established hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs that market participants would use in valuing the asset or liability and are developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the factors that market participants would use in valuing the asset or liability. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. The Company reviews the fair value hierarchy classification on a quarterly basis. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy. The fair values for available for sale investments are generally sourced from third parties. The fair value of fixed income securities is based upon quoted market values where available, "evaluated bid" prices provided by third party pricing services ("pricing services") where quoted market values are not available, or by reference to broker quotes where pricing services do not provide coverage for a particular security. While the Company receives values for the majority of the investment securities it holds from pricing services, it is ultimately management’s responsibility to determine whether the values received and recorded in the financial statements are representative of appropriate fair value measurements. The Company performs regular reviews of the prices received from its third party valuation sources to assess if the prices represent a reasonable estimate of the fair value. This process is completed by investment and accounting personnel who are independent of those responsible for obtaining the valuations. The approaches taken by the Company include, but are not limited to, annual reviews of the controls of the external parties responsible for sourcing valuations, which are subjected to automated tolerance checks, quarterly reviews of the valuation sources and dates, and monthly reconciliations between the valuations provided by our external parties and valuations provided by our third party investment managers at a portfolio level. Where broker quotes are the primary source of the valuations, sufficient information regarding the specific inputs utilized by the brokers is generally not available to support a Level 2 classification. The Company obtains the majority of broker quoted values from third party investment managers who perform independent verifications of these valuations using pricing matrices based upon information gathered by market traders. In addition, for the majority of these securities, the Company compares the broker quotes to independent valuations obtained from third party pricing vendors, which may also consist of broker quotes, to assess if the prices received represent a reasonable estimate of the fair value. As discussed in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ," under the Life Retro Arrangements, all of the investment results associated with the Life Funds Withheld Assets ultimately accrue to GCLR. Because the Company no longer shares in the risks and rewards of the underlying performance of the Life Funds Withheld Assets, the financial statements and accompanying notes included herein separately report the Life Funds Withheld Assets from the rest of the Company's investments. For further information about the Company's fair value measurements, see Item 8, Note 2(b), "Significant Accounting Policies - Fair Value Measurements ," to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 . (a) Fair Value Summary The following tables set forth the Company’s assets and liabilities that were accounted for at fair value as of September 30, 2015 and December 31, 2014 by level within the fair value hierarchy: September 30, 2015 (U.S. dollars in thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Unobservable Inputs (Level 3) Collateral and Counterparty Netting Balance at Assets Fixed maturities - Available for Sale ("AFS") - Excluding Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ — $ 4,298,723 $ — $ — $ 4,298,723 Corporate - Financials — 3,062,530 10,000 — 3,072,530 Corporate - Non Financials (1) — 6,850,318 5,272 — 6,855,590 Residential mortgage-backed securities – Agency ("RMBS - Agency") — 3,920,607 2,882 — 3,923,489 Residential mortgage-backed securities – Non-Agency ("RMBS - Non-Agency") — 362,965 — — 362,965 Commercial mortgage-backed securities ("CMBS") — 850,084 — — 850,084 Collateralized debt obligations ("CDOs") — 2,500 407,663 — 410,163 Other asset-backed securities (1) — 2,059,478 36,120 — 2,095,598 U.S. States and political subdivisions of the States — 2,648,670 — — 2,648,670 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 5,120,149 — — 5,120,149 Total fixed maturities - AFS - Excluding Funds Withheld Assets, at fair value $ — $ 29,176,024 $ 461,937 $ — $ 29,637,961 Equity securities, at fair value 478,815 490,891 — — 969,706 Short-term investments, at fair value (1)(2) — 546,020 — — 546,020 Total investments AFS - Excluding Funds Withheld Assets $ 478,815 $ 30,212,935 $ 461,937 $ — $ 31,153,687 Fixed maturities - Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ — $ 13,412 $ — $ — $ 13,412 Corporate - Financials — 669,788 — — 669,788 Corporate - Non Financials — 1,480,112 — — 1,480,112 RMBS – Agency — 814 — — 814 RMBS – Non-Agency — 28,833 — — 28,833 CMBS — 141,166 — — 141,166 Other asset-backed securities — 162,871 — — 162,871 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 1,141,365 — — 1,141,365 Total fixed maturities - AFS - Life Funds Withheld Assets, at fair value $ — $ 3,638,361 $ — $ — $ 3,638,361 Total investments - AFS, at fair value $ 478,815 $ 33,851,296 $ 461,937 $ — $ 34,792,048 Fixed maturities - trading securities ("Trading") U.S. Government and Government-Related/Supported $ — $ 4,610 $ — $ — $ 4,610 Corporate - Financials — 219,767 — — 219,767 Corporate - Non Financials — 393,246 — — 393,246 CMBS — 4,982 — — 4,982 Other asset-backed securities — 19,872 — — 19,872 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 342,746 — — 342,746 Total fixed maturities - Trading, at fair value $ — $ 985,223 $ — $ — $ 985,223 Cash equivalents (3) 940,303 455,699 — — 1,396,002 Cash equivalents - Life Funds Withheld Assets (3) 1,440 86,840 — — 88,280 Other investments (4) — 1,051,558 278,222 — 1,329,780 Other assets (5) — 59,231 14,884 (3,900 ) 70,215 Total assets accounted for at fair value $ 1,420,558 $ 36,489,847 $ 755,043 $ (3,900 ) $ 38,661,548 Liabilities Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable) (6) $ — $ 468,187 $ — $ — $ 468,187 Financial instruments sold, but not yet purchased (7) 1,588 693 — — 2,281 Other liabilities (5) — 25,142 24,568 (3,900 ) 45,810 Total liabilities accounted for at fair value $ 1,588 $ 494,022 $ 24,568 $ (3,900 ) $ 516,278 December 31, 2014 (U.S. dollars in thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Unobservable Inputs (Level 3) Collateral and Counterparty Netting Balance at December 31, 2014 Assets Fixed maturities - AFS - Excluding Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ — $ 2,171,953 $ — $ — $ 2,171,953 Corporate - Financials — 2,761,916 — — $ 2,761,916 Corporate - Non Financials (1) — 6,010,563 5,894 — $ 6,016,457 Residential mortgage-backed securities – RMBS - Agency — 3,726,666 1,910 — $ 3,728,576 Residential mortgage-backed securities – RMBS - Non-Agency — 427,351 — — $ 427,351 CMBS — 1,052,544 — — $ 1,052,544 CDOs — 4,076 687,958 — $ 692,034 Other asset-backed securities (1) — 1,060,005 5,288 — $ 1,065,293 U.S. States and political subdivisions of the States — 2,021,272 — — $ 2,021,272 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 4,240,073 — — $ 4,240,073 Total fixed maturities - AFS - Excluding Funds Withheld Assets, at fair value $ — $ 23,476,419 $ 701,050 $ — $ 24,177,469 Equity securities, at fair value 502,284 366,008 — — 868,292 Short-term investments, at fair value (1)(2) — 256,727 — — 256,727 Total investments AFS - Excluding Funds Withheld Assets $ 502,284 $ 24,099,154 $ 701,050 $ — $ 25,302,488 Fixed maturities - Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ — $ 18,724 $ — $ — $ 18,724 Corporate - Financials — 801,019 — — $ 801,019 Corporate - Non Financials — 2,016,961 — — $ 2,016,961 RMBS – Agency — 3,782 — — $ 3,782 RMBS – Non-Agency — 85,335 — — $ 85,335 CMBS — 193,167 — — $ 193,167 Other asset-backed securities — 273,541 — — $ 273,541 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 1,789,036 — — $ 1,789,036 Total fixed maturities - AFS - Life Funds Withheld Assets, at fair value $ — $ 5,181,565 $ — $ — $ 5,181,565 Total investments - AFS, at fair value $ 502,284 $ 29,280,719 $ 701,050 $ — $ 30,484,053 Fixed maturities - Trading Corporate - Non Financials — 1,171 — — $ 1,171 Total fixed maturities - Trading, at fair value $ — $ 1,171 $ — $ — $ 1,171 Cash equivalents (3) 1,103,877 397,955 — — $ 1,501,832 Cash equivalents - Life Funds Withheld Assets (3) 460 132,738 — — $ 133,198 Other investments (4) — 708,974 185,083 — $ 894,057 Other assets (5) — 122,996 13,663 (696 ) $ 135,963 Total assets accounted for at fair value $ 1,606,621 $ 30,644,553 $ 899,796 $ (696 ) $ 33,150,274 Liabilities Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable) (6) $ — $ 450,831 $ — $ — $ 450,831 Financial instruments sold, but not yet purchased (7) 4,737 25,669 — — $ 30,406 Other liabilities (5) — 7,757 23,427 (696 ) $ 30,488 Total liabilities accounted for at fair value $ 4,737 $ 484,257 $ 23,427 $ (696 ) $ 511,725 ____________ (1) Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes had a fair value of $74.3 million and $79.9 million and an amortized cost of $64.6 million and $68.4 million as of September 30, 2015 and December 31, 2014 , respectively. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate values of these notes. (2) Short-term investments consist primarily of Corporate securities and U.S. and Non-U.S. Government and Government-Related/Supported securities. (3) Cash equivalents balances subject to fair value measurement include certificates of deposit and money market funds. Operating cash balances are not subject to recurring fair value measurement guidance. (4) The Other investments balance excludes certain structured transactions including certain investments in project finance transactions, and a payment obligation and liquidity financing provided to a structured credit vehicle as a part of a third party medium term note facility. These investments, which totaled $346.4 million as of September 30, 2015 and $354.4 million as of December 31, 2014 , are carried at amortized cost. For further information, see Item 8, Note 8, "Other Investments ," to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2014 . (5) Other assets and other liabilities include derivative instruments. The derivative balances included in each category are reported on a gross basis by level with a netting adjustment presented separately in the Collateral and Counterparty Netting column. The fair values of the individual derivative contracts are reported gross in their respective levels based on the fair value hierarchy. For further details regarding derivative fair values and associated collateral received or paid, see Note 7, "Derivative Instruments ," to the Unaudited Consolidated Financial Statements. (6) Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable) include balances related to the life retrocession embedded derivative, under which all investment results associated with the Life Funds Withheld Assets related to the Life Retro Arrangements described in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ," accrue to the benefit of GCLR. (7) Financial instruments sold, but not yet purchased, represent "short sales" and are included within "Payable for investments purchased" on the balance sheets. (b) Level 3 Assets and Liabilities The tables below present additional information about assets and liabilities measured at fair value on a recurring basis and for which Level 3 inputs were utilized to determine fair value. The tables present a reconciliation of the beginning and ending balances for the three and nine months ended September 30, 2015 and 2014 for all financial assets and liabilities measured at fair value using significant unobservable inputs (Level 3) at September 30, 2015 and 2014 , respectively. The tables do not include gains or losses that were reported in Level 3 in prior periods for assets that were transferred out of Level 3 prior to September 30, 2015 and 2014 , respectively. Gains and losses for assets and liabilities classified within Level 3 in the table below may include changes in fair value that are attributable to both observable inputs (Levels 1 and 2) and unobservable inputs (Level 3). Further, it should be noted that the following tables do not take into consideration the effect of offsetting Level 1 and 2 financial instruments entered into by the Company that are either economically hedged by certain exposures to the Level 3 positions or that hedge the exposures in Level 3 positions. In general, Level 3 assets include securities for which values were obtained from brokers where either significant inputs were utilized in determining the values that were difficult to corroborate with observable market data, or sufficient information regarding the specific inputs utilized by the broker was not available to support a Level 2 classification. Transfers into or out of Level 3 primarily arise as a result of the valuations utilized by the Company changing between either those provided by independent pricing services that do not contain significant unobservable inputs or other valuations sourced from brokers that are considered Level 3. There were no significant transfers between Level 1 and Level 2 during each of the three and nine months ended September 30, 2015 and 2014 . Level 3 Assets and Liabilities - Three Months Ended September 30, 2015 (U.S. dollars in thousands) Corporate - Financials Corporate - Non-Financials RMBS - Agency RMBS - Non Balance, beginning of period $ 10,000 $ 5,554 $ 3,038 $ — Realized gains (losses) — (45 ) — — Movement in unrealized gains (losses) — (1 ) (2 ) — Purchases and issuances (1) — — — — Sales — — — — Settlements — (236 ) (154 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ 10,000 $ 5,272 $ 2,882 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ (1 ) $ (2 ) $ — Level 3 Assets and Liabilities - Three Months Ended September 30, 2015 (U.S. dollars in thousands) CMBS CDO Other asset- Non-US Sovereign Balance, beginning of period $ — $ 484,171 $ 42,745 $ — Realized gains (losses) — (8,469 ) 553 — Movement in unrealized gains (losses) — 8,994 (976 ) — Purchases and issuances (1) — 2,101 3,334 — Sales — (56,576 ) — — Settlements — (22,558 ) (3,087 ) — Transfers into Level 3 — — — — Transfers out of Level 3 — — (6,449 ) — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 407,663 $ 36,120 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 164 $ (5 ) $ — Level 3 Assets and Liabilities - Three Months Ended September 30, 2015 (U.S. dollars in thousands) Short-term Other investments Derivative Contracts Balance, beginning of period $ — $ 255,672 $ (9,753 ) Realized gains (losses) — 9,185 — Movement in unrealized gains (losses) — (5,567 ) 69 Purchases and issuances (1) — 30,519 — Sales — (1,417 ) Settlements — (10,170 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — Fixed maturities to short-term investments classification change — — — Balance, end of period $ — $ 278,222 $ (9,684 ) Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 3,618 $ 69 ____________ (1) Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ." Level 3 Assets and Liabilities - Three Months Ended September 30, 2014 (U.S. dollars in thousands) Corporate - Financials Corporate - Non-Financials RMBS - Agency RMBS - Non Agency Balance, beginning of period $ — $ 3,933 $ 6,896 $ 11 Realized gains (losses) — 3 (1 ) — Movement in unrealized gains (losses) — 24 (7 ) (1 ) Purchases and issuances (1) — 2,316 120 — Sales — — — — Settlements — — (526 ) — Transfers into Level 3 — 766 — — Transfers out of Level 3 — — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 7,042 $ 6,482 $ 10 Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 27 $ (8 ) $ — Level 3 Assets and Liabilities - Three Months Ended September 30, 2014 (U.S. dollars in thousands) CMBS CDO Other asset- backed securities Non-US Sovereign Government, Provincial, Supranational and Government Related/Supported Balance, beginning of period $ 1,945 $ 732,824 $ 11,704 $ — Realized gains (losses) — 707 3 — Movement in unrealized gains (losses) — 1,591 (113 ) — Purchases and issuances (1) — 82,695 2,182 — Sales — (7,489 ) — — Settlements (569 ) (67,845 ) (1,726 ) — Transfers into Level 3 — — — — Transfers out of Level 3 (1,376 ) — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 742,483 $ 12,050 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 2,297 $ (110 ) $ — Level 3 Assets and Liabilities - Three Months Ended September 30, 2014 (U.S. dollars in thousands) Short-term investments Other investments Derivative Contracts - Net Balance, beginning of period $ — $ 124,475 $ (18,910 ) Realized gains (losses) — 1,850 — Movement in unrealized gains (losses) — 2,790 710 Purchases and issuances (1) — 22,308 — Sales — — — Settlements — (4,888 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — Fixed maturities to short-term investments classification change — — — Balance, end of period $ — $ 146,535 $ (18,200 ) Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 4,639 $ 710 ____________ (1) Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ." Level 3 Assets and Liabilities - Nine Months Ended September 30, 2015 (U.S. dollars in thousands) Corporate - Financials Corporate - Non-Financials RMBS - Agency RMBS - Non Balance, beginning of period $ — $ 5,894 $ 1,910 $ — Realized gains (losses) — (186 ) — — Movement in unrealized gains (losses) — 3 (4 ) — Purchases and issuances (1) 10,000 (123 ) 1,297 — Sales — — — — Settlements — (316 ) (321 ) — Transfers into Level 3 — — — — Transfers out of Level 3 — — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ 10,000 $ 5,272 $ 2,882 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ (137 ) $ (2 ) $ — Level 3 Assets and Liabilities - Nine Months Ended September 30, 2015 (U.S. dollars in thousands) CMBS CDO Other asset- Non-US Sovereign Balance, beginning of period $ — $ 687,958 $ 5,288 $ — Realized gains (losses) — (8,209 ) 644 — Movement in unrealized gains (losses) — 16,994 (966 ) — Purchases and issuances (1) — 14,042 43,962 — Sales — (211,661 ) — — Settlements — (91,461 ) (6,359 ) — Transfers into Level 3 — — — — Transfers out of Level 3 — — (6,449 ) — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 407,663 $ 36,120 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 4,889 $ 95 $ — Level 3 Assets and Liabilities - Nine Months Ended September 30, 2015 (U.S. dollars in thousands) Short-term Other investments Derivative Contracts Balance, beginning of period $ — $ 185,083 $ (9,764 ) Realized gains (losses) — 11,778 — Movement in unrealized gains (losses) — (7,533 ) 80 Purchases and issuances (1) — 103,822 — Sales — (1,417 ) — Settlements — (13,511 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — Fixed maturities to short-term investments classification change — — — Balance, end of period $ — $ 278,222 $ (9,684 ) Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 4,246 $ 80 ____________ (1) Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition " Level 3 Assets and Liabilities - Nine Months Ended September 30, 2014 (U.S. dollars in thousands) Corporate - Financials Corporate - Non-Financials RMBS - Agency RMBS - Non Agency Balance, beginning of period $ — $ 31,573 $ 10,473 $ 9 Realized gains (losses) — 158 5 — Movement in unrealized gains (losses) — (72 ) (20 ) 1 Purchases and issuances (1) — 3,759 120 — Sales — — — — Settlements — (5,513 ) (3,124 ) — Transfers into Level 3 — 766 — — Transfers out of Level 3 — (23,629 ) (972 ) — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 7,042 $ 6,482 $ 10 Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 117 $ (14 ) $ 2 Level 3 Assets and Liabilities - Nine Months Ended September 30, 2014 (U.S. dollars in thousands) CMBS CDO Other asset- backed securities Non-US Sovereign Government, Provincial, Supranational and Government Related/Supported Balance, beginning of period $ 12,533 $ 710,253 $ 11,877 $ — Realized gains (losses) 3 3,163 (17 ) — Movement in unrealized gains (losses) (3 ) 13,604 93 — Purchases and issuances (1) 1,376 185,710 5,182 — Sales — (48,313 ) — — Settlements (12,533 ) (121,934 ) (5,085 ) — Transfers into Level 3 — — — — Transfers out of Level 3 (1,376 ) — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 742,483 $ 12,050 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 15,513 $ 76 $ — Level 3 Assets and Liabilities - Nine Months Ended September 30, 2014 (U.S. dollars in thousands) Short-term investments Other investments Derivative Contracts - Net Balance, beginning of period $ 2,015 $ 113,472 $ (29,110 ) Realized gains (losses) — 10,541 — Movement in unrealized gains (losses) (15 ) 2,508 10,910 Purchases and issuances (1) — 43,394 — Sales — — — Settlements (2,000 ) (23,380 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — Fixed maturities to short-term investments classification change — — — Balance, end of period $ — $ 146,535 $ (18,200 ) Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 13,048 $ 10,910 ____________ (1) Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ". (c) Fixed maturities and short-term investments The Company’s Level 3 assets consist primarily of CDOs, for which non-binding broker quotes are the primary source of the valuations. Sufficient information regarding the specific inputs utilized by the brokers was not available to support a Level 2 classification. The Company obtains the majority of broker quotes for these CDOs from third party investment managers who perform independent verifications of these valuations using pricing matrices based upon information gathered by market traders. In addition, for the majority of these securities, the Company compares the broker quotes to independent valuations obtained from third party pricing vendors, which may also consist of broker quotes, to assess if the prices received represent a reasonable estimate of the fair value. Although the Company does not have access to the specific unobservable inputs that may have been used in the fair value measurements of the CDO securities provided by brokers, we would expect that the significant inputs considered are prepayment rates, probability of default, loss severity in the event of default, recovery rates, liquidity premium and reinvestment rates. Significant increases (decreases) in any of those inputs in isolation could result in a significantly different fair value measurement. Generally, a change in the assumption used for the probability of default is accompanied by a directionally similar change in the assumption used for the loss severity and a directionally opposite change in the assumption used for prepayment rates. The remainder of the Level 3 assets relate primarily to private investment funds and certain derivative positions as described below. (d) Other investments Included within the Other investments component of the Company’s Level 3 valuations are private investments and certain hedge fund investments where the Company is not deemed to have significant influence over the investee. The fair value of these investments is based upon net asset values received from the investment manager or general partner of the respective entity. The nature of the underlying investments held by the investee that form the basis of the net asset value include assets such as private business ventures and are such that significant Level 3 inputs are utilized in the determination of the individual underlying holding values and, accordingly, the fair value of the Company’s investment in each entity is classified within Level 3. The Company has not adjusted the net asset values received; however, management incorporates factors such as the most recent financial information received, annual audited financial statements and the values at which capital transactions with the investee take place when applying judgment regarding whether any adjustments should be made to the net asset value in recording the fair value of each position. For further details regarding the nature of Other investments and related features see Item 8, Note 8, "Other Investments ," to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 . (e) Derivative instruments Derivative instruments recorded within Other liabilities and classified within Level 3 include credit derivatives providing protection on senior tranches of structured finance transactions where the value is obtained directly from the investment bank counterparty and sufficient information regarding the inputs utilized in such valuation was not obtained to support a Level 2 classification and guaranteed minimum income benefits embedded within one reinsurance contract. The majority of inputs utilized in the valuations of these types of derivative contracts are considered Level 1 or Level 2; however, each valuation includes at least one Level 3 input that was significant to the valuation and, accordingly, the values are disclosed within Level 3. The calculation of the change in fair value of the embedded derivative associated with the Life Retro Arrangements includes interest income and realized and unrealized gains and losses on Life Funds Withheld Assets and certain related expenses related to the Life Funds Withheld Assets. The fair value of the embedded derivative is included in "Funds withheld on life retrocession arrangements, net of future policy benefit reserves recoverable," on the consolidated balance sheets. The fair value of the embedded derivative is considered a Level 2 valuation. (f) Financial Instruments Not Carried at Fair Value Authoritative guidance over disclosures about the fair value of financial instruments requires additional disclosure of fair value information for financial instruments not carried at fair value in both interim and annual reporting periods. Certain financial instruments, particularly insurance contracts, are excluded from these fair value disclosure requirements. The carrying values of cash and cash equivalents, accrued investment income, net receivable from investments sold, other assets, net payable for investments purchased, other liabilities and other financial instruments not included below approximated their fair values. The following table includes financial instruments for which the carrying value differs from the estimated fair values as of September 30, 2015 and December 31, 2014 . All of these fair value estimates are considered Level 2 fair value measurements. September 30, 2015 December 31, 2014 (U.S. dollars in thousands) Carrying Value Fair Value Carrying Value Fair Value Financial Assets - Other investments, structured transactions $ 346,359 $ 363,251 $ 354,382 $ 371,625 Deposit liabilities $ 1,194,815 $ 1,471,562 $ 1,245,367 $ 1,543,761 Notes payable and debt 2,726,917 2,919,907 1,662,580 1,897,854 Financial Liabilities $ 3,921,732 $ 4,391,469 $ 2,907,947 $ 3,441,615 The Company historically participated in structured transactions. Remaining structured transactions include cash loans supporting project finance transactions, a liquidity facility financing provided to structured project deals and an investment in a payment obligation with an insurance company. These transactions are carried at amortized cost. The fair value of these investments held by the Company is determined through use of internal models utilizing reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data. Deposit liabilities include obligations under structured insurance and reinsurance transactions. For purposes of fair value disclosures, the Company determined the estimated fair value of the deposit liabilities by assuming a discount rate equal to the appropriate U.S. Treasury rate plus 50.5 basis points and 29.5 basis points as of September 30, 2015 and December 31, 2014 , respectively. The discount rate incorporates the Company’s own credit risk into the determination of estimated fair value. The fair values of the Company’s notes payable and debt outstanding were determined based on quoted market prices. There are no significant concentrations of credit risk within the Company’s financial instruments as defined in the authoritative guidance over disclosures of fair value of financial instruments not carried at fair value, which excludes certain financial instruments, particularly insurance contracts.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information The Company is organized into two operating segments: Insurance and Reinsurance. Subsequent to the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ," the underwriting results of the acquired businesses from the Acquisition Date through September 30, 2015 are included in the Company's Insurance or Reinsurance segment, as appropriate. The Company’s general investment and financing operations are reflected in "Corporate and Other." Subsequent to the transaction described in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ," GCLR reinsures the majority of the Company's life reinsurance business through the Life Retro Arrangements. The results of the Run-Off Life Operations not subject to the Life Retro Arrangements are also reported within Corporate and Other. The Company evaluates the performance of both the Insurance and Reinsurance segments based on underwriting profit. Other items of revenues and expenditures of the Company are not evaluated at the segment level. In addition, the Company does not allocate investment assets used to support its Property and Casualty ("P&C") operations to the individual segments, except as noted below. Investment assets related to the Company’s Run-Off Life Operations and certain structured products included in the Insurance and Reinsurance segments are held in separately identified portfolios. As such, net investment income from these assets is included in the contribution from the applicable segment or in Corporate and Other. The following tables summarize the segment results for the three and nine months ended September 30, 2015 and 2014 : Three Months Ended September 30, 2015 (U.S. dollars in thousands, except ratios) Insurance Reinsurance Total P&C Corporate and Other (1) Total Gross premiums written $ 2,200,196 $ 458,946 $ 2,659,142 $ 80,208 $ 2,739,350 Net premiums written 1,664,562 408,654 2,073,216 17,812 2,091,028 Net premiums earned 1,632,988 772,752 2,405,740 17,812 2,423,552 Net losses and loss expenses (2) 1,037,727 426,558 1,464,285 22,579 1,486,864 Acquisition costs (2) 214,773 189,671 404,444 4,729 409,173 Operating expenses (3) 334,211 88,682 422,893 (26 ) 422,867 Underwriting profit (loss) $ 46,277 $ 67,841 $ 114,118 $ (9,470 ) $ 104,648 Net investment income - excluding Life Funds Withheld Assets (4) 152,738 10,254 162,992 Net investment income - Life Funds Withheld Assets 46,586 46,586 Net results from structured products (5) 3,328 1,109 4,437 — 4,437 Net fee income and other (6) (5,207 ) 533 (4,674 ) 254 (4,420 ) Net realized gains (losses) on investments - excluding Life Funds Withheld Assets (197 ) (4 ) (201 ) Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets — 51,608 51,608 Net realized and unrealized gains (losses) on derivative instruments — (7,903 ) (7,903 ) Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets — (126,140 ) (126,140 ) Net income (loss) from investment fund affiliates and operating affiliates (7) — 4,481 4,481 Exchange (gains) losses — 11,661 11,661 Corporate operating expenses — 135,500 135,500 Contribution from P&C and Corporate and Other 266,422 (177,495 ) 88,927 Interest expense (8) 40,798 40,798 Non-controlling interests 57,889 57,889 Income tax expense (37,042 ) (37,042 ) Net income (loss) attributable to ordinary shareholders $ 27,282 Ratios – P&C operations: (9) Loss and loss expense ratio 63.5 % 55.2 % 60.9 % Underwriting expense ratio 33.7 % 36.0 % 34.4 % Combined ratio 97.2 % 91.2 % 95.3 % ____________ (1) Corporate and Other includes other items of our revenues and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations. (2) The Company has reflected the amortization of certain fair value adjustments recorded in conjunction with the Catlin Acquisition within the respective segments. (3) Operating expenses of the segments exclude Corporate operating expenses, shown separately. (4) Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products. (5) The net results from P&C structured products include net investment income and interest expense of $15.6 million and $11.1 million , respectively. (6) Net fee income and other includes operating expenses from the Company's loss prevention consulting services business. (7) The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one -month and three -month lag, respectively. (8) Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments. (9) Ratios are based on net premiums earned from P&C operations. Three Months Ended September 30, 2014 (U.S. dollars in thousands, except ratios) Insurance Reinsurance Total P&C Corporate and Other (1) Total Gross premiums written $ 1,324,418 $ 276,284 $ 1,600,702 $ 83,496 $ 1,684,198 Net premiums written 956,185 258,061 1,214,246 19,739 1,233,985 Net premiums earned 1,018,416 435,257 1,453,673 19,739 1,473,412 Net losses and loss expenses 650,256 209,332 859,588 20,101 879,689 Acquisition costs 95,992 84,800 180,792 2,090 182,882 Operating expenses (2) 218,281 50,637 268,918 2,785 271,703 Underwriting profit (loss) $ 53,887 $ 90,488 $ 144,375 $ (5,237 ) $ 139,138 Net investment income - excluding Life Funds Withheld Assets (3) 141,575 11,552 153,127 Net investment income - Life Funds Withheld Assets 56,474 56,474 Net results from structured products (4) 3,571 1,720 5,291 — 5,291 Net fee income and other (5) (3,826 ) 601 (3,225 ) 167 (3,058 ) Net realized gains (losses) on investments - excluding Life Funds Withheld Assets 9,418 395 9,813 Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets — (5,472 ) (5,472 ) Net realized and unrealized gains (losses) on derivative instruments — 5,131 5,131 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets — (201,264 ) (201,264 ) Net income (loss) from investment fund affiliates and operating affiliates (6) — 44,521 44,521 Exchange (gains) losses — (23,348 ) (23,348 ) Corporate operating expenses — 55,322 55,322 Contribution from P&C and Corporate and Other 297,434 (125,707 ) 171,727 Interest expense (7) 31,703 31,703 Non-controlling interests 37,583 37,583 Income tax expense 30,057 30,057 Net income (loss) attributable to ordinary shareholders $ 72,384 Ratios – P&C operations: (8) Loss and loss expense ratio 63.8 % 48.1 % 59.1 % Underwriting expense ratio 30.9 % 31.1 % 31.0 % Combined ratio 94.7 % 79.2 % 90.1 % ____________ (1) Corporate and Other includes other items of our revenue and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations. (2) Operating expenses of the segments exclude Corporate operating expenses, shown separately. (3) Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products. (4) The net results from P&C structured products include net investment income and interest credit of $16.8 million and $11.1 million , respectively. (5) Net fee income and other includes operating expenses from the Company's loss prevention consulting services business. (6) The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one -month and three -month lag, respectively. (7) Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments. (8) Ratios are based on net premiums earned from P&C operations. Nine Months Ended September 30, 2015 (U.S. dollars in thousands, except ratios) Insurance Reinsurance Total P&C Corporate and Other (1) Total Gross premiums written $ 6,074,387 $ 2,066,856 $ 8,141,243 $ 234,602 $ 8,375,845 Net premiums written 4,155,442 1,854,590 6,010,032 50,576 6,060,608 Net premiums earned 4,008,200 1,780,829 5,789,029 50,576 5,839,605 Net losses and loss expenses (2) 2,551,044 834,263 3,385,307 64,047 3,449,354 Acquisition costs (2) 476,876 419,380 896,256 8,230 904,486 Operating expenses (3) 834,829 202,904 1,037,733 846 1,038,579 Underwriting profit (loss) $ 145,451 $ 324,282 $ 469,733 $ (22,547 ) $ 447,186 Net investment income - excluding Life Funds Withheld Assets (4) 435,007 31,295 466,302 Net investment income - Life Funds Withheld Assets 143,869 143,869 Net results from structured products (5) 9,634 5,085 14,719 — 14,719 Net fee income and other (6) (14,705 ) 1,981 (12,724 ) 432 (12,292 ) Net realized gains (losses) on investments - excluding Life Funds Withheld Assets 9,833 (1,081 ) 8,752 Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets — 145,513 145,513 Net realized and unrealized gains (losses) on derivative instruments — 57,127 57,127 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets — (116,333 ) (116,333 ) Net income (loss) from investment fund affiliates and operating affiliates (7) — 103,317 103,317 Gain on sale of operating affiliate 340,407 340,407 Exchange (gains) losses — 49,425 49,425 Corporate operating expenses — 328,930 328,930 Contribution from P&C and Corporate and Other 916,568 303,644 1,220,212 Interest expense (8) 121,317 121,317 Non-controlling interests 100,158 100,158 Income tax expense 20,135 20,135 Net income (loss) attributable to ordinary shareholders $ 978,602 Ratios – P&C operations: (9) Loss and loss expense ratio 63.6 % 46.8 % 58.5 % Underwriting expense ratio 32.8 % 35.0 % 33.4 % Combined ratio 96.4 % 81.8 % 91.9 % ____________ (1) Corporate and Other includes other items of our revenue and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations. (2) The Company has reflected the amortization of certain fair value adjustments recorded in conjunction with the Catlin Acquisition within the respective segments. (3) Operating expenses of the segments exclude Corporate operating expenses, shown separately. (4) Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products. (5) The net results from P&C structured products include net investment income and interest expense of $46.7 million and $31.7 million , respectively. (6) Net fee income and other includes operating expenses from the Company's loss prevention consulting services business. (7) The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one -month and three -month lag, respectively. (8) Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments. (9) Ratios are based on net premiums earned from P&C operations. Nine Months Ended September 30, 2014 (U.S. dollars in thousands, except ratios) Insurance Reinsurance Total P&C Corporate Total Gross premiums written $ 4,513,749 $ 1,627,121 $ 6,140,870 $ 254,503 $ 6,395,373 Net premiums written 3,080,432 1,486,680 4,567,112 154,568 4,721,680 Net premiums earned 3,014,846 1,289,431 4,304,277 154,568 4,458,845 Net losses and loss expenses 1,917,076 601,897 2,518,973 218,987 2,737,960 Acquisition costs 300,855 252,909 553,764 13,151 566,915 Operating expenses (2) 635,264 139,080 774,344 8,182 782,526 Underwriting profit (loss) $ 161,651 $ 295,545 $ 457,196 $ (85,752 ) $ 371,444 Net investment income - excluding Life Funds Withheld Assets (3) 429,657 134,562 564,219 Net investment income - Life Funds Withheld Assets 75,639 75,639 Net results from structured products (4) 40,106 8,023 48,129 — 48,129 Net fee income and other (5) (8,605 ) 1,938 (6,667 ) 257 (6,410 ) Loss on sale of life reinsurance subsidiary — 666,423 666,423 Net realized gains (losses) on investments - excluding Life Funds Withheld Assets 105,589 4,297 109,886 Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets — (13,619 ) (13,619 ) Net realized and unrealized gains (losses) on derivative instruments — 18,540 18,540 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets — (218,810 ) (218,810 ) Net income (loss) from investment fund affiliates and operating affiliates (6) — 169,530 169,530 Exchange (gains) losses — 8,234 8,234 Corporate operating expenses — 163,155 163,155 Contribution from P&C and Corporate and Other 1,033,904 (753,168 ) 280,736 Interest expense (7) 96,147 96,147 Non-controlling interests 77,024 77,024 Income tax expense 58,724 58,724 Net income (loss) attributable to ordinary shareholders $ 48,841 Ratios – P&C operations: (8) Loss and loss expense ratio 63.6 % 46.7 % 58.5 % Underwriting expense ratio 31.0 % 30.4 % 30.9 % Combined ratio 94.6 % 77.1 % 89.4 % ____________ (1) Corporate and Other includes other items of our revenue and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations. (2) Operating expenses of the segments exclude Corporate operating expenses, shown separately. (3) Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products. (4) The net results from P&C structured products include net investment income and interest credit of $52.5 million and $3.7 million , respectively. (5) Net fee income and other includes operating expenses from the Company's loss prevention consulting services business. (6) The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one -month and three -month lag, respectively. (7) Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments. (8) Ratios are based on net premiums earned from P&C operations. The following tables summarize the Company’s net premiums earned by line of business for the three and nine months ended September 30, 2015 and 2014 : Three Months Ended September 30, 2015 (U.S. dollars in thousands) Insurance Reinsurance Corporate Total P&C Operations: Professional $ 299,639 $ 46,877 $ — $ 346,516 Casualty 473,777 141,135 — 614,912 Property catastrophe — 205,337 — 205,337 Property 320,878 271,297 — 592,175 Marine, energy, aviation and satellite — 36,345 — 36,345 Specialty 462,029 — — 462,029 Other (1) 76,665 71,761 — 148,426 Total P&C Operations $ 1,632,988 $ 772,752 $ — $ 2,405,740 Corporate and Other: Run-off Life operations - Annuity $ — $ — $ — $ — Run-off Life operations - Other Life — — 17,812 17,812 Total Corporate and Other $ — $ — $ 17,812 $ 17,812 Total $ 1,632,988 $ 772,752 $ 17,812 $ 2,423,552 Three Months Ended September 30, 2014 (U.S. dollars in thousands) Insurance Reinsurance Corporate and Other Total P&C Operations: Professional $ 269,275 $ 45,221 $ — $ 314,496 Casualty 358,505 66,638 — 425,143 Property catastrophe — 103,813 — 103,813 Property 139,663 155,415 — 295,078 Marine, energy, aviation and satellite — 30,511 — 30,511 Specialty 186,360 — — 186,360 Other (1) 64,613 33,659 — 98,272 Total P&C Operations $ 1,018,416 $ 435,257 $ — $ 1,453,673 Corporate and Other: Run-off Life operations - Annuity $ — $ — $ 2 $ 2 Run-off Life operations - Other Life — — 19,737 19,737 Total Corporate and Other $ — $ — $ 19,739 $ 19,739 Total $ 1,018,416 $ 435,257 $ 19,739 $ 1,473,412 ____________ (1) Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines. Nine Months Ended September 30, 2015 (U.S. dollars in thousands) Insurance Reinsurance Corporate Total P&C Operations: Professional $ 852,398 $ 125,110 $ — $ 977,508 Casualty 1,203,584 325,130 — 1,528,714 Property catastrophe — 462,862 — 462,862 Property 708,275 634,419 — 1,342,694 Marine, energy, aviation and satellite — 86,969 — 86,969 Specialty 1,014,147 — — 1,014,147 Other (1) 229,796 146,339 — 376,135 Total P&C Operations $ 4,008,200 $ 1,780,829 $ — $ 5,789,029 Corporate and Other: Run-off Life operations - Annuity $ — $ — $ — $ — Run-off Life operations - Other Life — — 50,576 50,576 Total Corporate and Other $ — $ — $ 50,576 $ 50,576 Total $ 4,008,200 $ 1,780,829 $ 50,576 $ 5,839,605 Nine Months Ended September 30, 2014 (U.S. dollars in thousands) Insurance Reinsurance Corporate Total P&C Operations: Professional $ 812,211 $ 139,564 $ — $ 951,775 Casualty 1,061,499 226,288 — 1,287,787 Property catastrophe — 324,812 — 324,812 Property 422,270 432,991 — 855,261 Marine, energy, aviation and satellite — 75,090 — 75,090 Specialty 543,217 — — 543,217 Other (1) 175,649 90,686 — 266,335 Total P&C Operations $ 3,014,846 $ 1,289,431 $ — $ 4,304,277 Corporate and Other: Run-off Life operations - Annuity $ — $ — $ 53,363 $ 53,363 Run-off Life operations - Other Life — — 101,205 101,205 Total Corporate and Other $ — $ — $ 154,568 $ 154,568 Total $ 3,014,846 $ 1,289,431 $ 154,568 $ 4,458,845 ____________ (1) Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines.

