XL (XLGLF) 10-Q 7 Aug 14 2014 Q2 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	6 Months Ended
	Jun. 30, 2014	Aug. 04, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'XL GROUP PLC	'
Entity Central Index Key	'0000875159	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	265,499,119

UNAUDITED_CONSOLIDATED_BALANCE

UNAUDITED CONSOLIDATED BALANCE SHEETS (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments:	'	'
Fixed maturities, at fair value (amortized cost: 2014, $29,065,531; 2013, $27,111,874)	$30,442,921	$27,500,136
Equity securities, at fair value (cost: 2014, $839,716; 2013, $903,201)	988,710	1,040,237
Short-term investments, at fair value (amortized cost: 2014, $347,473; 2013, $455,470)	347,674	456,288
Total investments available for sale	31,779,305	28,996,661
Fixed maturities, held to maturity at amortized cost (fair value: 2014, $0; 2013, $3,131,235)	0	2,858,695
Investments in affiliates	1,500,548	1,370,943
Other investments	1,204,564	1,164,630
Total investments	34,484,417	34,390,929
Cash and cash equivalents	3,071,139	1,800,832
Accrued investment income	322,100	346,809
Deferred acquisition costs	459,081	670,659
Ceded unearned premiums	1,129,091	788,871
Premiums receivable	3,409,296	2,612,602
Reinsurance balances receivable	149,995	118,885
Unpaid losses and loss expenses recoverable	3,354,273	3,435,230
Receivable from investments sold	59,469	144,765
Goodwill and other intangible assets	455,057	411,611
Deferred tax asset	216,312	237,884
Other assets	738,685	693,810
Total assets	47,848,915	45,652,887
Liabilities:	'	'
Unpaid losses and loss expenses	20,281,934	20,481,065
Deposit liabilities	1,288,376	1,509,243
Future policy benefit reserves	5,273,549	4,803,816
Funds withheld on life retrocession arrangements (net of future policy benefit reserves recoverable:	842,753	0
Unearned premiums	4,704,993	3,846,526
Notes payable and debt	2,262,452	2,263,203
Reinsurance balances payable	779,914	302,399
Payable for investments purchased	169,222	60,162
Deferred tax liability	72,527	86,330
Other liabilities	764,618	950,845
Total liabilities	36,440,338	34,303,589
Commitments and Contingencies	'	'
Shareholders' Equity:	'	'
Ordinary shares, 999,990,000 authorized, par value $0.01; issued and outstanding (2014, 268,307,061; 2013, 278,253,308)	2,683	2,783
Additional paid in capital	7,700,377	7,994,100
Accumulated other comprehensive income	1,207,034	736,657
Retained earnings	1,124,195	1,264,093
Shareholders' equity attributable to XL Group plc	10,034,289	9,997,633
Non-controlling interest in equity of consolidated subsidiaries	1,374,288	1,351,665
Total shareholders' equity	11,408,577	11,349,298
Total liabilities and shareholders' equity	$47,848,915	$45,652,887

UNAUDITED_CONSOLIDATED_BALANCE1

UNAUDITED CONSOLIDATED BALANCE SHEETS (Parentheticals) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Amortized cost of fixed maturities	$29,065,531	$27,111,874
Cost of equity securities	839,716	903,201
Short-term investments, amortized cost	347,473	455,470
Fair value of held to maturity securities	0	3,131,235
Future policy benefit reserves recoverable	$4,823,680	$0
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)	268,307,061	278,253,308
Ordinary shares, shares outstanding (in shares)	268,307,061	278,253,308

UNAUDITED_CONSOLIDATED_STATEME

UNAUDITED CONSOLIDATED STATEMENTS OF INCOME (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues:	'	'	'	'
Net premiums earned	$1,496,594	$1,562,393	$2,985,433	$3,092,084
Net investment income	232,773	232,546	465,962	479,014
Realized investment gains (losses):	'	'	'	'
Net realized gains (losses) on investments	72,697	40,968	91,926	77,477
Net realized and unrealized gains (losses) on derivative instruments	11,599	-5,105	13,409	2,780
Income (loss) from investment fund affiliates	17,683	46,543	50,986	78,764
Fee income and other	9,706	10,871	21,160	20,503
Total revenues	1,823,506	1,888,216	3,611,330	3,750,622
Expenses:	'	'	'	'
Net losses and loss expenses incurred	827,880	937,606	1,659,385	1,780,690
Claims and policy benefits	85,299	116,767	198,886	227,720
Acquisition costs	184,619	231,886	384,033	452,145
Operating expenses	333,030	303,159	643,454	586,991
Exchange (gains) losses	21,141	-11,331	31,582	-44,766
Loss on sale of life reinsurance subsidiary	666,423	0	666,423	0
Interest expense	14,085	38,204	57,026	76,904
Total expenses	2,132,477	1,616,291	3,640,789	3,079,684
Income (loss) before income tax and income (loss) from operating affiliates	-308,971	271,925	-29,459	670,938
Income (loss) from operating affiliates	27,738	32,825	74,023	63,823
Provision (benefit) for income tax	-5,654	28,872	28,667	72,351
Net income (loss)	-275,579	275,878	15,897	662,410
Non-controlling interests	3,682	3,180	39,441	38,922
Net income (loss) attributable to ordinary shareholders	-279,261	272,698	-23,544	623,488
Weighted average ordinary shares and ordinary share equivalents outstanding - basic (in shares)	270,924	289,513	273,616	292,277
Weighted average ordinary shares and ordinary share equivalents outstanding - diluted (in shares)	270,924	294,333	273,616	297,044
Earnings (loss) per ordinary share and ordinary share equivalent - basic (in dollars per share)	($1.03)	$0.94	($0.09)	$2.13
Earnings (loss) per ordinary share and ordinary share equivalent - diluted (in dollars per share)	($1.03)	$0.93	($0.09)	$2.10
Excluding Life Funds Withheld Assets	'	'	'	'
Revenues:	'	'	'	'
Net investment income	213,608	232,546	446,797	479,014
Realized investment gains (losses):	'	'	'	'
Net realized gains (losses) on investments sold	105,460	43,357	128,416	84,504
Other-than-temporary impairments on investments	-24,362	-1,561	-26,638	-5,288
Other-than-temporary impairments on investments transferred to (from) other comprehensive income	-254	-828	-1,705	-1,739
Net realized gains (losses) on investments	80,844	40,968	100,073	77,477
Life Funds Withheld Assets	'	'	'	'
Revenues:	'	'	'	'
Net investment income	19,165	0	19,165	0
Realized investment gains (losses):	'	'	'	'
Net realized gains (losses) on investments sold	624	0	624	0
Other-than-temporary impairments on investments	-8,771	0	-8,771	0
Net realized gains (losses) on investments	-8,147	0	-8,147	0
Net realized and unrealized gains (losses) on derivative instruments	($17,546)	$0	($17,546)	$0

UNAUDITED_CONSOLIDATED_STATEME1

UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net income (loss) attributable to ordinary shareholders	($279,261)	$272,698	($23,544)	$623,488
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	424,861	0	424,861	0
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	10,850	30,076	13,973	25,642
Change in OTTI losses recognized in other comprehensive income, net of tax	1,636	14,438	4,932	19,620
Change in underfunded pension liability, net of tax	-8	-91	-39	295
Change in value of cash flow hedge	110	110	220	220
Foreign currency translation adjustments, net of tax	-9,602	-23,718	-13,482	-27,637
Comprehensive income (loss)	-18,888	-421,665	446,833	-185,773
Unrealized gains (losses) on investments	'	'	'	'
Change in adjustments related to future policy benefit reserves, net of tax	-440,461	-32,900	-474,461	-32,900
Excluding Life Funds Withheld Assets	'	'	'	'
Change in net unrealized gains (losses) on investments, net of tax	260,690	-682,278	502,076	-794,501
Life Funds Withheld Assets	'	'	'	'
Change in net unrealized gains (losses) on investments, net of tax	'	$0	$12,297	$0

UNAUDITED_CONSOLIDATED_STATEME2

UNAUDITED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $)	Total	Ordinary Shares	Additional Paid in Capital	Accumulated Other Comprehensive Income (Loss)	Unrealized gains (losses) on investments	Retained Earnings (Deficit)	Non-controlling Interest in Equity of Consolidated Subsidiaries	Excluding Life Funds Withheld Assets	Excluding Life Funds Withheld Assets	Life Funds Withheld Assets	Life Funds Withheld Assets
In Thousands									Accumulated Other Comprehensive Income (Loss)		Accumulated Other Comprehensive Income (Loss)
Balance, beginning of year at Dec. 31, 2012	'	$2,987	$8,584,752	$1,520,020	'	$402,318	$1,346,325	'	'	'	'
Issuance of ordinary shares	'	11	13	'	'	'	'	'	'	'	'
Buybacks of ordinary shares	'	-129	-360,201	'	'	-15,092	'	'	'	'	'
Exercise of stock options	'	5	'	'	'	'	'	'	'	'	'
Exercise of stock options	'	'	8,380	'	'	'	'	'	'	'	'
Share-based compensation expense	'	'	17,620	'	'	'	'	'	'	'	'
Change in net unrealized gains (losses) on investments, net of tax	'	'	'	'	'	'	'	-794,501	-794,501	0	0
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	'	'	'	-32,900	-32,900	'	'	'	'	'	'
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	25,642	'	'	25,642	'	'	'	'	'	'	'
Change in OTTI losses recognized in other comprehensive income, net of tax	19,620	'	'	19,620	'	'	'	'	'	'	'
Change in underfunded pension liability, net of tax	295	'	'	295	'	'	'	'	'	'	'
Change in value of cash flow hedge	220	'	'	220	'	'	'	'	'	'	'
Foreign currency translation adjustments, net of tax	-27,637	'	'	-27,637	'	'	'	'	'	'	'
Net income (loss) attributable to ordinary shareholders	623,488	'	'	'	'	623,488	'	'	'	'	'
Dividends on ordinary shares	'	'	'	'	'	-82,336	'	'	'	'	'
Non-controlling interests - contribution	'	'	'	'	'	'	0	'	'	'	'
Non-controlling interests - distribution	'	'	'	'	'	'	-37	'	'	'	'
Non-controlling interests	'	'	'	'	'	'	82	'	'	'	'
Non-controlling interest share in change in accumulated other comprehensive income (loss)	'	'	'	'	'	'	-29	'	'	'	'
Non-controlling interests - deconsolidation	'	'	'	'	'	'	-1,841	'	'	'	'
Balance, end of year at Jun. 30, 2013	11,237,075	2,874	8,250,564	710,759	'	928,378	1,344,500	'	'	'	'
Balance, beginning of year at Dec. 31, 2013	11,349,298	2,783	7,994,100	736,657	'	1,264,093	1,351,665	'	'	'	'
Issuance of ordinary shares	'	11	14	'	'	'	'	'	'	'	'
Buybacks of ordinary shares	'	-113	-323,455	'	'	-28,085	'	'	'	'	'
Exercise of stock options	'	2	'	'	'	'	'	'	'	'	'
Exercise of stock options	'	'	3,055	'	'	'	'	'	'	'	'
Share-based compensation expense	'	'	26,663	'	'	'	'	'	'	'	'
Change in net unrealized gains (losses) on investments, net of tax	'	'	'	'	'	'	'	502,076	502,076	12,297	12,297
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	'	'	'	-474,461	-474,461	'	'	'	'	'	'
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	13,973	'	'	13,973	'	'	'	'	'	'	'
Change in OTTI losses recognized in other comprehensive income, net of tax	4,932	'	'	4,932	'	'	'	'	'	'	'
Change in underfunded pension liability, net of tax	-39	'	'	-39	'	'	'	'	'	'	'
Change in value of cash flow hedge	220	'	'	220	'	'	'	'	'	'	'
Foreign currency translation adjustments, net of tax	-13,482	'	'	-13,482	'	'	'	'	'	'	'
Net income (loss) attributable to ordinary shareholders	-23,544	'	'	'	'	-23,544	'	'	'	'	'
Dividends on ordinary shares	'	'	'	'	'	-88,269	'	'	'	'	'
Non-controlling interests - contribution	'	'	'	'	'	'	21,494	'	'	'	'
Non-controlling interests - distribution	'	'	'	'	'	'	0	'	'	'	'
Non-controlling interests	'	'	'	'	'	'	1,129	'	'	'	'
Non-controlling interest share in change in accumulated other comprehensive income (loss)	'	'	'	'	'	'	0	'	'	'	'
Non-controlling interests - deconsolidation	'	'	'	'	'	'	0	'	'	'	'
Balance, end of year at Jun. 30, 2014	$11,408,577	$2,683	$7,700,377	$1,207,034	'	$1,124,195	$1,374,288	'	'	'	'

UNAUDITED_CONSOLIDATED_STATEME3

UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash flows provided by (used in) operating activities:	'	'
Net income (loss)	$15,897	$662,410
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:	'	'
Net realized (gains) losses on investments	-91,926	-77,477
Net realized and unrealized (gains) losses on derivative instruments	-13,409	-2,780
Amortization of premiums (discounts) on fixed maturities	76,846	84,095
(Income) loss from investment and operating affiliates	-68,292	-142,587
Loss on sale of life reinsurance subsidiary	666,423	0
Share-based compensation	40,563	28,400
Depreciation	29,107	23,693
Accretion of deposit liabilities	-7,762	25,467
Changes in:	'	'
Unpaid losses and loss expenses	-264,804	-293,927
Future policy benefit reserves	-93,202	-90,147
Funds withheld on life retrocession agreements, net	-52,104	0
Unearned premiums	848,937	751,455
Premiums receivable	-792,588	-779,737
Unpaid losses and loss expenses recoverable	136,758	95,046
Ceded unearned premiums	-338,855	-222,467
Reinsurance balances receivable	-28,270	-48,420
Deferred acquisition costs	216,453	-74,886
Reinsurance balances payable	420,902	478,012
Deferred tax asset - net	-51,571	-9,476
Derivatives	-45,306	68,445
Other assets	-15,478	-58,729
Other liabilities	-286,737	-60,531
Other	34,501	3,794
Total adjustments	337,732	-302,757
Net cash provided by (used in) operating activities	353,629	359,653
Cash flows provided by (used in) investing activities:	'	'
Proceeds from sale of fixed maturities and short-term investments	3,043,659	2,110,114
Proceeds from redemption of fixed maturities and short-term investments	1,837,319	2,266,692
Proceeds from sale of equity securities	295,448	74,310
Purchases of fixed maturities and short term investments	-3,801,109	-4,108,180
Purchases of equity securities	-239,680	-331,865
Proceeds from sale of affiliates	156,481	95,988
Purchases of affiliates	-196,487	-259,630
Proceeds from sale of life reinsurance subsidiary	570,000	0
Other, net	-96,222	110,133
Net cash provided by (used in) investing activities	1,569,409	-42,438
Cash flows provided by (used in) financing activities:	'	'
Proceeds from issuance of ordinary shares and exercise of stock options	3,057	8,385
Buybacks of ordinary shares	-351,654	-375,423
Dividends paid on ordinary shares	-87,056	-41,975
Distributions to non-controlling interests	-38,502	-39,020
Contributions from non-controlling interests	21,494	0
Deposit liabilities	-213,869	-44,117
Net cash provided by (used in) financing activities	-666,530	-492,150
Effects of exchange rate changes on foreign currency cash	13,799	-23,361
Increase (decrease) in cash and cash equivalents	1,270,307	-198,296
Cash and cash equivalents beginning of year	1,800,832	2,618,378
Cash and cash equivalents end of year	3,071,139	2,420,082
Life Funds Withheld Assets	'	'
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:	'	'
Net realized (gains) losses on investments	8,147	0
Net realized and unrealized (gains) losses on derivative instruments	$17,546	$0

Basis_of_Preparation_and_Conso

Basis of Preparation and Consolidation	6 Months Ended
	Jun. 30, 2014
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.
	These unaudited consolidated financial statements include the accounts of the Company and all of its subsidiaries 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 and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ 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, 2013.
	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_Policie

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Significant Accounting Policies	'
	Significant Accounting Policies
	(a) Investments Related to Life Retrocession Agreements written on a Funds Withheld Basis
	The designated investments that support certain life retrocession agreements written on a funds withheld basis ("Life Funds Withheld Assets") are included within "Total investments available for sale". Investment results for these assets - including interest income, unrealized gains and losses, and gains and losses from sales - are passed directly to the reinsurer pursuant to a contractual arrangement which is accounted for as a derivative. See Note 3, "Sale of Life Reinsurance Subsidiary", for information regarding the reinsurance arrangement.
	Changes in the fair value of the embedded derivative associated with these life retrocession agreements are recorded in “Net realized and unrealized gains (losses) on life retrocession embedded derivative” on the consolidated statements of income. The fair value of the embedded derivative is included within “Funds withheld on life retrocession arrangements, net of future policy benefit reserves recoverable” on the consolidated balance sheets.
	(b) Reinsurance
	The Company enters into reinsurance agreements with other companies in the normal course of business. All balances related to reinsurance agreements are reported on a gross basis on our consolidated balance sheets as an asset for amounts recoverable from reinsurers or as a component of other liabilities for amounts, such as premiums, owed to the reinsurers, with the exception of the life retrocession agreements written on a funds withheld basis. The future policy benefit reserves recoverable related to these retrocession agreements are netted against the funds withheld liability owing to the counterparty on the consolidated balance sheets due to the right of offset.
	(c) Recent Accounting Pronouncements
	In July 2013, the FASB issued an accounting standards update concerning the presentation of unrecognized tax benefits. The objective of the guidance is to improve the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The guidance seeks to reduce the diversity in practice by providing guidance on the presentation of unrecognized tax benefits to better reflect the manner in which an entity would settle, at the reporting date, any additional income taxes that would result from the disallowance of a tax position when net operating loss carryforwards, similar tax losses, or tax credit carryforwards exist. The guidance was effective for annual and interim reporting periods beginning after December 15, 2013, with both early adoption and retrospective application permitted. This guidance did not have a significant impact on the Company's financial condition, results of operations or cash flows.
	In April 2014, the FASB issued an accounting standards update intended to improve financial reporting by changing key criteria used to evaluate whether disposal transactions meet the definition of discontinued operations. Under the guidance only those disposals of components of an entity - either by sale or otherwise - which represent strategic shifts that have, or will have, a major effect on an entity’s operations and financial results would qualify for reporting as discontinued operations. Disposals that are considered to be routine in nature can no longer be reported as discontinued operations. However, a disposal may now qualify for discontinued operations reporting even if the disposed component's operations and cash flows are not eliminated from on-going operations of the disposing entity, or if post-disposal, the disposing entity still has significant continuing involvement in the component’s operations. The standard also establishes both additional disclosure requirements and expanded disclosures regarding on-going involvement an entity may have with a discontinued operation after its disposal. The guidance is effective prospectively for all public company disposals (or component reclassifications to held-for-sale) that occur within annual periods beginning on or after December 15, 2014. Early adoption is permitted, but only for disposals (or component reclassifications to held-for-sale) that have not been reported in financial statements issued or available for issuance prior to the effective date. This guidance is not expected to have a significant impact on the Company's financial condition, results of operations or cash flows.

