AXIS Capital Holdings Limited (AXS) 10-Q 1 May 14 2014 Q1 Quarterly report Financial data

DOCUMENT_AND_ENTITY_INFORMATIO

DOCUMENT AND ENTITY INFORMATION	3 Months Ended
	Mar. 31, 2014	Apr. 23, 2014
DOCUMENT AND ENTITY INFORMATION [ABSTRACT]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Entity Registrant Name	'AXIS CAPITAL HOLDINGS LTD	'
Entity Central Index Key	'0001214816	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	107,769,353

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets	'	'
Fixed maturities, available for sale, at fair value (Amortized cost 2014: $12,023,304; 2013: $11,987,146)	$12,095,839	$11,986,327
Equity securities, available for sale, at fair value (Cost 2014: $581,473; 2013: $566,219)	708,412	701,987
Other investments, at fair value	1,005,762	1,045,810
Short-term investments, at fair value and amortized cost	296,800	46,212
Total investments	14,106,813	13,780,336
Cash and cash equivalents	1,205,754	923,326
Restricted cash and cash equivalents	88,955	64,550
Accrued interest receivable	89,536	97,132
Insurance and reinsurance premium balances receivable	2,292,954	1,688,957
Reinsurance recoverable on unpaid and paid losses	1,912,840	1,929,988
Deferred acquisition costs	634,413	456,122
Prepaid reinsurance premiums	299,994	330,261
Receivable for investments sold	1,972	1,199
Goodwill and intangible assets	90,350	89,528
Other assets	274,053	273,385
Total assets	20,997,634	19,634,784
Liabilities	'	'
Reserve for losses and loss expenses	9,667,841	9,582,140
Unearned premiums	3,372,166	2,683,849
Insurance and reinsurance balances payable	207,909	234,412
Senior notes	1,490,198	995,855
Payable for investments purchased	162,747	21,744
Other liabilities	218,502	248,822
Total liabilities	15,119,363	13,766,822
Shareholders' equity	'	'
Preferred shares	627,843	627,843
Common shares (2014: 175,195; 2013: 174,134 shares issued and 2014: 106,745; 2013: 109,485 shares outstanding)	2,188	2,174
Additional paid-in capital	2,247,102	2,240,125
Accumulated other comprehensive income	182,254	117,825
Retained earnings	5,170,948	5,062,706
Treasury shares, at cost (2014: 68,450; 2013: 64,649 shares)	-2,403,286	-2,232,711
Total shareholders' equity attributable to AXIS Capital	5,827,049	5,817,962
Noncontrolling interests	51,222	50,000
Total shareholders' equity	5,878,271	5,867,962
Total liabilities and shareholders' equity	$20,997,634	$19,634,784

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Fixed maturities, available for sale, amortized cost	$12,023,304	$11,987,146
Equity securities, available for sale, cost	581,473	566,219
Short term investments, amortized cost	$296,800	$46,212
Common shares, shares issued	175,195	174,134
Common shares, shares outstanding	106,745	109,485
Treasury shares, shares	68,450	64,649

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues	'	'
Net premiums earned	$945,949	$874,039
Net investment income	82,744	108,908
Other insurance related income	3,082	595
Net realized investment gains:	'	'
Other-than-temporary impairment (OTTI) losses	-786	-898
Non-credit portion of OTTI losses recognized in other comprehensive income	0	0
Other realized investment gains	11,406	45,376
Total net realized investment gains	10,620	44,478
Total revenues	1,042,395	1,028,020
Expenses	'	'
Net losses and loss expenses	544,207	438,414
Acquisition costs	172,036	145,491
General and administrative expenses	152,729	141,475
Foreign exchange losses (gains)	4,233	-34,882
Interest expense and financing costs	16,594	15,834
Total expenses	889,799	706,332
Income before income taxes	152,596	321,688
Income tax expense	4,125	10,131
Net income	148,471	311,557
Net income attributable to noncontrolling interests	1,222	0
Net income attributable to AXIS Capital	147,249	311,557
Preferred share dividends	10,022	8,741
Net income available to common shareholders	$137,227	$302,816
Net income per common share:	'	'
Basic net income	$1.26	$2.59
Diluted net income	$1.24	$2.55
Weighted average number of common shares outstanding - basic	109,053	117,022
Weighted average number of common shares outstanding - diluted	110,391	118,658
Cash dividends declared per common share	$0.27	$0.25

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]	'	'
Net income	$148,471	$311,557
Other comprehensive income (loss), net of tax:	'	'
Unrealized gains (losses) arising during the period	71,383	-18,525
Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	-9,613	-33,848
Unrealized gains (losses) arising during the period, net of reclassification adjustment	61,770	-52,373
Non-credit portion of OTTI losses	0	0
Foreign currency translation adjustment	2,659	-141
Total other comprehensive income (loss), net of tax	64,429	-52,514
Comprehensive income	$212,900	$259,043

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (USD $)	Total	Parent [Member]	Preferred shares [Member]	Common shares (par value) [Member]	Additional paid-in capital [Member]	Unrealized appreciation on available for sale investments, net of tax [Member]	Cumulative foreign currency translation adjustments, net of tax [Member]	Accumulated other comprehensive income [Member]	Retained earnings [Member]	Treasury shares, at cost [Member]	Noncontrolling interest [Member]
In Thousands
Total shareholders' equity at Dec. 31, 2012	'	'	$502,843	$2,146	$2,179,034	$348,328	$14,294	$362,622	$4,497,789	($1,764,673)	'
Shares issued	'	'	'	22	1,416	'	'	'	'	'	'
Cost of treasury shares reissued	'	'	'	'	0	'	'	'	'	0	'
Stock options exercised	'	'	'	'	5,919	'	'	'	'	'	'
Share-based compensation expense	'	'	'	'	12,723	'	'	'	'	'	'
Unrealized gains (losses) arising during the period, net of reclassification adjustment	-52,373	'	'	'	'	-52,373	'	'	'	'	'
Non-credit portion of OTTI losses	0	'	'	'	'	0	'	'	'	'	'
Foreign currency translation adjustments	-141	'	'	'	'	'	-141	'	'	'	'
Net income	311,557	'	'	'	'	'	'	'	311,557	'	'
Net income attributable to noncontrolling interests	0	'	'	'	'	'	'	'	0	'	'
Preferred share dividends	'	'	'	'	'	'	'	'	-8,741	'	'
Common share dividends	'	'	'	'	'	'	'	'	-30,841	'	'
Shares repurchased for treasury	'	'	'	'	'	'	'	'	'	-129,872	'
Total shareholders' equity at Mar. 31, 2013	5,889,430	5,889,430	502,843	2,168	2,199,092	295,955	14,153	310,108	4,769,764	-1,894,545	0
Total shareholders' equity at Dec. 31, 2013	5,867,962	'	627,843	2,174	2,240,125	124,945	-7,120	117,825	5,062,706	-2,232,711	'
Shares issued	'	'	'	14	1,861	'	'	'	'	'	'
Cost of treasury shares reissued	'	'	'	'	-8,128	'	'	'	'	8,128	'
Stock options exercised	'	'	'	'	392	'	'	'	'	'	'
Share-based compensation expense	'	'	'	'	12,852	'	'	'	'	'	'
Unrealized gains (losses) arising during the period, net of reclassification adjustment	61,770	'	'	'	'	61,770	'	'	'	'	'
Non-credit portion of OTTI losses	0	'	'	'	'	0	'	'	'	'	'
Foreign currency translation adjustments	2,659	'	'	'	'	'	2,659	'	'	'	'
Net income	148,471	'	'	'	'	'	'	'	148,471	'	'
Net income attributable to noncontrolling interests	-1,222	'	'	'	'	'	'	'	-1,222	'	'
Preferred share dividends	'	'	'	'	'	'	'	'	-10,022	'	'
Common share dividends	'	'	'	'	'	'	'	'	-28,985	'	'
Shares repurchased for treasury	'	'	'	'	'	'	'	'	'	-178,703	'
Total shareholders' equity at Mar. 31, 2014	$5,878,271	$5,827,049	$627,843	$2,188	$2,247,102	$186,715	($4,461)	$182,254	$5,170,948	($2,403,286)	$51,222

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:	'	'
Net income	$148,471	$311,557
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Net realized investment gains	-10,620	-44,478
Net realized and unrealized gains on other investments	-16,759	-43,431
Amortization of fixed maturities	30,919	38,677
Other amortization and depreciation	15,889	6,208
Share-based compensation expense, net of cash payments	8,700	14,012
Changes in:	'	'
Accrued interest receivable	7,626	1,343
Reinsurance recoverable balances	18,305	-31,728
Deferred acquisition costs	-178,170	-172,169
Prepaid reinsurance premiums	31,308	15,059
Reserve for loss and loss expenses	85,312	38,972
Unearned premiums	685,778	680,918
Insurance and reinsurance balances, net	-630,861	-603,478
Other items	-44,630	9,129
Net cash provided by operating activities	151,268	220,591
Cash flows from investing activities:	'	'
Fixed maturities	-3,298,375	-2,595,964
Equity securities	-73,197	-70,838
Other investments	-19,850	-107,436
Short-term investments	-420,115	-57,405
Proceeds from the sale of:	'	'
Fixed maturities	3,092,006	2,194,339
Equity securities	73,694	155,357
Other investments	76,657	21,941
Short-term investments	154,603	55,914
Proceeds from redemption of fixed maturities	279,815	357,915
Proceeds from redemption of short-term investments	14,548	10,955
Purchase of other assets	-19,152	-7,605
Change in restricted cash and cash equivalents	-24,405	34,174
Net cash used in investing activities	-163,771	-8,653
Cash flows from financing activities:	'	'
Net proceeds from issuance of senior notes	494,344	0
Repurchase of common shares	-162,536	-130,768
Dividends paid - common shares	-29,562	-33,189
Dividends paid - preferred shares	-10,022	-8,741
Proceeds from issuance of common shares	2,266	8,253
Net cash provided by (used in) financing activities	294,490	-164,445
Effect of exchange rate changes on foreign currency cash and cash equivalents	441	-7,654
Increase in cash and cash equivalents	282,428	39,839
Cash and cash equivalents - beginning of period	923,326	759,817
Cash and cash equivalents - end of period	$1,205,754	$799,656

BASIS_OF_PRESENTATION_AND_ACCO

BASIS OF PRESENTATION AND ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
BASIS OF PRESENTATION AND ACCOUNTING POLICIES [Text Block]	'
	Basis of Presentation
	These interim consolidated financial statements include the accounts of AXIS Capital Holdings Limited (“AXIS Capital”) and its subsidiaries (herein referred to as “we,” “us,” “our,” or the “Company”).
	The consolidated balance sheet at March 31, 2014 and the consolidated statements of operations, comprehensive income, shareholders' equity and cash flows for the periods ended March 31, 2014 and 2013 have not been audited. The balance sheet at December 31, 2013 is derived from our audited financial statements.
	These financial statements have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“U.S. GAAP”) for interim financial information and with the Securities and Exchange Commission's (“SEC”) instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, these financial statements reflect all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of our financial position and results of operations 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 following information should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2013. Tabular dollar and share amounts are in thousands, except per share amounts. All amounts are reported in U.S. dollars. To facilitate comparison of information across periods, certain reclassifications have been made to prior year amounts to conform to the current year's presentation.
	Significant Accounting Policies
	There were no notable changes in our significant accounting policies subsequent to our Annual Report on Form 10-K for the year ended December 31, 2013.

SEGMENT_INFORMATION

SEGMENT INFORMATION	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
SEGMENT INFORMATION [Text Block]	'
	Our underwriting operations are organized around our global underwriting platforms, AXIS Insurance and AXIS Re. Therefore we have determined that we have two reportable segments, insurance and reinsurance. We do not allocate our assets by segment, with the exception of goodwill and intangible assets, as we evaluate the underwriting results of each segment separately from the results of our investment portfolio.
	The following table summarizes the underwriting results of our reportable segments, as well as the carrying values of allocated goodwill and intangible assets:
			2014									2013
		Three months ended and at March 31,	Insurance			Reinsurance			Total			Insurance			Reinsurance			Total
		Gross premiums written	$	601,721		$	1,219,678		$	1,821,399		$	596,715		$	1,149,768		$	1,746,483
		Net premiums written	456,692			1,207,892			1,664,584			432,681			1,137,759			1,570,440
		Net premiums earned	449,214			496,735			945,949			401,880			472,159			874,039
		Other insurance related income	—			3,082			3,082			595			—			595
		Net losses and loss expenses	(279,423		)	(264,784		)	(544,207		)	(217,336		)	(221,078		)	(438,414		)
		Acquisition costs	(65,057		)	(106,979		)	(172,036		)	(57,261		)	(88,230		)	(145,491		)
		General and administrative expenses	(87,946		)	(36,076		)	(124,022		)	(86,889		)	(33,041		)	(119,930		)
		Underwriting income	$	16,788		$	91,978		108,766			$	40,989		$	129,810		170,799
		Corporate expenses							(28,707		)							(21,545		)
		Net investment income							82,744									108,908
		Net realized investment gains							10,620									44,478
		Foreign exchange (losses) gains							(4,233		)							34,882
		Interest expense and financing costs							(16,594		)							(15,834		)
		Income before income taxes							$	152,596								$	321,688
		Net loss and loss expense ratio	62.2		%	53.3		%	57.5		%	54.1		%	46.8		%	50.2		%
		Acquisition cost ratio	14.5		%	21.5		%	18.2		%	14.2		%	18.7		%	16.6		%
		General and administrative expense ratio	19.6		%	7.3		%	16.2		%	21.6		%	7		%	16.2		%
		Combined ratio	96.3		%	82.1		%	91.9		%	89.9		%	72.5		%	83		%
		Goodwill and intangible assets	$	90,350		$	—		$	90,350		$	97,001		$	—		$	97,001