Investments

Investments	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Investments	Investments (a) Fixed Maturities, Short-Term Investments and Equity Securities Classification of Fixed Income Securities During the second quarter of 2014, fixed maturities with a carrying value of $2.8 billion were reclassified from held to maturity ("HTM") to AFS in conjunction with the sale of XLLR, discussed in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ." As a result, the Company no longer holds HTM securities. Gross unrealized gains and gross unrealized losses, net of tax, of $424.9 million and nil , respectively, related to these securities were recognized in other comprehensive income on the date of transfer. For certain annuity contracts that are subject to the Life Retro Arrangements, policy benefit reserves were historically increased for the impact of changes in unrealized gains on investments supporting such contracts as if the gains had been realized, with a corresponding entry to other comprehensive income ("Shadow Adjustments"). In conjunction with the sale of XLLR and the related reclassification of securities from HTM to AFS, the Company recorded an additional gross charge of $440.5 million , net of tax, as a reduction of comprehensive income for such Shadow Adjustments on the date of the transfer. See Note 15, "Accumulated Other Comprehensive Income (Loss) ," for further information. All of the reclassified securities are included within the Life Funds Withheld Assets, along with certain other available for sale securities as defined in the sale and purchase agreement relating to the sale of XLLR. The Life Funds Withheld Assets are managed pursuant to agreed investment guidelines that meet the contractual commitments of the XL ceding companies and applicable laws and regulations. All of the investment results associated with the Life Funds Withheld Assets ultimately accrue to GCLR. Because the Company no longer shares in the risks and rewards of the underlying performance of the Life Funds Withheld Assets, disclosures within the financial statements and accompanying notes included herein separate the Life Funds Withheld Assets from the rest of the Company's investments. Amortized Cost and Fair Value Summary The cost (amortized cost for fixed maturities and short-term investments), fair value, gross unrealized gains and gross unrealized (losses), including non-credit related OTTI recorded in accumulated other comprehensive income ("AOCI"), of the Company’s AFS investments as of September 30, 2015 and December 31, 2014 , were as follows: September 30, 2015 (U.S. dollars in thousands) Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Non-credit Related OTTI (1) Fixed maturities - AFS - Excluding Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ 4,241,444 $ 72,193 $ (14,914 ) $ 4,298,723 $ — Corporate - Financials 3,029,683 60,655 (17,808 ) 3,072,530 — Corporate - Non Financials (2) 6,735,784 191,026 (71,220 ) 6,855,590 (3,309 ) RMBS – Agency 3,831,823 100,257 (8,591 ) 3,923,489 — RMBS – Non-Agency 351,793 27,528 (16,356 ) 362,965 (55,474 ) CMBS 837,416 17,642 (4,974 ) 850,084 (1,210 ) CDOs 419,019 1,486 (10,342 ) 410,163 (1,460 ) Other asset-backed securities (2) 2,072,017 34,317 (10,736 ) 2,095,598 (1,351 ) U.S. States and political subdivisions of the States 2,536,974 118,345 (6,649 ) 2,648,670 — Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 5,088,447 113,073 (81,371 ) 5,120,149 — Total fixed maturities - AFS - Excluding Life Funds Withheld Assets $ 29,144,400 $ 736,522 $ (242,961 ) $ 29,637,961 $ (62,804 ) Total short-term investments - Excluding Life Funds Withheld Assets $ 545,979 $ 1,589 $ (1,548 ) $ 546,020 $ — Total equity securities - Excluding Life Funds Withheld Assets $ 984,192 $ 66,786 $ (81,272 ) $ 969,706 $ — Total investments - AFS - Excluding Life Funds Withheld Assets $ 30,674,571 $ 804,897 $ (325,781 ) $ 31,153,687 $ (62,804 ) Fixed maturities - AFS - Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ 10,998 $ 2,414 $ — $ 13,412 $ — Corporate - Financials 596,259 73,529 — 669,788 — Corporate - Non Financials 1,273,946 206,166 — 1,480,112 — RMBS – Agency 652 162 — 814 — RMBS – Non-Agency 25,341 3,492 — 28,833 — CMBS 121,266 19,900 — 141,166 — Other asset-backed securities 141,774 21,097 — 162,871 — Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 892,383 248,982 — 1,141,365 — Total fixed maturities - AFS - Life Funds Withheld Assets $ 3,062,619 $ 575,742 $ — $ 3,638,361 $ — Total investments - AFS $ 33,737,190 $ 1,380,639 $ (325,781 ) $ 34,792,048 $ (62,804 ) Fixed maturities - Trading - Life Funds Withheld Assets Amortized Cost Fair Value U.S. Government and Government-Related/Supported $ 4,614 $ 4,610 Corporate - Financials 228,026 219,767 Corporate - Non Financials 409,745 393,246 CMBS 5,002 4,982 Other asset-backed securities 20,119 19,872 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 337,249 342,746 Total investments - Trading - Life Funds Withheld Assets $ 1,004,755 $ 985,223 ___________ (1) Represents the non-credit component of OTTI losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the date an impairment was recorded. (2) Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $74.3 million and an amortized cost of $64.6 million . These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes. December 31, 2014 (U.S. dollars in thousands) Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Non-credit Related OTTI (1) Fixed maturities - AFS - Excluding Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ 2,100,851 $ 77,889 $ (6,787 ) $ 2,171,953 $ — Corporate - Financials 2,687,797 87,058 (12,939 ) 2,761,916 — Corporate - Non Financials (2) 5,774,333 278,747 (36,623 ) 6,016,457 (3,309 ) RMBS – Agency 3,625,171 114,188 (10,783 ) 3,728,576 — RMBS – Non-Agency 404,398 41,108 (18,155 ) 427,351 (67,918 ) CMBS 1,033,819 23,987 (5,262 ) 1,052,544 (2,033 ) CDOs 717,544 1,659 (27,169 ) 692,034 (1,663 ) Other asset-backed securities (2) 1,028,528 42,810 (6,045 ) 1,065,293 (1,797 ) U.S. States and political subdivisions of the States 1,892,566 129,910 (1,204 ) 2,021,272 — Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 4,162,425 139,484 (61,836 ) 4,240,073 — Total fixed maturities - AFS - Excluding Life Funds Withheld Assets $ 23,427,432 $ 936,840 $ (186,803 ) $ 24,177,469 $ (76,720 ) Total short-term investments - Excluding Life Funds Withheld Assets $ 257,221 $ 49 $ (543 ) $ 256,727 $ — Total equity securities - Excluding Life Funds Withheld Assets $ 763,833 $ 130,689 $ (26,230 ) $ 868,292 $ — Total investments - AFS - Excluding Life Funds Withheld Assets $ 24,448,486 $ 1,067,578 $ (213,576 ) $ 25,302,488 $ (76,720 ) Fixed maturities - AFS - Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ 14,866 $ 3,858 $ — $ 18,724 $ — Corporate - Financials 701,587 99,432 — 801,019 — Corporate - Non Financials 1,706,262 310,699 — 2,016,961 — RMBS – Agency 3,301 481 — 3,782 — RMBS – Non-Agency 71,075 14,260 — 85,335 — CMBS 168,886 24,281 — 193,167 — Other asset-backed securities 238,168 35,373 — 273,541 — Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 1,397,194 391,842 — 1,789,036 — Total fixed maturities - AFS - Life Funds Withheld Assets $ 4,301,339 $ 880,226 $ — $ 5,181,565 $ — Total investments - AFS $ 28,749,825 $ 1,947,804 $ (213,576 ) $ 30,484,053 $ (76,720 ) Fixed maturities - Trading - Life Funds Withheld Assets Amortized Cost Fair Value Corporate - Non Financials $ 1,180 $ 1,171 Total investments - Trading - Life Funds Withheld Assets $ 1,180 $ 1,171 ____________ (1) Represents the non-credit component of OTTI losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the date an impairment was recorded. (2) Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $79.9 million and an amortized cost of $68.4 million . These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes. As of September 30, 2015 and December 31, 2014 , approximately 2.1% and 3.0% , respectively, of the Company's fixed income investment portfolio at fair value, excluding Life Funds Withheld Assets, was invested in securities that were below investment grade or not rated. Approximately 15.9% and 24.9% of the gross unrealized losses in the Company's fixed income investment portfolio, excluding Life Funds Withheld Assets, as of September 30, 2015 and December 31, 2014 , respectively, related to securities that were below investment grade or not rated. Contractual Maturities Summary The contractual maturities of AFS fixed income securities at September 30, 2015 and December 31, 2014 are shown below. Actual 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, 2015 December 31, 2014 (U.S. dollars in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Fixed maturities - AFS - Excluding Life Funds Withheld Assets Due less than one year $ 2,235,684 $ 2,240,138 $ 1,972,224 $ 1,980,429 Due after 1 through 5 years 12,528,098 12,699,855 8,919,037 9,113,651 Due after 5 through 10 years 5,429,115 5,518,600 4,232,396 4,412,569 Due after 10 years 1,439,435 1,537,069 1,494,315 1,705,022 $ 21,632,332 $ 21,995,662 $ 16,617,972 $ 17,211,671 RMBS – Agency 3,831,823 3,923,489 3,625,171 3,728,576 RMBS – Non-Agency 351,793 362,965 404,398 427,351 CMBS 837,416 850,084 1,033,819 1,052,544 CDOs 419,019 410,163 717,544 692,034 Other asset-backed securities 2,072,017 2,095,598 1,028,528 1,065,293 Total mortgage and asset-backed securities $ 7,512,068 $ 7,642,299 $ 6,809,460 $ 6,965,798 Total fixed maturities - AFS - Excluding Life Funds Withheld Assets $ 29,144,400 $ 29,637,961 $ 23,427,432 $ 24,177,469 Fixed maturities - AFS - Life Funds Withheld Assets Due less than one year $ 93,671 $ 104,481 $ 117,048 $ 125,326 Due after 1 through 5 years 441,114 472,560 638,526 685,787 Due after 5 through 10 years 585,388 671,738 1,004,698 1,165,348 Due after 10 years 1,653,413 2,055,898 2,059,637 2,649,279 $ 2,773,586 $ 3,304,677 $ 3,819,909 $ 4,625,740 RMBS – Agency 652 814 3,301 3,782 RMBS – Non-Agency 25,341 28,833 71,075 85,335 CMBS 121,266 141,166 168,886 193,167 Other asset-backed securities 141,774 162,871 238,168 273,541 Total mortgage and asset-backed securities $ 289,033 $ 333,684 $ 481,430 $ 555,825 Total fixed maturities - AFS - Life Funds Withheld Assets $ 3,062,619 $ 3,638,361 $ 4,301,339 $ 5,181,565 Total fixed maturities - AFS $ 32,207,019 $ 33,276,322 $ 27,728,771 $ 29,359,034 Fixed maturities - Trading - Life Funds Withheld Assets Due less than one year $ 71,135 $ 71,139 $ — $ — Due after 1 through 5 years 239,984 233,244 — — Due after 5 through 10 years 178,020 176,077 1,180 1,171 Due after 10 years 490,495 479,909 — — $ 979,634 $ 960,369 $ 1,180 $ 1,171 CMBS 5,002 4,982 — — Other asset-backed securities 20,119 19,872 — — Total mortgage and asset-backed securities $ 25,121 $ 24,854 $ — $ — Total fixed maturities - Trading - Life Funds Withheld Assets $ 1,004,755 $ 985,223 $ 1,180 $ 1,171 OTTI Considerations Under final authoritative accounting guidance, a debt security for which amortized cost exceeds fair value is deemed to be other-than-temporarily impaired if it meets either of the following conditions: (a) the Company intends to sell, or it is more likely than not that the Company will be required to sell, the security before a recovery in value, or (b) the Company does not expect to recover the entire amortized cost basis of the security. Other than in a situation in which the Company has the intent to sell a debt security or more likely than not will be required to sell a debt security, the amount of the OTTI related to a credit loss on the security is recognized in earnings, and the amount of the OTTI related to other factors (e.g., interest rates, market conditions, etc.) is recorded as a component of OCI. The net amount recognized in earnings ("credit loss impairment") represents the difference between the amortized cost of the security and the net present value of its projected future cash flows discounted at the effective interest rate implicit in the debt security prior to impairment ("NPV"). The remaining difference between the security's NPV and its fair value is recognized in OCI. Subsequent changes in the fair value of these securities are included in OCI unless a further impairment is deemed to have occurred. In the scenario where the Company has the intent to sell a security in which its amortized cost exceeds its fair value, or it is more likely than not that it will be required to sell such a security, the entire difference between the security's amortized cost and its fair value is recognized in earnings. The determination of credit loss impairment is based on detailed analyses of underlying cash flows and other considerations. Such analyses require the use of certain assumptions to develop the estimated performance of underlying collateral. Key assumptions used include, but are not limited to, items such as RMBS default rates based on collateral duration in arrears, severity of losses on default by collateral class, collateral reinvestment rates and expected future general corporate default rates. Factors considered for all securities on a quarterly basis in determining that a gross unrealized loss is not other-than-temporarily impaired include management's consideration of current and near term liquidity needs and other available sources of funds, an evaluation of the factors and time necessary for recovery and an assessment of whether the Company has the intention to sell or considers it more likely than not that it will be forced to sell a security. Pledged Assets Certain of the Company's invested assets are held in trust and pledged in support of insurance and reinsurance liabilities as well as credit facilities. Such pledges are largely required by the Company's operating subsidiaries that are "non-admitted" under U.S. state insurance regulations, in order for the U.S. cedant to receive statutory credit for reinsurance. Also included are Life Funds Withheld Assets as noted in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ." Additionally, certain deposit liabilities and annuity contracts require the use of pledged assets. As of September 30, 2015 and December 31, 2014 , the Company had $18.8 billion and $15.2 billion in pledged assets, respectively. (b) Gross Unrealized Losses The following is an analysis of how long the AFS securities as of September 30, 2015 and December 31, 2014 had been in a continual unrealized loss position: Less than 12 months Equal to or greater than 12 months September 30, 2015 (U.S. dollars in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturities and short-term investments - AFS U.S. Government and Government-Related/Supported $ 1,257,855 $ (10,402 ) $ 89,971 $ (4,524 ) Corporate – Financials 862,043 (10,486 ) 83,008 (7,327 ) Corporate – Non Financials 2,181,253 (51,087 ) 218,856 (21,219 ) RMBS – Agency 590,089 (3,386 ) 237,798 (5,205 ) RMBS – Non-Agency 28,054 (1,022 ) 206,549 (15,334 ) CMBS 250,635 (2,361 ) 87,257 (2,613 ) CDOs 118,002 (286 ) 194,633 (10,056 ) Other asset-backed securities 639,048 (4,403 ) 57,445 (6,342 ) U.S. States and political subdivisions of the States 444,195 (5,520 ) 17,840 (1,131 ) Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 1,379,798 (47,122 ) 454,537 (34,683 ) Total fixed maturities and short-term investments - AFS $ 7,750,972 $ (136,075 ) $ 1,647,894 $ (108,434 ) Total equity securities $ 524,692 $ (81,272 ) $ — $ — Less than 12 months Equal to or greater than 12 months December 31, 2014 (U.S. dollars in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturities and short-term investments - AFS U.S. Government and Government-Related/Supported $ 251,091 $ (1,196 ) $ 342,890 $ (5,603 ) Corporate – Financials 387,619 (5,858 ) 105,155 (7,097 ) Corporate – Non Financials 949,851 (28,023 ) 319,066 (8,657 ) RMBS – Agency 134,535 (220 ) 512,652 (10,563 ) RMBS – Non-Agency 45,378 (1,358 ) 202,700 (16,797 ) CMBS 78,356 (385 ) 169,065 (4,877 ) CDOs 249,803 (2,666 ) 414,516 (24,503 ) Other asset-backed securities 143,044 (2,813 ) 57,544 (3,232 ) U.S. States and political subdivisions of the States 32,187 (210 ) 63,695 (994 ) Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 624,346 (19,043 ) 558,422 (43,251 ) Total fixed maturities and short-term investments - AFS $ 2,896,210 $ (61,772 ) $ 2,745,705 $ (125,574 ) Total equity securities $ 191,193 $ (26,230 ) $ — $ — The Company had gross unrealized losses totaling $325.8 million on 2,644 securities out of a total of 8,804 held as of September 30, 2015 in its AFS - Excluding Life Funds Withheld Assets portfolio, which either it considers to be temporarily impaired or with respect to which it reflects non-credit losses on other-than-temporarily impaired assets. Individual security positions comprising this balance have been evaluated by management to determine the severity of these impairments and whether they should be considered other-than-temporary. Management believes it is more likely than not that the issuer will be able to fund sufficient principal and interest payments to support the current amortized cost. Management, in its assessment of whether securities in a gross unrealized loss position are temporarily impaired, as described above, considers the significance of the impairments. As of September 30, 2015 , the AFS - Excluding Life Funds Withheld Assets portfolio included structured credit securities with gross unrealized losses of $0.2 million , which had a fair value of $0.03 million , and a cumulative fair value decline of greater than 50% of amortized cost. All of these securities are mortgage and asset-backed securities. (c) Net Realized Gains (Losses) The following represents an analysis of net realized gains (losses) on investments: Net Realized Gains (Losses) on Investments Three months ended September 30, Nine months ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Net realized gains (losses) on investments - excluding Life Funds Withheld Assets: Gross realized gains $ 88,224 $ 37,875 $ 199,070 $ 208,035 Gross realized losses on investments sold (45,711 ) (26,918 ) (120,440 ) (68,662 ) OTTI on investments, net of amounts transferred to other comprehensive income (42,714 ) (1,144 ) (69,878 ) (29,487 ) $ (201 ) $ 9,813 $ 8,752 $ 109,886 Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets: Gross realized gains $ 60,643 $ 4,511 $ 198,412 $ 5,135 Gross realized losses on investments sold (6,863 ) (2,489 ) (23,857 ) (2,489 ) OTTI on investments, net of amounts transferred to other comprehensive income (2,023 ) (7,494 ) (10,110 ) (16,265 ) Net unrealized gains (losses) on trading securities $ (149 ) $ — $ (18,932 ) $ — $ 51,608 $ (5,472 ) $ 145,513 $ (13,619 ) Total net realized gains (losses) on investments $ 51,407 $ 4,341 $ 154,265 $ 96,267 The significant components of the net impairment charges of $42.7 million for investments excluding Life Funds Withheld Assets for the three months ended September 30, 2015 were: ▪ $8.0 million for structured securities, principally CDOs that we no longer intend to hold for a period sufficient to recover their fair value to amortized cost. • $4.4 million related to certain equities that were in a loss position for more than 11 months. • $3.3 million related to certain equities that were in a loss position greater than 50% of their amortized cost. • $3.2 million related to certain high yield securities that we no longer intend to hold for a period sufficient to recover their fair value to amortized cost. • $2.2 million related to certain Other Investments that we no longer intend to hold for a period sufficient to recover their fair value to amortized cost. • $2.0 million related to certain quasi-government securities that we no longer intend to hold for a period sufficient to recover their fair value to amortized cost. • $19.6 million related to foreign exchange losses. The following table sets forth the amount of credit loss impairments on fixed income securities for which a portion of the OTTI loss was recognized in OCI, held by the Company as of the dates or for the periods indicated and the corresponding changes in such amounts. Credit Loss Impairments Three months ended September 30, Nine months ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Opening balance as of beginning of indicated period $ 94,219 $ 165,876 $ 131,942 $ 174,805 Credit loss impairment recognized in the current period on securities not previously impaired 2,004 93 9,565 134 Credit loss impairments previously recognized on securities that matured, paid down, prepaid or were sold during the period (1,531 ) (1,840 ) (38,564 ) (10,042 ) Credit loss impairments previously recognized on securities impaired to fair value during the period — — (2,629 ) — Additional credit loss impairments recognized in the current period on securities previously impaired 945 729 1,331 3,882 Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected (2,165 ) (2,471 ) (8,173 ) (6,392 ) Balance as of September 30, $ 93,472 $ 162,387 $ 93,472 $ 162,387 During the three months ended September 30, 2015 and 2014 , the $1.5 million and $1.8 million , respectively, of credit loss impairments previously recognized on securities that matured, or were paid down, prepaid or sold, included $1.3 million and $0.9 million , respectively, of non-Agency RMBS. During the nine months ended September 30, 2015 and 2014 , the $38.6 million and $10.0 million , respectively, credit loss impairments previously recognized on securities that matured, or were paid down, prepaid or sold, included $30.2 million and $6.1 million , respectively, of non-Agency RMBS.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments The Company enters into derivative instruments for both risk management and efficient portfolio management. The Company is exposed to potential loss from various market risks, and manages its market risks based on guidelines established by management and the Risk and Finance Committee of the Company's Board of Directors. The Company recognizes all derivatives as either assets or liabilities on the balance sheets and measures those instruments at fair value, with the changes in fair value of derivatives shown in the consolidated statement of income as "Net realized and unrealized gains (losses) on derivative instruments" unless the derivatives are designated as hedging instruments. The accounting for derivatives that are designated as hedging instruments is described in Item 8, Note 2(h), "Significant Accounting Policies - Derivative Instruments ," to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2014 . The following table summarizes information on the location and gross amounts of derivative fair values contained in the consolidated balance sheets as of September 30, 2015 and December 31, 2014 : September 30, 2015 December 31, 2014 (U.S. dollars in thousands) Asset Derivative Notional Amount Asset Derivative Fair Value (1) Liability Derivative Notional Amount Liability Derivative Fair Value (1) Asset Derivative Notional Amount Asset Derivative Fair Value (1) Liability Derivative Notional Amount Liability Derivative Fair Value (1) Derivatives designated as hedging instruments: Foreign exchange contracts $ 1,391,228 $ 48,774 $ 870,480 $ 20,415 $ 2,300,609 $ 121,862 $ 302,211 $ 2,936 Total derivatives designated as hedging instruments $ 1,391,228 $ 48,774 $ 870,480 $ 20,415 $ 2,300,609 $ 121,862 $ 302,211 $ 2,936 Derivatives not designated as hedging instruments: Investment Related Derivatives: Interest rate exposure $ 21,166 $ 201 $ 3,222 $ 74 $ 394,597 $ 206 $ 20,782 $ 51 Foreign exchange exposure 377,256 4,767 68,578 872 7,385 403 207,182 4,442 Credit exposure 34,273 729 46,304 12,196 2,408 165 14,270 9,836 Financial market exposure 32,340 3,827 40,898 1,410 46,145 360 33,670 34 Other Non-Investment Derivatives: Foreign exchange contracts 72,634 933 — — — — 81,194 282 Credit exposure 30,075 141 — — 31,060 60 — — Guaranteed minimum income benefit contract 48,558 14,743 48,558 14,743 46,249 13,603 46,249 13,603 Modified coinsurance funds withheld contracts (2) 60,792 — 4,798,271 — 64,947 — 5,401,278 — Total derivatives not designated as hedging instruments $ 677,094 $ 25,341 $ 5,005,831 $ 29,295 $ 592,791 $ 14,797 $ 5,804,625 $ 28,248 ____________ (1) Derivative instruments in an asset or liability position are included within Other assets or Other liabilities, respectively, in the balance sheets on a net basis where the Company has both a legal right of offset and the intention to settle the contracts on a net basis. (2) The fair value movements in derivative assets and liabilities relating to modified coinsurance funds withheld contracts are included within the associated asset or liability at each period end on the face of the balance sheets. Notional amounts associated with reinsurance agreements under which the Company assumes reinsurance risk are recorded as asset derivative notional amounts. Notional amounts associated with the Life Retro Arrangements under which the Company cedes reinsurance risk are recorded as liability derivative notional amounts. Included in the liability derivative notional amount as of September 30, 2015 is the cumulative net realized and unrealized loss on life retrocession embedded derivative of $468.2 million . The following table summarizes information on the gross and net amounts of derivative fair values and associated collateral received related to derivative assets, or collateral provided related to derivative liabilities, reported in other assets and or other liabilities within our consolidated balance sheets as of September 30, 2015 and December 31, 2014 : Gross Amounts Not Offset in the Balance Sheets September 30, 2015 (U.S. dollars in thousands) Gross Amounts Recognized in the Balance Sheets Gross Amounts Offset in the Balance Sheets Net Amounts in the Balance Sheets Financial Instruments Cash Collateral Net Amounts Derivative Assets $ 74,115 $ 3,900 $ 70,215 $ — $ 24,000 $ 46,215 Derivative Liabilities $ 49,710 $ 3,900 $ 45,810 $ — $ — $ 45,810 December 31, 2014 (U.S. dollars in thousands) Derivative Assets $ 136,659 $ 696 $ 135,963 $ — $ 78,580 $ 57,383 Derivative Liabilities $ 31,184 $ 696 $ 30,488 $ — $ — $ 30,488 Derivative instruments in an asset or liability position are included within Other assets or Other liabilities, respectively, in the balance sheets on a net basis where the Company has both a legal right of offset and the intention to settle the contracts on a net basis. The Company often enters into different types of derivative contracts with a single counterparty and these contracts are covered under netting agreements. As of September 30, 2015 and December 31, 2014 , the Company held cash collateral related to foreign currency derivative positions and certain other derivative positions of $24.0 million and $78.6 million , respectively. The assets and liabilities related to the net collateral paid or held were recorded as Other assets and Other liabilities within the balance sheets as the collateral and derivative positions are not intended to be settled on a net basis. (a) Derivative Instruments Designated as Fair Value Hedges The Company designates certain of its derivative instruments as fair value hedges or cash flow hedges and formally and contemporaneously documents all relationships between the hedging instruments and hedged items and links the hedging derivatives to specific assets and liabilities. The Company assesses the effectiveness of the hedge both at inception and on an on-going basis, and determines whether the hedge is highly effective in offsetting changes in fair value or cash flows of the linked hedged item. The Company may use foreign exchange contracts to hedge the fair value of certain fixed income securities as well as to hedge certain net investments in foreign operations. In connection with the Catlin Acquisition and the FX Forwards, certain foreign exchange contracts utilized to hedge the fair value of certain net investments in foreign operations were de-designated as hedging instruments up until the time that the Catlin Acquisition was completed. Thereafter, these foreign exchange contracts were re-designated as hedging instruments. For the nine months ending September 30, 2015, there is no exposure to fair value hedges. The following table provides the total impact on earnings relating to derivative instruments formally designated as fair value hedges along with the impacts of the related hedged items for the nine months ended September 30, 2014: Hedged Items - Amount of Gain/(Loss) Recognized in Income Attributable to Risk Derivatives Designated as Fair Value Hedges: (U.S. dollars in thousands) Gain/(Loss) Recognized in Income on Derivative Fixed Maturity Investments Ineffective Portion of Hedging Relationship - Gain/(Loss) Interest rate exposure $ — Foreign exchange exposure (15,663 ) Total $ (15,663 ) $ 15,407 $ (256 ) The gains (losses) recorded on both the derivative instruments and specific items designated as being hedged as part of the fair value hedging relationships outlined above along with any associated ineffectiveness in the relationships are recorded through Net realized and unrealized gains (losses) on derivative instruments in the income statement. Settlement of Fair Value Hedges A summary of the fair value hedges that have been settled and their impact on results during the indicated periods as well as the remaining balance of fair value hedges and average years remaining to maturity as of September 30, 2015 and 2014 are shown below: Settlement of Fair Value Hedges - Summary Fair Value Hedges - Notes Fair Value Hedges - Deposit Liabilities (U.S. dollars in thousands) 2015 2014 2015 2014 Cumulative reduction to interest expense $ — $ 21,624 $ 101,461 $ 93,042 Remaining balance $ — $ — $ 131,734 $ 140,153 Weighted average years remaining to maturity 0.0 0.0 22.0 23.6 During the second quarter of 2014, the Company negotiated the termination of one of its larger structured indemnity contracts. This contract had previously been designated as a fair value hedge that was settled. The remaining fair value adjustment of $47.0 million that was being amortized as a reduction of interest expense over the remaining term of the contract was recorded as an adjustment to interest expense at the termination date. As a result of the termination, a net decrease of $28.7 million was recorded to interest expense reflecting the realization of the remaining balance of the fair value hedge adjustment, partially offset by an accretion rate adjustment due to changes in cash flows. (b) Derivative Instruments Designated as Hedges of the Net Investment in a Foreign Operation The Company utilizes foreign exchange contracts to hedge the fair value of certain net investments in foreign operations. During the three and nine months ended September 30, 2015 and 2014 , the Company entered into foreign exchange contracts that were formally designated as hedges of investments in foreign subsidiaries, the majority of which have functional currencies of either U.K. sterling or the Euro. There was no ineffectiveness in these transactions. The following table provides the weighted average U.S. dollar equivalent of foreign denominated net assets that were hedged and the resulting derivative gain (loss) that was recorded in the foreign currency translation adjustment, net of tax, account within AOCI for the three and nine months ended September 30, 2015 and 2014 : Derivative Instruments Designated as Hedges of the Net Investment in a Foreign Operation - Summary Three months ended September 30, Nine months ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Weighted average of U.S. dollar equivalent of foreign denominated net assets $ 2,299,875 $ 2,052,469 $ 1,581,470 $ 2,336,671 Derivative gains (losses) (1) $ 29,943 $ 64,593 $ 66,215 $ 63,383 ____________ (1) Derivative gains (losses) from derivative instruments designated as hedges of the net investment in a foreign operation are recorded in the cumulative translation adjustment account within AOCI for each period. (c) Derivative Instruments Not Formally Designated As Hedging Instruments The following table provides the total impact on earnings relating to derivative instruments not formally designated as hedging instruments under authoritative accounting guidance and from the ineffective portion of fair value hedges. The impacts are all recorded through Net realized and unrealized gains (losses) on derivatives in the income statement for the three and nine months ended September 30, 2015 and 2014 : Net Realized and Unrealized Gains (Losses) on Derivative Instruments Three months ended September 30, Nine months ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Investment Related Derivatives: Interest rate exposure $ (5,120 ) $ 3,987 $ (2,046 ) $ 13,313 Foreign exchange exposure (146 ) (576 ) (1,026 ) 1,222 Credit exposure 1,684 384 1,380 391 Financial market exposure (4,309 ) (912 ) (2,913 ) 2,467 Financial Operations Derivatives: Credit exposure — 915 — (3,438 ) Other Non-Investment Derivatives: Foreign exchange contracts 4,063 — 61,494 — Credit exposure (327 ) — 1,151 — Guaranteed minimum income benefit contract — — — 2,257 Modified coinsurance funds withheld contract (3,748 ) 1,333 (913 ) 2,584 Total gain (loss) recognized in income from derivatives not designated as hedging instruments $ (7,903 ) $ 5,131 $ 57,127 $ 18,796 Amount of gain (loss) recognized in income from ineffective portion of fair value hedges — — — (256 ) Net realized and unrealized gains (losses) on derivative instruments $ (7,903 ) $ 5,131 $ 57,127 $ 18,540 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets $ (126,140 ) $ (201,264 ) $ (116,333 ) $ (218,810 ) The Company’s objectives in using these derivatives are explained below. (d)(i) Investment Related Derivatives The Company, either directly or through its investment managers, may use derivative instruments within its investment portfolio, including interest rate swaps, inflation swaps, commodity contracts, total return swaps, credit derivatives (single name and index credit default swaps), options, forward contracts and financial futures (foreign exchange, bond and stock index futures), primarily as a means of economically hedging exposures to interest rate, credit spread, equity price changes and foreign currency risk or, in limited instances, for efficient portfolio management. When using cleared (exchange traded) derivatives, the Company is exposed to the credit risk of the applicable clearing house and of the Company's future commissions merchant. When using uncleared (over-the-counter) derivatives, the Company is exposed to credit risk in the event of non-performance by the counterparties under any derivative contracts, although the Company generally seeks to use credit support arrangements with counterparties to help manage this risk. Investment Related Derivatives – Interest Rate Exposure The Company utilizes risk management and overlay strategies that incorporate the use of derivative financial instruments, primarily to manage its fixed income portfolio duration and net economic exposure to interest rate risks. The Company may also use interest rate swaps to convert certain liabilities from a fixed rate to a variable rate of interest or to convert a variable rate of interest from one basis to another. Investment Related Derivatives – Foreign Exchange Exposure The Company has exposure to foreign currency exchange rate fluctuations through its operations and in its investment portfolio. The Company uses foreign exchange contracts to manage its exposure to the effects of fluctuating foreign currencies on the value of certain of its foreign currency fixed maturities. These contracts are not designated as specific hedges for financial reporting purposes and, therefore, realized and unrealized gains and losses on these contracts are recorded in income in the period in which they occur. These contracts generally have maturities of twelve months or less. In addition, certain of the Company's investment managers may, subject to investment guidelines, enter into forward contracts. Investment Related Derivatives – Credit Exposure Credit derivatives may be purchased within the Company's investment portfolio in the form of single name, basket or index credit default swaps and swaptions, which are used to mitigate credit exposure through a reduction in credit spread duration (i.e., macro credit strategies rather than single-name credit hedging) or exposure to securities of selected issuers, including issuers that are not held in the underlying fixed income portfolio. Investment Related Derivatives – Financial Market Exposure Stock index futures may be purchased within the Company's investment portfolio in order to create synthetic equity exposure and to add value to the portfolio with overlay strategies where market inefficiencies are believed to exist. From time to time, the Company may enter into other financial market exposure derivative contracts on various indices including, but not limited to, inflation and commodity contracts. (d)(ii) Financial Operations Derivatives – Credit Exposure During the fourth quarter of 2014, the remaining financial operations credit derivative exposure, which was written as part of the Company's previous financial lines business and is outside of the Company's investment portfolio, was terminated. The Company has no continuing financial operations derivative credit exposures. (d)(iii) Other Non-Investment Derivatives Foreign Exchange Contracts On January 9, 2015, the Company entered into the FX Forwards with Morgan Stanley Capital Services LLC and Goldman Sachs International. The purpose of the FX Forwards was to mitigate risk of foreign currency exposure related to the Catlin Acquisition. Following the closing of the Catlin Acquisition, the FX Forwards were settled. In connection with the Catlin Acquisition and the FX Forwards, during the year, certain foreign exchange contracts utilized to hedge the fair value of certain net investments in foreign operations were de-designated as hedging instruments. Credit Exposure During the year ended December 31, 2014, the Company entered into a non-investment related credit derivative relating to a number of reference pool mortgage tranches associated with actual mortgage loans that were securitized into agency mortgage-backed securities and sold as Structured Agency Credit Risk Notes. As of September 30, 2015 , there was no reported event of default on this obligation. As of September 30, 2015 and December 31, 2014 , the notional amount outstanding related to the derivative was $30.1 million and $31.1 million , respectively, and the Company had recorded a derivative asset of $0.1 million and $0.1 million , respectively. During the three months ended September 30, 2015 , the Company recorded Net realized and unrealized gains of $0.1 million relating to this credit derivative. The credit derivative is recorded at fair value based upon models developed by the Company. Significant unobservable inputs considered in the valuation include the impact of changes in interest rates, future default, delinquency and prepayment rates, credit spreads, changes in credit quality, and other market factors. Guaranteed Minimum Income Benefit Contract The Company also has derivatives embedded in certain reinsurance contracts. For a certain life reinsurance contract, the Company pays the ceding company a fixed amount equal to the estimated present value of the excess of the guaranteed benefit over the account balance upon the policyholder's election to take the income benefit. The fair value of this derivative is determined based on the present value of expected cash flows. Modified Coinsurance and Funds Withheld Contracts The Company has modified coinsurance and funds withheld reinsurance agreements that provide for a return to be paid to the Company based on a portfolio of fixed income securities. As such, the agreements contain an embedded derivative. The embedded derivative is bifurcated from the funds withheld balance and recorded at fair value with changes in fair value recognized in earnings through Net realized and unrealized gains (losses) on derivative instruments. Modified Coinsurance Funds Withheld Reinsurance Agreements - Life Retrocession Embedded Derivative In addition, the Company has entered into Life Retro Arrangements, as described in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ." The embedded derivative related to the Life Retro Arrangements is recorded at fair value with changes in fair value recognized in earnings through Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets. The change in the value of the life retrocession embedded derivative includes the interest income, realized and unrealized gains and losses on Life Funds Withheld Assets and certain related expenses subsequent to May 30, 2014 as follows: Components of Life Retrocession Embedded Derivative and Derivative Instruments - Life Funds Withheld Assets: Three months ended September 30, Nine Months Ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Interest income - Life Funds Withheld Assets $ (48,809 ) (59,424 ) (147,678 ) (79,368 ) Realized and unrealized gains (losses) - Life Funds Withheld Assets (38,161 ) (113,916 ) 130,047 (112,023 ) Other 121 1,263 276 1,768 Net realized and unrealized gains (losses) on life retrocession embedded derivative $ (86,849 ) $ (172,077 ) $ (17,355 ) $ (189,623 ) Net adjustments related to future policy benefit reserves, net of tax $ (40,668 ) $ (18,376 ) $ (88,551 ) $ (18,376 ) Net realized and unrealized gains (losses) on derivative instruments - Life Funds Withheld Assets $ 1,377 $ (10,811 ) $ (10,427 ) $ (10,811 ) Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets $ (126,140 ) $ (201,264 ) $ (116,333 ) $ (218,810 ) (e) Contingent Credit Features Certain derivative agreements entered into by the Company or its subsidiaries contain credit rating downgrade provisions that permit early termination of the agreements by the counterparty if collateral is not posted following failure to maintain certain credit ratings from one or more of the principal credit rating agencies. If the Company were required to terminate such agreements early due to a credit rating downgrade, it could potentially be in a net liability position at the time of settlement of such agreements. The aggregate fair value of all derivative agreements containing such rating downgrade provisions that were in a liability position and any collateral posted under these agreements as of September 30, 2015 and December 31, 2014 were as follows: Contingent Credit Features - Summary: (U.S. dollars in thousands) September 30, 2015 December 31, 2014 Aggregate fair value of derivative agreements with downgrade provisions in a net liability position $ 15,755 $ 5,770 Collateral posted to counterparty $ — $ —

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and other Intangible Assets	Goodwill and Other Intangible Assets The Company has goodwill and intangible assets of $2.2 billion and $448.0 million at September 30, 2015 and December 31, 2014 , respectively. In the third quarter of 2015, as a result of the transaction described in Note 3(b), "Acquisitions and Disposals - New Energy Risk ," the Company recognized additional goodwill of approximately $13.4 million . The transaction was accounted for using the acquisition method under which the Company recorded the identifiable assets acquired and liabilities assumed at their acquisition date fair values, and recorded as goodwill the excess of the sum of a) over b) - in which a) represents the aggregate of: i) the consideration transferred, ii) the fair value of noncontrolling interest in the acquiree, and iii) the acquisition-date fair value of the Company's previously held equity interest in the acquiree; and b) represents the net assets acquired in the transaction. In the second quarter of 2015, as a result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ," the Company recognized additional intangible assets. The transaction was accounted for using the acquisition method under which the Company recorded the identifiable assets acquired, including indefinite-lived and definite-lived intangible assets, and liabilities assumed, at their Acquisition Date fair values, and recorded the excess of consideration transferred over the net assets acquired as goodwill. During the first quarter of 2014, goodwill and intangible assets increased as a result of the completion of an acquisition. The transaction was accounted for using the acquisition method under which the Company recorded the identifiable assets acquired - including definite-lived intangible assets, and liabilities assumed, at their acquisition date fair values, and recorded the excess of consideration transferred over the net assets acquired as goodwill. The following table presents an analysis of intangible assets broken down between goodwill, intangible assets with an indefinite life and intangible assets with a definite life for the nine months ended September 30, 2015 : (U.S. dollars in thousands) Goodwill Intangible Intangible Total Balance at December 31, 2014 $ 415,936 $ 15,366 $ 16,650 $ 447,952 Additions 791,433 673,000 315,000 1,779,433 Amortization — — (9,922 ) (9,922 ) Foreign Currency Translation (3,775 ) — — (3,775 ) Balance at September 30, 2015 $ 1,203,594 $ 688,366 $ 321,728 $ 2,213,688 The following table summarizes the intangible assets and their related useful lives recorded in connection with the Catlin Acquisition as of the Acquisition Date: (U.S. dollars in thousands) Amount Estimated Useful Life Lloyd's - Syndicate capacity $ 660,000 Indefinite Insurance licenses 13,000 Indefinite Total identified indefinite life intangible assets $ 673,000 Lloyd's - Managing agent contracts 15,000 15 years Distribution network 290,000 20 years Trademarks / Trade names 10,000 2 years Total identified definite life intangible assets $ 315,000 Total identified intangible assets $ 988,000 An explanation of the intangible assets is as follows: • Lloyd's - Syndicate capacity - The syndicate capacity of two Lloyd's syndicates, which will allow the Company to write insurance business in the Lloyd's market globally and realize the profits from that business. The value of the syndicate capacity includes the reputational value of participation in the Lloyd's market, and the value of trade names and licenses associated with syndicate ownership. • Insurance licenses - U.S. State insurance licenses owned by Catlin at the time of the Catlin Acquisition. • Lloyds - Managing agent contracts - As the managing agent for certain Lloyd's syndicates, the Company has contracts with the syndicate members to provide underwriting services, for which it earns managing agent fees and a profit commission. • Distribution network - A network of hundreds of retail and wholesale brokers worldwide, including specialty and regional brokerages, which allow the Company to form closer relationships with clients and brokers worldwide and aids business retention. • Trademarks / Trade names - The Catlin trademarks / trade names are utilized to attract customers for the turnkey solutions provided under the Company's managing agent contracts, and to generate premiums from the non-Lloyd's platform underwriting products for which the Catlin brand is known.