Sale_of_Life_Reinsurance_Subsi

Sale of Life Reinsurance Subsidiary	6 Months Ended
	Jun. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Sale of Life Reinsurance Subsidiary	'
	Sale of Life Reinsurance Subsidiary
	On May 1, 2014, 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 XL Life Reinsurance (SAC) Ltd (“XLLR”) (subsequent to the transaction XLLR changed its name to GreyCastle Life Reinsurance (SAC) Ltd), a wholly-owned subsidiary of XLIB, to GreyCastle for $570 million in cash. This transaction was completed on May 30, 2014. As a result of the transaction, XLLR reinsures the majority of the Company's life reinsurance business via 100% quota share reinsurance (the "Life Retro Arrangements"). This transaction covers a substantial portion of the Company’s life reinsurance reserves. The Company announced the run-off of its life reinsurance business in 2009.
	The run-off life reinsurance business, including the business subject to the transaction, was previously reported within the Company’s Life operations segment. Subsequent to the transaction, the Company no longer considers the Life Operations to be a separate operating segment and the results of the life run-off business are reported within “Corporate and Other.” See Note 5, "Segment Information" for further information. In addition, certain securities within fixed maturities were reclassified from held to maturity to available for sale in conjunction with this transaction. See Note 6, "Investments" for further information.
	All of the reclassified securities are included within Life Funds Withheld Assets, along with certain other available for sale securities as defined in the sale and purchase agreement. 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 GreyCastle. 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.
	At May 30, 2014, gross future policy benefit reserves relating to the Life operations were approximately $5.2 billion. Subsequent to the completion of this transaction the Company has retained approximately $0.4 billion of these reserves, and has recorded a reinsurance recoverable from XLLR of $4.8 billion. Under the terms of the transaction, the Company continues to own, on a funds withheld basis, $5.7 billion of 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 GreyCastle 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 unaudited consolidated balance sheets.
	The transaction resulted in an overall after-tax U.S. GAAP net loss of $621.3 million. The changes in this amount from the previous estimate provided by the Company were primarily the result of movements in the mark-to-market value of the Life Funds Withheld Assets, additional underwriting profits earned on the business subject to the Life Retro Arrangements and foreign exchange rate movements from March 31, 2014 through completion of the transaction.
	The impact of the Life Retro Arrangements on the Company's results from the completion of the transaction on May 30, 2014 through June 30, 2014 were as follows:
	Impact of Life Retro Arrangements	May 30 to June 30
	(U.S. dollars in thousands)	2014
	Underwriting profit (loss)	$	—
	Net investment income - Life Funds Withheld Assets	19,165
	Net realized gains (losses) on investments sold - Life Funds Withheld Assets	624
	OTTI on investments - Life Funds Withheld Assets	(8,771		)
	Other income and expenses	(19		)
	Net realized and unrealized gains (losses) on life retrocession embedded derivative	(17,546		)
	Net income (loss)	$	(6,547	)
	Change in net unrealized gains (losses) on investments - Life Funds Withheld Assets, net of tax	12,297
	Change in cumulative translation adjustment - Life Funds Withheld Assets, net of tax	(5,750		)
	Comprehensive income (loss)	$	—
	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 no 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	6 Months Ended
	Jun. 30, 2014
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 2(a), “Significant Accounting Policies - Investments Related to Life Retrocession Agreements written on a Funds Withheld Basis,” under the Life Retro Arrangements, all of the investment results associated with the Life Funds Withheld Assets ultimately accrue to GreyCastle. 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 separate the Life Funds Withheld Assets from the rest of the Company's investments.
	For further information, 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, 2013.
	(a) Fair Value Summary
	The following tables set forth the Company’s assets and liabilities that were accounted for at fair value at June 30, 2014 and December 31, 2013 by level within the fair value hierarchy:
	30-Jun-14	Quoted Prices			Significant			Significant			Collateral			Balance at
	(U.S. dollars in thousands)	in Active			Other			Other			and			30-Jun-14
		Markets for			Observable			Unobservable			Counterparty
		Identical Assets			Inputs			Inputs			Netting
		(Level 1)			(Level 2)			(Level 3)
	Assets
	Fixed maturities - Available for Sale ("AFS") - Excluding Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported	$	—		$	2,084,294		$	—		$	—		$	2,084,294
	Corporate (1)	—			9,723,691			3,933			—			9,727,624
	Residential mortgage-backed securities – Agency (“RMBS - Agency”)	—			3,296,150			6,896			—			3,303,046
	Residential mortgage-backed securities – Non-Agency (“RMBS - Non-Agency”)	—			415,492			11			—			415,503
	Commercial mortgage-backed securities (“CMBS”)	—			1,122,342			1,945			—			1,124,287
	Collateralized debt obligations (“CDO”)	—			5,249			732,824			—			738,073
	Other asset-backed securities (2)	—			1,298,568			11,704			—			1,310,272
	U.S. States and political subdivisions of the States	—			1,939,590			—			—			1,939,590
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	—			4,355,861			—			—			4,355,861
	Total fixed maturities - AFS - Excluding Funds Withheld Assets, at fair value	$	—		$	24,241,237		$	757,313		$	—		$	24,998,550
	Equity securities, at fair value (3)	603,993			384,717			—			—			988,710
	Short-term investments, at fair value (1)(4)	—			347,674			—			—			347,674
	Total investments AFS - Excluding Funds Withheld Assets	$	603,993		$	24,973,628		$	757,313		$	—		$	26,334,934
	Fixed maturities - Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported	$	—		$	18,225		$	—		$	—		$	18,225
	Corporate	—			3,017,446			—			—			3,017,446
	RMBS – Agency	—			4,023			—			—			4,023
	RMBS – Non-Agency	—			88,104			—			—			88,104
	CMBS	—			216,844			—			—			216,844
	CDO	—			—			—			—			—
	Other asset-backed securities	—			293,617			—			—			293,617
	U.S. States and political subdivisions of the States	—			—			—			—			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	—			1,806,112			—			—			1,806,112
	Total fixed maturities - AFS - Life Funds Withheld Assets, at fair value	$	—		$	5,444,371		$	—		$	—		$	5,444,371
	Total investments - AFS, at fair value	$	603,993		$	30,417,999		$	757,313		$	—		$	31,779,305
	Cash equivalents (5)	1,792,096			464,544			—			—			2,256,640
	Cash equivalents - Life Funds Withheld Assets	646			122,393			—			—			123,039
	Other investments (6)	—			804,268			124,475			—			928,743
	Other assets (7)	—			48,117			12,453			(1,240		)	59,330
	Total assets accounted for at fair value	$	2,396,735		$	31,857,321		$	894,241		$	(1,240	)	$	35,147,057
	Liabilities
	Financial instruments sold, but not yet purchased (8)	$	1,854		$	29,296		$	—		$	—		$	31,150
	Other liabilities (7)	—			38,277			31,363			(1,240		)	68,400
	Total liabilities accounted for at fair value	$	1,854		$	67,573		$	31,363		$	(1,240	)	$	99,550
	31-Dec-13	Quoted Prices			Significant			Significant			Collateral			Balance at
	(U.S. dollars in thousands)	in Active			Other			Other			and			December 31,
		Markets for			Observable			Unobservable			Counterparty			2013
		Identical Assets			Inputs			Inputs			Netting
		(Level 1)			(Level 2)			(Level 3)
	Assets
	U.S. Government and Government - Related/Supported	$	—		$	2,501,851		$	—		$	—		$	2,501,851
	Corporate (1)	—			11,094,257			31,573			—			11,125,830
	RMBS – Agency	—			3,535,649			10,473			—			3,546,122
	RMBS – Non-Agency	—			398,759			9			—			398,768
	CMBS	—			1,234,262			12,533			—			1,246,795
	CDO	—			7,060			710,253			—			717,313
	Other asset-backed securities (2)	—			1,230,227			11,877			—			1,242,104
U.S. States and political subdivisions of the States	—			1,845,812			—			—			1,845,812
Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	—			4,875,541			—			—			4,875,541
Total fixed maturities, at fair value	$	—		$	26,723,418		$	776,718		$	—		$	27,500,136
Equity securities, at fair value (3)	540,331			499,906			—			—			1,040,237
Short-term investments, at fair value (1)(4)	—			454,273			2,015			—			456,288
Total investments available for sale	$	540,331		$	27,677,597		$	778,733		$	—		$	28,996,661
Cash equivalents (5)	834,514			226,636			—			—			1,061,150
Other investments (6)	—			757,110			113,472			—			870,582
Other assets (7)	—			27,487			—			(1,342		)	26,145
Total assets accounted for at fair value	$	1,374,845		$	28,688,830		$	892,205		$	(1,342	)	$	30,954,538
Liabilities
Financial instruments sold, but not yet purchased (8)	$	—		$	28,861		$	—		$	—		$	28,861
Other liabilities (7)	—			76,375			29,110			(1,342		)	104,143
Total liabilities accounted for at fair value	$	—		$	105,236		$	29,110		$	(1,342	)	$	133,004
____________
-1	Included within Corporate 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 $155.9 million and $154.6 million and an amortized cost of $143.6 million and $147.7 million at June 30, 2014 and December 31, 2013, 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	The Company invests in covered bonds (“Covered Bonds”). Covered Bonds are senior secured debt instruments issued by financial institutions and backed by over-collateralized pools of public sector or mortgage loans. At June 30, 2014 and December 31, 2013, Covered Bonds with a fair value of $763.6 million and $553.1 million, respectively, are included within Other asset-backed securities.
-3	Included within Equity securities are investments in fixed income funds with a fair value of $92.1 million and $87.4 million at June 30, 2014 and December 31, 2013, respectively.
-4	Short-term investments consist primarily of Corporate securities and U.S. and Non-U.S. Government and Government-Related/Supported securities.
-5	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.
-6	The Other investments balance excludes certain structured transactions including certain investments in project finance transactions, 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 $275.8 million at June 30, 2014 and $294.0 million at December 31, 2013, are carried at amortized cost. For further information, see Item 8, Note 7, “Other Investments,” to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2013.
-7	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.
-8	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 six months ended June 30, 2014 and 2013 for all financial assets and liabilities measured at fair value using significant unobservable inputs (Level 3) at June 30, 2014 and 2013, 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 June 30, 2014 and 2013. 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 and other valuations sourced from brokers that are considered Level 3.
There were no significant transfers between Level 1 and Level 2 during the three and six months ended June 30, 2014 and 2013.
	Level 3 Assets and Liabilities -Three Months Ended June 30, 2014
(U.S. dollars in thousands)	Corporate			RMBS - Agency			RMBS - Non			CMBS			CDO
							Agency
Balance, beginning of period	$	4,382		$	8,928		$	11		$	5,926		$	718,827
Realized gains (losses)	35			6			—			2			875
Movement in unrealized gains (losses)	(93		)	(13		)	—			(1		)	8,331
Purchases and issuances	8			—			—			1,376			75,201
Sales	—			—			—			—			(30,892		)
Settlements	(399		)	(2,025		)	—			(5,358		)	(39,518		)
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	—			—			—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	3,933		$	6,896		$	11		$	1,945		$	732,824
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	(58	)	$	(6	)	$	—		$	—		$	8,247
	Level 3 Assets and Liabilities -Three Months Ended June 30, 2014
(U.S. dollars in thousands)	Other asset-			Non-US Sovereign			Short-term			Other investments			Derivative Contracts
	backed			Government,			investments						- Net
	securities			Provincial,
				Supranational and
				Government
				Related/Supported
Balance, beginning of period	$	10,673		$	—		$	—		$	116,418		$	(32,496	)
Realized gains (losses)	(5		)	—			—			5,127			—
Movement in unrealized gains (losses)	144			—			—			(1,779		)	13,586
Purchases and issuances	3,000			—			—			9,997			—
Sales	—			—			—			—			—
Settlements	(2,108		)	—			—			(5,288		)	—
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	—			—			—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	11,704		$	—		$	—		$	124,475		$	(18,910	)
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	140		$	—		$	—		$	3,348		$	13,586
	Level 3 Assets and Liabilities -Three Months Ended June 30, 2013
(U.S. dollars in thousands)	Corporate			RMBS - Agency			RMBS - Non			CMBS			CDO
							Agency
Balance, beginning of period	$	40,815		$	19,107		$	103		$	25,012		$	702,904
Realized gains (losses)	(69		)	(2		)	—			—			(55		)
Movement in unrealized gains (losses)	426			(19		)	—			(19		)	14,491
Purchases and issuances	—			—			3,326			—			5,362
Sales	—			—			—			—			—
Settlements	(7,139		)	(872		)	(18		)	(570		)	(16,689		)
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	(1,860		)	—			—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	32,173		$	18,214		$	3,411		$	24,423		$	706,013
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	424		$	(22	)	$	(1	)	$	(19	)	$	13,804
	Level 3 Assets and Liabilities -Three Months Ended June 30, 2013
(U.S. dollars in thousands)	Other asset-			Non-US Sovereign			Short-term			Other investments			Derivative Contracts
	backed			Government,			investments						- Net
	securities			Provincial,
				Supranational and
				Government
				Related/Supported
Balance, beginning of period	$	35,887		$	—		$	2,017		$	113,322		$	(32,550	)
Realized gains (losses)	(13		)	—			(10		)	2,872			—
Movement in unrealized gains (losses)	(512		)	—			(8		)	932			3,176
Purchases and issuances	—			—			—			1,002			—
Sales	—			—			—			—			—
Settlements	(1,317		)	—			—			(14,284		)	—
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	(6,506		)	—			—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	27,539		$	—		$	1,999		$	103,844		$	(29,374	)
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	(525	)	$	—		$	(18	)	$	3,812		$	3,176
	Level 3 Assets and Liabilities - Six Months Ended June 30, 2014
(U.S. dollars in thousands)	Corporate			RMBS - Agency			RMBS - Non			CMBS			CDO
							Agency
Balance, beginning of period	$	31,573		$	10,473		$	9		$	12,533		$	710,253
Realized gains (losses)	155			6			—			3			2,456
Movement in unrealized gains (losses)	(96		)	(13		)	2			(3		)	12,013
Purchases and issuances	1,443			—			—			1,376			103,015
Sales	—			—			—			—			(40,824		)
Settlements	(5,513		)	(2,598		)	—			(11,964		)	(54,089		)
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	(23,629		)	(972		)	—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	3,933		$	6,896		$	11		$	1,945		$	732,824
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	90		$	(6	)	$	2		$	—		$	13,216
	Level 3 Assets and Liabilities - Six Months Ended June 30, 2014
(U.S. dollars in thousands)	Other asset-			Non-US Sovereign			Short-term			Other investments			Derivative Contracts
	backed			Government,			investments						- Net
	securities			Provincial,
				Supranational and
				Government
				Related/Supported
Balance, beginning of period	$	11,877		$	—		$	2,015		$	113,472		$	(29,110	)
Realized gains (losses)	(20		)	—			—			8,691			—
Movement in unrealized gains (losses)	206			—			(15		)	(282		)	10,200
Purchases and issuances	3,000			—			—			21,086			—
Sales	—			—			—			—			—
Settlements	(3,359		)	—			(2,000		)	(18,492		)	—
Transfers into Level 3	—			—						—			—
Transfers out of Level 3	—			—			—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	11,704		$	—		$	—		$	124,475		$	(18,910	)
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	186		$	—		$	—		$	8,409		$	10,200
	Level 3 Assets and Liabilities - Six Months Ended June 30, 2013
(U.S. dollars in thousands)	Corporate			RMBS - Agency			RMBS - Non			CMBS			CDO
							Agency
Balance, beginning of period	$	30,098		$	32,005		$	116		$	25,347		$	701,736
Realized gains (losses)	(71		)	11			—			—			301
Movement in unrealized gains (losses)	630			(37		)	—			(18		)	35,746
Purchases and issuances	10,621			—			3,326			—			5,362
Sales	—			(535		)	—			—			—
Settlements	(7,245		)	(1,765		)	(31		)	(906		)	(37,132		)
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	(1,860		)	(11,465		)	—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	32,173		$	18,214		$	3,411		$	24,423		$	706,013
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	627		$	(40	)	$	(1	)	$	(18	)	$	34,278
	Level 3 Assets and Liabilities - Six Months Ended June 30, 2013
(U.S. dollars in thousands)	Other asset-			Non-US Sovereign			Short-term			Other investments			Derivative Contracts
	backed			Government,			investments						- Net
	securities			Provincial,
				Supranational and
				Government
				Related/Supported
Balance, beginning of period	$	18,128		$	—		$	—		$	115,272		$	(36,247	)
Realized gains (losses)	38			—			(10		)	5,787			—
Movement in unrealized gains (losses)	963			—			(8		)	(970		)	6,873
Purchases and issuances	21,686			—			2,017			2,907			—
Sales	—			—			—			—			—
Settlements	(6,770		)	—			—			(19,152		)	—
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	(6,506		)	—			—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	27,539		$	—		$	1,999		$	103,844		$	(29,374	)
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	(516	)	$	—		$	(18	)	$	4,808		$	6,873
(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 alternative 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. Investments in alternative funds included in Other investments utilize strategies including arbitrage, directional, event driven and multi-style. These funds potentially have lockup and gate provisions which may limit redemption liquidity. For further details regarding the nature of Other investments and related features see Item 8, Note 7, “Other Investments,” to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013.
(e) Derivative instruments
Derivative instruments recorded within Other liabilities and classified within Level 3 include credit derivatives sold 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 the interest income, 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 the “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 at June 30, 2014 and December 31, 2013. All of these fair value estimates are considered Level 2 fair value measurements. The fair values for fixed maturities held to maturity are provided by third party pricing vendors and significant valuation inputs for all other items included were based upon market data obtained from sources independent of the Company, and are subject to the same control environment previously described.
	June 30, 2014						December 31, 2013
(U.S. dollars in thousands)	Carrying			Fair			Carrying			Fair
	Value			Value			Value			Value
Fixed maturities, held to maturity	$	—		$	—		$	2,858,695		$	3,131,235
Other investments - structured transactions	275,821			299,661			294,048			296,799
Financial Assets	$	275,821		$	299,661		$	3,152,743		$	3,428,034
Deposit liabilities	$	1,288,376		$	1,520,108		$	1,509,243		$	1,718,394
Notes payable and debt	2,262,452			2,511,270			2,263,203			2,429,412
Financial Liabilities	$	3,550,828		$	4,031,378		$	3,772,446		$	4,147,806
As described in Note 3, "Sale of Life Reinsurance Subsidiary," certain fixed maturities were reclassified from held to maturity to available for sale. See also Note 6, "Investments" for further information.
The Company historically participated in structured transactions. Remaining structured transactions include cash loans supporting project finance transactions, 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 45.5 basis points and 56.7 basis points at June 30, 2014 and December 31, 2013, 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	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	The Company is organized into two operating segments: Insurance and Reinsurance. Subsequent to the transaction as described in Note 3, "Sale of Life Reinsurance Subsidiary", XLLR reinsures the majority of the Company's life reinsurance business through the Life Retro Arrangements. The Company no longer considers the Life Operations to be a separate operating segment and the results of the life run-off business are reported within “Corporate and Other.” The Company’s general investment and financing operations are also reflected in Corporate and Other. The run-off business subject to the Life Retro Arrangements was previously reported within the Company’s Life operations segment. Prior period information has been re-presented to reflect the current presentation.
	The Company evaluates the performance of both the Insurance and Reinsurance segments based on underwriting profit. Other items of revenue and expenditure 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. The following tables summarize the segment results for the three and six months ended June 30, 2014 and 2013:
	Three Months Ended June 30, 2014	Insurance			Reinsurance			Total P&C			Corporate			Total
	(U.S. dollars in thousands, except ratios)										and Other (1)
	Gross premiums written	$	1,618,405		$	493,124		$	2,111,529		$	86,710		$	2,198,239
	Net premiums written	996,880			436,446			1,433,326			58,518			1,491,844
	Net premiums earned	1,003,990			434,086			1,438,076			58,518			1,496,594
	Net losses and loss expenses	627,627			200,253			827,880			85,299			913,179
	Acquisition costs	99,863			80,874			180,737			3,882			184,619
	Operating expenses (2)	213,931			47,582			261,513			2,209			263,722
	Underwriting profit (loss)	$	62,569		$	105,377		$	167,946		$	(32,872	)	$	135,074
	Net investment income - excluding Life Funds Withheld Assets							144,555			52,118			196,673
	Net investment income - Life Funds Withheld Assets										19,165			19,165
	Net results from structured products (3)	31,645			3,240			34,885			—			34,885
	Net fee income and other (4)	(3,567		)	664			(2,903		)	45			(2,858		)
	Loss on sale of life reinsurance subsidiary							—			666,423			666,423
	Net realized gains (losses) on investments - excluding Life Funds Withheld Assets							78,505			2,339			80,844
	Net realized gains (losses) on investments - Life Funds Withheld Assets							—			(8,147		)	(8,147		)
	Net realized and unrealized gains (losses) on derivative instruments							—			11,599			11,599
	Net realized and unrealized gains (losses) on life retrocession embedded derivative							—			(17,546		)	(17,546		)
	Net income (loss) from investment fund affiliates and operating affiliates (5)							—			45,421			45,421
	Exchange (gains) losses							—			21,141			21,141
	Corporate operating expenses							—			56,495			56,495
	Contribution from P&C and Corporate and Other							422,988			(671,937		)	(248,949		)
	Interest expense (6)										32,284			32,284
	Non-controlling interests										3,682			3,682
	Income tax expense										(5,654		)	(5,654		)
	Net income (loss) attributable to ordinary shareholders													$	(279,261	)
	Ratios – P&C operations: (7)
	Loss and loss expense ratio	62.5		%	46.1		%	57.6		%
	Underwriting expense ratio	31.3		%	29.6		%	30.7		%
	Combined ratio	93.8		%	75.7		%	88.3		%
	____________
	-1	Corporate and Other includes the Company's run-off life operations.
	-2	Operating expenses exclude Corporate operating expenses, shown separately.
	-3	The net results from structured products include net investment income and interest expense (credit) of $16.9 million and $(18.2) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
	-4	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
	-5	The Company records the income related to the alternative funds and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
	-6	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments.
	-7	Ratios are based on net premiums earned from P&C operations.
	Three Months Ended June 30, 2013	Insurance			Reinsurance			Total P&C			Corporate			Total
	(U.S. dollars in thousands, except ratios)										and Other (1)
	Gross premiums written	$	1,472,388		$	471,782		$	1,944,170		$	81,302		$	2,025,472
	Net premiums written	1,049,163			410,809			1,459,972			73,896			1,533,868
	Net premiums earned	1,058,542			429,955			1,488,497			73,896			1,562,393
	Net losses and loss expenses	721,323			216,283			937,606			116,767			1,054,373
	Acquisition costs	138,032			86,599			224,631			7,255			231,886
	Operating expenses (2)	194,514			39,622			234,136			2,206			236,342
	Underwriting profit (loss)	$	4,673		$	87,451		$	92,124		$	(52,332	)	$	39,792
	Net investment income - excluding Life Funds Withheld Assets							143,818			70,592			214,410
	Net investment income - Life Funds Withheld Assets										—			—
	Net results from structured products (3)	3,532			2,521			6,053			—			6,053
	Net fee income and other (4)	(1,355		)	520			(835		)	44			(791		)
	Loss on sale of life reinsurance subsidiary							—			—			—
	Net realized gains (losses) on investments - excluding Life Funds Withheld Assets							29,369			11,599			40,968
	Net realized gains (losses) on investments - Life Funds Withheld Assets							—			—			—
	Net realized and unrealized gains (losses) on derivative instruments							—			(5,105		)	(5,105		)
	Net realized and unrealized gains (losses) on life retrocession embedded derivative							—			—			—
	Net income (loss) from investment fund affiliates and operating affiliates (5)							—			79,368			79,368
	Exchange (gains) losses							—			(11,331		)	(11,331		)
	Corporate operating expenses							—			55,155			55,155
	Contribution from P&C and Corporate and Other							270,529			60,342			330,871
Interest expense (6)										26,121			26,121
Non-controlling interests										3,180			3,180
Income tax expense										28,872			28,872
Net income (loss) attributable to ordinary shareholders													$	272,698
Ratios – P&C operations: (7)
Loss and loss expense ratio	68.1		%	50.3		%	63		%
Underwriting expense ratio	31.5		%	29.4		%	30.8		%
Combined ratio	99.6		%	79.7		%	93.8		%
____________
-1	Corporate and Other includes the Company's run-off life operations.
-2	Operating expenses exclude Corporate operating expenses, shown separately.
-3	The net results from structured products include net investment income and interest expense of $18.1 million and $12.1 million, respectively.
-4	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
-5	The Company records the income related to the alternative funds and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
-6	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments.
-7	Ratios are based on net premiums earned from P&C operations.
Six Months Ended June 30, 2014	Insurance			Reinsurance			Total P&C			Corporate			Total
(U.S. dollars in thousands, except ratios)										and Other (1)
Gross premiums written	$	3,189,331		$	1,350,837		$	4,540,168		$	171,007		$	4,711,175
Net premiums written	2,124,247			1,228,619			3,352,866			134,829			3,487,695
Net premiums earned	1,996,430			854,174			2,850,604			134,829			2,985,433
Net losses and loss expenses	1,266,820			392,565			1,659,385			198,886			1,858,271
Acquisition costs	204,863			168,109			372,972			11,061			384,033
Operating expenses (2)	416,984			88,443			505,427			5,397			510,824
Underwriting profit (loss)	$	107,763		$	205,057		$	312,820		$	(80,515	)	$	232,305
Net investment income - excluding Life Funds Withheld Assets							288,082			123,010			411,092
Net investment income - Life Funds Withheld Assets										19,165			19,165
Net results from structured products (3)	36,535			6,303			42,838			—			42,838
Net fee income and other (4)	(4,779		)	1,337			(3,442		)	90			(3,352		)
Loss on sale of life reinsurance subsidiary							—			666,423			666,423
Net realized gains (losses) on investments - excluding Life Funds Withheld Assets							96,171			3,902			100,073
Net realized gains (losses) on investments - Life Funds Withheld Assets							—			(8,147		)	(8,147		)
Net realized and unrealized gains (losses) on derivative instruments							—			13,409			13,409
Net realized and unrealized gains (losses) on life retrocession embedded derivative							—			(17,546		)	(17,546		)
Net income (loss) from investment fund affiliates and operating affiliates (5)							—			125,009			125,009
Exchange (gains) losses							—			31,582			31,582
Corporate operating expenses							—			107,833			107,833
Contribution from P&C and Corporate and Other							$	736,469		$	(627,461	)	$	109,008
Interest expense (6)										64,444			64,444
Non-controlling interests										39,441			39,441
Income tax expense										28,667			28,667
Net income (loss) attributable to ordinary shareholders													$	(23,544	)
Ratios – P&C operations: (7)
Loss and loss expense ratio	63.5		%	46		%	58.2		%
Underwriting expense ratio	31.1		%	30		%	30.8		%
Combined ratio	94.6		%	76		%	89		%
____________
-1	Corporate and Other includes the Company's run-off life operations.
-2	Operating expenses exclude Corporate operating expenses, shown separately.
-3	The net results from structured products include net investment income and net interest expense (credit) of $35.7 million and $(7.4) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
-4	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
-5	The Company records the income related to the alternative funds and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
-6	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments.
-7	Ratios are based on net premiums earned from P&C operations.
Six Months Ended June 30, 2013	Insurance			Reinsurance			Total P&C			Corporate			Total
(U.S. dollars in thousands, except ratios)										and Other (1)
Gross premiums written	$	2,970,175		$	1,378,911		$	4,349,086		$	154,272		$	4,503,358
Net premiums written	2,238,351			1,263,830			3,502,181			139,341			3,641,522
Net premiums earned	2,097,634			855,109			2,952,743			139,341			3,092,084
Net losses and loss expenses	1,371,840			408,850			1,780,690			227,720			2,008,410
Acquisition costs	268,654			172,133			440,787			11,358			452,145
Operating expenses (2)	378,511			80,043			458,554			4,801			463,355
Underwriting profit (loss)	$	78,629		$	194,083		$	272,712		$	(104,538	)	$	168,174
Net investment income - excluding Life Funds Withheld Assets							300,857			142,280			443,137
Net investment income - Life Funds Withheld Assets										—			—
Net results from structured products (3)	7,717			3,512			11,229			—			11,229
Net fee income and other (4)	(3,294		)	1,152			(2,142		)	1,087			(1,055		)
Loss on sale of life reinsurance subsidiary							—			—			—
Net realized gains (losses) on investments - excluding Life Funds Withheld Assets							74,947			2,530			77,477
Net realized gains (losses) on investments - Life Funds Withheld Assets							—			—			—
Net realized and unrealized gains (losses) on derivative instruments							—			2,780			2,780
Net realized and unrealized gains (losses) on life retrocession embedded derivative							—			—			—
Net income (loss) from investment fund affiliates and operating affiliates (5)							—			142,587			142,587
Exchange (gains) losses							—			(44,766		)	(44,766		)
Corporate operating expenses							—			102,077			102,077
Contribution from P&C and Corporate and Other							$	657,603		$	129,415		$	787,018
Interest expense (6)										52,257			52,257
Non-controlling interests										38,922			38,922
Income tax expense										72,351			72,351
Net income (loss) attributable to ordinary shareholders													$	623,488
Ratios – P&C operations: (7)
Loss and loss expense ratio	65.4		%	47.8		%	60.3		%
Underwriting expense ratio	30.9		%	29.5		%	30.5		%
Combined ratio	96.3		%	77.3		%	90.8		%
____________
-1	Corporate and Other includes the Company's run-off life operations.
-2	Operating expenses exclude Corporate operating expenses, shown separately.
-3	The net results from structured products include net investment income and interest expense of $35.9 million and $24.6 million, respectively.
-4	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
-5	The Company records the income related to the alternative funds and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
-6	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments.
-7	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 months ended June 30, 2014 and 2013:
Three Months Ended June 30, 2014	Insurance			Reinsurance			Corporate			Total
(U.S. dollars in thousands)							and Other
P&C Operations:
Professional	$	267,509		$	44,239		$	—		$	311,748
Casualty	358,990			82,929			—			441,919
Property catastrophe	—			112,562			—			112,562
Property	142,874			142,337			—			285,211
Marine, energy, aviation and satellite	—			21,065			—			21,065
Specialty	179,948			—			—			179,948
Other (1)	54,669			30,954			—			85,623
Total P&C Operations	$	1,003,990		$	434,086		$	—		$	1,438,076
Corporate and Other:
Run-off Life operations - Annuity	$	—		$	—		$	21,565		$	21,565
Run-off Life operations - Other Life	—			—			36,953			36,953
Total Corporate and Other	$	—		$	—		$	58,518		$	58,518
Total	$	1,003,990		$	434,086		$	58,518		$	1,496,594
Three Months Ended June 30, 2013	Insurance			Reinsurance			Corporate			Total
(U.S. dollars in thousands)							and Other
P&C Operations:
Professional	$	349,812		$	50,978		$	—		$	400,790
Casualty	338,437			76,544			—			414,981
Property catastrophe	—			129,361			—			129,361
Property	135,089			132,501			—			267,590
Marine, energy, aviation and satellite	—			24,588			—			24,588
Specialty	181,131			—			—			181,131
Other (1)	54,073			15,983			—			70,056
Total P&C Operations	$	1,058,542		$	429,955		$	—		$	1,488,497
Corporate and Other:
Run-off Life operations - Annuity	$	—		$	—		$	30,087		$	30,087
Run-off Life operations - Other Life	—			—			43,809			43,809
Total Corporate and Other	$	—		$	—		$	73,896		$	73,896
Total	$	1,058,542		$	429,955		$	73,896		$	1,562,393
____________
-1	Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain other discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines.
The following tables summarize the Company’s net premiums earned by line of business for the six months ended June 30, 2014:
Six Months Ended June 30, 2014	Insurance			Reinsurance			Corporate			Total
(U.S. dollars in thousands)							and Other
P&C Operations:
Professional	$	542,936		$	94,343		$	—		$	637,279
Casualty	702,994			159,650			—			862,644
Property catastrophe	—			220,999			—			220,999
Property	282,607			277,576			—			560,183
Marine, energy, aviation and satellite	—			44,579			—			44,579
Specialty	356,857			—			—			356,857
Other (1)	111,036			57,027			—			168,063
Total P&C Operations	$	1,996,430		$	854,174		$	—		$	2,850,604
Corporate and Other:
Run-off Life operations - Annuity	$	—		$	—		$	53,362		$	53,362
Run-off Life operations - Other Life	—			—			81,467			81,467
Total Corporate and Other	$	—		$	—		$	134,829		$	134,829
Total	$	1,996,430		$	854,174		$	134,829		$	2,985,433
Six Months Ended June 30, 2013	Insurance			Reinsurance			Corporate			Total
(U.S. dollars in thousands)							and Other
P&C Operations:
Professional	$	700,650		$	96,414		$	—		$	797,064
Casualty	665,855			153,525			—			819,380
Property catastrophe	—			243,003			—			243,003
Property	259,539			273,770			—			533,309
Marine, energy, aviation and satellite	—			52,428			—			52,428
Specialty	364,096			—			—			364,096
Other (1)	107,494			35,969			—			143,463
Total P&C Operations	$	2,097,634		$	855,109		$	—		$	2,952,743
Corporate and Other:
Run-off Life operations - Annuity	$	—		$	—		$	59,771		$	59,771
Run-off Life operations - Other Life	—			—			79,570			79,570
Total Corporate and Other	$	—		$	—		$	139,341		$	139,341
Total	$	2,097,634		$	855,109		$	139,341		$	3,092,084
____________
-1	Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain other discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines.

Investments

Investments	6 Months Ended
	Jun. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Investments	'
	Investments
	(a) Fixed Maturities, Short-Term Investments and Equity Securities
	Classification of Fixed Income Securities
	During the three months ended June 30, 2014 fixed maturities with a carrying value of $2.8 billion were reclassified from held to maturity to available for sale in conjunction with the sale of XLLR as discussed in Note 3, “Sale of Life Reinsurance Subsidiary.” 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" 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. 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 GreyCastle. 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 other-than-temporary impairments (“OTTI”) recorded in accumulated other comprehensive income (“AOCI”) of the Company’s AFS investments, the Life Funds Withheld Assets designated as AFS, and HTM investments at June 30, 2014 and December 31, 2013, were as follows:
	30-Jun-14	Cost or			Gross			Gross Unrealized Losses			Fair Value			Non-credit Related OTTI (1)
	(U.S. dollars in thousands)	Amortized			Unrealized
		Cost			Gains
	Fixed maturities - AFS - Excluding Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported (2)	$	2,033,152		$	60,408		$	(9,266	)	$	2,084,294		$	—
	Corporate (3) (4)	9,345,654			425,093			(43,123		)	9,727,624			(4,758		)
	RMBS – Agency	3,218,551			104,874			(20,379		)	3,303,046			—
	RMBS – Non-Agency	395,629			41,054			(21,180		)	415,503			(70,645		)
	CMBS	1,098,149			33,562			(7,424		)	1,124,287			(2,561		)
	CDO	763,146			3,656			(28,729		)	738,073			(1,812		)
	Other asset-backed securities (5)	1,271,201			42,158			(3,087		)	1,310,272			(2,058		)
	U.S. States and political subdivisions of the States	1,836,889			109,258			(6,557		)	1,939,590			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported (2)	4,264,089			117,877			(26,105		)	4,355,861			—
	Total fixed maturities - AFS - Excluding Life Funds Withheld Assets	$	24,226,460		$	937,940		$	(165,850	)	$	24,998,550		$	(81,834	)
	Total short-term investments (2)	$	347,473		$	972		$	(771	)	$	347,674		$	—
	Total equity securities (6)	$	839,716		$	151,618		$	(2,624	)	$	988,710		$	—
	Total investments - AFS - Excluding Life Funds Withheld Assets	$	25,413,649		$	1,090,530		$	(169,245	)	$	26,334,934		$	(81,834	)
	Fixed maturities - AFS - Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported	$	16,356		$	1,869		$	—		$	18,225		$	—
	Corporate	2,722,907			294,539			—			3,017,446			—
	RMBS – Agency	3,990			33			—			4,023			—
	RMBS – Non-Agency	78,804			9,300			—			88,104			—
	CMBS	198,576			18,268			—			216,844			—
	CDO	—			—			—			—			—
	Other asset-backed securities	271,691			21,926			—			293,617			—
	U.S. States and political subdivisions of the States	—			—			—			—			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	1,546,747			259,365			—			1,806,112			—
	Total fixed maturities - AFS - Life Funds Withheld Assets	$	4,839,071		$	605,300		$	—		$	5,444,371		$	—
	Total investments - AFS	$	30,252,720		$	1,695,830		$	(169,245	)	$	31,779,305		$	(81,834	)
	Total fixed maturities - HTM	$	—		$	—		$	—		$	—		$	—
	___________
	-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	U.S. Government and Government-Related/Supported, Non-U.S. Sovereign Government, Provincials, Supranationals and Government-Related/Supported and Total short-term investments includes government-related securities with an amortized cost of $1,679.1 million and fair value of $1,721.8 million and U.S. Agencies with an amortized cost of $230.2 million and fair value of $256.8 million.
	-3	Included within Corporate 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 $155.9 million and an amortized cost of $143.6 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 values of these notes.
	-4	Included within Corporate are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions. These securities have a fair value of $28.1 million and an amortized cost of $32.6 million.
	-5	Covered Bonds with an amortized cost of $737.0 million and a fair value of $763.6 million are included within Other asset-backed securities to align the Company's classification to market indices.
	-6	Included within Total equity securities are investments in fixed income funds with a fair value of $92.1 million and an amortized cost of $92.1 million.
	31-Dec-13	Cost or			Gross			Gross Unrealized Losses			Fair Value			Non-credit Related OTTI (1)
	(U.S. dollars in thousands)	Amortized			Unrealized
		Cost			Gains
	Fixed maturities - AFS
	U.S. Government and Government-Related/Supported (2)	$	2,484,193		$	51,701		$	(34,043	)	$	2,501,851		$	—
	Corporate (3) (4)	10,802,332			433,097			(109,599		)	11,125,830			(4,758		)
	RMBS – Agency	3,540,101			68,098			(62,077		)	3,546,122			—
	RMBS – Non-Agency	396,798			33,096			(31,126		)	398,768			(74,528		)
	CMBS	1,223,313			39,255			(15,773		)	1,246,795			(2,753		)
	CDO	754,414			5,833			(42,934		)	717,313			(2,036		)
	Other asset-backed securities (5)	1,210,384			40,560			(8,840		)	1,242,104			(2,807		)
	U.S. States and political subdivisions of the States	1,821,499			55,083			(30,770		)	1,845,812			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported (2)	4,878,840			80,961			(84,260		)	4,875,541			—
	Total fixed maturities - AFS	$	27,111,874		$	807,684		$	(419,422	)	$	27,500,136		$	(86,882	)
	Total short-term investments (2)	$	455,470		$	962		$	(144	)	$	456,288		$	—
	Total equity securities (6)	$	903,201		$	154,506		$	(17,470	)	$	1,040,237		$	—
	Total investments - AFS	$	28,470,545		$	963,152		$	(437,036	)	$	28,996,661		$	(86,882	)
	Fixed maturities - HTM
	U.S. Government and Government-Related/Supported (2)	$	10,993		$	629		$	—		$	11,622		$	—
Corporate	1,386,863			113,179			(968		)	1,499,074			—
RMBS – Non-Agency	66,987			4,985			—			71,972			—
CMBS	144,924			11,864			—			156,788			—
Other asset-backed securities (5)	106,540			6,908			—			113,448			—
Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported (2)	1,142,388			136,585			(642		)	1,278,331			—
Total fixed maturities - HTM	$	2,858,695		$	274,150		$	(1,610	)	$	3,131,235		$	—
____________
-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	U.S. Government and Government-Related/Supported, Non-U.S. Sovereign Government, Provincials, Supranationals and Government-Related/Supported and Total short-term investments includes government-related securities with an amortized cost of $2,241.5 million and fair value of $2,275.6 million and U.S. Agencies with an amortized cost of $267.0 million and fair value of $284.3 million.
-3	Included within Corporate 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 $154.6 million and an amortized cost of $147.7 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 values of these notes.
-4	Included within Corporate are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions. These securities have a fair value of $282.2 million and an amortized cost of $286.2 million.
-5	Covered Bonds within Fixed maturities - AFS with an amortized cost of $526.4 million and a fair value of $553.1 million and Covered Bonds within Fixed maturities - HTM with an amortized cost of $8.6 million and a fair value of $8.7 million are included within Other asset-backed securities to align the Company's classification to market indices.
-6	Included within Total equity securities are investments in fixed income funds with a fair value of $87.4 million and an amortized cost of $100.0 million.
At June 30, 2014 and December 31, 2013, approximately 2.8% and 2.6%, 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 22.0% and 12.4% of the gross unrealized losses in the Company's fixed income securities portfolio, excluding Life Funds Withheld Assets, at June 30, 2014 and December 31, 2013, respectively, related to securities that were below investment grade or not rated. There were no unrealized losses within the Life Funds Withheld Assets at June 30, 2014.
Contractual Maturities Summary
The contractual maturities of AFS and HTM fixed income securities at June 30, 2014 and December 31, 2013 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.
	June 30, 2014 (1)						December 31, 2013 (1)
(U.S. dollars in thousands)	Amortized			Fair			Amortized			Fair
	Cost			Value			Cost			Value
Fixed maturities - AFS - Excluding Life Funds Withheld Assets
Due less than one year	$	2,069,219		$	2,088,394		$	2,052,251		$	2,060,365
Due after 1 through 5 years	9,384,790			9,657,635			10,075,087			10,305,986
Due after 5 through 10 years	4,518,798			4,693,075			5,474,120			5,507,450
Due after 10 years	1,506,977			1,668,265			2,385,406			2,475,233
	$	17,479,784		$	18,107,369		$	19,986,864		$	20,349,034
RMBS – Agency	3,218,551			3,303,046			3,540,101			3,546,122
RMBS – Non-Agency	395,629			415,503			396,798			398,768
CMBS	1,098,149			1,124,287			1,223,313			1,246,795
CDO	763,146			738,073			754,414			717,313
Other asset-backed securities	1,271,201			1,310,272			1,210,384			1,242,104
Total mortgage and asset-backed securities	$	6,746,676		$	6,891,181		$	7,125,010		$	7,151,102
Total fixed maturities - AFS - Excluding Life Funds Withheld Assets	$	24,226,460		$	24,998,550		$	27,111,874		$	27,500,136
Fixed maturities - AFS - Life Funds Withheld Assets
Due less than one year	$	138,250		$	144,169		$	—		$	—
Due after 1 through 5 years	680,192			725,237			—			—
Due after 5 through 10 years	1,159,277			1,297,027			—			—
Due after 10 years	2,308,291			2,675,350			—			—
	$	4,286,010		$	4,841,783		$	—		$	—
RMBS – Agency	3,990			4,023			—			—
RMBS – Non-Agency	78,804			88,104			—			—
CMBS	198,576			216,844			—			—
CDO	—			—			—			—
Other asset-backed securities	271,691			293,617			—			—
Total mortgage and asset-backed securities	$	553,061		$	602,588		$	—		$	—
Total fixed maturities - AFS - Life Funds Withheld Assets	$	4,839,071		$	5,444,371		$	—		$	—
Total fixed maturities - AFS	$	29,065,531		$	30,442,921		$	27,111,874		$	27,500,136
Fixed maturities - HTM
Due less than one year	$	—		$	—		$	65,651		$	66,766
Due after 1 through 5 years	—			—			240,802			255,322
Due after 5 through 10 years	—			—			455,633			492,095
Due after 10 years	—			—			1,778,158			1,974,844
	$	—		$	—		$	2,540,244		$	2,789,027
RMBS – Non-Agency	—			—			66,987			71,972
CMBS	—			—			144,924			156,788
Other asset-backed securities	—			—			106,540			113,448
Total mortgage and asset-backed securities	$	—		$	—		$	318,451		$	342,208
Total fixed maturities - HTM	$	—		$	—		$	2,858,695		$	3,131,235
____________
-1	Included in the table above within Fixed Maturities - AFS - Excluding Life Funds Withheld Assets, are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions, at their fair values of $28.1 million and $282.2 million at June 30, 2014 and December 31, 2013, respectively. These securities are reflected in the table based on their call date and have net unrealized losses of $4.5 million and $4.0 million at June 30, 2014 and December 31, 2013, respectively.
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, certain deposit liabilities and annuity contracts require the use of pledged assets. At June 30, 2014 and December 31, 2013, the Company had $16.1 billion and $15.5 billion in pledged assets, respectively.
(b) Gross Unrealized Losses
The following is an analysis of how long the AFS and HTM securities at June 30, 2014 and December 31, 2013 had been in a continual unrealized loss position:
	Less than 12 months						Equal to or greater
							than 12 months
30-Jun-14	Fair			Gross			Fair			Gross
(U.S. dollars in thousands)	Value			Unrealized			Value			Unrealized
				Losses						Losses
Fixed maturities and short-term investments - AFS - Excluding Life Funds Withheld Assets
U.S. Government and Government-Related/Supported	$	155,192		$	(1,345	)	$	455,830		$	(7,926	)
Corporate	510,313			(4,910		)	820,499			(38,302		)
RMBS – Agency	28,954			(123		)	652,745			(20,256		)
RMBS – Non-Agency	26,501			(374		)	216,406			(20,806		)
CMBS	65,205			(197		)	202,685			(7,227		)
CDO	69,479			(268		)	492,272			(28,461		)
Other asset-backed securities	60,338			(130		)	79,464			(2,957		)
U.S. States and political subdivisions of the States	32,636			(260		)	222,479			(6,297		)
Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	548,628			(6,517		)	515,159			(20,265		)
Total fixed maturities and short-term investments - AFS - Excluding Life Funds Withheld Assets	$	1,497,246		$	(14,124	)	$	3,657,539		$	(152,497	)
Total fixed maturities and short-term investments - AFS - Life Funds Withheld Assets	$	—		$	—		$	—		$	—
Total fixed maturities and short-term investments - AFS	$	1,497,246		$	(14,124	)	$	3,657,539		$	(152,497	)
Total equity securities	$	46,158		$	(2,624	)	$	—		$	—
Total fixed maturities - HTM	$	—		$	—		$	—		$	—
	Less than 12 months						Equal to or greater
							than 12 months
31-Dec-13	Fair			Gross			Fair			Gross
(U.S. dollars in thousands)	Value			Unrealized			Value			Unrealized
				Losses						Losses
Fixed maturities and short-term investments - AFS
U.S. Government and Government-Related/Supported	$	1,333,704		$	(30,474	)	$	44,158		$	(3,614	)
Corporate	2,756,235			(59,497		)	513,106			(50,160		)
RMBS – Agency	1,485,261			(50,362		)	169,704			(11,715		)
RMBS – Non-Agency	14,204			(604		)	240,946			(30,522		)
CMBS	432,820			(6,816		)	107,192			(8,957		)
CDO	58,239			(217		)	574,613			(42,717		)
Other asset-backed securities	196,639			(2,149		)	96,528			(6,691		)
U.S. States and political subdivisions of the States	463,974			(23,124		)	64,324			(7,646		)
Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	2,130,792			(56,866		)	306,873			(27,435		)
Total fixed maturities and short-term investments - AFS	$	8,871,868		$	(230,109	)	$	2,117,444		$	(189,457	)
Total equity securities	$	155,453		$	(17,470	)	$	—		$	—
Fixed maturities - HTM
Corporate	$	46,034		$	(941	)	$	642		$	(27	)
Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	—			—			11,894			(642		)
Total fixed maturities - HTM	$	46,034		$	(941	)	$	12,536		$	(669	)
The Company had gross unrealized losses totaling $169.2 million on 1,385 securities out of a total of 7,668 held at June 30, 2014 in its AFS - Excluding Life Funds Withheld Assets portfolio, which 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. At June 30, 2014, the AFS - Excluding Life Funds Withheld Assets portfolio included structured credit securities with gross unrealized losses of $10.6 million, which had a fair value of $4.6 million, and a cumulative fair value decline of greater than 50% of amortized cost. All of these securities are mortgage and asset-backed securities. These greater than 50% impaired securities include gross unrealized losses of $10.4 million on CDOs and $0.2 million on non-Agency RMBS.
(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 June 30,						Six months ended June 30,
(U.S. dollars in thousands)	2014			2013			2014			2013
Net realized gains (losses) on investments - excluding Life Funds Withheld Assets:
Gross realized gains	$	118,947		$	64,865		$	170,160		$	138,038
Gross realized losses on investments sold	(13,487		)	(21,508		)	(41,744		)	(53,534		)
OTTI on investments, net of amounts transferred to other comprehensive income	(24,616		)	(2,389		)	(28,343		)	(7,027		)
	$	80,844		$	40,968		$	100,073		$	77,477
Net realized gains (losses) on investments - Life Funds Withheld Assets:
Gross realized gains	$	624		$	—		$	624		$	—
Gross realized losses on investments sold	—			—			—			—
OTTI on investments, net of amounts transferred to other comprehensive income	(8,771		)	—			(8,771		)	—
	$	(8,147	)	$	—		$	(8,147	)	$	—
Total net realized gains (losses) on investments	$	72,697		$	40,968		$	91,926		$	77,477
The main components of the net impairment charges of $24.6 million for investments excluding Life Funds Withheld Assets for the three months ended June 30, 2014 were:
▪	$10.3 million related to certain equities as the holdings were in a loss position for more than 11 months.
▪	$12.5 million related to Other Investments.
The following table sets forth the amount of credit loss impairments on fixed income securities held by the Company as of the dates or the periods indicated, for which a portion of the OTTI loss was recognized in OCI, and the corresponding changes in such amounts.
Credit Loss Impairments	Three months ended June 30,						Six months ended June 30,
(U.S. dollars in thousands)	2014			2013			2014			2013
Opening balance at beginning of indicated period	$	171,382		$	260,066		$	174,805		$	268,707
Credit loss impairment recognized in the current period on securities not previously impaired	30			27			41			527
Credit loss impairments previously recognized on securities which matured, paid down, prepaid or were sold during the period	(3,322		)	(55,144		)	(7,571		)	(61,619		)
Credit loss impairments previously recognized on securities impaired to fair value during the period	—			—			—			—
Additional credit loss impairments recognized in the current period on securities previously impaired	892			1,996			3,153			4,300
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	(3,105		)	(4,083		)	(4,551		)	(9,053		)
Balance at June 30,	$	165,877		$	202,862		$	165,877		$	202,862
During the three months ended June 30, 2014 and 2013, the $3.3 million and $55.1 million, respectively, of credit loss impairments previously recognized on securities that matured, or were paid down, prepaid or sold, includes $2.5 million and $54.4 million, respectively, of non-Agency RMBS.
During the six months ended June 30, 2014 and 2013, the $7.6 million and $61.6 million, respectively, of credit loss impairments previously recognized on securities that matured, or were paid down, prepaid or sold, includes $5.2 million and $60.2 million, respectively, of non-Agency RMBS.