INVESTMENTS

INVESTMENTS	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
INVESTMENTS [Text Block]	'
	a)     Fixed Maturities and Equities
	The amortized cost or cost and fair values of our fixed maturities and equities were as follows:
			Amortized			Gross				Gross			Fair			Non-credit
			Cost or			Unrealized				Unrealized			Value			OTTI
			Cost			Gains				Losses						in AOCI(5)
		At March 31, 2014
		Fixed maturities
		U.S. government and agency	$	1,705,581		$	2,686			$	(24,265	)	$	1,684,002		$	—
		Non-U.S. government	1,242,736			20,130				(33,060		)	1,229,806			—
		Corporate debt	3,757,948			84,688				(7,071		)	3,835,565			—
		Agency RMBS(1)	2,371,868			24,849				(31,959		)	2,364,758			—
		CMBS(2)	849,279			12,523				(2,207		)	859,595			—
		Non-Agency RMBS	95,261			4,682				(454		)	99,489			(863		)
		ABS(3)	968,942			4,057				(9,453		)	963,546			—
		Municipals(4)	1,031,689			32,627				(5,238		)	1,059,078			—
		Total fixed maturities	$	12,023,304		$	186,242			$	(113,707	)	$	12,095,839		$	(863	)
		Equity securities
		Common stocks	346,254			87,482				(5,502		)	428,234
		Exchange-traded funds	120,467			33,453				(61		)	153,859
		Non-U.S. bond mutual funds	114,752			11,567				—			126,319
		Total equity securities	$	581,473		$	132,502			$	(5,563	)	$	708,412
		At December 31, 2013
		Fixed maturities
		U.S. government and agency	$	1,421,245		$	1,405			$	(33,952	)	$	1,388,698		$	—
		Non-U.S. government	1,208,384			17,990				(49,992		)	1,176,382			—
		Corporate debt	3,533,585			84,881				(10,228		)	3,608,238			—
		Agency RMBS(1)	2,485,139			21,979				(58,291		)	2,448,827			—
		CMBS(2)	790,095			11,285				(3,966		)	797,414			—
		Non-Agency RMBS	65,590			2,375				(398		)	67,567			(868		)
		ABS(3)	955,274			6,871				(8,694		)	953,451			—
		Municipals(4)	1,527,834			32,432				(14,516		)	1,545,750			—
		Total fixed maturities	$	11,987,146		$	179,218			$	(180,037	)	$	11,986,327		$	(868	)
		Equity securities
		Common stocks	$	345,759		$	98,742			$	(6,183	)	$	438,318
		Exchange-traded funds	106,762			32,085				—			138,847
		Non-U.S. bond mutual funds	113,698			11,124				—			124,822
		Total equity securities	$	566,219		$	141,951			$	(6,183	)	$	701,987
	-1	Residential mortgage-backed securities (RMBS) originated by U.S. agencies.
	-2	Commercial mortgage-backed securities (CMBS).
	-3	Asset-backed securities (ABS) include debt tranched securities collateralized primarily by auto loans, student loans, credit cards, and other asset types. This asset class also includes collateralized loan obligations (CLOs) and collateralized debt obligations (CDOs).
	-4	Municipals include bonds issued by states, municipalities and political subdivisions.
	-5	Represents the non-credit component of the other-than-temporary impairment (OTTI) losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the impairment measurement date.
	In the normal course of investing activities, we actively manage allocations to non-controlling tranches of structured securities (variable interests) issued by VIEs. These structured securities include RMBS, CMBS and ABS and are included in the above table. Additionally, within our other investments portfolio, we also invest in limited partnerships (hedge funds) and CLO equity tranched securities, which are all variable interests issued by VIEs (see Note 3(b)). For these variable interests, we do not have the power to direct the activities that are most significant to the economic performance of the VIEs and accordingly we are not the primary beneficiary for any of these VIEs. Our maximum exposure to loss on these interests is limited to the amount of our investment. We have not provided financial or other support with respect to these structured securities other than our original investment.
	Contractual Maturities
	The contractual maturities of fixed maturities are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
			Amortized			Fair				% of Total
			Cost			Value				Fair Value
		At March 31, 2014
		Maturity
		Due in one year or less	$	541,871		$	547,897			4.5	%
		Due after one year through five years	5,204,615			5,288,307				43.7	%
		Due after five years through ten years	1,763,345			1,742,110				14.4	%
		Due after ten years	228,123			230,137				1.9	%
			7,737,954			7,808,451				64.5	%
		Agency RMBS	2,371,868			2,364,758				19.6	%
		CMBS	849,279			859,595				7.1	%
		Non-Agency RMBS	95,261			99,489				0.8	%
		ABS	968,942			963,546				8	%
		Total	$	12,023,304		$	12,095,839			100	%
		At December 31, 2013
		Maturity
		Due in one year or less	$	710,079		$	717,052			5.9	%
		Due after one year through five years	5,030,728			5,116,060				42.7	%
	Due after five years through ten years	1,852,877			1,791,835				14.9	%
	Due after ten years	97,364			94,121				0.8	%
		7,691,048			7,719,068				64.3	%
	Agency RMBS	2,485,139			2,448,827				20.4	%
	CMBS	790,095			797,414				6.7	%
	Non-Agency RMBS	65,590			67,567				0.6	%
	ABS	955,274			953,451				8	%
	Total	$	11,987,146		$	11,986,327			100	%
Gross Unrealized Losses
The following table summarizes fixed maturities and equities in an unrealized loss position and the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position:
		12 months or greater							Less than 12 months						Total
		Fair			Unrealized				Fair			Unrealized			Fair			Unrealized
		Value			Losses				Value			Losses			Value			Losses
	At March 31, 2014
	Fixed maturities
	U.S. government and agency	$	728		$	(15	)		$	1,063,725		$	(24,250	)	$	1,064,453		$	(24,265	)
	Non-U.S. government	22,848			(5,881		)		394,175			(27,179		)	417,023			(33,060		)
	Corporate debt	31,753			(640		)		633,852			(6,431		)	665,605			(7,071		)
	Agency RMBS	45,701			(1,740		)		1,400,738			(30,219		)	1,446,439			(31,959		)
	CMBS	12,170			(51		)		217,184			(2,156		)	229,354			(2,207		)
	Non-Agency RMBS	7,259			(361		)		15,606			(93		)	22,865			(454		)
	ABS	83,261			(3,575		)		526,622			(5,878		)	609,883			(9,453		)
	Municipals	6,978			(374		)		259,574			(4,864		)	266,552			(5,238		)
	Total fixed maturities	$	210,698		$	(12,637	)		$	4,511,476		$	(101,070	)	$	4,722,174		$	(113,707	)
	Equity securities
	Common stocks	$	3,629		$	(732	)		$	55,684		$	(4,770	)	$	59,313		$	(5,502	)
	Exchange-traded funds	—			—				13,202			(61		)	13,202			(61		)
	Total equity securities	$	3,629		$	(732	)		$	68,886		$	(4,831	)	$	72,515		$	(5,563	)
	At December 31, 2013
	Fixed maturities
	U.S. government and agency	$	—		$	—			$	982,307		$	(33,952	)	$	982,307		$	(33,952	)
	Non-U.S. government	35,577			(3,430		)		420,622			(46,562		)	456,199			(49,992		)
	Corporate debt	27,696			(802		)		606,592			(9,426		)	634,288			(10,228		)
	Agency RMBS	144,468			(5,247		)		1,478,527			(53,044		)	1,622,995			(58,291		)
	CMBS	13,319			(116		)		298,863			(3,850		)	312,182			(3,966		)
	Non-Agency RMBS	4,287			(315		)		5,319			(83		)	9,606			(398		)
	ABS	37,765			(2,941		)		553,803			(5,753		)	591,568			(8,694		)
	Municipals	8,408			(615		)		543,474			(13,901		)	551,882			(14,516		)
	Total fixed maturities	$	271,520		$	(13,466	)		$	4,889,507		$	(166,571	)	$	5,161,027		$	(180,037	)
	Equity securities
	Common stocks	$	3,499		$	(398	)		$	48,828		$	(5,785	)	$	52,327		$	(6,183	)
	Exchange-traded funds	—			—				—			—			—			—
	Total equity securities	$	3,499		$	(398	)		$	48,828		$	(5,785	)	$	52,327		$	(6,183	)
Fixed Maturities
At March 31, 2014, 989 fixed maturities (2013: 1,127) were in an unrealized loss position of $114 million (2013: $180 million), of which $1 million (2013: $2 million) was related to securities below investment grade or not rated.
At March 31, 2014, 95 (2013: 99) securities had been in a continuous unrealized loss position for 12 months or greater and had a fair value of $211 million (2013: $272 million). Following our credit impairment review, we concluded that these securities as well as the remaining securities in an unrealized loss position in the above table were temporarily impaired at March 31, 2014, and were expected to recover in value as the securities approach maturity. Further, at March 31, 2014, we did not intend to sell these securities in an unrealized loss position and it is more likely than not that we will not be required to sell these securities before the anticipated recovery of their amortized costs.
Equity Securities
At March 31, 2014, 66 securities (2013: 63) were in an unrealized loss position of $6 million (2013: $6 million).
At March 31, 2014, 11 (2013: 9) securities had been in a continuous unrealized loss position for 12 months or greater and had a fair value of $4 million (2013: $3 million). Based on our impairment review process and our ability and intent to hold these securities for a reasonable period of time sufficient for a full recovery, we concluded that the above equities in an unrealized loss position were temporarily impaired at March 31, 2014.
b) Other Investments
The following table provides a breakdown of our investments in hedge funds, direct lending funds and CLO Equities, together with additional information relating to the liquidity of each category:
		Fair Value						Redemption Frequency		Redemption
								(if currently eligible)		Notice Period
	At March 31, 2014
	Long/short equity funds	$	362,688		36	%		Monthly, Quarterly, Semi-annually		30-60 days
	Multi-strategy funds	295,485			29	%		Quarterly, Semi-annually		60-95 days
	Event-driven funds	184,342			18	%		Quarterly, Annually		45-60 days
	Leveraged bank loan funds	51,065			5	%		Quarterly		65 days
	Direct lending funds	26,003			3	%		n/a		n/a
	CLO - Equities	86,179			9	%		n/a		n/a
	Total other investments	$	1,005,762		100	%
	At December 31, 2013
	Long/short equity funds	$	425,444		41	%		Monthly, Quarterly, Semi-annually		30-60 days
	Multi-strategy funds	285,155			27	%		Quarterly, Semi-annually		60-95 days
	Event-driven funds	190,458			18	%		Quarterly, Annually		45-60 days
	Leveraged bank loan funds	48,753			5	%		Quarterly		65 days
	Direct lending funds	22,134			2	%		n/a		n/a
	CLO - Equities	73,866			7	%		n/a		n/a
	Total other investments	$	1,045,810		100	%
n/a - not applicable
The investment strategies for the above funds are as follows:
•	Long/short equity funds: Seek to achieve attractive returns by executing an equity trading strategy involving both long and short investments in publicly-traded equities.
•	Multi-strategy funds: Seek to achieve above-market returns by pursuing multiple investment strategies to diversify risks and reduce volatility. This category includes funds of hedge funds which invest in a large pool of hedge funds across a diversified range of hedge fund strategies.
•	Event-driven funds: Seek to achieve attractive returns by exploiting situations where announced or anticipated events create opportunities.
•	Leveraged bank loan funds: Seek to achieve attractive returns by investing primarily in bank loan collateral that has limited interest rate risk exposure.
•	Direct lending funds: Seek to achieve attractive risk-adjusted returns, including current income generation, by investing in funds which provide financing directly to borrowers.
Two common redemption restrictions which may impact our ability to redeem our hedge funds are gates and lockups. A gate is a suspension of redemptions which may be implemented by the general partner or investment manager of the fund in order to defer, in whole or in part, the redemption request in the event the aggregate amount of redemption requests exceeds a predetermined percentage of the fund's net assets which may otherwise hinder the general partner or investment manager's ability to liquidate holdings in an orderly fashion in order to generate the cash necessary to fund extraordinarily large redemption payouts. A lockup period is the initial amount of time an investor is contractually required to hold the security before having the ability to redeem. During 2014 and 2013, neither of these restrictions impacted our redemption requests. At March 31, 2014, $100 million (2013: $99 million), representing 11% (2013: 10%) of our total hedge funds, relate to holdings where we are still within the lockup period. The expiries of these lockup periods range from April 2014 to April 2016.
At March 31, 2014, $12 million (2013: $11 million) was invested in hedge funds that are not accepting redemption requests. Of this amount, substantially all relates to a leveraged bank loan fund in a period of planned principal distributions. Based on market conditions and payments made to date, management's current expectation is that the distribution process will be completed in 2014. The remainder primarily relates to funds that entered liquidation or had their assets side pocketed as a result of the global financial crisis which began in late 2008. For these funds, management is currently unable to estimate when those funds will be distributed.
At March 31, 2014, we have $84 million (2013: $88 million) of unfunded commitments within our other investments portfolio relating to our future investments in direct lending funds. Once the full amount of committed capital has been called by the General Partner of each of these funds, the assets will not be fully returned until the completion of the fund's investment term. These funds have investment terms ranging from 5-10 years and the General Partners of certain funds have the option to extend the term by up to three years.
During 2013, we made a $60 million commitment as a limited partner in a multi-strategy hedge fund. Once the full amount of committed capital has been called by the General Partner, the assets will not be fully returned until the completion of the fund's investment term which ends in December, 2018. The General Partner then has the option to extend the term by up to three years. At March 31, 2014, $50 million of our commitment remains unfunded and the current fair value of the funds called to date are included in the multi-strategy funds line of the table above.
During 2013, we made a $60 million commitment as a limited partner in a fund that invests primarily in CLO equities ("CLO fund").  We will not be eligible to redeem our investment until December, 2017 but expect to receive interest distributions on a quarterly basis.  At March 31, 2014, $13 million of our commitment remains unfunded and the current fair value of the funds called to date are included in the CLO - Equities line of the table above.  The CLO - Equities line also includes direct investment in the equity tranches of CLOs.
c) Net Investment Income
Net investment income was derived from the following sources:
		Three months ended March 31,
		2014			2013
	Fixed maturities	$	72,957		$	69,683
	Other investments	16,760			43,431
	Equity securities	2,286			1,414
	Cash and cash equivalents	863			1,267
	Short-term investments	214			532
	Gross investment income	93,080			116,327
	Investment expenses	(10,336		)	(7,419		)
	Net investment income	$	82,744		$	108,908
d) Net Realized Investment Gains
The following table provides an analysis of net realized investment gains:
		Three months ended March 31,
		2014			2013
	Gross realized gains
	Fixed maturities and short-term investments	$	33,770		$	32,864
	Equities	19,267			25,917
	Gross realized gains	53,037			58,781
	Gross realized losses
	Fixed maturities and short-term investments	(33,704		)	(17,274		)
	Equities	(2,438		)	(3,295		)
	Gross realized losses	(36,142		)	(20,569		)
	Net OTTI recognized in earnings	(786		)	(898		)
	Change in fair value of investment derivatives(1)	(5,489		)	7,164
	Net realized investment gains	$	10,620		$	44,478
(1) Refer to Note 5 – Derivative Instruments
The following table summarizes the OTTI recognized in earnings by asset class:
		Three months ended March 31,
		2014			2013
	Fixed maturities:
	Non-U.S. government	$	38		$	—
	Corporate debt	15			415
	ABS	56			129
		109			544
	Equity Securities
	Common stocks	677			354
		677			354
	Total OTTI recognized in earnings	$	786		$	898
The following table provides a roll forward of the credit losses, before income taxes, for which a portion of the OTTI was recognized in AOCI:
		Three months ended March 31,
		2014			2013
	Balance at beginning of period	$	1,594		$	1,809
	Credit impairments recognized on securities not previously impaired	—			—
	Additional credit impairments recognized on securities previously impaired	—			—
	Change in timing of future cash flows on securities previously impaired	—			—
	Intent to sell of securities previously impaired	—			—
	Securities sold/redeemed/matured	(4		)	(97		)
	Balance at end of period	$	1,590		$	1,712
e) Reverse Repurchase Agreements
At March 31, 2014, we held $97 million (2013: $34 million) of reverse repurchase agreements. These loans are fully collateralized, are generally outstanding for a short period of time and are presented on a gross basis as part of cash and cash equivalents on our consolidated balance sheet. The required collateral for these loans is either cash or U.S. Treasuries at a minimum rate of 102% of the loan principal. Upon maturity, we receive principal and interest income.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
FAIR VALUE MEASUREMENTS [Text Block]	'
	Fair Value Hierarchy
	Fair value is defined as the price to sell an asset or transfer a liability (i.e. the “exit price”) in an orderly transaction between market participants. We use a fair value hierarchy that gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data. The hierarchy is broken down into three levels as follows:
	•	Level 1 - Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access.
	•	Level 2 - Valuations based on quoted prices in active markets for similar assets or liabilities, quoted prices for identical assets or liabilities in inactive markets, or for which significant inputs are observable (e.g. interest rates, yield curves, prepayment speeds, default rates, loss severities, etc.) or can be corroborated by observable market data.
	•	Level 3 - Valuations based on inputs that are unobservable and significant to the overall fair value measurement. The unobservable inputs reflect our own judgments about assumptions that market participants might use.
	The availability of observable inputs can vary from financial instrument to financial instrument and is affected by a wide variety of factors including, for example, the type of financial instrument, whether the financial instrument is new and not yet established in the marketplace, and other characteristics particular to the transaction. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires significantly more judgment.
	Accordingly, the degree of judgment exercised by management in determining fair value is greatest for instruments categorized in Level 3. In periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This may lead us to change the selection of our valuation technique (from market to cash flow approach) or may cause us to use multiple valuation techniques to estimate the fair value of a financial instrument. This circumstance could cause an instrument to be reclassified between levels within the fair value hierarchy.
	We used the following valuation techniques and assumptions in estimating the fair value of our financial instruments as well as the general classification of such financial instruments pursuant to the above fair value hierarchy.
	Fixed Maturities
	At each valuation date, we use the market approach valuation technique to estimate the fair value of our fixed maturities portfolio, when possible. This market approach includes, but is not limited to, prices obtained from third party pricing services for identical or comparable securities and the use of “pricing matrix models” using observable market inputs such as yield curves, credit risks and spreads, measures of volatility, and prepayment speeds. Pricing from third party pricing services is sourced from multiple vendors, when available, and we maintain a vendor hierarchy by asset type based on historical pricing experience and vendor expertise. When prices are unavailable from pricing services, we obtain non-binding quotes from broker-dealers who are active in the corresponding markets.
	The following describes the significant inputs generally used to determine the fair value of our fixed maturities by asset class.
	U.S. government and agency
	U.S. government and agency securities consist primarily of bonds issued by the U.S. Treasury and mortgage pass-through agencies such as the Federal National Mortgage Association, the Federal Home Loan Mortgage Corporation and the Government National Mortgage Association. As the fair values of our U.S. Treasury securities are based on unadjusted market prices in active markets, they are classified within Level 1. The fair values of U.S. government agency securities are priced using the spread above the risk-free yield curve. As the yields for the risk-free yield curve and the spreads for these securities are observable market inputs, the fair values of U.S. government agency securities are classified within Level 2.
	Non-U.S. government
	Non-U.S. government securities comprise bonds issued by non-U.S. governments and their agencies along with supranational organizations (collectively also known as sovereign debt securities). The fair value of these securities is based on prices obtained from international indices or a valuation model that includes the following inputs: interest rate yield curves, cross-currency basis index spreads, and country credit spreads for structures similar to the sovereign bond in terms of issuer, maturity and seniority. As the significant inputs are observable market inputs, the fair value of non-U.S. government securities are classified within Level 2.
	Corporate debt
	Corporate debt securities consist primarily of investment-grade debt of a wide variety of corporate issuers and industries. The fair values of these securities are generally determined using the spread above the risk-free yield curve. These spreads are generally obtained from the new issue market, secondary trading and broker-dealer quotes. As these spreads and the yields for the risk-free yield curve are observable market inputs, the fair values of our corporate debt securities are classified within Level 2. Where pricing is unavailable from pricing services, we obtain non-binding quotes from broker-dealers to estimate fair value. This is generally the case when there is a low volume of trading activity and current transactions are not orderly. In this event, securities are classified within Level 3.