Share Capital

Share Capital	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Share Capital	Share Capital (a) Authorized and Issued Ordinary Shares In connection with the Catlin Acquisition described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ," the Company issued 49.9 million ordinary shares to Catlin shareholders, which had an aggregate value as of the Acquisition Date of $1.85 billion . The following table is a summary of ordinary shares issued and outstanding for the nine months ended September 30, 2015 and the year ended December 31, 2014: (in thousands) September 30, 2015 December 31, 2014 Balance – beginning of period 255,183 278,253 Exercise of options 374 424 Net issuance of restricted shares 1,567 1,246 Share buybacks (1) (7,742 ) (24,740 ) Issue of shares 49,935 — Balance – end of period 299,317 255,183 ____________ (1) Includes share buybacks associated with authorized share buyback programs as well as purchases related to satisfying tax withholding obligations of employees in connection with the vesting of restricted shares granted under the Company's equity compensation programs. Buybacks of Ordinary Shares On February 21, 2014, XL-Ireland announced that its Board of Directors approved an increase to the Share Buyback Program (the "February 2014 Program"), authorizing the purchase of up to $1.0 billion of ordinary shares, which included the amounts that remained under the previous Share Buyback Program. During the three and nine months ended September 30, 2015 , the Company purchased and canceled 1.6 million and 4.5 million ordinary shares, respectively, under the February 2014 Program for $60.0 million and $170.0 million , respectively. On August 6, 2015, XL-Ireland announced that its Board of Directors approved a new share buyback program, authorizing the purchase of up to $1.0 billion of ordinary shares (the "August 2015 Program"). This authorization also canceled approximately $97.6 million remaining under the February 2014 Program. During the three and nine months ended September 30, 2015 , the Company purchased and canceled 3.2 million ordinary shares under the August 2015 Program for $120.0 million . As of September 30, 2015 , $880.0 million remained available for purchase under the August 2015 Program. Acquisition of Non-controlling Preferred Shares In connection with the Catlin Acquisition described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ," the Company acquired 0.6 million non-cumulative perpetual preferred shares issued by Catlin-Bermuda, par value of $0.01 per share, with liquidation preference of $1,000 per share, plus declared and unpaid dividends ("CICL Prefs"). Dividends at a rate of 7.249 percent on the liquidation preference are payable semi-annually on January 19 and July 19 in arrears as and when declared up to but not including January 2017. Thereafter, if the CICL-Prefs have not yet been redeemed, dividends will be payable quarterly at a rate equal to 2.975 percent plus the three-month LIBOR rate of the liquidation preference. The fair value of the outstanding CICL-Prefs on the date of the Catlin Acquisition was $562.3 million , which was based on the last trading price of such securities prior to the Catlin Acquisition. (b) Stock Plans The Company's performance incentive programs provide for grants of stock options, restricted stock, equity-classed restricted stock units, liability-classed restricted stock units, performance units and stock appreciation rights. Share-based compensation granted by the Company generally contains a vesting period of three or four years, and certain awards also contain performance conditions. The Company records compensation expense related to each award over its vesting period, incorporating the best estimate of the expected outcome of performance conditions where applicable. Compensation expense is generally recorded on a straight line basis over the vesting period of an award. See Item 8, Note 20, "Share Capital ," to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2014 for further information on the Company's performance incentive programs and associated accounting. During the nine months ended September 30, 2015 , the Company granted approximately 2.0 million stock options with a weighted-average grant date fair value of $6.51 per option. The fair value of the options issued was estimated on the date of grant using the Black-Scholes option pricing model using the following weighted average assumptions: Dividend yield 2.00 % Risk free interest rate 1.70 % Volatility 21.6 % Expected lives 6.0 years During the nine months ended September 30, 2015 , the Company granted approximately 43,457 restricted stock awards to certain employees and directors of the Company and its subsidiaries with an aggregate grant date fair value of approximately $1.6 million . The award recipients generally have the rights and privileges of a shareholder as to the restricted stock, including the right to receive dividends contingent upon the vesting of the restricted stock and the right to vote such restricted stock. The recipients are not entitled to receive delivery of a stock certificate prior to vesting nor may any restricted stock be sold, transferred, pledged, or otherwise disposed of prior to the satisfaction of all vesting requirements. During the nine months ended September 30, 2015 , the Company granted approximately 1.5 million equity-classed restricted stock units to certain employees with an aggregate grant date fair value of approximately $55.5 million . Each equity-classed restricted stock unit represents the Company's obligation to deliver to the holder one ordinary share, and grants vest in three equal installments upon the first, second and third anniversaries of the date of grant. Equity-classed restricted stock units are granted at the closing market price on the day of grant and entitle the holder to receive dividends declared and paid in the form of additional ordinary shares contingent upon vesting. During the nine months ended September 30, 2015 , the Company granted approximately 2.6 million liability-classed stock units to certain employees with an aggregate grant date fair value of approximately $94.5 million . Each liability-classed restricted stock unit represents the Company's obligation to deliver to the holder a cash payment equivalent to the value of one ordinary share. The grants may vest either in three equal installments upon the first, second and third anniversaries of the date of grant; or in two equal installments upon the first and second anniversaries of the date of grant. Liability-classed restricted stock units are granted at the closing market price on the day of grant and entitle the holder to receive dividends declared and are paid in cash contingent upon vesting. During the nine months ended September 30, 2015 , the Company granted approximately 0.8 million performance units (representing a potential maximum share payout of approximately 1.6 million ordinary shares) to certain employees with an aggregate grant date fair value of approximately $28.1 million . The performance units issued in 2015 vest after approximately three years, subject to the achievement of stated market metrics, and entitle the holder to ordinary shares of the Company. Each grant of performance units has a target number of shares, with final payouts ranging from 0% to 200% of the grant amount depending upon the achievement of stated market metrics along with each employee's continued service through the vesting date. Performance units issued prior to 2015 have a similar vesting schedule and range of a target number of shares, but vesting and payout are dependent upon the achievement of stated relative and absolute financial performance metrics along with each employee's continued service through the vesting date. Furthermore, performance units granted in the current year are granted at the closing market price on the day of grant and entitle the holder to receive dividends declared and paid in the form of additional ordinary shares contingent upon vesting. There are no dividend rights associated with performance units issued prior to 2015.

Notes Payable and Debt and Fina

Notes Payable and Debt and Financing Arrangements	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Notes Payable and Debt and Financing Arrangements	Notes Payable and Debt and Financing Arrangements As of September 30, 2015 , the Company's financing structure, which includes senior and subordinated notes, and bank and loan facilities available from a variety of sources, including commercial banks, is as follows: (U.S. dollars in thousands) September 30, 2015 December 31, 2014 Commitment/ Debt (1) In Use/ Outstanding (2) Commitment/ Debt (1) In Use/ Outstanding (2) Debt: 2.30% Senior Notes due 2018 300,000 297,847 300,000 297,344 5.75% Senior Notes due 2021 400,000 397,415 400,000 397,092 6.375% Senior Notes due 2024 350,000 349,002 350,000 348,920 4.45% Subordinated Notes due 2025 500,000 492,318 — — 6.25% Senior Notes due 2027 325,000 323,179 325,000 323,062 Variable Rate Note, face amount €7m, due 2035 7,823 7,336 — — Variable Rate Note, face amount $27m, due 2036 27,000 25,280 — — Variable Rate Note, face amount $31m, due 2036 31,300 29,305 — — Variable Rate Note, face amount $10m, due 2036 9,800 9,175 — — Variable Rate Note, face amount €11m, due 2036 12,294 11,528 — — 5.25% Senior Notes due 2043 300,000 296,261 300,000 296,162 5.5% Subordinated Notes due 2045 500,000 488,271 — — Total debt carrying value $ 2,763,217 $ 2,726,917 $ 1,675,000 $ 1,662,580 _______________ (1) Excluded from the table are revolving credit facilities of $1.5 billion and $1.6 billion as of September 30, 2015 and December 31, 2014 , respectively. As of September 30, 2015 and December 31, 2014 , $455.9 million and $606.1 million , respectively, were utilized under these facilities to issue letters of credit, leaving $1.0 billion and $ 968.9 million , respectively, available for use under the revolving credit facilities. (2) "In Use/Outstanding" data represent September 30, 2015 and December 31, 2014 accreted values. (a) Notes Payable and Debt With the exception of the debt acquired as part of the Catlin Acquisition, as described below, all outstanding debt of the Company as of September 30, 2015 and December 31, 2014 was issued by XL-Cayman, a 100% owned subsidiary of XL-Ireland. XL-Ireland does not have significant assets or operations independent of XL-Cayman. XL-Cayman's outstanding debt is fully and unconditionally guaranteed by XL-Ireland. The ability of XL-Cayman, like that of the Company, to obtain funds from its subsidiaries to satisfy any of its obligations, including under guarantees, is subject to certain contractual restrictions, applicable laws and statutory requirements of the various countries in which the subsidiaries operate, including, among others, Bermuda, the United States, Ireland, Switzerland and the United Kingdom. For details of the required statutory capital and surplus for the principal operating subsidiaries of the Company, see Item 8, Note 25, "Statutory Financial Data ," to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2014 . On March 30, 2015, XL-Cayman issued $500 million of subordinated notes due March 2025, with a fixed coupon of 4.45% , that are guaranteed by XL-Ireland. The notes are listed on the New York Stock Exchange. The notes were issued at 99.633% of the face amount and net proceeds were $492.2 million . Related expenses of the offering amounted to approximately $5.9 million . These costs were deferred and will be amortized over the term of the subordinated notes. On March 30, 2015, XL-Cayman issued $500 million of subordinated notes due March 2045, with a fixed coupon of 5.5% , that are guaranteed by XL-Ireland. The notes are listed on the New York Stock Exchange. The notes were issued at 99.115% of the face amount and net proceeds were $488.4 million . Related expenses of the offering amounted to approximately $7.2 million . These costs were deferred and will be amortized over the term of the subordinated notes. As a result of the Catlin Acquisition, the Company assumed the following liabilities of Catlin: • Variable rate unsecured subordinated notes in the amounts of €7 million and $27 million due March 2035 and March 2036, respectively, issued by Catlin Underwriting (formerly Wellington Underwriting plc) in May 2006. The notes are subordinated to the claims of all senior creditors, as defined in the agreement governing the notes. The notes pay interest at a floating rate based on the rate on three-month deposits in U.S. dollars plus a margin of 295 basis points and 317 basis points, respectively. Interest is payable quarterly in arrears. The notes are redeemable at the discretion of the issuer. • Variable rate unsecured subordinated notes in the amounts of $31 million , $10 million and €11 million due September 2036, issued by Catlin Underwriting, in July 2006. The notes are subordinated to the claims of all senior creditors, as defined in the agreement governing the notes. The notes pay interest at a floating rate based on the rate on three-month deposits in U.S. dollars plus a margin of 310 basis points, 300 basis points and 300 basis points, respectively. Interest is payable quarterly in arrears. The notes are redeemable at the discretion of the issuer. XL-Cayman and the Company were in compliance with all covenants by significant margins as of September 30, 2015 , and XL-Cayman and the Company currently remain in compliance with all covenants. (b) Letter of Credit Facilities and Other Sources of Collateral The Company has letter of credit facilities provided on both syndicated and bilateral bases from commercial banks. These facilities are utilized primarily to support non-admitted insurance and reinsurance operations in the U.S. and capital requirements at Lloyd’s. The Company’s letter of credit facilities and revolving credit facilities as of September 30, 2015 and December 31, 2014 were as follows: Letter of Credit Summary: (U.S. dollars in thousands except percentages) September 30, 2015 (1) December 31, 2014 (1) Revolving credit facilities (2) (3) $ 1,039,100 $ 968,900 Available letter of credit facilities - commitments (4) $ 4,850,000 $ 3,575,000 Available letter of credit facilities - in use $ 2,538,499 $ 1,790,561 Collateralized by certain assets of the Company’s investment portfolio 49.9 % 66.2 % ____________ (1) As of September 30, 2015 and December 31, 2014 , there were eighteen and eight available letter of credit facilities, respectively. (2) As of September 30, 2015 and December 31, 2014 , $976.1 million and $968.9 million , respectively, of revolving credit was available under the Company's syndicated unsecured credit agreement, which currently provides for up to $1 billion of revolving credit loans. The Company has the option to increase the size of the facilities under the syndicated secured and unsecured credit agreements by an additional $500 million across both facilities. Two bilateral facilities assumed as a result of the Catlin Acquisition with commitments totaling $150.0 million also provide for revolving credit loans. As of September 30, 2015 , $63.0 million of revolving credit was available to draw under these facilities. (3) The credit agreements with Citicorp USA, Inc. currently provide for the issuance of letters of credit and revolving credit loans up to an aggregate amount of $345.0 million , compared to $575.0 million available under the credit agreements with Citicorp USA, Inc. as of December 31, 2014 . As of September 30, 2015 , $345.0 million of letters of credit were issued under these agreements, and therefore no amounts are included in this line as available to draw under these facilities. The Company also has the option to increase the maximum amount of the letters of credit and revolving credit loans available under its credit agreements with Citicorp USA, Inc. with the lender's and issuing lender's consent. (4) The available letter of credit facilities include approximately $1 billion that is also included in the "revolving credit facilities" line in this table. As a result of the Catlin Acquisition, the Company has assumed the following letter of credit facilities: • A $450 million unsecured multi-bank facility available for utilization by certain subsidiaries and guaranteed by Green Holdings. The facility has a termination date of December 31, 2016. • A bilateral facility available for utilization by Catlin-Bermuda, collateralized by pledged financial assets. As of September 30, 2015 , $136 million of letters of credit were issued under this facility. • A bilateral facility available for utilization by Catlin Re Switzerland Ltd, collateralized by pledged financial assets. As of September 30, 2015 , $49 million of letters of credit were issued under this facility. • Four unsecured bilateral facilities available for utilization by Catlin-Bermuda and guaranteed by Green Holdings for Funds at Lloyd's purposes, amounting to a total of $375 million . One of the facilities has an expiration date of December 31, 2017, while the other three have expiration dates of December 31, 2018. • An unsecured bilateral facility valued in Australian dollars at A$50 million , available for utilization by certain subsidiaries of Catlin and guaranteed by Green Holdings, for the purpose of providing collateral to Australian beneficiaries. • Two unsecured bilateral revolving credit and letter of credit facilities, available for utilization by certain subsidiaries of Catlin and guaranteed by Green Holdings amounting to $150 million . • A facility managed by Lloyd's, acting for Catlin Syndicate 2003. As of September 30, 2015 , $10 million of letters of credit were issued under this facility. • Catlin, Inc. has letters of credit amounting to $1 million issued for the benefit of various parties. On September 8, 2015, XL-Cayman entered into a new credit agreement with Goldman Sachs Mortgage Company, as administrative agent and issuing lender, and a continuing agreement for standby letters of credit with Goldman Sachs Bank USA. On September 9, 14, and 16, 2015, XL-Cayman entered into first, second and third amendments, respectively, to such credit agreement (as amended, the Goldman Credit Agreement”). XL-Cayman entered into the Goldman Credit Agreement to replace the letter of credit capacity under a credit agreement with Citicorp USA, Inc. initially entered into on August 6, 2013 that expired by its terms on September 20, 2015. The Goldman Credit Agreement and the continuing agreement for standby letters of credit provide for issuance of letters of credit in an aggregate amount of up to $200 million . XL-Cayman has the option to increase the maximum amount of letters of credit available under the Goldman Credit Agreement with the lender's and issuing lender's consent. The commitments under the Goldman Credit Agreement expire on, and such credit facility is available until, the earlier of (i) September 20, 2017 and (ii) the date of termination in whole of the commitments upon an optional termination or reduction of the commitments by the account parties or upon the occurrence of certain events of default. For details regarding the remaining facilities, see Item 8, Note 15(b), "Notes Payable and Debt and Financing Arrangements - Letter of Credit Facilities and Other Sources of Collateral ," to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2014 .

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions (a) Investment Manager Affiliates As of September 30, 2015 and 2014 , the Company owned minority stakes in six independent investment management companies ("Investment Manager Affiliates"), that are actively managing client capital and seeking growth opportunities. The Company seeks to develop relationships with specialty investment management organizations, generally acquiring an equity interest in the business. The Company also invests in certain of the funds and limited partnerships and other legal entities managed by these affiliates, and, through these funds and partnerships, pays management and performance fees to the Company's Investment Manager Affiliates. See Item 8, Note 7, "Investments in Affiliates ," to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2014 . (b) Assumed Reinsurance Contracts In the normal course of business, the Company enters into assumed reinsurance contracts with certain of its other strategic affiliates, or their subsidiaries. Management believes that these transactions are conducted at market rates consistent with negotiated arm's-length contracts. During the three and nine months ended September 30, 2015 and 2014 , these contracts resulted in net premiums written, net claims incurred and acquisition costs as summarized below: (U.S. dollars in thousands) Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Net premiums written $ 5,075 $ 31,981 $ 36,596 $ 68,172 Net losses and loss expenses incurred $ 1,402 $ 12,738 $ 10,567 $ 27,038 Acquisition costs $ 1,874 $ 10,969 $ 12,269 $ 26,522 Results through April 1, 2015 include amounts under an assumed reinsurance contract with a wholly-owned subsidiary of ARX, an insurance operating affiliate of the Company to that date. The Company disposed of its investment in ARX on April 1, 2015, and thus, after that date, all amounts under this contract are no longer reported as related party transactions. See Note 3(d), "Acquisitions and Disposals - Sale of Strategic Operating Affiliate ." (c) New Ocean Commencing in 2014, several of the Company’s wholly-owned subsidiaries retrocede assumed reinsurance business to special purpose reinsurers that receive capital from funds managed by the Company's subsidiary, New Ocean Capital Management Limited, a Bermuda based company, ("New Ocean"), as discussed in Note 12, "Variable Interest Entities ". Underwriting administration services are provided to the special purpose reinsurers by other subsidiaries of the Company under service fee agreements negotiated at arm's-length, while investment advisory services are provided by New Ocean. During the three and nine months ended September 30, 2015 , ceded premiums earned, ceded losses and loss expenses incurred, ceding commission income, and other fee income related to these retrocessional contracts were not material to the Company. Management believes that these transactions are conducted at market rates consistent with negotiated arm's-length contracts. (d) New Energy On July 24, 2015, as described in Note 3(b), "Acquisitions and Disposals - New Energy Risk ," the Company completed its acquisition of 63.63% of the additional shares of New Energy for approximately $8.8 million , increasing its majority ownership of the entity to 94.79% . These shares are held within the XL Innovate Fund. A substantial portion of the additional shares were purchased at arm's length directly from the family trusts of a Company employee, based on a market valuation of New Energy performed by an independent 3rd party provider. The remaining 5.21% of equity shares of New Energy held by the family trusts of the employee were then contributed in-kind to XL Innovate Fund based on the share price implied by the independent valuation. Such contribution was made in partial satisfaction of the employee's aggregate 5.21% investment commitment to the Fund and resulted in XL Innovate Fund owning 100% of the net equity of New Energy, and the family trusts of the employee owning a 5.21% non-controlling equity interest in XL Innovate Fund. The employee serves as a member of the board of directors of both New Energy and XL Innovate Fund, and maintains responsibility over the business generated by New Energy. There were no other material transactions between the Company and this employee for the three and nine months ended September 30, 2015 .

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2015
Variable Interest Entities Disclosure [Abstract]
Variable Interest Entities	Variable Interest Entities At times, the Company has utilized VIEs both indirectly and directly in the ordinary course of the Company's business. During the third quarter of 2013, the Company, along with other investors, formed New Ocean to act as an investment manager focused on providing third-party investors access to insurance-linked securities and other insurance and reinsurance capital markets products. The Company holds a majority voting interest in New Ocean through its ownership of common shares and, accordingly, the financial statements of New Ocean have been included in the consolidated financial statements of the Company. None of the assets, liabilities, revenues or net income of New Ocean were material to the Company during the three and nine months ended September 30, 2015 . The equity interest attributable to third party investors in New Ocean recorded in the Company’s Unaudited Consolidated Balance Sheets as "Non-controlling interest in equity of consolidated subsidiaries" was $0.4 million and $0.2 million as of September 30, 2015 and December 31, 2014 , respectively. During the fourth quarter of 2013, the Company, along with other investors, invested in a new Bermuda-based company, New Ocean Focus Cat Fund Ltd. ("New Ocean FCFL"), which is considered a VIE under GAAP. During the second quarter of 2014, the Company formed another new Bermuda-based investment company, New Ocean Market Value Cat Fund, Ltd. ("New Ocean MVCFL"), which is also considered a VIE under GAAP. New Ocean MVCFL primarily invests in insurance-linked securities, with a current focus on catastrophe bonds. During the year ended December 31, 2014, New Ocean FCFL invested in a special purpose Bermuda reinsurer, Vector Reinsurance Ltd ("Vector Re"), formed for the purpose of underwriting collateralized excess of loss reinsurance with a focus on global property catastrophe risks. During the first quarter of 2015, New Ocean MVCFL also invested in Vector Re. Most of Vector Re’s current underwriting activity relates to reinsurance business assumed from the Company's subsidiaries. Underwriting administration and claims services are provided to Vector Re by the Company under service fee contracts which management believes were negotiated at arm's-length, while investment advisory services are provided by New Ocean. The Company currently holds majority equity interests, which are considered to be the controlling financial interests, in New Ocean FCFL and New Ocean MVCFL, and by extension, Vector Re. Accordingly, included in the consolidated financial statements of the Company are the total net assets of New Ocean FCFL, New Ocean MVCFL and Vector Re of $141.5 million and $139.9 million as of September 30, 2015 and December 31, 2014 , respectively. The Company’s shares of revenue and net income in these VIEs were not material to the Company for the three and nine months ended September 30, 2015 . All inter-company transactions between the Company's entities have been eliminated in consolidation. The equity interest attributable to third party investors in New Ocean FCFL, New Ocean MVCFL and Vector Re recorded in the Company’s Consolidated Balance Sheets as "Non-controlling interest in equity of consolidated subsidiaries" was $55.8 million and $58.4 million as of September 30, 2015 and December 31, 2014 , respectively.

Computation of Earnings Per Ord

Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent	Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent The following table sets forth the computation of basic and diluted earnings per ordinary share for the three and nine months ended September 30, 2015 and 2014 : Three Months Ended September 30, Nine Months Ended September 30, (U.S. dollars in thousands, except per share amounts) 2015 2014 2015 2014 Basic earnings per ordinary share & ordinary share equivalents outstanding: Net income (loss) attributable to ordinary shareholders $ 27,282 $ 72,384 $ 978,602 $ 48,841 Weighted average ordinary shares outstanding, in thousands - basic 301,867 264,353 282,506 270,494 Basic earnings per ordinary share & ordinary share equivalents outstanding $ 0.09 $ 0.27 $ 3.46 $ 0.18 Diluted earnings per ordinary share & ordinary share equivalents outstanding: Weighted average ordinary shares outstanding, in thousands - basic 301,867 264,353 282,506 270,494 Impact of share-based compensation and certain conversion features, in thousands 5,087 4,787 4,967 4,418 Weighted average ordinary shares outstanding, in thousands - diluted 306,954 269,140 287,473 274,912 Diluted earnings per ordinary share & ordinary share equivalents outstanding $ 0.09 $ 0.27 $ 3.40 $ 0.18 Dividends per ordinary share $ 0.20 $ 0.16 $ 0.52 $ 0.48 For the three months ended September 30, 2015 and 2014 , and for the nine months ended September 30, 2015 and 2014 , ordinary shares available for issuance under share-based compensation plans of 2.6 million and 4.7 million , respectively, and 2.4 million and 5.5 million , respectively, were not included in the calculation of diluted earnings per ordinary share because the assumed exercise or issuance of such shares would be anti-dilutive.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies (a) Financial Guarantee Exposures The Company's outstanding financial guarantee contracts as of September 30, 2015 provide credit support for a variety of collateral types with the exposures comprised of an aggregate amount of $80.8 million notional financial guarantee on two notes backed by zero coupon long dated bonds and bank perpetual securities, including some issued by European financial institutions. As of September 30, 2015 and December 31, 2014, the total gross claim liability recorded was nil and the contracts had a weighted average contractual term to maturity of 24.5 years and 25.2 years , respectively. Surveillance procedures to track and monitor credit deteriorations in the insured financial obligations are performed by the primary obligors for each transaction on the Company's behalf. Information regarding the performance status and updated exposure values is provided to the Company on a quarterly basis and evaluated by management in recording claims reserves. As of September 30, 2015 , there were no reported events of default on these obligations. (b) Litigation The Company and its subsidiaries are subject to litigation and arbitration in the normal course of business. These lawsuits and arbitrations principally involve claims on policies of insurance and contracts of reinsurance and are typical for the Company and for the property and casualty insurance and reinsurance industry in general. Such claims proceedings are considered in connection with the Company's loss and loss expense reserves. Reserves in varying amounts may or may not be established in respect of particular claims proceedings based on many factors, including the legal merits thereof. In addition to litigation relating to insurance and reinsurance claims, the Company and its subsidiaries are subject to lawsuits and regulatory actions in the normal course of business that do not arise from or directly relate to claims on insurance or reinsurance policies. This category of business litigation typically involves, among other things, allegations of underwriting errors or misconduct, employment claims, regulatory activity, shareholder disputes or disputes arising from business ventures. The status of these legal actions is actively monitored by management. Legal actions are subject to inherent uncertainties, and future events could change management's assessment of the probability or estimated amount of potential losses from pending or threatened legal actions. Based on available information, it is the opinion of management that the ultimate resolution of pending or threatened legal actions other than claims proceedings, both individually and in the aggregate, will not result in losses having a material adverse effect on the Company's financial position or liquidity as of September 30, 2015 . If management believes that, based on available information, it is at least reasonably possible that a material loss (or additional material loss in excess of any accrual) will be incurred in connection with any legal actions, the Company discloses an estimate of the possible loss or range of loss, either individually or in the aggregate, as appropriate, if such an estimate can be made, or discloses that an estimate cannot be made. Based on the Company's assessment as of September 30, 2015 , no such disclosures were considered necessary.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2015
Comprehensive Income Loss Note [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) The changes in AOCI, net of tax, by component for the three and nine months ended September 30, 2015 and 2014 are as follows: Three months ended September 30, 2015 (U.S. dollars in thousands) Unrealized Gains (Losses) on Investments (1) OTTI Losses Recognized in AOCI Foreign Currency Translation Adjustments Underfunded Pension Liability Cash Flow Hedge Total Balance, beginning of period, net of tax $ 1,168,964 $ (64,614 ) $ (9,508 ) $ (21,143 ) $ 2,475 $ 1,076,174 OCI before reclassifications (4,334 ) — (24,267 ) 93 — (28,508 ) Amounts reclassified from AOCI (94,393 ) 2,318 — — 12 (92,063 ) Tax benefit (expense) (2,213 ) (181 ) 1,873 — — (521 ) Net current period OCI - net of tax (100,940 ) 2,137 (22,394 ) 93 12 (121,092 ) Balance, end of period, net of tax $ 1,068,024 $ (62,477 ) $ (31,902 ) $ (21,050 ) $ 2,487 $ 955,082 Three months ended September 30, 2014 (U.S. dollars in thousands) Balance, beginning of period, net of tax $ 1,301,178 $ (84,258 ) $ 1,059 $ (13,278 ) $ 2,333 $ 1,207,034 OCI before reclassifications 51,133 — (14,167 ) 418 — 37,384 Amounts reclassified from AOCI (28,795 ) 6,078 87 — 83 (22,547 ) Tax benefit (expense) 7,906 (115 ) 2,267 — — 10,058 Net current period OCI - net of tax 30,244 5,963 (11,813 ) 418 83 24,895 Balance, end of period, net of tax $ 1,331,422 $ (78,295 ) $ (10,754 ) $ (12,860 ) $ 2,416 $ 1,231,929 Nine months ended September 30, 2015 (U.S. dollars in thousands) Balance, beginning of period, net of tax $ 1,590,114 $ (76,047 ) $ (11,188 ) $ (20,789 ) $ 2,368 $ 1,484,458 OCI before reclassifications (294,341 ) — (28,225 ) (261 ) — (322,827 ) Amounts reclassified from AOCI (256,731 ) 13,916 — — 119 (242,696 ) Tax benefit (expense) 28,982 (346 ) 7,511 — — 36,147 Net current period OCI - net of tax (522,090 ) 13,570 (20,714 ) (261 ) 119 (529,376 ) Balance, end of period, net of tax $ 1,068,024 $ (62,477 ) $ (31,902 ) $ (21,050 ) $ 2,487 $ 955,082 Nine months ended September 30, 2014 (U.S. dollars in thousands) Balance, beginning of period, net of tax $ 822,432 $ (89,190 ) $ 14,541 $ (13,239 ) $ 2,113 $ 736,657 OCI before reclassifications 679,732 — (23,688 ) 379 — 656,423 Amounts reclassified from AOCI (125,770 ) 11,127 87 — 303 (114,253 ) Tax benefit (expense) (44,972 ) (232 ) (1,694 ) — — (46,898 ) Net current period OCI - net of tax 508,990 10,895 (25,295 ) 379 303 495,272 Balance, end of period, net of tax $ 1,331,422 $ (78,295 ) $ (10,754 ) $ (12,860 ) $ 2,416 $ 1,231,929 ____________ (1) Included in these amounts is the impact of Shadow Adjustments as defined in Note 6, "Investments .". As of December 31, 2014 the cumulative impact of the Shadow Adjustments was $445.1 million . During the nine months ended September 30, 2015 , net movements of $(127.4) million were recorded, resulting in a total cumulative net impact of Shadow Adjustments on future policy benefit reserves of $317.7 million as of September 30, 2015 . The reclassifications out of AOCI along with the associated income statement line items affected by component, and the total related tax (expense) benefit for the three and nine months ended September 30, 2015 and 2014 are as follows: Gross Amount Reclassified From AOCI Details About AOCI Components (U.S. dollars in thousands) Three months ended September 30, 2015 Three months ended September 30, 2014 Nine months ended September 30, 2015 Nine months ended September 30, 2014 Affected Line Item in the Statement of Income Unrealized gains and losses on investments: $ (97,761 ) $ (18,665 ) $ (247,339 ) $ (151,049 ) Net realized gains (losses) on investments sold and net unrealized gains (losses) on investments Trading 44,036 8,246 79,158 43,655 OTTI on investments $ (40,668 ) $ (18,376 ) $ (88,550 ) $ (18,376 ) Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets $ (94,393 ) $ (28,795 ) $ (256,731 ) $ (125,770 ) Total before tax 1,253 956 5,034 5,108 Provision (benefit) for income tax $ (93,140 ) $ (27,839 ) $ (251,697 ) $ (120,662 ) Net of tax OTTI losses recognized in OCI: $ 1,617 $ 5,686 $ 13,086 $ 9,030 Net realized gains (losses) on investments sold 701 392 830 2,097 OTTI on investments transferred to (from) OCI $ 2,318 $ 6,078 $ 13,916 $ 11,127 Total before tax (10 ) (3 ) (25 ) (120 ) Provision (benefit) for income tax $ 2,308 $ 6,075 $ 13,891 $ 11,007 Net of tax Foreign currency translation: Foreign exchange relating to affiliate investments $ — $ 87 $ — $ 87 Exchange gains (losses) - before tax — — — — Provision (benefit) for income tax $ — $ 87 $ — $ 87 Net of tax Gains and losses on cash flow hedges: Interest rate contracts $ 12 $ 83 $ 119 $ 303 Interest Expense — — — — Provision (benefit) for income tax $ 12 $ 83 $ 119 $ 303 Net of tax Total reclassifications for the period, gross of tax $ (92,063 ) $ (22,547 ) $ (242,696 ) $ (114,253 ) Tax benefit (expense) 1,243 953 5,009 4,988 Total reclassifications for the period, net of tax $ (90,820 ) $ (21,594 ) $ (237,687 ) $ (109,265 )