Derivative_Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments	'
	Derivative Instruments
	The Company enters into derivative instruments for both risk management and investment purposes. 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 in 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, 2013.
	The following table summarizes information on the location and gross amounts of derivative fair values contained in the consolidated balance sheets at June 30, 2014 and December 31, 2013:
		June 30, 2014													December 31, 2013
	(U.S. dollars in thousands)	Asset				Asset			Liability			Liability			Asset		Asset		Liability		Liability
		Derivative				Derivative			Derivative			Derivative			Derivative		Derivative		Derivative		Derivative
		Notional				Fair Value			Notional			Fair Value			Notional		Fair Value		Notional		Fair Value
		Amount				-1			Amount			-1			Amount		-1		Amount		-1
	Derivatives designated as hedging instruments:
	Foreign exchange contracts	$	891,217			$	45,597		$	1,315,385		$	35,265		$	1,005,610	$	26,098	$	2,572,227	$	70,462
	Derivatives not designated as hedging instruments:
	Investment Related Derivatives:
	Interest rate exposure	$	1,295,267			$	259		$	28,090		$	—		$	30,702	$	266	$	10,259	$	8
	Foreign exchange exposure	190,870				1,914			105,797			3,004			17,497		12		50,614		680
	Credit exposure	4,566				3			14,270			9,988			—		—		340,020		15,128
	Financial market exposure	46,645				344			43,468			—			58,232		1,111		14,821		77
	Financial Operations Derivatives: (2)
	Credit exposure	—				—			41,346			8,930			—		—		44,234		4,190
	Other Non-Investment Derivatives:
	Guaranteed minimum income benefit contract	50,802				12,453			50,802			12,453			—		—		53,564		14,940
	Modified coinsurance funds withheld contracts (3)	65,721				—			5,659,644			—			66,369		—		—		—
	Total derivatives not designated as hedging instruments	$	1,653,871			$	14,973		$	5,943,417		$	34,375		$	172,800	$	1,389	$	513,512	$	35,023
	____________
	-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 intentions to settle the contracts on a net basis.
	-2	Financial operations derivatives represent interests in variable interest entities as described in Note 12, “Variable Interest Entities".
	-3	The fair value movements in derivative assets and liabilities relating to modified coinsurance funds withheld contracts are included within the 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 at June 30, 2014 is the current period net realized and unrealized loss on life retrocession embedded derivative of $17.5 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 paid relating to derivative liabilities contained in the consolidated balance sheets at June 30, 2014 and December 31, 2013:
												Gross Amounts Not Offset in the Balance Sheets
	30-Jun-14	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
	(U.S. dollars in thousands)
	Derivative Assets	$	60,570			$	1,240		$	59,330		$	—		$	3,160	$	56,170
	Derivative Liabilities	$	69,640			$	1,240		$	68,400		$	—		$	—	$	68,400
	31-Dec-13
	(U.S. dollars in thousands)
	Derivative Assets	$	27,487			$	1,342		$	26,145		$	—		$	—	$	26,145
	Derivative Liabilities	$	105,485			$	1,342		$	104,143		$	—		$	19,847	$	84,296
	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. At June 30, 2014 the Company held cash collateral related to foreign currency derivative positions and certain other derivative positions of $3.2 million and at December 31, 2013, the Company paid cash collateral related to foreign currency derivative positions and certain other derivative positions of $19.8 million. The assets related to the net collateral paid were recorded as Other assets 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 derivative 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 hedge portions of its liabilities against changes in the applicable designated benchmark interest rate. Interest rate swaps may also be used to hedge the changes in fair value of certain fixed rate liabilities and fixed income securities due to changes in the designated benchmark interest rate. In addition, the Company utilizes foreign exchange contracts to hedge the fair value of certain fixed income securities as well as to hedge certain net investments in foreign operations.
	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 three and six months ended June 30, 2014 and 2013:
					Hedged Items - Amount of Gain/(Loss) Recognized in Income Attributable to Risk
	Derivatives Designated as Fair Value Hedges:	Gain/(Loss)				Fixed Maturity			Ineffective
	Three Months Ended June 30, 2014	Recognized				Investments			Portion of
	(U.S. dollars in thousands)	in Income on							Hedging
		Derivative							Relationship -
									Gain/(Loss)
	Interest rate exposure	$	—
	Foreign exchange exposure	(9,132		)
	Total	$	(9,132	)		$	7,082		$	(2,050	)
	Three Months Ended June 30, 2013
	(U.S. dollars in thousands)
	Interest rate exposure	$	—
	Foreign exchange exposure	(5,002		)
	Total	$	(5,002	)		$	4,496		$	(506	)
	Six Months Ended June 30, 2014
	(U.S. dollars in thousands)
	Interest rate exposure	$	—
	Foreign exchange exposure	(15,663		)
	Total	$	(15,663	)		$	15,407		$	(256	)
	Six Months Ended June 30, 2013
	(U.S. dollars in thousands)
	Interest rate exposure	$	—
Foreign exchange exposure	25,243
Total	$	25,243			$	(24,274	)	$	969
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. In addition, the periodic coupon settlements relating to the interest rate swaps are recorded as adjustments to net investment income for the hedges of fixed maturity investments.
Settlement of Fair Value Hedges
A summary of the fair value hedges that have been settled and their impact on results during the three and six months ended June 30, 2014 and 2013, as well as the remaining balance of fair value hedges and average years remaining to maturity are shown below:
Settlement of Fair Value Hedges - Summary	Fair Value Hedges - Notes							Fair Value Hedges - Deposit
	Payable and Debt							Liabilities
	June 30,							June 30,
(U.S. dollars in thousands, except years)	2014				2013			2014			2013
Cumulative reduction to interest expense	$	20,810			$	16,903		$	90,615		$	29,257
Remaining balance	$	814			$	4,721		$	142,580		$	203,938
Weighted average years remaining to maturity	0.2				1.2			24			24.2
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 as noted above. 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 six months ended June 30, 2014 and 2013, 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 six months ended June 30, 2014 and 2013:
Derivative Instruments Designated as Hedges of the	Three months ended June 30,							Six months ended June 30,
Net Investment in a Foreign Operation - Summary
(U.S. dollars in thousands)	2014				2013			2014			2013
Weighted average of U.S. dollar equivalent of foreign denominated net assets	$	2,270,090			$	2,588,385		$	2,478,772		$	2,556,103
Derivative gains (losses)	$	(2,170	)		$	(6,135	)	$	(1,210	)	$	54,479
(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 six months ended June 30, 2014 and 2013:
Net Realized and Unrealized Gains (Losses) on Derivative Instruments	Three months ended June 30,							Six months ended June 30,
(U.S. dollars in thousands)	2014				2013			2014			2013
Investment Related Derivatives:
Interest rate exposure	$	8,978			$	288		$	9,326		$	489
Foreign exchange exposure	(1,490		)		(2,690		)	1,798			(4,288		)
Credit exposure	411				(1,178		)	7			(1,994		)
Financial market exposure	2,508				(2,736		)	3,378			2,616
Financial Operations Derivatives:
Credit exposure	447				1,087			(4,353		)	1,329
Other Non-Investment Derivatives:
Guaranteed minimum income benefit contract	633				2,306			2,257			6,002
Modified coinsurance funds withheld contract	2,162				(1,676		)	1,252			(2,343		)
Total gain (loss) recognized in income from derivatives not designated as hedging instruments	$	13,649			$	(4,599	)	$	13,665		$	1,811
Amount of gain (loss) recognized in income from ineffective	(2,050		)		(506		)	(256		)	969
portion of fair value hedges
Net realized and unrealized gains (losses) on derivative instruments	$	11,599			$	(5,105	)	$	13,409		$	2,780
Net realized and unrealized gains (losses) on life retrocession embedded derivative	$	(17,546	)		$	—		$	(17,546	)	$	—
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, 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 investment purposes. 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 use them 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 and basket credit default swaps, 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 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
At June 30, 2014 and December 31, 2013, the Company held one 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. This is a European project finance loan participation that benefits from a deficiency guarantee from the German state and federal governments, in the current amount of 68% of the outstanding exposure at June 30, 2014, following the scheduled expiry of a portion of this guarantee. An aggregate summary of the credit derivative exposure at June 30, 2014 and December 31, 2013 is as follows:
Financial Operations Derivatives - Credit Exposure Summary:	30-Jun-14				31-Dec-13
(U.S. dollars in thousands)
Principal outstanding	$	39,748			$	42,080
Interest outstanding	1,598				2,154
Aggregate outstanding exposure	$	41,346			$	44,234
Total liability recorded	$	8,930			$	4,190
Weighted average contractual term to maturity	3.3 years				3.7 years
Underlying obligations credit rating	CC				CC
At June 30, 2014 and December 31, 2013, there was no reported event of default on this obligation. However, the liability shown in the above table has been recorded due to the combination of the reduction in the deficiency guarantee percentage and a deterioration of the credit quality of the underlying obligations. Credit derivatives are recorded at fair value based upon prices received from the investment bank counterparty, or by using models developed by the Company. Although the Company does not have access to the specific unobservable inputs that may be used in the determination of fair value, it expects that the significant inputs considered would include changes in interest rates, future default rates, credit spreads, changes in credit quality, future expected recovery rates and other market factors. The change resulting from movements in credit and credit quality spreads is unrealized as the credit derivative is not traded to realize this resultant value.
(d)(iii) Other Non-Investment Derivatives
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. In addition, 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.
In addition, the Company has entered into Life Retro Arrangements as described in Notes 2, "Significant Accounting Policies - (a) Investments Related to Life Retrocession Agreements written on a Funds Withheld Basis" and " - (b) Reinsurance" and Note 3, "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.
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:	May 30 to June 30
(U.S. dollars in thousands)	2014
Interest income	$	(19,944	)
Realized and unrealized gains (losses) on Life Funds Withheld Assets	1,893
Other	505
Net realized and unrealized gains (losses) on life retrocession embedded derivative	$	(17,546	)
(e) Contingent Credit Features
Certain derivative agreements entered into by the Company or its subsidiaries contain rating downgrade provisions that permit early termination of the agreement 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 early terminate such agreements due to a 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 June 30, 2014 and December 31, 2013 were as follows:
Contingent Credit Features - Summary:	30-Jun-14				31-Dec-13
(U.S. dollars in thousands)
Aggregate fair value of derivative agreements with downgrade provisions in a net liability position	$	6,728			$	47,703
Collateral posted to counterparty	$	—			$	13,260

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and other Intangible Assets	'
	Goodwill and Other Intangible Assets
	During the first quarter of 2014, goodwill and intangible assets increased as a result of the completion of an acquisition and the impact of foreign currency translation. The transaction was accounted for using the acquisition method under which the Company recorded the identifiable assets and liabilities at their acquisition date fair values, and recorded the excess of consideration transferred over the net assets acquired as goodwill and intangible assets. The fair value of identifiable assets and liabilities acquired, as well as amounts recorded in the Company’s consolidated results since the acquisition date, are not material. The Company’s goodwill and intangible assets of $455.1 million at June 30, 2014 related to the Reinsurance segment.

Share_Capital

Share Capital	6 Months Ended
	Jun. 30, 2014
Stockholders' Equity Note [Abstract]	'
Share Capital	'
	Share Capital
	(a) Authorized and Issued
	Buybacks of Ordinary Shares
	On February 22, 2013, XL-Ireland announced that its Board of Directors approved a new share buyback program, authorizing the purchase of up to $850 million of its ordinary shares (the “Share Buyback Program”). At December 31, 2013, $275 million remained available for purchase under the Share Buyback Program. On February 21, 2014, XL-Ireland announced that its Board of Directors approved an increase to the Share Buyback Program, authorizing the purchase of up to $1.0 billion of our ordinary shares. This authorization includes the approximately $200.0 million that remained under the Share Buyback Program prior to the increase. During the three and six months ended June 30, 2014, the Company purchased and canceled 5.5 million and 11.3 million ordinary shares under the Share Buyback Program for $175.0 million and $350.0 million, respectively. At June 30, 2014, $717.6 million remained available for purchase under the Share Buyback Program.
	All share buybacks were carried out by way of redemption in accordance with Irish law and the Company's constitutional documents. All shares so redeemed were canceled upon redemption.
	(b) Stock Plans
	The Company's performance incentive programs provide for grants of stock options, restricted stock, 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 18, “Share Capital,” to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013 for further information on the Company's performance incentive programs and associated accounting.
	During the six months ended June 30, 2014, the Company granted approximately 1.0 million stock options with a weighted-average grant date fair value of $8.60 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	1.99	%
	Risk free interest rate	1.8	%
	Volatility	33.8	%
	Expected lives	6.0 years
	During the six months ended June 30, 2014, the Company granted 42,444 restricted stock awards to certain employees and directors of the Company and its subsidiaries with an aggregate grant date fair value of approximately $1.4 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 six months ended June 30, 2014, the Company granted approximately 1.8 million restricted stock units to certain employees of the Company and its subsidiaries with an aggregate grant date fair value of approximately $54.3 million. Each 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 anniversary of the date of grant. 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 six months ended June 30, 2014, the Company granted approximately 0.6 million performance units (representing a potential maximum share payout of approximately 1.1 million ordinary shares) to certain employees with an aggregate grant date fair value of approximately $16.3 million. The performance units vest after three years, subject to the achievement of stated performance metrics, and entitle the holder to ordinary shares of the Company. There are no dividend rights associated with the performance units. 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 a combination of corporate and business segment performance along with each employee's continued service through the vesting date. Performance targets are based on relative and absolute financial performance metrics.

Notes_Payable_and_Debt_and_Fin

Notes Payable and Debt and Financing Arrangements	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Notes Payable and Debt and Financing Arrangements	'
	Notes Payable and Debt and Financing Arrangements
	(a) Notes Payable and Debt
	All outstanding debt of the Company at June 30, 2014 and December 31, 2013 was issued by XLIT Ltd. (“XL-Cayman”), a 100% owned subsidiary of XL-Ireland and the only direct subsidiary thereof. 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 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 23, “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, 2013.
	The Company was in compliance with all covenants by significant margins at June 30, 2014, and the Company currently remains in compliance with all covenants.
	(b) Letter of Credit Facilities and Other Sources of Collateral
	The Company has several 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 at June 30, 2014 and December 31, 2013 were as follows:
	Letter of Credit Summary:	June 30, 2014 (1)			December 31, 2013 (1)
	(U.S. dollars in thousands except percentages)
	Revolving credit facility (2)	$	1,000,000		$	1,000,000
	Available letter of credit facilities - commitments (3)	$	3,575,000		$	3,575,000
	Available letter of credit facilities - in use	$	1,870,818		$	1,895,425
	Collateralized by certain assets of the Company’s investment portfolio	67.2		%	67.6		%
	____________
	-1	At June 30, 2014 and December 31, 2013, there were seven available letter of credit facilities.
	-2	At June 30, 2014 and December 31, 2013,the revolving credit available under the November 2013 unsecured credit agreement, which provides for issuance of letters of credit and revolving credit loans up to $1 billion, was unutilized. The credit agreements entered into with Citicorp USA, Inc. in May through November 2013 (the "Citi Agreements") provide for issuance of letters of credit and revolving credit loans up to an aggregate amount of $575.0 million. At June 30, 2014, $575.0 million of letters of credit were issued under these agreements and therefore such amount is not included in the table.
	-3	The Company has the option to increase the size of the facilities under the Syndicated Credit Agreements by an additional $500 million across such facilities. The Company also has the option to increase the maximum amount of the letters of credit and revolving credit loans available under the 2013 Citi Agreements with the lender's and issuing lender's consent.
	For details regarding these facilities see Item 8, Note 13(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, 2013.

Related_Party_Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2014
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	Related Party Transactions
	At each of June 30, 2014 and 2013, the Company owned minority stakes in five 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 6, “Investments in Affiliates,” to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2013.
	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 six months ended June 30, 2014 and 2013, these contracts resulted in reported net premiums written, net reported claims and reported acquisition costs as summarized below.
	(U.S. dollars in thousands)	Three months ended June 30,				Six months ended June 30,
		2014		2013		2014		2013
	Reported net premiums written	$	18,025	$	11,415	$	36,191	$	24,155
	Net losses and loss expenses incurred	$	7,692	$	6,117	$	14,301	$	11,766
	Reported acquisition costs	$	6,994	$	5,355	$	15,553	$	10,707
	Several of the Company’s wholly-owned subsidiaries retrocede assumed reinsurance business to special purpose reinsurers that receive capital from funds managed by New Ocean Capital Management Limited (“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 six months ended June 30, 2014, 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.

Variable_Interest_Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2014
Variable Interest Entities Disclosure [Abstract]	'
Variable Interest Entities	'
	Variable Interest Entities
	At times, the Company has utilized variable interest entities (“VIEs”) both indirectly and directly in the ordinary course of the Company's business.
	The Company invests in CDOs and other investment vehicles that are issued through VIEs as part of the Company's investment portfolio. The activities of these VIEs are generally limited to holding the underlying collateral used to service investments therein. The Company's involvement in these entities is passive in nature and we are not the arranger of these entities. In addition, the Company has not been involved in establishing these entities and is not the primary beneficiary of these VIEs as contemplated in current authoritative accounting guidance.
	The Company has a limited number of remaining outstanding credit enhancement exposures, including written financial guarantee and credit default swap contracts. The obligations related to these transactions are often securitized through VIEs. The Company is not the primary beneficiary of these VIEs as contemplated in current authoritative accounting guidance on the basis that management does not believe that the Company has the power to direct the activities, such as asset selection and collateral management, which most significantly impact each entity's economic performance. For further details on the nature of the obligations and the size of the Company's maximum exposure, see Note 7, “Derivative Instruments,” and Note 14 (a), “Commitments and Contingencies - Financial Guarantee Exposures.”
	During the third quarter of 2013, the Company, along with other investors, formed New Ocean, a new Bermuda-based company, 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 was material to the Company during the three and six months ended June 30, 2014. 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 $0.2 million and $0.3 million at June 30, 2014 and December 31, 2013, 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 three months ended March 31, 2014, New Ocean FCFL invested in a special purpose 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. Most of Vector Re’s current underwriting activity relates to reinsurance business assumed from XL subsidiaries. Underwriting administration and claims services are provided to Vector Re by XL 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 Vector Re. Accordingly, included in the consolidated financial statements of the Company are New Ocean FCFL's and Vector Re's total net assets of $89.3 million and $46.5 million at June 30, 2014 and December 31, 2013, respectively. The Company’s share of revenue and net income in these VIEs was not material to the Company for three and six months ended June 30, 2014. All inter-company transactions between XL entities have been eliminated in consolidation. The equity interest attributable to third party investors in New Ocean FCFL and Vector Re recorded in the Company’s Consolidated Balance Sheets as "Non-controlling interest in equity of consolidated subsidiaries" was $29.6 million and $6.9 million at June 30, 2014 and December 31, 2013, respectively.

Computation_of_Earnings_Per_Or

Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent	6 Months Ended
	Jun. 30, 2014
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 share for the three and six months ended June 30, 2014 and 2013:
		Three Months Ended					Six Months Ended June 30,
		June 30,
	(U.S. dollars in thousands, except per share amounts)	2014			2013		2014			2013
	Basic earnings per ordinary share & ordinary share equivalents outstanding:
	Net income (loss) attributable to ordinary shareholders	$	(279,261	)	$	272,698	$	(23,544	)	$	623,488
	Weighted average ordinary shares outstanding, in thousands - basic	270,924			289,513		273,616			292,277
	Basic earnings per ordinary share & ordinary share equivalents outstanding	$	(1.03	)	$	0.94	$	(0.09	)	$	2.13
	Diluted earnings per ordinary share & ordinary share equivalents outstanding:
	Weighted average ordinary shares outstanding, in thousands - basic	270,924			289,513		273,616			292,277
	Impact of share-based compensation and certain conversion features, in thousands	—			4,820		—			4,767
	Weighted average ordinary shares outstanding, in thousands - diluted	270,924			294,333		273,616			297,044
	Diluted earnings per ordinary share & ordinary share equivalents outstanding	$	(1.03	)	$	0.93	$	(0.09	)	$	2.1
	Dividends per ordinary share	$	0.16		$	0.14	$	0.32		$	0.28
	For the three months ended June 30, 2014 and 2013, and for the six months ended June 30, 2014 and 2013, ordinary shares available for issuance under share-based compensation plans of 16.8 million and 6.0 million, and 16.6 million and 6.3 million, respectively, were not included in the calculation of diluted earnings per share because the assumed exercise or issuance of such shares would be anti-dilutive.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	(a) Financial Guarantee Exposures
	A summary of the Company's outstanding financial guarantee exposures at June 30, 2014 and December 31, 2013 is as follows:
	Financial Guarantee Exposure Summary	30-Jun-14		31-Dec-13
	(U.S. dollars in thousands except number of contracts and term to maturity)
	Opening number of financial guarantee contracts	3		4
	Number of financial guarantee contracts matured, prepaid or commuted during the period	—		(1		)
	Closing number of financial guarantee contracts	3		3
	Principal outstanding	$	108,255	$	108,255
	Interest outstanding	$	—	$	—
	Aggregate exposure outstanding	$	108,255	$	108,255
	Total gross claim liability recorded	$	—	$	—
	Total unearned premiums and fees recorded	$	61	$	134
	Weighted average contractual term to maturity in years	25.6		26
	The Company's outstanding financial guarantee contracts at June 30, 2014 provide credit support for a variety of collateral types with the exposures comprised of an aggregate $108.3 million notional financial guarantee on three notes backed by zero coupon long dated bonds and bank perpetual securities, including some issued by European financials.
	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. At June 30, 2014, 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 at June 30, 2014.
	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 at June 30, 2014, no such disclosures were considered necessary.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2014
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 six months ended June 30, 2014 and 2013 are as follows:
	Three months ended June 30, 2014	Unrealized Gains (Losses) on Investments (1)			OTTI Losses Recognized in AOCI			Foreign Currency Translation Adjustments			Underfunded Pension Liability			Cash Flow Hedge		Total
	(U.S. dollars in thousands)
	Balance, beginning of period, net of tax	$	1,032,941		$	(85,894	)	$	10,661		$	(13,270	)	$	2,223	$	946,661
	OCI before reclassifications	363,348			—			(3,621		)	(8		)	—		359,719
	Amounts reclassified from AOCI	(74,337		)	1,640			—			—			110		(72,587		)
	Tax benefit (expense)	(20,774		)	(4		)	(5,981		)	—			—		(26,759		)
	Net current period OCI - net of tax	268,237			1,636			(9,602		)	(8		)	110		260,373
	Balance, end of period, net of tax	$	1,301,178		$	(84,258	)	$	1,059		$	(13,278	)	$	2,333	$	1,207,034
	Three months ended June 30, 2013
	(U.S. dollars in thousands)
	Balance, beginning of period, net of tax	$	1,474,553		$	(116,189	)	$	65,480		$	(20,506	)	$	1,784	$	1,405,122
	OCI before reclassifications	(701,365		)	—			(25,524		)	(91		)	—		(726,980		)
	Amounts reclassified from AOCI	(55,408		)	14,440			—			—			110		(40,858		)
	Tax benefit (expense)	71,671			(2		)	1,806			—			—		73,475
	Net current period OCI - net of tax	(685,102		)	14,438			(23,718		)	(91		)	110		(694,363		)
	Balance, end of period, net of tax	$	789,451		$	(101,751	)	$	41,762		$	(20,597	)	$	1,894	$	710,759
	Six months ended June 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	628,599			—			(9,521		)	(39		)	—		619,039
	Amounts reclassified from AOCI	(96,975		)	5,049			—			—			220		(91,706		)
	Tax benefit (expense)	(52,878		)	(117		)	(3,961		)	—			—		(56,956		)
	Net current period OCI - net of tax	478,746			4,932			(13,482		)	(39		)	220		470,377
	Balance, end of period, net of tax	$	1,301,178		$	(84,258	)	$	1,059		$	(13,278	)	$	2,333	$	1,207,034
	Six months ended June 30, 2013
	(U.S. dollars in thousands)
	Balance, beginning of period, net of tax	$	1,591,210		$	(121,371	)	$	69,399		$	(20,892	)	$	1,674	$	1,520,020
	OCI before reclassifications	(789,054		)	—			(30,576		)	295			—		(819,335		)
	Amounts reclassified from AOCI	(97,102		)	19,625			—			—			220		(77,257		)
	Tax benefit (expense)	84,397			(5		)	2,939			—			—		87,331
	Net current period OCI - net of tax	(801,759		)	19,620			(27,637		)	295			220		(809,261		)
	Balance, end of period, net of tax	$	789,451		$	(101,751	)	$	41,762		$	(20,597	)	$	1,894	$	710,759
	____________
	-1	Included in these amounts are the impact of Shadow Adjustments. During the year ended December 31, 2013, the initial impact of $44.7 million was recorded. During the six months ended June 30, 2014, additional impacts of $474.5 million were recorded, resulting in a total cumulative impact of shadow adjustments on future policy benefit reserves of $519.2 million at June 30, 2014.
	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 six months ended June 30, 2014 and 2013 are as follows:
	Gross Amount Reclassified From AOCI
	Details About AOCI Components	Three months ended June 30, 2014			Three months ended June 30, 2013			Six months ended June 30, 2014			Six months ended June 30, 2013			Affected Line Item in the Statement of Income
	(U.S. dollars in thousands)
	Unrealized gains and losses on investments:
		$	(107,470	)	$	(56,969	)	$	(132,384	)	$	(102,391	)	Net realized gains (losses) on investments sold
		33,133			1,561			35,409			5,289			OTTI on investments
		$	(74,337	)	$	(55,408	)	$	(96,975	)	$	(97,102	)	Total before tax
		1,477			(3,560		)	1,930			(3,286		)	Provision (benefit) for income tax
		$	(72,860	)	$	(58,968	)	$	(95,045	)	$	(100,388	)	Net of tax
	OTTI losses recognized in OCI:
		$	1,386		$	13,612		$	3,344		$	17,887		Net realized gains (losses) on investments sold
		254			828			1,705			1,738			OTTI on investments transferred to (from) OCI
		$	1,640		$	14,440		$	5,049		$	19,625		Total before tax
		(4		)	(2		)	(117		)	(5		)	Provision (benefit) for income tax
		$	1,636		$	14,438		$	4,932		$	19,620		Net of tax
	Gains and losses on cash flow hedges:
	Interest rate contracts	$	110		$	110		$	220		$	220		Interest Expense
		—			—			—			—			Provision (benefit) for income tax
		$	110		$	110		$	220		$	220		Net of tax
	Total reclassifications for the period, gross of tax	$	(72,587	)	$	(40,858	)	$	(91,706	)	$	(77,257	)
	Tax benefit (expense)	1,473			(3,562		)	1,813			(3,291		)
	Total reclassifications for the period, net of tax	$	(71,114	)	$	(44,420	)	$	(89,893	)	$	(80,548	)

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Investments related to life retrocession agreements written on a Funds Withheld basis	'
	Investments Related to Life Retrocession Agreements written on a Funds Withheld Basis
	The designated investments that support certain life retrocession agreements written on a funds withheld basis ("Life Funds Withheld Assets") are included within "Total investments available for sale". Investment results for these assets - including interest income, unrealized gains and losses, and gains and losses from sales - are passed directly to the reinsurer pursuant to a contractual arrangement which is accounted for as a derivative. See Note 3, "Sale of Life Reinsurance Subsidiary", for information regarding the reinsurance arrangement.
	Changes in the fair value of the embedded derivative associated with these life retrocession agreements are recorded in “Net realized and unrealized gains (losses) on life retrocession embedded derivative” on the consolidated statements of income. The fair value of the embedded derivative is included within “Funds withheld on life retrocession arrangements, net of future policy benefit reserves recoverable” on the consolidated balance sheets.
Reinsurance	'
	Reinsurance
	The Company enters into reinsurance agreements with other companies in the normal course of business. All balances related to reinsurance agreements are reported on a gross basis on our consolidated balance sheets as an asset for amounts recoverable from reinsurers or as a component of other liabilities for amounts, such as premiums, owed to the reinsurers, with the exception of the life retrocession agreements written on a funds withheld basis. The future policy benefit reserves recoverable related to these retrocession agreements are netted against the funds withheld liability owing to the counterparty on the consolidated balance sheets due to the right of offset.
Recent accounting pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, the FASB issued an accounting standards update concerning the presentation of unrecognized tax benefits. The objective of the guidance is to improve the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The guidance seeks to reduce the diversity in practice by providing guidance on the presentation of unrecognized tax benefits to better reflect the manner in which an entity would settle, at the reporting date, any additional income taxes that would result from the disallowance of a tax position when net operating loss carryforwards, similar tax losses, or tax credit carryforwards exist. The guidance was effective for annual and interim reporting periods beginning after December 15, 2013, with both early adoption and retrospective application permitted. This guidance did not have a significant impact on the Company's financial condition, results of operations or cash flows.
	In April 2014, the FASB issued an accounting standards update intended to improve financial reporting by changing key criteria used to evaluate whether disposal transactions meet the definition of discontinued operations. Under the guidance only those disposals of components of an entity - either by sale or otherwise - which represent strategic shifts that have, or will have, a major effect on an entity’s operations and financial results would qualify for reporting as discontinued operations. Disposals that are considered to be routine in nature can no longer be reported as discontinued operations. However, a disposal may now qualify for discontinued operations reporting even if the disposed component's operations and cash flows are not eliminated from on-going operations of the disposing entity, or if post-disposal, the disposing entity still has significant continuing involvement in the component’s operations. The standard also establishes both additional disclosure requirements and expanded disclosures regarding on-going involvement an entity may have with a discontinued operation after its disposal. The guidance is effective prospectively for all public company disposals (or component reclassifications to held-for-sale) that occur within annual periods beginning on or after December 15, 2014. Early adoption is permitted, but only for disposals (or component reclassifications to held-for-sale) that have not been reported in financial statements issued or available for issuance prior to the effective date. This guidance is not expected to have a significant impact on the Company's financial condition, results of operations or cash flows.