	MBS
	Our portfolio of RMBS and CMBS are originated by both agencies and non-agencies. The fair values of these securities are determined through the use of a pricing model (including Option Adjusted Spread) which uses prepayment speeds and spreads to determine the appropriate average life of the MBS. These spreads are generally obtained from the new issue market, secondary trading and broker-dealer quotes. As the significant inputs used to price MBS are observable market inputs, the fair values of the MBS are classified within Level 2. Where pricing is unavailable from pricing services, we obtain non-binding quotes from broker-dealers to estimate fair value. This is generally the case when there is a low volume of trading activity and current transactions are not orderly. These securities are classified within Level 3.
	ABS
	ABS include mostly investment-grade bonds backed by pools of loans with a variety of underlying collateral, including automobile loan receivables, student loans, credit card receivables, and CLO Debt originated by a variety of financial institutions. Similarly to MBS, the fair values of ABS are priced through the use of a model which uses prepayment speeds and spreads sourced primarily from the new issue market. As the significant inputs used to price ABS are observable market inputs, the fair values of ABS are classified within Level 2. Where pricing is unavailable from pricing services, we obtain non-binding quotes from broker-dealers or use a discounted cash flow model to estimate fair value. This is generally the case when there is a low volume of trading activity and current transactions are not orderly. These securities are priced within Level 3.
	Municipals
	Our municipal portfolio comprises revenue and general obligation bonds issued by U.S. domiciled state and municipal entities. The fair value of these securities is determined using spreads obtained from broker-dealers, trade prices and the new issue market. As the significant inputs used to price the municipals are observable market inputs, municipals are classified within Level 2.
	Equity Securities
	Equity securities include U.S. and non-U.S. common stocks, exchange-traded funds, and non-U.S. bond mutual funds. For common stocks and exchange-traded funds, we classified these within Level 1 as their fair values are based on unadjusted quoted market prices in active markets. Our investments in non-U.S. bond mutual funds have daily liquidity, with redemption based on the net asset value (NAV) of the funds. Accordingly, we have classified these investments as Level 2.
	Other Investments
	As a practical expedient, we estimate fair values for hedge funds, direct lending funds and the CLO fund using NAVs as advised by external fund managers or third party administrators. For each of these funds, the NAV is based on the manager's or administrator's valuation of the underlying holdings in accordance with the fund's governing documents and in accordance with U.S. GAAP. For any funds for which we have not yet received a NAV concurrent with our period end date, we record an estimate of the change in fair value for the period subsequent to the most recent NAV. Such estimates are based on return estimates for the period between the most recently issued NAV and the period end date; these estimates are obtained from the relevant fund managers. Accordingly, we do not typically have a reporting lag in our fair value measurements for these funds. Historically, our valuation estimates incorporating these return estimates have not significantly diverged from the subsequent NAVs.
	Within the hedge fund, direct lending fund and CLO fund industries, there is a general lack of transparency necessary to facilitate a detailed independent assessment of the values placed on the securities underlying the NAV provided by the fund manager or fund administrator. To address this, on a quarterly basis, we perform a number of monitoring procedures designed to assist us in the assessment of the quality of the information provided by managers and administrators. These procedures include, but are not limited to, regular review and discussion of each fund's performance with its manager, regular evaluation of fund performance against applicable benchmarks and the backtesting of our fair value estimates against subsequently received NAVs. Backtesting involves comparing our previously reported values for each individual fund against NAVs per audited financial statements (for year-end values) and final NAVs from fund managers and fund administrators (for interim values).
	For our hedge fund investments with liquidity terms allowing us to fully redeem our holdings at the applicable NAV in the near term, we have classified these investments as Level 2. Certain investments in hedge funds, all of our direct lending funds and our CLO fund have redemption restrictions (see Note 3(b) for further details) that prevent us from redeeming in the near term and therefore we have classified these investments as Level 3.
	At March 31, 2014, our direct investments in CLO - Equities were classified within Level 3 as we estimated the fair value for these securities using an income approach valuation technique (discounted cash flow model) due to the lack of observable and relevant trades in the secondary markets.
	Short-Term Investments
	Short-term investments primarily comprise highly liquid securities with maturities greater than three months but less than one year from the date of purchase. These securities are classified within Level 2 because these securities are typically not actively traded due to their approaching maturity and, as such, their amortized cost approximates fair value.
	Derivative Instruments
	Our foreign currency forward contracts and interest rate swaps are customized to our economic hedging strategies and trade in the over-the-counter derivative market. We use the market approach valuation technique to estimate the fair value for these derivatives based on significant observable market inputs from third party pricing vendors, non-binding broker-dealer quotes and/or recent trading activity. Accordingly, we classified these derivatives within Level 2.
	We also participate in non-exchange traded derivative-based risk management products addressing weather risks. We use observable market inputs and unobservable inputs in combination with industry or internally-developed valuation and forecasting techniques to determine fair value. We classify these instruments within Level 3.
	Cash Settled Awards
	Cash settled awards comprise restricted stock units that form part of our compensation program. Although the fair value of these awards is determined using observable quoted market prices in active markets, the stock units themselves are not actively traded. Accordingly, we have classified these liabilities within Level 2.
	The table below presents the financial instruments measured at fair value on a recurring basis:
			Quoted Prices in			Significant			Significant		Total Fair
			Active Markets for			Other Observable			Unobservable		Value
			Identical Assets			Inputs			Inputs
			(Level 1)			(Level 2)			(Level 3)
		At March 31, 2014
		Assets
		Fixed maturities
		U.S. government and agency	$	1,462,834		$	221,168		$	—	$	1,684,002
		Non-U.S. government	—			1,229,806			—		1,229,806
		Corporate debt	—			3,835,565			—		3,835,565
		Agency RMBS	—			2,364,758			—		2,364,758
		CMBS	—			855,626			3,969		859,595
		Non-Agency RMBS	—			99,489			—		99,489
		ABS	—			932,822			30,724		963,546
		Municipals	—			1,059,078			—		1,059,078
			1,462,834			10,598,312			34,693		12,095,839
		Equity securities
		Common stocks	428,234			—			—		428,234
		Exchange-traded funds	153,859			—			—		153,859
		Non-U.S. bond mutual funds	—			126,319			—		126,319
			582,093			126,319			—		708,412
		Other investments
		Hedge funds	—			428,914			464,666		893,580
		Direct lending funds	—			—			26,003		26,003
		CLO - Equities	—			—			86,179		86,179
		—			428,914			576,848		1,005,762
	Short-term investments	—			296,800			—		296,800
	Derivative instruments (see Note 5)	—			5,904			1,707		7,611
	Total Assets	$	2,044,927		$	11,456,249		$	613,248	$	14,114,424
	Liabilities
	Derivative instruments (see Note 5)	$	—		$	2,131		$	—	$	2,131
	Cash settled awards (see Note 7)	—			4,541			—		4,541
	Total Liabilities	$	—		$	6,672		$	—	$	6,672
	At December 31, 2013
	Assets
	Fixed maturities
	U.S. government and agency	$	1,119,632		$	269,066		$	—	$	1,388,698
	Non-U.S. government	—			1,176,382			—		1,176,382
	Corporate debt	—			3,608,238			—		3,608,238
	Agency RMBS	—			2,448,827			—		2,448,827
	CMBS	—			793,396			4,018		797,414
	Non-Agency RMBS	—			67,567			—		67,567
	ABS	—			922,652			30,799		953,451
	Municipals	—			1,545,750			—		1,545,750
		1,119,632			10,831,878			34,817		11,986,327
	Equity securities
	Common stocks	438,318			—			—		438,318
	Exchange-traded funds	138,847			—			—		138,847
	Non-U.S. bond mutual funds	—			124,822			—		124,822
		577,165			124,822			—		701,987
	Other investments
	Hedge funds	—			488,755			461,055		949,810
	Direct lending funds	—			—			22,134		22,134
	CLO - Equities	—			—			73,866		73,866
		—			488,755			557,055		1,045,810
	Short-term investments	—			46,212			—		46,212
	Derivative instruments (see Note 5)	—			6,824			984		7,808
	Total Assets	$	1,696,797		$	11,498,491		$	592,856	$	13,788,144
	Liabilities
	Derivative instruments (see Note 5)	$	—		$	1,152		$	815	$	1,967
	Cash settled awards (see Note 7)	—			8,693			—		8,693
	Total Liabilities	$	—		$	9,845		$	815	$	10,660
During 2014 and 2013, we had no transfers between Levels 1 and 2.
Level 3 Fair Value Measurements
Except for hedge funds, direct lending funds and our CLO fund priced using NAV as a practical expedient and certain fixed maturities priced using broker-dealer quotes (underlying inputs are not available), the following table quantifies the significant unobservable inputs we have used in estimating fair value at March 31, 2014 for our investments classified as Level 3 in the fair value hierarchy. These significant unobservable inputs have not changed significantly from December 31, 2013. Where appropriate, this table has been reconciled back to the asset class' total Level 3 holdings.
		Fair Value		Valuation Technique	Unobservable Input	Range	Weighted
							Average
	ABS - CLO Debt	$	29,911	Discounted cash flow	Credit spreads	3.6% - 4.4%	3.80%
					Illiquidity discount (1)	5.00%	5.00%
		813		Broker-dealer quote	n/a	n/a	n/a
		$	30,724
	Other investments - CLO - Equities	$	38,542	Discounted cash flow	Default rates	4.0% - 5.0%	4.30%
					Loss severity rate	53.50%	53.50%
					Collateral spreads	2.6% - 3.4%	3.30%
					Estimated maturity dates	3.4 - 4.5 years	4.1 years
		47,637		Net asset value	n/a	n/a	n/a
		$	86,179
	Derivatives - Weather derivatives, net	$	1,707	Simulation model	Weather curve	5,100(2)	n/a (3)
					Weather standard deviation	55(2)	n/a (3)
(1) Judgmentally determined based on limited trades of similar securities observed in the secondary markets.
(2) Measured in Heating Degree Days ("HDD") which is the number of degrees the daily temperature is below a reference temperature. The cumulative HDD for the duration of the derivatives contract is compared to the strike value to determine the necessary settlement.
-3	Due to the diversity of the portfolio, the range of unobservable inputs can be widespread; therefore, presentation of a weighted average is not useful. The current period reflects one open contract. Weather parameters may include various temperature and/or precipitation measures that will naturally vary by geographic location of each counterparty's operations.
Our CLO Debt represent holdings of investment-grade debt tranches within collateralized loan obligations with underlying collateral of loans originated primarily by U.S. corporations. The CLO Debt in the table represent securities where broker-dealer quotes are unavailable so we estimate fair value through the use of a discounted cash flow model (income approach). This model estimates fair values by discounting the estimated cash flows based on current credit spreads for similar securities, derived from observable offer prices. As these securities are thinly traded in the secondary market, we apply an illiquidity discount to these discounted cash flows in developing our estimate of fair value. Significant increases (decreases) in either of the significant unobservable inputs (credit spread, illiquidity discount) in isolation would result in lower (higher) fair value estimates for our CLO Debt. The interrelationship between these inputs is insignificant. These inputs are updated on a quarterly basis and the reasonableness of the resulting prices is assessed through a comparison to observable offer prices for similar securities.
The CLO - Equities market continues to be mostly inactive with only a small number of transactions being observed in the market and fewer still involving transactions in our CLO - Equities. Accordingly, we continue to rely on the use of our internal discounted cash flow model (income approach) to estimate fair value of our direct investments in CLO - Equities. Of the significant inputs into this model, the default and loss severity rates are the most judgmental unobservable market inputs to which the valuation of CLO - Equities is most sensitive. A significant increase (decrease) in either of these significant inputs in isolation would result in lower (higher) fair value estimates for direct investments in our CLO - Equities and, in general, a change in default rate assumptions will be accompanied by a directionally similar change in loss severity rate assumptions. Collateral spreads and estimated maturity dates are less judgmental inputs as they are based on the historical average of actual spreads and the weighted average life of the current underlying portfolios, respectively.  A significant increase (decrease) in either of these significant inputs in isolation would result in higher (lower) fair value estimates for direct investments in our CLO - Equities.  In general, these inputs have no significant interrelationship with each other or with default and loss severity rates.
On a quarterly basis, our valuation processes for both CLO Debt and CLO - Equities include a review of the underlying cash flows and key assumptions used in the discounted cash flow models. We review and update the above significant unobservable inputs based on information obtained from secondary markets, including from the managers of the CLOs we hold. These inputs are the responsibility of management and, in order to ensure fair value measurement is applied consistently and in accordance with U.S. GAAP, we update our assumptions through regular communication with industry participants and ongoing monitoring of the deals in which we participate (e.g. default and loss severity rate trends), we maintain a current understanding of the market conditions, historical results, as well as emerging trends that may impact future cash flows. By maintaining this current understanding, we are able to assess the reasonableness of the inputs we ultimately use in our models.
Weather derivatives relate to non-exchange traded risk management products addressing weather risks. We use observable market inputs and unobservable inputs in combination with industry or internally-developed simulation models to determine fair value; these models may reference market price information for similar instruments. The pricing models are internally reviewed by Risk Management personnel prior to implementation and are reviewed periodically thereafter.
Observable and unobservable inputs to these models vary by contract type and would typically include the following:
•	Observable inputs: market prices for similar instruments, notional, option strike, term to expiry, contractual limits;
•	Unobservable inputs: correlation; and
•	Both observable and unobservable inputs: weather curves, weather standard deviation.
In general, weather curves are the most significant contributing input to fair value determination; changes in this variable can result in result in higher or lower fair value depending on the underlying position. In addition, changes in any or all of the unobservable inputs identified above may contribute positively or negatively to overall portfolio value. The correlation input will quantify the interrelationship, if any, amongst the other variables.
The following tables present changes in Level 3 for financial instruments measured at fair value on a recurring basis for the periods indicated:
		Opening			Transfers			Transfers		Included in			Included			Purchases		Sales			Settlements/			Closing		Change in
		Balance			into			out of		earnings (1)			in OCI (2)								Distributions			Balance		unrealized
					Level 3			Level 3																		investment
																										gain/(loss) (3)
	Three months ended March 31, 2014
	Fixed maturities
	Corporate debt	$	—		$	—		$	—	$	—		$	—		$	—	$	—		$	—		$	—	$	—
	Non-Agency RMBS	—			—			—		—			—			—		—			—			—		—
	CMBS	4,018			—			—		—			(20		)	—		—			(29		)	3,969		—
	ABS	30,799			128			—		—			(95		)	—		—			(108		)	30,724		—
		34,817			128			—		—			(115		)	—		—			(137		)	34,693		—
	Other investments
	Hedge funds	461,055			—			—		8,177			—			4,500		—			(9,066		)	464,666		8,177
	Direct lending funds	22,134			—			—		552			—			3,445		—			(128		)	26,003		552
	CLO - Equities	73,866			—			—		6,150			—			12,845		—			(6,682		)	86,179		6,150
		557,055			—			—		14,879			—			20,790		—			(15,876		)	576,848		14,879
	Other assets
	Derivative instruments	984			—			—		4,718			—			—		—			(3,995		)	1,707		1,540
		984			—			—		4,718			—			—		—			(3,995		)	1,707		1,540
	Total assets	$	592,856		$	128		$	—	$	19,597		$	(115	)	$	20,790	$	—		$	(20,008	)	$	613,248	$	16,419
	Other liabilities
	Derivative instruments	815			—			—		986			—			—		—			(1,801		)	—		—
	Total liabilities	$	815		$	—		$	—	$	986		$	—		$	—	$	—		$	(1,801	)	$	—	$	—
		Opening			Transfers			Transfers		Included in			Included			Purchases		Sales			Settlements/			Closing		Change in
		Balance			into			out of		earnings (1)			in OCI (2)								Distributions			Balance		unrealized
					Level 3			Level 3																		investment
																										gain/loss  (3)
	Three months ended March 31, 2013
	Fixed maturities
	Corporate debt	$	1,550		$	—		$	—	$	1,550		$	—		$	—	$	(3,100	)	$	—		$	—	$	—
	Non-Agency RMBS	1,110			—			—		—			213			—		—			(23		)	1,300		—
	CMBS	4,296			8,382			—		—			(78		)	—		—			—			12,600		—
	ABS	63,975			—			—		(112		)	288			212,889		(10,190		)	(101		)	266,749		—
		70,931			8,382			—		1,438			423			212,889		(13,290		)	(124		)	280,649		—
	Other investments
	Hedge funds	359,996			—			—		18,528			—			52,436		—			(13,808		)	417,152		18,528
	Direct lending funds	—			—			—		—			—			—		—			—			—		—
	CLO - Equities	62,435			—			—		9,953			—			—		—			(8,133		)	64,255		9,953
		422,431			—			—		28,481			—			52,436		—			(21,941		)	481,407		28,481
	Other assets
	Derivative instruments	—			—			—		—			—			—		—			—			—		—
		—			—			—		—			—			—		—			—			—		—
	Total assets	$	493,362		$	8,382		$	—	$	29,919		$	423		$	265,325	$	(13,290	)	$	(22,065	)	$	762,056	$	28,481
	Other liabilities
	Derivative instruments	—			—			—		—			—			—		—			—			—		—
	Total liabilities	$	—		$	—		$	—	$	—		$	—		$	—	$	—		$	—		$	—	$	—
-1	Gains and losses included in earnings on fixed maturities are included in net realized investment gains (losses). Gains and (losses) included in earnings on other investments are included in net investment income. Gains (losses) on weather derivatives included in earnings are included in other insurance-related income.
-2	Gains and losses included in other comprehensive income (“OCI”) on fixed maturities are included in unrealized gains (losses) arising during the period.
-3	Change in unrealized investment gain/(loss) relating to assets held at the reporting date.
The transfers into and out of fair value hierarchy levels reflect the fair value of the securities at the end of the reporting period.
Transfers into Level 3 from Level 2
The transfers to Level 3 from Level 2 made during the three months ended March 31, 2014 and 2013 were primarily due to the lack of observable market inputs and multiple quotes from pricing vendors and broker-dealers for certain fixed maturities.
Transfers out of Level 3 into Level 2
There were no transfers to Level 2 from Level 3 made during the three months ended March 31, 2014 and 2013.
Financial Instruments Not Carried at Fair Value
U.S. GAAP guidance over disclosures about the fair value of financial instruments are also applicable to financial instruments not carried at fair value, except for certain financial instruments, including insurance contracts.
The carrying values of cash equivalents (including restricted amounts), accrued investment income, receivable for investments sold, certain other assets, payable for investments purchased and certain other liabilities approximated their fair values at March 31, 2014, due to their respective short maturities. As these financial instruments are not actively traded, their respective fair values are classified within Level 2.
At March 31, 2014, our senior notes are recorded at amortized cost with a carrying value of $1,490 million (2013: $996 million) and have a fair value of $1,568 million (2013: $1,073 million). The fair values of these securities were obtained from a third party pricing service and pricing was based on the spread above the risk-free yield curve. These spreads are generally obtained from the new issue market, secondary trading and broker-dealer quotes. As these spreads and the yields for the risk-free yield curve are observable market inputs, the fair values of our senior notes are classified within Level 2.