Significant Accounting Polici23

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Restricted cash	Restricted Cash Restricted cash represents cash and cash equivalents that the Company is a) holding for the benefit of a third party and is legally or contractually restricted as to withdrawal or usage for general corporate purposes; and b) not replaceable by another type of asset other than cash or cash equivalents, under the terms of the Company's contractual arrangements with such third parties. Restricted cash includes cash and cash equivalents held pursuant to the terms of the Company's contractual obligations of the transaction described in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ."
Reinsurance	Reinsurance During the three months ended September 30, 2014, the Company recorded $20.0 million , net of tax, to premiums earned and associated tax accruals related to reinstatement premiums due under assumed reinsurance contracts arising from unpaid losses and loss expenses reported in a prior period. We evaluated the quantitative and qualitative aspects of this correction and concluded that the impact of recognizing it was not material to the consolidated financial statements, nor is it material to previously issued consolidated financial statements in prior periods.
Recent accounting pronouncements	Recent Accounting Pronouncements In February 2015, the Financial Accounting Standards Board ("FASB") issued an accounting standards update concerning consolidation of certain legal entities. Under this new guidance, all legal entities are required to evaluate whether they should consolidate certain legal entities. The guidance: (1) modifies the evaluation of whether limited partnerships and similar legal entities are variable interest entities ("VIEs") or voting interest entities; (2) eliminates the presumption that a general partner should consolidate a limited partnership; (3) affects the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships; and (4) provides a scope exception from consolidation guidance for certain reporting entities. Upon adoption of the new guidance, differing requirements for performing a consolidation analysis under existing GAAP will be eliminated, and all reporting entities will now fall within the scope of the Accounting Standards Codification Subtopic 810-10, Consolidation-Overall , unless a specific exception applies. Under this Subtopic, there are only two primary models for determining whether consolidation is appropriate - a voting interest entity model, and a variable interest entity model. The guidance is effective for public business entities for annual periods beginning after December 15, 2015, and interim and annual periods thereafter, with early adoption permitted. The Company is currently evaluating the impact of this guidance. In April 2015, the FASB issued an accounting standards update concerning the presentation of deferred debt issuance costs in an entity's balance sheet. Under this new guidance, which is part of the FASB's initiative to reduce complexity in accounting standards while maintaining or improving the usefulness of the information provided to users of financial statements, debt issuance costs related to a recognized debt liability must be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. In addition, the guidance also requires that the amortization of such costs be reported as interest expense. The guidance is effective for public business entities for annual periods beginning after December 15, 2015, and interim and annual periods thereafter, with early adoption permitted for financial statements that have not been previously issued. This guidance will not have a material impact on the Company's financial condition, results of operations or cash flows. In May 2015, the FASB issued an accounting standards update concerning investments for which management estimates fair value using net asset value per share (or its equivalent) as a practical expedient. Under the guidance, such investments will no longer be reported within the fair value hierarchy. Removing those investments from the fair value hierarchy not only eliminates the diversity in practice resulting from the way in which investments measured at net asset value per share (or its equivalent) with future redemption dates are classified, but also ensures that all investments categorized in the fair value hierarchy are classified using a consistent approach. Investments that calculate net asset value per share (or its equivalent), but for which the practical expedient is not applied, will continue to be included in the fair value hierarchy. A reporting entity should continue to disclose information on investments for which fair value is measured at net asset value (or its equivalent) as a practical expedient to help users understand the nature and risks of the investments and whether the investments, if sold, are probable of being sold at amounts different from net asset value. The guidance is effective for public business entities for annual periods beginning after December 15, 2015 and interim and annual periods thereafter, with early adoption permitted. The Company is currently evaluating the impact of this guidance, but it is not expected to have a material impact on the Company's financial condition, results of operations or cash flows. In May 2015, the FASB issued an accounting standards update concerning the annual disclosure regarding the liability for unpaid claims and claims adjustment expenses for insurance entities. The guidance requires: (1) incurred and paid claims development information by accident year, on a net basis after reinsurance, for the number of years for which claims incurred typically remain outstanding, including the most recent reporting period, which need not exceed 10 years; (2) a reconciliation of incurred and paid claims development information to the aggregate carrying amount of the liability for unpaid claims and claim adjustment expenses, with separate disclosure of reinsurance recoverable on unpaid claims for each period presented in the statement of financial position; (3) for each accident year for which incurred claims development information is presented, the total of incurred but not reported ("IBNR") liabilities plus expected development on reported claims included in the liability for unpaid claims and claims adjustment expenses, accompanied by a description of reserving methodologies; (4) for each accident year for which incurred claims development information is presented, quantitative information about claim frequency (unless it is impracticable to do so) accompanied by a qualitative description of methodologies used for determining claim frequency information; and (5) for all claims, the average annual percentage payout of incurred claims by age for the same number of accident years as the disclosure for IBNR. The guidance recommends that insurance entities aggregate or disaggregate those disclosures so that useful information is not obscured by either the inclusion of a large amount of insignificant detail or the aggregation of items that have significantly different characteristics. The amendments also require insurance entities to disclose information about significant changes in methodologies and assumptions used to calculate the liability for unpaid claims and claim adjustment expenses, including reasons for the change and the effects on the financial statements. Additionally, the amendments require insurance entities to disclose for annual and interim reporting periods a rollforward of the liability for unpaid claims and claims adjustment expenses. Additional disclosures about liabilities for unpaid claims and claim adjustment expenses reported at present value include: (1) for each period presented in the statement of financial position, the aggregate amount of discount for the time value of money deducted to derive the liability for unpaid claims and claim adjustment expenses; (2) for each period presented in the statement of income, the amount of interest accretion recognized; and (3) the line items in the statement of income in which interest accretion is classified. The guidance is effective for public business entities for annual periods beginning after December 15, 2015 and interim periods within annual periods after December 15, 2016. Early adoption is permitted. The Company is currently evaluating the impact of this guidance, but it is not expected to have a material impact on the Company's financial condition, results of operations or cash flows. In September 2015, the FASB issued an accounting standards update concerning the accounting for measurement period adjustments following the completion of a business combination. The measurement period ends as soon as the acquirer receives the information it was seeking about facts and circumstances that existed as of the acquisition date or learns that more information is not obtainable; however, it shall not exceed one year from the acquisition date. Currently under GAAP, during the measurement period the acquirer shall recognize such adjustments to the provisional amounts as if the accounting for the business combination had been completed at the acquisition date, with a corresponding adjustment to goodwill, in the reporting period in which the adjustments are determined. The acquirer shall revise comparative information for prior periods presented in financial statements as needed as a result of the change to the provisional amounts calculated. Under the new guidance, although such adjustments shall still be calculated as if the accounting had been completed at the business combination date, the acquirer should recognize in its current-period earnings the cumulative effect of changes in depreciation, amortization, or other income effects, by line item, related to the periods subsequent to the acquisition date as a result of the adjustments. In addition, entities must present separately on the face of the income statement, or alternatively in the notes to the financial statements, the portion of such current period adjustments that would have been recorded in previous reporting periods, if the adjustments had been recognized at the acquisition date. The guidance is effective for provisional adjustments made by public business entities in annual periods beginning after December 15, 2015 - irrespective of the date of the business combination to which they relate - including interim periods within those fiscal years. Early adoption is permitted for financial statements that have not yet been made available for issuance. To the extent that the Company were to make material measurement period adjustments to provisional amounts recognized as part of the Catlin Acquisition, this could have a material impact on the Company's results of operations during the period in which such adjustments were made. The guidance is not expected to have a material impact on the Company's financial condition or cash flows.

Acquisition and Disposals (Tabl

Acquisition and Disposals (Tables)	9 Months Ended
	Sep. 30, 2015
Acquisition and Disposal [Abstract]
Acquisition consideration	The calculation of the consideration transferred to acquire Catlin Shares is as follows: (In thousands, except per share data) Catlin Shares outstanding as of April 30, 2015 that received share consideration (including the dilutive effect of warrants) 384,118 Exchange ratio per the Implementation Agreement 0.130 XL Share issuance to Catlin shareholders 49,935 Closing price per XL share on April 30, 2015 (1) $ 37.08 XL Share issuance consideration $ 1,851,601 Catlin Shares outstanding as of April 30, 2015 that received cash consideration (including the dilutive effect of warrants) 384,118 Cash price component, per Catlin Share in GBP £ 3.88 Cash consideration, in GBP £ 1,490,377 Foreign exchange rate: GBP/USD on April 30, 2015 $ 1.5349 Cash consideration $ 2,287,579 Total acquisition consideration $ 4,139,180 ____________ (1) The closing market price of XL Shares on the Acquisition Date represents the fair value of XL shares issued as part of the Acquisition Consideration.
Fair value of net assets acquired and liabilities assumed	The following table summarizes the fair values of the assets acquired and liabilities assumed at the Acquisition Date: (U.S. dollars in thousands) ASSETS Fixed maturities, at fair value $ 6,266,489 Short-term investments, at fair value 634,599 Equity investments, at fair value 236,230 Investment in affiliates 216,843 Other investments 386,828 Total investments $ 7,740,989 Cash and cash equivalents (1) 1,267,565 Accrued investment income 35,063 Premiums receivable 2,545,188 Unpaid losses and loss expenses recoverable 1,493,267 Reinsurance balances receivable 299,579 Ceded unearned premiums 1,143,852 Deferred acquisition costs and value of business acquired 679,259 Intangible assets 988,000 Receivable from investments sold 9,633 Other assets 314,168 Total assets $ 16,516,563 LIABILITIES Unpaid losses and loss expenses $ 6,933,144 Unearned premiums 3,742,234 Reinsurance balances payable 1,441,749 Notes payable and debt 82,066 Payable for investments purchased 34,149 Deferred tax liability 94,071 Other liabilities 265,728 Total liabilities $ 12,593,141 Net assets acquired before non-controlling interest $ 3,923,422 Non-controlling interest in equity of consolidated subsidiaries 562,285 Net assets acquired $ 3,361,137 Acquisition Consideration $ 4,139,180 Goodwill $ 778,043 ____________ (1) Includes Restricted Cash
Transaction related costs	As a part of the ongoing integration of Catlin's operations, the Company incurs costs associated with restructuring the systems, processes and workforce. These costs include such items as severance, retention, facilities and consulting and other costs. The Company separately identifies such costs and includes these expenses within Corporate and Other: (U.S. dollars in thousands) Severance related costs Retention and other compensation costs Facilities-related costs Consulting and other Costs incurred in 2015 $ 27,778 $ 16,363 $ 6,689 $ 32,215 2015 payments 14,078 7,343 6,689 23,723 Liabilities at September 30, 2015 $ 13,700 $ 9,020 $ — $ 8,492
Financial results	(U.S. dollars in thousands) May 1, 2015 to September 30, 2015 Total revenues - see comments above $ 1,770,886 Net income (loss) - see comments above $ 65,796
Supplemental pro forma information	The following table presents unaudited pro forma consolidated information for the nine months ended September 30, 2015 and 2014 and assumes the Catlin Acquisition occurred on January 1, 2014. The pro forma financial information is presented for informational purposes only and does not necessarily reflect the results that would have occurred had the acquisition taken place on January 1, 2014, nor is it necessarily indicative of future results. Significant adjustments used to determine pro forma results include amortization of intangible assets and amortization of fair value adjustments discussed above, and the corresponding income tax effects. Non-recurring transaction related costs noted above have been included in the unaudited pro forma results for the nine months ended September 30, 2014 . Unaudited Pro Forma Nine Months Ended September 30, (In thousands, except per share data) 2015 2014 Total revenues $ 7,997,602 $ 8,391,849 Net income attributable to ordinary shareholders 986,918 226,983 Earnings (loss) per ordinary share and ordinary share equivalent – basic 3.24 0.71 Earnings (loss) per ordinary share and ordinary share equivalent – diluted 3.19 0.70
Impact of Life Retro Arrangements	The impact of the Life Retro Arrangements on the Company's results was as follows: Impact of Life Retro Arrangements Three months ended September 30, Nine Months Ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Underwriting profit (loss) (1) $ — $ 3,711 $ 603 $ 3,711 Net investment income - Life Funds Withheld Assets 46,586 56,474 143,869 75,639 Net realized gains (losses) on investments sold - Life Funds Withheld Assets 53,780 2,022 174,555 2,646 Net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets (149 ) — (18,932 ) — OTTI on investments - Life Funds Withheld Assets (2,023 ) (7,494 ) (10,110 ) (16,265 ) Exchange gains (losses) 8,754 2,062 (5,932 ) 2,062 Other income and expenses (121 ) 124 2,354 105 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets (126,140 ) (201,264 ) (116,333 ) (218,810 ) Net income (loss) $ (19,313 ) $ (144,365 ) $ 170,074 $ (150,912 ) Change in net unrealized gains (losses) on investments - Life Funds Withheld Assets, net of tax (33,569 ) 93,921 (317,500 ) 106,218 Change in adjustments related to future policy benefit reserves, net of tax 40,681 51,286 127,365 51,286 Change in cumulative translation adjustment - Life Funds Withheld Assets, net of tax 12,201 2,869 20,664 (2,881 ) Total changes to other comprehensive income as a result of Life Retro Arrangements $ 19,313 $ 148,076 $ (169,471 ) $ 154,623 Comprehensive income (loss) $ — $ 3,711 $ 603 $ 3,711 ____________ (1) The underwriting profit of $0.6 million relates to a premium adjustment during the nine months ended September 30, 2015 relating to the Life Retro Arrangements transaction. Excluding this transaction, the impact to comprehensive income relating to the Life Retro Arrangements was nil for the nine months ended September 30, 2015.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Hierarchy	The following tables set forth the Company’s assets and liabilities that were accounted for at fair value as of September 30, 2015 and December 31, 2014 by level within the fair value hierarchy: September 30, 2015 (U.S. dollars in thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Unobservable Inputs (Level 3) Collateral and Counterparty Netting Balance at Assets Fixed maturities - Available for Sale ("AFS") - Excluding Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ — $ 4,298,723 $ — $ — $ 4,298,723 Corporate - Financials — 3,062,530 10,000 — 3,072,530 Corporate - Non Financials (1) — 6,850,318 5,272 — 6,855,590 Residential mortgage-backed securities – Agency ("RMBS - Agency") — 3,920,607 2,882 — 3,923,489 Residential mortgage-backed securities – Non-Agency ("RMBS - Non-Agency") — 362,965 — — 362,965 Commercial mortgage-backed securities ("CMBS") — 850,084 — — 850,084 Collateralized debt obligations ("CDOs") — 2,500 407,663 — 410,163 Other asset-backed securities (1) — 2,059,478 36,120 — 2,095,598 U.S. States and political subdivisions of the States — 2,648,670 — — 2,648,670 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 5,120,149 — — 5,120,149 Total fixed maturities - AFS - Excluding Funds Withheld Assets, at fair value $ — $ 29,176,024 $ 461,937 $ — $ 29,637,961 Equity securities, at fair value 478,815 490,891 — — 969,706 Short-term investments, at fair value (1)(2) — 546,020 — — 546,020 Total investments AFS - Excluding Funds Withheld Assets $ 478,815 $ 30,212,935 $ 461,937 $ — $ 31,153,687 Fixed maturities - Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ — $ 13,412 $ — $ — $ 13,412 Corporate - Financials — 669,788 — — 669,788 Corporate - Non Financials — 1,480,112 — — 1,480,112 RMBS – Agency — 814 — — 814 RMBS – Non-Agency — 28,833 — — 28,833 CMBS — 141,166 — — 141,166 Other asset-backed securities — 162,871 — — 162,871 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 1,141,365 — — 1,141,365 Total fixed maturities - AFS - Life Funds Withheld Assets, at fair value $ — $ 3,638,361 $ — $ — $ 3,638,361 Total investments - AFS, at fair value $ 478,815 $ 33,851,296 $ 461,937 $ — $ 34,792,048 Fixed maturities - trading securities ("Trading") U.S. Government and Government-Related/Supported $ — $ 4,610 $ — $ — $ 4,610 Corporate - Financials — 219,767 — — 219,767 Corporate - Non Financials — 393,246 — — 393,246 CMBS — 4,982 — — 4,982 Other asset-backed securities — 19,872 — — 19,872 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 342,746 — — 342,746 Total fixed maturities - Trading, at fair value $ — $ 985,223 $ — $ — $ 985,223 Cash equivalents (3) 940,303 455,699 — — 1,396,002 Cash equivalents - Life Funds Withheld Assets (3) 1,440 86,840 — — 88,280 Other investments (4) — 1,051,558 278,222 — 1,329,780 Other assets (5) — 59,231 14,884 (3,900 ) 70,215 Total assets accounted for at fair value $ 1,420,558 $ 36,489,847 $ 755,043 $ (3,900 ) $ 38,661,548 Liabilities Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable) (6) $ — $ 468,187 $ — $ — $ 468,187 Financial instruments sold, but not yet purchased (7) 1,588 693 — — 2,281 Other liabilities (5) — 25,142 24,568 (3,900 ) 45,810 Total liabilities accounted for at fair value $ 1,588 $ 494,022 $ 24,568 $ (3,900 ) $ 516,278 December 31, 2014 (U.S. dollars in thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Unobservable Inputs (Level 3) Collateral and Counterparty Netting Balance at December 31, 2014 Assets Fixed maturities - AFS - Excluding Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ — $ 2,171,953 $ — $ — $ 2,171,953 Corporate - Financials — 2,761,916 — — $ 2,761,916 Corporate - Non Financials (1) — 6,010,563 5,894 — $ 6,016,457 Residential mortgage-backed securities – RMBS - Agency — 3,726,666 1,910 — $ 3,728,576 Residential mortgage-backed securities – RMBS - Non-Agency — 427,351 — — $ 427,351 CMBS — 1,052,544 — — $ 1,052,544 CDOs — 4,076 687,958 — $ 692,034 Other asset-backed securities (1) — 1,060,005 5,288 — $ 1,065,293 U.S. States and political subdivisions of the States — 2,021,272 — — $ 2,021,272 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 4,240,073 — — $ 4,240,073 Total fixed maturities - AFS - Excluding Funds Withheld Assets, at fair value $ — $ 23,476,419 $ 701,050 $ — $ 24,177,469 Equity securities, at fair value 502,284 366,008 — — 868,292 Short-term investments, at fair value (1)(2) — 256,727 — — 256,727 Total investments AFS - Excluding Funds Withheld Assets $ 502,284 $ 24,099,154 $ 701,050 $ — $ 25,302,488 Fixed maturities - Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ — $ 18,724 $ — $ — $ 18,724 Corporate - Financials — 801,019 — — $ 801,019 Corporate - Non Financials — 2,016,961 — — $ 2,016,961 RMBS – Agency — 3,782 — — $ 3,782 RMBS – Non-Agency — 85,335 — — $ 85,335 CMBS — 193,167 — — $ 193,167 Other asset-backed securities — 273,541 — — $ 273,541 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported — 1,789,036 — — $ 1,789,036 Total fixed maturities - AFS - Life Funds Withheld Assets, at fair value $ — $ 5,181,565 $ — $ — $ 5,181,565 Total investments - AFS, at fair value $ 502,284 $ 29,280,719 $ 701,050 $ — $ 30,484,053 Fixed maturities - Trading Corporate - Non Financials — 1,171 — — $ 1,171 Total fixed maturities - Trading, at fair value $ — $ 1,171 $ — $ — $ 1,171 Cash equivalents (3) 1,103,877 397,955 — — $ 1,501,832 Cash equivalents - Life Funds Withheld Assets (3) 460 132,738 — — $ 133,198 Other investments (4) — 708,974 185,083 — $ 894,057 Other assets (5) — 122,996 13,663 (696 ) $ 135,963 Total assets accounted for at fair value $ 1,606,621 $ 30,644,553 $ 899,796 $ (696 ) $ 33,150,274 Liabilities Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable) (6) $ — $ 450,831 $ — $ — $ 450,831 Financial instruments sold, but not yet purchased (7) 4,737 25,669 — — $ 30,406 Other liabilities (5) — 7,757 23,427 (696 ) $ 30,488 Total liabilities accounted for at fair value $ 4,737 $ 484,257 $ 23,427 $ (696 ) $ 511,725 ____________ (1) Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes had a fair value of $74.3 million and $79.9 million and an amortized cost of $64.6 million and $68.4 million as of September 30, 2015 and December 31, 2014 , respectively. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate values of these notes. (2) Short-term investments consist primarily of Corporate securities and U.S. and Non-U.S. Government and Government-Related/Supported securities. (3) Cash equivalents balances subject to fair value measurement include certificates of deposit and money market funds. Operating cash balances are not subject to recurring fair value measurement guidance. (4) The Other investments balance excludes certain structured transactions including certain investments in project finance transactions, and a payment obligation and liquidity financing provided to a structured credit vehicle as a part of a third party medium term note facility. These investments, which totaled $346.4 million as of September 30, 2015 and $354.4 million as of December 31, 2014 , are carried at amortized cost. For further information, see Item 8, Note 8, "Other Investments ," to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2014 . (5) Other assets and other liabilities include derivative instruments. The derivative balances included in each category are reported on a gross basis by level with a netting adjustment presented separately in the Collateral and Counterparty Netting column. The fair values of the individual derivative contracts are reported gross in their respective levels based on the fair value hierarchy. For further details regarding derivative fair values and associated collateral received or paid, see Note 7, "Derivative Instruments ," to the Unaudited Consolidated Financial Statements. (6) Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable) include balances related to the life retrocession embedded derivative, under which all investment results associated with the Life Funds Withheld Assets related to the Life Retro Arrangements described in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary ," accrue to the benefit of GCLR. (7) Financial instruments sold, but not yet purchased, represent "short sales" and are included within "Payable for investments purchased" on the balance sheets.
Level 3 Roll Forward	Level 3 Assets and Liabilities - Three Months Ended September 30, 2015 (U.S. dollars in thousands) Corporate - Financials Corporate - Non-Financials RMBS - Agency RMBS - Non Balance, beginning of period $ 10,000 $ 5,554 $ 3,038 $ — Realized gains (losses) — (45 ) — — Movement in unrealized gains (losses) — (1 ) (2 ) — Purchases and issuances (1) — — — — Sales — — — — Settlements — (236 ) (154 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ 10,000 $ 5,272 $ 2,882 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ (1 ) $ (2 ) $ — Level 3 Assets and Liabilities - Three Months Ended September 30, 2015 (U.S. dollars in thousands) CMBS CDO Other asset- Non-US Sovereign Balance, beginning of period $ — $ 484,171 $ 42,745 $ — Realized gains (losses) — (8,469 ) 553 — Movement in unrealized gains (losses) — 8,994 (976 ) — Purchases and issuances (1) — 2,101 3,334 — Sales — (56,576 ) — — Settlements — (22,558 ) (3,087 ) — Transfers into Level 3 — — — — Transfers out of Level 3 — — (6,449 ) — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 407,663 $ 36,120 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 164 $ (5 ) $ — Level 3 Assets and Liabilities - Three Months Ended September 30, 2015 (U.S. dollars in thousands) Short-term Other investments Derivative Contracts Balance, beginning of period $ — $ 255,672 $ (9,753 ) Realized gains (losses) — 9,185 — Movement in unrealized gains (losses) — (5,567 ) 69 Purchases and issuances (1) — 30,519 — Sales — (1,417 ) Settlements — (10,170 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — Fixed maturities to short-term investments classification change — — — Balance, end of period $ — $ 278,222 $ (9,684 ) Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 3,618 $ 69 ____________ (1) Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ." Level 3 Assets and Liabilities - Three Months Ended September 30, 2014 (U.S. dollars in thousands) Corporate - Financials Corporate - Non-Financials RMBS - Agency RMBS - Non Agency Balance, beginning of period $ — $ 3,933 $ 6,896 $ 11 Realized gains (losses) — 3 (1 ) — Movement in unrealized gains (losses) — 24 (7 ) (1 ) Purchases and issuances (1) — 2,316 120 — Sales — — — — Settlements — — (526 ) — Transfers into Level 3 — 766 — — Transfers out of Level 3 — — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 7,042 $ 6,482 $ 10 Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 27 $ (8 ) $ — Level 3 Assets and Liabilities - Three Months Ended September 30, 2014 (U.S. dollars in thousands) CMBS CDO Other asset- backed securities Non-US Sovereign Government, Provincial, Supranational and Government Related/Supported Balance, beginning of period $ 1,945 $ 732,824 $ 11,704 $ — Realized gains (losses) — 707 3 — Movement in unrealized gains (losses) — 1,591 (113 ) — Purchases and issuances (1) — 82,695 2,182 — Sales — (7,489 ) — — Settlements (569 ) (67,845 ) (1,726 ) — Transfers into Level 3 — — — — Transfers out of Level 3 (1,376 ) — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 742,483 $ 12,050 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 2,297 $ (110 ) $ — Level 3 Assets and Liabilities - Three Months Ended September 30, 2014 (U.S. dollars in thousands) Short-term investments Other investments Derivative Contracts - Net Balance, beginning of period $ — $ 124,475 $ (18,910 ) Realized gains (losses) — 1,850 — Movement in unrealized gains (losses) — 2,790 710 Purchases and issuances (1) — 22,308 — Sales — — — Settlements — (4,888 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — Fixed maturities to short-term investments classification change — — — Balance, end of period $ — $ 146,535 $ (18,200 ) Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 4,639 $ 710 ____________ (1) Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ." Level 3 Assets and Liabilities - Nine Months Ended September 30, 2015 (U.S. dollars in thousands) Corporate - Financials Corporate - Non-Financials RMBS - Agency RMBS - Non Balance, beginning of period $ — $ 5,894 $ 1,910 $ — Realized gains (losses) — (186 ) — — Movement in unrealized gains (losses) — 3 (4 ) — Purchases and issuances (1) 10,000 (123 ) 1,297 — Sales — — — — Settlements — (316 ) (321 ) — Transfers into Level 3 — — — — Transfers out of Level 3 — — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ 10,000 $ 5,272 $ 2,882 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ (137 ) $ (2 ) $ — Level 3 Assets and Liabilities - Nine Months Ended September 30, 2015 (U.S. dollars in thousands) CMBS CDO Other asset- Non-US Sovereign Balance, beginning of period $ — $ 687,958 $ 5,288 $ — Realized gains (losses) — (8,209 ) 644 — Movement in unrealized gains (losses) — 16,994 (966 ) — Purchases and issuances (1) — 14,042 43,962 — Sales — (211,661 ) — — Settlements — (91,461 ) (6,359 ) — Transfers into Level 3 — — — — Transfers out of Level 3 — — (6,449 ) — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 407,663 $ 36,120 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 4,889 $ 95 $ — Level 3 Assets and Liabilities - Nine Months Ended September 30, 2015 (U.S. dollars in thousands) Short-term Other investments Derivative Contracts Balance, beginning of period $ — $ 185,083 $ (9,764 ) Realized gains (losses) — 11,778 — Movement in unrealized gains (losses) — (7,533 ) 80 Purchases and issuances (1) — 103,822 — Sales — (1,417 ) — Settlements — (13,511 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — Fixed maturities to short-term investments classification change — — — Balance, end of period $ — $ 278,222 $ (9,684 ) Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 4,246 $ 80 ____________ (1) Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition " Level 3 Assets and Liabilities - Nine Months Ended September 30, 2014 (U.S. dollars in thousands) Corporate - Financials Corporate - Non-Financials RMBS - Agency RMBS - Non Agency Balance, beginning of period $ — $ 31,573 $ 10,473 $ 9 Realized gains (losses) — 158 5 — Movement in unrealized gains (losses) — (72 ) (20 ) 1 Purchases and issuances (1) — 3,759 120 — Sales — — — — Settlements — (5,513 ) (3,124 ) — Transfers into Level 3 — 766 — — Transfers out of Level 3 — (23,629 ) (972 ) — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 7,042 $ 6,482 $ 10 Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 117 $ (14 ) $ 2 Level 3 Assets and Liabilities - Nine Months Ended September 30, 2014 (U.S. dollars in thousands) CMBS CDO Other asset- backed securities Non-US Sovereign Government, Provincial, Supranational and Government Related/Supported Balance, beginning of period $ 12,533 $ 710,253 $ 11,877 $ — Realized gains (losses) 3 3,163 (17 ) — Movement in unrealized gains (losses) (3 ) 13,604 93 — Purchases and issuances (1) 1,376 185,710 5,182 — Sales — (48,313 ) — — Settlements (12,533 ) (121,934 ) (5,085 ) — Transfers into Level 3 — — — — Transfers out of Level 3 (1,376 ) — — — Fixed maturities to short-term investments classification change — — — — Balance, end of period $ — $ 742,483 $ 12,050 $ — Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 15,513 $ 76 $ — Level 3 Assets and Liabilities - Nine Months Ended September 30, 2014 (U.S. dollars in thousands) Short-term investments Other investments Derivative Contracts - Net Balance, beginning of period $ 2,015 $ 113,472 $ (29,110 ) Realized gains (losses) — 10,541 — Movement in unrealized gains (losses) (15 ) 2,508 10,910 Purchases and issuances (1) — 43,394 — Sales — — — Settlements (2,000 ) (23,380 ) — Transfers into Level 3 — — — Transfers out of Level 3 — — — Fixed maturities to short-term investments classification change — — — Balance, end of period $ — $ 146,535 $ (18,200 ) Movement in total gains (losses) above relating to instruments still held at the reporting date $ — $ 13,048 $ 10,910 ____________ (1) Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition ".
Financial Instruments Not Carried at Fair Value	The following table includes financial instruments for which the carrying value differs from the estimated fair values as of September 30, 2015 and December 31, 2014 . All of these fair value estimates are considered Level 2 fair value measurements. September 30, 2015 December 31, 2014 (U.S. dollars in thousands) Carrying Value Fair Value Carrying Value Fair Value Financial Assets - Other investments, structured transactions $ 346,359 $ 363,251 $ 354,382 $ 371,625 Deposit liabilities $ 1,194,815 $ 1,471,562 $ 1,245,367 $ 1,543,761 Notes payable and debt 2,726,917 2,919,907 1,662,580 1,897,854 Financial Liabilities $ 3,921,732 $ 4,391,469 $ 2,907,947 $ 3,441,615