Sale_of_Life_Reinsurance_Subsi1

Sale of Life Reinsurance Subsidiary (Tables)	6 Months Ended
	Jun. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Impact of Life Retro Arrangements	'
	The impact of the Life Retro Arrangements on the Company's results from the completion of the transaction on May 30, 2014 through June 30, 2014 were as follows:
	Impact of Life Retro Arrangements	May 30 to June 30
	(U.S. dollars in thousands)	2014
	Underwriting profit (loss)	$	—
	Net investment income - Life Funds Withheld Assets	19,165
	Net realized gains (losses) on investments sold - Life Funds Withheld Assets	624
	OTTI on investments - Life Funds Withheld Assets	(8,771		)
	Other income and expenses	(19		)
	Net realized and unrealized gains (losses) on life retrocession embedded derivative	(17,546		)
	Net income (loss)	$	(6,547	)
	Change in net unrealized gains (losses) on investments - Life Funds Withheld Assets, net of tax	12,297
	Change in cumulative translation adjustment - Life Funds Withheld Assets, net of tax	(5,750		)
	Comprehensive income (loss)	$	—

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2014
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 at June 30, 2014 and December 31, 2013 by level within the fair value hierarchy:
	30-Jun-14	Quoted Prices			Significant			Significant			Collateral			Balance at
	(U.S. dollars in thousands)	in Active			Other			Other			and			30-Jun-14
		Markets for			Observable			Unobservable			Counterparty
		Identical Assets			Inputs			Inputs			Netting
		(Level 1)			(Level 2)			(Level 3)
	Assets
	Fixed maturities - Available for Sale ("AFS") - Excluding Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported	$	—		$	2,084,294		$	—		$	—		$	2,084,294
	Corporate (1)	—			9,723,691			3,933			—			9,727,624
	Residential mortgage-backed securities – Agency (“RMBS - Agency”)	—			3,296,150			6,896			—			3,303,046
	Residential mortgage-backed securities – Non-Agency (“RMBS - Non-Agency”)	—			415,492			11			—			415,503
	Commercial mortgage-backed securities (“CMBS”)	—			1,122,342			1,945			—			1,124,287
	Collateralized debt obligations (“CDO”)	—			5,249			732,824			—			738,073
	Other asset-backed securities (2)	—			1,298,568			11,704			—			1,310,272
	U.S. States and political subdivisions of the States	—			1,939,590			—			—			1,939,590
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	—			4,355,861			—			—			4,355,861
	Total fixed maturities - AFS - Excluding Funds Withheld Assets, at fair value	$	—		$	24,241,237		$	757,313		$	—		$	24,998,550
	Equity securities, at fair value (3)	603,993			384,717			—			—			988,710
	Short-term investments, at fair value (1)(4)	—			347,674			—			—			347,674
	Total investments AFS - Excluding Funds Withheld Assets	$	603,993		$	24,973,628		$	757,313		$	—		$	26,334,934
	Fixed maturities - Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported	$	—		$	18,225		$	—		$	—		$	18,225
	Corporate	—			3,017,446			—			—			3,017,446
	RMBS – Agency	—			4,023			—			—			4,023
	RMBS – Non-Agency	—			88,104			—			—			88,104
	CMBS	—			216,844			—			—			216,844
	CDO	—			—			—			—			—
	Other asset-backed securities	—			293,617			—			—			293,617
	U.S. States and political subdivisions of the States	—			—			—			—			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	—			1,806,112			—			—			1,806,112
	Total fixed maturities - AFS - Life Funds Withheld Assets, at fair value	$	—		$	5,444,371		$	—		$	—		$	5,444,371
	Total investments - AFS, at fair value	$	603,993		$	30,417,999		$	757,313		$	—		$	31,779,305
	Cash equivalents (5)	1,792,096			464,544			—			—			2,256,640
	Cash equivalents - Life Funds Withheld Assets	646			122,393			—			—			123,039
	Other investments (6)	—			804,268			124,475			—			928,743
	Other assets (7)	—			48,117			12,453			(1,240		)	59,330
	Total assets accounted for at fair value	$	2,396,735		$	31,857,321		$	894,241		$	(1,240	)	$	35,147,057
	Liabilities
	Financial instruments sold, but not yet purchased (8)	$	1,854		$	29,296		$	—		$	—		$	31,150
	Other liabilities (7)	—			38,277			31,363			(1,240		)	68,400
	Total liabilities accounted for at fair value	$	1,854		$	67,573		$	31,363		$	(1,240	)	$	99,550
	31-Dec-13	Quoted Prices			Significant			Significant			Collateral			Balance at
	(U.S. dollars in thousands)	in Active			Other			Other			and			December 31,
		Markets for			Observable			Unobservable			Counterparty			2013
		Identical Assets			Inputs			Inputs			Netting
		(Level 1)			(Level 2)			(Level 3)
	Assets
	U.S. Government and Government - Related/Supported	$	—		$	2,501,851		$	—		$	—		$	2,501,851
	Corporate (1)	—			11,094,257			31,573			—			11,125,830
	RMBS – Agency	—			3,535,649			10,473			—			3,546,122
	RMBS – Non-Agency	—			398,759			9			—			398,768
	CMBS	—			1,234,262			12,533			—			1,246,795
	CDO	—			7,060			710,253			—			717,313
	Other asset-backed securities (2)	—			1,230,227			11,877			—			1,242,104
	U.S. States and political subdivisions of the States	—			1,845,812			—			—			1,845,812
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	—			4,875,541			—			—			4,875,541
	Total fixed maturities, at fair value	$	—		$	26,723,418		$	776,718		$	—		$	27,500,136
	Equity securities, at fair value (3)	540,331			499,906			—			—			1,040,237
	Short-term investments, at fair value (1)(4)	—			454,273			2,015			—			456,288
	Total investments available for sale	$	540,331		$	27,677,597		$	778,733		$	—		$	28,996,661
	Cash equivalents (5)	834,514			226,636			—			—			1,061,150
	Other investments (6)	—			757,110			113,472			—			870,582
Other assets (7)	—			27,487			—			(1,342		)	26,145
Total assets accounted for at fair value	$	1,374,845		$	28,688,830		$	892,205		$	(1,342	)	$	30,954,538
Liabilities
Financial instruments sold, but not yet purchased (8)	$	—		$	28,861		$	—		$	—		$	28,861
Other liabilities (7)	—			76,375			29,110			(1,342		)	104,143
Total liabilities accounted for at fair value	$	—		$	105,236		$	29,110		$	(1,342	)	$	133,004
____________
-1	Included within Corporate 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 $155.9 million and $154.6 million and an amortized cost of $143.6 million and $147.7 million at June 30, 2014 and December 31, 2013, 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	The Company invests in covered bonds (“Covered Bonds”). Covered Bonds are senior secured debt instruments issued by financial institutions and backed by over-collateralized pools of public sector or mortgage loans. At June 30, 2014 and December 31, 2013, Covered Bonds with a fair value of $763.6 million and $553.1 million, respectively, are included within Other asset-backed securities.
-3	Included within Equity securities are investments in fixed income funds with a fair value of $92.1 million and $87.4 million at June 30, 2014 and December 31, 2013, respectively.
-4	Short-term investments consist primarily of Corporate securities and U.S. and Non-U.S. Government and Government-Related/Supported securities.
-5	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.
-6	The Other investments balance excludes certain structured transactions including certain investments in project finance transactions, 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 $275.8 million at June 30, 2014 and $294.0 million at December 31, 2013, are carried at amortized cost. For further information, see Item 8, Note 7, “Other Investments,” to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2013.
-7	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.
-8	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 June 30, 2014
	(U.S. dollars in thousands)	Corporate			RMBS - Agency			RMBS - Non			CMBS			CDO
								Agency
	Balance, beginning of period	$	4,382		$	8,928		$	11		$	5,926		$	718,827
	Realized gains (losses)	35			6			—			2			875
	Movement in unrealized gains (losses)	(93		)	(13		)	—			(1		)	8,331
	Purchases and issuances	8			—			—			1,376			75,201
	Sales	—			—			—			—			(30,892		)
	Settlements	(399		)	(2,025		)	—			(5,358		)	(39,518		)
	Transfers into Level 3	—			—			—			—			—
	Transfers out of Level 3	—			—			—			—			—
	Fixed maturities to short-term investments classification change	—			—			—			—			—
	Balance, end of period	$	3,933		$	6,896		$	11		$	1,945		$	732,824
	Movement in total gains (losses) above relating to instruments still held at the reporting date	$	(58	)	$	(6	)	$	—		$	—		$	8,247
		Level 3 Assets and Liabilities -Three Months Ended June 30, 2014
	(U.S. dollars in thousands)	Other asset-			Non-US Sovereign			Short-term			Other investments			Derivative Contracts
		backed			Government,			investments						- Net
		securities			Provincial,
					Supranational and
					Government
					Related/Supported
	Balance, beginning of period	$	10,673		$	—		$	—		$	116,418		$	(32,496	)
	Realized gains (losses)	(5		)	—			—			5,127			—
	Movement in unrealized gains (losses)	144			—			—			(1,779		)	13,586
	Purchases and issuances	3,000			—			—			9,997			—
	Sales	—			—			—			—			—
	Settlements	(2,108		)	—			—			(5,288		)	—
	Transfers into Level 3	—			—			—			—			—
	Transfers out of Level 3	—			—			—			—			—
	Fixed maturities to short-term investments classification change	—			—			—			—			—
	Balance, end of period	$	11,704		$	—		$	—		$	124,475		$	(18,910	)
	Movement in total gains (losses) above relating to instruments still held at the reporting date	$	140		$	—		$	—		$	3,348		$	13,586
		Level 3 Assets and Liabilities -Three Months Ended June 30, 2013
	(U.S. dollars in thousands)	Corporate			RMBS - Agency			RMBS - Non			CMBS			CDO
								Agency
	Balance, beginning of period	$	40,815		$	19,107		$	103		$	25,012		$	702,904
	Realized gains (losses)	(69		)	(2		)	—			—			(55		)
	Movement in unrealized gains (losses)	426			(19		)	—			(19		)	14,491
	Purchases and issuances	—			—			3,326			—			5,362
	Sales	—			—			—			—			—
	Settlements	(7,139		)	(872		)	(18		)	(570		)	(16,689		)
	Transfers into Level 3	—			—			—			—			—
	Transfers out of Level 3	(1,860		)	—			—			—			—
	Fixed maturities to short-term investments classification change	—			—			—			—			—
	Balance, end of period	$	32,173		$	18,214		$	3,411		$	24,423		$	706,013
	Movement in total gains (losses) above relating to instruments still held at the reporting date	$	424		$	(22	)	$	(1	)	$	(19	)	$	13,804
		Level 3 Assets and Liabilities -Three Months Ended June 30, 2013
	(U.S. dollars in thousands)	Other asset-			Non-US Sovereign			Short-term			Other investments			Derivative Contracts
		backed			Government,			investments						- Net
		securities			Provincial,
					Supranational and
					Government
					Related/Supported
	Balance, beginning of period	$	35,887		$	—		$	2,017		$	113,322		$	(32,550	)
	Realized gains (losses)	(13		)	—			(10		)	2,872			—
	Movement in unrealized gains (losses)	(512		)	—			(8		)	932			3,176
	Purchases and issuances	—			—			—			1,002			—
	Sales	—			—			—			—			—
	Settlements	(1,317		)	—			—			(14,284		)	—
	Transfers into Level 3	—			—			—			—			—
	Transfers out of Level 3	(6,506		)	—			—			—			—
	Fixed maturities to short-term investments classification change	—			—			—			—			—
	Balance, end of period	$	27,539		$	—		$	1,999		$	103,844		$	(29,374	)
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	(525	)	$	—		$	(18	)	$	3,812		$	3,176
	Level 3 Assets and Liabilities - Six Months Ended June 30, 2014
(U.S. dollars in thousands)	Corporate			RMBS - Agency			RMBS - Non			CMBS			CDO
							Agency
Balance, beginning of period	$	31,573		$	10,473		$	9		$	12,533		$	710,253
Realized gains (losses)	155			6			—			3			2,456
Movement in unrealized gains (losses)	(96		)	(13		)	2			(3		)	12,013
Purchases and issuances	1,443			—			—			1,376			103,015
Sales	—			—			—			—			(40,824		)
Settlements	(5,513		)	(2,598		)	—			(11,964		)	(54,089		)
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	(23,629		)	(972		)	—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	3,933		$	6,896		$	11		$	1,945		$	732,824
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	90		$	(6	)	$	2		$	—		$	13,216
	Level 3 Assets and Liabilities - Six Months Ended June 30, 2014
(U.S. dollars in thousands)	Other asset-			Non-US Sovereign			Short-term			Other investments			Derivative Contracts
	backed			Government,			investments						- Net
	securities			Provincial,
				Supranational and
				Government
				Related/Supported
Balance, beginning of period	$	11,877		$	—		$	2,015		$	113,472		$	(29,110	)
Realized gains (losses)	(20		)	—			—			8,691			—
Movement in unrealized gains (losses)	206			—			(15		)	(282		)	10,200
Purchases and issuances	3,000			—			—			21,086			—
Sales	—			—			—			—			—
Settlements	(3,359		)	—			(2,000		)	(18,492		)	—
Transfers into Level 3	—			—						—			—
Transfers out of Level 3	—			—			—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	11,704		$	—		$	—		$	124,475		$	(18,910	)
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	186		$	—		$	—		$	8,409		$	10,200
	Level 3 Assets and Liabilities - Six Months Ended June 30, 2013
(U.S. dollars in thousands)	Corporate			RMBS - Agency			RMBS - Non			CMBS			CDO
							Agency
Balance, beginning of period	$	30,098		$	32,005		$	116		$	25,347		$	701,736
Realized gains (losses)	(71		)	11			—			—			301
Movement in unrealized gains (losses)	630			(37		)	—			(18		)	35,746
Purchases and issuances	10,621			—			3,326			—			5,362
Sales	—			(535		)	—			—			—
Settlements	(7,245		)	(1,765		)	(31		)	(906		)	(37,132		)
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	(1,860		)	(11,465		)	—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	32,173		$	18,214		$	3,411		$	24,423		$	706,013
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	627		$	(40	)	$	(1	)	$	(18	)	$	34,278
	Level 3 Assets and Liabilities - Six Months Ended June 30, 2013
(U.S. dollars in thousands)	Other asset-			Non-US Sovereign			Short-term			Other investments			Derivative Contracts
	backed			Government,			investments						- Net
	securities			Provincial,
				Supranational and
				Government
				Related/Supported
Balance, beginning of period	$	18,128		$	—		$	—		$	115,272		$	(36,247	)
Realized gains (losses)	38			—			(10		)	5,787			—
Movement in unrealized gains (losses)	963			—			(8		)	(970		)	6,873
Purchases and issuances	21,686			—			2,017			2,907			—
Sales	—			—			—			—			—
Settlements	(6,770		)	—			—			(19,152		)	—
Transfers into Level 3	—			—			—			—			—
Transfers out of Level 3	(6,506		)	—			—			—			—
Fixed maturities to short-term investments classification change	—			—			—			—			—
Balance, end of period	$	27,539		$	—		$	1,999		$	103,844		$	(29,374	)
Movement in total gains (losses) above relating to instruments still held at the reporting date	$	(516	)	$	—		$	(18	)	$	4,808		$	6,873
Financial Instruments Not Carried at Fair Value	'
		June 30, 2014						December 31, 2013
	(U.S. dollars in thousands)	Carrying			Fair			Carrying			Fair
		Value			Value			Value			Value
	Fixed maturities, held to maturity	$	—		$	—		$	2,858,695		$	3,131,235
	Other investments - structured transactions	275,821			299,661			294,048			296,799
	Financial Assets	$	275,821		$	299,661		$	3,152,743		$	3,428,034
	Deposit liabilities	$	1,288,376		$	1,520,108		$	1,509,243		$	1,718,394
	Notes payable and debt	2,262,452			2,511,270			2,263,203			2,429,412
	Financial Liabilities	$	3,550,828		$	4,031,378		$	3,772,446		$	4,147,806

Segment_Information_Tables

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Schedule of segment reporting, by segment	'
	Six Months Ended June 30, 2013	Insurance			Reinsurance			Total P&C			Corporate			Total
	(U.S. dollars in thousands, except ratios)										and Other (1)
	Gross premiums written	$	2,970,175		$	1,378,911		$	4,349,086		$	154,272		$	4,503,358
	Net premiums written	2,238,351			1,263,830			3,502,181			139,341			3,641,522
	Net premiums earned	2,097,634			855,109			2,952,743			139,341			3,092,084
	Net losses and loss expenses	1,371,840			408,850			1,780,690			227,720			2,008,410
	Acquisition costs	268,654			172,133			440,787			11,358			452,145
	Operating expenses (2)	378,511			80,043			458,554			4,801			463,355
	Underwriting profit (loss)	$	78,629		$	194,083		$	272,712		$	(104,538	)	$	168,174
	Net investment income - excluding Life Funds Withheld Assets							300,857			142,280			443,137
	Net investment income - Life Funds Withheld Assets										—			—
	Net results from structured products (3)	7,717			3,512			11,229			—			11,229
	Net fee income and other (4)	(3,294		)	1,152			(2,142		)	1,087			(1,055		)
	Loss on sale of life reinsurance subsidiary							—			—			—
	Net realized gains (losses) on investments - excluding Life Funds Withheld Assets							74,947			2,530			77,477
	Net realized gains (losses) on investments - Life Funds Withheld Assets							—			—			—
	Net realized and unrealized gains (losses) on derivative instruments							—			2,780			2,780
	Net realized and unrealized gains (losses) on life retrocession embedded derivative							—			—			—
	Net income (loss) from investment fund affiliates and operating affiliates (5)							—			142,587			142,587
	Exchange (gains) losses							—			(44,766		)	(44,766		)
	Corporate operating expenses							—			102,077			102,077
	Contribution from P&C and Corporate and Other							$	657,603		$	129,415		$	787,018
	Interest expense (6)										52,257			52,257
	Non-controlling interests										38,922			38,922
	Income tax expense										72,351			72,351
	Net income (loss) attributable to ordinary shareholders													$	623,488
	Ratios – P&C operations: (7)
	Loss and loss expense ratio	65.4		%	47.8		%	60.3		%
	Underwriting expense ratio	30.9		%	29.5		%	30.5		%
	Combined ratio	96.3		%	77.3		%	90.8		%
	____________
	-1	Corporate and Other includes the Company's run-off life operations.
	-2	Operating expenses exclude Corporate operating expenses, shown separately.
	-3	The net results from structured products include net investment income and interest expense of $35.9 million and $24.6 million, respectively.
	-4	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
	-5	The Company records the income related to the alternative funds and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
	-6	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments.
	-7	Ratios are based on net premiums earned from P&C operations.
	The following tables summarize the segment results for the three and six months ended June 30, 2014 and 2013:
	Three Months Ended June 30, 2014	Insurance			Reinsurance			Total P&C			Corporate			Total
	(U.S. dollars in thousands, except ratios)										and Other (1)
	Gross premiums written	$	1,618,405		$	493,124		$	2,111,529		$	86,710		$	2,198,239
	Net premiums written	996,880			436,446			1,433,326			58,518			1,491,844
	Net premiums earned	1,003,990			434,086			1,438,076			58,518			1,496,594
	Net losses and loss expenses	627,627			200,253			827,880			85,299			913,179
	Acquisition costs	99,863			80,874			180,737			3,882			184,619
	Operating expenses (2)	213,931			47,582			261,513			2,209			263,722
	Underwriting profit (loss)	$	62,569		$	105,377		$	167,946		$	(32,872	)	$	135,074
	Net investment income - excluding Life Funds Withheld Assets							144,555			52,118			196,673
	Net investment income - Life Funds Withheld Assets										19,165			19,165
	Net results from structured products (3)	31,645			3,240			34,885			—			34,885
	Net fee income and other (4)	(3,567		)	664			(2,903		)	45			(2,858		)
	Loss on sale of life reinsurance subsidiary							—			666,423			666,423
	Net realized gains (losses) on investments - excluding Life Funds Withheld Assets							78,505			2,339			80,844
	Net realized gains (losses) on investments - Life Funds Withheld Assets							—			(8,147		)	(8,147		)
	Net realized and unrealized gains (losses) on derivative instruments							—			11,599			11,599
	Net realized and unrealized gains (losses) on life retrocession embedded derivative							—			(17,546		)	(17,546		)
	Net income (loss) from investment fund affiliates and operating affiliates (5)							—			45,421			45,421
	Exchange (gains) losses							—			21,141			21,141
	Corporate operating expenses							—			56,495			56,495
	Contribution from P&C and Corporate and Other							422,988			(671,937		)	(248,949		)
	Interest expense (6)										32,284			32,284
	Non-controlling interests										3,682			3,682
Income tax expense										(5,654		)	(5,654		)
Net income (loss) attributable to ordinary shareholders													$	(279,261	)
Ratios – P&C operations: (7)
Loss and loss expense ratio	62.5		%	46.1		%	57.6		%
Underwriting expense ratio	31.3		%	29.6		%	30.7		%
Combined ratio	93.8		%	75.7		%	88.3		%
____________
-1	Corporate and Other includes the Company's run-off life operations.
-2	Operating expenses exclude Corporate operating expenses, shown separately.
-3	The net results from structured products include net investment income and interest expense (credit) of $16.9 million and $(18.2) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
-4	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
-5	The Company records the income related to the alternative funds and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
-6	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments.
-7	Ratios are based on net premiums earned from P&C operations.
Three Months Ended June 30, 2013	Insurance			Reinsurance			Total P&C			Corporate			Total
(U.S. dollars in thousands, except ratios)										and Other (1)
Gross premiums written	$	1,472,388		$	471,782		$	1,944,170		$	81,302		$	2,025,472
Net premiums written	1,049,163			410,809			1,459,972			73,896			1,533,868
Net premiums earned	1,058,542			429,955			1,488,497			73,896			1,562,393
Net losses and loss expenses	721,323			216,283			937,606			116,767			1,054,373
Acquisition costs	138,032			86,599			224,631			7,255			231,886
Operating expenses (2)	194,514			39,622			234,136			2,206			236,342
Underwriting profit (loss)	$	4,673		$	87,451		$	92,124		$	(52,332	)	$	39,792
Net investment income - excluding Life Funds Withheld Assets							143,818			70,592			214,410
Net investment income - Life Funds Withheld Assets										—			—
Net results from structured products (3)	3,532			2,521			6,053			—			6,053
Net fee income and other (4)	(1,355		)	520			(835		)	44			(791		)
Loss on sale of life reinsurance subsidiary							—			—			—
Net realized gains (losses) on investments - excluding Life Funds Withheld Assets							29,369			11,599			40,968
Net realized gains (losses) on investments - Life Funds Withheld Assets							—			—			—
Net realized and unrealized gains (losses) on derivative instruments							—			(5,105		)	(5,105		)
Net realized and unrealized gains (losses) on life retrocession embedded derivative							—			—			—
Net income (loss) from investment fund affiliates and operating affiliates (5)							—			79,368			79,368
Exchange (gains) losses							—			(11,331		)	(11,331		)
Corporate operating expenses							—			55,155			55,155
Contribution from P&C and Corporate and Other							270,529			60,342			330,871
Interest expense (6)										26,121			26,121
Non-controlling interests										3,180			3,180
Income tax expense										28,872			28,872
Net income (loss) attributable to ordinary shareholders													$	272,698
Ratios – P&C operations: (7)
Loss and loss expense ratio	68.1		%	50.3		%	63		%
Underwriting expense ratio	31.5		%	29.4		%	30.8		%
Combined ratio	99.6		%	79.7		%	93.8		%
____________
-1	Corporate and Other includes the Company's run-off life operations.
-2	Operating expenses exclude Corporate operating expenses, shown separately.
-3	The net results from structured products include net investment income and interest expense of $18.1 million and $12.1 million, respectively.
-4	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
-5	The Company records the income related to the alternative funds and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
-6	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance segments.
-7	Ratios are based on net premiums earned from P&C operations.
Six Months Ended June 30, 2014	Insurance			Reinsurance			Total P&C			Corporate			Total
(U.S. dollars in thousands, except ratios)										and Other (1)
Gross premiums written	$	3,189,331		$	1,350,837		$	4,540,168		$	171,007		$	4,711,175
Net premiums written	2,124,247			1,228,619			3,352,866			134,829			3,487,695
Net premiums earned	1,996,430			854,174			2,850,604			134,829			2,985,433
Net losses and loss expenses	1,266,820			392,565			1,659,385			198,886			1,858,271
Acquisition costs	204,863			168,109			372,972			11,061			384,033
Operating expenses (2)	416,984			88,443			505,427			5,397			510,824
Underwriting profit (loss)	$	107,763		$	205,057		$	312,820		$	(80,515	)	$	232,305
Net investment income - excluding Life Funds Withheld Assets							288,082			123,010			411,092
Net investment income - Life Funds Withheld Assets										19,165			19,165
Net results from structured products (3)	36,535			6,303			42,838			—			42,838
Net fee income and other (4)	(4,779		)	1,337			(3,442		)	90			(3,352		)
Loss on sale of life reinsurance subsidiary							—			666,423			666,423
Net realized gains (losses) on investments - excluding Life Funds Withheld Assets							96,171			3,902			100,073
Net realized gains (losses) on investments - Life Funds Withheld Assets							—			(8,147		)	(8,147		)
Net realized and unrealized gains (losses) on derivative instruments							—			13,409			13,409
Net realized and unrealized gains (losses) on life retrocession embedded derivative							—			(17,546		)	(17,546		)
Net income (loss) from investment fund affiliates and operating affiliates (5)							—			125,009			125,009
Exchange (gains) losses							—			31,582			31,582
Corporate operating expenses							—			107,833			107,833
Contribution from P&C and Corporate and Other							$	736,469		$	(627,461	)	$	109,008
Interest expense (6)										64,444			64,444
Non-controlling interests										39,441			39,441
Income tax expense										28,667			28,667
Net income (loss) attributable to ordinary shareholders													$	(23,544	)
Ratios – P&C operations: (7)
Loss and loss expense ratio	63.5		%	46		%	58.2		%
Underwriting expense ratio	31.1		%	30		%	30.8		%
Combined ratio	94.6		%	76		%	89		%
____________
-1	Corporate and Other includes the Company's run-off life operations.
-2	Operating expenses exclude Corporate operating expenses, shown separately.
-3	The net results from structured products include net investment income and net interest expense (credit) of $35.7 million and $(7.4) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
-4	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
-5	The Company records the income related to the alternative funds and to the private investment and operating fund affiliates on a one-month and three-month lag, respectively.
-6	Interest expense excludes interest expense related to deposit liabilities recorded in the Insurance and Reinsurance se
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 months ended June 30, 2014 and 2013:
	Three Months Ended June 30, 2014	Insurance			Reinsurance			Corporate			Total
	(U.S. dollars in thousands)							and Other
	P&C Operations:
	Professional	$	267,509		$	44,239		$	—		$	311,748
	Casualty	358,990			82,929			—			441,919
	Property catastrophe	—			112,562			—			112,562
	Property	142,874			142,337			—			285,211
	Marine, energy, aviation and satellite	—			21,065			—			21,065
	Specialty	179,948			—			—			179,948
	Other (1)	54,669			30,954			—			85,623
	Total P&C Operations	$	1,003,990		$	434,086		$	—		$	1,438,076
	Corporate and Other:
	Run-off Life operations - Annuity	$	—		$	—		$	21,565		$	21,565
	Run-off Life operations - Other Life	—			—			36,953			36,953
	Total Corporate and Other	$	—		$	—		$	58,518		$	58,518
	Total	$	1,003,990		$	434,086		$	58,518		$	1,496,594
	Three Months Ended June 30, 2013	Insurance			Reinsurance			Corporate			Total
	(U.S. dollars in thousands)							and Other
	P&C Operations:
	Professional	$	349,812		$	50,978		$	—		$	400,790
	Casualty	338,437			76,544			—			414,981
	Property catastrophe	—			129,361			—			129,361
	Property	135,089			132,501			—			267,590
	Marine, energy, aviation and satellite	—			24,588			—			24,588
	Specialty	181,131			—			—			181,131
	Other (1)	54,073			15,983			—			70,056
	Total P&C Operations	$	1,058,542		$	429,955		$	—		$	1,488,497
	Corporate and Other:
	Run-off Life operations - Annuity	$	—		$	—		$	30,087		$	30,087
	Run-off Life operations - Other Life	—			—			43,809			43,809
	Total Corporate and Other	$	—		$	—		$	73,896		$	73,896
	Total	$	1,058,542		$	429,955		$	73,896		$	1,562,393
	____________
	-1	Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain other discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines.
	The following tables summarize the Company’s net premiums earned by line of business for the six months ended June 30, 2014:
	Six Months Ended June 30, 2014	Insurance			Reinsurance			Corporate			Total
	(U.S. dollars in thousands)							and Other
	P&C Operations:
	Professional	$	542,936		$	94,343		$	—		$	637,279
	Casualty	702,994			159,650			—			862,644
	Property catastrophe	—			220,999			—			220,999
	Property	282,607			277,576			—			560,183
	Marine, energy, aviation and satellite	—			44,579			—			44,579
	Specialty	356,857			—			—			356,857
	Other (1)	111,036			57,027			—			168,063
	Total P&C Operations	$	1,996,430		$	854,174		$	—		$	2,850,604
	Corporate and Other:
	Run-off Life operations - Annuity	$	—		$	—		$	53,362		$	53,362
	Run-off Life operations - Other Life	—			—			81,467			81,467
	Total Corporate and Other	$	—		$	—		$	134,829		$	134,829
	Total	$	1,996,430		$	854,174		$	134,829		$	2,985,433
	Six Months Ended June 30, 2013	Insurance			Reinsurance			Corporate			Total
	(U.S. dollars in thousands)							and Other
	P&C Operations:
	Professional	$	700,650		$	96,414		$	—		$	797,064
	Casualty	665,855			153,525			—			819,380
	Property catastrophe	—			243,003			—			243,003
	Property	259,539			273,770			—			533,309
	Marine, energy, aviation and satellite	—			52,428			—			52,428
	Specialty	364,096			—			—			364,096
	Other (1)	107,494			35,969			—			143,463
	Total P&C Operations	$	2,097,634		$	855,109		$	—		$	2,952,743
Corporate and Other:
Run-off Life operations - Annuity	$	—		$	—		$	59,771		$	59,771
Run-off Life operations - Other Life	—			—			79,570			79,570
Total Corporate and Other	$	—		$	—		$	139,341		$	139,341
Total	$	2,097,634		$	855,109		$	139,341		$	3,092,084
____________
-1	Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain other discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines.