DERIVATIVE_INSTRUMENTS

DERIVATIVE INSTRUMENTS	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
DERIVATIVE INSTRUMENTS [Text Block]	'
	The following table summarizes the balance sheet classification of derivatives recorded at fair values. The notional amount of derivative contracts represents the basis upon which pay or receive amounts are calculated and is presented in the table to quantify the volume of our derivative activities. Notional amounts are not reflective of credit risk.
			March 31, 2014												December 31, 2013
			Derivative				Asset				Liability				Derivative				Asset		Liability
			Notional				Derivative				Derivative				Notional				Derivative		Derivative
			Amount				Fair				Fair				Amount				Fair		Fair
							Value(1)				Value(1)								Value(1)		Value(1)
		Derivatives not designated as hedging instruments
		Relating to investment portfolio:
		Foreign exchange forward contracts	$	329,121			$	78			$	2,060			$	254,023			$	1,214	$	1,032
		Interest rate swaps	281,250				145				71				281,250				873		—
		Relating to underwriting portfolio:
		Foreign exchange forward contracts	482,819				5,681				—				390,663				4,737		120
		Weather-related contracts	5,000				1,707				—				24,451				984		815
		Total derivatives					$	7,611			$	2,131							$	7,808	$	1,967
	-1	Asset and liability derivatives are classified within other assets and other liabilities on the Consolidated Balance Sheets.
	Offsetting Assets and Liabilities
	Our derivative instruments are generally traded under International Swaps and Derivatives Association master netting agreements, which establish terms that apply to all transactions. In the event of a bankruptcy or other stipulated event, master netting agreements provide that individual positions be replaced with a new amount, usually referred to as the termination amount, determined by taking into account market prices and converting into a single currency. Effectively, this contractual close-out netting reduces credit exposure from gross to net exposure. The table below presents a reconciliation of our gross derivative assets and liabilities to the net amounts presented in our Consolidated Balance Sheets, with the difference being attributable to the impact of master netting agreements.
			March 31, 2014										December 31, 2013
			Gross Amounts			Gross Amounts Offset			Net				Gross Amounts			Gross Amounts Offset			Net
									Amounts(1)										Amounts(1)
		Derivative assets	$	9,262		$	(1,651	)	$	7,611			$	9,796		$	(1,988	)	$	7,808
		Derivative liabilities	3,782			(1,651		)	2,131				3,955			(1,988		)	1,967
	-1	Net asset and liability derivatives are classified within other assets and other liabilities on the Consolidated Balance Sheets.
	Refer to Note 3 - Investments for information on reverse repurchase agreements.
	Derivative Instruments not Designated as Hedging Instruments
	a) Relating to Investment Portfolio
	Foreign Currency Risk
	Within our investment portfolio we are exposed to foreign currency risk. Accordingly, the fair values for our investment portfolio are partially influenced by the change in foreign exchange rates. We may enter into foreign exchange forward contracts to manage the effect of this currency risk. These foreign currency hedging activities are not designated as specific hedges for financial reporting purposes.
	In addition, our external equity investment managers have the discretion to hold foreign currency exposures as part of their total return strategy.
	The increase in the notional amount of investment-related derivatives since December 31, 2013 was due to an increase in Australian dollar-denominated fixed maturities being hedged.
	Interest Rate Risk
	Our investment portfolio contains a large percentage of fixed maturities which exposes us to significant interest rate risk. As part of our overall management of this risk, we may use interest rate swaps. The interest rate swaps held at March 31, 2014 convert part of our overall fixed rate exposure to a variable rate exposure which effectively reduces the duration of our overall portfolio.
	b) Relating to Underwriting Portfolio
	Foreign Currency Risk
	Our (re)insurance subsidiaries and branches operate in various foreign countries. Consequently, some of our business is written in currencies other than the U.S. dollar and, therefore, our underwriting portfolio is exposed to significant foreign currency risk. We manage foreign currency risk by seeking to match our foreign-denominated net liabilities under (re)insurance contracts with cash and investments that are denominated in such currencies. We may also use derivative instruments, specifically forward contracts and currency options, to economically hedge foreign currency exposures.
	The increase in the notional amount of underwriting related derivatives since December 31, 2013, was primarily due to new business written during the quarter.
	Weather Risk
	During 2013, we began to write derivative-based risk management products designed to address weather risks with the objective of generating profits on a portfolio basis. The majority of this business consists of receiving a payment at contract inception in exchange for bearing the risk of variations in a quantifiable weather-related phenomenon, such as temperature. Where a client wishes to minimize the upfront payment, these transactions may be structured as swaps or collars. In general, our portfolio of such derivative contracts is of short duration, with contracts being predominantly seasonal in nature. In order to economically hedge a portion of this portfolio, we may also purchase weather derivatives.
	The total unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges were as follows:
			Location of Gain (Loss) Recognized in Income on Derivative	Three months ended March 31,
				2014				2013
		Derivatives not designated as hedging instruments
		Relating to investment portfolio:
		Foreign exchange forward contracts	Net realized investment gains	$	(1,328	)		$	7,164
		Interest rate swaps	Net realized investment gains	(4,161		)		—
		Relating to underwriting portfolio:
		Foreign exchange forward contracts	Foreign exchange losses (gains)	12,074				2,488
		Weather-related contracts	Other insurance related income	3,678				—
		Total		$	10,263			$	9,652

RESERVE_FOR_LOSSES_AND_LOSS_EX

RESERVE FOR LOSSES AND LOSS EXPENSES	3 Months Ended
	Mar. 31, 2014
Insurance Loss Reserves [Abstract]	'
RESERVE FOR LOSSES AND LOSS EXPENSES [Text Block]	'
	The following table presents a reconciliation of our beginning and ending gross reserve for losses and loss expenses and net reserve for unpaid losses and loss expenses for the periods indicated:
		Three months ended March 31,	2014			2013
		Gross reserve for losses and loss expenses, beginning of period	$	9,582,140		$	9,058,731
		Less reinsurance recoverable on unpaid losses, beginning of period	(1,900,112		)	(1,825,617		)
		Net reserve for unpaid losses and loss expenses, beginning of period	7,682,028			7,233,114
		Net incurred losses and loss expenses related to:
		Current year	587,700			492,913
		Prior years	(43,493		)	(54,499		)
			544,207			438,414
		Net paid losses and loss expenses related to:
		Current year	(13,249		)	(10,846		)
		Prior years	(444,466		)	(358,964		)
			(457,715		)	(369,810		)
		Foreign exchange and other	14,501			(85,276		)
		Net reserve for unpaid losses and loss expenses, end of period	7,783,021			7,216,442
		Reinsurance recoverable on unpaid losses, end of period	1,884,820			1,881,261
		Gross reserve for losses and loss expenses, end of period	$	9,667,841		$	9,097,703
	Prior year reserve development arises from changes to loss and loss expense estimates recognized in the current year but relating to losses incurred in previous calendar years. Such development is summarized by segment in the following table:
			Three months ended March 31,
			2014			2013
		Insurance	$	11,608		$	5,598
		Reinsurance	31,885			48,901
		Total	$	43,493		$	54,499
	The majority of the net favorable prior year reserve development in each period related to short-tail lines of business. Net favorable prior year reserve development for liability reinsurance and professional lines reinsurance business also contributed in the three months ended March 31, 2014 and 2013.
	The underlying exposures in the property, marine and aviation reserving classes within our insurance segment and the property reserving class within our reinsurance segment largely relate to short-tail business. Development from these classes contributed $29 million and $30 million of the total net favorable prior year reserve development for the three months ended March 31, 2014 and 2013, respectively. The net favorable development for these classes primarily reflected the recognition of better than expected loss emergence.
	In the first quarter of 2013, we began to give weight to actuarial methods that reflect our actual experience for liability reinsurance business, as we believe that our older accident years are now at a stage of expected development where such methods will produce meaningful actuarial indications. For the three months ended March 31, 2014 and 2013, we recognized $6 million and $16 million, respectively, of net favorable prior year reserve development, primarily reflecting the greater weight management is giving to experience based indications and our experience which has been favorable for the 2004 through 2008 accident years.
	Our medium-tail business consists primarily of professional insurance and reinsurance lines and credit and surety reinsurance business. Our professional lines reinsurance business contributed further net favorable prior year reserve development of $6 million and $8 million in the three months ended March 31, 2014 and 2013, respectively. This prior year reserve development was driven by increased weight being given to experience based actuarial methods in selecting our ultimate loss estimates for accident years 2008 and prior. As our loss experience has generally been better than expected, this resulted in the recognition of favorable development.
	Our credit and surety line recorded favorable development of $10 million for the three months ended March 31, 2013 primarily driven by better than expected loss emergence related to the 2011 and 2012 accident years.
	The frequency and severity of natural catastrophe and weather activity was high in recent years and our March 31, 2014 net reserve for losses and loss expenses continues to include estimated amounts for numerous events. We caution that the magnitude and/or complexity of losses arising from certain of these events, in particular Storm Sandy, the 2011 Japanese earthquake and tsunami and 2010 and 2011 New Zealand earthquakes, inherently increase the level of uncertainty and, therefore, the level of management judgment involved in arriving at our estimated net reserves for losses and loss expenses. As a result, our actual losses for these events may ultimately differ materially from our current estimates.

SHAREBASED_COMPENSATION

SHARE-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
SHARE-BASED COMPENSATION [Text Block]	'
	For the three months ended March 31, 2014, we incurred share-based compensation costs of $17 million (2013: $14 million) and recorded associated tax benefits of $3 million (2013: $2 million).
	The fair value of shares vested during the three months ended March 31, 2014 was $61 million (2013: $59 million). At March 31, 2014 there were $168 million of unrecognized share-based compensation costs, which are expected to be recognized over the weighted average period of 2.8 years.
	Awards to settle in shares
	The following table provides a reconciliation of the beginning and ending balance of nonvested restricted stock (including restricted stock units) for the three months ended March 31, 2014:
			Performance-based Stock Awards			Service-based Stock Awards
			Number of	Weighted Average		Number of		Weighted Average
			Restricted	Grant Date		Restricted		Grant Date
			Stock	Fair Value		Stock		Fair Value
		Nonvested restricted stock - beginning of period	283	$	35.74	3,430		$	34.72
		Granted	68	44.33		988		44.34
		Vested	—	—		(1,230	)	33.68
		Forfeited	—	—		(60	)	35.41
		Nonvested restricted stock - end of period	351	$	37.41	3,128		$	38.03
	Cash-settled awards
	During 2014 we also granted 952,543 restricted stock units that will settle in cash rather than shares when the awards ultimately vest; of which 22,837 restricted stock units are performance based and 929,706 restricted stock units are service based. At March 31, 2014, the corresponding liability for cash-settled units, included in other liabilities on the Consolidated Balance Sheet, was $5 million (2013: $1 million).

EARNINGS_PER_COMMON_SHARE

EARNINGS PER COMMON SHARE	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
EARNINGS PER COMMON SHARE [Text Block]	'
	The following table sets forth the comparison of basic and diluted earnings per common share:
			Three months ended March 31,
			2014		2013
		Basic earnings per common share
		Net income	$	148,471	$	311,557
		Less: noncontrolling interests	1,222		—
		Less: preferred shares dividends	10,022		8,741
		Net income available to common shareholders	137,227		302,816
		Weighted average common shares outstanding - basic	109,053		117,022
		Basic earnings per common share	$	1.26	$	2.59
		Diluted earnings per common share
		Net income available to common shareholders	$	137,227	$	302,816
		Weighted average common shares outstanding - basic	109,053		117,022
		Stock compensation plans	1,338		1,636
		Weighted average common shares outstanding - diluted	110,391		118,658
		Diluted earnings per common share	$	1.24	$	2.55
		Anti-dilutive shares excluded from the dilutive computation	1,051		912

SHAREHOLDERS_EQUITY

SHAREHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2014
Stockholders' Equity Note [Abstract]	'
SHAREHOLDERS' EQUITY [Text Block]	'
	The following table presents our common shares issued and outstanding:
			Three months ended March 31,
			2014		2013
		Shares issued, balance at beginning of period	174,134		171,867
		Shares issued	1,061		1,728
		Total shares issued at end of period	175,195		173,595
		Treasury shares, balance at beginning of period	(64,649	)	(53,947	)
		Shares repurchased	(4,036	)	(3,369	)
		Shares reissued from treasury	235		27
		Total treasury shares at end of period	(68,450	)	(57,289	)
		Total shares outstanding	106,745		116,306
	Treasury Shares
	The following table presents our share repurchases:
			Three months ended March 31,
			2014			2013
		In the open market:
		Total shares	3,710			—
		Total cost	$	164,606		$	—
		Average price per share(1)	$	44.37		$	—
		From employees:
		Total shares	326			369
		Total cost	$	14,097		$	14,668
		Average price per share(1)	$	43.14		$	39.74
		From founding shareholder:(2)
		Total shares	—			3,000
		Total cost	$	—		$	116,100
		Average price per share(1)	$	—		$	38.7
		Total shares repurchased:
		Total shares	4,036			3,369
		Total cost	$	178,703		$	130,768
		Average price per share(1)	$	44.27		$	38.81
	-1	Calculated using whole figures.
	(2) During the first quarter of 2013, we privately negotiated the repurchase of 3,000,000 common shares held by Trident II, L.P. and affiliated entities.

NONCONTROLLING_INTEREST

NONCONTROLLING INTEREST	3 Months Ended
	Mar. 31, 2014
Noncontrolling Interest [Abstract]	'
Noncontrolling Interest Disclosure [Text Block]	'
	During November 2013, the Company formed AXIS Ventures Reinsurance Limited (Ventures Re), a Bermuda domiciled insurer. Ventures Re was formed to write reinsurance on a fully collateralized basis.
	In conjunction with the formation of Ventures Re, third party investors purchased $50 million of non-voting redeemable preferred share capital issued by this entity. The preferred shares are redeemable at the sole discretion of Ventures Re's Board of Directors, and are expected to be redeemed on or before July 1, 2016.
	Ventures Re is considered to be a variable interest entity. The Company has concluded that it is the primary beneficiary of Ventures Re as it has the power to direct, and has more than an insignificant economic interest in, the activities of this entity. Following this determination, Ventures Re was consolidated by the Company. Shareholders' equity attributable to Ventures Re's third party investors is recorded in the Consolidated Financial Statements as noncontrolling interests.
	At March 31, 2014, total assets of Ventures Re were $58 million (2013: $50 million), consisting primarily of cash and cash equivalents and insurance receivables. Total liabilities were $7 million (2013: $nil) primarily consisting of unearned premium. The assets of Ventures Re can only be used to settle its own liabilities, and there is no recourse to the Company for any liabilities incurred by this entity.
	The reconciliation of the beginning and ending balance of the noncontrolling interests in Ventures Re for the three months ended March 31, 2014 is as follows:
			Total
			2014
		Balance at January 1, 2014	$	50,000
		Net income attributable to noncontrolling interests	1,222
		Balance at March 31, 2014	$	51,222

DEBT_AND_FINANCING_ARRANGEMENT

DEBT AND FINANCING ARRANGEMENTS	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
DEBT AND FINANCING ARRANGEMENTS [Text Block]	'
	a)	Senior Notes
	On March 13, 2014, AXIS Specialty Finance PLC, a 100% owned finance subsidiary, issued $250 million aggregate principal amount of 2.65% senior unsecured notes (the "2.65% Senior Notes") at an issue price of 99.896% and $250 million aggregate principal amount of 5.15% senior unsecured notes (the "5.15% Senior Notes") at an issue price of 99.474%. The net proceeds of the issuance, after consideration of the offering discount and underwriting expenses and commissions, totaled approximately $248 million and $246 million for the 2.65% Senior Notes and the 5.15% Senior Notes, respectively. Interest on the 2.65% Senior Notes and the 5.15% Senior Notes is payable semi-annually in arrears on April 1 and October 1 of each year, beginning on October 1, 2014. Unless previously redeemed, the 2.65% Senior Notes and the 5.15% Senior Notes will mature on April 1, 2019 and April 1, 2045, respectively. The 2.65% Senior Notes and the 5.15% Senior Notes are ranked as unsecured senior obligations of AXIS Specialty Finance PLC. AXIS Capital has fully and unconditionally guaranteed all obligations of AXIS Specialty Finance PLC under the 2.65% Senior Notes and the 5.15% Senior Notes. AXIS Capital's obligations under this guarantee are unsecured and senior and rank equally with all other senior obligations of AXIS Capital. Net proceeds from this offering are expected to be used towards the repayment of $500 million of AXIS Capital’s 5.75% senior unsecured notes which mature on December 1, 2014.
	We have the option to redeem the 2.65% Senior Notes and the 5.15% Senior Notes at any time and from time to time, in whole or in part, at a “make-whole” redemption price, which is equal to the greater of the aggregate principal amount or the sum of the present values of the remaining scheduled payments of principal and interest. The related indentures contain various covenants, including limitations on liens on the stock of restricted subsidiaries, restrictions as to the disposition of the stock of restricted subsidiaries and limitations on mergers and consolidations. We were in compliance with all the covenants contained in the indentures at March 31, 2014.
	Interest expense recognized in relation to all of our senior unsecured notes includes interest payable, amortization of the offering discounts and amortization of debt offering expenses. The offering discounts and debt offering expenses are amortized over the period of time during which the underlying senior notes are outstanding. During the three months ended March 31, 2014, we incurred interest expense of $16 million (2013: $15 million) relating to all of our senior unsecured notes.
	b)	Credit Facilities
	Effective February 10, 2014, AXIS Specialty Finance PLC was added as a guarantor to our $250 million credit facility (the "Credit Facility").
	On March 31, 2014, AXIS Capital's subsidiary, AXIS Specialty Limited, terminated the $170 million secured letter of credit facility (the "Lloyd's LOC Facility") with ING Bank N.V., London Branch ("ING"). The Funds at Lloyd's requirements for the Company's subsidiary, AXIS Corporate Capital UK Limited, to support the underwriting capacity of the Company's Lloyd's syndicate, AXIS Syndicate 1686, are now being met by capital pledged in the form of fixed income securities deposited directly with Lloyd's.
	We are party to a $750 million letter of credit facility (the "LOC Facility") in addition to the Credit Facility. At March 31, 2014, letters of credit outstanding under the the LOC Facility and the Credit Facility totaled $462 million and nil, respectively. There was no debt outstanding under the Credit Facility.
	We were in compliance with all LOC Facility and Credit Facility covenants at March 31, 2014.

OTHER_COMPREHENSIVE_INCOME_LOS

OTHER COMPREHENSIVE INCOME (LOSS)	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
OTHER COMPREHENSIVE INCOME (LOSS) [Text Block]	'
	The tax effects allocated to each component of other comprehensive income (loss) were as follows:
			2014											2013
			Before Tax Amount				Tax (Expense) Benefit				Net of Tax Amount			Before Tax Amount			Tax (Expense) Benefit		Net of Tax Amount
		Three months ended March 31,
		Available for sale investments:
		Unrealized gains (losses) arising during the period	$	80,560			$	(9,177	)		$	71,383		$	(18,602	)	$	77	$	(18,525	)
		Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	(16,069		)		6,456				(9,613		)	(37,254		)	3,406		(33,848		)
		Unrealized gains (losses) arising during the period, net of reclassification adjustment	64,491				(2,721		)		61,770			(55,856		)	3,483		(52,373		)
		Non-credit portion of OTTI losses	—				—				—			—			—		—
		Foreign currency translation adjustment	2,659				—				2,659			(141		)	—		(141		)
		Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	—				—				—			—			—		—
		Total other comprehensive income (loss), net of tax	$	67,150			$	(2,721	)		$	64,429		$	(55,997	)	$	3,483	$	(52,514	)
	Reclassifications out of AOCI into net income available to common shareholders were as follows:
				Amount Reclassified from AOCI(1)
		Details About AOCI Components	Consolidated Statement of Operations Line Item That Includes Reclassification	Three months ended March 31,
				2014				2013
		Unrealized appreciation on available for sale investments
			Other realized investment gains	$	16,855			$	38,152
			OTTI losses	(786		)		(898		)
			Total before tax	16,069				37,254
			Tax expense	(6,456		)		(3,406		)
			Net of tax	$	9,613			$	33,848
	-1	Amounts in parentheses are debits to net income available to common shareholders.