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Schedule of segment reporting, by segment	The following tables summarize the segment results for the three and nine months ended September 30, 2015 and 2014 : Three Months Ended September 30, 2015 (U.S. dollars in thousands, except ratios) Insurance Reinsurance Total P&C Corporate and Other (1) Total Gross premiums written $ 2,200,196 $ 458,946 $ 2,659,142 $ 80,208 $ 2,739,350 Net premiums written 1,664,562 408,654 2,073,216 17,812 2,091,028 Net premiums earned 1,632,988 772,752 2,405,740 17,812 2,423,552 Net losses and loss expenses (2) 1,037,727 426,558 1,464,285 22,579 1,486,864 Acquisition costs (2) 214,773 189,671 404,444 4,729 409,173 Operating expenses (3) 334,211 88,682 422,893 (26 ) 422,867 Underwriting profit (loss) $ 46,277 $ 67,841 $ 114,118 $ (9,470 ) $ 104,648 Net investment income - excluding Life Funds Withheld Assets (4) 152,738 10,254 162,992 Net investment income - Life Funds Withheld Assets 46,586 46,586 Net results from structured products (5) 3,328 1,109 4,437 — 4,437 Net fee income and other (6) (5,207 ) 533 (4,674 ) 254 (4,420 ) Net realized gains (losses) on investments - excluding Life Funds Withheld Assets (197 ) (4 ) (201 ) Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets — 51,608 51,608 Net realized and unrealized gains (losses) on derivative instruments — (7,903 ) (7,903 ) Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets — (126,140 ) (126,140 ) Net income (loss) from investment fund affiliates and operating affiliates (7) — 4,481 4,481 Exchange (gains) losses — 11,661 11,661 Corporate operating expenses — 135,500 135,500 Contribution from P&C and Corporate and Other 266,422 (177,495 ) 88,927 Interest expense (8) 40,798 40,798 Non-controlling interests 57,889 57,889 Income tax expense (37,042 ) (37,042 ) Net income (loss) attributable to ordinary shareholders $ 27,282 Ratios – P&C operations: (9) Loss and loss expense ratio 63.5 % 55.2 % 60.9 % Underwriting expense ratio 33.7 % 36.0 % 34.4 % Combined ratio 97.2 % 91.2 % 95.3 % ____________ (1) Corporate and Other includes other items of our revenues and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations. (2) The Company has reflected the amortization of certain fair value adjustments recorded in conjunction with the Catlin Acquisition within the respective segments. (3) Operating expenses of the segments exclude Corporate operating expenses, shown separately. (4) Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products. (5) The net results from P&C structured products include net investment income and interest expense of $15.6 million and $11.1 million , respectively. (6) Net fee income and other includes operating expenses from the Company's loss prevention consulting services business. (7) The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one -month and three -month lag, respectively. (8) Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments. (9) Ratios are based on net premiums earned from P&C operations. Three Months Ended September 30, 2014 (U.S. dollars in thousands, except ratios) Insurance Reinsurance Total P&C Corporate and Other (1) Total Gross premiums written $ 1,324,418 $ 276,284 $ 1,600,702 $ 83,496 $ 1,684,198 Net premiums written 956,185 258,061 1,214,246 19,739 1,233,985 Net premiums earned 1,018,416 435,257 1,453,673 19,739 1,473,412 Net losses and loss expenses 650,256 209,332 859,588 20,101 879,689 Acquisition costs 95,992 84,800 180,792 2,090 182,882 Operating expenses (2) 218,281 50,637 268,918 2,785 271,703 Underwriting profit (loss) $ 53,887 $ 90,488 $ 144,375 $ (5,237 ) $ 139,138 Net investment income - excluding Life Funds Withheld Assets (3) 141,575 11,552 153,127 Net investment income - Life Funds Withheld Assets 56,474 56,474 Net results from structured products (4) 3,571 1,720 5,291 — 5,291 Net fee income and other (5) (3,826 ) 601 (3,225 ) 167 (3,058 ) Net realized gains (losses) on investments - excluding Life Funds Withheld Assets 9,418 395 9,813 Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets — (5,472 ) (5,472 ) Net realized and unrealized gains (losses) on derivative instruments — 5,131 5,131 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets — (201,264 ) (201,264 ) Net income (loss) from investment fund affiliates and operating affiliates (6) — 44,521 44,521 Exchange (gains) losses — (23,348 ) (23,348 ) Corporate operating expenses — 55,322 55,322 Contribution from P&C and Corporate and Other 297,434 (125,707 ) 171,727 Interest expense (7) 31,703 31,703 Non-controlling interests 37,583 37,583 Income tax expense 30,057 30,057 Net income (loss) attributable to ordinary shareholders $ 72,384 Ratios – P&C operations: (8) Loss and loss expense ratio 63.8 % 48.1 % 59.1 % Underwriting expense ratio 30.9 % 31.1 % 31.0 % Combined ratio 94.7 % 79.2 % 90.1 % ____________ (1) Corporate and Other includes other items of our revenue and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations. (2) Operating expenses of the segments exclude Corporate operating expenses, shown separately. (3) Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products. (4) The net results from P&C structured products include net investment income and interest credit of $16.8 million and $11.1 million , respectively. (5) Net fee income and other includes operating expenses from the Company's loss prevention consulting services business. (6) The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one -month and three -month lag, respectively. (7) Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments. (8) Ratios are based on net premiums earned from P&C operations. Nine Months Ended September 30, 2015 (U.S. dollars in thousands, except ratios) Insurance Reinsurance Total P&C Corporate and Other (1) Total Gross premiums written $ 6,074,387 $ 2,066,856 $ 8,141,243 $ 234,602 $ 8,375,845 Net premiums written 4,155,442 1,854,590 6,010,032 50,576 6,060,608 Net premiums earned 4,008,200 1,780,829 5,789,029 50,576 5,839,605 Net losses and loss expenses (2) 2,551,044 834,263 3,385,307 64,047 3,449,354 Acquisition costs (2) 476,876 419,380 896,256 8,230 904,486 Operating expenses (3) 834,829 202,904 1,037,733 846 1,038,579 Underwriting profit (loss) $ 145,451 $ 324,282 $ 469,733 $ (22,547 ) $ 447,186 Net investment income - excluding Life Funds Withheld Assets (4) 435,007 31,295 466,302 Net investment income - Life Funds Withheld Assets 143,869 143,869 Net results from structured products (5) 9,634 5,085 14,719 — 14,719 Net fee income and other (6) (14,705 ) 1,981 (12,724 ) 432 (12,292 ) Net realized gains (losses) on investments - excluding Life Funds Withheld Assets 9,833 (1,081 ) 8,752 Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets — 145,513 145,513 Net realized and unrealized gains (losses) on derivative instruments — 57,127 57,127 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets — (116,333 ) (116,333 ) Net income (loss) from investment fund affiliates and operating affiliates (7) — 103,317 103,317 Gain on sale of operating affiliate 340,407 340,407 Exchange (gains) losses — 49,425 49,425 Corporate operating expenses — 328,930 328,930 Contribution from P&C and Corporate and Other 916,568 303,644 1,220,212 Interest expense (8) 121,317 121,317 Non-controlling interests 100,158 100,158 Income tax expense 20,135 20,135 Net income (loss) attributable to ordinary shareholders $ 978,602 Ratios – P&C operations: (9) Loss and loss expense ratio 63.6 % 46.8 % 58.5 % Underwriting expense ratio 32.8 % 35.0 % 33.4 % Combined ratio 96.4 % 81.8 % 91.9 % ____________ (1) Corporate and Other includes other items of our revenue and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations. (2) The Company has reflected the amortization of certain fair value adjustments recorded in conjunction with the Catlin Acquisition within the respective segments. (3) Operating expenses of the segments exclude Corporate operating expenses, shown separately. (4) Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products. (5) The net results from P&C structured products include net investment income and interest expense of $46.7 million and $31.7 million , respectively. (6) Net fee income and other includes operating expenses from the Company's loss prevention consulting services business. (7) The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one -month and three -month lag, respectively. (8) Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments. (9) Ratios are based on net premiums earned from P&C operations. Nine Months Ended September 30, 2014 (U.S. dollars in thousands, except ratios) Insurance Reinsurance Total P&C Corporate Total Gross premiums written $ 4,513,749 $ 1,627,121 $ 6,140,870 $ 254,503 $ 6,395,373 Net premiums written 3,080,432 1,486,680 4,567,112 154,568 4,721,680 Net premiums earned 3,014,846 1,289,431 4,304,277 154,568 4,458,845 Net losses and loss expenses 1,917,076 601,897 2,518,973 218,987 2,737,960 Acquisition costs 300,855 252,909 553,764 13,151 566,915 Operating expenses (2) 635,264 139,080 774,344 8,182 782,526 Underwriting profit (loss) $ 161,651 $ 295,545 $ 457,196 $ (85,752 ) $ 371,444 Net investment income - excluding Life Funds Withheld Assets (3) 429,657 134,562 564,219 Net investment income - Life Funds Withheld Assets 75,639 75,639 Net results from structured products (4) 40,106 8,023 48,129 — 48,129 Net fee income and other (5) (8,605 ) 1,938 (6,667 ) 257 (6,410 ) Loss on sale of life reinsurance subsidiary — 666,423 666,423 Net realized gains (losses) on investments - excluding Life Funds Withheld Assets 105,589 4,297 109,886 Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets — (13,619 ) (13,619 ) Net realized and unrealized gains (losses) on derivative instruments — 18,540 18,540 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets — (218,810 ) (218,810 ) Net income (loss) from investment fund affiliates and operating affiliates (6) — 169,530 169,530 Exchange (gains) losses — 8,234 8,234 Corporate operating expenses — 163,155 163,155 Contribution from P&C and Corporate and Other 1,033,904 (753,168 ) 280,736 Interest expense (7) 96,147 96,147 Non-controlling interests 77,024 77,024 Income tax expense 58,724 58,724 Net income (loss) attributable to ordinary shareholders $ 48,841 Ratios – P&C operations: (8) Loss and loss expense ratio 63.6 % 46.7 % 58.5 % Underwriting expense ratio 31.0 % 30.4 % 30.9 % Combined ratio 94.6 % 77.1 % 89.4 % ____________ (1) Corporate and Other includes other items of our revenue and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations. (2) Operating expenses of the segments exclude Corporate operating expenses, shown separately. (3) Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products. (4) The net results from P&C structured products include net investment income and interest credit of $52.5 million and $3.7 million , respectively. (5) Net fee income and other includes operating expenses from the Company's loss prevention consulting services business. (6) The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one -month and three -month lag, respectively. (7) Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments. (8) Ratios are based on net premiums earned from P&C operations.
Schedule of net premiums earned by line of business	The following tables summarize the Company’s net premiums earned by line of business for the three and nine months ended September 30, 2015 and 2014 : Three Months Ended September 30, 2015 (U.S. dollars in thousands) Insurance Reinsurance Corporate Total P&C Operations: Professional $ 299,639 $ 46,877 $ — $ 346,516 Casualty 473,777 141,135 — 614,912 Property catastrophe — 205,337 — 205,337 Property 320,878 271,297 — 592,175 Marine, energy, aviation and satellite — 36,345 — 36,345 Specialty 462,029 — — 462,029 Other (1) 76,665 71,761 — 148,426 Total P&C Operations $ 1,632,988 $ 772,752 $ — $ 2,405,740 Corporate and Other: Run-off Life operations - Annuity $ — $ — $ — $ — Run-off Life operations - Other Life — — 17,812 17,812 Total Corporate and Other $ — $ — $ 17,812 $ 17,812 Total $ 1,632,988 $ 772,752 $ 17,812 $ 2,423,552 Three Months Ended September 30, 2014 (U.S. dollars in thousands) Insurance Reinsurance Corporate and Other Total P&C Operations: Professional $ 269,275 $ 45,221 $ — $ 314,496 Casualty 358,505 66,638 — 425,143 Property catastrophe — 103,813 — 103,813 Property 139,663 155,415 — 295,078 Marine, energy, aviation and satellite — 30,511 — 30,511 Specialty 186,360 — — 186,360 Other (1) 64,613 33,659 — 98,272 Total P&C Operations $ 1,018,416 $ 435,257 $ — $ 1,453,673 Corporate and Other: Run-off Life operations - Annuity $ — $ — $ 2 $ 2 Run-off Life operations - Other Life — — 19,737 19,737 Total Corporate and Other $ — $ — $ 19,739 $ 19,739 Total $ 1,018,416 $ 435,257 $ 19,739 $ 1,473,412 ____________ (1) Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines. Nine Months Ended September 30, 2015 (U.S. dollars in thousands) Insurance Reinsurance Corporate Total P&C Operations: Professional $ 852,398 $ 125,110 $ — $ 977,508 Casualty 1,203,584 325,130 — 1,528,714 Property catastrophe — 462,862 — 462,862 Property 708,275 634,419 — 1,342,694 Marine, energy, aviation and satellite — 86,969 — 86,969 Specialty 1,014,147 — — 1,014,147 Other (1) 229,796 146,339 — 376,135 Total P&C Operations $ 4,008,200 $ 1,780,829 $ — $ 5,789,029 Corporate and Other: Run-off Life operations - Annuity $ — $ — $ — $ — Run-off Life operations - Other Life — — 50,576 50,576 Total Corporate and Other $ — $ — $ 50,576 $ 50,576 Total $ 4,008,200 $ 1,780,829 $ 50,576 $ 5,839,605 Nine Months Ended September 30, 2014 (U.S. dollars in thousands) Insurance Reinsurance Corporate Total P&C Operations: Professional $ 812,211 $ 139,564 $ — $ 951,775 Casualty 1,061,499 226,288 — 1,287,787 Property catastrophe — 324,812 — 324,812 Property 422,270 432,991 — 855,261 Marine, energy, aviation and satellite — 75,090 — 75,090 Specialty 543,217 — — 543,217 Other (1) 175,649 90,686 — 266,335 Total P&C Operations $ 3,014,846 $ 1,289,431 $ — $ 4,304,277 Corporate and Other: Run-off Life operations - Annuity $ — $ — $ 53,363 $ 53,363 Run-off Life operations - Other Life — — 101,205 101,205 Total Corporate and Other $ — $ — $ 154,568 $ 154,568 Total $ 3,014,846 $ 1,289,431 $ 154,568 $ 4,458,845 ____________ (1) Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Amortized cost and fair value summary	The cost (amortized cost for fixed maturities and short-term investments), fair value, gross unrealized gains and gross unrealized (losses), including non-credit related OTTI recorded in accumulated other comprehensive income ("AOCI"), of the Company’s AFS investments as of September 30, 2015 and December 31, 2014 , were as follows: September 30, 2015 (U.S. dollars in thousands) Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Non-credit Related OTTI (1) Fixed maturities - AFS - Excluding Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ 4,241,444 $ 72,193 $ (14,914 ) $ 4,298,723 $ — Corporate - Financials 3,029,683 60,655 (17,808 ) 3,072,530 — Corporate - Non Financials (2) 6,735,784 191,026 (71,220 ) 6,855,590 (3,309 ) RMBS – Agency 3,831,823 100,257 (8,591 ) 3,923,489 — RMBS – Non-Agency 351,793 27,528 (16,356 ) 362,965 (55,474 ) CMBS 837,416 17,642 (4,974 ) 850,084 (1,210 ) CDOs 419,019 1,486 (10,342 ) 410,163 (1,460 ) Other asset-backed securities (2) 2,072,017 34,317 (10,736 ) 2,095,598 (1,351 ) U.S. States and political subdivisions of the States 2,536,974 118,345 (6,649 ) 2,648,670 — Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 5,088,447 113,073 (81,371 ) 5,120,149 — Total fixed maturities - AFS - Excluding Life Funds Withheld Assets $ 29,144,400 $ 736,522 $ (242,961 ) $ 29,637,961 $ (62,804 ) Total short-term investments - Excluding Life Funds Withheld Assets $ 545,979 $ 1,589 $ (1,548 ) $ 546,020 $ — Total equity securities - Excluding Life Funds Withheld Assets $ 984,192 $ 66,786 $ (81,272 ) $ 969,706 $ — Total investments - AFS - Excluding Life Funds Withheld Assets $ 30,674,571 $ 804,897 $ (325,781 ) $ 31,153,687 $ (62,804 ) Fixed maturities - AFS - Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ 10,998 $ 2,414 $ — $ 13,412 $ — Corporate - Financials 596,259 73,529 — 669,788 — Corporate - Non Financials 1,273,946 206,166 — 1,480,112 — RMBS – Agency 652 162 — 814 — RMBS – Non-Agency 25,341 3,492 — 28,833 — CMBS 121,266 19,900 — 141,166 — Other asset-backed securities 141,774 21,097 — 162,871 — Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 892,383 248,982 — 1,141,365 — Total fixed maturities - AFS - Life Funds Withheld Assets $ 3,062,619 $ 575,742 $ — $ 3,638,361 $ — Total investments - AFS $ 33,737,190 $ 1,380,639 $ (325,781 ) $ 34,792,048 $ (62,804 ) Fixed maturities - Trading - Life Funds Withheld Assets Amortized Cost Fair Value U.S. Government and Government-Related/Supported $ 4,614 $ 4,610 Corporate - Financials 228,026 219,767 Corporate - Non Financials 409,745 393,246 CMBS 5,002 4,982 Other asset-backed securities 20,119 19,872 Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 337,249 342,746 Total investments - Trading - Life Funds Withheld Assets $ 1,004,755 $ 985,223 ___________ (1) Represents the non-credit component of OTTI losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the date an impairment was recorded. (2) Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $74.3 million and an amortized cost of $64.6 million . These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes. December 31, 2014 (U.S. dollars in thousands) Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Non-credit Related OTTI (1) Fixed maturities - AFS - Excluding Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ 2,100,851 $ 77,889 $ (6,787 ) $ 2,171,953 $ — Corporate - Financials 2,687,797 87,058 (12,939 ) 2,761,916 — Corporate - Non Financials (2) 5,774,333 278,747 (36,623 ) 6,016,457 (3,309 ) RMBS – Agency 3,625,171 114,188 (10,783 ) 3,728,576 — RMBS – Non-Agency 404,398 41,108 (18,155 ) 427,351 (67,918 ) CMBS 1,033,819 23,987 (5,262 ) 1,052,544 (2,033 ) CDOs 717,544 1,659 (27,169 ) 692,034 (1,663 ) Other asset-backed securities (2) 1,028,528 42,810 (6,045 ) 1,065,293 (1,797 ) U.S. States and political subdivisions of the States 1,892,566 129,910 (1,204 ) 2,021,272 — Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 4,162,425 139,484 (61,836 ) 4,240,073 — Total fixed maturities - AFS - Excluding Life Funds Withheld Assets $ 23,427,432 $ 936,840 $ (186,803 ) $ 24,177,469 $ (76,720 ) Total short-term investments - Excluding Life Funds Withheld Assets $ 257,221 $ 49 $ (543 ) $ 256,727 $ — Total equity securities - Excluding Life Funds Withheld Assets $ 763,833 $ 130,689 $ (26,230 ) $ 868,292 $ — Total investments - AFS - Excluding Life Funds Withheld Assets $ 24,448,486 $ 1,067,578 $ (213,576 ) $ 25,302,488 $ (76,720 ) Fixed maturities - AFS - Life Funds Withheld Assets U.S. Government and Government-Related/Supported $ 14,866 $ 3,858 $ — $ 18,724 $ — Corporate - Financials 701,587 99,432 — 801,019 — Corporate - Non Financials 1,706,262 310,699 — 2,016,961 — RMBS – Agency 3,301 481 — 3,782 — RMBS – Non-Agency 71,075 14,260 — 85,335 — CMBS 168,886 24,281 — 193,167 — Other asset-backed securities 238,168 35,373 — 273,541 — Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 1,397,194 391,842 — 1,789,036 — Total fixed maturities - AFS - Life Funds Withheld Assets $ 4,301,339 $ 880,226 $ — $ 5,181,565 $ — Total investments - AFS $ 28,749,825 $ 1,947,804 $ (213,576 ) $ 30,484,053 $ (76,720 ) Fixed maturities - Trading - Life Funds Withheld Assets Amortized Cost Fair Value Corporate - Non Financials $ 1,180 $ 1,171 Total investments - Trading - Life Funds Withheld Assets $ 1,180 $ 1,171 ____________ (1) Represents the non-credit component of OTTI losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the date an impairment was recorded. (2) Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $79.9 million and an amortized cost of $68.4 million . These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes.
Contractual maturities summary	The contractual maturities of AFS fixed income securities at September 30, 2015 and December 31, 2014 are shown below. Actual 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, 2015 December 31, 2014 (U.S. dollars in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Fixed maturities - AFS - Excluding Life Funds Withheld Assets Due less than one year $ 2,235,684 $ 2,240,138 $ 1,972,224 $ 1,980,429 Due after 1 through 5 years 12,528,098 12,699,855 8,919,037 9,113,651 Due after 5 through 10 years 5,429,115 5,518,600 4,232,396 4,412,569 Due after 10 years 1,439,435 1,537,069 1,494,315 1,705,022 $ 21,632,332 $ 21,995,662 $ 16,617,972 $ 17,211,671 RMBS – Agency 3,831,823 3,923,489 3,625,171 3,728,576 RMBS – Non-Agency 351,793 362,965 404,398 427,351 CMBS 837,416 850,084 1,033,819 1,052,544 CDOs 419,019 410,163 717,544 692,034 Other asset-backed securities 2,072,017 2,095,598 1,028,528 1,065,293 Total mortgage and asset-backed securities $ 7,512,068 $ 7,642,299 $ 6,809,460 $ 6,965,798 Total fixed maturities - AFS - Excluding Life Funds Withheld Assets $ 29,144,400 $ 29,637,961 $ 23,427,432 $ 24,177,469 Fixed maturities - AFS - Life Funds Withheld Assets Due less than one year $ 93,671 $ 104,481 $ 117,048 $ 125,326 Due after 1 through 5 years 441,114 472,560 638,526 685,787 Due after 5 through 10 years 585,388 671,738 1,004,698 1,165,348 Due after 10 years 1,653,413 2,055,898 2,059,637 2,649,279 $ 2,773,586 $ 3,304,677 $ 3,819,909 $ 4,625,740 RMBS – Agency 652 814 3,301 3,782 RMBS – Non-Agency 25,341 28,833 71,075 85,335 CMBS 121,266 141,166 168,886 193,167 Other asset-backed securities 141,774 162,871 238,168 273,541 Total mortgage and asset-backed securities $ 289,033 $ 333,684 $ 481,430 $ 555,825 Total fixed maturities - AFS - Life Funds Withheld Assets $ 3,062,619 $ 3,638,361 $ 4,301,339 $ 5,181,565 Total fixed maturities - AFS $ 32,207,019 $ 33,276,322 $ 27,728,771 $ 29,359,034 Fixed maturities - Trading - Life Funds Withheld Assets Due less than one year $ 71,135 $ 71,139 $ — $ — Due after 1 through 5 years 239,984 233,244 — — Due after 5 through 10 years 178,020 176,077 1,180 1,171 Due after 10 years 490,495 479,909 — — $ 979,634 $ 960,369 $ 1,180 $ 1,171 CMBS 5,002 4,982 — — Other asset-backed securities 20,119 19,872 — — Total mortgage and asset-backed securities $ 25,121 $ 24,854 $ — $ — Total fixed maturities - Trading - Life Funds Withheld Assets $ 1,004,755 $ 985,223 $ 1,180 $ 1,171
Summary of unrealized losses	The following is an analysis of how long the AFS securities as of September 30, 2015 and December 31, 2014 had been in a continual unrealized loss position: Less than 12 months Equal to or greater than 12 months September 30, 2015 (U.S. dollars in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturities and short-term investments - AFS U.S. Government and Government-Related/Supported $ 1,257,855 $ (10,402 ) $ 89,971 $ (4,524 ) Corporate – Financials 862,043 (10,486 ) 83,008 (7,327 ) Corporate – Non Financials 2,181,253 (51,087 ) 218,856 (21,219 ) RMBS – Agency 590,089 (3,386 ) 237,798 (5,205 ) RMBS – Non-Agency 28,054 (1,022 ) 206,549 (15,334 ) CMBS 250,635 (2,361 ) 87,257 (2,613 ) CDOs 118,002 (286 ) 194,633 (10,056 ) Other asset-backed securities 639,048 (4,403 ) 57,445 (6,342 ) U.S. States and political subdivisions of the States 444,195 (5,520 ) 17,840 (1,131 ) Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 1,379,798 (47,122 ) 454,537 (34,683 ) Total fixed maturities and short-term investments - AFS $ 7,750,972 $ (136,075 ) $ 1,647,894 $ (108,434 ) Total equity securities $ 524,692 $ (81,272 ) $ — $ — Less than 12 months Equal to or greater than 12 months December 31, 2014 (U.S. dollars in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturities and short-term investments - AFS U.S. Government and Government-Related/Supported $ 251,091 $ (1,196 ) $ 342,890 $ (5,603 ) Corporate – Financials 387,619 (5,858 ) 105,155 (7,097 ) Corporate – Non Financials 949,851 (28,023 ) 319,066 (8,657 ) RMBS – Agency 134,535 (220 ) 512,652 (10,563 ) RMBS – Non-Agency 45,378 (1,358 ) 202,700 (16,797 ) CMBS 78,356 (385 ) 169,065 (4,877 ) CDOs 249,803 (2,666 ) 414,516 (24,503 ) Other asset-backed securities 143,044 (2,813 ) 57,544 (3,232 ) U.S. States and political subdivisions of the States 32,187 (210 ) 63,695 (994 ) Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported 624,346 (19,043 ) 558,422 (43,251 ) Total fixed maturities and short-term investments - AFS $ 2,896,210 $ (61,772 ) $ 2,745,705 $ (125,574 ) Total equity securities $ 191,193 $ (26,230 ) $ — $ —
Analysis of net realized gains (losses) on investments	The following represents an analysis of net realized gains (losses) on investments: Net Realized Gains (Losses) on Investments Three months ended September 30, Nine months ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Net realized gains (losses) on investments - excluding Life Funds Withheld Assets: Gross realized gains $ 88,224 $ 37,875 $ 199,070 $ 208,035 Gross realized losses on investments sold (45,711 ) (26,918 ) (120,440 ) (68,662 ) OTTI on investments, net of amounts transferred to other comprehensive income (42,714 ) (1,144 ) (69,878 ) (29,487 ) $ (201 ) $ 9,813 $ 8,752 $ 109,886 Net realized gains (losses) on investments and net unrealized gains (losses) on investments, Trading - Life Funds Withheld Assets: Gross realized gains $ 60,643 $ 4,511 $ 198,412 $ 5,135 Gross realized losses on investments sold (6,863 ) (2,489 ) (23,857 ) (2,489 ) OTTI on investments, net of amounts transferred to other comprehensive income (2,023 ) (7,494 ) (10,110 ) (16,265 ) Net unrealized gains (losses) on trading securities $ (149 ) $ — $ (18,932 ) $ — $ 51,608 $ (5,472 ) $ 145,513 $ (13,619 ) Total net realized gains (losses) on investments $ 51,407 $ 4,341 $ 154,265 $ 96,267
Credit loss impairments on fixed inmcome securities rollforward	The following table sets forth the amount of credit loss impairments on fixed income securities for which a portion of the OTTI loss was recognized in OCI, held by the Company as of the dates or for the periods indicated and the corresponding changes in such amounts. Credit Loss Impairments Three months ended September 30, Nine months ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Opening balance as of beginning of indicated period $ 94,219 $ 165,876 $ 131,942 $ 174,805 Credit loss impairment recognized in the current period on securities not previously impaired 2,004 93 9,565 134 Credit loss impairments previously recognized on securities that matured, paid down, prepaid or were sold during the period (1,531 ) (1,840 ) (38,564 ) (10,042 ) Credit loss impairments previously recognized on securities impaired to fair value during the period — — (2,629 ) — Additional credit loss impairments recognized in the current period on securities previously impaired 945 729 1,331 3,882 Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected (2,165 ) (2,471 ) (8,173 ) (6,392 ) Balance as of September 30, $ 93,472 $ 162,387 $ 93,472 $ 162,387

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of location and gross amounts of derivative fair values	The following table summarizes information on the location and gross amounts of derivative fair values contained in the consolidated balance sheets as of September 30, 2015 and December 31, 2014 : September 30, 2015 December 31, 2014 (U.S. dollars in thousands) Asset Derivative Notional Amount Asset Derivative Fair Value (1) Liability Derivative Notional Amount Liability Derivative Fair Value (1) Asset Derivative Notional Amount Asset Derivative Fair Value (1) Liability Derivative Notional Amount Liability Derivative Fair Value (1) Derivatives designated as hedging instruments: Foreign exchange contracts $ 1,391,228 $ 48,774 $ 870,480 $ 20,415 $ 2,300,609 $ 121,862 $ 302,211 $ 2,936 Total derivatives designated as hedging instruments $ 1,391,228 $ 48,774 $ 870,480 $ 20,415 $ 2,300,609 $ 121,862 $ 302,211 $ 2,936 Derivatives not designated as hedging instruments: Investment Related Derivatives: Interest rate exposure $ 21,166 $ 201 $ 3,222 $ 74 $ 394,597 $ 206 $ 20,782 $ 51 Foreign exchange exposure 377,256 4,767 68,578 872 7,385 403 207,182 4,442 Credit exposure 34,273 729 46,304 12,196 2,408 165 14,270 9,836 Financial market exposure 32,340 3,827 40,898 1,410 46,145 360 33,670 34 Other Non-Investment Derivatives: Foreign exchange contracts 72,634 933 — — — — 81,194 282 Credit exposure 30,075 141 — — 31,060 60 — — Guaranteed minimum income benefit contract 48,558 14,743 48,558 14,743 46,249 13,603 46,249 13,603 Modified coinsurance funds withheld contracts (2) 60,792 — 4,798,271 — 64,947 — 5,401,278 — Total derivatives not designated as hedging instruments $ 677,094 $ 25,341 $ 5,005,831 $ 29,295 $ 592,791 $ 14,797 $ 5,804,625 $ 28,248 ____________ (1) Derivative instruments in an asset or liability position are included within Other assets or Other liabilities, respectively, in the balance sheets on a net basis where the Company has both a legal right of offset and the intention to settle the contracts on a net basis. (2) The fair value movements in derivative assets and liabilities relating to modified coinsurance funds withheld contracts are included within the associated asset or liability at each period end on the face of the balance sheets. Notional amounts associated with reinsurance agreements under which the Company assumes reinsurance risk are recorded as asset derivative notional amounts. Notional amounts associated with the Life Retro Arrangements under which the Company cedes reinsurance risk are recorded as liability derivative notional amounts. Included in the liability derivative notional amount as of September 30, 2015 is the cumulative net realized and unrealized loss on life retrocession embedded derivative of $468.2 million .
Summary of gross and net amounts of derivative fair values and associated collateral received or paid	The following table summarizes information on the gross and net amounts of derivative fair values and associated collateral received related to derivative assets, or collateral provided related to derivative liabilities, reported in other assets and or other liabilities within our consolidated balance sheets as of September 30, 2015 and December 31, 2014 : Gross Amounts Not Offset in the Balance Sheets September 30, 2015 (U.S. dollars in thousands) Gross Amounts Recognized in the Balance Sheets Gross Amounts Offset in the Balance Sheets Net Amounts in the Balance Sheets Financial Instruments Cash Collateral Net Amounts Derivative Assets $ 74,115 $ 3,900 $ 70,215 $ — $ 24,000 $ 46,215 Derivative Liabilities $ 49,710 $ 3,900 $ 45,810 $ — $ — $ 45,810 December 31, 2014 (U.S. dollars in thousands) Derivative Assets $ 136,659 $ 696 $ 135,963 $ — $ 78,580 $ 57,383 Derivative Liabilities $ 31,184 $ 696 $ 30,488 $ — $ — $ 30,488
Gain (loss) recognized in income attributable to risk of hedged items	The following table provides the total impact on earnings relating to derivative instruments formally designated as fair value hedges along with the impacts of the related hedged items for the nine months ended September 30, 2014: Hedged Items - Amount of Gain/(Loss) Recognized in Income Attributable to Risk Derivatives Designated as Fair Value Hedges: (U.S. dollars in thousands) Gain/(Loss) Recognized in Income on Derivative Fixed Maturity Investments Ineffective Portion of Hedging Relationship - Gain/(Loss) Interest rate exposure $ — Foreign exchange exposure (15,663 ) Total $ (15,663 ) $ 15,407 $ (256 )
Summary of fair value hedges that have been settled and their impact on results	A summary of the fair value hedges that have been settled and their impact on results during the indicated periods as well as the remaining balance of fair value hedges and average years remaining to maturity as of September 30, 2015 and 2014 are shown below: Settlement of Fair Value Hedges - Summary Fair Value Hedges - Notes Fair Value Hedges - Deposit Liabilities (U.S. dollars in thousands) 2015 2014 2015 2014 Cumulative reduction to interest expense $ — $ 21,624 $ 101,461 $ 93,042 Remaining balance $ — $ — $ 131,734 $ 140,153 Weighted average years remaining to maturity 0.0 0.0 22.0 23.6
Summary of hedges of net investment in foreign operation	The following table provides the weighted average U.S. dollar equivalent of foreign denominated net assets that were hedged and the resulting derivative gain (loss) that was recorded in the foreign currency translation adjustment, net of tax, account within AOCI for the three and nine months ended September 30, 2015 and 2014 : Derivative Instruments Designated as Hedges of the Net Investment in a Foreign Operation - Summary Three months ended September 30, Nine months ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Weighted average of U.S. dollar equivalent of foreign denominated net assets $ 2,299,875 $ 2,052,469 $ 1,581,470 $ 2,336,671 Derivative gains (losses) (1) $ 29,943 $ 64,593 $ 66,215 $ 63,383 ____________ (1) Derivative gains (losses) from derivative instruments designated as hedges of the net investment in a foreign operation are recorded in the cumulative translation adjustment account within AOCI for each period.
Summary of net realized and unrealized gains (losses) on derivative instruments	The following table provides the total impact on earnings relating to derivative instruments not formally designated as hedging instruments under authoritative accounting guidance and from the ineffective portion of fair value hedges. The impacts are all recorded through Net realized and unrealized gains (losses) on derivatives in the income statement for the three and nine months ended September 30, 2015 and 2014 : Net Realized and Unrealized Gains (Losses) on Derivative Instruments Three months ended September 30, Nine months ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Investment Related Derivatives: Interest rate exposure $ (5,120 ) $ 3,987 $ (2,046 ) $ 13,313 Foreign exchange exposure (146 ) (576 ) (1,026 ) 1,222 Credit exposure 1,684 384 1,380 391 Financial market exposure (4,309 ) (912 ) (2,913 ) 2,467 Financial Operations Derivatives: Credit exposure — 915 — (3,438 ) Other Non-Investment Derivatives: Foreign exchange contracts 4,063 — 61,494 — Credit exposure (327 ) — 1,151 — Guaranteed minimum income benefit contract — — — 2,257 Modified coinsurance funds withheld contract (3,748 ) 1,333 (913 ) 2,584 Total gain (loss) recognized in income from derivatives not designated as hedging instruments $ (7,903 ) $ 5,131 $ 57,127 $ 18,796 Amount of gain (loss) recognized in income from ineffective portion of fair value hedges — — — (256 ) Net realized and unrealized gains (losses) on derivative instruments $ (7,903 ) $ 5,131 $ 57,127 $ 18,540 Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets $ (126,140 ) $ (201,264 ) $ (116,333 ) $ (218,810 )
Components of life retrocession embedded derivatives	The change in the value of the life retrocession embedded derivative includes the interest income, realized and unrealized gains and losses on Life Funds Withheld Assets and certain related expenses subsequent to May 30, 2014 as follows: Components of Life Retrocession Embedded Derivative and Derivative Instruments - Life Funds Withheld Assets: Three months ended September 30, Nine Months Ended September 30, (U.S. dollars in thousands) 2015 2014 2015 2014 Interest income - Life Funds Withheld Assets $ (48,809 ) (59,424 ) (147,678 ) (79,368 ) Realized and unrealized gains (losses) - Life Funds Withheld Assets (38,161 ) (113,916 ) 130,047 (112,023 ) Other 121 1,263 276 1,768 Net realized and unrealized gains (losses) on life retrocession embedded derivative $ (86,849 ) $ (172,077 ) $ (17,355 ) $ (189,623 ) Net adjustments related to future policy benefit reserves, net of tax $ (40,668 ) $ (18,376 ) $ (88,551 ) $ (18,376 ) Net realized and unrealized gains (losses) on derivative instruments - Life Funds Withheld Assets $ 1,377 $ (10,811 ) $ (10,427 ) $ (10,811 ) Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets $ (126,140 ) $ (201,264 ) $ (116,333 ) $ (218,810 )
Summary of contingent credit features	The aggregate fair value of all derivative agreements containing such rating downgrade provisions that were in a liability position and any collateral posted under these agreements as of September 30, 2015 and December 31, 2014 were as follows: Contingent Credit Features - Summary: (U.S. dollars in thousands) September 30, 2015 December 31, 2014 Aggregate fair value of derivative agreements with downgrade provisions in a net liability position $ 15,755 $ 5,770 Collateral posted to counterparty $ — $ —

Goodwill and Other Intangible29

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill [Table Text Block]	The following table presents an analysis of intangible assets broken down between goodwill, intangible assets with an indefinite life and intangible assets with a definite life for the nine months ended September 30, 2015 : (U.S. dollars in thousands) Goodwill Intangible Intangible Total Balance at December 31, 2014 $ 415,936 $ 15,366 $ 16,650 $ 447,952 Additions 791,433 673,000 315,000 1,779,433 Amortization — — (9,922 ) (9,922 ) Foreign Currency Translation (3,775 ) — — (3,775 ) Balance at September 30, 2015 $ 1,203,594 $ 688,366 $ 321,728 $ 2,213,688
Schedule Of Acquired Intangible Assets By Major Class [Table Text Block]	The following table summarizes the intangible assets and their related useful lives recorded in connection with the Catlin Acquisition as of the Acquisition Date: (U.S. dollars in thousands) Amount Estimated Useful Life Lloyd's - Syndicate capacity $ 660,000 Indefinite Insurance licenses 13,000 Indefinite Total identified indefinite life intangible assets $ 673,000 Lloyd's - Managing agent contracts 15,000 15 years Distribution network 290,000 20 years Trademarks / Trade names 10,000 2 years Total identified definite life intangible assets $ 315,000 Total identified intangible assets $ 988,000

Share Capital (Tables)

Share Capital (Tables)	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Summary of shares issued and outstanding	The following table is a summary of ordinary shares issued and outstanding for the nine months ended September 30, 2015 and the year ended December 31, 2014: (in thousands) September 30, 2015 December 31, 2014 Balance – beginning of period 255,183 278,253 Exercise of options 374 424 Net issuance of restricted shares 1,567 1,246 Share buybacks (1) (7,742 ) (24,740 ) Issue of shares 49,935 — Balance – end of period 299,317 255,183 ____________ (1) Includes share buybacks associated with authorized share buyback programs as well as purchases related to satisfying tax withholding obligations of employees in connection with the vesting of restricted shares granted under the Company's equity compensation programs.
Schedule of Valuation Assumptions - Stock Options	The fair value of the options issued was estimated on the date of grant using the Black-Scholes option pricing model using the following weighted average assumptions: Dividend yield 2.00 % Risk free interest rate 1.70 % Volatility 21.6 % Expected lives 6.0 years

Notes Payable and Debt and Fi31

Notes Payable and Debt and Financing Arrangements (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Schedule of financing structure	As of September 30, 2015 , the Company's financing structure, which includes senior and subordinated notes, and bank and loan facilities available from a variety of sources, including commercial banks, is as follows: (U.S. dollars in thousands) September 30, 2015 December 31, 2014 Commitment/ Debt (1) In Use/ Outstanding (2) Commitment/ Debt (1) In Use/ Outstanding (2) Debt: 2.30% Senior Notes due 2018 300,000 297,847 300,000 297,344 5.75% Senior Notes due 2021 400,000 397,415 400,000 397,092 6.375% Senior Notes due 2024 350,000 349,002 350,000 348,920 4.45% Subordinated Notes due 2025 500,000 492,318 — — 6.25% Senior Notes due 2027 325,000 323,179 325,000 323,062 Variable Rate Note, face amount €7m, due 2035 7,823 7,336 — — Variable Rate Note, face amount $27m, due 2036 27,000 25,280 — — Variable Rate Note, face amount $31m, due 2036 31,300 29,305 — — Variable Rate Note, face amount $10m, due 2036 9,800 9,175 — — Variable Rate Note, face amount €11m, due 2036 12,294 11,528 — — 5.25% Senior Notes due 2043 300,000 296,261 300,000 296,162 5.5% Subordinated Notes due 2045 500,000 488,271 — — Total debt carrying value $ 2,763,217 $ 2,726,917 $ 1,675,000 $ 1,662,580 _______________ (1) Excluded from the table are revolving credit facilities of $1.5 billion and $1.6 billion as of September 30, 2015 and December 31, 2014 , respectively. As of September 30, 2015 and December 31, 2014 , $455.9 million and $606.1 million , respectively, were utilized under these facilities to issue letters of credit, leaving $1.0 billion and $ 968.9 million , respectively, available for use under the revolving credit facilities. (2) "In Use/Outstanding" data represent September 30, 2015 and December 31, 2014 accreted values.
Letter of Credit Summary	The Company’s letter of credit facilities and revolving credit facilities as of September 30, 2015 and December 31, 2014 were as follows: Letter of Credit Summary: (U.S. dollars in thousands except percentages) September 30, 2015 (1) December 31, 2014 (1) Revolving credit facilities (2) (3) $ 1,039,100 $ 968,900 Available letter of credit facilities - commitments (4) $ 4,850,000 $ 3,575,000 Available letter of credit facilities - in use $ 2,538,499 $ 1,790,561 Collateralized by certain assets of the Company’s investment portfolio 49.9 % 66.2 % ____________ (1) As of September 30, 2015 and December 31, 2014 , there were eighteen and eight available letter of credit facilities, respectively. (2) As of September 30, 2015 and December 31, 2014 , $976.1 million and $968.9 million , respectively, of revolving credit was available under the Company's syndicated unsecured credit agreement, which currently provides for up to $1 billion of revolving credit loans. The Company has the option to increase the size of the facilities under the syndicated secured and unsecured credit agreements by an additional $500 million across both facilities. Two bilateral facilities assumed as a result of the Catlin Acquisition with commitments totaling $150.0 million also provide for revolving credit loans. As of September 30, 2015 , $63.0 million of revolving credit was available to draw under these facilities. (3) The credit agreements with Citicorp USA, Inc. currently provide for the issuance of letters of credit and revolving credit loans up to an aggregate amount of $345.0 million , compared to $575.0 million available under the credit agreements with Citicorp USA, Inc. as of December 31, 2014 . As of September 30, 2015 , $345.0 million of letters of credit were issued under these agreements, and therefore no amounts are included in this line as available to draw under these facilities. The Company also has the option to increase the maximum amount of the letters of credit and revolving credit loans available under its credit agreements with Citicorp USA, Inc. with the lender's and issuing lender's consent. (4) The available letter of credit facilities include approximately $1 billion that is also included in the "revolving credit facilities" line in this table.