Investments_Tables

Investments (Tables)	6 Months Ended
	Jun. 30, 2014
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 other-than-temporary impairments (“OTTI”) recorded in accumulated other comprehensive income (“AOCI”) of the Company’s AFS investments, the Life Funds Withheld Assets designated as AFS, and HTM investments at June 30, 2014 and December 31, 2013, were as follows:
	30-Jun-14	Cost or			Gross			Gross Unrealized Losses			Fair Value			Non-credit Related OTTI (1)
	(U.S. dollars in thousands)	Amortized			Unrealized
		Cost			Gains
	Fixed maturities - AFS - Excluding Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported (2)	$	2,033,152		$	60,408		$	(9,266	)	$	2,084,294		$	—
	Corporate (3) (4)	9,345,654			425,093			(43,123		)	9,727,624			(4,758		)
	RMBS – Agency	3,218,551			104,874			(20,379		)	3,303,046			—
	RMBS – Non-Agency	395,629			41,054			(21,180		)	415,503			(70,645		)
	CMBS	1,098,149			33,562			(7,424		)	1,124,287			(2,561		)
	CDO	763,146			3,656			(28,729		)	738,073			(1,812		)
	Other asset-backed securities (5)	1,271,201			42,158			(3,087		)	1,310,272			(2,058		)
	U.S. States and political subdivisions of the States	1,836,889			109,258			(6,557		)	1,939,590			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported (2)	4,264,089			117,877			(26,105		)	4,355,861			—
	Total fixed maturities - AFS - Excluding Life Funds Withheld Assets	$	24,226,460		$	937,940		$	(165,850	)	$	24,998,550		$	(81,834	)
	Total short-term investments (2)	$	347,473		$	972		$	(771	)	$	347,674		$	—
	Total equity securities (6)	$	839,716		$	151,618		$	(2,624	)	$	988,710		$	—
	Total investments - AFS - Excluding Life Funds Withheld Assets	$	25,413,649		$	1,090,530		$	(169,245	)	$	26,334,934		$	(81,834	)
	Fixed maturities - AFS - Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported	$	16,356		$	1,869		$	—		$	18,225		$	—
	Corporate	2,722,907			294,539			—			3,017,446			—
	RMBS – Agency	3,990			33			—			4,023			—
	RMBS – Non-Agency	78,804			9,300			—			88,104			—
	CMBS	198,576			18,268			—			216,844			—
	CDO	—			—			—			—			—
	Other asset-backed securities	271,691			21,926			—			293,617			—
	U.S. States and political subdivisions of the States	—			—			—			—			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	1,546,747			259,365			—			1,806,112			—
	Total fixed maturities - AFS - Life Funds Withheld Assets	$	4,839,071		$	605,300		$	—		$	5,444,371		$	—
	Total investments - AFS	$	30,252,720		$	1,695,830		$	(169,245	)	$	31,779,305		$	(81,834	)
	Total fixed maturities - HTM	$	—		$	—		$	—		$	—		$	—
	___________
	-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	U.S. Government and Government-Related/Supported, Non-U.S. Sovereign Government, Provincials, Supranationals and Government-Related/Supported and Total short-term investments includes government-related securities with an amortized cost of $1,679.1 million and fair value of $1,721.8 million and U.S. Agencies with an amortized cost of $230.2 million and fair value of $256.8 million.
	-3	Included within Corporate 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 $155.9 million and an amortized cost of $143.6 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 values of these notes.
	-4	Included within Corporate are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions. These securities have a fair value of $28.1 million and an amortized cost of $32.6 million.
	-5	Covered Bonds with an amortized cost of $737.0 million and a fair value of $763.6 million are included within Other asset-backed securities to align the Company's classification to market indices.
	-6	Included within Total equity securities are investments in fixed income funds with a fair value of $92.1 million and an amortized cost of $92.1 million.
	31-Dec-13	Cost or			Gross			Gross Unrealized Losses			Fair Value			Non-credit Related OTTI (1)
	(U.S. dollars in thousands)	Amortized			Unrealized
		Cost			Gains
	Fixed maturities - AFS
	U.S. Government and Government-Related/Supported (2)	$	2,484,193		$	51,701		$	(34,043	)	$	2,501,851		$	—
	Corporate (3) (4)	10,802,332			433,097			(109,599		)	11,125,830			(4,758		)
	RMBS – Agency	3,540,101			68,098			(62,077		)	3,546,122			—
	RMBS – Non-Agency	396,798			33,096			(31,126		)	398,768			(74,528		)
	CMBS	1,223,313			39,255			(15,773		)	1,246,795			(2,753		)
	CDO	754,414			5,833			(42,934		)	717,313			(2,036		)
	Other asset-backed securities (5)	1,210,384			40,560			(8,840		)	1,242,104			(2,807		)
	U.S. States and political subdivisions of the States	1,821,499			55,083			(30,770		)	1,845,812			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported (2)	4,878,840			80,961			(84,260		)	4,875,541			—
	Total fixed maturities - AFS	$	27,111,874		$	807,684		$	(419,422	)	$	27,500,136		$	(86,882	)
	Total short-term investments (2)	$	455,470		$	962		$	(144	)	$	456,288		$	—
	Total equity securities (6)	$	903,201		$	154,506		$	(17,470	)	$	1,040,237		$	—
	Total investments - AFS	$	28,470,545		$	963,152		$	(437,036	)	$	28,996,661		$	(86,882	)
	Fixed maturities - HTM
	U.S. Government and Government-Related/Supported (2)	$	10,993		$	629		$	—		$	11,622		$	—
	Corporate	1,386,863			113,179			(968		)	1,499,074			—
	RMBS – Non-Agency	66,987			4,985			—			71,972			—
	CMBS	144,924			11,864			—			156,788			—
	Other asset-backed securities (5)	106,540			6,908			—			113,448			—
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported (2)	1,142,388			136,585			(642		)	1,278,331			—
	Total fixed maturities - HTM	$	2,858,695		$	274,150		$	(1,610	)	$	3,131,235		$	—
____________
-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	U.S. Government and Government-Related/Supported, Non-U.S. Sovereign Government, Provincials, Supranationals and Government-Related/Supported and Total short-term investments includes government-related securities with an amortized cost of $2,241.5 million and fair value of $2,275.6 million and U.S. Agencies with an amortized cost of $267.0 million and fair value of $284.3 million.
-3	Included within Corporate 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 $154.6 million and an amortized cost of $147.7 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 values of these notes.
-4	Included within Corporate are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions. These securities have a fair value of $282.2 million and an amortized cost of $286.2 million.
-5	Covered Bonds within Fixed maturities - AFS with an amortized cost of $526.4 million and a fair value of $553.1 million and Covered Bonds within Fixed maturities - HTM with an amortized cost of $8.6 million and a fair value of $8.7 million are included within Other asset-backed securities to align the Company's classification to market indices.
-6	Included within Total equity securities are investments in fixed income funds with a fair value of $87.4 million and an amortized cost of $100.0 million.
Contractual maturities summary	'
	The contractual maturities of AFS and HTM fixed income securities at June 30, 2014 and December 31, 2013 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.
		June 30, 2014 (1)						December 31, 2013 (1)
	(U.S. dollars in thousands)	Amortized			Fair			Amortized			Fair
		Cost			Value			Cost			Value
	Fixed maturities - AFS - Excluding Life Funds Withheld Assets
	Due less than one year	$	2,069,219		$	2,088,394		$	2,052,251		$	2,060,365
	Due after 1 through 5 years	9,384,790			9,657,635			10,075,087			10,305,986
	Due after 5 through 10 years	4,518,798			4,693,075			5,474,120			5,507,450
	Due after 10 years	1,506,977			1,668,265			2,385,406			2,475,233
		$	17,479,784		$	18,107,369		$	19,986,864		$	20,349,034
	RMBS – Agency	3,218,551			3,303,046			3,540,101			3,546,122
	RMBS – Non-Agency	395,629			415,503			396,798			398,768
	CMBS	1,098,149			1,124,287			1,223,313			1,246,795
	CDO	763,146			738,073			754,414			717,313
	Other asset-backed securities	1,271,201			1,310,272			1,210,384			1,242,104
	Total mortgage and asset-backed securities	$	6,746,676		$	6,891,181		$	7,125,010		$	7,151,102
	Total fixed maturities - AFS - Excluding Life Funds Withheld Assets	$	24,226,460		$	24,998,550		$	27,111,874		$	27,500,136
	Fixed maturities - AFS - Life Funds Withheld Assets
	Due less than one year	$	138,250		$	144,169		$	—		$	—
	Due after 1 through 5 years	680,192			725,237			—			—
	Due after 5 through 10 years	1,159,277			1,297,027			—			—
	Due after 10 years	2,308,291			2,675,350			—			—
		$	4,286,010		$	4,841,783		$	—		$	—
	RMBS – Agency	3,990			4,023			—			—
	RMBS – Non-Agency	78,804			88,104			—			—
	CMBS	198,576			216,844			—			—
	CDO	—			—			—			—
	Other asset-backed securities	271,691			293,617			—			—
	Total mortgage and asset-backed securities	$	553,061		$	602,588		$	—		$	—
	Total fixed maturities - AFS - Life Funds Withheld Assets	$	4,839,071		$	5,444,371		$	—		$	—
	Total fixed maturities - AFS	$	29,065,531		$	30,442,921		$	27,111,874		$	27,500,136
	Fixed maturities - HTM
	Due less than one year	$	—		$	—		$	65,651		$	66,766
	Due after 1 through 5 years	—			—			240,802			255,322
	Due after 5 through 10 years	—			—			455,633			492,095
	Due after 10 years	—			—			1,778,158			1,974,844
		$	—		$	—		$	2,540,244		$	2,789,027
	RMBS – Non-Agency	—			—			66,987			71,972
	CMBS	—			—			144,924			156,788
	Other asset-backed securities	—			—			106,540			113,448
	Total mortgage and asset-backed securities	$	—		$	—		$	318,451		$	342,208
	Total fixed maturities - HTM	$	—		$	—		$	2,858,695		$	3,131,235
	____________
	-1	Included in the table above within Fixed Maturities - AFS - Excluding Life Funds Withheld Assets, are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions, at their fair values of $28.1 million and $282.2 million at June 30, 2014 and December 31, 2013, respectively. These securities are reflected in the table based on their call date and have net unrealized losses of $4.5 million and $4.0 million at June 30, 2014 and December 31, 2013, respectively.
Summary of unrealized losses	'
	The following is an analysis of how long the AFS and HTM securities at June 30, 2014 and December 31, 2013 had been in a continual unrealized loss position:
		Less than 12 months						Equal to or greater
								than 12 months
	30-Jun-14	Fair			Gross			Fair			Gross
	(U.S. dollars in thousands)	Value			Unrealized			Value			Unrealized
					Losses						Losses
	Fixed maturities and short-term investments - AFS - Excluding Life Funds Withheld Assets
	U.S. Government and Government-Related/Supported	$	155,192		$	(1,345	)	$	455,830		$	(7,926	)
	Corporate	510,313			(4,910		)	820,499			(38,302		)
	RMBS – Agency	28,954			(123		)	652,745			(20,256		)
	RMBS – Non-Agency	26,501			(374		)	216,406			(20,806		)
	CMBS	65,205			(197		)	202,685			(7,227		)
	CDO	69,479			(268		)	492,272			(28,461		)
	Other asset-backed securities	60,338			(130		)	79,464			(2,957		)
	U.S. States and political subdivisions of the States	32,636			(260		)	222,479			(6,297		)
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	548,628			(6,517		)	515,159			(20,265		)
	Total fixed maturities and short-term investments - AFS - Excluding Life Funds Withheld Assets	$	1,497,246		$	(14,124	)	$	3,657,539		$	(152,497	)
	Total fixed maturities and short-term investments - AFS - Life Funds Withheld Assets	$	—		$	—		$	—		$	—
	Total fixed maturities and short-term investments - AFS	$	1,497,246		$	(14,124	)	$	3,657,539		$	(152,497	)
	Total equity securities	$	46,158		$	(2,624	)	$	—		$	—
	Total fixed maturities - HTM	$	—		$	—		$	—		$	—
		Less than 12 months						Equal to or greater
								than 12 months
	31-Dec-13	Fair			Gross			Fair			Gross
	(U.S. dollars in thousands)	Value			Unrealized			Value			Unrealized
					Losses						Losses
	Fixed maturities and short-term investments - AFS
	U.S. Government and Government-Related/Supported	$	1,333,704		$	(30,474	)	$	44,158		$	(3,614	)
	Corporate	2,756,235			(59,497		)	513,106			(50,160		)
	RMBS – Agency	1,485,261			(50,362		)	169,704			(11,715		)
	RMBS – Non-Agency	14,204			(604		)	240,946			(30,522		)
	CMBS	432,820			(6,816		)	107,192			(8,957		)
	CDO	58,239			(217		)	574,613			(42,717		)
	Other asset-backed securities	196,639			(2,149		)	96,528			(6,691		)
	U.S. States and political subdivisions of the States	463,974			(23,124		)	64,324			(7,646		)
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	2,130,792			(56,866		)	306,873			(27,435		)
	Total fixed maturities and short-term investments - AFS	$	8,871,868		$	(230,109	)	$	2,117,444		$	(189,457	)
	Total equity securities	$	155,453		$	(17,470	)	$	—		$	—
	Fixed maturities - HTM
	Corporate	$	46,034		$	(941	)	$	642		$	(27	)
	Non-U.S. Sovereign Government, Provincial, Supranational and Government-Related/Supported	—			—			11,894			(642		)
	Total fixed maturities - HTM	$	46,034		$	(941	)	$	12,536		$	(669	)
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 June 30,						Six months ended June 30,
	(U.S. dollars in thousands)	2014			2013			2014			2013
	Net realized gains (losses) on investments - excluding Life Funds Withheld Assets:
	Gross realized gains	$	118,947		$	64,865		$	170,160		$	138,038
	Gross realized losses on investments sold	(13,487		)	(21,508		)	(41,744		)	(53,534		)
	OTTI on investments, net of amounts transferred to other comprehensive income	(24,616		)	(2,389		)	(28,343		)	(7,027		)
		$	80,844		$	40,968		$	100,073		$	77,477
	Net realized gains (losses) on investments - Life Funds Withheld Assets:
	Gross realized gains	$	624		$	—		$	624		$	—
	Gross realized losses on investments sold	—			—			—			—
	OTTI on investments, net of amounts transferred to other comprehensive income	(8,771		)	—			(8,771		)	—
		$	(8,147	)	$	—		$	(8,147	)	$	—
	Total net realized gains (losses) on investments	$	72,697		$	40,968		$	91,926		$	77,477
Credit loss impairments on fixed inmcome securities rollforward	'
	The following table sets forth the amount of credit loss impairments on fixed income securities held by the Company as of the dates or the periods indicated, for which a portion of the OTTI loss was recognized in OCI, and the corresponding changes in such amounts.
	Credit Loss Impairments	Three months ended June 30,						Six months ended June 30,
	(U.S. dollars in thousands)	2014			2013			2014			2013
	Opening balance at beginning of indicated period	$	171,382		$	260,066		$	174,805		$	268,707
	Credit loss impairment recognized in the current period on securities not previously impaired	30			27			41			527
	Credit loss impairments previously recognized on securities which matured, paid down, prepaid or were sold during the period	(3,322		)	(55,144		)	(7,571		)	(61,619		)
	Credit loss impairments previously recognized on securities impaired to fair value during the period	—			—			—			—
	Additional credit loss impairments recognized in the current period on securities previously impaired	892			1,996			3,153			4,300
	Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	(3,105		)	(4,083		)	(4,551		)	(9,053		)
	Balance at June 30,	$	165,877		$	202,862		$	165,877		$	202,862

Derivative_Instruments_Tables

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2014
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 at June 30, 2014 and December 31, 2013:
		June 30, 2014													December 31, 2013
	(U.S. dollars in thousands)	Asset				Asset			Liability			Liability			Asset		Asset		Liability		Liability
		Derivative				Derivative			Derivative			Derivative			Derivative		Derivative		Derivative		Derivative
		Notional				Fair Value			Notional			Fair Value			Notional		Fair Value		Notional		Fair Value
		Amount				-1			Amount			-1			Amount		-1		Amount		-1
	Derivatives designated as hedging instruments:
	Foreign exchange contracts	$	891,217			$	45,597		$	1,315,385		$	35,265		$	1,005,610	$	26,098	$	2,572,227	$	70,462
	Derivatives not designated as hedging instruments:
	Investment Related Derivatives:
	Interest rate exposure	$	1,295,267			$	259		$	28,090		$	—		$	30,702	$	266	$	10,259	$	8
	Foreign exchange exposure	190,870				1,914			105,797			3,004			17,497		12		50,614		680
	Credit exposure	4,566				3			14,270			9,988			—		—		340,020		15,128
	Financial market exposure	46,645				344			43,468			—			58,232		1,111		14,821		77
	Financial Operations Derivatives: (2)
	Credit exposure	—				—			41,346			8,930			—		—		44,234		4,190
	Other Non-Investment Derivatives:
	Guaranteed minimum income benefit contract	50,802				12,453			50,802			12,453			—		—		53,564		14,940
	Modified coinsurance funds withheld contracts (3)	65,721				—			5,659,644			—			66,369		—		—		—
	Total derivatives not designated as hedging instruments	$	1,653,871			$	14,973		$	5,943,417		$	34,375		$	172,800	$	1,389	$	513,512	$	35,023
	____________
	-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 intentions to settle the contracts on a net basis.
	-2	Financial operations derivatives represent interests in variable interest entities as described in Note 12, “Variable Interest Entities".
	-3	The fair value movements in derivative assets and liabilities relating to modified coinsurance funds withheld contracts are included within the 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.
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 paid relating to derivative liabilities contained in the consolidated balance sheets at June 30, 2014 and December 31, 2013:
												Gross Amounts Not Offset in the Balance Sheets
	30-Jun-14	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
	(U.S. dollars in thousands)
	Derivative Assets	$	60,570			$	1,240		$	59,330		$	—		$	3,160	$	56,170
	Derivative Liabilities	$	69,640			$	1,240		$	68,400		$	—		$	—	$	68,400
	31-Dec-13
	(U.S. dollars in thousands)
	Derivative Assets	$	27,487			$	1,342		$	26,145		$	—		$	—	$	26,145
	Derivative Liabilities	$	105,485			$	1,342		$	104,143		$	—		$	19,847	$	84,296
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 three and six months ended June 30, 2014 and 2013:
					Hedged Items - Amount of Gain/(Loss) Recognized in Income Attributable to Risk
	Derivatives Designated as Fair Value Hedges:	Gain/(Loss)				Fixed Maturity			Ineffective
	Three Months Ended June 30, 2014	Recognized				Investments			Portion of
	(U.S. dollars in thousands)	in Income on							Hedging
		Derivative							Relationship -
									Gain/(Loss)
	Interest rate exposure	$	—
	Foreign exchange exposure	(9,132		)
	Total	$	(9,132	)		$	7,082		$	(2,050	)
	Three Months Ended June 30, 2013
	(U.S. dollars in thousands)
	Interest rate exposure	$	—
	Foreign exchange exposure	(5,002		)
	Total	$	(5,002	)		$	4,496		$	(506	)
	Six Months Ended June 30, 2014
	(U.S. dollars in thousands)
	Interest rate exposure	$	—
	Foreign exchange exposure	(15,663		)
	Total	$	(15,663	)		$	15,407		$	(256	)
	Six Months Ended June 30, 2013
	(U.S. dollars in thousands)
	Interest rate exposure	$	—
	Foreign exchange exposure	25,243
	Total	$	25,243			$	(24,274	)	$	969
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 three and six months ended June 30, 2014 and 2013, as well as the remaining balance of fair value hedges and average years remaining to maturity are shown below:
	Settlement of Fair Value Hedges - Summary	Fair Value Hedges - Notes							Fair Value Hedges - Deposit
		Payable and Debt							Liabilities
		June 30,							June 30,
	(U.S. dollars in thousands, except years)	2014				2013			2014			2013
	Cumulative reduction to interest expense	$	20,810			$	16,903		$	90,615		$	29,257
	Remaining balance	$	814			$	4,721		$	142,580		$	203,938
	Weighted average years remaining to maturity	0.2				1.2			24			24.2
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 six months ended June 30, 2014 and 2013:
	Derivative Instruments Designated as Hedges of the	Three months ended June 30,							Six months ended June 30,
	Net Investment in a Foreign Operation - Summary
	(U.S. dollars in thousands)	2014				2013			2014			2013
	Weighted average of U.S. dollar equivalent of foreign denominated net assets	$	2,270,090			$	2,588,385		$	2,478,772		$	2,556,103
	Derivative gains (losses)	$	(2,170	)		$	(6,135	)	$	(1,210	)	$	54,479
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 six months ended June 30, 2014 and 2013:
	Net Realized and Unrealized Gains (Losses) on Derivative Instruments	Three months ended June 30,							Six months ended June 30,
	(U.S. dollars in thousands)	2014				2013			2014			2013
	Investment Related Derivatives:
	Interest rate exposure	$	8,978			$	288		$	9,326		$	489
	Foreign exchange exposure	(1,490		)		(2,690		)	1,798			(4,288		)
	Credit exposure	411				(1,178		)	7			(1,994		)
	Financial market exposure	2,508				(2,736		)	3,378			2,616
	Financial Operations Derivatives:
	Credit exposure	447				1,087			(4,353		)	1,329
	Other Non-Investment Derivatives:
	Guaranteed minimum income benefit contract	633				2,306			2,257			6,002
	Modified coinsurance funds withheld contract	2,162				(1,676		)	1,252			(2,343		)
	Total gain (loss) recognized in income from derivatives not designated as hedging instruments	$	13,649			$	(4,599	)	$	13,665		$	1,811
	Amount of gain (loss) recognized in income from ineffective	(2,050		)		(506		)	(256		)	969
	portion of fair value hedges
	Net realized and unrealized gains (losses) on derivative instruments	$	11,599			$	(5,105	)	$	13,409		$	2,780
	Net realized and unrealized gains (losses) on life retrocession embedded derivative	$	(17,546	)		$	—		$	(17,546	)	$	—
Summary of credit derivative exposures	'
	An aggregate summary of the credit derivative exposure at June 30, 2014 and December 31, 2013 is as follows:
	Financial Operations Derivatives - Credit Exposure Summary:	30-Jun-14				31-Dec-13
	(U.S. dollars in thousands)
	Principal outstanding	$	39,748			$	42,080
	Interest outstanding	1,598				2,154
	Aggregate outstanding exposure	$	41,346			$	44,234
	Total liability recorded	$	8,930			$	4,190
	Weighted average contractual term to maturity	3.3 years				3.7 years
	Underlying obligations credit rating	CC				CC
Components of Life Retrocession Embedded Derivatives [Table Text Block]	'
	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:	May 30 to June 30
	(U.S. dollars in thousands)	2014
	Interest income	$	(19,944	)
	Realized and unrealized gains (losses) on Life Funds Withheld Assets	1,893
	Other	505
	Net realized and unrealized gains (losses) on life retrocession embedded derivative	$	(17,546	)
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 June 30, 2014 and December 31, 2013 were as follows:
	Contingent Credit Features - Summary:	30-Jun-14				31-Dec-13
	(U.S. dollars in thousands)
	Aggregate fair value of derivative agreements with downgrade provisions in a net liability position	$	6,728			$	47,703
	Collateral posted to counterparty	$	—			$	13,260

Share_Capital_Tables

Share Capital (Tables)	6 Months Ended
	Jun. 30, 2014
Stockholders' Equity Note [Abstract]	'
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	1.99	%
	Risk free interest rate	1.8	%
	Volatility	33.8	%
	Expected lives	6.0 years

Notes_Payable_and_Debt_and_Fin1

Notes Payable and Debt and Financing Arrangements (Tables)	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Letter of Credit Summary	'
	The Company’s letter of credit facilities and revolving credit facilities at June 30, 2014 and December 31, 2013 were as follows:
	Letter of Credit Summary:	June 30, 2014 (1)			December 31, 2013 (1)
	(U.S. dollars in thousands except percentages)
	Revolving credit facility (2)	$	1,000,000		$	1,000,000
	Available letter of credit facilities - commitments (3)	$	3,575,000		$	3,575,000
	Available letter of credit facilities - in use	$	1,870,818		$	1,895,425
	Collateralized by certain assets of the Company’s investment portfolio	67.2		%	67.6		%
	____________
	-1	At June 30, 2014 and December 31, 2013, there were seven available letter of credit facilities.
	-2	At June 30, 2014 and December 31, 2013,the revolving credit available under the November 2013 unsecured credit agreement, which provides for issuance of letters of credit and revolving credit loans up to $1 billion, was unutilized. The credit agreements entered into with Citicorp USA, Inc. in May through November 2013 (the "Citi Agreements") provide for issuance of letters of credit and revolving credit loans up to an aggregate amount of $575.0 million. At June 30, 2014, $575.0 million of letters of credit were issued under these agreements and therefore such amount is not included in the table.
	-3	The Company has the option to increase the size of the facilities under the Syndicated Credit Agreements by an additional $500 million across such facilities. The Company also has the option to increase the maximum amount of the letters of credit and revolving credit loans available under the 2013 Citi Agreements with the lender's and issuing lender's consent.

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	6 Months Ended
	Jun. 30, 2014
Related Party Transactions [Abstract]	'
Summary of related party transactions	'
	During the three and six months ended June 30, 2014 and 2013, these contracts resulted in reported net premiums written, net reported claims and reported acquisition costs as summarized below.
	(U.S. dollars in thousands)	Three months ended June 30,				Six months ended June 30,
		2014		2013		2014		2013
	Reported net premiums written	$	18,025	$	11,415	$	36,191	$	24,155
	Net losses and loss expenses incurred	$	7,692	$	6,117	$	14,301	$	11,766
	Reported acquisition costs	$	6,994	$	5,355	$	15,553	$	10,707

Computation_of_Earnings_Per_Or1

Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Calculation of earnings per share	'
	The following table sets forth the computation of basic and diluted earnings per share for the three and six months ended June 30, 2014 and 2013:
		Three Months Ended					Six Months Ended June 30,
		June 30,
	(U.S. dollars in thousands, except per share amounts)	2014			2013		2014			2013
	Basic earnings per ordinary share & ordinary share equivalents outstanding:
	Net income (loss) attributable to ordinary shareholders	$	(279,261	)	$	272,698	$	(23,544	)	$	623,488
	Weighted average ordinary shares outstanding, in thousands - basic	270,924			289,513		273,616			292,277
	Basic earnings per ordinary share & ordinary share equivalents outstanding	$	(1.03	)	$	0.94	$	(0.09	)	$	2.13
	Diluted earnings per ordinary share & ordinary share equivalents outstanding:
	Weighted average ordinary shares outstanding, in thousands - basic	270,924			289,513		273,616			292,277
	Impact of share-based compensation and certain conversion features, in thousands	—			4,820		—			4,767
	Weighted average ordinary shares outstanding, in thousands - diluted	270,924			294,333		273,616			297,044
	Diluted earnings per ordinary share & ordinary share equivalents outstanding	$	(1.03	)	$	0.93	$	(0.09	)	$	2.1
	Dividends per ordinary share	$	0.16		$	0.14	$	0.32		$	0.28

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Financial guarantee exposure summary	'
	A summary of the Company's outstanding financial guarantee exposures at June 30, 2014 and December 31, 2013 is as follows:
	Financial Guarantee Exposure Summary	30-Jun-14		31-Dec-13
	(U.S. dollars in thousands except number of contracts and term to maturity)
	Opening number of financial guarantee contracts	3		4
	Number of financial guarantee contracts matured, prepaid or commuted during the period	—		(1		)
	Closing number of financial guarantee contracts	3		3
	Principal outstanding	$	108,255	$	108,255
	Interest outstanding	$	—	$	—
	Aggregate exposure outstanding	$	108,255	$	108,255
	Total gross claim liability recorded	$	—	$	—
	Total unearned premiums and fees recorded	$	61	$	134
	Weighted average contractual term to maturity in years	25.6		26

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2014
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 six months ended June 30, 2014 and 2013 are as follows:
	Three months ended June 30, 2014	Unrealized Gains (Losses) on Investments (1)			OTTI Losses Recognized in AOCI			Foreign Currency Translation Adjustments			Underfunded Pension Liability			Cash Flow Hedge		Total
	(U.S. dollars in thousands)
	Balance, beginning of period, net of tax	$	1,032,941		$	(85,894	)	$	10,661		$	(13,270	)	$	2,223	$	946,661
	OCI before reclassifications	363,348			—			(3,621		)	(8		)	—		359,719
	Amounts reclassified from AOCI	(74,337		)	1,640			—			—			110		(72,587		)
	Tax benefit (expense)	(20,774		)	(4		)	(5,981		)	—			—		(26,759		)
	Net current period OCI - net of tax	268,237			1,636			(9,602		)	(8		)	110		260,373
	Balance, end of period, net of tax	$	1,301,178		$	(84,258	)	$	1,059		$	(13,278	)	$	2,333	$	1,207,034
	Three months ended June 30, 2013
	(U.S. dollars in thousands)
	Balance, beginning of period, net of tax	$	1,474,553		$	(116,189	)	$	65,480		$	(20,506	)	$	1,784	$	1,405,122
	OCI before reclassifications	(701,365		)	—			(25,524		)	(91		)	—		(726,980		)
	Amounts reclassified from AOCI	(55,408		)	14,440			—			—			110		(40,858		)
	Tax benefit (expense)	71,671			(2		)	1,806			—			—		73,475
	Net current period OCI - net of tax	(685,102		)	14,438			(23,718		)	(91		)	110		(694,363		)
	Balance, end of period, net of tax	$	789,451		$	(101,751	)	$	41,762		$	(20,597	)	$	1,894	$	710,759
	Six months ended June 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	628,599			—			(9,521		)	(39		)	—		619,039
	Amounts reclassified from AOCI	(96,975		)	5,049			—			—			220		(91,706		)
	Tax benefit (expense)	(52,878		)	(117		)	(3,961		)	—			—		(56,956		)
	Net current period OCI - net of tax	478,746			4,932			(13,482		)	(39		)	220		470,377
	Balance, end of period, net of tax	$	1,301,178		$	(84,258	)	$	1,059		$	(13,278	)	$	2,333	$	1,207,034
	Six months ended June 30, 2013
	(U.S. dollars in thousands)
	Balance, beginning of period, net of tax	$	1,591,210		$	(121,371	)	$	69,399		$	(20,892	)	$	1,674	$	1,520,020
	OCI before reclassifications	(789,054		)	—			(30,576		)	295			—		(819,335		)
	Amounts reclassified from AOCI	(97,102		)	19,625			—			—			220		(77,257		)
	Tax benefit (expense)	84,397			(5		)	2,939			—			—		87,331
	Net current period OCI - net of tax	(801,759		)	19,620			(27,637		)	295			220		(809,261		)
	Balance, end of period, net of tax	$	789,451		$	(101,751	)	$	41,762		$	(20,597	)	$	1,894	$	710,759
	____________
	-1	Included in these amounts are the impact of Shadow Adjustments. During the year ended December 31, 2013, the initial impact of $44.7 million was recorded. During the six months ended June 30, 2014, additional impacts of $474.5 million were recorded, resulting in a total cumulative impact of shadow adjustments on future policy benefit reserves of $519.2 million at June 30, 2014.
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 six months ended June 30, 2014 and 2013 are as follows:
	Gross Amount Reclassified From AOCI
	Details About AOCI Components	Three months ended June 30, 2014			Three months ended June 30, 2013			Six months ended June 30, 2014			Six months ended June 30, 2013			Affected Line Item in the Statement of Income
	(U.S. dollars in thousands)
	Unrealized gains and losses on investments:
		$	(107,470	)	$	(56,969	)	$	(132,384	)	$	(102,391	)	Net realized gains (losses) on investments sold
		33,133			1,561			35,409			5,289			OTTI on investments
		$	(74,337	)	$	(55,408	)	$	(96,975	)	$	(97,102	)	Total before tax
		1,477			(3,560		)	1,930			(3,286		)	Provision (benefit) for income tax
		$	(72,860	)	$	(58,968	)	$	(95,045	)	$	(100,388	)	Net of tax
	OTTI losses recognized in OCI:
		$	1,386		$	13,612		$	3,344		$	17,887		Net realized gains (losses) on investments sold
		254			828			1,705			1,738			OTTI on investments transferred to (from) OCI
		$	1,640		$	14,440		$	5,049		$	19,625		Total before tax
		(4		)	(2		)	(117		)	(5		)	Provision (benefit) for income tax
		$	1,636		$	14,438		$	4,932		$	19,620		Net of tax
	Gains and losses on cash flow hedges:
	Interest rate contracts	$	110		$	110		$	220		$	220		Interest Expense
		—			—			—			—			Provision (benefit) for income tax
		$	110		$	110		$	220		$	220		Net of tax
	Total reclassifications for the period, gross of tax	$	(72,587	)	$	(40,858	)	$	(91,706	)	$	(77,257	)
	Tax benefit (expense)	1,473			(3,562		)	1,813			(3,291		)
	Total reclassifications for the period, net of tax	$	(71,114	)	$	(44,420	)	$	(89,893	)	$	(80,548	)