BASIS_OF_PRESENTATION_AND_ACCO1

BASIS OF PRESENTATION AND ACCOUNTING POLICIES (POLICIES)	3 Months Ended
	Mar. 31, 2014
Policy Text Block [Abstract]	'
Basis of Presentation [Policy Text Block]	'
	These interim consolidated financial statements include the accounts of AXIS Capital Holdings Limited (“AXIS Capital”) and its subsidiaries (herein referred to as “we,” “us,” “our,” or the “Company”).
	The consolidated balance sheet at March 31, 2014 and the consolidated statements of operations, comprehensive income, shareholders' equity and cash flows for the periods ended March 31, 2014 and 2013 have not been audited. The balance sheet at December 31, 2013 is derived from our audited financial statements.
	These financial statements have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“U.S. GAAP”) for interim financial information and with the Securities and Exchange Commission's (“SEC”) instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, these financial statements reflect all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of our financial position and results of operations 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 following information should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2013. Tabular dollar and share amounts are in thousands, except per share amounts. All amounts are reported in U.S. dollars. To facilitate comparison of information across periods, certain reclassifications have been made to prior year amounts to conform to the current year's presentation.
	Significant Accounting Policies
	There were no notable changes in our significant accounting policies subsequent to our Annual Report on Form 10-K for the year ended December 31, 2013

SEGMENT_INFORMATION_TABLES

SEGMENT INFORMATION (TABLES)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
UNDERWRITING RESULTS OF REPORTABLE SEGMENTS [Table Text Block]	'
			2014									2013
		Three months ended and at March 31,	Insurance			Reinsurance			Total			Insurance			Reinsurance			Total
		Gross premiums written	$	601,721		$	1,219,678		$	1,821,399		$	596,715		$	1,149,768		$	1,746,483
		Net premiums written	456,692			1,207,892			1,664,584			432,681			1,137,759			1,570,440
		Net premiums earned	449,214			496,735			945,949			401,880			472,159			874,039
		Other insurance related income	—			3,082			3,082			595			—			595
		Net losses and loss expenses	(279,423		)	(264,784		)	(544,207		)	(217,336		)	(221,078		)	(438,414		)
		Acquisition costs	(65,057		)	(106,979		)	(172,036		)	(57,261		)	(88,230		)	(145,491		)
		General and administrative expenses	(87,946		)	(36,076		)	(124,022		)	(86,889		)	(33,041		)	(119,930		)
		Underwriting income	$	16,788		$	91,978		108,766			$	40,989		$	129,810		170,799
		Corporate expenses							(28,707		)							(21,545		)
		Net investment income							82,744									108,908
		Net realized investment gains							10,620									44,478
		Foreign exchange (losses) gains							(4,233		)							34,882
		Interest expense and financing costs							(16,594		)							(15,834		)
		Income before income taxes							$	152,596								$	321,688
		Net loss and loss expense ratio	62.2		%	53.3		%	57.5		%	54.1		%	46.8		%	50.2		%
		Acquisition cost ratio	14.5		%	21.5		%	18.2		%	14.2		%	18.7		%	16.6		%
		General and administrative expense ratio	19.6		%	7.3		%	16.2		%	21.6		%	7		%	16.2		%
		Combined ratio	96.3		%	82.1		%	91.9		%	89.9		%	72.5		%	83		%
		Goodwill and intangible assets	$	90,350		$	—		$	90,350		$	97,001		$	—		$	97,001

INVESTMENTS_TABLES

INVESTMENTS (TABLES)	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
AMORTIZED COST/COST AND FAIR VALUES OF FIXED MATURITIES AND EQUITIES [Table Text Block]	'
			Amortized			Gross				Gross			Fair			Non-credit
			Cost or			Unrealized				Unrealized			Value			OTTI
			Cost			Gains				Losses						in AOCI(5)
		At March 31, 2014
		Fixed maturities
		U.S. government and agency	$	1,705,581		$	2,686			$	(24,265	)	$	1,684,002		$	—
		Non-U.S. government	1,242,736			20,130				(33,060		)	1,229,806			—
		Corporate debt	3,757,948			84,688				(7,071		)	3,835,565			—
		Agency RMBS(1)	2,371,868			24,849				(31,959		)	2,364,758			—
		CMBS(2)	849,279			12,523				(2,207		)	859,595			—
		Non-Agency RMBS	95,261			4,682				(454		)	99,489			(863		)
		ABS(3)	968,942			4,057				(9,453		)	963,546			—
		Municipals(4)	1,031,689			32,627				(5,238		)	1,059,078			—
		Total fixed maturities	$	12,023,304		$	186,242			$	(113,707	)	$	12,095,839		$	(863	)
		Equity securities
		Common stocks	346,254			87,482				(5,502		)	428,234
		Exchange-traded funds	120,467			33,453				(61		)	153,859
		Non-U.S. bond mutual funds	114,752			11,567				—			126,319
		Total equity securities	$	581,473		$	132,502			$	(5,563	)	$	708,412
		At December 31, 2013
		Fixed maturities
		U.S. government and agency	$	1,421,245		$	1,405			$	(33,952	)	$	1,388,698		$	—
		Non-U.S. government	1,208,384			17,990				(49,992		)	1,176,382			—
		Corporate debt	3,533,585			84,881				(10,228		)	3,608,238			—
		Agency RMBS(1)	2,485,139			21,979				(58,291		)	2,448,827			—
		CMBS(2)	790,095			11,285				(3,966		)	797,414			—
		Non-Agency RMBS	65,590			2,375				(398		)	67,567			(868		)
		ABS(3)	955,274			6,871				(8,694		)	953,451			—
		Municipals(4)	1,527,834			32,432				(14,516		)	1,545,750			—
		Total fixed maturities	$	11,987,146		$	179,218			$	(180,037	)	$	11,986,327		$	(868	)
		Equity securities
		Common stocks	$	345,759		$	98,742			$	(6,183	)	$	438,318
		Exchange-traded funds	106,762			32,085				—			138,847
		Non-U.S. bond mutual funds	113,698			11,124				—			124,822
		Total equity securities	$	566,219		$	141,951			$	(6,183	)	$	701,987
	-1	Residential mortgage-backed securities (RMBS) originated by U.S. agencies.
	-2	Commercial mortgage-backed securities (CMBS).
	-3	Asset-backed securities (ABS) include debt tranched securities collateralized primarily by auto loans, student loans, credit cards, and other asset types. This asset class also includes collateralized loan obligations (CLOs) and collateralized debt obligations (CDOs).
	-4	Municipals include bonds issued by states, municipalities and political subdivisions.
	-5	Represents the non-credit component of the other-than-temporary impairment (OTTI) losses, adjusted for subsequent sales of securities. It does not include the change in fair value subsequent to the impairment measurement date.
CONTRACTUAL MATURITIES OF FIXED MATURITIES [Table Text Block]	'
			Amortized			Fair				% of Total
			Cost			Value				Fair Value
		At March 31, 2014
		Maturity
		Due in one year or less	$	541,871		$	547,897			4.5	%
		Due after one year through five years	5,204,615			5,288,307				43.7	%
		Due after five years through ten years	1,763,345			1,742,110				14.4	%
		Due after ten years	228,123			230,137				1.9	%
			7,737,954			7,808,451				64.5	%
		Agency RMBS	2,371,868			2,364,758				19.6	%
		CMBS	849,279			859,595				7.1	%
		Non-Agency RMBS	95,261			99,489				0.8	%
		ABS	968,942			963,546				8	%
		Total	$	12,023,304		$	12,095,839			100	%
		At December 31, 2013
		Maturity
		Due in one year or less	$	710,079		$	717,052			5.9	%
		Due after one year through five years	5,030,728			5,116,060				42.7	%
		Due after five years through ten years	1,852,877			1,791,835				14.9	%
		Due after ten years	97,364			94,121				0.8	%
			7,691,048			7,719,068				64.3	%
		Agency RMBS	2,485,139			2,448,827				20.4	%
		CMBS	790,095			797,414				6.7	%
		Non-Agency RMBS	65,590			67,567				0.6	%
		ABS	955,274			953,451				8	%
		Total	$	11,987,146		$	11,986,327			100	%
FIXED MATURITIES AND EQUITIES IN AN UNREALIZED LOSS POSITION [Table Text Block]	'
			12 months or greater							Less than 12 months						Total
			Fair			Unrealized				Fair			Unrealized			Fair			Unrealized
			Value			Losses				Value			Losses			Value			Losses
		At March 31, 2014
		Fixed maturities
		U.S. government and agency	$	728		$	(15	)		$	1,063,725		$	(24,250	)	$	1,064,453		$	(24,265	)
		Non-U.S. government	22,848			(5,881		)		394,175			(27,179		)	417,023			(33,060		)
		Corporate debt	31,753			(640		)		633,852			(6,431		)	665,605			(7,071		)
		Agency RMBS	45,701			(1,740		)		1,400,738			(30,219		)	1,446,439			(31,959		)
		CMBS	12,170			(51		)		217,184			(2,156		)	229,354			(2,207		)
		Non-Agency RMBS	7,259			(361		)		15,606			(93		)	22,865			(454		)
		ABS	83,261			(3,575		)		526,622			(5,878		)	609,883			(9,453		)
		Municipals	6,978			(374		)		259,574			(4,864		)	266,552			(5,238		)
		Total fixed maturities	$	210,698		$	(12,637	)		$	4,511,476		$	(101,070	)	$	4,722,174		$	(113,707	)
		Equity securities
		Common stocks	$	3,629		$	(732	)		$	55,684		$	(4,770	)	$	59,313		$	(5,502	)
		Exchange-traded funds	—			—				13,202			(61		)	13,202			(61		)
		Total equity securities	$	3,629		$	(732	)		$	68,886		$	(4,831	)	$	72,515		$	(5,563	)
		At December 31, 2013
		Fixed maturities
		U.S. government and agency	$	—		$	—			$	982,307		$	(33,952	)	$	982,307		$	(33,952	)
		Non-U.S. government	35,577			(3,430		)		420,622			(46,562		)	456,199			(49,992		)
		Corporate debt	27,696			(802		)		606,592			(9,426		)	634,288			(10,228		)
		Agency RMBS	144,468			(5,247		)		1,478,527			(53,044		)	1,622,995			(58,291		)
		CMBS	13,319			(116		)		298,863			(3,850		)	312,182			(3,966		)
		Non-Agency RMBS	4,287			(315		)		5,319			(83		)	9,606			(398		)
		ABS	37,765			(2,941		)		553,803			(5,753		)	591,568			(8,694		)
		Municipals	8,408			(615		)		543,474			(13,901		)	551,882			(14,516		)
		Total fixed maturities	$	271,520		$	(13,466	)		$	4,889,507		$	(166,571	)	$	5,161,027		$	(180,037	)
		Equity securities
		Common stocks	$	3,499		$	(398	)		$	48,828		$	(5,785	)	$	52,327		$	(6,183	)
		Exchange-traded funds	—			—				—			—			—			—
		Total equity securities	$	3,499		$	(398	)		$	48,828		$	(5,785	)	$	52,327		$	(6,183	)
PORTFOLIO OF OTHER INVESTMENTS [Table Text Block]	'
			Fair Value						Redemption Frequency		Redemption
									(if currently eligible)		Notice Period
		At March 31, 2014
		Long/short equity funds	$	362,688		36	%		Monthly, Quarterly, Semi-annually		30-60 days
		Multi-strategy funds	295,485			29	%		Quarterly, Semi-annually		60-95 days
		Event-driven funds	184,342			18	%		Quarterly, Annually		45-60 days
		Leveraged bank loan funds	51,065			5	%		Quarterly		65 days
		Direct lending funds	26,003			3	%		n/a		n/a
		CLO - Equities	86,179			9	%		n/a		n/a
		Total other investments	$	1,005,762		100	%
		At December 31, 2013
		Long/short equity funds	$	425,444		41	%		Monthly, Quarterly, Semi-annually		30-60 days
		Multi-strategy funds	285,155			27	%		Quarterly, Semi-annually		60-95 days
		Event-driven funds	190,458			18	%		Quarterly, Annually		45-60 days
		Leveraged bank loan funds	48,753			5	%		Quarterly		65 days
		Direct lending funds	22,134			2	%		n/a		n/a
		CLO - Equities	73,866			7	%		n/a		n/a
		Total other investments	$	1,045,810		100	%
	n/a - not applicable
NET INVESTMENT INCOME [Table Text Block]	'
			Three months ended March 31,
			2014			2013
		Fixed maturities	$	72,957		$	69,683
		Other investments	16,760			43,431
		Equity securities	2,286			1,414
		Cash and cash equivalents	863			1,267
		Short-term investments	214			532
		Gross investment income	93,080			116,327
		Investment expenses	(10,336		)	(7,419		)
		Net investment income	$	82,744		$	108,908
NET REALIZED INVESTMENT GAINS (LOSSES) [Table Text Block]	'
			Three months ended March 31,
			2014			2013
		Gross realized gains
		Fixed maturities and short-term investments	$	33,770		$	32,864
		Equities	19,267			25,917
		Gross realized gains	53,037			58,781
		Gross realized losses
		Fixed maturities and short-term investments	(33,704		)	(17,274		)
		Equities	(2,438		)	(3,295		)
		Gross realized losses	(36,142		)	(20,569		)
		Net OTTI recognized in earnings	(786		)	(898		)
		Change in fair value of investment derivatives(1)	(5,489		)	7,164
		Net realized investment gains	$	10,620		$	44,478
	(1) Refer to Note 5 – Derivative Instruments
OTTI RECOGNIZED IN EARNINGS BY ASSET CLASS [Table Text Block]	'
			Three months ended March 31,
			2014			2013
		Fixed maturities:
		Non-U.S. government	$	38		$	—
		Corporate debt	15			415
		ABS	56			129
			109			544
		Equity Securities
		Common stocks	677			354
			677			354
		Total OTTI recognized in earnings	$	786		$	898
ROLL FORWARD OF CREDIT LOSSES FOR WHICH A PORTION OF OTTI RECOGNIZED IN AOCI [Table Text Block]	'
			Three months ended March 31,
			2014			2013
		Balance at beginning of period	$	1,594		$	1,809
		Credit impairments recognized on securities not previously impaired	—			—
		Additional credit impairments recognized on securities previously impaired	—			—
		Change in timing of future cash flows on securities previously impaired	—			—
		Intent to sell of securities previously impaired	—			—
		Securities sold/redeemed/matured	(4		)	(97		)
		Balance at end of period	$	1,590		$	1,712