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Summary of related party transactions	During the three and nine months ended September 30, 2015 and 2014 , these contracts resulted in net premiums written, net claims incurred and acquisition costs as summarized below: (U.S. dollars in thousands) Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Net premiums written $ 5,075 $ 31,981 $ 36,596 $ 68,172 Net losses and loss expenses incurred $ 1,402 $ 12,738 $ 10,567 $ 27,038 Acquisition costs $ 1,874 $ 10,969 $ 12,269 $ 26,522

Computation of Earnings Per O33

Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Calculation of earnings per share	The following table sets forth the computation of basic and diluted earnings per ordinary share for the three and nine months ended September 30, 2015 and 2014 : Three Months Ended September 30, Nine Months Ended September 30, (U.S. dollars in thousands, except per share amounts) 2015 2014 2015 2014 Basic earnings per ordinary share & ordinary share equivalents outstanding: Net income (loss) attributable to ordinary shareholders $ 27,282 $ 72,384 $ 978,602 $ 48,841 Weighted average ordinary shares outstanding, in thousands - basic 301,867 264,353 282,506 270,494 Basic earnings per ordinary share & ordinary share equivalents outstanding $ 0.09 $ 0.27 $ 3.46 $ 0.18 Diluted earnings per ordinary share & ordinary share equivalents outstanding: Weighted average ordinary shares outstanding, in thousands - basic 301,867 264,353 282,506 270,494 Impact of share-based compensation and certain conversion features, in thousands 5,087 4,787 4,967 4,418 Weighted average ordinary shares outstanding, in thousands - diluted 306,954 269,140 287,473 274,912 Diluted earnings per ordinary share & ordinary share equivalents outstanding $ 0.09 $ 0.27 $ 3.40 $ 0.18 Dividends per ordinary share $ 0.20 $ 0.16 $ 0.52 $ 0.48

Accumulated Other Comprehensi34

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2015
Comprehensive Income Loss Note [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The changes in AOCI, net of tax, by component for the three and nine months ended September 30, 2015 and 2014 are as follows: Three months ended September 30, 2015 (U.S. dollars in thousands) Unrealized Gains (Losses) on Investments (1) OTTI Losses Recognized in AOCI Foreign Currency Translation Adjustments Underfunded Pension Liability Cash Flow Hedge Total Balance, beginning of period, net of tax $ 1,168,964 $ (64,614 ) $ (9,508 ) $ (21,143 ) $ 2,475 $ 1,076,174 OCI before reclassifications (4,334 ) — (24,267 ) 93 — (28,508 ) Amounts reclassified from AOCI (94,393 ) 2,318 — — 12 (92,063 ) Tax benefit (expense) (2,213 ) (181 ) 1,873 — — (521 ) Net current period OCI - net of tax (100,940 ) 2,137 (22,394 ) 93 12 (121,092 ) Balance, end of period, net of tax $ 1,068,024 $ (62,477 ) $ (31,902 ) $ (21,050 ) $ 2,487 $ 955,082 Three months ended September 30, 2014 (U.S. dollars in thousands) Balance, beginning of period, net of tax $ 1,301,178 $ (84,258 ) $ 1,059 $ (13,278 ) $ 2,333 $ 1,207,034 OCI before reclassifications 51,133 — (14,167 ) 418 — 37,384 Amounts reclassified from AOCI (28,795 ) 6,078 87 — 83 (22,547 ) Tax benefit (expense) 7,906 (115 ) 2,267 — — 10,058 Net current period OCI - net of tax 30,244 5,963 (11,813 ) 418 83 24,895 Balance, end of period, net of tax $ 1,331,422 $ (78,295 ) $ (10,754 ) $ (12,860 ) $ 2,416 $ 1,231,929 Nine months ended September 30, 2015 (U.S. dollars in thousands) Balance, beginning of period, net of tax $ 1,590,114 $ (76,047 ) $ (11,188 ) $ (20,789 ) $ 2,368 $ 1,484,458 OCI before reclassifications (294,341 ) — (28,225 ) (261 ) — (322,827 ) Amounts reclassified from AOCI (256,731 ) 13,916 — — 119 (242,696 ) Tax benefit (expense) 28,982 (346 ) 7,511 — — 36,147 Net current period OCI - net of tax (522,090 ) 13,570 (20,714 ) (261 ) 119 (529,376 ) Balance, end of period, net of tax $ 1,068,024 $ (62,477 ) $ (31,902 ) $ (21,050 ) $ 2,487 $ 955,082 Nine months ended September 30, 2014 (U.S. dollars in thousands) Balance, beginning of period, net of tax $ 822,432 $ (89,190 ) $ 14,541 $ (13,239 ) $ 2,113 $ 736,657 OCI before reclassifications 679,732 — (23,688 ) 379 — 656,423 Amounts reclassified from AOCI (125,770 ) 11,127 87 — 303 (114,253 ) Tax benefit (expense) (44,972 ) (232 ) (1,694 ) — — (46,898 ) Net current period OCI - net of tax 508,990 10,895 (25,295 ) 379 303 495,272 Balance, end of period, net of tax $ 1,331,422 $ (78,295 ) $ (10,754 ) $ (12,860 ) $ 2,416 $ 1,231,929 ____________ (1) Included in these amounts is the impact of Shadow Adjustments as defined in Note 6, "Investments .". As of December 31, 2014 the cumulative impact of the Shadow Adjustments was $445.1 million . During the nine months ended September 30, 2015 , net movements of $(127.4) million were recorded, resulting in a total cumulative net impact of Shadow Adjustments on future policy benefit reserves of $317.7 million as of September 30, 2015 .
Reclassification out of Accumulated Other Comprehensive Income	The reclassifications out of AOCI along with the associated income statement line items affected by component, and the total related tax (expense) benefit for the three and nine months ended September 30, 2015 and 2014 are as follows: Gross Amount Reclassified From AOCI Details About AOCI Components (U.S. dollars in thousands) Three months ended September 30, 2015 Three months ended September 30, 2014 Nine months ended September 30, 2015 Nine months ended September 30, 2014 Affected Line Item in the Statement of Income Unrealized gains and losses on investments: $ (97,761 ) $ (18,665 ) $ (247,339 ) $ (151,049 ) Net realized gains (losses) on investments sold and net unrealized gains (losses) on investments Trading 44,036 8,246 79,158 43,655 OTTI on investments $ (40,668 ) $ (18,376 ) $ (88,550 ) $ (18,376 ) Net realized and unrealized gains (losses) on life retrocession embedded derivative and derivative instruments - Life Funds Withheld Assets $ (94,393 ) $ (28,795 ) $ (256,731 ) $ (125,770 ) Total before tax 1,253 956 5,034 5,108 Provision (benefit) for income tax $ (93,140 ) $ (27,839 ) $ (251,697 ) $ (120,662 ) Net of tax OTTI losses recognized in OCI: $ 1,617 $ 5,686 $ 13,086 $ 9,030 Net realized gains (losses) on investments sold 701 392 830 2,097 OTTI on investments transferred to (from) OCI $ 2,318 $ 6,078 $ 13,916 $ 11,127 Total before tax (10 ) (3 ) (25 ) (120 ) Provision (benefit) for income tax $ 2,308 $ 6,075 $ 13,891 $ 11,007 Net of tax Foreign currency translation: Foreign exchange relating to affiliate investments $ — $ 87 $ — $ 87 Exchange gains (losses) - before tax — — — — Provision (benefit) for income tax $ — $ 87 $ — $ 87 Net of tax Gains and losses on cash flow hedges: Interest rate contracts $ 12 $ 83 $ 119 $ 303 Interest Expense — — — — Provision (benefit) for income tax $ 12 $ 83 $ 119 $ 303 Net of tax Total reclassifications for the period, gross of tax $ (92,063 ) $ (22,547 ) $ (242,696 ) $ (114,253 ) Tax benefit (expense) 1,243 953 5,009 4,988 Total reclassifications for the period, net of tax $ (90,820 ) $ (21,594 ) $ (237,687 ) $ (109,265 )

Significant Accounting Polici35

Significant Accounting Policies (Details) $ in Millions	3 Months Ended
	Sep. 30, 2014USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Adjustment to premiums earned and associated tax accruals, amount	$ 20

Acquisition and Disposals - Acq

Acquisition and Disposals - Acquisition consideration (Details) £ / shares in Units, $ / shares in Units, £ in Thousands, $ in Thousands	May. 01, 2015USD ($)shares$ / shares		May. 01, 2015GBP (£)shares£ / shares
Business Acquisition [Line Items]
Closing price per XL share on April 30, 2015 | $ / shares	$ 37.08	[1]
Catlin Group Limited
Business Acquisition [Line Items]
Shares outstanding (including dilutive effects of warrants) that will receive cash and share consideration	384,118,000
Exchange ratio per the merger agreement	0.13		0.13
Share issuance to Catlin shareholders	49,935,000		49,935,000
Share issuance consideration | $	$ 1,851,601
Cash price component, per share in GBP | £ / shares			£ 3.88
Foreign exchange rate: GBP/USD	1.5349
Cash consideration	$ 2,287,579		£ 1,490,377
Total acquisition consideration | $	$ 4,139,180
[1]	The closing market price of XL Shares on the Acquisition Date represents the fair value of XL shares issued as part of the Acquisition Consideration.

Acquisition and Disposals - A37

Acquisition and Disposals - Acquisition narrative (Details) £ / shares in Units, $ / shares in Units, £ in Thousands, $ in Thousands	Sep. 28, 2015USD ($)	May. 01, 2015USD ($)shares$ / shares	May. 01, 2015GBP (£)shares£ / shares	Sep. 30, 2015USD ($)$ / shares	Sep. 30, 2015USD ($)$ / shares	Mar. 30, 2015USD ($)	Jan. 08, 2015GBP (£)	Dec. 31, 2014USD ($)$ / shares
Business Acquisition [Line Items]
Ordinary shares, par value (in dollars per share) | $ / shares				$ 0.01	$ 0.01			$ 0.01
Goodwill				$ 1,203,594	$ 1,203,594			$ 415,936
Face amount of issued debt				2,763,217	2,763,217			$ 1,675,000
Goodwill acquired during the period					791,433
Indefinite-lived intangible assets acquired during the period					673,000
Finite-lived intangible assets acquired during the period					315,000
Intangibles Assets Arising from Insurance Contracts Acquired in Business Combination, Amortization Expense				140,400	$ 323,700
Catlin Group Limited
Business Acquisition [Line Items]
Ordinary shares, par value (in dollars per share) | $ / shares		$ 0.01
Cash price component, per share in GBP | £ / shares			£ 3.88
Exchange ratio per the merger agreement | shares		0.13	0.13
Share issuance to Catlin shareholders | shares		49,935,000	49,935,000
Cash consideration		$ 2,287,579	£ 1,490,377
Face amount of issued debt						$ 1,000,000
Goodwill acquired during the period		778,043
Indefinite-lived intangible assets acquired during the period		673,000
Finite-lived intangible assets acquired during the period		315,000
VOBA, amortization period					2 years
Adjustment to reserves, amortization period					20 years
Deferred tax liability		94,071
Acquisition related costs					$ 63,000
Business Combination Measurement Period					12 months
Catlin Group Limited | Operating expense
Business Acquisition [Line Items]
Acquisition related costs					$ 48,500
Catlin Group Limited | Interest expense
Business Acquisition [Line Items]
Acquisition related costs					14,500
Catlin Group Limited | Net deferred tax liability excluding valuation allowance
Business Acquisition [Line Items]
Deferred tax liability		22,100
Catlin Group Limited | Valuation allowance
Business Acquisition [Line Items]
Deferred tax liability		72,000
Catlin Group Limited | Intangible assets
Business Acquisition [Line Items]
Deferred tax liability		133,800
Catlin Group Limited | Loss carryforwards
Business Acquisition [Line Items]
Deferred tax liability		17,400
Catlin Group Limited | Unpaid losses and loss adjustment expenses, deferred acquisition costs and VOBA
Business Acquisition [Line Items]
Deferred tax liability		8,800
Catlin Group Limited | Other temporary differences
Business Acquisition [Line Items]
Deferred tax liability		500
Catlin Group Limited | Fixed assets
Business Acquisition [Line Items]
Deferred tax liability		13,000
Catlin Group Limited | Cash on hand
Business Acquisition [Line Items]
Cash consideration		1,310,000
Catlin Group Limited | Proceeds from debt issuance
Business Acquisition [Line Items]
Cash consideration		$ 980,600
Catlin Group Limited | XL Cayman
Business Acquisition [Line Items]
Available letter of credit facilities - commitments | £							£ 1,600,000
Catlin Inc
Business Acquisition [Line Items]
Release of valuation allowance, deferred tax asset	$ 47,500			$ 29,700	$ 17,800
Catlin Inc | XL Ireland
Business Acquisition [Line Items]
Percentage of voting interests acquired	100.00%

Acquisition and Disposals - Fai

Acquisition and Disposals - Fair value of assets and liabilities acquired (Details) - USD ($) $ in Thousands		May. 01, 2015	Sep. 30, 2015
LIABILITIES
Goodwill			$ 791,433
Catlin Group Limited
ASSETS
Fixed maturities, at fair value		$ 6,266,489
Short-term investments, at fair value		634,599
Equity investments, at fair value		236,230
Investment in affiliates		216,843
Other investments		386,828
Total investments		7,740,989
Cash and cash equivalents	[1]	1,267,565
Unpaid losses and loss expenses recoverable		1,493,267
Reinsurance balances receivable		299,579
Ceded unearned premiums		1,143,852
Deferred acquisition costs and value of business acquired		679,259
Intangible assets		988,000
Other assets		314,168
Total assets		16,516,563
LIABILITIES
Unpaid losses and loss expenses		6,933,144
Unearned premiums		3,742,234
Reinsurance balances payable		1,441,749
Notes payable and debt		82,066
Payable for investments purchased		34,149
Deferred tax liability		94,071
Other liabilities		265,728
Total liabilities		12,593,141
Net assets acquired before non-controlling interest		3,923,422
Non-controlling interest in equity of consolidated subsidiaries		562,285
Net assets acquired		3,361,137
Acquisition consideration		4,139,180
Goodwill		778,043
Catlin Group Limited | Accrued investment income
ASSETS
Receivables acquired		35,063
Catlin Group Limited | Premiums receivable
ASSETS
Receivables acquired		2,545,188
Catlin Group Limited | Receivable from investments sold
ASSETS
Receivables acquired		$ 9,633
[1]	Includes Restricted Cash

Acquisition and Disposals - Tra

Acquisition and Disposals - Transaction related costs (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Severance related costs
Business Combination, Separately Recognized Transactions [Line Items]
Costs incurred in 2015	$ 27,778
2015 payments	14,078
Liabilities at September 30, 2015	13,700
Retention and other compensation costs
Business Combination, Separately Recognized Transactions [Line Items]
Costs incurred in 2015	16,363
2015 payments	7,343
Liabilities at September 30, 2015	9,020
Facilities-related costs
Business Combination, Separately Recognized Transactions [Line Items]
Costs incurred in 2015	6,689
2015 payments	6,689
Liabilities at September 30, 2015	0
Consulting and other
Business Combination, Separately Recognized Transactions [Line Items]
Costs incurred in 2015	32,215
2015 payments	23,723
Liabilities at September 30, 2015	$ 8,492

Acquisition and Disposals - Fin

Acquisition and Disposals - Financial results (Details) - Catlin Group Limited $ in Thousands	5 Months Ended
	Sep. 30, 2015USD ($)
Business Combination Results of Operations [Line Items]
Total revenues	$ 1,770,886
Net income (loss)	$ 65,796

Acquisition and Disposals - Sup

Acquisition and Disposals - Supplemental pro forma financial information (Details) - Catlin Group Limited - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Business Combination Pro Forma Information [Line Items]
Total revenues	$ 7,997,602	$ 8,391,849
Net income attributable to ordinary shareholders	$ 986,918	$ 226,983
Earnings (loss) per ordinary share and ordinary share equivalent – basic (in dollars per share)	$ 3.24	$ 0.71
Earnings (loss) per ordinary share and ordinary share equivalent – diluted (in dollars per share)	$ 3.19	$ 0.70

Acquisition and Disposals - Sal

Acquisition and Disposals - Sale of strategic operating affiliate (Details) - ARX Holding Corporation - USD ($) $ in Millions	Apr. 02, 2015	Apr. 01, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity method investment, ownership percentage		40.60%
Investment in affiliates		$ 220.2
Consideration received		$ 560.6
Gain on disposal	$ 340.4

Acquisition and Disposals - Imp

Acquisition and Disposals - Impact of Life Retro arrangements (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Underwriting profit (loss)		$ 104,648	$ 139,138	$ 447,186		$ 371,444
Net investment income		225,146	226,430	656,863		692,392
Exchange (gains) losses		(11,661)	23,348	(49,425)		(8,234)
Other income and expenses	[1]	(4,420)	(3,058)	(12,292)		(6,410)
Net realized and unrealized gains (losses) on life retrocession embedded derivative		(7,903)	5,131	57,127		18,540
Net income (loss)		85,171	109,967	1,078,760		125,865
Change in adjustments related to future policy benefit reserves, net of tax		40,681	51,286	127,365		(423,179)
Change in cumulative translation adjustment		(22,394)	(11,813)	(20,714)		(25,295)
Comprehensive income (loss)		(121,092)	24,895	(529,376)		495,272
XL Re Life (SAC) Ltd
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Comprehensive income (loss)		0
Life Funds Withheld Assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net investment income		46,586	56,474	143,869		75,639
Net realized gains (losses) on investments sold		53,780	2,022	174,555		2,646
Net unrealized gains (losses) on investments, trading securities		(149)	0	(18,932)		0
OTTI on investments		(2,023)	(7,494)	(10,110)		(16,265)
Net realized and unrealized gains (losses) on life retrocession embedded derivative		(126,140)	(201,264)	(116,333)		(218,810)
Change in net unrealized gains (losses) on investments, net of tax		(33,569)	93,921	(317,500)		106,218
Life Funds Withheld Assets | XL Re Life (SAC) Ltd
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Underwriting profit (loss)		0	3,711	603	[2]	3,711
Net investment income		46,586	56,474	143,869		75,639
Net realized gains (losses) on investments sold		53,780	2,022	174,555		2,646
Net unrealized gains (losses) on investments, trading securities		(149)	0	(18,932)		0
OTTI on investments		(2,023)	(7,494)	(10,110)		(16,265)
Exchange (gains) losses		8,754	2,062	(5,932)		2,062
Other income and expenses		(121)	124	2,354		105
Net realized and unrealized gains (losses) on life retrocession embedded derivative		(126,140)	(201,264)	(116,333)		(218,810)
Net income (loss)		(19,313)	(144,365)	170,074		(150,912)
Change in net unrealized gains (losses) on investments, net of tax		(33,569)	93,921	(317,500)		106,218
Change in adjustments related to future policy benefit reserves, net of tax		40,681	51,286	127,365		51,286
Change in cumulative translation adjustment		12,201	2,869	20,664		(2,881)
Total changes to other comprehensive income as a result of Life Retro Arrangements		19,313	148,076	(169,471)		154,623
Comprehensive income (loss)		$ 0	$ 3,711	$ 603		$ 3,711
[1]	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
[2]	The underwriting profit of $0.6 million relates to a premium adjustment during the nine months ended September 30, 2015 relating to the Life Retro Arrangements transaction. Excluding this transaction, the impact to comprehensive income relating to the Life Retro Arrangements was nil for the nine months ended September 30, 2015.

Acquisition and Disposals - S44

Acquisition and Disposals - Sale of Life Reinsurance narrative (Details) - USD ($) $ in Thousands	May. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Future policy benefit reserves		$ 4,323,748		$ 4,323,748			$ 4,707,199
Future policy benefit reserves recoverable		3,886,297		3,886,297			4,265,678
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)		930,834		930,834			$ 1,155,016
Underwriting profit (loss)		104,648	$ 139,138	447,186		$ 371,444
Comprehensive income (loss)		(121,092)	24,895	(529,376)		495,272
XL Re Life (SAC) Ltd
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale of subsidiary stock, percentage	100.00%
Consideration received	$ 570,000
Quota share reinsurance percentage	100.00%
Future policy benefit reserves recoverable		3,900,000		3,900,000
Loss on disposal						621,300
Funds withheld asset		4,800,000		4,800,000
Comprehensive income (loss)		0
Life insurance product line | XL Re Life (SAC) Ltd
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Future policy benefit reserves	$ 5,200,000
Future policy benefit reserves retained	400,000	400,000		400,000
Future policy benefit reserves recoverable	$ 4,800,000
Life Funds Withheld Assets | XL Re Life (SAC) Ltd
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Underwriting profit (loss)		0	3,711	603	[1]	3,711
Comprehensive income (loss)		$ 0	$ 3,711	$ 603		$ 3,711
[1]	The underwriting profit of $0.6 million relates to a premium adjustment during the nine months ended September 30, 2015 relating to the Life Retro Arrangements transaction. Excluding this transaction, the impact to comprehensive income relating to the Life Retro Arrangements was nil for the nine months ended September 30, 2015.

Acquisition and Disposals - New

Acquisition and Disposals - New Energy Risk narrative (Details) - USD ($) $ in Thousands	Jul. 24, 2015	Sep. 30, 2015
Business Acquisition [Line Items]
Goodwill acquired during the period		$ 791,433
New Energy Risk Inc.
Business Acquisition [Line Items]
Percentage of voting interests acquired	63.63%
Original ownership percentage	31.16%
Ownership percentage following additional purchase of shares	94.79%
Ownership percentage held by noncontrolling interest	5.21%
Cash consideration	$ 8,800
Gain on fair value adjustment	2,500
Goodwill acquired during the period	$ 13,400

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of assets and liabilities that were accounted for at fair value (Details) - USD ($) $ in Thousands		Sep. 30, 2015		Dec. 31, 2014
Assets
Fixed maturities, at fair value		$ 33,276,322		$ 29,359,034
Equity securities, at fair value		969,706		868,292
Short-term investments, at fair value		546,020		256,727
Total investments available for sale		34,792,048		30,484,053
Fixed maturities, trading at fair value		914,337		1,171
Collateral and counterparty netting, assets	[1]	(3,900)		(696)
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)		930,834		1,155,016
Collateral and counterparty nettings, liabilities	[1]	(3,900)		(696)
Recurring
Assets
Total investments available for sale		34,792,048		30,484,053
Cash equivalents	[2]	1,396,002		1,501,832
Other investments	[3]	1,329,780		894,057
Other assets	[1]	70,215		135,963
Total assets accounted for at fair value		38,661,548		33,150,274
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)	[4]	468,187		450,831
Financial instruments sold, but not yet purchased	[5]	2,281		30,406
Other liabilities	[1]	45,810		30,488
Total liabilities accounted for at fair value		516,278		511,725
Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets
Total investments available for sale		478,815		502,284
Cash equivalents	[2]	940,303		1,103,877
Other investments		0		0
Other assets		0		0	[1]
Total assets accounted for at fair value		1,420,558		1,606,621
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)	[4]	0		0
Financial instruments sold, but not yet purchased	[5]	1,588		4,737
Other liabilities	[1]	0		0
Total liabilities accounted for at fair value		1,588		4,737
Recurring | Significant other observable inputs (Level 2)
Assets
Total investments available for sale		33,851,296		29,280,719
Cash equivalents	[2]	455,699		397,955
Other investments	[3]	1,051,558		708,974
Other assets	[1]	59,231		122,996
Total assets accounted for at fair value		36,489,847		30,644,553
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)	[4]	468,187		450,831
Financial instruments sold, but not yet purchased	[5]	693		25,669
Other liabilities	[1]	25,142		7,757
Total liabilities accounted for at fair value		494,022		484,257
Recurring | Significant other unobservable inputs (Level 3)
Assets
Total investments available for sale		461,937		701,050
Cash equivalents	[2]	0		0
Other investments	[3]	278,222		185,083
Other assets	[1]	14,884		13,663
Total assets accounted for at fair value		755,043		899,796
Liabilities
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable)	[4]	0		0
Financial instruments sold, but not yet purchased		0	[5]	0
Other liabilities	[1]	24,568		23,427
Total liabilities accounted for at fair value		24,568		23,427
Excluding Life Funds Withheld Assets
Assets
Fixed maturities, at fair value		29,637,961		24,177,469
Equity securities, at fair value		969,706		868,292
Short-term investments, at fair value		546,020		256,727
Total investments available for sale		31,153,687		25,302,488
Excluding Life Funds Withheld Assets | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		4,298,723		2,171,953
Excluding Life Funds Withheld Assets | RMBS - Agency
Assets
Fixed maturities, at fair value		3,923,489		3,728,576
Excluding Life Funds Withheld Assets | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		362,965		427,351
Excluding Life Funds Withheld Assets | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		850,084		1,052,544
Excluding Life Funds Withheld Assets | Collateralized debt obligations
Assets
Fixed maturities, at fair value		410,163		692,034
Excluding Life Funds Withheld Assets | Other asset-backed securities
Assets
Fixed maturities, at fair value		2,095,598	[6]	1,065,293	[7]
Excluding Life Funds Withheld Assets | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		2,648,670		2,021,272
Excluding Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		5,120,149		4,240,073
Excluding Life Funds Withheld Assets | Recurring
Assets
Fixed maturities, at fair value		29,637,961		24,177,469
Equity securities, at fair value		969,706		868,292
Short-term investments, at fair value	[8],[9]	546,020		256,727
Total investments available for sale		31,153,687		25,302,488
Excluding Life Funds Withheld Assets | Recurring | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		4,298,723		2,171,953
Excluding Life Funds Withheld Assets | Recurring | RMBS - Agency
Assets
Fixed maturities, at fair value		3,923,489		3,728,576
Excluding Life Funds Withheld Assets | Recurring | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		362,965		427,351
Excluding Life Funds Withheld Assets | Recurring | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		850,084		1,052,544
Excluding Life Funds Withheld Assets | Recurring | Collateralized debt obligations
Assets
Fixed maturities, at fair value		410,163		692,034
Excluding Life Funds Withheld Assets | Recurring | Other asset-backed securities
Assets
Fixed maturities, at fair value	[8]	2,095,598		1,065,293
Excluding Life Funds Withheld Assets | Recurring | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		2,648,670		2,021,272
Excluding Life Funds Withheld Assets | Recurring | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		5,120,149		4,240,073
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets
Fixed maturities, at fair value		0		0
Equity securities, at fair value		478,815		502,284
Short-term investments, at fair value	[8],[9]	0		0
Total investments available for sale		478,815		502,284
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Agency
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Collateralized debt obligations
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Other asset-backed securities
Assets
Fixed maturities, at fair value	[8]	0		0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2)
Assets
Fixed maturities, at fair value		29,176,024		23,476,419
Equity securities, at fair value		490,891		366,008
Short-term investments, at fair value	[8],[9]	546,020		256,727
Total investments available for sale		30,212,935		24,099,154
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		4,298,723		2,171,953
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Agency
Assets
Fixed maturities, at fair value		3,920,607		3,726,666
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		362,965		427,351
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		850,084		1,052,544
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Collateralized debt obligations
Assets
Fixed maturities, at fair value		2,500		4,076
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Other asset-backed securities
Assets
Fixed maturities, at fair value	[8]	2,059,478		1,060,005
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		2,648,670		2,021,272
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		5,120,149		4,240,073
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3)
Assets
Fixed maturities, at fair value		461,937		701,050
Equity securities, at fair value		0		0
Short-term investments, at fair value	[8],[9]	0		0
Total investments available for sale		461,937		701,050
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Agency
Assets
Fixed maturities, at fair value		2,882		1,910
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Collateralized debt obligations
Assets
Fixed maturities, at fair value		407,663		687,958
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Other asset-backed securities
Assets
Fixed maturities, at fair value	[8]	36,120		5,288
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | US States and political subdivisions of the States
Assets
Fixed maturities, at fair value		0		0
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		0		0
Life Funds Withheld Assets
Assets
Fixed maturities, at fair value		3,638,361		5,181,565
Fixed maturities, trading at fair value		985,223		1,171
Life Funds Withheld Assets | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		13,412		18,724
Fixed maturities, trading at fair value		4,610
Life Funds Withheld Assets | RMBS - Agency
Assets
Fixed maturities, at fair value		814		3,782
Life Funds Withheld Assets | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		28,833		85,335
Life Funds Withheld Assets | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		141,166		193,167
Fixed maturities, trading at fair value		4,982
Life Funds Withheld Assets | Other asset-backed securities
Assets
Fixed maturities, at fair value		162,871		273,541
Fixed maturities, trading at fair value		19,872
Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		1,141,365		1,789,036
Fixed maturities, trading at fair value		342,746
Life Funds Withheld Assets | Recurring
Assets
Fixed maturities, at fair value		3,638,361		5,181,565
Fixed maturities, trading at fair value		985,223		1,171
Cash equivalents	[2]	88,280		133,198
Life Funds Withheld Assets | Recurring | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		13,412		18,724
Fixed maturities, trading at fair value		4,610
Life Funds Withheld Assets | Recurring | RMBS - Agency
Assets
Fixed maturities, at fair value		814		3,782
Life Funds Withheld Assets | Recurring | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		28,833		85,335
Life Funds Withheld Assets | Recurring | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		141,166		193,167
Fixed maturities, trading at fair value		4,982
Life Funds Withheld Assets | Recurring | Other asset-backed securities
Assets
Fixed maturities, at fair value		162,871		273,541
Fixed maturities, trading at fair value		19,872
Life Funds Withheld Assets | Recurring | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		1,141,365		1,789,036
Fixed maturities, trading at fair value		342,746
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0		0
Cash equivalents	[2]	1,440		460
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Agency
Assets
Fixed maturities, at fair value		0		0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		0		0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Other asset-backed securities
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2)
Assets
Fixed maturities, at fair value		3,638,361		5,181,565
Fixed maturities, trading at fair value		985,223		1,171
Cash equivalents	[2]	86,840		132,738
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		13,412		18,724
Fixed maturities, trading at fair value		4,610
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Agency
Assets
Fixed maturities, at fair value		814		3,782
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		28,833		85,335
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		141,166		193,167
Fixed maturities, trading at fair value		4,982
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Other asset-backed securities
Assets
Fixed maturities, at fair value		162,871		273,541
Fixed maturities, trading at fair value		19,872
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		1,141,365		1,789,036
Fixed maturities, trading at fair value		342,746
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3)
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0		0
Cash equivalents	[2]	0		0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | U.S. Government and Government - Related/Supported
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Agency
Assets
Fixed maturities, at fair value		0		0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Non-Agency
Assets
Fixed maturities, at fair value		0		0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Commercial mortgage-backed securities
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Other asset-backed securities
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Financial Services Sector | Excluding Life Funds Withheld Assets | Corporate
Assets
Fixed maturities, at fair value		3,072,530		2,761,916
Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Corporate
Assets
Fixed maturities, at fair value		3,072,530		2,761,916
Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate
Assets
Fixed maturities, at fair value		0		0
Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate
Assets
Fixed maturities, at fair value		3,062,530		2,761,916
Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate
Assets
Fixed maturities, at fair value		10,000		0
Financial Services Sector | Life Funds Withheld Assets | Corporate
Assets
Fixed maturities, at fair value		669,788		801,019
Fixed maturities, trading at fair value		219,767
Financial Services Sector | Life Funds Withheld Assets | Recurring | Corporate
Assets
Fixed maturities, at fair value		669,788		801,019
Fixed maturities, trading at fair value		219,767
Financial Services Sector | Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Financial Services Sector | Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate
Assets
Fixed maturities, at fair value		669,788		801,019
Fixed maturities, trading at fair value		219,767
Financial Services Sector | Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Corporate
Assets
Fixed maturities, at fair value		6,855,590	[6]	6,016,457	[7]
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Corporate
Assets
Fixed maturities, at fair value	[8]	6,855,590		6,016,457
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate
Assets
Fixed maturities, at fair value	[8]	0		0
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate
Assets
Fixed maturities, at fair value	[8]	6,850,318		6,010,563
Non-Financial Services Sector | Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate
Assets
Fixed maturities, at fair value	[8]	5,272		5,894
Non-Financial Services Sector | Life Funds Withheld Assets | Corporate
Assets
Fixed maturities, at fair value		1,480,112		2,016,961
Fixed maturities, trading at fair value		393,246		1,171
Non-Financial Services Sector | Life Funds Withheld Assets | Recurring | Corporate
Assets
Fixed maturities, at fair value		1,480,112		2,016,961
Fixed maturities, trading at fair value		393,246		1,171
Non-Financial Services Sector | Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		0		0
Non-Financial Services Sector | Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate
Assets
Fixed maturities, at fair value		1,480,112		2,016,961
Fixed maturities, trading at fair value		393,246		1,171
Non-Financial Services Sector | Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate
Assets
Fixed maturities, at fair value		0		0
Fixed maturities, trading at fair value		$ 0		$ 0
[1]	Other assets and other liabilities include derivative instruments. The derivative balances included in each category are reported on a gross basis by level with a netting adjustment presented separately in the Collateral and Counterparty Netting column. The fair values of the individual derivative contracts are reported gross in their respective levels based on the fair value hierarchy. For further details regarding derivative fair values and associated collateral received or paid, see Note 7, "Derivative Instruments," to the Unaudited Consolidated Financial Statements.
[2]	Cash equivalents balances subject to fair value measurement include certificates of deposit and money market funds. Operating cash balances are not subject to recurring fair value measurement guidance.
[3]	The Other investments balance excludes certain structured transactions including certain investments in project finance transactions, and a payment obligation and liquidity financing provided to a structured credit vehicle as a part of a third party medium term note facility. These investments, which totaled $346.4 million as of September 30, 2015 and $354.4 million as of December 31, 2014, are carried at amortized cost. For further information, see Item 8, Note 8, "Other Investments," to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2014.
[4]	Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable) include balances related to the life retrocession embedded derivative, under which all investment results associated with the Life Funds Withheld Assets related to the Life Retro Arrangements described in Note 3(e), "Acquisitions and Disposals - Sale of Life Reinsurance Subsidiary," accrue to the benefit of GCLR.
[5]	Financial instruments sold, but not yet purchased, represent "short sales" and are included within "Payable for investments purchased" on the balance sheets.
[6]	Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $74.3 million and an amortized cost of $64.6 million. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes.
[7]	Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $79.9 million and an amortized cost of $68.4 million. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes.
[8]	Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes had a fair value of $74.3 million and $79.9 million and an amortized cost of $64.6 million and $68.4 million as of September 30, 2015 and December 31, 2014, respectively. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate values of these notes.
[9]	Short-term investments consist primarily of Corporate securities and U.S. and Non-U.S. Government and Government-Related/Supported securities.

Fair Value Measurements - Addit

Fair Value Measurements - Additional information about assets and liabilities measured at fair value on a recurring basis (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative contracts - net
Level 3 liabilities
Balance, beginning of period		$ (9,753)	$ (18,910)	$ (9,764)	$ (29,110)
Realized gains (losses)		0	0	0	0
Movement in unrealized gains (losses)		69	710	80	10,910
Purchases and issuances	[1]	0	0	0	0
Sales			0	0	0
Settlements		0	0	0	0
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	0
Balance, end of period		(9,684)	(18,200)	(9,684)	(18,200)
Movement in total gains (losses) above relating to instruments still held at the reporting date		69	710	80	10,910
RMBS - Agency
Level 3 assets
Balance, beginning of period		3,038	6,896	1,910	10,473
Realized gains (losses)		0	(1)	0	5
Movement in unrealized gains (losses)		(2)	(7)	(4)	(20)
Purchases and issuances	[1]	0	120	1,297	120
Sales		0	0	0	0
Settlements		(154)	(526)	(321)	(3,124)
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	(972)
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		2,882	6,482	2,882	6,482
Movement in total gains (losses) above relating to instruments still held at the reporting date		(2)	(8)	(2)	(14)
RMBS - Non-Agency
Level 3 assets
Balance, beginning of period		0	11	0	9
Realized gains (losses)		0	0	0	0
Movement in unrealized gains (losses)		0	(1)	0	1
Purchases and issuances	[1]	0	0	0	0
Sales		0	0	0	0
Settlements		0	0	0	0
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	0
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		0	10	0	10
Movement in total gains (losses) above relating to instruments still held at the reporting date		0	0	0	2
Commercial mortgage-backed securities
Level 3 assets
Balance, beginning of period		0	1,945	0	12,533
Realized gains (losses)		0	0	0	3
Movement in unrealized gains (losses)		0	0	0	(3)
Purchases and issuances	[1]	0	0	0	1,376
Sales		0	0	0	0
Settlements		0	(569)	0	(12,533)
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	(1,376)	0	(1,376)
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		0	0	0	0
Movement in total gains (losses) above relating to instruments still held at the reporting date		0	0	0	0
Collateralized debt obligations
Level 3 assets
Balance, beginning of period		484,171	732,824	687,958	710,253
Realized gains (losses)		(8,469)	707	(8,209)	3,163
Movement in unrealized gains (losses)		8,994	1,591	16,994	13,604
Purchases and issuances	[1]	2,101	82,695	14,042	185,710
Sales		(56,576)	(7,489)	(211,661)	(48,313)
Settlements		(22,558)	(67,845)	(91,461)	(121,934)
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	0
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		407,663	742,483	407,663	742,483
Movement in total gains (losses) above relating to instruments still held at the reporting date		164	2,297	4,889	15,513
Other asset-backed securities
Level 3 assets
Balance, beginning of period		42,745	11,704	5,288	11,877
Realized gains (losses)		553	3	644	(17)
Movement in unrealized gains (losses)		(976)	(113)	(966)	93
Purchases and issuances	[1]	3,334	2,182	43,962	5,182
Sales		0	0	0	0
Settlements		(3,087)	(1,726)	(6,359)	(5,085)
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		(6,449)	0	(6,449)	0
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		36,120	12,050	36,120	12,050
Movement in total gains (losses) above relating to instruments still held at the reporting date		(5)	(110)	95	76
Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Level 3 assets
Balance, beginning of period		0	0	0	0
Realized gains (losses)		0	0	0	0
Movement in unrealized gains (losses)		0	0	0	0
Purchases and issuances	[1]	0	0	0	0
Sales		0	0	0	0
Settlements		0	0	0	0
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	0
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		0	0	0	0
Movement in total gains (losses) above relating to instruments still held at the reporting date		0	0	0	0
Short-term investments
Level 3 assets
Balance, beginning of period		0	0	0	2,015
Realized gains (losses)		0	0	0	0
Movement in unrealized gains (losses)		0	0	0	(15)
Purchases and issuances	[1]	0	0	0	0
Sales		0	0	0	0
Settlements		0	0	0	(2,000)
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	0
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		0	0	0	0
Movement in total gains (losses) above relating to instruments still held at the reporting date		0	0	0	0
Other investments
Level 3 assets
Balance, beginning of period		255,672	124,475	185,083	113,472
Realized gains (losses)		9,185	1,850	11,778	10,541
Movement in unrealized gains (losses)		(5,567)	2,790	(7,533)	2,508
Purchases and issuances	[1]	30,519	22,308	103,822	43,394
Sales		(1,417)	0	(1,417)	0
Settlements		(10,170)	(4,888)	(13,511)	(23,380)
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	0
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		278,222	146,535	278,222	146,535
Movement in total gains (losses) above relating to instruments still held at the reporting date		3,618	4,639	4,246	13,048
Financial Services Sector | Corporate
Level 3 assets
Balance, beginning of period		10,000	0	0	0
Realized gains (losses)		0	0	0	0
Movement in unrealized gains (losses)		0	0	0	0
Purchases and issuances	[1]	0	0	10,000	0
Sales		0	0	0	0
Settlements		$ 0	0	0	0
Transfers into Level 3			0	0	0
Transfers out of Level 3		$ 0	0	0	0
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		10,000	0	10,000	0
Movement in total gains (losses) above relating to instruments still held at the reporting date		0	0	0	0
Non-Financial Services Sector | Corporate
Level 3 assets
Balance, beginning of period		5,554	3,933	5,894	31,573
Realized gains (losses)		(45)	3	(186)	158
Movement in unrealized gains (losses)		(1)	24	3	(72)
Purchases and issuances	[1]	0	2,316	(123)	3,759
Sales		0	0	0	0
Settlements		(236)	0	(316)	(5,513)
Transfers into Level 3		0	766	0	766
Transfers out of Level 3		0	0	0	(23,629)
Fixed maturities to short-term investments classification change		0	0	0	0
Balance, end of period		5,272	7,042	5,272	7,042
Movement in total gains (losses) above relating to instruments still held at the reporting date		$ (1)	$ 27	$ (137)	$ 117
[1]	Includes assets acquired as result of the transaction described in Note 3(c), "Acquisitions and Disposals - Catlin Acquisition."