Sale_of_Life_Reinsurance_Subsi2

Sale of Life Reinsurance Subsidiary (Details) (USD $)

3 Months Ended

6 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Dec. 31, 2013

1-May-14

30-May-14

30-May-14

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

XL Re Life (SAC) Ltd [Member]

XL Re Life (SAC) Ltd [Member]

Life Insurance Product Line [Member]

Life Funds Withheld Assets

Life Funds Withheld Assets

Life Funds Withheld Assets

Life Funds Withheld Assets

Life Funds Withheld Assets

XL Re Life (SAC) Ltd [Member]

XL Re Life (SAC) Ltd [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Sale of Subsidiary Stock, Percentage

'

'

'

'

'

100.00%

'

'

'

'

'

'

'

Disposal Group, Including Discontinued Operation, Consideration

'

'

'

'

'

$570,000,000

'

'

'

'

'

'

'

Quota Share Reinsurance Percentage

'

'

'

'

'

100.00%

'

'

'

'

'

'

'

Future policy benefit reserves

5,273,549,000

'

5,273,549,000

'

4,803,816,000

'

'

5,200,000,000

'

'

'

'

'

Estimated Future Policy Benefit Reserve Retention

'

'

'

'

'

'

400,000,000

'

'

'

'

'

'

Future policy benefit reserves recoverable

4,823,680,000

'

4,823,680,000

'

0

'

4,800,000,000

'

'

'

'

'

'

Estimated Assets Funds Withheld

'

'

'

'

'

'

5,700,000,000

'

'

'

'

'

'

Pro Forma Effect of Sale, After Tax Net Loss

'

'

'

'

'

621,300,000

'

'

'

'

'

'

'

Underwriting Profit Loss

135,074,000

39,792,000

232,305,000

168,174,000

'

'

'

'

'

'

'

'

0

Net investment income

232,773,000

232,546,000

465,962,000

479,014,000

'

'

'

'

19,165,000

0

19,165,000

0

19,165,000

Net realized gains (losses) on investments sold

'

'

'

'

'

'

'

'

624,000

0

624,000

0

624,000

OTTI on investments

'

'

'

'

'

'

'

'

-8,771,000

0

-8,771,000

0

-8,771,000

Other Income

-2,858,000

-791,000

-3,352,000

-1,055,000

'

'

'

'

'

'

'

'

-19,000

Net realized and unrealized gains (losses) on life retrocession embedded derivative

11,599,000

-5,105,000

13,409,000

2,780,000

'

'

'

'

-17,546,000

0

-17,546,000

0

-17,546,000

Net income (loss)

-275,579,000

275,878,000

15,897,000

662,410,000

'

'

'

'

'

'

'

'

-6,547,000

Change in net unrealized gains (losses) on investments, net of tax

'

'

'

'

'

'

'

'

'

0

12,297,000

0

12,297,000

Foreign currency translation adjustments, net of tax

-9,602,000

-23,718,000

-13,482,000

-27,637,000

'

'

'

'

'

'

'

'

-5,750,000

Other Comprehensive Income (Loss), Net of Tax

$260,373,000

($694,363,000)

$470,377,000

($809,261,000)

'

'

'

'

'

'

'

'

$0

Fair_Value_Measurements_Schedu

Fair Value Measurements - Schedule of assets and liabilities that were accounted for at fair value (Details) (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Assets	'		'
Fixed maturities, at fair value	$30,442,921		$27,500,136
Equity securities, at fair value	988,710		1,040,237
Short-term investments, at fair value	347,674		456,288
Total investments available for sale	31,779,305		28,996,661
U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		2,501,851
Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	'		11,125,830
RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		3,546,122
RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		398,768
CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,246,795
CDO	'		'
Assets	'		'
Fixed maturities, at fair value	'		717,313
Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,242,104
U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,845,812
Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		4,875,541
Recurring	'		'
Assets	'		'
Fixed maturities, at fair value	'		27,500,136
Equity securities, at fair value	988,710		1,040,237
Short-term investments, at fair value	347,674		456,288
Total investments available for sale	31,779,305		28,996,661
Cash equivalents	2,256,640		1,061,150
Other investments	928,743		870,582
Other assets	59,330		26,145
Total assets accounted for at fair value	35,147,057		30,954,538
Liabilities	'		'
Financial instruments sold, but not yet purchased	31,150		28,861
Other liabilities	68,400		104,143
Total liabilities accounted for at fair value	99,550		133,004
Recurring | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		2,501,851
Recurring | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	'		11,125,830
Recurring | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		3,546,122
Recurring | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		398,768
Recurring | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,246,795
Recurring | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	'		717,313
Recurring | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,242,104
Recurring | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,845,812
Recurring | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		4,875,541
Recurring | Quoted prices in active markets for identical assets (Level 1)	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Equity securities, at fair value	603,993	[1]	540,331	[1]
Short-term investments, at fair value	0	[2],[3]	0	[2],[3]
Total investments available for sale	603,993		540,331
Cash equivalents	1,792,096	[4]	834,514	[4]
Other investments	0		0	[5]
Other assets	0	[6]	0	[6]
Total assets accounted for at fair value	2,396,735		1,374,845
Liabilities	'		'
Financial instruments sold, but not yet purchased	1,854	[7]	0	[7]
Other liabilities	0	[6]	0	[6]
Total liabilities accounted for at fair value	1,854		0
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
Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	'		0	[2]
Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Quoted prices in active markets for identical assets (Level 1) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Quoted prices in active markets for identical assets (Level 1) | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Quoted prices in active markets for identical assets (Level 1) | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	'		0	[8]
Recurring | Quoted prices in active markets for identical assets (Level 1) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
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
Recurring | Significant other observable inputs (Level 2)	'		'
Assets	'		'
Fixed maturities, at fair value	'		26,723,418
Equity securities, at fair value	384,717	[1]	499,906	[1]
Short-term investments, at fair value	347,674	[2],[3]	454,273	[2],[3]
Total investments available for sale	30,417,999		27,677,597
Cash equivalents	464,544	[4]	226,636	[4]
Other investments	804,268	[5]	757,110	[5]
Other assets	48,117	[6]	27,487	[6]
Total assets accounted for at fair value	31,857,321		28,688,830
Liabilities	'		'
Financial instruments sold, but not yet purchased	29,296	[7]	28,861	[7]
Other liabilities	38,277	[6]	76,375	[6]
Total liabilities accounted for at fair value	67,573		105,236
Recurring | Significant other observable inputs (Level 2) | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		2,501,851
Recurring | Significant other observable inputs (Level 2) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	'		11,094,257	[2]
Recurring | Significant other observable inputs (Level 2) | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		3,535,649
Recurring | Significant other observable inputs (Level 2) | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		398,759
Recurring | Significant other observable inputs (Level 2) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,234,262
Recurring | Significant other observable inputs (Level 2) | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	'		7,060
Recurring | Significant other observable inputs (Level 2) | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,230,227	[8]
Recurring | Significant other observable inputs (Level 2) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	'		1,845,812
Recurring | Significant other observable inputs (Level 2) | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		4,875,541
Recurring | Significant other unobservable inputs (Level 3)	'		'
Assets	'		'
Fixed maturities, at fair value	'		776,718
Equity securities, at fair value	0	[1]	0	[1]
Short-term investments, at fair value	0	[2],[3]	2,015	[2],[3]
Total investments available for sale	757,313		778,733
Cash equivalents	0	[4]	0	[4]
Other investments	124,475	[5]	113,472	[5]
Other assets	12,453	[6]	0	[6]
Total assets accounted for at fair value	894,241		892,205
Liabilities	'		'
Financial instruments sold, but not yet purchased	0	[7]	0	[7]
Other liabilities	31,363	[6]	29,110	[6]
Total liabilities accounted for at fair value	31,363		29,110
Recurring | Significant other unobservable inputs (Level 3) | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Significant other unobservable inputs (Level 3) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	'		31,573	[2]
Recurring | Significant other unobservable inputs (Level 3) | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		10,473
Recurring | Significant other unobservable inputs (Level 3) | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		9
Recurring | Significant other unobservable inputs (Level 3) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	'		12,533
Recurring | Significant other unobservable inputs (Level 3) | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	'		710,253
Recurring | Significant other unobservable inputs (Level 3) | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	'		11,877	[8]
Recurring | Significant other unobservable inputs (Level 3) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
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
Recurring | Collateral and counterparty netting	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Equity securities, at fair value	0	[1]	0	[1]
Short-term investments, at fair value	0	[2],[3]	0	[2],[3]
Total investments available for sale	0		0
Cash equivalents	0	[4]	0	[4]
Other investments	0	[5]	0	[5]
Other assets	-1,240	[6]	-1,342	[6]
Total assets accounted for at fair value	-1,240		-1,342
Liabilities	'		'
Financial instruments sold, but not yet purchased	0	[7]	0	[7]
Other liabilities	-1,240	[6]	-1,342	[6]
Total liabilities accounted for at fair value	-1,240		-1,342
Recurring | Collateral and counterparty netting | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Collateral and counterparty netting | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	'		0	[2]
Recurring | Collateral and counterparty netting | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Collateral and counterparty netting | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Collateral and counterparty netting | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Collateral and counterparty netting | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Collateral and counterparty netting | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	'		0	[8]
Recurring | Collateral and counterparty netting | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Recurring | Collateral and counterparty netting | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	'		0
Excluding Life Funds Withheld Assets	'		'
Assets	'		'
Fixed maturities, at fair value	24,998,550		'
Total investments available for sale	26,334,934		'
Excluding Life Funds Withheld Assets | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	2,084,294		'
Excluding Life Funds Withheld Assets | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	9,727,624		'
Excluding Life Funds Withheld Assets | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	3,303,046		'
Excluding Life Funds Withheld Assets | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	415,503		'
Excluding Life Funds Withheld Assets | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	1,124,287		'
Excluding Life Funds Withheld Assets | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	738,073		'
Excluding Life Funds Withheld Assets | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	1,310,272		'
Excluding Life Funds Withheld Assets | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	1,939,590		'
Excluding Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	4,355,861		'
Excluding Life Funds Withheld Assets | Recurring	'		'
Assets	'		'
Fixed maturities, at fair value	24,998,550		'
Total investments available for sale	26,334,934		'
Excluding Life Funds Withheld Assets | Recurring | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	2,084,294		'
Excluding Life Funds Withheld Assets | Recurring | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	9,727,624		'
Excluding Life Funds Withheld Assets | Recurring | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	3,303,046		'
Excluding Life Funds Withheld Assets | Recurring | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	415,503		'
Excluding Life Funds Withheld Assets | Recurring | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	1,124,287		'
Excluding Life Funds Withheld Assets | Recurring | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	738,073		'
Excluding Life Funds Withheld Assets | Recurring | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	1,310,272		'
Excluding Life Funds Withheld Assets | Recurring | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	1,939,590		'
Excluding Life Funds Withheld Assets | Recurring | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	4,355,861		'
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1)	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Total investments available for sale	603,993		'
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		'
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	0	[2]	'
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		'
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		'
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	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	0	[8]	'
Excluding Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	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		'
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2)	'		'
Assets	'		'
Fixed maturities, at fair value	24,241,237		'
Total investments available for sale	24,973,628		'
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	2,084,294		'
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	9,723,691	[2]	'
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	3,296,150		'
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	415,492		'
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	1,122,342		'
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	5,249		'
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	1,298,568	[8]	'
Excluding Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	1,939,590		'
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	4,355,861		'
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3)	'		'
Assets	'		'
Fixed maturities, at fair value	757,313		'
Total investments available for sale	757,313		'
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		'
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	3,933	[2]	'
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	6,896		'
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	11		'
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	1,945		'
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	732,824		'
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	11,704	[8]	'
Excluding Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	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		'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Total investments available for sale	0		'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	0	[2]	'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	0	[8]	'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Excluding Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets	'		'
Assets	'		'
Fixed maturities, at fair value	5,444,371		0
Life Funds Withheld Assets | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	18,225		'
Life Funds Withheld Assets | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	3,017,446		'
Life Funds Withheld Assets | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	4,023		'
Life Funds Withheld Assets | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	88,104		'
Life Funds Withheld Assets | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	216,844		'
Life Funds Withheld Assets | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	293,617		'
Life Funds Withheld Assets | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	1,806,112		'
Life Funds Withheld Assets | Recurring	'		'
Assets	'		'
Fixed maturities, at fair value	5,444,371		'
Cash equivalents	123,039		'
Life Funds Withheld Assets | Recurring | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	18,225		'
Life Funds Withheld Assets | Recurring | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	3,017,446		'
Life Funds Withheld Assets | Recurring | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	4,023		'
Life Funds Withheld Assets | Recurring | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	88,104		'
Life Funds Withheld Assets | Recurring | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	216,844		'
Life Funds Withheld Assets | Recurring | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	293,617		'
Life Funds Withheld Assets | Recurring | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	1,806,112		'
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1)	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Cash equivalents	646	[4]	'
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		'
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	0	[2]	'
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	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		'
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | CDO	'		'
Assets	'		'
Fixed maturities, 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	[8]	'
Life Funds Withheld Assets | Recurring | Quoted prices in active markets for identical assets (Level 1) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, 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		'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2)	'		'
Assets	'		'
Fixed maturities, at fair value	5,444,371		'
Cash equivalents	122,393	[4]	'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	18,225		'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	3,017,446	[2]	'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	4,023		'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	88,104		'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	216,844		'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	293,617	[8]	'
Life Funds Withheld Assets | Recurring | Significant other observable inputs (Level 2) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
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	1,806,112		'
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3)	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Cash equivalents	0	[4]	'
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		'
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	0	[2]	'
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | CDO	'		'
Assets	'		'
Fixed maturities, 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	[8]	'
Life Funds Withheld Assets | Recurring | Significant other unobservable inputs (Level 3) | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, 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		'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Cash equivalents	0	[4]	'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | U.S. Government and Government - Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | Corporate	'		'
Assets	'		'
Fixed maturities, at fair value	0	[2]	'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | RMBS - Agency	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | RMBS - Non-Agency	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | CMBS	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | CDO	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | Other asset-backed securities	'		'
Assets	'		'
Fixed maturities, at fair value	0	[8]	'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | U.S. States and political subdivisions of the States	'		'
Assets	'		'
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Recurring | Collateral and counterparty netting | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'
Assets	'		'
Fixed maturities, at fair value	$0		'
[1]	Included within Equity securities are investments in fixed income funds with a fair value of $92.1 million and $87.4 million at JuneB 30, 2014 and DecemberB 31, 2013, respectively.
[2]	Included within Corporate 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 $155.9 million and $154.6 million and an amortized cost of $143.6 million and $147.7 million at JuneB 30, 2014 and DecemberB 31, 2013, 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.
[3]	Short-term investments consist primarily of Corporate securities and U.S. and Non-U.S. Government and Government-Related/Supported securities.
[4]	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.
[5]	The Other investments balance excludes certain structured transactions including certain investments in project finance transactions, 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 $275.8 million at JuneB 30, 2014 and $294.0 million at DecemberB 31, 2013, are carried at amortized cost. For further information, see Item 8, Note 7, bOther Investments,b to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended DecemberB 31, 2013.
[6]	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, bDerivative Instruments,b to the Unaudited Consolidated Financial Statements.
[7]	Financial instruments sold, but not yet purchased, represent bshort salesb and are included within bPayable for investments purchasedb on the balance sheets.
[8]	The Company invests in covered bonds (bCovered Bondsb). Covered Bonds are senior secured debt instruments issued by financial institutions and backed by over-collateralized pools of public sector or mortgage loans. At JuneB 30, 2014 and DecemberB 31, 2013, Covered Bonds with a fair value of $763.6 million and $553.1 million, respectively, are included within Other asset-backed securities.

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional information about assets and liabilities measured at fair value on a recurring basis (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Corporate	'	'	'	'
Level 3 assets	'	'	'	'
Balance, beginning of period	$4,382	$40,815	$31,573	$30,098
Realized gains (losses)	35	-69	155	-71
Movement in unrealized gains (losses)	-93	426	-96	630
Purchases and issuances	8	0	1,443	10,621
Sales	0	0	0	0
Settlements	-399	-7,139	-5,513	-7,245
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	-1,860	-23,629	-1,860
Fixed maturities to short-term investments classification change	0	0	0	0
Balance, end of period	3,933	32,173	3,933	32,173
Movement in total gains (losses) above relating to instruments still held at the reporting date	-58	424	90	627
RMBS - Agency	'	'	'	'
Level 3 assets	'	'	'	'
Balance, beginning of period	8,928	19,107	10,473	32,005
Realized gains (losses)	6	-2	6	11
Movement in unrealized gains (losses)	-13	-19	-13	-37
Purchases and issuances	0	0	0	0
Sales	0	0	0	-535
Settlements	-2,025	-872	-2,598	-1,765
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	-972	-11,465
Fixed maturities to short-term investments classification change	0	0	0	0
Balance, end of period	6,896	18,214	6,896	18,214
Movement in total gains (losses) above relating to instruments still held at the reporting date	-6	-22	-6	-40
RMBS - Non-Agency	'	'	'	'
Level 3 assets	'	'	'	'
Balance, beginning of period	11	103	9	116
Realized gains (losses)	0	0	0	0
Movement in unrealized gains (losses)	0	0	2	0
Purchases and issuances	0	3,326	0	3,326
Sales	0	0	0	0
Settlements	0	-18	0	-31
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	11	3,411	11	3,411
Movement in total gains (losses) above relating to instruments still held at the reporting date	0	-1	2	-1
CMBS	'	'	'	'
Level 3 assets	'	'	'	'
Balance, beginning of period	5,926	25,012	12,533	25,347
Realized gains (losses)	2	0	3	0
Movement in unrealized gains (losses)	-1	-19	-3	-18
Purchases and issuances	1,376	0	1,376	0
Sales	0	0	0	0
Settlements	-5,358	-570	-11,964	-906
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	1,945	24,423	1,945	24,423
Movement in total gains (losses) above relating to instruments still held at the reporting date	0	-19	0	-18
CDO	'	'	'	'
Level 3 assets	'	'	'	'
Balance, beginning of period	718,827	702,904	710,253	701,736
Realized gains (losses)	875	-55	2,456	301
Movement in unrealized gains (losses)	8,331	14,491	12,013	35,746
Purchases and issuances	75,201	5,362	103,015	5,362
Sales	-30,892	0	-40,824	0
Settlements	-39,518	-16,689	-54,089	-37,132
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	732,824	706,013	732,824	706,013
Movement in total gains (losses) above relating to instruments still held at the reporting date	8,247	13,804	13,216	34,278
Other asset-backed securities	'	'	'	'
Level 3 assets	'	'	'	'
Balance, beginning of period	10,673	35,887	11,877	18,128
Realized gains (losses)	-5	-13	-20	38
Movement in unrealized gains (losses)	144	-512	206	963
Purchases and issuances	3,000	0	3,000	21,686
Sales	0	0	0	0
Settlements	-2,108	-1,317	-3,359	-6,770
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	-6,506	0	-6,506
Fixed maturities to short-term investments classification change	0	0	0	0
Balance, end of period	11,704	27,539	11,704	27,539
Movement in total gains (losses) above relating to instruments still held at the reporting date	140	-525	186	-516
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	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	2,017	2,015	0
Realized gains (losses)	0	-10	0	-10
Movement in unrealized gains (losses)	0	-8	-15	-8
Purchases and issuances	0	0	0	2,017
Sales	0	0	0	0
Settlements	0	0	-2,000	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	0	1,999	0	1,999
Movement in total gains (losses) above relating to instruments still held at the reporting date	0	-18	0	-18
Other investments	'	'	'	'
Level 3 assets	'	'	'	'
Balance, beginning of period	116,418	113,322	113,472	115,272
Realized gains (losses)	5,127	2,872	8,691	5,787
Movement in unrealized gains (losses)	-1,779	932	-282	-970
Purchases and issuances	9,997	1,002	21,086	2,907
Sales	0	0	0	0
Settlements	-5,288	-14,284	-18,492	-19,152
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	124,475	103,844	124,475	103,844
Movement in total gains (losses) above relating to instruments still held at the reporting date	3,348	3,812	8,409	4,808
Derivative contracts - net	'	'	'	'
Level 3 liabilities	'	'	'	'
Balance, beginning of period	-32,496	-32,550	-29,110	-36,247
Realized gains (losses)	0	0	0	0
Movement in unrealized gains (losses)	13,586	3,176	10,200	6,873
Purchases and issuances	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
Balance, end of period	-18,910	-29,374	-18,910	-29,374
Movement in total gains (losses) above relating to instruments still held at the reporting date	$13,586	$3,176	$10,200	$6,873

Fair_Value_Measurements_Financ

Fair Value Measurements - Financial instruments not carried at fair value (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fixed maturities, held to maturity	$0	$2,858,695
Other investments - structured transactions	275,821	294,048
Deposit liabilities	1,288,376	1,509,243
Notes payable and debt	2,262,452	2,263,203
Fair value of held to maturity securities	0	3,131,235
Carrying Value	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fixed maturities, held to maturity	0	2,858,695
Other investments - structured transactions	275,821	294,048
Financial Assets	275,821	3,152,743
Deposit liabilities	1,288,376	1,509,243
Notes payable and debt	2,262,452	2,263,203
Financial Liabilities	3,550,828	3,772,446
Fair Value	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Fixed maturities, held to maturity	0	3,131,235
Other investments - structured transactions	299,661	296,799
Financial Assets	299,661	3,428,034
Deposit liabilities	1,520,108	1,718,394
Notes payable and debt	2,511,270	2,429,412
Financial Liabilities	$4,031,378	$4,147,806

Fair_Value_Measurements_Narrat

Fair Value Measurements - Narrative (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities, at fair value	$30,442,921	$27,500,136
Amortized cost of fixed maturities	29,065,531	27,111,874
Equity securities, at fair value	988,710	1,040,237
Other investments - structured transactions	275,821	294,048
Spread on U.S. treasury for discounting deposit liabilities	0.46%	0.57%
Corporate	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities, at fair value	'	11,125,830
Amortized cost of fixed maturities	'	10,802,332
Medium term notes	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities, at fair value	155,900	154,600
Amortized cost of fixed maturities	143,600	147,700
Other asset-backed securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities, at fair value	'	1,242,104
Amortized cost of fixed maturities	'	1,210,384
Covered bonds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities, at fair value	763,600	553,100
Amortized cost of fixed maturities	737,000	526,400
Fixed income funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities, at fair value	$92,100	$87,400

Segment_Information_Statement_

Segment Information - Statement of earnings by segment (Details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Segment Reporting Information [Line Items]	'		'		'		'
Gross premiums written	$2,198,239		$2,025,472		$4,711,175		$4,503,358
Net premiums written	1,491,844		1,533,868		3,487,695		3,641,522
Net premiums earned	1,496,594		1,562,393		2,985,433		3,092,084
Net losses and loss expenses	913,179		1,054,373		1,858,271		2,008,410
Acquisition costs	184,619		231,886		384,033		452,145
Operating expenses	263,722		236,342		510,824		463,355
Underwriting profit (loss)	135,074		39,792		232,305		168,174
Net investment income	'		214,410		'		443,137
Net results from structured products	34,885		6,053		42,838		11,229
Net fee income and other	-2,858		-791		-3,352		-1,055
Loss on sale of life reinsurance subsidiary	666,423		0		666,423		0
Net realized gains (losses) on investments	72,697		40,968		91,926		77,477
Net realized and unrealized gains (losses) on derivative instruments	11,599		-5,105		13,409		2,780
Net income (loss) from investment fund affiliates and operating affiliates	45,421		79,368		125,009		142,587
Exchange (gains) losses	21,141		-11,331		31,582		-44,766
Corporate operating expenses	56,495		55,155		107,833		102,077
Contribution from P&C and Corporate and Other	-248,949		330,871		109,008		787,018
Interest expense	32,284		26,121		64,444		52,257
Non-controlling interests	3,682		3,180		39,441		38,922
Income tax	-5,654		28,872		28,667		72,351
Net income (loss) attributable to ordinary shareholders	-279,261		272,698		-23,544		623,488
Corporate and Other [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Gross premiums written	86,710	[1]	81,302	[1]	171,007	[1]	154,272	[1]
Net premiums written	58,518	[1]	73,896	[1]	134,829	[1]	139,341	[1]
Net premiums earned	58,518	[1]	73,896	[1]	134,829	[1]	139,341	[1]
Net losses and loss expenses	85,299	[1]	116,767	[1]	198,886	[1]	227,720	[1]
Acquisition costs	3,882	[1]	7,255	[1]	11,061	[1]	11,358	[1]
Operating expenses	2,209	[1],[2]	2,206	[1],[2]	5,397	[1],[2]	4,801	[1],[2]
Underwriting profit (loss)	-32,872	[1]	-52,332	[1]	-80,515	[1]	-104,538	[1]
Net investment income	'		70,592	[1]	'		142,280	[1]
Net results from structured products	0	[1],[3]	0	[1],[4]	0	[1],[5]	0	[1],[6]
Net fee income and other	45	[1],[7]	44	[1],[7]	90	[1],[7]	1,087	[1],[7]
Loss on sale of life reinsurance subsidiary	666,423	[1]	'		666,423	[1]	'
Net realized and unrealized gains (losses) on derivative instruments	11,599	[1]	-5,105	[1]	13,409	[1]	2,780	[1]
Net income (loss) from investment fund affiliates and operating affiliates	45,421	[1],[8]	79,368	[1]	125,009	[1]	142,587	[1]
Exchange (gains) losses	21,141	[1]	-11,331	[1]	31,582	[1]	-44,766	[1]
Corporate operating expenses	56,495	[1]	55,155	[1]	107,833	[1]	102,077	[1]
Contribution from P&C and Corporate and Other	-671,937	[1]	60,342	[1]	-627,461	[1]	129,415	[1]
Interest expense	32,284	[1],[9]	26,121	[1]	64,444	[1]	52,257	[1]
Non-controlling interests	3,682	[1]	3,180	[1]	39,441	[1]	38,922	[1]
Income tax	-5,654	[1]	28,872	[1]	28,667	[1]	72,351	[1]
Total P&C	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Gross premiums written	2,111,529		1,944,170		4,540,168		4,349,086
Net premiums written	1,433,326		1,459,972		3,352,866		3,502,181
Net premiums earned	1,438,076		1,488,497		2,850,604		2,952,743
Net losses and loss expenses	827,880		937,606		1,659,385		1,780,690
Acquisition costs	180,737		224,631		372,972		440,787
Operating expenses	261,513	[2]	234,136	[2]	505,427	[2]	458,554	[2]
Underwriting profit (loss)	167,946		92,124		312,820		272,712
Net investment income	'		143,818		'		300,857
Net results from structured products	34,885	[3]	6,053	[4]	42,838	[5]	11,229	[6]
Net fee income and other	-2,903	[7]	-835	[7]	-3,442	[7]	-2,142	[7]
Contribution from P&C and Corporate and Other	422,988		270,529		736,469		657,603
Ratios - P&C operations	'		'		'		'
Loss and loss expense ratio	57.60%	[10]	63.00%	[10]	58.20%	[10]	60.30%	[10]
Underwriting expense ratio	30.70%	[10]	30.80%	[10]	30.80%	[10]	30.50%	[10]
Combined ratio	88.30%	[10]	93.80%	[10]	89.00%	[10]	90.80%	[10]
Insurance Segment	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Gross premiums written	1,618,405		1,472,388		3,189,331		2,970,175
Net premiums written	996,880		1,049,163		2,124,247		2,238,351
Net premiums earned	1,003,990		1,058,542		1,996,430		2,097,634
Net losses and loss expenses	627,627		721,323		1,266,820		1,371,840
Acquisition costs	99,863		138,032		204,863		268,654
Operating expenses	213,931	[2]	194,514	[2]	416,984	[2]	378,511	[2]
Underwriting profit (loss)	62,569		4,673		107,763		78,629
Net results from structured products	31,645	[3]	3,532	[4]	36,535	[5]	7,717	[6]
Net fee income and other	-3,567	[7]	-1,355	[7]	-4,779	[7]	-3,294	[7]
Ratios - P&C operations	'		'		'		'
Loss and loss expense ratio	62.50%	[10]	68.10%	[10]	63.50%	[10]	65.40%	[10]
Underwriting expense ratio	31.30%	[10]	31.50%	[10]	31.10%	[10]	30.90%	[10]
Combined ratio	93.80%	[10]	99.60%	[10]	94.60%	[10]	96.30%	[10]
Reinsurance Segment	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Gross premiums written	493,124		471,782		1,350,837		1,378,911
Net premiums written	436,446		410,809		1,228,619		1,263,830
Net premiums earned	434,086		429,955		854,174		855,109
Net losses and loss expenses	200,253		216,283		392,565		408,850
Acquisition costs	80,874		86,599		168,109		172,133
Operating expenses	47,582	[2]	39,622	[2]	88,443	[2]	80,043	[2]
Underwriting profit (loss)	105,377		87,451		205,057		194,083
Net results from structured products	3,240	[3]	2,521	[4]	6,303	[5]	3,512	[6]
Net fee income and other	664	[7]	520	[7]	1,337	[7]	1,152	[7]
Ratios - P&C operations	'		'		'		'
Loss and loss expense ratio	46.10%	[10]	50.30%	[10]	46.00%	[10]	47.80%	[10]
Underwriting expense ratio	29.60%	[10]	29.40%	[10]	30.00%	[10]	29.50%	[10]
Combined ratio	75.70%	[10]	79.70%	[10]	76.00%	[10]	77.30%	[10]
Excluding Life Funds Withheld Assets	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net investment income	196,673		'		411,092		'
Net realized gains (losses) on investments	80,844		40,968		100,073		77,477
Excluding Life Funds Withheld Assets | Corporate and Other [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net investment income	52,118	[1]	'		123,010	[1]	'
Net realized gains (losses) on investments	2,339	[1]	11,599	[1]	3,902	[1]	2,530	[1]
Excluding Life Funds Withheld Assets | Total P&C	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net investment income	144,555		'		288,082		'
Net realized gains (losses) on investments	78,505		29,369		96,171		74,947
Life Funds Withheld Assets	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net investment income	19,165		'		19,165		'
Net realized gains (losses) on investments	-8,147		0		-8,147		0
Net realized and unrealized gains (losses) on derivative instruments	-17,546		0		-17,546		0
Life Funds Withheld Assets | Corporate and Other [Member]	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net investment income	19,165	[1]	'		19,165	[1]	'
Net realized gains (losses) on investments	-8,147	[1]	0	[1]	-8,147	[1]	0	[1]
Net realized and unrealized gains (losses) on derivative instruments	($17,546)	[1]	'		($17,546)	[1]	'
[1]	Corporate and Other includes the Company's run-off life operations.
[2]	Operating expenses exclude Corporate operating expenses, shown separately.
[3]	The net results from structured products include net investment income and interest expense (credit) of $16.9 million and $(18.2) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
[4]	The net results from structured products include net investment income and interest expense of $18.1 million and $12.1 million, respectively.
[5]	The net results from structured products include net investment income and net interest expense (credit) of $35.7 million and $(7.4) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
[6]	The net results from structured products include net investment income and interest expense of $35.9 million and $24.6 million, respectively.
[7]	Net fee income and other includes operating expenses from the Company's loss prevention consulting services business.
[8]	The Company records the income related to the alternative funds 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]	Ratios are based on net premiums earned from P&C operations.