FAIR_VALUE_MEASUREMENTS_TABLES

FAIR VALUE MEASUREMENTS (TABLES)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
FINANCIAL INSTRUMENTS MEASURED AT FAIR VALUE ON A RECURRING BASIS [Table Text Block]	'
			Quoted Prices in			Significant			Significant		Total Fair
			Active Markets for			Other Observable			Unobservable		Value
			Identical Assets			Inputs			Inputs
			(Level 1)			(Level 2)			(Level 3)
		At March 31, 2014
		Assets
		Fixed maturities
		U.S. government and agency	$	1,462,834		$	221,168		$	—	$	1,684,002
		Non-U.S. government	—			1,229,806			—		1,229,806
		Corporate debt	—			3,835,565			—		3,835,565
		Agency RMBS	—			2,364,758			—		2,364,758
		CMBS	—			855,626			3,969		859,595
		Non-Agency RMBS	—			99,489			—		99,489
		ABS	—			932,822			30,724		963,546
		Municipals	—			1,059,078			—		1,059,078
			1,462,834			10,598,312			34,693		12,095,839
		Equity securities
		Common stocks	428,234			—			—		428,234
		Exchange-traded funds	153,859			—			—		153,859
		Non-U.S. bond mutual funds	—			126,319			—		126,319
			582,093			126,319			—		708,412
		Other investments
		Hedge funds	—			428,914			464,666		893,580
		Direct lending funds	—			—			26,003		26,003
		CLO - Equities	—			—			86,179		86,179
			—			428,914			576,848		1,005,762
		Short-term investments	—			296,800			—		296,800
		Derivative instruments (see Note 5)	—			5,904			1,707		7,611
		Total Assets	$	2,044,927		$	11,456,249		$	613,248	$	14,114,424
		Liabilities
		Derivative instruments (see Note 5)	$	—		$	2,131		$	—	$	2,131
		Cash settled awards (see Note 7)	—			4,541			—		4,541
		Total Liabilities	$	—		$	6,672		$	—	$	6,672
		At December 31, 2013
		Assets
		Fixed maturities
		U.S. government and agency	$	1,119,632		$	269,066		$	—	$	1,388,698
		Non-U.S. government	—			1,176,382			—		1,176,382
		Corporate debt	—			3,608,238			—		3,608,238
		Agency RMBS	—			2,448,827			—		2,448,827
		CMBS	—			793,396			4,018		797,414
		Non-Agency RMBS	—			67,567			—		67,567
		ABS	—			922,652			30,799		953,451
		Municipals	—			1,545,750			—		1,545,750
			1,119,632			10,831,878			34,817		11,986,327
		Equity securities
		Common stocks	438,318			—			—		438,318
		Exchange-traded funds	138,847			—			—		138,847
		Non-U.S. bond mutual funds	—			124,822			—		124,822
			577,165			124,822			—		701,987
		Other investments
		Hedge funds	—			488,755			461,055		949,810
		Direct lending funds	—			—			22,134		22,134
		CLO - Equities	—			—			73,866		73,866
			—			488,755			557,055		1,045,810
		Short-term investments	—			46,212			—		46,212
		Derivative instruments (see Note 5)	—			6,824			984		7,808
		Total Assets	$	1,696,797		$	11,498,491		$	592,856	$	13,788,144
		Liabilities
		Derivative instruments (see Note 5)	$	—		$	1,152		$	815	$	1,967
		Cash settled awards (see Note 7)	—			8,693			—		8,693
		Total Liabilities	$	—		$	9,845		$	815	$	10,660
LEVEL 3 FAIR VALUE MEASUREMENT INPUTS [Table Text Block]	'
			Fair Value		Valuation Technique	Unobservable Input	Range	Weighted
								Average
		ABS - CLO Debt	$	29,911	Discounted cash flow	Credit spreads	3.6% - 4.4%	3.80%
						Illiquidity discount (1)	5.00%	5.00%
			813		Broker-dealer quote	n/a	n/a	n/a
			$	30,724
		Other investments - CLO - Equities	$	38,542	Discounted cash flow	Default rates	4.0% - 5.0%	4.30%
						Loss severity rate	53.50%	53.50%
						Collateral spreads	2.6% - 3.4%	3.30%
						Estimated maturity dates	3.4 - 4.5 years	4.1 years
			47,637		Net asset value	n/a	n/a	n/a
			$	86,179
		Derivatives - Weather derivatives, net	$	1,707	Simulation model	Weather curve	5,100(2)	n/a (3)
						Weather standard deviation	55(2)	n/a (3)
	(1) Judgmentally determined based on limited trades of similar securities observed in the secondary markets.
	(2) Measured in Heating Degree Days ("HDD") which is the number of degrees the daily temperature is below a reference temperature. The cumulative HDD for the duration of the derivatives contract is compared to the strike value to determine the necessary settlement.
	-3	Due to the diversity of the portfolio, the range of unobservable inputs can be widespread; therefore, presentation of a weighted average is not useful. The current period reflects one open contract. Weather parameters may include various temperature and/or precipitation measures that will naturally vary by geographic location of each counterparty's operations.
CHANGES IN LEVEL 3 FINANCIAL INSTRUMENTS MEASURED AT FAIR VALUE ON A RECURRING BASIS [Table Text Block]	'
			Opening			Transfers			Transfers		Included in			Included			Purchases		Sales			Settlements/			Closing		Change in
			Balance			into			out of		earnings (1)			in OCI (2)								Distributions			Balance		unrealized
						Level 3			Level 3																		investment
																											gain/(loss) (3)
		Three months ended March 31, 2014
		Fixed maturities
		Corporate debt	$	—		$	—		$	—	$	—		$	—		$	—	$	—		$	—		$	—	$	—
		Non-Agency RMBS	—			—			—		—			—			—		—			—			—		—
		CMBS	4,018			—			—		—			(20		)	—		—			(29		)	3,969		—
		ABS	30,799			128			—		—			(95		)	—		—			(108		)	30,724		—
			34,817			128			—		—			(115		)	—		—			(137		)	34,693		—
		Other investments
		Hedge funds	461,055			—			—		8,177			—			4,500		—			(9,066		)	464,666		8,177
		Direct lending funds	22,134			—			—		552			—			3,445		—			(128		)	26,003		552
		CLO - Equities	73,866			—			—		6,150			—			12,845		—			(6,682		)	86,179		6,150
			557,055			—			—		14,879			—			20,790		—			(15,876		)	576,848		14,879
		Other assets
		Derivative instruments	984			—			—		4,718			—			—		—			(3,995		)	1,707		1,540
			984			—			—		4,718			—			—		—			(3,995		)	1,707		1,540
		Total assets	$	592,856		$	128		$	—	$	19,597		$	(115	)	$	20,790	$	—		$	(20,008	)	$	613,248	$	16,419
		Other liabilities
		Derivative instruments	815			—			—		986			—			—		—			(1,801		)	—		—
		Total liabilities	$	815		$	—		$	—	$	986		$	—		$	—	$	—		$	(1,801	)	$	—	$	—
			Opening			Transfers			Transfers		Included in			Included			Purchases		Sales			Settlements/			Closing		Change in
			Balance			into			out of		earnings (1)			in OCI (2)								Distributions			Balance		unrealized
						Level 3			Level 3																		investment
																											gain/loss  (3)
		Three months ended March 31, 2013
		Fixed maturities
		Corporate debt	$	1,550		$	—		$	—	$	1,550		$	—		$	—	$	(3,100	)	$	—		$	—	$	—
		Non-Agency RMBS	1,110			—			—		—			213			—		—			(23		)	1,300		—
		CMBS	4,296			8,382			—		—			(78		)	—		—			—			12,600		—
		ABS	63,975			—			—		(112		)	288			212,889		(10,190		)	(101		)	266,749		—
			70,931			8,382			—		1,438			423			212,889		(13,290		)	(124		)	280,649		—
		Other investments
		Hedge funds	359,996			—			—		18,528			—			52,436		—			(13,808		)	417,152		18,528
		Direct lending funds	—			—			—		—			—			—		—			—			—		—
		CLO - Equities	62,435			—			—		9,953			—			—		—			(8,133		)	64,255		9,953
			422,431			—			—		28,481			—			52,436		—			(21,941		)	481,407		28,481
		Other assets
		Derivative instruments	—			—			—		—			—			—		—			—			—		—
			—			—			—		—			—			—		—			—			—		—
		Total assets	$	493,362		$	8,382		$	—	$	29,919		$	423		$	265,325	$	(13,290	)	$	(22,065	)	$	762,056	$	28,481
		Other liabilities
		Derivative instruments	—			—			—		—			—			—		—			—			—		—
		Total liabilities	$	—		$	—		$	—	$	—		$	—		$	—	$	—		$	—		$	—	$	—
	-1	Gains and losses included in earnings on fixed maturities are included in net realized investment gains (losses). Gains and (losses) included in earnings on other investments are included in net investment income. Gains (losses) on weather derivatives included in earnings are included in other insurance-related income.
	-2	Gains and losses included in other comprehensive income (“OCI”) on fixed maturities are included in unrealized gains (losses) arising during the period.
	-3	Change in unrealized investment gain/(loss) relating to assets held at the reporting date.

DERIVATIVE_INSTRUMENTS_TABLES

DERIVATIVE INSTRUMENTS (TABLES)	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
LOCATION AND AMOUNTS OF DERIVATIVE FAIR VALUES ON THE CONSOLIDATED BALANCE SHEET [Table Text Block]	'
			March 31, 2014												December 31, 2013
			Derivative				Asset				Liability				Derivative				Asset		Liability
			Notional				Derivative				Derivative				Notional				Derivative		Derivative
			Amount				Fair				Fair				Amount				Fair		Fair
							Value(1)				Value(1)								Value(1)		Value(1)
		Derivatives not designated as hedging instruments
		Relating to investment portfolio:
		Foreign exchange forward contracts	$	329,121			$	78			$	2,060			$	254,023			$	1,214	$	1,032
		Interest rate swaps	281,250				145				71				281,250				873		—
		Relating to underwriting portfolio:
		Foreign exchange forward contracts	482,819				5,681				—				390,663				4,737		120
		Weather-related contracts	5,000				1,707				—				24,451				984		815
		Total derivatives					$	7,611			$	2,131							$	7,808	$	1,967
	-1	Asset and liability derivatives are classified within other assets and other liabilities on the Consolidated Balance Sheets.
RECONCILIATION OF GROSS DERIVATIVE ASSETS AND LIABILITIES TO NET AMOUNTS PRESENTED IN BALANCE SHEETS [Table Text Block]	'
			March 31, 2014										December 31, 2013
			Gross Amounts			Gross Amounts Offset			Net				Gross Amounts			Gross Amounts Offset			Net
									Amounts(1)										Amounts(1)
		Derivative assets	$	9,262		$	(1,651	)	$	7,611			$	9,796		$	(1,988	)	$	7,808
		Derivative liabilities	3,782			(1,651		)	2,131				3,955			(1,988		)	1,967
	-1	Net asset and liability derivatives are classified within other assets and other liabilities on the Consolidated Balance Sheets.
NET EARNINGS IMPACT OF FAIR VALUE HEDGES AND TOTAL UNREALIZED AND REALIZED GAINS (LOSSES) ON DERIVATIVES NOT DESIGNATED AS HEDGES RECORDED IN EARNINGS [Table Text Block]	'
			Location of Gain (Loss) Recognized in Income on Derivative	Three months ended March 31,
				2014				2013
		Derivatives not designated as hedging instruments
		Relating to investment portfolio:
		Foreign exchange forward contracts	Net realized investment gains	$	(1,328	)		$	7,164
		Interest rate swaps	Net realized investment gains	(4,161		)		—
		Relating to underwriting portfolio:
		Foreign exchange forward contracts	Foreign exchange losses (gains)	12,074				2,488
		Weather-related contracts	Other insurance related income	3,678				—
		Total		$	10,263			$	9,652

RESERVE_FOR_LOSSES_AND_LOSS_EX1

RESERVE FOR LOSSES AND LOSS EXPENSES (TABLES)	3 Months Ended
	Mar. 31, 2014
Insurance Loss Reserves [Abstract]	'
RECONCILIATION OF BEGINNING AND ENDING GROSS RESERVE FOR LOSSES AND LOSS EXPENSES AND NET RESERVE FOR UNPAID LOSSES AND LOSS EXPENSES [Table Text Block]	'
		Three months ended March 31,	2014			2013
		Gross reserve for losses and loss expenses, beginning of period	$	9,582,140		$	9,058,731
		Less reinsurance recoverable on unpaid losses, beginning of period	(1,900,112		)	(1,825,617		)
		Net reserve for unpaid losses and loss expenses, beginning of period	7,682,028			7,233,114
		Net incurred losses and loss expenses related to:
		Current year	587,700			492,913
		Prior years	(43,493		)	(54,499		)
			544,207			438,414
		Net paid losses and loss expenses related to:
		Current year	(13,249		)	(10,846		)
		Prior years	(444,466		)	(358,964		)
			(457,715		)	(369,810		)
		Foreign exchange and other	14,501			(85,276		)
		Net reserve for unpaid losses and loss expenses, end of period	7,783,021			7,216,442
		Reinsurance recoverable on unpaid losses, end of period	1,884,820			1,881,261
		Gross reserve for losses and loss expenses, end of period	$	9,667,841		$	9,097,703
NET PRIOR YEAR RESERVE DEVELOPMENT BY SEGMENT [Table Text Block]	'
			Three months ended March 31,
			2014			2013
		Insurance	$	11,608		$	5,598
		Reinsurance	31,885			48,901
		Total	$	43,493		$	54,499

SHAREBASED_COMPENSATION_TABLES

SHARE-BASED COMPENSATION (TABLES)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
RECONCILIATION OF BEGINNING AND ENDING BALANCE OF NONVESTED RESTRICTED STOCK (INCLUDING RSUS) TO BE SETTLED IN SHARES [Table Text Block]	'
			Performance-based Stock Awards			Service-based Stock Awards
			Number of	Weighted Average		Number of		Weighted Average
			Restricted	Grant Date		Restricted		Grant Date
			Stock	Fair Value		Stock		Fair Value
		Nonvested restricted stock - beginning of period	283	$	35.74	3,430		$	34.72
		Granted	68	44.33		988		44.34
		Vested	—	—		(1,230	)	33.68
		Forfeited	—	—		(60	)	35.41
		Nonvested restricted stock - end of period	351	$	37.41	3,128		$	38.03

EARNINGS_PER_COMMON_SHARE_TABL

EARNINGS PER COMMON SHARE (TABLES)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
BASIC AND DILUTED EARNINGS PER COMMON SHARE [Table Text Block]	'
			Three months ended March 31,
			2014		2013
		Basic earnings per common share
		Net income	$	148,471	$	311,557
		Less: noncontrolling interests	1,222		—
		Less: preferred shares dividends	10,022		8,741
		Net income available to common shareholders	137,227		302,816
		Weighted average common shares outstanding - basic	109,053		117,022
		Basic earnings per common share	$	1.26	$	2.59
		Diluted earnings per common share
		Net income available to common shareholders	$	137,227	$	302,816
		Weighted average common shares outstanding - basic	109,053		117,022
		Stock compensation plans	1,338		1,636
		Weighted average common shares outstanding - diluted	110,391		118,658
		Diluted earnings per common share	$	1.24	$	2.55
		Anti-dilutive shares excluded from the dilutive computation	1,051		912

SHAREHOLDERS_EQUITY_TABLES

SHAREHOLDERS' EQUITY (TABLES)	3 Months Ended
	Mar. 31, 2014
Stockholders' Equity Note [Abstract]	'
COMMON SHARES ISSUED AND OUTSTANDING [Table Text Block]	'
			Three months ended March 31,
			2014		2013
		Shares issued, balance at beginning of period	174,134		171,867
		Shares issued	1,061		1,728
		Total shares issued at end of period	175,195		173,595
		Treasury shares, balance at beginning of period	(64,649	)	(53,947	)
		Shares repurchased	(4,036	)	(3,369	)
		Shares reissued from treasury	235		27
		Total treasury shares at end of period	(68,450	)	(57,289	)
		Total shares outstanding	106,745		116,306
SHARE REPURCHASES [Table Text Block]	'
			Three months ended March 31,
			2014			2013
		In the open market:
		Total shares	3,710			—
		Total cost	$	164,606		$	—
		Average price per share(1)	$	44.37		$	—
		From employees:
		Total shares	326			369
		Total cost	$	14,097		$	14,668
		Average price per share(1)	$	43.14		$	39.74
		From founding shareholder:(2)
		Total shares	—			3,000
		Total cost	$	—		$	116,100
		Average price per share(1)	$	—		$	38.7
		Total shares repurchased:
		Total shares	4,036			3,369
		Total cost	$	178,703		$	130,768
		Average price per share(1)	$	44.27		$	38.81
	-1	Calculated using whole figures.
	(2) During the first quarter of 2013, we privately negotiated the repurchase of 3,000,000 common shares held by Trident II, L.P. and affiliated entities.

NONCONTROLLING_INTEREST_TABLES

NONCONTROLLING INTEREST (TABLES)	3 Months Ended
	Mar. 31, 2014
Noncontrolling Interest [Abstract]	'
RECONCILIATION OF BEGINNING AND ENDING BALANCES OF NONCONTROLLING INTEREST [Table Text Block]	'
			Total
			2014
		Balance at January 1, 2014	$	50,000
		Net income attributable to noncontrolling interests	1,222
		Balance at March 31, 2014	$	51,222

OTHER_COMPREHENSIVE_INCOME_LOS1

OTHER COMPREHENSIVE INCOME (LOSS) (TABLES)	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
TAX EFFECTS ALLOCATED TO EACH COMPONENT OF OTHER COMPREHENSIVE INCOME (LOSS) [Table Text Block]	'
			2014											2013
			Before Tax Amount				Tax (Expense) Benefit				Net of Tax Amount			Before Tax Amount			Tax (Expense) Benefit		Net of Tax Amount
		Three months ended March 31,
		Available for sale investments:
		Unrealized gains (losses) arising during the period	$	80,560			$	(9,177	)		$	71,383		$	(18,602	)	$	77	$	(18,525	)
		Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	(16,069		)		6,456				(9,613		)	(37,254		)	3,406		(33,848		)
		Unrealized gains (losses) arising during the period, net of reclassification adjustment	64,491				(2,721		)		61,770			(55,856		)	3,483		(52,373		)
		Non-credit portion of OTTI losses	—				—				—			—			—		—
		Foreign currency translation adjustment	2,659				—				2,659			(141		)	—		(141		)
		Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	—				—				—			—			—		—
		Total other comprehensive income (loss), net of tax	$	67,150			$	(2,721	)		$	64,429		$	(55,997	)	$	3,483	$	(52,514	)
RECLASSIFICATIONS OUT OF AOCI INTO NET INCOME AVAILABLE TO COMMON SHAREHOLDERS [Table Text Block]	'
				Amount Reclassified from AOCI(1)
		Details About AOCI Components	Consolidated Statement of Operations Line Item That Includes Reclassification	Three months ended March 31,
				2014				2013
		Unrealized appreciation on available for sale investments
			Other realized investment gains	$	16,855			$	38,152
			OTTI losses	(786		)		(898		)
			Total before tax	16,069				37,254
			Tax expense	(6,456		)		(3,406		)
			Net of tax	$	9,613			$	33,848
	-1	Amounts in parentheses are debits to net income available to common shareholders.