Fair Value Measurements - Finan

Fair Value Measurements - Financial instruments not carried at fair value (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposit liabilities	$ 1,194,815	$ 1,245,367
Notes payable and debt	2,726,917	1,662,580
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	346,359	354,382
Deposit liabilities	1,194,815	1,245,367
Notes payable and debt	2,726,917	1,662,580
Financial Liabilities	3,921,732	2,907,947
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial Assets	363,251	371,625
Deposit liabilities	1,471,562	1,543,761
Notes payable and debt	2,919,907	1,897,854
Financial Liabilities	$ 4,391,469	$ 3,441,615

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	$ 33,276,322	$ 29,359,034
Amortized cost of fixed maturities	32,207,019	27,728,771
Other investments - structured transactions	$ 346,400	$ 354,400
Spread on U.S. treasury for discounting deposit liabilities	0.505%	0.295%
Medium term notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	$ 74,300	$ 79,900
Amortized cost of fixed maturities	$ 64,600	$ 68,400

Segment Information - Statement

Segment Information - Statement of earnings by segment (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Segment Reporting Information [Line Items]
Gross premiums written		$ 2,739,350		$ 1,684,198		$ 8,375,845		$ 6,395,373
Net premiums written		2,091,028		1,233,985		6,060,608		4,721,680
Net premiums earned		2,423,552		1,473,412		5,839,605		4,458,845
Net losses and loss expenses		1,486,864	[1]	879,689		3,449,354	[1]	2,737,960
Acquisition costs		409,173	[1]	182,882		904,486	[1]	566,915
Operating expenses	[2]	422,867		271,703		1,038,579		782,526
Underwriting profit (loss)		104,648		139,138		447,186		371,444
Net results from structured products		4,437	[3]	5,291	[4]	14,719	[5]	48,129	[6]
Net fee income and other	[7]	(4,420)		(3,058)		(12,292)		(6,410)
Loss on sale of life reinsurance subsidiary		0		0		0		666,423
Net realized gains (losses) on investments		51,407		4,341		154,265		96,267
Net realized and unrealized gains (losses) on derivative instruments		(7,903)		5,131		57,127		18,540
Net income (loss) from investment fund affiliates and operating affiliates	[8]	4,481		44,521		103,317		169,530
Gain on sale of operating affiliate		0		0		340,407		0
Exchange (gains) losses		11,661		(23,348)		49,425		8,234
Corporate operating expenses		135,500		55,322		328,930		163,155
Contribution from P&C and Corporate and Other		88,927		171,727		1,220,212		280,736
Interest expense	[9]	40,798		31,703		121,317		96,147
Non-controlling interests		57,889		37,583		100,158		77,024
Income tax		(37,042)		30,057		20,135		58,724
Net income (loss) attributable to ordinary shareholders		27,282		72,384		978,602		48,841
Corporate and Other
Segment Reporting Information [Line Items]
Gross premiums written	[10]	80,208		83,496		234,602		254,503
Net premiums written	[10]	17,812		19,739		50,576		154,568
Net premiums earned	[10]	17,812		19,739		50,576		154,568
Net losses and loss expenses	[10]	22,579	[1]	20,101		64,047	[1]	218,987
Acquisition costs	[10]	4,729	[1]	2,090		8,230	[1]	13,151
Operating expenses	[2],[10]	(26)		2,785		846		8,182
Underwriting profit (loss)	[10]	(9,470)		(5,237)		(22,547)		(85,752)
Net results from structured products	[10]	0	[3]	0	[4]	0	[5]	0	[6]
Net fee income and other	[7],[10]	254		167		432		257
Loss on sale of life reinsurance subsidiary	[10]							666,423
Net realized and unrealized gains (losses) on derivative instruments	[10]	(7,903)		5,131		57,127		18,540
Net income (loss) from investment fund affiliates and operating affiliates	[8],[10]	4,481		44,521		103,317		169,530
Gain on sale of operating affiliate	[10]					340,407
Exchange (gains) losses	[10]	11,661		(23,348)		49,425		8,234
Corporate operating expenses	[10]	135,500		55,322		328,930		163,155
Contribution from P&C and Corporate and Other	[10]	(177,495)		(125,707)		303,644		(753,168)
Interest expense	[9],[10]	40,798		31,703		121,317		96,147
Non-controlling interests	[10]	57,889		37,583		100,158		77,024
Income tax	[10]	(37,042)		30,057		20,135		58,724
Excluding Life Funds Withheld Assets
Segment Reporting Information [Line Items]
Net investment income	[11]	162,992		153,127		466,302		564,219
Net realized gains (losses) on investments		(201)		9,813		8,752		109,886
Excluding Life Funds Withheld Assets | Corporate and Other
Segment Reporting Information [Line Items]
Net investment income	[10],[11]	10,254		11,552		31,295		134,562
Net realized gains (losses) on investments	[10]	(4)		395		(1,081)		4,297
Life Funds Withheld Assets
Segment Reporting Information [Line Items]
Net investment income		46,586		56,474		143,869		75,639
Net realized gains (losses) on investments		51,608		(5,472)		145,513		(13,619)
Net realized and unrealized gains (losses) on derivative instruments		(126,140)		(201,264)		(116,333)		(218,810)
Life Funds Withheld Assets | Corporate and Other
Segment Reporting Information [Line Items]
Net investment income	[10]	46,586		56,474		143,869		75,639
Net realized gains (losses) on investments	[10]	51,608		(5,472)		145,513		(13,619)
Net realized and unrealized gains (losses) on derivative instruments	[10]	(126,140)		(201,264)		(116,333)		(218,810)
Operating Segments [Member] | Total P&C
Segment Reporting Information [Line Items]
Gross premiums written		2,659,142		1,600,702		8,141,243		6,140,870
Net premiums written		2,073,216		1,214,246		6,010,032		4,567,112
Net premiums earned		2,405,740		1,453,673		5,789,029		4,304,277
Net losses and loss expenses		1,464,285	[1]	859,588		3,385,307	[1]	2,518,973
Acquisition costs		404,444	[1]	180,792		896,256	[1]	553,764
Operating expenses	[2]	422,893		268,918		1,037,733		774,344
Underwriting profit (loss)		114,118		144,375		469,733		457,196
Net results from structured products		4,437	[3]	5,291	[4]	14,719	[5]	48,129	[6]
Net fee income and other	[7]	(4,674)		(3,225)		(12,724)		(6,667)
Net realized and unrealized gains (losses) on derivative instruments						0
Contribution from P&C and Corporate and Other		$ 266,422		$ 297,434		$ 916,568		$ 1,033,904
Ratios - P&C operations
Loss and loss expense ratio	[12]	60.90%		59.10%		58.50%		58.50%
Underwriting expense ratio	[12]	34.40%		31.00%		33.40%		30.90%
Combined ratio	[12]	95.30%		90.10%		91.90%		89.40%
Operating Segments [Member] | Insurance Segment
Segment Reporting Information [Line Items]
Gross premiums written		$ 2,200,196		$ 1,324,418		$ 6,074,387		$ 4,513,749
Net premiums written		1,664,562		956,185		4,155,442		3,080,432
Net premiums earned		1,632,988		1,018,416		4,008,200		3,014,846
Net losses and loss expenses		1,037,727	[1]	650,256		2,551,044	[1]	1,917,076
Acquisition costs		214,773	[1]	95,992		476,876	[1]	300,855
Operating expenses	[2]	334,211		218,281		834,829		635,264
Underwriting profit (loss)		46,277		53,887		145,451		161,651
Net results from structured products		3,328	[3]	3,571	[4]	9,634	[5]	40,106	[6]
Net fee income and other	[7]	$ (5,207)		$ (3,826)		$ (14,705)		$ (8,605)
Ratios - P&C operations
Loss and loss expense ratio	[12]	63.50%		63.80%		63.60%		63.60%
Underwriting expense ratio	[12]	33.70%		30.90%		32.80%		31.00%
Combined ratio	[12]	97.20%		94.70%		96.40%		94.60%
Operating Segments [Member] | Reinsurance Segment
Segment Reporting Information [Line Items]
Gross premiums written		$ 458,946		$ 276,284		$ 2,066,856		$ 1,627,121
Net premiums written		408,654		258,061		1,854,590		1,486,680
Net premiums earned		772,752		435,257		1,780,829		1,289,431
Net losses and loss expenses		426,558	[1]	209,332		834,263	[1]	601,897
Acquisition costs		189,671	[1]	84,800		419,380	[1]	252,909
Operating expenses	[2]	88,682		50,637		202,904		139,080
Underwriting profit (loss)		67,841		90,488		324,282		295,545
Net results from structured products		1,109	[3]	1,720	[4]	5,085	[5]	8,023	[6]
Net fee income and other	[7]	$ 533		$ 601		$ 1,981		$ 1,938
Ratios - P&C operations
Loss and loss expense ratio	[12]	55.20%		48.10%		46.80%		46.70%
Underwriting expense ratio	[12]	36.00%		31.10%		35.00%		30.40%
Combined ratio	[12]	91.20%		79.20%		81.80%		77.10%
Operating Segments [Member] | Excluding Life Funds Withheld Assets | Total P&C
Segment Reporting Information [Line Items]
Net investment income	[11]	$ 152,738		$ 141,575		$ 435,007		$ 429,657
Net realized gains (losses) on investments		$ (197)		$ 9,418		$ 9,833		$ 105,589
[1]	The Company has reflected the amortization of certain fair value adjustments recorded in conjunction with the Catlin Acquisition within the respective segments.
[2]	Operating expenses of the segments exclude Corporate operating expenses, shown separately.
[3]	The net results from P&C structured products include net investment income and interest expense of $15.6 million and $11.1 million, respectively.
[4]	The net results from P&C structured products include net investment income and interest credit of $16.8 million and $11.1 million, respectively.
[5]	The net results from P&C structured products include net investment income and interest expense of $46.7 million and $31.7 million, respectively.
[6]	The net results from P&C structured products include net investment income and interest credit of $52.5 million and $3.7 million, respectively.
[7]	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
[8]	The Company generally records the income related to the hedge fund affiliates and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
[9]	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments
[10]	Corporate and Other includes other items of our revenues and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations.
[11]	Net investment income - excluding Life Funds Withheld Assets does not include net investment income related to the net results from structured products.
[12]	Ratios are based on net premiums earned from P&C operations.

Segment Information - Net Premi

Segment Information - Net Premiums Earned by Line of Business (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net premiums earned by line of business:
P&C Operations		$ 2,405,740	$ 1,453,673	$ 5,789,029	$ 4,304,277
Life Operations		17,812	19,739	50,576	154,568
Total		2,423,552	1,473,412	5,839,605	4,458,845
Corporate and Other
Net premiums earned by line of business:
Life Operations		17,812	19,739	50,576	154,568
Total	[1]	17,812	19,739	50,576	154,568
Professional | Total P&C
Net premiums earned by line of business:
P&C Operations		346,516	314,496	977,508	951,775
Casualty | Total P&C
Net premiums earned by line of business:
P&C Operations		614,912	425,143	1,528,714	1,287,787
Property catastrophe | Total P&C
Net premiums earned by line of business:
P&C Operations		205,337	103,813	462,862	324,812
Property | Total P&C
Net premiums earned by line of business:
P&C Operations		592,175	295,078	1,342,694	855,261
Marine, energy, aviation and satellite | Total P&C
Net premiums earned by line of business:
P&C Operations		36,345	30,511	86,969	75,090
Specialty | Total P&C
Net premiums earned by line of business:
P&C Operations		462,029	186,360	1,014,147	543,217
Other | Total P&C
Net premiums earned by line of business:
P&C Operations	[2]	148,426	98,272	376,135	266,335
Annuity
Net premiums earned by line of business:
Life Operations		0	2	0	53,363
Annuity | Corporate and Other
Net premiums earned by line of business:
Life Operations		0	2	0	53,363
Other life
Net premiums earned by line of business:
Life Operations		17,812	19,737	50,576	101,205
Other life | Corporate and Other
Net premiums earned by line of business:
Life Operations		17,812	19,737	50,576	101,205
Operating Segments [Member] | Total P&C
Net premiums earned by line of business:
Total		2,405,740	1,453,673	5,789,029	4,304,277
Operating Segments [Member] | Insurance Segment
Net premiums earned by line of business:
P&C Operations		1,632,988	1,018,416	4,008,200	3,014,846
Total		1,632,988	1,018,416	4,008,200	3,014,846
Operating Segments [Member] | Reinsurance Segment
Net premiums earned by line of business:
P&C Operations		772,752	435,257	1,780,829	1,289,431
Total		772,752	435,257	1,780,829	1,289,431
Operating Segments [Member] | Professional | Insurance Segment
Net premiums earned by line of business:
P&C Operations		299,639	269,275	852,398	812,211
Operating Segments [Member] | Professional | Reinsurance Segment
Net premiums earned by line of business:
P&C Operations		46,877	45,221	125,110	139,564
Operating Segments [Member] | Casualty | Insurance Segment
Net premiums earned by line of business:
P&C Operations		473,777	358,505	1,203,584	1,061,499
Operating Segments [Member] | Casualty | Reinsurance Segment
Net premiums earned by line of business:
P&C Operations		141,135	66,638	325,130	226,288
Operating Segments [Member] | Property catastrophe | Insurance Segment
Net premiums earned by line of business:
P&C Operations		0	0	0	0
Operating Segments [Member] | Property catastrophe | Reinsurance Segment
Net premiums earned by line of business:
P&C Operations		205,337	103,813	462,862	324,812
Operating Segments [Member] | Property | Insurance Segment
Net premiums earned by line of business:
P&C Operations		320,878	139,663	708,275	422,270
Operating Segments [Member] | Property | Reinsurance Segment
Net premiums earned by line of business:
P&C Operations		271,297	155,415	634,419	432,991
Operating Segments [Member] | Marine, energy, aviation and satellite | Insurance Segment
Net premiums earned by line of business:
P&C Operations		0	0	0	0
Operating Segments [Member] | Marine, energy, aviation and satellite | Reinsurance Segment
Net premiums earned by line of business:
P&C Operations		36,345	30,511	86,969	75,090
Operating Segments [Member] | Specialty | Insurance Segment
Net premiums earned by line of business:
P&C Operations		462,029	186,360	1,014,147	543,217
Operating Segments [Member] | Specialty | Reinsurance Segment
Net premiums earned by line of business:
P&C Operations		0	0	0	0
Operating Segments [Member] | Other | Insurance Segment
Net premiums earned by line of business:
P&C Operations	[2]	76,665	64,613	229,796	175,649
Operating Segments [Member] | Other | Reinsurance Segment
Net premiums earned by line of business:
P&C Operations	[2]	$ 71,761	$ 33,659	$ 146,339	$ 90,686
[1]	Corporate and Other includes other items of our revenues and expenditures that are not evaluated at the segment level for reporting purposes, as well as the Company's Run-Off Life Operations.
[2]	Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines.

Segment Information - Narrative

Segment Information - Narrative (Details) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2015USD ($)		Sep. 30, 2014USD ($)		Sep. 30, 2015USD ($)segments		Sep. 30, 2014USD ($)
Segment Reporting Information [Line Items]
Number of segments | segments					2
Net results from structured products	$ 4,437	[1]	$ 5,291	[2]	$ 14,719	[3]	$ 48,129	[4]
Net investment income | Total P&C
Segment Reporting Information [Line Items]
Net results from structured products	15,600		16,800		46,700		52,500
Interest expense | Total P&C
Segment Reporting Information [Line Items]
Net results from structured products	$ (11,100)		$ (11,100)		$ (31,700)		$ (3,700)
Alternative funds
Segment Reporting Information [Line Items]
Alternative investments, timelag for reporting					1 month
Operating affiliates
Segment Reporting Information [Line Items]
Alternative investments, timelag for reporting					3 months
[1]	The net results from P&C structured products include net investment income and interest expense of $15.6 million and $11.1 million, respectively.
[2]	The net results from P&C structured products include net investment income and interest credit of $16.8 million and $11.1 million, respectively.
[3]	The net results from P&C structured products include net investment income and interest expense of $46.7 million and $31.7 million, respectively.
[4]	The net results from P&C structured products include net investment income and interest credit of $52.5 million and $3.7 million, respectively.

Investments - Cost (amortized c

Investments - Cost (amortized cost for fixed maturities and short-term investments), fair value, gross unrealized gains, gross unrealized (losses), and OTTI recorded in AOCI (Details) - USD ($) $ in Thousands		Sep. 30, 2015		Dec. 31, 2014
Trading securities
Amortized cost of fixed maturities, trading		$ 933,872		$ 1,180
Fixed maturities, trading at fair value		914,337		1,171
AFS securities
Amortized cost of fixed maturities		32,207,019		27,728,771
Fixed maturities, at fair value		33,276,322		29,359,034
Non credit-related OTTI	[1]	(62,804)		(76,720)
Amortized cost of short-term investments, available for sale		545,979		257,221
Short-term investments, at fair value		546,020		256,727
Cost of equity securities		984,192		763,833
Equity securities, at fair value		969,706		868,292
Available for sale securities, Cost or amortized cost		33,737,190		28,749,825
Available for sale securities, Gross unrealized gains		1,380,639		1,947,804
Available for sale securities, Gross unrealized losses		(325,781)		(213,576)
Total investments available for sale		34,792,048		30,484,053
Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		29,144,400		23,427,432
Gross unrealized gains on Fixed maturities		736,522		936,840
Gross unrealized losses on Fixed maturities		(242,961)		(186,803)
Fixed maturities, at fair value		29,637,961		24,177,469
Non credit-related OTTI	[1]	(62,804)		(76,720)
Amortized cost of short-term investments, available for sale		545,979		257,221
Short term investments, gross unrealized gains		1,589		49
Short-term investments, gross unrealized losses		(1,548)		(543)
Short-term investments, at fair value		546,020		256,727
Cost of equity securities		984,192		763,833
Equity securities, gross unrealized gains		66,786		130,689
Equity securities, gross unrealized losses		(81,272)		(26,230)
Equity securities, at fair value		969,706		868,292
Available for sale securities, Cost or amortized cost		30,674,571		24,448,486
Available for sale securities, Gross unrealized gains		804,897		1,067,578
Available for sale securities, Gross unrealized losses		(325,781)		(213,576)
Total investments available for sale		31,153,687		25,302,488
Life Funds Withheld Assets
Trading securities
Amortized cost of fixed maturities, trading		1,004,755		1,180
Fixed maturities, trading at fair value		985,223		1,171
AFS securities
Amortized cost of fixed maturities		3,062,619		4,301,339
Gross unrealized gains on Fixed maturities		575,742		880,226
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		3,638,361		5,181,565
Non credit-related OTTI	[1]	0		0
U.S. Government and Government - Related/Supported | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		4,241,444		2,100,851
Gross unrealized gains on Fixed maturities		72,193		77,889
Gross unrealized losses on Fixed maturities		(14,914)		(6,787)
Fixed maturities, at fair value		4,298,723		2,171,953
Non credit-related OTTI	[1]	0		0
U.S. Government and Government - Related/Supported | Life Funds Withheld Assets
Trading securities
Amortized cost of fixed maturities, trading		4,614
Fixed maturities, trading at fair value		4,610
AFS securities
Amortized cost of fixed maturities		10,998		14,866
Gross unrealized gains on Fixed maturities		2,414		3,858
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		13,412		18,724
Non credit-related OTTI	[1]	0		0
RMBS - Agency | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		3,831,823		3,625,171
Gross unrealized gains on Fixed maturities		100,257		114,188
Gross unrealized losses on Fixed maturities		(8,591)		(10,783)
Fixed maturities, at fair value		3,923,489		3,728,576
Non credit-related OTTI	[1]	0		0
RMBS - Agency | Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		652		3,301
Gross unrealized gains on Fixed maturities		162		481
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		814		3,782
Non credit-related OTTI	[1]	0		0
RMBS - Non-Agency | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		351,793		404,398
Gross unrealized gains on Fixed maturities		27,528		41,108
Gross unrealized losses on Fixed maturities		(16,356)		(18,155)
Fixed maturities, at fair value		362,965		427,351
Non credit-related OTTI	[1]	(55,474)		(67,918)
RMBS - Non-Agency | Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		25,341		71,075
Gross unrealized gains on Fixed maturities		3,492		14,260
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		28,833		85,335
Non credit-related OTTI	[1]	0		0
Commercial mortgage-backed securities | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		837,416		1,033,819
Gross unrealized gains on Fixed maturities		17,642		23,987
Gross unrealized losses on Fixed maturities		(4,974)		(5,262)
Fixed maturities, at fair value		850,084		1,052,544
Non credit-related OTTI	[1]	(1,210)		(2,033)
Commercial mortgage-backed securities | Life Funds Withheld Assets
Trading securities
Amortized cost of fixed maturities, trading		5,002
Fixed maturities, trading at fair value		4,982
AFS securities
Amortized cost of fixed maturities		121,266		168,886
Gross unrealized gains on Fixed maturities		19,900		24,281
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		141,166		193,167
Non credit-related OTTI	[1]	0		0
Collateralized debt obligations | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		419,019		717,544
Gross unrealized gains on Fixed maturities		1,486		1,659
Gross unrealized losses on Fixed maturities		(10,342)		(27,169)
Fixed maturities, at fair value		410,163		692,034
Non credit-related OTTI	[1]	(1,460)		(1,663)
Other asset-backed securities | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		2,072,017	[2]	1,028,528	[3]
Gross unrealized gains on Fixed maturities		34,317	[2]	42,810	[3]
Gross unrealized losses on Fixed maturities		(10,736)	[2]	(6,045)	[3]
Fixed maturities, at fair value		2,095,598	[2]	1,065,293	[3]
Non credit-related OTTI	[1]	(1,351)	[2]	(1,797)	[3]
Other asset-backed securities | Life Funds Withheld Assets
Trading securities
Amortized cost of fixed maturities, trading		20,119
Fixed maturities, trading at fair value		19,872
AFS securities
Amortized cost of fixed maturities		141,774		238,168
Gross unrealized gains on Fixed maturities		21,097		35,373
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		162,871		273,541
Non credit-related OTTI	[1]	0		0
US States and political subdivisions of the States | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		2,536,974		1,892,566
Gross unrealized gains on Fixed maturities		118,345		129,910
Gross unrealized losses on Fixed maturities		(6,649)		(1,204)
Fixed maturities, at fair value		2,648,670		2,021,272
Non credit-related OTTI	[1]	0		0
Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		5,088,447		4,162,425
Gross unrealized gains on Fixed maturities		113,073		139,484
Gross unrealized losses on Fixed maturities		(81,371)		(61,836)
Fixed maturities, at fair value		5,120,149		4,240,073
Non credit-related OTTI	[1]	0		0
Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported | Life Funds Withheld Assets
Trading securities
Amortized cost of fixed maturities, trading		337,249
Fixed maturities, trading at fair value		342,746
AFS securities
Amortized cost of fixed maturities		892,383		1,397,194
Gross unrealized gains on Fixed maturities		248,982		391,842
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		1,141,365		1,789,036
Non credit-related OTTI	[1]	0		0
Financial Services Sector | Corporate | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		3,029,683		2,687,797
Gross unrealized gains on Fixed maturities		60,655		87,058
Gross unrealized losses on Fixed maturities		(17,808)		(12,939)
Fixed maturities, at fair value		3,072,530		2,761,916
Non credit-related OTTI	[1]	0		0
Financial Services Sector | Corporate | Life Funds Withheld Assets
Trading securities
Amortized cost of fixed maturities, trading		228,026
Fixed maturities, trading at fair value		219,767
AFS securities
Amortized cost of fixed maturities		596,259		701,587
Gross unrealized gains on Fixed maturities		73,529		99,432
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		669,788		801,019
Non credit-related OTTI	[1]	0		0
Non-Financial Services Sector | Corporate | Excluding Life Funds Withheld Assets
AFS securities
Amortized cost of fixed maturities		6,735,784	[2]	5,774,333	[3]
Gross unrealized gains on Fixed maturities		191,026	[2]	278,747	[3]
Gross unrealized losses on Fixed maturities		(71,220)	[2]	(36,623)	[3]
Fixed maturities, at fair value		6,855,590	[2]	6,016,457	[3]
Non credit-related OTTI	[1]	(3,309)	[2]	(3,309)	[3]
Non-Financial Services Sector | Corporate | Life Funds Withheld Assets
Trading securities
Amortized cost of fixed maturities, trading		409,745		1,180
Fixed maturities, trading at fair value		393,246		1,171
AFS securities
Amortized cost of fixed maturities		1,273,946		1,706,262
Gross unrealized gains on Fixed maturities		206,166		310,699
Gross unrealized losses on Fixed maturities		0		0
Fixed maturities, at fair value		1,480,112		2,016,961
Non credit-related OTTI	[1]	$ 0		$ 0
[1]	Represents the non-credit component of OTTI losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the date an impairment was recorded.
[2]	Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $74.3 million and an amortized cost of $64.6 million. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes.
[3]	Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $79.9 million and an amortized cost of $68.4 million. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes.

Investments - Contractual matur

Investments - Contractual maturities of available for sale securities (Details) - USD ($) $ in Thousands	Sep. 30, 2015		Dec. 31, 2014
Fixed Maturities - AFS
Amortized cost of fixed maturities	$ 32,207,019		$ 27,728,771
Fixed maturities, at fair value	33,276,322		29,359,034
Trading Securities, Debt, Amortized Cost	933,872		1,180
Trading Securities Debt Maturities And Short Term Investments	914,337		1,171
Excluding Life Funds Withheld Assets
Fixed Maturities - AFS
Due less than one year, amortized cost	2,235,684		1,972,224
Due less than one year, fair value	2,240,138		1,980,429
Due after 1 through 5 years, amortized cost	12,528,098		8,919,037
Due after 1 through 5 years, fair value	12,699,855		9,113,651
Due after 5 through 10 years, amortized cost	5,429,115		4,232,396
Due after 5 through 10 years, fair value	5,518,600		4,412,569
Due after 10 years, amortized cost	1,439,435		1,494,315
Due after 10 years, fair value	1,537,069		1,705,022
Subtotal - amortized cost	21,632,332		16,617,972
Subtotal - fair value	21,995,662		17,211,671
Mortgage and asset backed securities - amortized cost	7,512,068		6,809,460
Mortgage and asset backed securities - fair value	7,642,299		6,965,798
Amortized cost of fixed maturities	29,144,400		23,427,432
Fixed maturities, at fair value	29,637,961		24,177,469
Excluding Life Funds Withheld Assets | RMBS - Agency
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	3,831,823		3,625,171
Mortgage and asset backed securities - fair value	3,923,489		3,728,576
Amortized cost of fixed maturities	3,831,823		3,625,171
Fixed maturities, at fair value	3,923,489		3,728,576
Excluding Life Funds Withheld Assets | RMBS - Non-Agency
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	351,793		404,398
Mortgage and asset backed securities - fair value	362,965		427,351
Amortized cost of fixed maturities	351,793		404,398
Fixed maturities, at fair value	362,965		427,351
Excluding Life Funds Withheld Assets | Commercial mortgage-backed securities
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	837,416		1,033,819
Mortgage and asset backed securities - fair value	850,084		1,052,544
Amortized cost of fixed maturities	837,416		1,033,819
Fixed maturities, at fair value	850,084		1,052,544
Excluding Life Funds Withheld Assets | Collateralized debt obligations
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	419,019		717,544
Mortgage and asset backed securities - fair value	410,163		692,034
Amortized cost of fixed maturities	419,019		717,544
Fixed maturities, at fair value	410,163		692,034
Excluding Life Funds Withheld Assets | Other asset-backed securities
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	2,072,017		1,028,528
Mortgage and asset backed securities - fair value	2,095,598		1,065,293
Amortized cost of fixed maturities	2,072,017	[1]	1,028,528	[2]
Fixed maturities, at fair value	2,095,598	[1]	1,065,293	[2]
Life Funds Withheld Assets
Fixed Maturities - AFS
Due less than one year, amortized cost	93,671		117,048
Due less than one year, fair value	104,481		125,326
Due after 1 through 5 years, amortized cost	441,114		638,526
Due after 1 through 5 years, fair value	472,560		685,787
Due after 5 through 10 years, amortized cost	585,388		1,004,698
Due after 5 through 10 years, fair value	671,738		1,165,348
Due after 10 years, amortized cost	1,653,413		2,059,637
Due after 10 years, fair value	2,055,898		2,649,279
Subtotal - amortized cost	2,773,586		3,819,909
Subtotal - fair value	3,304,677		4,625,740
Mortgage and asset backed securities - amortized cost	289,033		481,430
Mortgage and asset backed securities - fair value	333,684		555,825
Amortized cost of fixed maturities	3,062,619		4,301,339
Fixed maturities, at fair value	3,638,361		5,181,565
Trading Securities, Debt, Amortized Cost	1,004,755		1,180
Trading Securities Debt Maturities And Short Term Investments	985,223		1,171
Life Funds Withheld Assets | RMBS - Agency
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	652		3,301
Mortgage and asset backed securities - fair value	814		3,782
Amortized cost of fixed maturities	652		3,301
Fixed maturities, at fair value	814		3,782
Life Funds Withheld Assets | RMBS - Non-Agency
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	25,341		71,075
Mortgage and asset backed securities - fair value	28,833		85,335
Amortized cost of fixed maturities	25,341		71,075
Fixed maturities, at fair value	28,833		85,335
Life Funds Withheld Assets | Commercial mortgage-backed securities
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	121,266		168,886
Mortgage and asset backed securities - fair value	141,166		193,167
Amortized cost of fixed maturities	121,266		168,886
Fixed maturities, at fair value	141,166		193,167
Trading Securities, Debt, Amortized Cost	5,002
Trading Securities Debt Maturities And Short Term Investments	4,982
Life Funds Withheld Assets | Other asset-backed securities
Fixed Maturities - AFS
Mortgage and asset backed securities - amortized cost	141,774		238,168
Mortgage and asset backed securities - fair value	162,871		273,541
Amortized cost of fixed maturities	141,774		238,168
Fixed maturities, at fair value	162,871		273,541
Trading Securities, Debt, Amortized Cost	20,119
Trading Securities Debt Maturities And Short Term Investments	19,872
Life Funds Withheld Assets | Cost
Fixed Maturities - AFS
Due less than one year	71,135		0
Due after 1 through 5 years	239,984		0
Due after 5 through 10 years	178,020		1,180
Due after 10 years	490,495		0
Subtotal	979,634		1,180
Mortgage and asset-backed securities	25,121		0
Trading Securities, Debt, Amortized Cost	1,004,755		1,180
Life Funds Withheld Assets | Cost | Commercial mortgage-backed securities
Fixed Maturities - AFS
Mortgage and asset-backed securities	5,002		0
Life Funds Withheld Assets | Cost | Other asset-backed securities
Fixed Maturities - AFS
Mortgage and asset-backed securities	20,119		0
Life Funds Withheld Assets | Fair value
Fixed Maturities - AFS
Due less than one year	71,139		0
Due after 1 through 5 years	233,244		0
Due after 5 through 10 years	176,077		1,171
Due after 10 years	479,909		0
Subtotal	960,369		1,171
Mortgage and asset-backed securities	24,854		0
Trading Securities Debt Maturities And Short Term Investments	985,223		1,171
Life Funds Withheld Assets | Fair value | Commercial mortgage-backed securities
Fixed Maturities - AFS
Mortgage and asset-backed securities	4,982		0
Life Funds Withheld Assets | Fair value | Other asset-backed securities
Fixed Maturities - AFS
Mortgage and asset-backed securities	$ 19,872		$ 0
[1]	Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $74.3 million and an amortized cost of $64.6 million. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes.
[2]	Included are certain medium term notes supported primarily by pools of European investment grade credit with varying degrees of leverage. The notes have a fair value of $79.9 million and an amortized cost of $68.4 million. These notes allow the investor to participate in cash flows of the underlying bonds including certain residual values, which could serve to either decrease or increase the ultimate value of these notes.

Investments - Analysis of conti

Investments - Analysis of continual unrealized loss position (Details) - Excluding Life Funds Withheld Assets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Total fixed maturities and short-term investments AFS
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	$ 7,750,972	$ 2,896,210
Less than 12 months Gross Unrealized Losses	(136,075)	(61,772)
Equal to or greater than 12 months Fair Value	1,647,894	2,745,705
Equal to greater than 12 months Gross Unrealized Losses	(108,434)	(125,574)
U.S. Government and Government - Related/Supported
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	1,257,855	251,091
Less than 12 months Gross Unrealized Losses	(10,402)	(1,196)
Equal to or greater than 12 months Fair Value	89,971	342,890
Equal to greater than 12 months Gross Unrealized Losses	(4,524)	(5,603)
RMBS - Agency
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	590,089	134,535
Less than 12 months Gross Unrealized Losses	(3,386)	(220)
Equal to or greater than 12 months Fair Value	237,798	512,652
Equal to greater than 12 months Gross Unrealized Losses	(5,205)	(10,563)
RMBS - Non-Agency
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	28,054	45,378
Less than 12 months Gross Unrealized Losses	(1,022)	(1,358)
Equal to or greater than 12 months Fair Value	206,549	202,700
Equal to greater than 12 months Gross Unrealized Losses	(15,334)	(16,797)
Commercial mortgage-backed securities
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	250,635	78,356
Less than 12 months Gross Unrealized Losses	(2,361)	(385)
Equal to or greater than 12 months Fair Value	87,257	169,065
Equal to greater than 12 months Gross Unrealized Losses	(2,613)	(4,877)
Collateralized debt obligations
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	118,002	249,803
Less than 12 months Gross Unrealized Losses	(286)	(2,666)
Equal to or greater than 12 months Fair Value	194,633	414,516
Equal to greater than 12 months Gross Unrealized Losses	(10,056)	(24,503)
Other asset-backed securities
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	639,048	143,044
Less than 12 months Gross Unrealized Losses	(4,403)	(2,813)
Equal to or greater than 12 months Fair Value	57,445	57,544
Equal to greater than 12 months Gross Unrealized Losses	(6,342)	(3,232)
US States and political subdivisions of the States
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	444,195	32,187
Less than 12 months Gross Unrealized Losses	(5,520)	(210)
Equal to or greater than 12 months Fair Value	17,840	63,695
Equal to greater than 12 months Gross Unrealized Losses	(1,131)	(994)
Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	1,379,798	624,346
Less than 12 months Gross Unrealized Losses	(47,122)	(19,043)
Equal to or greater than 12 months Fair Value	454,537	558,422
Equal to greater than 12 months Gross Unrealized Losses	(34,683)	(43,251)
Equities
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	524,692	191,193
Less than 12 months Gross Unrealized Losses	(81,272)	(26,230)
Equal to or greater than 12 months Fair Value	0	0
Equal to greater than 12 months Gross Unrealized Losses	0	0
Financial Services Sector | Corporate
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	862,043	387,619
Less than 12 months Gross Unrealized Losses	(10,486)	(5,858)
Equal to or greater than 12 months Fair Value	83,008	105,155
Equal to greater than 12 months Gross Unrealized Losses	(7,327)	(7,097)
Non-Financial Services Sector | Corporate
Fixed maturities and short-term investments - AFS:
Less than 12 months Fair Value	2,181,253	949,851
Less than 12 months Gross Unrealized Losses	(51,087)	(28,023)
Equal to or greater than 12 months Fair Value	218,856	319,066
Equal to greater than 12 months Gross Unrealized Losses	$ (21,219)	$ (8,657)

Investments - Analysis of net r

Investments - Analysis of net realized gains (losses) and the change in unrealized (losses) gains on investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net realized gains (losses): [Abstract]
Net realized gains (losses) on investments	$ 51,407	$ 4,341	$ 154,265	$ 96,267
Excluding Life Funds Withheld Assets
Net realized gains (losses): [Abstract]
Gross realized gains	88,224	37,875	199,070	208,035
Gross realized losses on investments sold	(45,711)	(26,918)	(120,440)	(68,662)
OTTI on investments, net of amounts transferred to other comprehensive income	(42,714)	(1,144)	(69,878)	(29,487)
Net realized gains (losses) on investments	(201)	9,813	8,752	109,886
Life Funds Withheld Assets
Net realized gains (losses): [Abstract]
Gross realized gains	60,643	4,511	198,412	5,135
Gross realized losses on investments sold	(6,863)	(2,489)	(23,857)	(2,489)
OTTI on investments, net of amounts transferred to other comprehensive income	(2,023)	(7,494)	(10,110)	(16,265)
Net unrealized gains (losses) on investments, trading securities	(149)	0	(18,932)	0
Net realized gains (losses) on investments	$ 51,608	$ (5,472)	$ 145,513	$ (13,619)

Investments - Credit loss impai

Investments - Credit loss impairments on fixed income securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]
Balance, beginning of period	$ 94,219	$ 165,876	$ 131,942	$ 174,805
Credit loss impairment recognized in the current period on securities not previously impaired	2,004	93	9,565	134
Credit loss impairments previously recognized on securities which matured, paid down, prepaid or were sold during the period	(1,531)	(1,840)	(38,564)	(10,042)
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status	0	0	(2,629)	0
Additional credit loss impairments recognized in the current period on securities previously impaired	945	729	1,331	3,882
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	(2,165)	(2,471)	(8,173)	(6,392)
Balance, end of period	$ 93,472	$ 162,387	$ 93,472	$ 162,387

Investments - Narrative (Detail

Investments - Narrative (Details) $ in Thousands	May. 01, 2014USD ($)	Sep. 30, 2015USD ($)positions	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)positions	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Schedule of Available-for-sale Securities [Line Items]
Change in adjustments related to future policy benefit reserves, net of tax		$ (40,681)	$ (51,286)	$ (127,365)	$ 423,179
Fixed maturities, at fair value		33,276,322		33,276,322		$ 29,359,034
Amortized cost of fixed maturities		$ 32,207,019		$ 32,207,019		$ 27,728,771
Percentage of Fixed Income Investment portfolio invested in below investment grade or not rated		2.10%		2.10%		3.00%
Percentage of Gross Unrealized losses in Fixed income securities portfolio related to securities below investment grade or not rated		15.90%		15.90%		24.90%
Available for sale securities, Gross unrealized losses		$ 325,781		$ 325,781		$ 213,576
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | positions		2,644		2,644
Available-for-sale Securities, Qualitative Disclosure, Number of Positions | positions		8,804		8,804
Pledged Assets Separately Reported, Other Debt Securities Available-for-sale or Held-for-investment		$ 18,800,000		$ 18,800,000		15,200,000
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold		1,531	1,840	38,564	10,042
Corporate
Schedule of Available-for-sale Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities		3,200
Medium term notes
Schedule of Available-for-sale Securities [Line Items]
Fixed maturities, at fair value		74,300		74,300		79,900
Amortized cost of fixed maturities		64,600		64,600		68,400
Structured Credit Securities
Schedule of Available-for-sale Securities [Line Items]
Marketable Securities		30		30
Marketable Securities Unrealized Loss Other Than Temporary Impairments Amount		$ 200		$ 200
Impaired Investment Cumulative Fair Value Decline Percentage Amortized Cost		50.00%		50.00%
RMBS - Non-Agency
Schedule of Available-for-sale Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities		$ 8,000
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold		1,300	900	$ 30,200	6,100
Foreign exchange losses
Schedule of Available-for-sale Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities		19,600
Other investments
Schedule of Available-for-sale Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities		2,200
Government Related Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities		2,000
XL Re Life (SAC) Ltd
Schedule of Available-for-sale Securities [Line Items]
Held To Maturity Securities Transferred Security Carrying Value	$ 2,800,000
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	424,900
Fixed maturites held to maturity, gross unrealized losses	0
Unrealized gains (losses) on investments
Schedule of Available-for-sale Securities [Line Items]
Change in adjustments related to future policy benefit reserves, net of tax				(127,400)
Unrealized gains (losses) on investments | XL Re Life (SAC) Ltd
Schedule of Available-for-sale Securities [Line Items]
Change in adjustments related to future policy benefit reserves, net of tax	$ 440,500
Excluding Life Funds Withheld Assets
Schedule of Available-for-sale Securities [Line Items]
Fixed maturities, at fair value		29,637,961		29,637,961		24,177,469
Amortized cost of fixed maturities		29,144,400		29,144,400		23,427,432
Available for sale securities, Gross unrealized losses		325,781		325,781		213,576
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities		42,714	$ 1,144	69,878	$ 29,487
Excluding Life Funds Withheld Assets | RMBS - Non-Agency
Schedule of Available-for-sale Securities [Line Items]
Fixed maturities, at fair value		362,965		362,965		427,351
Amortized cost of fixed maturities		351,793		$ 351,793		$ 404,398
In A Loss Position For More Than 11 Months | Equities
Schedule of Available-for-sale Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities		4,400
In a Loss Position Greater Than 50% of Amortized Cost | Equities
Schedule of Available-for-sale Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities		$ 3,300