Segment_Information_Net_Premiu

Segment Information - Net Premiums Earned by Line of Business (Details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Net premiums earned by line of business:	'		'		'		'
Life Operations	$58,518		$73,896		$134,829		$139,341
Total	1,496,594		1,562,393		2,985,433		3,092,084
Total P&C	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	1,438,076		1,488,497		2,850,604		2,952,743
Total	1,438,076		1,488,497		2,850,604		2,952,743
Insurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	1,003,990		1,058,542		1,996,430		2,097,634
Total	1,003,990		1,058,542		1,996,430		2,097,634
Reinsurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	434,086		429,955		854,174		855,109
Total	434,086		429,955		854,174		855,109
Corporate and Other [Member]	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
Life Operations	58,518		73,896		134,829		139,341
Total	58,518	[1]	73,896	[1]	134,829	[1]	139,341	[1]
Professional | Total P&C	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	311,748		400,790		637,279		797,064
Professional | Insurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	267,509		349,812		542,936		700,650
Professional | Reinsurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	44,239		50,978		94,343		96,414
Casualty | Total P&C	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	441,919		414,981		862,644		819,380
Casualty | Insurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	358,990		338,437		702,994		665,855
Casualty | Reinsurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	82,929		76,544		159,650		153,525
Property catastrophe | Total P&C	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	112,562		129,361		220,999		243,003
Property catastrophe | Insurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	0		0		0		0
Property catastrophe | Reinsurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	112,562		129,361		220,999		243,003
Property | Total P&C	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	285,211		267,590		560,183		533,309
Property | Insurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	142,874		135,089		282,607		259,539
Property | Reinsurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	142,337		132,501		277,576		273,770
Marine, energy, aviation and satellite | Total P&C	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	21,065		24,588		44,579		52,428
Marine, energy, aviation and satellite | Insurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	0		0		0		0
Marine, energy, aviation and satellite | Reinsurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	21,065		24,588		44,579		52,428
Specialty | Total P&C	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	179,948		181,131		356,857		364,096
Specialty | Insurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	179,948		181,131		356,857		364,096
Specialty | Reinsurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	0		0		0		0
Other | Total P&C	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	85,623	[2]	70,056	[2]	168,063	[2]	143,463	[2]
Other | Insurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	54,669	[2]	54,073	[2]	111,036	[2]	107,494	[2]
Other | Reinsurance Segment	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
P&C Operations	30,954	[2]	15,983	[2]	57,027	[2]	35,969	[2]
Annuity	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
Life Operations	21,565		30,087		53,362		59,771
Annuity | Corporate and Other [Member]	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
Life Operations	21,565		30,087		53,362		59,771
Other life	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
Life Operations	36,953		43,809		81,467		79,570
Other life | Corporate and Other [Member]	'		'		'		'
Net premiums earned by line of business:	'		'		'		'
Life Operations	$36,953		$43,809		$81,467		$79,570
[1]	Corporate and Other includes the Company's run-off life operations.
[2]	Other within the Insurance segment includes: excess and surplus, programs, surety, structured indemnity and certain other discontinued lines. Other within the Reinsurance segment includes: whole account contracts, accident and health and other lines.

Segment_Information_Narrative_

Segment Information - Narrative (Details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
					segments
Segment Reporting Information [Line Items]	'		'		'		'
Net results from structured products	$34,885		$6,053		$42,838		$11,229
Number of segments	'		'		2		'
Total P&C	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net results from structured products	34,885	[1]	6,053	[2]	42,838	[3]	11,229	[4]
Net investment income | Total P&C	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net results from structured products	16,900		18,100		35,700		35,900
Interest expense | Total P&C	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net results from structured products	18,200		-12,100		7,400		-24,600
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		'
Structured Indemnity [Member] | Interest expense | Total P&C	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Net results from structured products	$28,700		'		'		'
[1]	The net results from structured products include net investment income and interest expense (credit) of $16.9 million and $(18.2) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
[2]	The net results from structured products include net investment income and interest expense of $18.1 million and $12.1 million, respectively.
[3]	The net results from structured products include net investment income and net interest expense (credit) of $35.7 million and $(7.4) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
[4]	The net results from structured products include net investment income and interest expense of $35.9 million and $24.6 million, respectively.

Investments_Cost_amortized_cos

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 $)	Jun. 30, 2014		1-May-14	Dec. 31, 2013
In Thousands, unless otherwise specified
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	$29,065,531		'	$27,111,874
Gross unrealized gains on Fixed maturities	'		'	807,684
Gross unrealized losses on Fixed maturities	'		'	-419,422
Fixed maturities, at fair value	30,442,921		'	27,500,136
Gross Unrealized Losses Non-credit related OTTI	-81,834		'	-86,882	[1]
Short-term investments, amortized cost	347,473		'	455,470
Short-term investments, gross unrealized gains	972	[2]	'	962	[3]
Short-term investments, gross unrealized losses	-771	[2]	'	-144	[3]
Short-term investments, at fair value	347,674		'	456,288
Cost of equity securities	839,716		'	903,201
Equity securities, gross unrealized gains	151,618	[4]	'	154,506	[5]
Equity securities, gross unrealized losses	-2,624	[4]	'	-17,470	[5]
Equity securities, at fair value	988,710		'	1,040,237
Available for sale securities, Cost or amortized cost	30,252,720		'	28,470,545
Available for sale securities, Gross unrealized gains	1,695,830		'	963,152
Available for sale securities, Gross unrealized losses	-169,245		'	-437,036
Total investments available for sale	31,779,305		'	28,996,661
Fixed maturities - HTM	'		'	'
Fixed maturities, held to maturity	0		'	2,858,695
Fixed maturites held to maturity, gross unrealized gains	0		424,861	274,150
Fixed maturites held to maturity, gross unrealized losses	0		0	-1,610
Fair value of held to maturity securities	0		'	3,131,235
U.S. Government and Government - Related/Supported	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	2,484,193
Gross unrealized gains on Fixed maturities	'		'	51,701	[3]
Gross unrealized losses on Fixed maturities	'		'	-34,043	[3]
Fixed maturities, at fair value	'		'	2,501,851
Gross Unrealized Losses Non-credit related OTTI	'		'	0	[1],[3]
Fixed maturities - HTM	'		'	'
Fixed maturities, held to maturity	0		'	10,993
Fixed maturites held to maturity, gross unrealized gains	'		'	629	[3]
Fixed maturites held to maturity, gross unrealized losses	'		'	0	[3]
Fair value of held to maturity securities	'		'	11,622
Corporate	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	10,802,332
Gross unrealized gains on Fixed maturities	'		'	433,097	[6],[7]
Gross unrealized losses on Fixed maturities	'		'	-109,599	[6],[7]
Fixed maturities, at fair value	'		'	11,125,830
Gross Unrealized Losses Non-credit related OTTI	'		'	-4,758	[1],[6],[7]
Fixed maturities - HTM	'		'	'
Fixed maturities, held to maturity	'		'	1,386,863
Fixed maturites held to maturity, gross unrealized gains	'		'	113,179
Fixed maturites held to maturity, gross unrealized losses	'		'	-968
Fair value of held to maturity securities	'		'	1,499,074
RMBS - Agency	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	3,540,101
Gross unrealized gains on Fixed maturities	'		'	68,098
Gross unrealized losses on Fixed maturities	'		'	-62,077
Fixed maturities, at fair value	'		'	3,546,122
Gross Unrealized Losses Non-credit related OTTI	'		'	0	[1]
RMBS - Non-Agency	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	396,798
Gross unrealized gains on Fixed maturities	'		'	33,096
Gross unrealized losses on Fixed maturities	'		'	-31,126
Fixed maturities, at fair value	'		'	398,768
Gross Unrealized Losses Non-credit related OTTI	'		'	-74,528	[1]
Fixed maturities - HTM	'		'	'
Fixed maturities, held to maturity	0		'	66,987
Fixed maturites held to maturity, gross unrealized gains	'		'	4,985
Fixed maturites held to maturity, gross unrealized losses	'		'	0
Fair value of held to maturity securities	'		'	71,972
CMBS	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	1,223,313
Gross unrealized gains on Fixed maturities	'		'	39,255
Gross unrealized losses on Fixed maturities	'		'	-15,773
Fixed maturities, at fair value	'		'	1,246,795
Gross Unrealized Losses Non-credit related OTTI	'		'	-2,753	[1]
Fixed maturities - HTM	'		'	'
Fixed maturities, held to maturity	0		'	144,924
Fixed maturites held to maturity, gross unrealized gains	'		'	11,864
Fixed maturites held to maturity, gross unrealized losses	'		'	0
Fair value of held to maturity securities	'		'	156,788
CDO	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	754,414
Gross unrealized gains on Fixed maturities	'		'	5,833
Gross unrealized losses on Fixed maturities	'		'	-42,934
Fixed maturities, at fair value	'		'	717,313
Gross Unrealized Losses Non-credit related OTTI	'		'	-2,036	[1]
Other asset-backed securities	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	1,210,384
Gross unrealized gains on Fixed maturities	'		'	40,560	[8]
Gross unrealized losses on Fixed maturities	'		'	-8,840	[8]
Fixed maturities, at fair value	'		'	1,242,104
Gross Unrealized Losses Non-credit related OTTI	'		'	-2,807	[1],[8]
Fixed maturities - HTM	'		'	'
Fixed maturities, held to maturity	0		'	106,540
Fixed maturites held to maturity, gross unrealized gains	'		'	6,908	[8]
Fixed maturites held to maturity, gross unrealized losses	'		'	0	[8]
Fair value of held to maturity securities	'		'	113,448
U.S. States and political subdivisions of the States	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	1,821,499
Gross unrealized gains on Fixed maturities	'		'	55,083
Gross unrealized losses on Fixed maturities	'		'	-30,770
Fixed maturities, at fair value	'		'	1,845,812
Gross Unrealized Losses Non-credit related OTTI	'		'	0	[1]
Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	'		'	4,878,840
Gross unrealized gains on Fixed maturities	'		'	80,961	[3]
Gross unrealized losses on Fixed maturities	'		'	-84,260	[3]
Fixed maturities, at fair value	'		'	4,875,541
Gross Unrealized Losses Non-credit related OTTI	'		'	0	[1],[3]
Fixed maturities - HTM	'		'	'
Fixed maturities, held to maturity	0		'	1,142,388
Fixed maturites held to maturity, gross unrealized gains	'		'	136,585	[3]
Fixed maturites held to maturity, gross unrealized losses	'		'	-642	[3]
Fair value of held to maturity securities	'		'	1,278,331
Excluding Life Funds Withheld Assets	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	24,226,460		'	'
Gross unrealized gains on Fixed maturities	937,940		'	'
Gross unrealized losses on Fixed maturities	-165,850		'	'
Fixed maturities, at fair value	24,998,550		'	'
Gross Unrealized Losses Non-credit related OTTI	-81,834	[1]	'	'
Available for sale securities, Cost or amortized cost	25,413,649		'	'
Available for sale securities, Gross unrealized gains	1,090,530		'	'
Available for sale securities, Gross unrealized losses	-169,245		'	'
Total investments available for sale	26,334,934		'	'
Excluding Life Funds Withheld Assets | U.S. Government and Government - Related/Supported	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	2,033,152		'	'
Gross unrealized gains on Fixed maturities	60,408	[2]	'	'
Gross unrealized losses on Fixed maturities	-9,266	[2]	'	'
Fixed maturities, at fair value	2,084,294		'	'
Gross Unrealized Losses Non-credit related OTTI	0	[1],[2]	'	'
Excluding Life Funds Withheld Assets | Corporate	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	9,345,654		'	'
Gross unrealized gains on Fixed maturities	425,093	[10],[9]	'	'
Gross unrealized losses on Fixed maturities	-43,123	[10],[9]	'	'
Fixed maturities, at fair value	9,727,624		'	'
Gross Unrealized Losses Non-credit related OTTI	-4,758	[1],[10],[9]	'	'
Excluding Life Funds Withheld Assets | RMBS - Agency	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	3,218,551		'	'
Gross unrealized gains on Fixed maturities	104,874		'	'
Gross unrealized losses on Fixed maturities	-20,379		'	'
Fixed maturities, at fair value	3,303,046		'	'
Gross Unrealized Losses Non-credit related OTTI	0	[1]	'	'
Excluding Life Funds Withheld Assets | RMBS - Non-Agency	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	395,629		'	'
Gross unrealized gains on Fixed maturities	41,054		'	'
Gross unrealized losses on Fixed maturities	-21,180		'	'
Fixed maturities, at fair value	415,503		'	'
Gross Unrealized Losses Non-credit related OTTI	-70,645	[1]	'	'
Excluding Life Funds Withheld Assets | CMBS	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	1,098,149		'	'
Gross unrealized gains on Fixed maturities	33,562		'	'
Gross unrealized losses on Fixed maturities	-7,424		'	'
Fixed maturities, at fair value	1,124,287		'	'
Gross Unrealized Losses Non-credit related OTTI	-2,561	[1]	'	'
Excluding Life Funds Withheld Assets | CDO	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	763,146		'	'
Gross unrealized gains on Fixed maturities	3,656		'	'
Gross unrealized losses on Fixed maturities	-28,729		'	'
Fixed maturities, at fair value	738,073		'	'
Gross Unrealized Losses Non-credit related OTTI	-1,812	[1]	'	'
Excluding Life Funds Withheld Assets | Other asset-backed securities	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	1,271,201		'	'
Gross unrealized gains on Fixed maturities	42,158	[11]	'	'
Gross unrealized losses on Fixed maturities	-3,087	[11]	'	'
Fixed maturities, at fair value	1,310,272		'	'
Gross Unrealized Losses Non-credit related OTTI	-2,058	[1],[11]	'	'
Excluding Life Funds Withheld Assets | U.S. States and political subdivisions of the States	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	1,836,889		'	'
Gross unrealized gains on Fixed maturities	109,258		'	'
Gross unrealized losses on Fixed maturities	-6,557		'	'
Fixed maturities, at fair value	1,939,590		'	'
Gross Unrealized Losses Non-credit related OTTI	0	[1]	'	'
Excluding Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	4,264,089		'	'
Gross unrealized gains on Fixed maturities	117,877	[2]	'	'
Gross unrealized losses on Fixed maturities	-26,105	[2]	'	'
Fixed maturities, at fair value	4,355,861		'	'
Gross Unrealized Losses Non-credit related OTTI	0	[1],[2]	'	'
Life Funds Withheld Assets	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	4,839,071		'	'
Gross unrealized gains on Fixed maturities	605,300		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	5,444,371		'	0
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | U.S. Government and Government - Related/Supported	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	16,356		'	'
Gross unrealized gains on Fixed maturities	1,869		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	18,225		'	'
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | Corporate	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	2,722,907		'	'
Gross unrealized gains on Fixed maturities	294,539		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	3,017,446		'	'
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | RMBS - Agency	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	3,990		'	'
Gross unrealized gains on Fixed maturities	33		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	4,023		'	'
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | RMBS - Non-Agency	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	78,804		'	'
Gross unrealized gains on Fixed maturities	9,300		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	88,104		'	'
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | CMBS	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	198,576		'	'
Gross unrealized gains on Fixed maturities	18,268		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	216,844		'	'
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | CDO	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	0		'	'
Gross unrealized gains on Fixed maturities	0		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	0		'	'
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | Other asset-backed securities	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	271,691		'	'
Gross unrealized gains on Fixed maturities	21,926		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	293,617		'	'
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | U.S. States and political subdivisions of the States	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	0		'	'
Gross unrealized gains on Fixed maturities	0		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	0		'	'
Gross Unrealized Losses Non-credit related OTTI	0		'	'
Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'		'	'
AFS securities	'		'	'
Cost or amortized cost of Fixed maturities	1,546,747		'	'
Gross unrealized gains on Fixed maturities	259,365		'	'
Gross unrealized losses on Fixed maturities	0		'	'
Fixed maturities, at fair value	1,806,112		'	'
Gross Unrealized Losses Non-credit related OTTI	$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]	U.S. Government and Government-Related/Supported, Non-U.S. Sovereign Government, Provincials, Supranationals and Government-Related/Supported and Total short-term investments includes government-related securities with an amortized cost of $1,679.1 million and fair value of $1,721.8 million and U.S. Agencies with an amortized cost of $230.2 million and fair value of $256.8 million.
[3]	U.S. Government and Government-Related/Supported, Non-U.S. Sovereign Government, Provincials, Supranationals and Government-Related/Supported and Total short-term investments includes government-related securities with an amortized cost of $2,241.5 million and fair value of $2,275.6 million and U.S. Agencies with an amortized cost of $267.0 million and fair value of $284.3 million.
[4]	Included within Total equity securities are investments in fixed income funds with a fair value of $92.1 million and an amortized cost of $92.1 million.
[5]	Included within Total equity securities are investments in fixed income funds with a fair value of $87.4 million and an amortized cost of $100.0 million.
[6]	Included within Corporate 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 $154.6 million and an amortized cost of $147.7 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 values of these notes.
[7]	Included within Corporate are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions. These securities have a fair value of $282.2 million and an amortized cost of $286.2 million.
[8]	Covered Bonds within Fixed maturities - AFS with an amortized cost of $526.4 million and a fair value of $553.1 million and Covered Bonds within Fixed maturities - HTM with an amortized cost of $8.6 million and a fair value of $8.7 million are included within Other asset-backed securities to align the Company's classification to market indices.
[9]	Included within Corporate are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions. These securities have a fair value of $28.1 million and an amortized cost of $32.6 million.
[10]	Included within Corporate 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 $155.9 million and an amortized cost of $143.6 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 values of these notes.
[11]	Covered Bonds with an amortized cost of $737.0 million and a fair value of $763.6 million are included within Other asset-backed securities to align the Company's classification to market indices.

Investments_Contractual_maturi

Investments - Contractual maturities of available for sale securities and held to maturity income securities (Details) (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Fixed Maturities - AFS	'		'
Due less than one year, amortized cost	'		$2,052,251	[1]
Due less than one year, fair value	'		2,060,365	[1]
Due after 1 through 5 years, amortized cost	'		10,075,087	[1]
Due after 1 through 5 years, fair value	'		10,305,986	[1]
Due after 5 through 10 years, amortized cost	'		5,474,120	[1]
Due after 5 through 10 years, fair value	'		5,507,450	[1]
Due after 10 years, amortized cost	'		2,385,406	[1]
Due after 10 years, fair value	'		2,475,233	[1]
Subtotal - amortized cost	'		19,986,864	[1]
Subtotal - fair value	'		20,349,034
Mortgage and asset backed securities - amortized cost	'		7,125,010	[1]
Mortgage and asset backed securities - fair value	'		7,151,102	[1]
Amortized cost of Fixed maturities	29,065,531		27,111,874
Fixed maturities, at fair value	30,442,921		27,500,136
Fixed maturities - HTM	'		'
Due less than one year, amortized cost	0	[1]	65,651	[1]
Due less than one year, fair value	0	[1]	66,766	[1]
Due after 1 through 5 years, amortized cost	0	[1]	240,802	[1]
Due after 1 through 5 years, fair value	0	[1]	255,322	[1]
Due after 5 through 10 years, amortized cost	0	[1]	455,633	[1]
Due after 5 through 10 years, fair value	0	[1]	492,095	[1]
Due after 10 years, amortized cost	0	[1]	1,778,158	[1]
Due after 10 years, fair value	0	[1]	1,974,844	[1]
Subtotal - amortized cost	0	[1]	2,540,244	[1]
Subtotal - fair value	0	[1]	2,789,027	[1]
Mortgage and asset backed securities - amortized cost	0	[1]	318,451	[1]
Mortgage and asset backed securities - fair value	0	[1]	342,208	[1]
Fixed maturities, held to maturity	0		2,858,695
Fair value of held to maturity securities	0		3,131,235
RMBS - Agency	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	'		3,540,101	[1]
Mortgage and asset backed securities - fair value	'		3,546,122	[1]
Fixed maturities, at fair value	'		3,546,122
RMBS - Non-Agency	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	'		396,798	[1]
Mortgage and asset backed securities - fair value	'		398,768	[1]
Fixed maturities, at fair value	'		398,768
Fixed maturities - HTM	'		'
Mortgage and asset backed securities - amortized cost	0	[1]	66,987	[1]
Mortgage and asset backed securities - fair value	0	[1]	71,972	[1]
Fixed maturities, held to maturity	0		66,987
Fair value of held to maturity securities	'		71,972
CMBS	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	'		1,223,313	[1]
Mortgage and asset backed securities - fair value	'		1,246,795	[1]
Fixed maturities, at fair value	'		1,246,795
Fixed maturities - HTM	'		'
Mortgage and asset backed securities - amortized cost	0	[1]	144,924	[1]
Mortgage and asset backed securities - fair value	0	[1]	156,788	[1]
Fixed maturities, held to maturity	0		144,924
Fair value of held to maturity securities	'		156,788
CDO	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	'		754,414	[1]
Mortgage and asset backed securities - fair value	'		717,313	[1]
Fixed maturities, at fair value	'		717,313
Other asset-backed securities	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	'		1,210,384	[1]
Mortgage and asset backed securities - fair value	'		1,242,104	[1]
Fixed maturities, at fair value	'		1,242,104
Fixed maturities - HTM	'		'
Mortgage and asset backed securities - amortized cost	0	[1]	106,540	[1]
Mortgage and asset backed securities - fair value	0	[1]	113,448	[1]
Fixed maturities, held to maturity	0		106,540
Fair value of held to maturity securities	'		113,448
Excluding Life Funds Withheld Assets	'		'
Fixed Maturities - AFS	'		'
Due less than one year, amortized cost	2,069,219	[1]	'
Due less than one year, fair value	2,088,394	[1]	'
Due after 1 through 5 years, amortized cost	9,384,790	[1]	'
Due after 1 through 5 years, fair value	9,657,635	[1]	'
Due after 5 through 10 years, amortized cost	4,518,798	[1]	'
Due after 5 through 10 years, fair value	4,693,075	[1]	'
Due after 10 years, amortized cost	1,506,977	[1]	'
Due after 10 years, fair value	1,668,265	[1]	'
Subtotal - amortized cost	17,479,784	[1]	'
Subtotal - fair value	18,107,369	[1]	'
Mortgage and asset backed securities - amortized cost	6,746,676	[1]	'
Mortgage and asset backed securities - fair value	6,891,181	[1]	'
Amortized cost of Fixed maturities	24,226,460		'
Fixed maturities, at fair value	24,998,550		'
Excluding Life Funds Withheld Assets | RMBS - Agency	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	3,218,551	[1]	'
Mortgage and asset backed securities - fair value	3,303,046	[1]	'
Fixed maturities, at fair value	3,303,046		'
Excluding Life Funds Withheld Assets | RMBS - Non-Agency	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	395,629	[1]	'
Mortgage and asset backed securities - fair value	415,503	[1]	'
Fixed maturities, at fair value	415,503		'
Excluding Life Funds Withheld Assets | CMBS	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	1,098,149	[1]	'
Mortgage and asset backed securities - fair value	1,124,287	[1]	'
Fixed maturities, at fair value	1,124,287		'
Excluding Life Funds Withheld Assets | CDO	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	763,146	[1]	'
Mortgage and asset backed securities - fair value	738,073	[1]	'
Fixed maturities, at fair value	738,073		'
Excluding Life Funds Withheld Assets | Other asset-backed securities	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	1,271,201	[1]	'
Mortgage and asset backed securities - fair value	1,310,272	[1]	'
Fixed maturities, at fair value	1,310,272		'
Life Funds Withheld Assets	'		'
Fixed Maturities - AFS	'		'
Due less than one year, amortized cost	138,250		0
Due less than one year, fair value	144,169		0
Due after 1 through 5 years, amortized cost	680,192		0
Due after 1 through 5 years, fair value	725,237		0
Due after 5 through 10 years, amortized cost	1,159,277		0
Due after 5 through 10 years, fair value	1,297,027		0
Due after 10 years, amortized cost	2,308,291		0
Due after 10 years, fair value	2,675,350		0
Subtotal - amortized cost	4,286,010		0
Subtotal - fair value	4,841,783		0
Mortgage and asset backed securities - amortized cost	553,061		0
Mortgage and asset backed securities - fair value	602,588		0
Amortized cost of Fixed maturities	4,839,071		0
Fixed maturities, at fair value	5,444,371		0
Life Funds Withheld Assets | RMBS - Agency	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	3,990		0
Mortgage and asset backed securities - fair value	4,023		0
Fixed maturities, at fair value	4,023		'
Life Funds Withheld Assets | RMBS - Non-Agency	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	78,804		0
Mortgage and asset backed securities - fair value	88,104		0
Fixed maturities, at fair value	88,104		'
Life Funds Withheld Assets | CMBS	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	198,576		0
Mortgage and asset backed securities - fair value	216,844		0
Fixed maturities, at fair value	216,844		'
Life Funds Withheld Assets | CDO	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	0		0
Mortgage and asset backed securities - fair value	0		0
Fixed maturities, at fair value	0		'
Life Funds Withheld Assets | Other asset-backed securities	'		'
Fixed Maturities - AFS	'		'
Mortgage and asset backed securities - amortized cost	271,691		0
Mortgage and asset backed securities - fair value	293,617		0
Fixed maturities, at fair value	$293,617		'
[1]	Included in the table above within Fixed Maturities - AFS - Excluding Life Funds Withheld Assets, are Tier One and Upper Tier Two securities, representing committed term debt and hybrid instruments, which are senior to the common and preferred equities of the financial institutions, at their fair values of $28.1 million and $282.2 million at JuneB 30, 2014 and DecemberB 31, 2013, respectively. These securities are reflected in the table based on their call date and have net unrealized losses of $4.5 million and $4.0 million at JuneB 30, 2014 and DecemberB 31, 2013, respectively.

Investments_Analysis_of_contin

Investments - Analysis of continual unrealized loss position (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
HTM securities	'	'
Less than 12 months Fair Value	$0	$46,034
Less than 12 months Gross Unrealized Losses	0	-941
Equal to or greater than 12 months Fair Value	0	12,536
Equal to or greater than 12 months Gross Unrealized Losses	0	-669
Fixed Maturities And Short Term Investments Available For Sale [Member]	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	1,497,246	8,871,868
Less than 12 months Gross Unrealized Losses	-14,124	-230,109
Equal to or greater than 12 months Fair Value	3,657,539	2,117,444
Equal to greater than 12 months Gross Unrealized Losses	-152,497	-189,457
U.S. Government and Government - Related/Supported	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	1,333,704
Less than 12 months Gross Unrealized Losses	'	-30,474
Equal to or greater than 12 months Fair Value	'	44,158
Equal to greater than 12 months Gross Unrealized Losses	'	-3,614
Corporate	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	2,756,235
Less than 12 months Gross Unrealized Losses	'	-59,497
Equal to or greater than 12 months Fair Value	'	513,106
Equal to greater than 12 months Gross Unrealized Losses	'	-50,160
HTM securities	'	'
Less than 12 months Fair Value	'	46,034
Less than 12 months Gross Unrealized Losses	'	-941
Equal to or greater than 12 months Fair Value	'	642
Equal to or greater than 12 months Gross Unrealized Losses	'	-27
RMBS - Agency	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	1,485,261
Less than 12 months Gross Unrealized Losses	'	-50,362
Equal to or greater than 12 months Fair Value	'	169,704
Equal to greater than 12 months Gross Unrealized Losses	'	-11,715
RMBS - Non-Agency	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	14,204
Less than 12 months Gross Unrealized Losses	'	-604
Equal to or greater than 12 months Fair Value	'	240,946
Equal to greater than 12 months Gross Unrealized Losses	'	-30,522
CMBS	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	432,820
Less than 12 months Gross Unrealized Losses	'	-6,816
Equal to or greater than 12 months Fair Value	'	107,192
Equal to greater than 12 months Gross Unrealized Losses	'	-8,957
CDO	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	58,239
Less than 12 months Gross Unrealized Losses	'	-217
Equal to or greater than 12 months Fair Value	'	574,613
Equal to greater than 12 months Gross Unrealized Losses	'	-42,717
Other asset-backed securities	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	196,639
Less than 12 months Gross Unrealized Losses	'	-2,149
Equal to or greater than 12 months Fair Value	'	96,528
Equal to greater than 12 months Gross Unrealized Losses	'	-6,691
U.S. States and political subdivisions of the States	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	463,974
Less than 12 months Gross Unrealized Losses	'	-23,124
Equal to or greater than 12 months Fair Value	'	64,324
Equal to greater than 12 months Gross Unrealized Losses	'	-7,646
Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	'	2,130,792
Less than 12 months Gross Unrealized Losses	'	-56,866
Equal to or greater than 12 months Fair Value	'	306,873
Equal to greater than 12 months Gross Unrealized Losses	'	-27,435
HTM securities	'	'
Less than 12 months Fair Value	'	0
Less than 12 months Gross Unrealized Losses	'	0
Equal to or greater than 12 months Fair Value	'	11,894
Equal to or greater than 12 months Gross Unrealized Losses	'	-642
Equities	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	46,158	155,453
Less than 12 months Gross Unrealized Losses	-2,624	-17,470
Equal to or greater than 12 months Fair Value	0	0
Equal to greater than 12 months Gross Unrealized Losses	0	0
Excluding Life Funds Withheld Assets | Fixed Maturities And Short Term Investments Available For Sale [Member]	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	1,497,246	'
Less than 12 months Gross Unrealized Losses	-14,124	'
Equal to or greater than 12 months Fair Value	3,657,539	'
Equal to greater than 12 months Gross Unrealized Losses	-152,497	'
Excluding Life Funds Withheld Assets | U.S. Government and Government - Related/Supported	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	155,192	'
Less than 12 months Gross Unrealized Losses	-1,345	'
Equal to or greater than 12 months Fair Value	455,830	'
Equal to greater than 12 months Gross Unrealized Losses	-7,926	'
Excluding Life Funds Withheld Assets | Corporate	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	510,313	'
Less than 12 months Gross Unrealized Losses	-4,910	'
Equal to or greater than 12 months Fair Value	820,499	'
Equal to greater than 12 months Gross Unrealized Losses	-38,302	'
Excluding Life Funds Withheld Assets | RMBS - Agency	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	28,954	'
Less than 12 months Gross Unrealized Losses	-123	'
Equal to or greater than 12 months Fair Value	652,745	'
Equal to greater than 12 months Gross Unrealized Losses	-20,256	'
Excluding Life Funds Withheld Assets | RMBS - Non-Agency	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	26,501	'
Less than 12 months Gross Unrealized Losses	-374	'
Equal to or greater than 12 months Fair Value	216,406	'
Equal to greater than 12 months Gross Unrealized Losses	-20,806	'
Excluding Life Funds Withheld Assets | CMBS	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	65,205	'
Less than 12 months Gross Unrealized Losses	-197	'
Equal to or greater than 12 months Fair Value	202,685	'
Equal to greater than 12 months Gross Unrealized Losses	-7,227	'
Excluding Life Funds Withheld Assets | CDO	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	69,479	'
Less than 12 months Gross Unrealized Losses	-268	'
Equal to or greater than 12 months Fair Value	492,272	'
Equal to greater than 12 months Gross Unrealized Losses	-28,461	'
Excluding Life Funds Withheld Assets | Other asset-backed securities	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	60,338	'
Less than 12 months Gross Unrealized Losses	-130	'
Equal to or greater than 12 months Fair Value	79,464	'
Equal to greater than 12 months Gross Unrealized Losses	-2,957	'
Excluding Life Funds Withheld Assets | U.S. States and political subdivisions of the States	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	32,636	'
Less than 12 months Gross Unrealized Losses	-260	'
Equal to or greater than 12 months Fair Value	222,479	'
Equal to greater than 12 months Gross Unrealized Losses	-6,297	'
Excluding Life Funds Withheld Assets | Non-U.S. Sovereign Government, Provincial, Supranational, and Government-Related/Supported	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	548,628	'
Less than 12 months Gross Unrealized Losses	-6,517	'
Equal to or greater than 12 months Fair Value	515,159	'
Equal to greater than 12 months Gross Unrealized Losses	-20,265	'
Life Funds Withheld Assets | Fixed Maturities And Short Term Investments Available For Sale [Member]	'	'
Fixed maturities and short-term investments - AFS:	'	'
Less than 12 months Fair Value	0	'
Less than 12 months Gross Unrealized Losses	0	'
Equal to or greater than 12 months Fair Value	0	'
Equal to greater than 12 months Gross Unrealized Losses	$0	'

Investments_Analysis_of_net_re

Investments - Analysis of net realized gains (losses) and the change in unrealized (losses) gains on investments (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net realized gains (losses): [Abstract]	'	'	'	'
Net realized gains (losses) on investments	$72,697	$40,968	$91,926	$77,477
Excluding Life Funds Withheld Assets	'	'	'	'
Net realized gains (losses): [Abstract]	'	'	'	'
Gross realized gains	118,947	64,865	170,160	138,038
Gross realized losses on investments sold	-13,487	-21,508	-41,744	-53,534
OTTI on investments, net of amounts transferred to other comprehensive income	-24,616	-2,389	-28,343	-7,027
Net realized gains (losses) on investments	80,844	40,968	100,073	77,477
Life Funds Withheld Assets	'	'	'	'
Net realized gains (losses): [Abstract]	'	'	'	'
Gross realized gains	624	0	624	0
Gross realized losses on investments sold	0	0	0	0
OTTI on investments, net of amounts transferred to other comprehensive income	-8,771	0	-8,771	0
Net realized gains (losses) on investments	($8,147)	$0	($8,147)	$0

Investments_Credit_loss_impair

Investments - Credit loss impairments on fixed income securities (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'	'	'	'
Balance, beginning of period	$171,382	$260,066	$174,805	$268,707
Credit loss impairment recognized in the current period on securities not previously impaired	30	27	41	527
Credit loss impairments previously recognized on securities which matured, paid down, prepaid or were sold during the period	-3,322	-55,144	-7,571	-61,619
Credit loss impairments previously recognized on securities impaired to fair value during the period	0	0	0	0
Additional credit loss impairments recognized in the current period on securities previously impaired	892	1,996	3,153	4,300
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	-3,105	-4,083	-4,551	-9,053
Balance, end of period	$165,877	$202,862	$165,877	$202,862