SEGMENT_INFORMATION_DETAILS

SEGMENT INFORMATION (DETAILS) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
	reportable_segment
Segment Information [Line Items]	'	'	'
Number of reportable segments	2	'	'
Net premiums earned	$945,949	$874,039	'
Other insurance related income	3,082	595	'
Net losses and loss expenses	-544,207	-438,414	'
Acquisition costs	-172,036	-145,491	'
General and administrative expenses	-152,729	-141,475	'
Net investment income	82,744	108,908	'
Net realized investment gains	10,620	44,478	'
Foreign exchange (losses) gains	-4,233	34,882	'
Interest expense and financing costs	-16,594	-15,834	'
Income before income taxes	152,596	321,688	'
Net loss and loss expense ratio	57.50%	50.20%	'
Acquisition cost ratio	18.20%	16.60%	'
General and administrative expense ratio	16.20%	16.20%	'
Combined ratio	91.90%	83.00%	'
Goodwill and intangible assets	90,350	97,001	89,528
Operating Segments [Member]	'	'	'
Segment Information [Line Items]	'	'	'
Gross premiums written	1,821,399	1,746,483	'
Net premiums written	1,664,584	1,570,440	'
Net premiums earned	945,949	874,039	'
Other insurance related income	3,082	595	'
Net losses and loss expenses	-544,207	-438,414	'
Acquisition costs	-172,036	-145,491	'
General and administrative expenses	-124,022	-119,930	'
Underwriting income	108,766	170,799	'
Operating Segments [Member] | Insurance [Member]	'	'	'
Segment Information [Line Items]	'	'	'
Gross premiums written	601,721	596,715	'
Net premiums written	456,692	432,681	'
Net premiums earned	449,214	401,880	'
Other insurance related income	0	595	'
Net losses and loss expenses	-279,423	-217,336	'
Acquisition costs	-65,057	-57,261	'
General and administrative expenses	-87,946	-86,889	'
Underwriting income	16,788	40,989	'
Net loss and loss expense ratio	62.20%	54.10%	'
Acquisition cost ratio	14.50%	14.20%	'
General and administrative expense ratio	19.60%	21.60%	'
Combined ratio	96.30%	89.90%	'
Goodwill and intangible assets	90,350	97,001	'
Operating Segments [Member] | Reinsurance [Member]	'	'	'
Segment Information [Line Items]	'	'	'
Gross premiums written	1,219,678	1,149,768	'
Net premiums written	1,207,892	1,137,759	'
Net premiums earned	496,735	472,159	'
Other insurance related income	3,082	0	'
Net losses and loss expenses	-264,784	-221,078	'
Acquisition costs	-106,979	-88,230	'
General and administrative expenses	-36,076	-33,041	'
Underwriting income	91,978	129,810	'
Net loss and loss expense ratio	53.30%	46.80%	'
Acquisition cost ratio	21.50%	18.70%	'
General and administrative expense ratio	7.30%	7.00%	'
Combined ratio	82.10%	72.50%	'
Goodwill and intangible assets	0	0	'
Corporate, Non-Segment [Member]	'	'	'
Segment Information [Line Items]	'	'	'
General and administrative expenses	-28,707	-21,545	'
Significant Reconciling Items [Member]	'	'	'
Segment Information [Line Items]	'	'	'
Net investment income	82,744	108,908	'
Net realized investment gains	10,620	44,478	'
Foreign exchange (losses) gains	-4,233	34,882	'
Interest expense and financing costs	($16,594)	($15,834)	'

INVESTMENTS_DETAILS

INVESTMENTS (DETAILS) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	$12,023,304	$11,987,146
Gross Unrealized Gains (fixed maturities)	186,242	179,218
Gross Unrealized Losses (fixed maturities)	-113,707	-180,037
Fair Value (fixed maturities)	12,095,839	11,986,327
Non-credit OTTI in AOCI	-863	-868
Cost	581,473	566,219
Gross Unrealized Gains (equities)	132,502	141,951
Gross Unrealized Losses (equities)	-5,563	-6,183
Fair Value (equities)	708,412	701,987
US Government and Agency [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	1,705,581	1,421,245
Gross Unrealized Gains (fixed maturities)	2,686	1,405
Gross Unrealized Losses (fixed maturities)	-24,265	-33,952
Fair Value (fixed maturities)	1,684,002	1,388,698
Non-credit OTTI in AOCI	0	0
Non-US Government [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	1,242,736	1,208,384
Gross Unrealized Gains (fixed maturities)	20,130	17,990
Gross Unrealized Losses (fixed maturities)	-33,060	-49,992
Fair Value (fixed maturities)	1,229,806	1,176,382
Non-credit OTTI in AOCI	0	0
Corporate Debt [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	3,757,948	3,533,585
Gross Unrealized Gains (fixed maturities)	84,688	84,881
Gross Unrealized Losses (fixed maturities)	-7,071	-10,228
Fair Value (fixed maturities)	3,835,565	3,608,238
Non-credit OTTI in AOCI	0	0
Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	2,371,868	2,485,139
Gross Unrealized Gains (fixed maturities)	24,849	21,979
Gross Unrealized Losses (fixed maturities)	-31,959	-58,291
Fair Value (fixed maturities)	2,364,758	2,448,827
Non-credit OTTI in AOCI	0	0
CMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	849,279	790,095
Gross Unrealized Gains (fixed maturities)	12,523	11,285
Gross Unrealized Losses (fixed maturities)	-2,207	-3,966
Fair Value (fixed maturities)	859,595	797,414
Non-credit OTTI in AOCI	0	0
Non-Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	95,261	65,590
Gross Unrealized Gains (fixed maturities)	4,682	2,375
Gross Unrealized Losses (fixed maturities)	-454	-398
Fair Value (fixed maturities)	99,489	67,567
Non-credit OTTI in AOCI	-863	-868
ABS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	968,942	955,274
Gross Unrealized Gains (fixed maturities)	4,057	6,871
Gross Unrealized Losses (fixed maturities)	-9,453	-8,694
Fair Value (fixed maturities)	963,546	953,451
Non-credit OTTI in AOCI	0	0
Municipals [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Amortized Cost	1,031,689	1,527,834
Gross Unrealized Gains (fixed maturities)	32,627	32,432
Gross Unrealized Losses (fixed maturities)	-5,238	-14,516
Fair Value (fixed maturities)	1,059,078	1,545,750
Non-credit OTTI in AOCI	0	0
Common Stock [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Cost	346,254	345,759
Gross Unrealized Gains (equities)	87,482	98,742
Gross Unrealized Losses (equities)	-5,502	-6,183
Fair Value (equities)	428,234	438,318
Exchange-Traded Funds [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Cost	120,467	106,762
Gross Unrealized Gains (equities)	33,453	32,085
Gross Unrealized Losses (equities)	-61	0
Fair Value (equities)	153,859	138,847
Non-U.S. Bond Mutual Funds [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Cost	114,752	113,698
Gross Unrealized Gains (equities)	11,567	11,124
Gross Unrealized Losses (equities)	0	0
Fair Value (equities)	$126,319	$124,822

INVESTMENTS_DETAILS_2

INVESTMENTS (DETAILS 2) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule Of Available For Sale Securities [Line Items]	'	'
Due in one year or less (amortized cost)	$541,871	$710,079
Due after one year through five years (amortized cost)	5,204,615	5,030,728
Due after five years through ten years (amortized cost)	1,763,345	1,852,877
Due after ten years (amortized cost)	228,123	97,364
Total fixed maturities with a single maturity date (amortized cost)	7,737,954	7,691,048
Total (amortized cost)	12,023,304	11,987,146
Due in one year or less (fair value)	547,897	717,052
Due after one year through five years (fair value)	5,288,307	5,116,060
Due after five years through ten years (fair value)	1,742,110	1,791,835
Due after ten years (fair value)	230,137	94,121
Total fixed maturities with a single maturity date (fair value)	7,808,451	7,719,068
Fair Value (fixed maturities)	12,095,839	11,986,327
Due in one year or less (% of total fair value)	4.50%	5.90%
Due after one year through five years (% of total fair value)	43.70%	42.70%
Due after five years through ten years (% of total fair value)	14.40%	14.90%
Due after ten years (% of total fair value)	1.90%	0.80%
Fixed maturities with a single maturity date (% of total fair value)	64.50%	64.30%
Total	100.00%	100.00%
Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fixed maturities without a single maturity date (amortized cost)	2,371,868	2,485,139
Total (amortized cost)	2,371,868	2,485,139
Fixed maturities without a single maturity date (fair value)	2,364,758	2,448,827
Fair Value (fixed maturities)	2,364,758	2,448,827
Fixed maturities without a single maturity date (% of total fair value)	19.60%	20.40%
CMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fixed maturities without a single maturity date (amortized cost)	849,279	790,095
Total (amortized cost)	849,279	790,095
Fixed maturities without a single maturity date (fair value)	859,595	797,414
Fair Value (fixed maturities)	859,595	797,414
Fixed maturities without a single maturity date (% of total fair value)	7.10%	6.70%
Non-Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fixed maturities without a single maturity date (amortized cost)	95,261	65,590
Total (amortized cost)	95,261	65,590
Fixed maturities without a single maturity date (fair value)	99,489	67,567
Fair Value (fixed maturities)	99,489	67,567
Fixed maturities without a single maturity date (% of total fair value)	0.80%	0.60%
ABS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fixed maturities without a single maturity date (amortized cost)	968,942	955,274
Total (amortized cost)	968,942	955,274
Fixed maturities without a single maturity date (fair value)	963,546	953,451
Fair Value (fixed maturities)	$963,546	$953,451
Fixed maturities without a single maturity date (% of total fair value)	8.00%	8.00%

INVESTMENTS_DETAILS_3

INVESTMENTS (DETAILS 3) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	security	security
Fixed Maturities [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	$210,698	$271,520
Unrealized Losses - 12 months or greater	-12,637	-13,466
Fair Value - Less than 12 months	4,511,476	4,889,507
Unrealized Losses - Less than 12 months	-101,070	-166,571
Total Fair Value of Securities in Unrealized Loss Position	4,722,174	5,161,027
Total Unrealized Losses	-113,707	-180,037
Number of Available For Sale Securities In Unrealized Loss Positions	989	1,127
Number of Available For Sale Securities in Unrealized Loss Positions for 12 Months or Greater	95	99
Fixed Maturities [Member] | Below Investment Grade or Not Rated [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Total Unrealized Losses	-1,000	-2,000
US Government and Agency [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	728	0
Unrealized Losses - 12 months or greater	-15	0
Fair Value - Less than 12 months	1,063,725	982,307
Unrealized Losses - Less than 12 months	-24,250	-33,952
Total Fair Value of Securities in Unrealized Loss Position	1,064,453	982,307
Total Unrealized Losses	-24,265	-33,952
Non-US Government [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	22,848	35,577
Unrealized Losses - 12 months or greater	-5,881	-3,430
Fair Value - Less than 12 months	394,175	420,622
Unrealized Losses - Less than 12 months	-27,179	-46,562
Total Fair Value of Securities in Unrealized Loss Position	417,023	456,199
Total Unrealized Losses	-33,060	-49,992
Corporate Debt [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	31,753	27,696
Unrealized Losses - 12 months or greater	-640	-802
Fair Value - Less than 12 months	633,852	606,592
Unrealized Losses - Less than 12 months	-6,431	-9,426
Total Fair Value of Securities in Unrealized Loss Position	665,605	634,288
Total Unrealized Losses	-7,071	-10,228
Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	45,701	144,468
Unrealized Losses - 12 months or greater	-1,740	-5,247
Fair Value - Less than 12 months	1,400,738	1,478,527
Unrealized Losses - Less than 12 months	-30,219	-53,044
Total Fair Value of Securities in Unrealized Loss Position	1,446,439	1,622,995
Total Unrealized Losses	-31,959	-58,291
CMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	12,170	13,319
Unrealized Losses - 12 months or greater	-51	-116
Fair Value - Less than 12 months	217,184	298,863
Unrealized Losses - Less than 12 months	-2,156	-3,850
Total Fair Value of Securities in Unrealized Loss Position	229,354	312,182
Total Unrealized Losses	-2,207	-3,966
Non-Agency RMBS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	7,259	4,287
Unrealized Losses - 12 months or greater	-361	-315
Fair Value - Less than 12 months	15,606	5,319
Unrealized Losses - Less than 12 months	-93	-83
Total Fair Value of Securities in Unrealized Loss Position	22,865	9,606
Total Unrealized Losses	-454	-398
ABS [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	83,261	37,765
Unrealized Losses - 12 months or greater	-3,575	-2,941
Fair Value - Less than 12 months	526,622	553,803
Unrealized Losses - Less than 12 months	-5,878	-5,753
Total Fair Value of Securities in Unrealized Loss Position	609,883	591,568
Total Unrealized Losses	-9,453	-8,694
Municipals [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	6,978	8,408
Unrealized Losses - 12 months or greater	-374	-615
Fair Value - Less than 12 months	259,574	543,474
Unrealized Losses - Less than 12 months	-4,864	-13,901
Total Fair Value of Securities in Unrealized Loss Position	266,552	551,882
Total Unrealized Losses	-5,238	-14,516
Equity Securities [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	3,629	3,499
Unrealized Losses - 12 months or greater	-732	-398
Fair Value - Less than 12 months	68,886	48,828
Unrealized Losses - Less than 12 months	-4,831	-5,785
Total Fair Value of Securities in Unrealized Loss Position	72,515	52,327
Total Unrealized Losses	-5,563	-6,183
Number of Available For Sale Securities In Unrealized Loss Positions	66	63
Number of Available For Sale Securities in Unrealized Loss Positions for 12 Months or Greater	11	9
Common Stock [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	3,629	3,499
Unrealized Losses - 12 months or greater	-732	-398
Fair Value - Less than 12 months	55,684	48,828
Unrealized Losses - Less than 12 months	-4,770	-5,785
Total Fair Value of Securities in Unrealized Loss Position	59,313	52,327
Total Unrealized Losses	-5,502	-6,183
Exchange-Traded Funds [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Fair Value - 12 months or greater	0	0
Unrealized Losses - 12 months or greater	0	0
Fair Value - Less than 12 months	13,202	0
Unrealized Losses - Less than 12 months	-61	0
Total Fair Value of Securities in Unrealized Loss Position	13,202	0
Total Unrealized Losses	($61)	$0

INVESTMENTS_DETAILS_4

INVESTMENTS (DETAILS 4) (USD $)

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Nov. 21, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Aug. 01, 2013

Hedge Funds [Member]

Hedge Funds [Member]

Hedge Funds [Member]

Hedge Funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Long/short equity funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Multi-strategy funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Event driven funds [Member]

Leveraged bank loan funds [Member]

Leveraged bank loan funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

Direct Lending Funds [Member]

CLO-Equities [Member]

CLO-Equities [Member]

CLO-Equities [Member]

CLO-Equities [Member]

Lockup Redemption Restriction [Member]

Lockup Redemption Restriction [Member]

Other Redemption Restriction [Member]

Other Redemption Restriction [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Other Redemption Restriction [Member]

Other Redemption Restriction [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Other Redemption Restriction [Member]

Other Redemption Restriction [Member]

Minimum [Member]

Maximum [Member]

Other Redemption Restriction [Member]

Other Redemption Restriction [Member]

Other Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other investments

$1,005,762,000

$1,045,810,000

'

'

'

'

$362,688,000

$425,444,000

'

'

'

'

$295,485,000

$285,155,000

'

'

'

'

'

'

$184,342,000

$190,458,000

'

'

'

'

$51,065,000

$48,753,000

$26,003,000

$22,134,000

'

'

'

'

$86,179,000

$73,866,000

'

'

Percentage of total fair value

100.00%

100.00%

'

'

'

'

36.00%

41.00%

'

'

'

'

29.00%

27.00%

'

'

'

'

'

'

18.00%

18.00%

'

'

'

'

5.00%

5.00%

3.00%

2.00%

'

'

'

'

9.00%

7.00%

'

'

Redemption frequency

'

'

'

'

'

'

'Monthly, Quarterly, Semi-annually

'Monthly, Quarterly, Semi-annually

'

'

'

'

'Quarterly, Semi-annually

'Quarterly, Semi-annually

'

'

'

'

'

'

'Quarterly, Annually

'Quarterly, Annually

'

'

'

'

'Quarterly

'Quarterly

'

'

'

'

'

'

'

'

'

'

Redemption notice period

'

'

'

'

'

'

'

'

'30 days

'30 days

'60 days

'60 days

'

'

'

'

'60 days

'60 days

'95 days

'95 days

'

'

'45 days

'45 days

'60 days

'60 days

'65 days

'65 days

'

'

'

'

'

'

'

'

'

'

Fair value of other investments subject to redemption restrictions

'

'

100,000,000

99,000,000

12,000,000

11,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

26,003,000

22,134,000

'

'

'

'

'

'

Percentage of fair value of other investments subject to redemption restrictions

'

'

11.00%

10.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.00%

2.00%

'

'

'

'

'

'

Unfunded commitments related to other investments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$50,000,000

$60,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$84,000,000

$88,000,000

'

'

'

'

$13,000,000

$60,000,000

Investment term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'10 years

'

'

'

'

Optional extension of investment term

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

INVESTMENTS_DETAILS_5

INVESTMENTS (DETAILS 5) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net Investment Income [Line Items]	'	'
Gross investment income	$93,080	$116,327
Investment expenses	-10,336	-7,419
Net investment income	82,744	108,908
Fixed Maturities [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	72,957	69,683
Other Investments [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	16,760	43,431
Equity Securities [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	2,286	1,414
Cash And Cash Equivalents [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	863	1,267
Short-term Investments [Member]	'	'
Net Investment Income [Line Items]	'	'
Gross investment income	$214	$532

INVESTMENTS_DETAILS_6

INVESTMENTS (DETAILS 6) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Schedule Of Available For Sale Securities [Line Items]	'	'
Gross realized gains	$53,037	$58,781
Gross realized losses	-36,142	-20,569
Net OTTI recognized in earnings	-786	-898
Change in fair value of investment derivatives	-5,489	7,164
Total net realized investment gains	10,620	44,478
Fixed Maturities And Short-Term Investments [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Gross realized gains	33,770	32,864
Gross realized losses	-33,704	-17,274
Equity Securities [Member]	'	'
Schedule Of Available For Sale Securities [Line Items]	'	'
Gross realized gains	19,267	25,917
Gross realized losses	($2,438)	($3,295)

INVESTMENTS_DETAILS_7

INVESTMENTS (DETAILS 7) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'
Total OTTI recognized in earnings	$786	$898
Fixed Maturities [Member]	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'
Total OTTI recognized in earnings	109	544
Non-US Government [Member]	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'
Total OTTI recognized in earnings	38	0
Corporate Debt [Member]	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'
Total OTTI recognized in earnings	15	415
ABS [Member]	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'
Total OTTI recognized in earnings	56	129
Equity Securities [Member]	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'
Total OTTI recognized in earnings	677	354
Common Stock [Member]	'	'
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net [Line Items]	'	'
Total OTTI recognized in earnings	$677	$354

INVESTMENTS_DETAILS_8

INVESTMENTS (DETAILS 8) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Credit Losses For Which a Portion of OTTI Was Recognized in AOCI [Roll Forward]	'	'
Balance at beginning of period	$1,594	$1,809
Credit impairments recognized on securities not previously impaired	0	0
Additional credit impairments recognized on securities previously impaired	0	0
Change in timing of future cash flows on securities previously impaired	0	0
Intent to sell of securities previously impaired	0	0
Securities sold/redeemed/matured	-4	-97
Balance at end of period	$1,590	$1,712

INVESTMENTS_DETAILS_9

INVESTMENTS (DETAILS 9) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]	'	'
Value of reverse repurchase agreements	$97	$34
Minimum required collateral for reverse repurchase agreements, expressed as a percentage of loan principal	102.00%	'