Derivative Instruments - Gross

Derivative Instruments - Gross amounts of derivative fair values contained in the consolidated balance sheet (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Gross amounts recognized in balance sheet		$ 74,115	$ 136,659
Asset derivative fair value		70,215	135,963
Gross amounts recognized in balance sheet		49,710	31,184
Liability derivative fair value		45,810	30,488
Derivatives designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		1,391,228	2,300,609
Gross amounts recognized in balance sheet	[1]	48,774	121,862
Liability derivative notional amount		870,480	302,211
Gross amounts recognized in balance sheet	[1]	20,415	2,936
Derivatives designated as hedging instruments | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		1,391,228	2,300,609
Gross amounts recognized in balance sheet	[1]	48,774	121,862
Liability derivative notional amount		870,480	302,211
Gross amounts recognized in balance sheet	[1]	20,415	2,936
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		677,094	592,791
Gross amounts recognized in balance sheet	[1]	25,341	14,797
Liability derivative notional amount		5,005,831	5,804,625
Gross amounts recognized in balance sheet	[1]	29,295	28,248
Derivatives not designated as hedging instruments | Investment related derivatives | Interest rate exposure
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		21,166	394,597
Gross amounts recognized in balance sheet	[1]	201	206
Liability derivative notional amount		3,222	20,782
Gross amounts recognized in balance sheet	[1]	74	51
Derivatives not designated as hedging instruments | Investment related derivatives | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		377,256	7,385
Gross amounts recognized in balance sheet	[1]	4,767	403
Liability derivative notional amount		68,578	207,182
Gross amounts recognized in balance sheet	[1]	872	4,442
Derivatives not designated as hedging instruments | Investment related derivatives | Credit exposure
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		34,273	2,408
Gross amounts recognized in balance sheet	[1]	729	165
Liability derivative notional amount		46,304	14,270
Gross amounts recognized in balance sheet	[1]	12,196	9,836
Derivatives not designated as hedging instruments | Investment related derivatives | Financial market exposure
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		32,340	46,145
Gross amounts recognized in balance sheet	[1]	3,827	360
Liability derivative notional amount		40,898	33,670
Gross amounts recognized in balance sheet	[1]	1,410	34
Derivatives not designated as hedging instruments | Other non-investment derivatives | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		72,634	0
Gross amounts recognized in balance sheet	[1]	933	0
Liability derivative notional amount		0	81,194
Gross amounts recognized in balance sheet	[1]	0	282
Derivatives not designated as hedging instruments | Other non-investment derivatives | Other credit derivatives
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		30,075	31,060
Gross amounts recognized in balance sheet		141	60
Liability derivative notional amount		0	0
Gross amounts recognized in balance sheet		0	0
Derivatives not designated as hedging instruments | Other non-investment derivatives | Guaranteed minimum income benefit contract
Derivatives, Fair Value [Line Items]
Asset derivative notional amount		48,558	46,249
Gross amounts recognized in balance sheet	[1]	14,743	13,603
Liability derivative notional amount		48,558	46,249
Gross amounts recognized in balance sheet	[1]	14,743	13,603
Derivatives not designated as hedging instruments | Other non-investment derivatives | Modified coinsurance funds withheld contract
Derivatives, Fair Value [Line Items]
Asset derivative notional amount	[2]	60,792	64,947
Gross amounts recognized in balance sheet	[1],[2]	0	0
Liability derivative notional amount	[2]	4,798,271	5,401,278
Gross amounts recognized in balance sheet	[1],[2]	$ 0	$ 0
[1]	Derivative instruments in an asset or liability position are included within Other assets or Other liabilities, respectively, in the balance sheets on a net basis where the Company has both a legal right of offset and the intention to settle the contracts on a net basis.
[2]	The fair value movements in derivative assets and liabilities relating to modified coinsurance funds withheld contracts are included within the associated asset or liability at each period end on the face of the balance sheets. Notional amounts associated with reinsurance agreements under which the Company assumes reinsurance risk are recorded as asset derivative notional amounts. Notional amounts associated with the Life Retro Arrangements under which the Company cedes reinsurance risk are recorded as liability derivative notional amounts. Included in the liability derivative notional amount as of September 30, 2015 is the cumulative net realized and unrealized loss on life retrocession embedded derivative of $468.2 million

Derivative Instruments - Balanc

Derivative Instruments - Balance sheet offsetting (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Derivative assets:
Gross amounts recognized in balance sheet		$ 74,115	$ 136,659
Derivative Asset, Fair Value, Gross Liability	[1]	3,900	696
Net amounts in the balance sheet		70,215	135,963
Gross amounts not offset in the balance sheet - financial instruments		0	0
Gross amounts not offset in the balance sheet - cash collateral		24,000	78,580
Derivative Asset		46,215	57,383
Derivative liabilities:
Gross amounts recognized in balance sheet		49,710	31,184
Derivative Liability, Fair Value, Gross Asset	[1]	3,900	696
Net amounts in the balance sheet		45,810	30,488
Gross amounts not offset in the balance sheet - financial instruments		0	0
Gross amounts not offset in the balance sheet - cash collateral		0	0
Derivative Liability		$ 45,810	$ 30,488
[1]	Other assets and other liabilities include derivative instruments. The derivative balances included in each category are reported on a gross basis by level with a netting adjustment presented separately in the Collateral and Counterparty Netting column. The fair values of the individual derivative contracts are reported gross in their respective levels based on the fair value hierarchy. For further details regarding derivative fair values and associated collateral received or paid, see Note 7, "Derivative Instruments," to the Unaudited Consolidated Financial Statements.

Derivative Instruments - Deriva

Derivative Instruments - Derivatives designated as fair value hedges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income from ineffective portion of fair value hedges	$ 0	$ 0	$ 0	$ (256)
Derivatives designated as hedging instruments | Fair value hedges | Net realized and unrealized gains (losses) on derivative instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income				(15,663)
Amount of gain (loss) recognized in income from ineffective portion of fair value hedges				(256)
Derivatives designated as hedging instruments | Fair value hedges | Net realized and unrealized gains (losses) on derivative instruments | Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income				0
Derivatives designated as hedging instruments | Fair value hedges | Net realized and unrealized gains (losses) on derivative instruments | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income				(15,663)
Derivatives designated as hedging instruments | Fair value hedges | Net realized and unrealized gains (losses) on derivative instruments | Fixed maturity investments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income				$ 15,407

Derivative Instruments - Schedu

Derivative Instruments - Schedule of settlement of fair value hedges (Details) - Fair value hedges - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Notes Payable And Debt [Member]
Derivative [Line Items]
Cumulative reduction to interest expense	$ 0	$ 21,624
Remaining balance	$ 0	$ 0
Weighted average years remaining to maturity	0 years	0 years
Deposit liabilities
Derivative [Line Items]
Cumulative reduction to interest expense	$ 101,461	$ 93,042
Remaining balance	$ 131,734	$ 140,153
Weighted average years remaining to maturity	22 years	23 years 7 months 6 days

Derivative Instruments - Deri63

Derivative Instruments - Derivative instruments designated as hedges of the net investment in a foreign operation - Summary (Details) - Derivatives designated as hedging instruments - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative [Line Items]
Weighted average of U.S. dollar equivalent of foreign denominated net assets		$ 2,299,875	$ 2,052,469	$ 1,581,470	$ 2,336,671
Derivative gains (losses)	[1]	$ 29,943	$ 64,593	$ 66,215	$ 63,383
[1]	Derivative gains (losses) from derivative instruments designated as hedges of the net investment in a foreign operation are recorded in the cumulative translation adjustment account within AOCI for each period.

Derivative Instruments - Net Re

Derivative Instruments - Net Realized and unrealized gains (losses) on derivative instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative [Line Items]
Amount of gain (loss) recognized in income from ineffective portion of fair value hedges	$ 0	$ 0	$ 0	$ (256)
Net realized and unrealized gains (losses) on derivative instruments	(7,903)	5,131	57,127	18,540
Derivatives not designated as hedging instruments
Derivative [Line Items]
Total gain (loss) recognized in income from derivatives not designated as hedging instruments	(7,903)	5,131	57,127	18,796
Derivatives not designated as hedging instruments | Investment related derivatives
Derivative [Line Items]
Interest rate exposure	(5,120)	3,987	(2,046)	13,313
Foreign exchange exposure	(146)	(576)	(1,026)	1,222
Credit exposure	1,684	384	1,380	391
Financial market exposure	(4,309)	(912)	(2,913)	2,467
Derivatives not designated as hedging instruments | Financial operations derivatives
Derivative [Line Items]
Credit exposure	0	915	0	(3,438)
Derivatives not designated as hedging instruments | Other non-investment derivatives
Derivative [Line Items]
Foreign exchange exposure	4,063	0	61,494	0
Credit exposure	(327)	0	1,151	0
Guaranteed minimum income benefit contract	0	0	0	2,257
Modified coinsurance funds withheld contract	(3,748)	1,333	(913)	2,584
Life Funds Withheld Assets
Derivative [Line Items]
Net realized and unrealized gains (losses) on derivative instruments	$ (126,140)	$ (201,264)	$ (116,333)	$ (218,810)

Derivative Instruments - Compon

Derivative Instruments - Components of life retrocession embedded derivative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Derivative [Line Items]
Net realized and unrealized gains (losses) on derivative instruments	$ (7,903)	$ 5,131	$ 57,127	$ 18,540
Life Funds Withheld Assets
Derivative [Line Items]
Net realized and unrealized gains (losses) on life retrocession embedded derivative	(86,849)	(172,077)	(17,355)	(189,623)
Net adjustments related to future policy benefit reserves, net of tax	(40,668)	(18,376)	(88,551)	(18,376)
Net realized and unrealized gains (losses) on derivative instruments - Life Funds Withheld Assets	1,377	(10,811)	(10,427)	(10,811)
Net realized and unrealized gains (losses) on derivative instruments	(126,140)	(201,264)	(116,333)	(218,810)
Life Funds Withheld Assets | Interest income
Derivative [Line Items]
Net realized and unrealized gains (losses) on life retrocession embedded derivative	(48,809)	(59,424)	(147,678)	(79,368)
Life Funds Withheld Assets | Net realized and unrealized gains (losses) on derivative instruments
Derivative [Line Items]
Net realized and unrealized gains (losses) on life retrocession embedded derivative	(38,161)	(113,916)	130,047	(112,023)
Life Funds Withheld Assets | Other income
Derivative [Line Items]
Net realized and unrealized gains (losses) on life retrocession embedded derivative	$ 121	$ 1,263	$ 276	$ 1,768

Derivative Instruments - Summar

Derivative Instruments - Summary of contingent credit features (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Collateral posted to counterparty	$ 0	$ 0
Contracts with downgrade provisions [Member]
Derivative [Line Items]
Aggregate fair value of derivative agreements with downgrade provisions in a net liability position	15,755	5,770
Collateral posted to counterparty	$ 0	$ 0

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014		Dec. 31, 2014
Derivative [Line Items]
Cumulative net realized and unrealized loss on life retrocession embedded derivative		$ 468,200				$ 468,200
Gross amounts recognized in balance sheet		74,115				74,115				$ 136,659
Net realized and unrealized gains (losses) on derivative instruments		(7,903)		$ 5,131		57,127		$ 18,540
Gross amounts not offset in the balance sheet - cash collateral		24,000				24,000				78,580
Net results from structured products		4,437	[1]	5,291	[2]	14,719	[3]	48,129	[4]
Fair value hedges | Deposit liabilities
Derivative [Line Items]
Remaining balance		131,734		$ 140,153		131,734		$ 140,153
Structured indemnity | Fair value hedges | Deposit liabilities
Derivative [Line Items]
Remaining balance		47,000				47,000
Structured indemnity | Interest expense
Derivative [Line Items]
Net results from structured products		28,700
Derivatives not designated as hedging instruments
Derivative [Line Items]
Asset derivative notional amount		677,094				677,094				592,791
Gross amounts recognized in balance sheet	[5]	25,341				25,341				14,797
Other non-investment derivatives | Derivatives not designated as hedging instruments | Other credit derivatives
Derivative [Line Items]
Asset derivative notional amount		30,075				30,075				31,060
Gross amounts recognized in balance sheet		141				$ 141				$ 60
Net realized and unrealized gains (losses) on derivative instruments		$ 100
[1]	The net results from P&C structured products include net investment income and interest expense of $15.6 million and $11.1 million, respectively.
[2]	The net results from P&C structured products include net investment income and interest credit of $16.8 million and $11.1 million, respectively.
[3]	The net results from P&C structured products include net investment income and interest expense of $46.7 million and $31.7 million, respectively.
[4]	The net results from P&C structured products include net investment income and interest credit of $52.5 million and $3.7 million, respectively.
[5]	Derivative instruments in an asset or liability position are included within Other assets or Other liabilities, respectively, in the balance sheets on a net basis where the Company has both a legal right of offset and the intention to settle the contracts on a net basis.

Goodwill and Other Intangible68

Goodwill and Other Intangible Assets - Goodwill and other intangible assets rollforward (Details) - USD ($) $ in Thousands	Jul. 24, 2015	Sep. 30, 2015
Goodwill
Goodwill, beginning of period		$ 415,936
Goodwill acquired during the period		791,433
Foreign currency translation		(3,775)
Goodwill, end of period		1,203,594
Intangible assets with an indefinite life
Intangible assets with an indefinite life, beginning of period		15,366
Indefinite-lived intangible assets acquired during the period		673,000
Intangible assets with an indefinite life, end of period		688,366
Intangible assets with a definite life
Intangible assets with a definite life, beginning of period		16,650
Finite-lived intangible assets acquired during the period		315,000
Amortization		(9,922)
Intangible assets with a definite life, end of period		321,728
Total
Goodwill and other intangible assets, beginning of period		447,952
Additions		1,779,433
Amortization		(9,922)
Foreign currency translation		(3,775)
Goodwill and other intangible assets, end of period		$ 2,213,688
New Energy Risk Inc.
Goodwill
Goodwill acquired during the period	$ 13,400

Goodwill and Other Intangible69

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	May. 01, 2015	Sep. 30, 2015
Schedule Of Acquired Intangible Assets By Major Class [Line Items]
Identified indefinite life intangible assets		$ 673,000
Identified definite life intangible assets		$ 315,000
Catlin Group Limited
Schedule Of Acquired Intangible Assets By Major Class [Line Items]
Identified indefinite life intangible assets	$ 673,000
Identified definite life intangible assets	315,000
Total identified intangible assets	988,000
Catlin Group Limited | Lloyd's - Syndicate capacity
Schedule Of Acquired Intangible Assets By Major Class [Line Items]
Identified indefinite life intangible assets	660,000
Catlin Group Limited | Insurance licenses
Schedule Of Acquired Intangible Assets By Major Class [Line Items]
Identified indefinite life intangible assets	13,000
Catlin Group Limited | Lloyd's - Managing agent contracts
Schedule Of Acquired Intangible Assets By Major Class [Line Items]
Identified definite life intangible assets	15,000
Estimated useful life		15 years
Catlin Group Limited | Distribution network
Schedule Of Acquired Intangible Assets By Major Class [Line Items]
Identified definite life intangible assets	290,000
Estimated useful life		20 years
Catlin Group Limited | Trademarks / Trade names
Schedule Of Acquired Intangible Assets By Major Class [Line Items]
Identified definite life intangible assets	$ 10,000
Estimated useful life		2 years

Share Capital - Summary of ordi

Share Capital - Summary of ordinary shares issued and outstanding (Details) - shares		9 Months Ended	12 Months Ended
		Sep. 30, 2015	Dec. 31, 2014
Summary of ordinary shares issued and outstanding:
Balance, issued, beginning of period (in shares)		255,182,955	278,253,308
Balance, outstanding, beginning of period (in shares)		255,182,955	278,253,000
Exercise of options (in shares)		374,000	424,000
Net issuance of restricted shares (in shares)		1,567,000	1,246,000
Share buybacks (in shares)	[1]	(7,742,000)	(24,740,000)
Issue of shares (in shares)		49,935,000	0
Balance, outstanding, end of period (in shares)		299,317,344	255,182,955
Balance, issued, end of period (in shares)		299,317,344	255,182,955
[1]	Includes share buybacks associated with authorized share buyback programs as well as purchases related to satisfying tax withholding obligations of employees in connection with the vesting of restricted shares granted under the Company's equity compensation programs.

Share Capital - Options valuati

Share Capital - Options valuation assumptions (Details)	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Dividend yield	2.00%
Risk free interest rate	1.70%
Volatility	21.60%
Expected lives	6 years

Share Capital - Narrative (Deta

Share Capital - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	May. 01, 2015	Sep. 30, 2015	Sep. 30, 2015	Aug. 06, 2015	Feb. 21, 2014
2014 Repurchase Authorization
Shareholders Equity Disclosure [Line Items]
Stock Repurchase Program, Authorized Amount					$ 1,000,000
Stock Repurchased and Retired During Period, Shares		1,600,000	4,500,000
Stock Repurchased and Retired During Period, Value		$ 60,000	$ 170,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount				$ 97,600
Two Thousand Fifteen Share Repurchase Authorization
Shareholders Equity Disclosure [Line Items]
Stock Repurchase Program, Authorized Amount				$ 1,000,000
Stock Repurchased and Retired During Period, Shares		3,200,000
Stock Repurchased and Retired During Period, Value		$ 120,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 880,000	$ 880,000
Stock options
Shareholders Equity Disclosure [Line Items]
Weighted Average Grant Date Fair Value Per Stock Option			$ 6.51
Number of Stock Options Granted During the Period			2,000,000
Restricted Stock
Shareholders Equity Disclosure [Line Items]
Number of Awards Granted During the Period			43,457
Aggregate Grant Date Fair Value of Award			$ 1,600
Restricted stock units
Shareholders Equity Disclosure [Line Items]
Number of Awards Granted During the Period			1,500,000
Aggregate Grant Date Fair Value of Award			$ 55,500
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
Deferred Compensation, Share-based Payments
Shareholders Equity Disclosure [Line Items]
Number of Awards Granted During the Period			2,600,000
Aggregate Grant Date Fair Value of Award			$ 94,500
Performance Shares
Shareholders Equity Disclosure [Line Items]
Number of Awards Granted During the Period			800,000
Share Based Compensation Arrangement Performance Units Maximum Share Payout Number			1,600,000
Aggregate Grant Date Fair Value of Award			$ 28,100
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
Minimum
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
Minimum | Performance Shares
Shareholders Equity Disclosure [Line Items]
Performance Units Final Payout Percentage Of Grant Amount			0.00%
Maximum
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			4 years
Maximum | Performance Shares
Shareholders Equity Disclosure [Line Items]
Performance Units Final Payout Percentage Of Grant Amount			200.00%
Catlin Group Limited
Shareholders Equity Disclosure [Line Items]
Share issuance to Catlin shareholders	49,935,000
Share issuance consideration	$ 1,851,601
Preferred Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
Preferred Stock, Liquidation Preference Per Share		$ 1,000	$ 1,000
Preferred Stock, Dividend Rate, Percentage or Spread on Basis			7.249%
Preferred Stock, Value, Outstanding		$ 562,300	$ 562,300
Preferred Stock, Shares Outstanding		600,000	600,000
Three Year Option | Deferred Compensation, Share-based Payments
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
Two Year Option | Deferred Compensation, Share-based Payments
Shareholders Equity Disclosure [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			2 years
3 month LIBOR | Catlin Group Limited
Shareholders Equity Disclosure [Line Items]
Preferred Stock, Dividend Rate, Percentage or Spread on Basis			2.975%

Notes Payable and Debt and Fi73

Notes Payable and Debt and Financing Arrangements - Notes payable and debt (Details) $ in Thousands, € in Millions		Mar. 30, 2015USD ($)	Sep. 30, 2015USD ($)		Sep. 30, 2015EUR (€)	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Commitment, debt			$ 2,763,217			$ 1,675,000
Notes payable and debt			$ 2,726,917			1,662,580
Percentage ownership of subsidiaries			100.00%
Senior notes | 2.3% Senior Notes due 2018
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 300,000			300,000
Notes payable and debt	[2]		$ 297,847			297,344
Debt interest rate (percent)			2.30%		2.30%
Senior notes | 5.75% Senior Notes due 2021
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 400,000			400,000
Notes payable and debt	[2]		$ 397,415			397,092
Debt interest rate (percent)			5.75%		5.75%
Senior notes | 6.375% Senior Notes due 2024
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 350,000			350,000
Notes payable and debt	[2]		$ 349,002			348,920
Debt interest rate (percent)			6.375%		6.375%
Senior notes | 6.25% Senior Notes due 2027
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 325,000			325,000
Notes payable and debt	[2]		$ 323,179			323,062
Debt interest rate (percent)			6.25%		6.25%
Senior notes | 5.25% Senior Notes due 2043
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 300,000			300,000
Notes payable and debt	[2]		$ 296,261			$ 296,162
Debt interest rate (percent)			5.25%		5.25%
XL Cayman | Subordinated notes | 4.45% Subordinated Notes due 2025
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 500,000
Notes payable and debt	[2]		$ 492,318
Debt interest rate (percent)		4.45%	4.45%		4.45%
Debt issue price, as a percentage of face value		99.633%
Net proceeds on issuance of debt		$ 492,200
Debt issuance cost		$ 5,900
XL Cayman | Subordinated notes | 5.5% Subordinated Notes due 2045
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 500,000
Notes payable and debt	[2]		$ 488,271
Debt interest rate (percent)		5.50%	5.50%		5.50%
Debt issue price, as a percentage of face value		99.115%
Net proceeds on issuance of debt		$ 488,400
Debt issuance cost		$ 7,200
Catlin Underwriting | Subordinated notes | Variable Rate Note, face amount EUR 7m due 2035
Debt Instrument [Line Items]
Commitment, debt			$ 7,823	[1]	€ 7
Notes payable and debt	[2]		$ 7,336
Spread on variable rate			2.95%
Catlin Underwriting | Subordinated notes | Variable Rate Note, face amount $27m due 2036
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 27,000
Notes payable and debt	[2]		$ 25,280
Spread on variable rate			3.17%
Catlin Underwriting | Subordinated notes | Variable Rate Note, face amount $31m due 2036
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 31,300
Notes payable and debt	[2]		$ 29,305
Spread on variable rate			3.10%
Catlin Underwriting | Subordinated notes | Variable Rate Note, face amount $10m due 2036
Debt Instrument [Line Items]
Commitment, debt	[1]		$ 9,800
Notes payable and debt	[2]		$ 9,175
Spread on variable rate			3.00%
Catlin Underwriting | Subordinated notes | Variable Rate Note, face amount $11m due 2036
Debt Instrument [Line Items]
Commitment, debt			$ 12,294	[1]	€ 11
Notes payable and debt	[2]		$ 11,528
Spread on variable rate			3.00%
[1]	Excluded from the table are revolving credit facilities of $1.5 billion and $1.6 billion as of September 30, 2015 and December 31, 2014, respectively. As of September 30, 2015 and December 31, 2014, $455.9 million and $606.1 million, respectively, were utilized under these facilities to issue letters of credit, leaving $1.0 billion and $968.9 million, respectively, available for use under the revolving credit facilities.
[2]	"In Use/Outstanding" data represent September 30, 2015 and December 31, 2014 accreted values.

Notes Payable and Debt and Fi74

Notes Payable and Debt and Financing Arrangements - Letter of credit facilities and other sources of collateral (Details) $ in Thousands, AUD in Millions	Sep. 30, 2015USD ($)Credit_Facilities		Sep. 30, 2015AUDCredit_Facilities		Dec. 31, 2014USD ($)Credit_Facilities
Line of Credit Facility [Line Items]
Number of letter of credit facilities available | Credit_Facilities	18		18		8
Revolving credit facility
Line of Credit Facility [Line Items]
Available credit facilities - remaining borrowing capacity	$ 1,039,100	[1],[2],[3]			$ 968,900	[1],[2],[3]
Available letter of credit facilities - commitments	1,500,000				1,600,000
Available letter of credit facilities - in use	455,900				606,100
November 2013 credit agreement
Line of Credit Facility [Line Items]
Available credit facilities - remaining borrowing capacity	976,100				968,900
Available letter of credit facilities - commitments	1,000,000
Letter of credit facilities
Line of Credit Facility [Line Items]
Available letter of credit facilities - commitments	4,850,000	[2],[4]			3,575,000	[2],[4]
Available letter of credit facilities - in use	$ 2,538,499	[2]			$ 1,790,561	[5]
Collateralized by certain assets of the Company’s investment portfolio	49.90%	[2]	49.90%	[2]	66.20%	[2]
2015 Goldman Sachs Facility
Line of Credit Facility [Line Items]
Available letter of credit facilities - commitments	$ 200,000
2013 Citi agreements | Revolving credit facility
Line of Credit Facility [Line Items]
Available letter of credit facilities - commitments	345,000				$ 575,000
2013 Citi agreements | Letter of credit facilities
Line of Credit Facility [Line Items]
Available letter of credit facilities - in use	345,000
Syndicated credit agreements
Line of Credit Facility [Line Items]
Optional increased capacity	500,000
Catlin Group Limited
Line of Credit Facility [Line Items]
Available letter of credit facilities - in use	1,000
Catlin Group Limited | Unsecured multi-bank facility
Line of Credit Facility [Line Items]
Available letter of credit facilities - commitments	450,000
Catlin Group Limited | Letter of credit facilities
Line of Credit Facility [Line Items]
Available letter of credit facilities - in use	10,000
Catlin Group Limited | Bilateral facility
Line of Credit Facility [Line Items]
Available credit facilities - remaining borrowing capacity	63,000
Available letter of credit facilities - commitments	$ 150,000		AUD 50
Number of letter of credit facilities available | Credit_Facilities	2		2
Catlin Bermuda | Bilateral facility
Line of Credit Facility [Line Items]
Available letter of credit facilities - in use	$ 136,000
Catlin Bermuda | LLoyd's syndicate | Bilateral facility
Line of Credit Facility [Line Items]
Available letter of credit facilities - commitments	$ 375,000
Number of letter of credit facilities available | Credit_Facilities	4		4
Catlin Re Switzerland | Bilateral facility
Line of Credit Facility [Line Items]
Available letter of credit facilities - in use	$ 49,000
[1]	As of September 30, 2015 and December 31, 2014, $976.1 million and $968.9 million, respectively, of revolving credit was available under the Company's syndicated unsecured credit agreement, which currently provides for up to $1 billion of revolving credit loans. The Company has the option to increase the size of the facilities under the syndicated secured and unsecured credit agreements by an additional $500 million across both facilities. Two bilateral facilities assumed as a result of the Catlin Acquisition with commitments totaling $150.0 million also provide for revolving credit loans. As of September 30, 2015, $63.0 million of revolving credit was available to draw under these facilities.
[2]	As of September 30, 2015 and December 31, 2014, there were eighteen and eight available letter of credit facilities, respectively.
[3]	The credit agreements with Citicorp USA, Inc. currently provide for the issuance of letters of credit and revolving credit loans up to an aggregate amount of $345.0 million, compared to $575.0 million available under the credit agreements with Citicorp USA, Inc. as of December 31, 2014. As of September 30, 2015, $345.0 million of letters of credit were issued under these agreements, and therefore no amounts are included in this line as available to draw under these facilities. The Company also has the option to increase the maximum amount of the letters of credit and revolving credit loans available under its credit agreements with Citicorp USA, Inc. with the lender's and issuing lender's consent.
[4]	The available letter of credit facilities include approximately $1 billion that is also included in the "revolving credit facilities" line in this table.
[5]	"In Use/Outstanding" data represent September 30, 2015 and December 31, 2014 accreted values.

Related Party Transactions - Sc

Related Party Transactions - Schedule of related party transactions activity (Details) $ in Thousands	Jul. 24, 2015USD ($)	Sep. 30, 2015USD ($)management_company		Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)management_company		Sep. 30, 2014USD ($)	Dec. 31, 2014management_company
Related Party Transaction [Line Items]
Reported net premiums written		$ 2,091,028		$ 1,233,985	$ 6,060,608		$ 4,721,680
Net losses and loss expenses incurred		1,464,285		859,588	3,385,307		2,518,973
Reported acquisition costs		$ 409,173	[1]	182,882	$ 904,486	[1]	566,915
Number of investment management companies | management_company		6			6			6
Investment manager affiliates
Related Party Transaction [Line Items]
Reported net premiums written		$ 5,075		31,981	$ 36,596		68,172
Net losses and loss expenses incurred		1,402		12,738	10,567		27,038
Reported acquisition costs		$ 1,874		$ 10,969	$ 12,269		$ 26,522
New Energy Risk Inc.
Related Party Transaction [Line Items]
Percentage of voting interests acquired	63.63%
Ownership percentage held by noncontrolling interest	5.21%
Cash consideration	$ 8,800
Ownership percentage following additional purchase of shares	94.79%
[1]	The Company has reflected the amortization of certain fair value adjustments recorded in conjunction with the Catlin Acquisition within the respective segments.

Variable Interest Entities (Det

Variable Interest Entities (Details) - Variable Interest Entity, Primary Beneficiary [Member] - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Noncontrolling Interest in Variable Interest Entity	$ 55.8	$ 58.4
Variable Interest Entity, Consolidated, Carrying Amount, Assets	141.5	139.9
New Ocean Capital Management Ltd [Member]
Variable Interest Entity [Line Items]
Noncontrolling Interest in Variable Interest Entity	$ 0.4	$ 0.2

Computation of Earnings Per O77

Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Basic earnings per ordinary share & ordinary share equivalents outstanding:
Net income (loss) attributable to ordinary shareholders	$ 27,282	$ 72,384	$ 978,602	$ 48,841
Weighted average ordinary shares outstanding - basic	301,867	264,353	282,506	270,494
Basic earnings per ordinary share & ordinary share equivalents outstanding	$ 0.09	$ 0.27	$ 3.46	$ 0.18
Diluted earnings per ordinary share & ordinary share equivalents outstanding:
Impact of share-based compensation and certain conversion features	5,087	4,787	4,967	4,418
Weighted average ordinary shares outstanding - diluted (in thousands of shares)	306,954	269,140	287,473	274,912
Diluted earnings per ordinary share & ordinary share equivalents outstanding	$ 0.09	$ 0.27	$ 3.40	$ 0.18
Dividends per ordinary share	$ 0.20	$ 0.16	$ 0.52	$ 0.48

Computation of Earnings Per O78

Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent - Narrative (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based compensation plans
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (shares)	2.6	4.7	2.4	5.5

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015USD ($)Guarantee_contracts	Dec. 31, 2014USD ($)
Guarantor Obligations [Line Items]
Aggregate exposure outstanding	$ 80,800
Total gross claim liability recorded	$ 0	$ 0
Financial Guarantee Insurance Contracts Outstanding Weighted Average Contract Period	24 years 6 months 3 days	25 years 2 months 12 days
Financial Guarantee Related to Securities Including Some Issued By European Financials [Member]
Guarantor Obligations [Line Items]
Closing number of financial guarantee contracts | Guarantee_contracts	2

Accumulated Other Comprehensi80

Accumulated Other Comprehensive Income (Loss) - Changes in AOCI, net of tax (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, net of tax	$ 1,076,174		$ 1,207,034	$ 1,484,458		$ 736,657
OCI before Reclassifications	(28,508)		37,384	(322,827)		656,423
Amounts reclassified from AOCI	(92,063)		(22,547)	(242,696)		(114,253)
Tax benefit (expense)	(521)		10,058	36,147		(46,898)
Comprehensive income (loss)	(121,092)		24,895	(529,376)		495,272
Ending balance, net of tax	955,082		1,231,929	955,082		1,231,929
AOCI Other Details [Abstract]
Change in adjustments related to future policy benefit reserves, net of tax	(40,681)		(51,286)	(127,365)		423,179
Unrealized gains (losses) on investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, net of tax	1,168,964	[1]	1,301,178	1,590,114	[1]	822,432
OCI before Reclassifications	(4,334)	[1]	51,133	(294,341)	[1]	679,732
Amounts reclassified from AOCI	(94,393)	[1]	(28,795)	(256,731)	[1]	(125,770)
Tax benefit (expense)	(2,213)	[1]	7,906	28,982	[1]	(44,972)
Comprehensive income (loss)	(100,940)	[1]	30,244	(522,090)	[1]	508,990
Ending balance, net of tax	1,068,024	[1]	1,331,422	1,068,024	[1]	1,331,422
AOCI Other Details [Abstract]
Change in adjustments related to future policy benefit reserves, net of tax				(127,400)
Cumulative impact on value of future policy benefit reserve, end of period	317,700			317,700			$ 445,100
OTTI losses recognized in AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, net of tax	(64,614)		(84,258)	(76,047)		(89,190)
OCI before Reclassifications	0		0	0		0
Amounts reclassified from AOCI	2,318		6,078	13,916		11,127
Tax benefit (expense)	(181)		(115)	(346)		(232)
Comprehensive income (loss)	2,137		5,963	13,570		10,895
Ending balance, net of tax	(62,477)		(78,295)	(62,477)		(78,295)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, net of tax	(9,508)		1,059	(11,188)		14,541
OCI before Reclassifications	(24,267)		(14,167)	(28,225)		(23,688)
Amounts reclassified from AOCI	0		87	0		87
Tax benefit (expense)	1,873		2,267	7,511		(1,694)
Comprehensive income (loss)	(22,394)		(11,813)	(20,714)		(25,295)
Ending balance, net of tax	(31,902)		(10,754)	(31,902)		(10,754)
Underfunded pension liability
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, net of tax	(21,143)		(13,278)	(20,789)		(13,239)
OCI before Reclassifications	93		418	(261)		379
Amounts reclassified from AOCI	0		0	0		0
Tax benefit (expense)	0		0	0		0
Comprehensive income (loss)	93		418	(261)		379
Ending balance, net of tax	(21,050)		(12,860)	(21,050)		(12,860)
Cash flow hedge
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, net of tax	2,475		2,333	2,368		2,113
OCI before Reclassifications	0		0	0		0
Amounts reclassified from AOCI	12		83	119		303
Tax benefit (expense)	0		0	0		0
Comprehensive income (loss)	12		83	119		303
Ending balance, net of tax	$ 2,487		$ 2,416	$ 2,487		$ 2,416
[1]	Included in these amounts is the impact of Shadow Adjustments as defined in Note 6, "Investments.". As of December 31, 2014 the cumulative impact of the Shadow Adjustments was $445.1 million. During the nine months ended September 30, 2015, net movements of $(127.4) million were recorded, resulting in a total cumulative net impact of Shadow Adjustments on future policy benefit reserves of $317.7 million as of September 30, 2015.

Accumulated Other Comprehensi81

Accumulated Other Comprehensive Income (Loss) - Details About AOCI Components (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	$ (92,063)		$ (22,547)	$ (242,696)		$ (114,253)
Tax benefit (expense)	37,042		(30,057)	(20,135)		(58,724)
Unrealized gains (losses) on investments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(94,393)	[1]	(28,795)	(256,731)	[1]	(125,770)
OTTI losses recognized in AOCI
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	2,318		6,078	13,916		11,127
Accumulated Translation Adjustment [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	0		87	0		87
Underfunded pension liability
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	0		0	0		0
Cash flow hedge
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	12		83	119		303
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(92,063)		(22,547)	(242,696)		(114,253)
Tax benefit (expense)	1,243		953	5,009		4,988
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(90,820)		(21,594)	(237,687)		(109,265)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains (losses) on investments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold	(97,761)		(18,665)	(247,339)		(151,049)
OTTI on investments	44,036		8,246	79,158		43,655
Total before tax	(94,393)		(28,795)	(256,731)		(125,770)
Tax benefit (expense)	1,253		956	5,034		5,108
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(93,140)		(27,839)	(251,697)		(120,662)
Reclassification out of Accumulated Other Comprehensive Income [Member] | OTTI losses recognized in AOCI
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold	1,617		5,686	13,086		9,030
OTTI on investments	701		392	830		2,097
Total before tax	2,318		6,078	13,916		11,127
Tax benefit (expense)	(10)		(3)	(25)		(120)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,308		6,075	13,891		11,007
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Translation Adjustment [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	0		87	0		87
Tax benefit (expense)	0		0	0		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0		87	0		87
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash flow hedge
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	12		83	119		303
Tax benefit (expense)	0		0	0		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	12		83	119		303
Life Funds Withheld Assets
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold	53,780		2,022	174,555		2,646
OTTI on investments	(2,023)		(7,494)	(10,110)		(16,265)
Change in adjustments related to future policy benefit reserves, net of tax	(40,668)		(18,376)	(88,551)		(18,376)
Life Funds Withheld Assets | Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains (losses) on investments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Change in adjustments related to future policy benefit reserves, net of tax	$ (40,668)		$ (18,376)	$ (88,550)		$ (18,376)
[1]	Included in these amounts is the impact of Shadow Adjustments as defined in Note 6, "Investments.". As of December 31, 2014 the cumulative impact of the Shadow Adjustments was $445.1 million. During the nine months ended September 30, 2015, net movements of $(127.4) million were recorded, resulting in a total cumulative net impact of Shadow Adjustments on future policy benefit reserves of $317.7 million as of September 30, 2015.