Investments_Narrative_Details

Investments - Narrative (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	1-May-14	Dec. 31, 2013
	positions		positions
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	$0	'	$0	'	$424,861,000	$274,150,000
Fixed maturites held to maturity, gross unrealized losses	0	'	0	'	0	1,610,000
Fixed maturities, at fair value	30,442,921,000	'	30,442,921,000	'	'	27,500,136,000
Percentage of Gross Unrealized losses in Fixed income securities portfolio related to securities below investment grade or not rated	22.00%	'	22.00%	'	'	12.40%
Investments In Structured Transactions Not Carried at Fair Value	275,821,000	'	275,821,000	'	'	294,048,000
Fixed maturities, held to maturity	0	'	0	'	'	2,858,695,000
Fair value of held to maturity securities	0	'	0	'	'	3,131,235,000
Amortized cost of fixed maturities	29,065,531,000	'	29,065,531,000	'	'	27,111,874,000
Equity securities, at fair value	988,710,000	'	988,710,000	'	'	1,040,237,000
Cost of equity securities	839,716,000	'	839,716,000	'	'	903,201,000
Percentage of Fixed Income Investment portfolio invested in below investment grade or not rated	2.80%	'	2.80%	'	'	2.60%
Pledged Assets Separately Reported, Other Debt Securities Available-for-sale or Held-for-investment	16,100,000,000	'	16,100,000,000	'	'	15,500,000,000
Available for sale securities, Gross unrealized losses	169,245,000	'	169,245,000	'	'	437,036,000
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	1,385	'	1,385	'	'	'
Available-for-sale Securities, Qualitative Disclosure, Number of Positions	7,668	'	7,668	'	'	'
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	3,322,000	55,144,000	7,571,000	61,619,000	'	'
Government Related Securities [Member]	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Marketable Securities Cost Or Amortized Cost	1,679,100,000	'	1,679,100,000	'	'	2,241,500,000
Marketable Securities	1,721,800,000	'	1,721,800,000	'	'	2,275,600,000
Agency Securities	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Marketable Securities Cost Or Amortized Cost	230,200,000	'	230,200,000	'	'	267,000,000
Marketable Securities	256,800,000	'	256,800,000	'	'	284,300,000
Covered bonds	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Fixed maturities, at fair value	763,600,000	'	763,600,000	'	'	553,100,000
Fixed maturities, held to maturity	'	'	'	'	'	8,600,000
Fair value of held to maturity securities	'	'	'	'	'	8,700,000
Amortized cost of fixed maturities	737,000,000	'	737,000,000	'	'	526,400,000
Corporate	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	'	'	'	'	'	113,179,000
Fixed maturites held to maturity, gross unrealized losses	'	'	'	'	'	968,000
Fixed maturities, at fair value	'	'	'	'	'	11,125,830,000
Fixed maturities, held to maturity	'	'	'	'	'	1,386,863,000
Fair value of held to maturity securities	'	'	'	'	'	1,499,074,000
Amortized cost of fixed maturities	'	'	'	'	'	10,802,332,000
Medium term notes	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Fixed maturities, at fair value	155,900,000	'	155,900,000	'	'	154,600,000
Amortized cost of fixed maturities	143,600,000	'	143,600,000	'	'	147,700,000
Tier One And Upper Tier Two Securities	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Marketable Securities Cost Or Amortized Cost	32,600,000	'	32,600,000	'	'	286,200,000
Marketable Securities	28,100,000	'	28,100,000	'	'	282,200,000
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In Investments	4,500,000	'	4,500,000	'	'	4,000,000
Fixed income funds	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Equity securities, at fair value	92,100,000	'	92,100,000	'	'	87,400,000
Cost of equity securities	92,100,000	'	92,100,000	'	'	100,000,000
Structured Credit Securities [Member]	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Marketable Securities	4,600,000	'	4,600,000	'	'	'
Impaired Investment Cumulative Fair Value Decline Percentage Amortized Cost	50.00%	'	50.00%	'	'	'
Marketable Securities Unrealized Loss Other Than Temporary Impairments Amount	10,600,000	'	10,600,000	'	'	'
RMBS - Non-Agency	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	'	'	'	'	'	4,985,000
Fixed maturites held to maturity, gross unrealized losses	'	'	'	'	'	0
Fixed maturities, at fair value	'	'	'	'	'	398,768,000
Fixed maturities, held to maturity	0	'	0	'	'	66,987,000
Fair value of held to maturity securities	'	'	'	'	'	71,972,000
Amortized cost of fixed maturities	'	'	'	'	'	396,798,000
Marketable Securities Unrealized Loss Other Than Temporary Impairments Amount	200,000	'	200,000	'	'	'
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	2,500,000	54,400,000	5,200,000	60,200,000	'	'
CMBS	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Unrealized gains on held to maturity investment portfolio at time of transfer to available for sale, net of tax	'	'	'	'	'	11,864,000
Fixed maturites held to maturity, gross unrealized losses	'	'	'	'	'	0
Fixed maturities, at fair value	'	'	'	'	'	1,246,795,000
Fixed maturities, held to maturity	0	'	0	'	'	144,924,000
Fair value of held to maturity securities	'	'	'	'	'	156,788,000
Amortized cost of fixed maturities	'	'	'	'	'	1,223,313,000
Core Cdo Holdings	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Marketable Securities Unrealized Loss Other Than Temporary Impairments Amount	10,400,000	'	10,400,000	'	'	'
XL Re Life (SAC) Ltd [Member]	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Held To Maturity Securities Transferred Security Carrying Value	2,800,000,000	'	2,800,000,000	'	'	'
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	440,461,000	32,900,000	474,461,000	32,900,000	'	'
Excluding Life Funds Withheld Assets	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Fixed maturities, at fair value	24,998,550,000	'	24,998,550,000	'	'	'
Amortized cost of fixed maturities	24,226,460,000	'	24,226,460,000	'	'	'
Available for sale securities, Gross unrealized losses	169,245,000	'	169,245,000	'	'	'
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	24,616,000	2,389,000	28,343,000	7,027,000	'	'
Excluding Life Funds Withheld Assets | Corporate	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Fixed maturities, at fair value	9,727,624,000	'	9,727,624,000	'	'	'
Amortized cost of fixed maturities	9,345,654,000	'	9,345,654,000	'	'	'
Excluding Life Funds Withheld Assets | RMBS - Non-Agency	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Fixed maturities, at fair value	415,503,000	'	415,503,000	'	'	'
Amortized cost of fixed maturities	395,629,000	'	395,629,000	'	'	'
Excluding Life Funds Withheld Assets | 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	12,500,000	'	'	'	'	'
Excluding Life Funds Withheld Assets | CMBS	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Fixed maturities, at fair value	1,124,287,000	'	1,124,287,000	'	'	'
Amortized cost of fixed maturities	1,098,149,000	'	1,098,149,000	'	'	'
Excluding Life Funds Withheld Assets | Equities	'	'	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'	'	'
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	$10,300,000	'	'	'	'	'

Derivative_Instruments_Gross_a

Derivative Instruments - Gross amounts of derivative fair values contained in the consolidated balance sheet (Details) (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'		'
Gross amounts recognized in balance sheet	$60,570		$27,487
Asset derivative fair value	59,330		26,145
Gross amounts recognized in balance sheet	69,640		105,485
Liability derivative fair value	68,400		104,143
Derivatives designated as hedging instruments | Foreign exchange contracts	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	891,217		1,005,610
Gross amounts recognized in balance sheet	45,597	[1]	26,098	[1]
Liability derivative notional amount	1,315,385		2,572,227
Gross amounts recognized in balance sheet	35,265	[1]	70,462	[1]
Derivatives not designated as hedging instruments	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	1,653,871		172,800
Gross amounts recognized in balance sheet	14,973	[1]	1,389	[1]
Liability derivative notional amount	5,943,417		513,512
Gross amounts recognized in balance sheet	34,375	[1]	35,023	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Interest rate exposure	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	1,295,267		30,702
Gross amounts recognized in balance sheet	259	[1]	266	[1]
Liability derivative notional amount	28,090		10,259
Gross amounts recognized in balance sheet	0	[1]	8	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Foreign exchange contracts	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	190,870		17,497
Gross amounts recognized in balance sheet	1,914	[1]	12	[1]
Liability derivative notional amount	105,797		50,614
Gross amounts recognized in balance sheet	3,004	[1]	680	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Credit exposure	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	4,566		0
Gross amounts recognized in balance sheet	3	[1]	0	[1]
Liability derivative notional amount	14,270		340,020
Gross amounts recognized in balance sheet	9,988	[1]	15,128	[1]
Derivatives not designated as hedging instruments | Investment related derivatives | Financial market exposure	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	46,645		58,232
Gross amounts recognized in balance sheet	344	[1]	1,111	[1]
Liability derivative notional amount	43,468		14,821
Gross amounts recognized in balance sheet	0	[1]	77	[1]
Derivatives not designated as hedging instruments | Financial operations derivatives | Credit exposure	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	0	[2]	0	[2]
Gross amounts recognized in balance sheet	0	[1],[2]	0	[1],[2]
Liability derivative notional amount	41,346	[2]	44,234	[2]
Gross amounts recognized in balance sheet	8,930	[1],[2]	4,190	[1],[2]
Derivatives not designated as hedging instruments | Other non-investment derivatives | Guaranteed minimum income benefit contract	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	50,802		0
Gross amounts recognized in balance sheet	12,453	[1]	0	[1]
Liability derivative notional amount	50,802		53,564
Gross amounts recognized in balance sheet	12,453	[1]	14,940	[1]
Derivatives not designated as hedging instruments | Other non-investment derivatives | Modified coinsurance funds withheld contract	'		'
Derivatives, Fair Value [Line Items]	'		'
Asset derivative notional amount	65,721	[3]	66,369	[3]
Gross amounts recognized in balance sheet	0	[1],[3]	0	[1],[3]
Liability derivative notional amount	5,659,644	[3]	0	[3]
Gross amounts recognized in balance sheet	$0	[1],[3]	$0	[1],[3]
[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 intentions to settle the contracts on a net basis.
[2]	Financial operations derivatives represent interests in variable interest entities as described in Note 12, bVariable Interest Entities".
[3]	The fair value movements in derivative assets and liabilities relating to modified coinsurance funds withheld contracts are included within the 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.

Derivative_Instruments_Balance

Derivative Instruments - Balance sheet offsetting (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative assets:	'	'
Gross amounts recognized in balance sheet	$60,570	$27,487
Gross amounts offset in balance sheet	1,240	1,342
Net amounts in the balance sheet	59,330	26,145
Gross amounts not offset in the balance sheet - financial instruments	0	0
Gross amounts not offset in the balance sheet - cash collateral	3,160	0
Derivative Asset	56,170	26,145
Derivative liabilities:	'	'
Gross amounts recognized in balance sheet	69,640	105,485
Gross amounts offset in balance sheet	1,240	1,342
Net amounts in the balance sheet	68,400	104,143
Gross amounts not offset in the balance sheet - financial instruments	0	0
Gross amounts not offset in the balance sheet - cash collateral	0	19,847
Derivative Liability	$68,400	$84,296

Derivative_Instruments_Derivat

Derivative Instruments - Derivatives Designated As Fair Value Hedges (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of gain (loss) recognized in income from ineffective portion of fair value hedges	($2,050)	($506)	($256)	$969
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	-9,132	-5,002	-15,663	25,243
Amount of gain (loss) recognized in income from ineffective portion of fair value hedges	-2,050	-506	-256	969
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	0	0	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	-9,132	-5,002	-15,663	25,243
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	$7,082	$4,496	$15,407	($24,274)

Derivative_Instruments_Schedul

Derivative Instruments - Schedule of settlement of fair value hedges (Details) (Fair value hedges, USD $)	3 Months Ended	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Notes payable and debt	'	'
Derivative [Line Items]	'	'
Cumulative reduction to interest expense	$20,810	$16,903
Remaining balance	814	4,721
Weighted average years remaining to maturity	'0 years 2 months 12 days	'1 year 2 months 12 days
Deposit liabilities	'	'
Derivative [Line Items]	'	'
Cumulative reduction to interest expense	90,615	29,257
Remaining balance	$142,580	$203,938
Weighted average years remaining to maturity	'24 years 0 months 0 days	'24 years 2 months 12 days

Derivative_Instruments_Derivat1

Derivative Instruments - Derivative Instruments Designated as Hedges of the net Investment In a Foreign Operation - Summary (Details) (Derivatives designated as hedging instruments, USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivatives designated as hedging instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Weighted average of U.S. dollar equivalent of foreign denominated net assets	$2,270,090	$2,588,385	$2,478,772	$2,556,103
Derivative gains (losses)	($2,170)	($6,135)	($1,210)	$54,479

Derivative_Instruments_Net_Rea

Derivative Instruments - Net Realized and unrealized gains (losses) on Derivative Instruments (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative [Line Items]	'	'	'	'
Amount of gain (loss) recognized in income from ineffective portion of fair value hedges	($2,050)	($506)	($256)	$969
Net realized and unrealized gains (losses) on derivative instruments	11,599	-5,105	13,409	2,780
Derivatives not designated as hedging instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Total gain (loss) recognized in income from derivatives not designated as hedging instruments	13,649	-4,599	13,665	1,811
Derivatives not designated as hedging instruments | Investment related derivatives	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate exposure	8,978	288	9,326	489
Foreign exchange exposure	-1,490	-2,690	1,798	-4,288
Credit exposure	411	-1,178	7	-1,994
Financial market exposure	2,508	-2,736	3,378	2,616
Derivatives not designated as hedging instruments | Financial operations derivatives	'	'	'	'
Derivative [Line Items]	'	'	'	'
Credit exposure	447	1,087	-4,353	1,329
Derivatives not designated as hedging instruments | Other non-investment derivatives	'	'	'	'
Derivative [Line Items]	'	'	'	'
Guaranteed minimum income benefit contract	633	2,306	2,257	6,002
Modified coinsurance funds withheld contract	2,162	-1,676	1,252	-2,343
Life Funds Withheld Assets	'	'	'	'
Derivative [Line Items]	'	'	'	'
Net realized and unrealized gains (losses) on derivative instruments	($17,546)	$0	($17,546)	$0

Derivative_Instruments_Summary

Derivative Instruments - Summary of financial operations derivatives credit exposure (Details) (Credit exposure, Standard & Poor's, CC Rating, USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
	Contracts
Credit exposure | Standard & Poor's, CC Rating	'	'
Credit Derivatives [Line Items]	'	'
Derivative Liability, Number of Instruments Held	1	'
Principal outstanding	$39,748	$42,080
Interest outstanding	1,598	2,154
Aggregate outstanding exposure	41,346	44,234
Total liability recorded	$8,930	$4,190
Weighted average contractual term to maturity	'3 years 3 months 18 days	'3 years 8 months 12 days
Project Finance Loan Participation Deficiency Guarantee Percentage	68.00%	'

Derivative_Instruments_Compone

Derivative Instruments - Components of Life Retrocession Embedded Derivative (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative [Line Items]	'	'	'	'
Net realized and unrealized gains (losses) on derivative instruments	$11,599	($5,105)	$13,409	$2,780
Life Funds Withheld Assets	'	'	'	'
Derivative [Line Items]	'	'	'	'
Net realized and unrealized gains (losses) on derivative instruments	-17,546	0	-17,546	0
Life Funds Withheld Assets | Interest Income [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Net realized and unrealized gains (losses) on derivative instruments	-19,944	'	'	'
Life Funds Withheld Assets | Net realized and unrealized gains (losses) on derivative instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Net realized and unrealized gains (losses) on derivative instruments	1,893	'	'	'
Life Funds Withheld Assets | Other Income [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Net realized and unrealized gains (losses) on derivative instruments	$505	'	'	'

Derivative_Instruments_Summary1

Derivative Instruments - Summary of contingent credit features (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]	'	'
Collateral posted to counterparty	$0	$19,847
Contracts with downgrade provisions [Member]	'	'
Derivative [Line Items]	'	'
Aggregate fair value of derivative agreements with downgrade provisions in a net liability position	6,728	47,703
Collateral posted to counterparty	$0	$13,260

Derivative_Instruments_Narrati

Derivative Instruments - Narrative (Details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Dec. 31, 2013
Derivative [Line Items]	'		'		'		'		'
Net realized and unrealized gains (losses) on derivative instruments	$11,599		($5,105)		$13,409		$2,780		'
Gross amounts not offset in the balance sheet - cash collateral	3,160		'		3,160		'		0
Collateral posted to counterparty	0		'		0		'		19,847
Net results from structured products	34,885		6,053		42,838		11,229		'
Fair value hedges | Deposit liabilities	'		'		'		'		'
Derivative [Line Items]	'		'		'		'		'
Remaining balance	142,580		203,938		142,580		203,938		'
Total P&C	'		'		'		'		'
Derivative [Line Items]	'		'		'		'		'
Net results from structured products	34,885	[1]	6,053	[2]	42,838	[3]	11,229	[4]	'
Total P&C | Interest expense	'		'		'		'		'
Derivative [Line Items]	'		'		'		'		'
Net results from structured products	18,200		-12,100		7,400		-24,600		'
Structured Indemnity [Member] | Fair value hedges | Deposit liabilities	'		'		'		'		'
Derivative [Line Items]	'		'		'		'		'
Remaining balance	47,000		'		47,000		'		'
Structured Indemnity [Member] | Total P&C | Interest expense	'		'		'		'		'
Derivative [Line Items]	'		'		'		'		'
Net results from structured products	28,700		'		'		'		'
Life Funds Withheld Assets	'		'		'		'		'
Derivative [Line Items]	'		'		'		'		'
Net realized and unrealized gains (losses) on derivative instruments	($17,546)		$0		($17,546)		$0		'
[1]	The net results from structured products include net investment income and interest expense (credit) of $16.9 million and $(18.2) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
[2]	The net results from structured products include net investment income and interest expense of $18.1 million and $12.1 million, respectively.
[3]	The net results from structured products include net investment income and net interest expense (credit) of $35.7 million and $(7.4) million, respectively. Net results from structured products includes a benefit of $28.7 million from a negotiated termination of one of the Company's larger structured indemnity contracts during the second quarter of 2014, producing a net interest expense credit.
[4]	The net results from structured products include net investment income and interest expense of $35.9 million and $24.6 million, respectively.

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'	'
Goodwill and intangible assets, net	$455,057	$411,611

Share_Capital_Options_valuatio

Share Capital - Options valuation assumptions (Details)	6 Months Ended
	Jun. 30, 2014
Stockholders' Equity Note [Abstract]	'
Dividend yield	1.99%
Risk free interest rate	1.80%
Volatility	33.80%
Expected lives	'6 years

Share_Capital_Narrative_Detail

Share Capital - Narrative (Details) (USD $)

0 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

12 Months Ended

6 Months Ended

Feb. 21, 2014

Jun. 30, 2014

Jun. 30, 2014

Feb. 21, 2014

Feb. 22, 2013

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

2014 Repurchase Authorization

2014 Repurchase Authorization

2014 Repurchase Authorization

2013 Repurchase Authorization

2013 Repurchase Authorization

2013 Repurchase Authorization

Stock options

Restricted Stock [Member]

Restricted stock units

Performance units

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Performance units

Performance units

Shareholders Equity Disclosure [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Repurchase Program, Authorized Amount

$1,000,000,000

'

'

'

$850,000,000

'

'

'

'

'

'

'

'

'

Stock Repurchased and Retired During Period, Shares

'

5,500,000

11,300,000

'

'

'

'

'

'

'

'

'

'

'

Stock Repurchased and Retired During Period, Value

'

175,000,000

350,000,000

'

'

'

'

'

'

'

'

'

'

'

Stock Repurchase Program, Remaining Authorized Repurchase Amount

'

'

717,600,000

200,000,000

'

275,000,000

'

'

'

'

'

'

'

'

Weighted Average Grant Date Fair Value Per Stock Option

'

'

'

'

'

'

$8.60

'

'

'

'

'

'

'

Number of Stock Options Granted During the Period

'

'

'

'

'

'

1,000,000

42,444

'

'

'

'

'

'

Number of Awards Granted During the Period

'

'

'

'

'

'

'

'

1,800,000

600,000

'

'

'

'

Aggregate Grant Date Fair Value of Award

'

'

'

'

'

'

'

$1,400,000

$54,300,000

$16,300,000

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period

'

'

'

'

'

'

'

'

'3 years

'3 years

'3 years

'

'4 years

'

Share Based Compensation Arrangement Performance Units Maximum Share Payout Number

'

'

'

'

'

'

'

'

'

1,100,000

'

'

'

'

Performance Units Final Payout Percentage Of Grant Amount

'

'

'

'

'

'

'

'

'

'

'

0.00%

'

200.00%

Notes_Payable_and_Debt_and_Fin2

Notes Payable and Debt and Financing Arrangements (Details) (USD $)

6 Months Ended

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Credit_Facilities

Revolving credit facility

Revolving credit facility

Letter of credit facilities

Letter of credit facilities

November 2013 unsecured credit agreement

Two Thousand Thirteen Citi Agreements [Member]

Two Thousand Thirteen Citi Agreements [Member]

Syndicated Credit Agreements [Member]

Revolving credit facility

Letter of credit facilities

Line of Credit Facility [Line Items]

'

'

'

'

'

'

'

'

'

Percentage Ownership Of XLIT Ltd.

100.00%

'

'

'

'

'

'

'

'

Available letter of credit facilities - commitments

'

$1,000,000,000

[1],[2]

$1,000,000,000

[1],[2]

$3,575,000,000

[1],[3]

$3,575,000,000

[1],[3]

'

$575,000,000

'

'

Available letter of credit facilities - in use

'

'

'

1,870,818,000

[1]

1,895,425,000

[1]

'

'

575,000,000

'

Collateralized by certain assets of the Companybs investment portfolio

'

'

'

67.20%

[1]

67.60%

[1]

'

'

'

'

Number Of Available Letter Of Credit

7

'

'

'

'

'

'

'

'

Line Of Credit Facility Optional Increased Capacity

'

'

'

'

'

$1,000,000,000

'

'

$500,000,000

[1]

At JuneB 30, 2014 and DecemberB 31, 2013, there were seven available letter of credit facilities.

[2]

At JuneB 30, 2014 and DecemberB 31, 2013,the revolving credit available under the November 2013 unsecured credit agreement, which provides for issuance of letters of credit and revolving credit loans up to $1 billion, was unutilized. The credit agreements entered into with Citicorp USA, Inc. in May through November 2013 (the "Citi Agreements") provide for issuance of letters of credit and revolving credit loans up to an aggregate amount of $575.0 million. At JuneB 30, 2014, $575.0 million of letters of credit were issued under these agreements and therefore such amount is not included in the table.

[3]

$500 million across such facilities. The Company also has the option to increase the maximum amount of the letters of credit and revolving credit loans available under the 2013 Citi Agreements with the lender's and issuing lender's consent.

Related_Party_Transactions_Sch

Related Party Transactions - Schedule of related party transactions activity (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
	management_company		management_company
Related Party Transaction [Line Items]	'	'	'	'
Reported net premiums written	$1,491,844	$1,533,868	$3,487,695	$3,641,522
Net losses and loss expenses incurred	827,880	937,606	1,659,385	1,780,690
Reported acquisition costs	184,619	231,886	384,033	452,145
Number of investment management companies	5	'	5	'
Investment manager affiliates	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'
Reported net premiums written	18,025	11,415	36,191	24,155
Net losses and loss expenses incurred	7,692	6,117	14,301	11,766
Reported acquisition costs	$6,994	$5,355	$15,553	$10,707

Variable_Interest_Entities_Det

Variable Interest Entities (Details) (Variable Interest Entity, Primary Beneficiary [Member], USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
New Ocean Capital Management Ltd [Member]	'	'
Variable Interest Entity [Line Items]	'	'
Noncontrolling Interest in Variable Interest Entity	$0.20	$0.30
New Ocean Focus Cat Fund [Member]	'	'
Variable Interest Entity [Line Items]	'	'
Noncontrolling Interest in Variable Interest Entity	29.6	6.9
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$89.30	$46.50

Computation_of_Earnings_Per_Or2

Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent - Computation of Basic and Diluted Earnings Per Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Basic earnings per ordinary share & ordinary share equivalents outstanding:	'	'	'	'
Net income (loss) attributable to ordinary shareholders	($279,261)	$272,698	($23,544)	$623,488
Weighted average ordinary shares outstanding - basic	270,924	289,513	273,616	292,277
Basic earnings per ordinary share & ordinary share equivalents outstanding	($1.03)	$0.94	($0.09)	$2.13
Diluted earnings per ordinary share & ordinary share equivalents outstanding:	'	'	'	'
Impact of share-based compensation and certain conversion features	0	4,820	0	4,767
Weighted average ordinary shares outstanding - diluted	270,924	294,333	273,616	297,044
Diluted earnings per ordinary share & ordinary share equivalents outstanding	($1.03)	$0.93	($0.09)	$2.10
Dividends per ordinary share	$0.16	$0.14	$0.32	$0.28

Computation_of_Earnings_Per_Or3

Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent - Narrative (Details) (Share-based compensation plans)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
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)	16.8	6	16.6	6.3

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	6 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
	Guarantee_contracts	Guarantee_contracts	Guarantee_contracts
Guarantor Obligations [Line Items]	'	'	'
Opening number of financial guarantee contracts	3	4	4
Number of financial guarantee contracts matured, prepaid or commuted during the period	0	'	-1
Closing number of financial guarantee contracts	3	'	3
Principal outstanding	$108,255	'	$108,255
Interest outstanding	0	'	0
Aggregate exposure outstanding	108,255	'	108,255
Total gross claim liability recorded	0	0	'
Total unearned premiums and fees recorded	$61	$134	'
Financial Guarantee Insurance Contracts Outstanding Weighted Average Contract Period	'25 years 7 months 6 days	'26 years 0 months 0 days	'
Financial Guarantee Related to Securities Including Some Issued By European Financials [Member]	'	'	'
Guarantor Obligations [Line Items]	'	'	'
Closing number of financial guarantee contracts	3	'	'

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) - Changes in AOCI, net of tax (Details) (USD $)	3 Months Ended			6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013	Jun. 30, 2014		Jun. 30, 2013	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'	'		'	'
Beginning balance, net of tax	$946,661,000		$1,405,122,000	$736,657,000		$1,520,020,000	'
OCI before Reclassifications	359,719,000		-726,980,000	619,039,000		-819,335,000	'
Amounts reclassified from AOCI	-72,587,000		-40,858,000	-91,706,000		-77,257,000	'
Tax benefit (expense)	-26,759,000		73,475,000	-56,956,000		87,331,000	'
Net current period OCI - net of tax	260,373,000		-694,363,000	470,377,000		-809,261,000	'
Ending balance, net of tax	1,207,034,000		710,759,000	1,207,034,000		710,759,000	'
Unrealized gains (losses) on investments	'		'	'		'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'	'		'	'
Beginning balance, net of tax	1,032,941,000	[1]	1,474,553,000	822,432,000	[1]	1,591,210,000	'
OCI before Reclassifications	363,348,000	[1]	-701,365,000	628,599,000	[1]	-789,054,000	'
Amounts reclassified from AOCI	-74,337,000	[1]	-55,408,000	-96,975,000	[1]	-97,102,000	'
Tax benefit (expense)	-20,774,000	[1]	71,671,000	-52,878,000	[1]	84,397,000	'
Net current period OCI - net of tax	268,237,000	[1]	-685,102,000	478,746,000	[1]	-801,759,000	'
Ending balance, net of tax	1,301,178,000	[1]	789,451,000	1,301,178,000	[1]	789,451,000	'
AOCI Other Details [Abstract]	'		'	'		'	'
Change in adjustments related to future policy benefit reserves, net of tax	-440,461,000		-32,900,000	-474,461,000		-32,900,000	'
Cumulative impact on value of future policy benefit reserve, end of period	519,200,000		'	519,200,000		'	44,700,000
OTTI losses recognized in AOCI	'		'	'		'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'	'		'	'
Beginning balance, net of tax	-85,894,000		-116,189,000	-89,190,000		-121,371,000	'
OCI before Reclassifications	0		0	0		0	'
Amounts reclassified from AOCI	1,640,000		14,440,000	5,049,000		19,625,000	'
Tax benefit (expense)	-4,000		-2,000	-117,000		-5,000	'
Net current period OCI - net of tax	1,636,000		14,438,000	4,932,000		19,620,000	'
Ending balance, net of tax	-84,258,000		-101,751,000	-84,258,000		-101,751,000	'
Foreign currency translation adjustments	'		'	'		'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'	'		'	'
Beginning balance, net of tax	10,661,000		65,480,000	14,541,000		69,399,000	'
OCI before Reclassifications	-3,621,000		-25,524,000	-9,521,000		-30,576,000	'
Amounts reclassified from AOCI	0		0	0		0	'
Tax benefit (expense)	-5,981,000		1,806,000	-3,961,000		2,939,000	'
Net current period OCI - net of tax	-9,602,000		-23,718,000	-13,482,000		-27,637,000	'
Ending balance, net of tax	1,059,000		41,762,000	1,059,000		41,762,000	'
Underfunded pension liability	'		'	'		'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'	'		'	'
Beginning balance, net of tax	-13,270,000		-20,506,000	-13,239,000		-20,892,000	'
OCI before Reclassifications	-8,000		-91,000	-39,000		295,000	'
Amounts reclassified from AOCI	0		0	0		0	'
Tax benefit (expense)	0		0	0		0	'
Net current period OCI - net of tax	-8,000		-91,000	-39,000		295,000	'
Ending balance, net of tax	-13,278,000		-20,597,000	-13,278,000		-20,597,000	'
Cash flow hedge	'		'	'		'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'	'		'	'
Beginning balance, net of tax	2,223,000		1,784,000	2,113,000		1,674,000	'
OCI before Reclassifications	0		0	0		0	'
Amounts reclassified from AOCI	110,000		110,000	220,000		220,000	'
Tax benefit (expense)	0		0	0		0	'
Net current period OCI - net of tax	110,000		110,000	220,000		220,000	'
Ending balance, net of tax	$2,333,000		$1,894,000	$2,333,000		$1,894,000	'
[1]	Included in these amounts are the impact of Shadow Adjustments. During the year ended December 31, 2013, the initial impact of $44.7 million was recorded. During the six months ended June 30, 2014, additional impacts of $474.5 million were recorded, resulting in a total cumulative impact of shadow adjustments on future policy benefit reserves of $519.2 million at JuneB 30, 2014.

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Loss) - Details About AOCI Components (Details) (USD $)	3 Months Ended			6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013	Jun. 30, 2014		Jun. 30, 2013
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'		'	'		'
Total before tax	($72,587)		($40,858)	($91,706)		($77,257)
Tax benefit (expense)	5,654		-28,872	-28,667		-72,351
Unrealized gains (losses) on investments	'		'	'		'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'		'	'		'
Net realized gains (losses) on investments sold	-107,470		-56,969	-132,384		-102,391
OTTI on investments	33,133		1,561	35,409		5,289
Total before tax	-74,337	[1]	-55,408	-96,975	[1]	-97,102
Tax benefit (expense)	1,477		-3,560	1,930		-3,286
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	-72,860		-58,968	-95,045		-100,388
OTTI losses recognized in AOCI	'		'	'		'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'		'	'		'
Total before tax	1,640		14,440	5,049		19,625
Accumulated Translation Adjustment [Member]	'		'	'		'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'		'	'		'
Total before tax	0		0	0		0
Accumulated Defined Benefit Plans Adjustment [Member]	'		'	'		'
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	110		110	220		220
Reclassification out of Accumulated Other Comprehensive Income [Member]	'		'	'		'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'		'	'		'
Total before tax	-72,587		-40,858	-91,706		-77,257
Tax benefit (expense)	1,473		-3,562	1,813		-3,291
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	-71,114		-44,420	-89,893		-80,548
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	1,386		13,612	3,344		17,887
OTTI on investments	254		828	1,705		1,738
Total before tax	1,640		14,440	5,049		19,625
Tax benefit (expense)	-4		-2	-117		-5
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1,636		14,438	4,932		19,620
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash flow hedge	'		'	'		'
Reclassification out of Accumulated Other Comprehensive Income [Line Items]	'		'	'		'
Total before tax	110		110	220		220
Tax benefit (expense)	0		0	0		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$110		$110	$220		$220
[1]	Included in these amounts are the impact of Shadow Adjustments. During the year ended December 31, 2013, the initial impact of $44.7 million was recorded. During the six months ended June 30, 2014, additional impacts of $474.5 million were recorded, resulting in a total cumulative impact of shadow adjustments on future policy benefit reserves of $519.2 million at JuneB 30, 2014.