FAIR_VALUE_MEASUREMENTS_DETAIL

FAIR VALUE MEASUREMENTS (DETAILS) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	$12,095,839	$11,986,327
Equity securities	708,412	701,987
Other investments	1,005,762	1,045,810
Short-term investments	296,800	46,212
Derivative assets (see Note 5)	7,611	7,808
Derivative liabilities (see Note 5)	2,131	1,967
Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	12,095,839	11,986,327
Equity securities	708,412	701,987
Other investments	1,005,762	1,045,810
Short-term investments	296,800	46,212
Derivative assets (see Note 5)	7,611	7,808
Total assets	14,114,424	13,788,144
Derivative liabilities (see Note 5)	2,131	1,967
Cash settled awards (see Note 7)	4,541	8,693
Total liabilities	6,672	10,660
US Government and Agency [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,684,002	1,388,698
US Government and Agency [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,684,002	1,388,698
Non-US Government [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,229,806	1,176,382
Non-US Government [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,229,806	1,176,382
Corporate Debt [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,835,565	3,608,238
Corporate Debt [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,835,565	3,608,238
Agency RMBS [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	2,364,758	2,448,827
Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	2,364,758	2,448,827
CMBS [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	859,595	797,414
CMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	859,595	797,414
Non-Agency RMBS [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	99,489	67,567
Non-Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	99,489	67,567
ABS [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	963,546	953,451
ABS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	963,546	953,451
Municipals [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,059,078	1,545,750
Municipals [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,059,078	1,545,750
Common Stock [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	428,234	438,318
Common Stock [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	428,234	438,318
Exchange-Traded Funds [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	153,859	138,847
Exchange-Traded Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	153,859	138,847
Non-U.S. Bond Mutual Funds [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	126,319	124,822
Non-U.S. Bond Mutual Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	126,319	124,822
Hedge Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	893,580	949,810
Direct Lending Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	26,003	22,134
CLO-Equities [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	86,179	73,866
Level 1 [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,462,834	1,119,632
Equity securities	582,093	577,165
Other investments	0	0
Short-term investments	0	0
Derivative assets (see Note 5)	0	0
Total assets	2,044,927	1,696,797
Derivative liabilities (see Note 5)	0	0
Cash settled awards (see Note 7)	0	0
Total liabilities	0	0
Level 1 [Member] | US Government and Agency [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,462,834	1,119,632
Level 1 [Member] | Non-US Government [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Corporate Debt [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | CMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Non-Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | ABS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Municipals [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 1 [Member] | Common Stock [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	428,234	438,318
Level 1 [Member] | Exchange-Traded Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	153,859	138,847
Level 1 [Member] | Non-U.S. Bond Mutual Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 1 [Member] | Hedge Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 1 [Member] | Direct Lending Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 1 [Member] | CLO-Equities [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 2 [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	10,598,312	10,831,878
Equity securities	126,319	124,822
Other investments	428,914	488,755
Short-term investments	296,800	46,212
Derivative assets (see Note 5)	5,904	6,824
Total assets	11,456,249	11,498,491
Derivative liabilities (see Note 5)	2,131	1,152
Cash settled awards (see Note 7)	4,541	8,693
Total liabilities	6,672	9,845
Level 2 [Member] | US Government and Agency [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	221,168	269,066
Level 2 [Member] | Non-US Government [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,229,806	1,176,382
Level 2 [Member] | Corporate Debt [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,835,565	3,608,238
Level 2 [Member] | Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	2,364,758	2,448,827
Level 2 [Member] | CMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	855,626	793,396
Level 2 [Member] | Non-Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	99,489	67,567
Level 2 [Member] | ABS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	932,822	922,652
Level 2 [Member] | Municipals [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,059,078	1,545,750
Level 2 [Member] | Common Stock [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 2 [Member] | Exchange-Traded Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 2 [Member] | Non-U.S. Bond Mutual Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	126,319	124,822
Level 2 [Member] | Hedge Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	428,914	488,755
Level 2 [Member] | Direct Lending Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 2 [Member] | CLO-Equities [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	0	0
Level 3 [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	34,693	34,817
Equity securities	0	0
Other investments	576,848	557,055
Short-term investments	0	0
Derivative assets (see Note 5)	1,707	984
Total assets	613,248	592,856
Derivative liabilities (see Note 5)	0	815
Cash settled awards (see Note 7)	0	0
Total liabilities	0	815
Level 3 [Member] | US Government and Agency [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | Non-US Government [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | Corporate Debt [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | CMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,969	4,018
Level 3 [Member] | Non-Agency RMBS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | ABS [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	30,724	30,799
Level 3 [Member] | Municipals [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Fixed maturities	0	0
Level 3 [Member] | Common Stock [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 3 [Member] | Exchange-Traded Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 3 [Member] | Non-U.S. Bond Mutual Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Equity securities	0	0
Level 3 [Member] | Hedge Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	464,666	461,055
Level 3 [Member] | Direct Lending Funds [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	26,003	22,134
Level 3 [Member] | CLO-Equities [Member] | Fair Value Measurements Recurring [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Other investments	$86,179	$73,866

FAIR_VALUE_MEASUREMENTS_DETAIL1

FAIR VALUE MEASUREMENTS (DETAILS 2) (USD $)

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

In Thousands, unless otherwise specified

Level 3 [Member]

Level 3 [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Broker-dealer quote [Member]

Net asset value [Member]

Simulation model [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Weighted Average [Member]

Weighted Average [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

Discounted cash flow [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

Weather Related Derivative [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

ABS - CLO Debt [Member]

Other Investments - CLO-Equities [Member]

Fair Value Inputs Assets Quantitative Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fixed maturities

$12,095,839

$11,986,327

$30,724

'

$29,911

'

$813

'

'

'

'

'

'

'

'

Other investments

1,005,762

1,045,810

'

86,179

'

38,542

'

47,637

'

'

'

'

'

'

'

Net derivative assets

'

'

'

'

'

'

'

'

$1,707

'

'

'

'

'

'

Credit spread

'

'

'

'

'

'

'

'

'

3.60%

'

4.40%

'

3.80%

'

Illiquidity discount

'

'

'

'

5.00%

'

'

'

'

'

'

'

'

5.00%

'

Default rates

'

'

'

'

'

'

'

'

'

'

4.00%

'

5.00%

'

4.30%

Loss severity rate

'

'

'

'

'

53.50%

'

'

'

'

'

'

'

'

53.50%

Collateral spreads

'

'

'

'

'

'

'

'

'

'

2.60%

'

3.40%

'

3.30%

Estimated maturity dates (years)

'

'

'

'

'

'

'

'

'

'

'3 years 146 days

'

'4 years 183 days

'

'4 years 36 days

Weather curve

'

'

'

'

'

'

'

'

5,100

'

'

'

'

'

'

Weather standard deviation

'

'

'

'

'

'

'

'

55

'

'

'

'

'

'

FAIR_VALUE_MEASUREMENTS_DETAIL2

FAIR VALUE MEASUREMENTS (DETAILS 3) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	$34,817	$70,931
Transfers into Level 3	128	8,382
Transfers out of Level 3	0	0
Included in earnings	0	1,438
Included in OCI	-115	423
Purchases	0	212,889
Sales	0	-13,290
Settlements / distributions	-137	-124
Balance at end of period	34,693	280,649
Change in unrealized investment gain/loss relating to assets held at the reporting date	0	0
Other Investments [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	557,055	422,431
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	14,879	28,481
Included in OCI	0	0
Purchases	20,790	52,436
Sales	0	0
Settlements / distributions	-15,876	-21,941
Balance at end of period	576,848	481,407
Change in unrealized investment gain/loss relating to assets held at the reporting date	14,879	28,481
Other Assets [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	984	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	4,718	0
Included in OCI	0	0
Purchases	0	0
Sales	0	0
Settlements / distributions	-3,995	0
Balance at end of period	1,707	0
Change in unrealized investment gain/loss relating to assets held at the reporting date	1,540	0
Total Assets [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	592,856	493,362
Transfers into Level 3	128	8,382
Transfers out of Level 3	0	0
Included in earnings	19,597	29,919
Included in OCI	-115	423
Purchases	20,790	265,325
Sales	0	-13,290
Settlements / distributions	-20,008	-22,065
Balance at end of period	613,248	762,056
Change in unrealized investment gain/loss relating to assets held at the reporting date	16,419	28,481
Total Liabilities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	815	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	986	0
Included in OCI	0	0
Purchases	0	0
Sales	0	0
Settlements / distributions	-1,801	0
Balance at end of period	0	0
Change in unrealized investment gain/loss relating to assets held at the reporting date	0	0
Corporate Debt [Member] | Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	0	1,550
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	0	1,550
Included in OCI	0	0
Purchases	0	0
Sales	0	-3,100
Settlements / distributions	0	0
Balance at end of period	0	0
Change in unrealized investment gain/loss relating to assets held at the reporting date	0	0
Non-Agency RMBS [Member] | Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	0	1,110
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	0	0
Included in OCI	0	213
Purchases	0	0
Sales	0	0
Settlements / distributions	0	-23
Balance at end of period	0	1,300
Change in unrealized investment gain/loss relating to assets held at the reporting date	0	0
CMBS [Member] | Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	4,018	4,296
Transfers into Level 3	0	8,382
Transfers out of Level 3	0	0
Included in earnings	0	0
Included in OCI	-20	-78
Purchases	0	0
Sales	0	0
Settlements / distributions	-29	0
Balance at end of period	3,969	12,600
Change in unrealized investment gain/loss relating to assets held at the reporting date	0	0
ABS [Member] | Fixed Maturities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	30,799	63,975
Transfers into Level 3	128	0
Transfers out of Level 3	0	0
Included in earnings	0	-112
Included in OCI	-95	288
Purchases	0	212,889
Sales	0	-10,190
Settlements / distributions	-108	-101
Balance at end of period	30,724	266,749
Change in unrealized investment gain/loss relating to assets held at the reporting date	0	0
Hedge Funds [Member] | Other Investments [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	461,055	359,996
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	8,177	18,528
Included in OCI	0	0
Purchases	4,500	52,436
Sales	0	0
Settlements / distributions	-9,066	-13,808
Balance at end of period	464,666	417,152
Change in unrealized investment gain/loss relating to assets held at the reporting date	8,177	18,528
Direct Lending Funds [Member] | Other Investments [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	22,134	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	552	0
Included in OCI	0	0
Purchases	3,445	0
Sales	0	0
Settlements / distributions	-128	0
Balance at end of period	26,003	0
Change in unrealized investment gain/loss relating to assets held at the reporting date	552	0
CLO-Equities [Member] | Other Investments [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	73,866	62,435
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	6,150	9,953
Included in OCI	0	0
Purchases	12,845	0
Sales	0	0
Settlements / distributions	-6,682	-8,133
Balance at end of period	86,179	64,255
Change in unrealized investment gain/loss relating to assets held at the reporting date	6,150	9,953
Derivative [Member] | Other Assets [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	984	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	4,718	0
Included in OCI	0	0
Purchases	0	0
Sales	0	0
Settlements / distributions	-3,995	0
Balance at end of period	1,707	0
Change in unrealized investment gain/loss relating to assets held at the reporting date	1,540	0
Derivative [Member] | Other Liabilities [Member]	'	'
Changes in Level 3 Financial Instruments Measured at Fair Value on a Recurring Basis [Line Items]	'	'
Balance at beginning of period	815	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Included in earnings	986	0
Included in OCI	0	0
Purchases	0	0
Sales	0	0
Settlements / distributions	-1,801	0
Balance at end of period	0	0
Change in unrealized investment gain/loss relating to assets held at the reporting date	$0	$0

FAIR_VALUE_MEASUREMENTS_DETAIL3

FAIR VALUE MEASUREMENTS (DETAILS 4) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]	'	'
Senior notes	$1,490,198	$995,855
Estimate Of Fair Value [Member]	'	'
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]	'	'
Senior notes	$1,568,000	$1,073,000

DERIVATIVE_INSTRUMENTS_DETAILS

DERIVATIVE INSTRUMENTS (DETAILS) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	$7,611	$7,808
Liability Derivative Fair Value	2,131	1,967
Other Assets [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	7,611	7,808
Other Liabilities [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	2,131	1,967
Investment Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Derivative Notional Amount	329,121	254,023
Investment Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Other Assets [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	78	1,214
Investment Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Other Liabilities [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	2,060	1,032
Investment Portfolio [Member] | Interest Rate Swap [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Derivative Notional Amount	281,250	281,250
Investment Portfolio [Member] | Interest Rate Swap [Member] | Other Assets [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	145	873
Investment Portfolio [Member] | Interest Rate Swap [Member] | Other Liabilities [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	71	0
Underwriting Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Derivative Notional Amount	482,819	390,663
Underwriting Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Other Assets [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	5,681	4,737
Underwriting Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Other Liabilities [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	0	120
Underwriting Portfolio [Member] | Weather Related Derivative [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Derivative Notional Amount	5,000	24,451
Underwriting Portfolio [Member] | Weather Related Derivative [Member] | Other Assets [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Asset Derivative Fair Value	1,707	984
Underwriting Portfolio [Member] | Weather Related Derivative [Member] | Other Liabilities [Member] | Not Designated as Hedging Instruments [Member]	'	'
Derivative Fair Values on Consolidated Balance Sheet [Line Items]	'	'
Liability Derivative Fair Value	$0	$815

DERIVATIVE_INSTRUMENTS_DETAILS1

DERIVATIVE INSTRUMENTS (DETAILS 2) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'
Derivative assets - gross amounts	$9,262	$9,796
Derivative assets - gross amounts offset	-1,651	-1,988
Asset Derivative Fair Value	7,611	7,808
Derivative liabilities - gross amounts	3,782	3,955
Derivative liabilities - gross amounts offset	-1,651	-1,988
Liability Derivative Fair Value	$2,131	$1,967

DERIVATIVE_INSTRUMENTS_DETAILS2

DERIVATIVE INSTRUMENTS (DETAILS 3) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	$10,263	$9,652
Investment Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Net Realized Investment Gains (Losses) [Member]	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	-1,328	7,164
Investment Portfolio [Member] | Interest Rate Swap [Member] | Net Realized Investment Gains (Losses) [Member]	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	-4,161	0
Underwriting Portfolio [Member] | Foreign Exchange Forward Contracts [Member] | Foreign Exchange Gains (Losses) [Member]	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	12,074	2,488
Underwriting Portfolio [Member] | Weather Related Derivative [Member] | Other Insurance Related Income [Member]	'	'
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]	'	'
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	$3,678	$0

RESERVE_FOR_LOSSES_AND_LOSS_EX2

RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Reconciliation of Beginning and Ending Gross Unpaid Losses and Loss Expenses	'	'
Gross reserve for losses and loss expenses, beginning of period	$9,582,140	$9,058,731
Less reinsurance recoverable on unpaid losses, beginning of period	-1,900,112	-1,825,617
Net reserve for unpaid losses and loss expenses, beginning of period	7,682,028	7,233,114
Net incurred losses and loss expenses related to:	'	'
Current year	587,700	492,913
Prior years	-43,493	-54,499
Net incurred losses and loss expenses	544,207	438,414
Net paid losses and loss expenses related to:	'	'
Current year	-13,249	-10,846
Prior years	-444,466	-358,964
Net paid losses and loss expenses	-457,715	-369,810
Foreign exchange and other	14,501	-85,276
Net reserve for unpaid losses and loss expenses, end of period	7,783,021	7,216,442
Reinsurance recoverable on unpaid losses, end of period	1,884,820	1,881,261
Gross reserve for losses and loss expenses, end of period	$9,667,841	$9,097,703

RESERVE_FOR_LOSSES_AND_LOSS_EX3

RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net Favorable Prior Year Reserve Development [Line Items]	'	'
Net favorable prior year reserve development	$43,493	$54,499
Insurance [Member]	'	'
Net Favorable Prior Year Reserve Development [Line Items]	'	'
Net favorable prior year reserve development	11,608	5,598
Reinsurance [Member]	'	'
Net Favorable Prior Year Reserve Development [Line Items]	'	'
Net favorable prior year reserve development	$31,885	$48,901

RESERVE_FOR_LOSSES_AND_LOSS_EX4

RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS 3) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Additional Information Related to Net Incurred Losses [Line Items]	'	'
Net favorable prior year reserve development	$43,493	$54,499
Short Tail Lines Insurance And Reinsurance Business [Member]	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'
Net favorable prior year reserve development	29,000	30,000
Liability Reinsurance Business [Member]	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'
Net favorable prior year reserve development	6,000	16,000
Professional Lines Reinsurance Business [Member]	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'
Net favorable prior year reserve development	6,000	8,000
Credit And Surety Reinsurance Business [Member]	'	'
Additional Information Related to Net Incurred Losses [Line Items]	'	'
Net favorable prior year reserve development	'	$10,000

SHAREBASED_COMPENSATION_DETAIL

SHARE-BASED COMPENSATION (DETAILS) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]	'	'
Share based compensation expense incurred	$17,000,000	$14,000,000
Tax benefit related to share-based compensation costs incurred	3,000,000	2,000,000
Fair value - vested during period	61,000,000	59,000,000
Unrecognized share-based compensation costs	168,000,000	'
Unrecognized share-based compensation costs - weighted average period expected to be recognized	'2 years 9 months 15 days	'
Restricted Stock And Restricted Stock Units RSU [Member]	'	'
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]	'	'
Number of restricted stock and restricted stock units granted which will settle in cash	952,543	'
Liability for cash-settled units	$5,000,000	$1,000,000
Restricted Stock And Restricted Stock Units RSU [Member] | Performance [Member]	'	'
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]	'	'
Nonvested restricted stock (number) - beginning of period	283,000	'
Granted (number)	68,000	'
Vested (number)	0	'
Forfeited (number)	0	'
Nonvested restricted stock (number) - end of period	351,000	'
Weighted average grant date fair value - beginning of period	$35.74	'
Weighted average grant date fair value - granted	$44.33	'
Weighted average grant date fair value - vested	$0	'
Weighted average grant date fair value - forfeited	$0	'
Weighted average grant date fair value - end of period	$37.41	'
Number of restricted stock and restricted stock units granted which will settle in cash	22,837	'
Restricted Stock And Restricted Stock Units RSU [Member] | Service [Member]	'	'
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]	'	'
Nonvested restricted stock (number) - beginning of period	3,430,000	'
Granted (number)	988,000	'
Vested (number)	-1,230,000	'
Forfeited (number)	-60,000	'
Nonvested restricted stock (number) - end of period	3,128,000	'
Weighted average grant date fair value - beginning of period	$34.72	'
Weighted average grant date fair value - granted	$44.34	'
Weighted average grant date fair value - vested	$33.68	'
Weighted average grant date fair value - forfeited	$35.41	'
Weighted average grant date fair value - end of period	$38.03	'
Number of restricted stock and restricted stock units granted which will settle in cash	929,706	'

EARNINGS_PER_COMMON_SHARE_DETA

EARNINGS PER COMMON SHARE (DETAILS) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Basic earnings per common share	'	'
Net income	$148,471	$311,557
Less: noncontrolling interests	1,222	0
Less: preferred share dividends	10,022	8,741
Net income available to common shareholders	137,227	302,816
Weighted average common shares outstanding - basic	109,053	117,022
Basic earnings per common share	$1.26	$2.59
Diluted earnings per common share	'	'
Net income available to common shareholders	$137,227	$302,816
Weighted average common shares outstanding - basic	109,053	117,022
Stock compensation plans	1,338	1,636
Weighted average common shares outstanding - diluted	110,391	118,658
Diluted earnings per common share	$1.24	$2.55
Anti-dilutive shares excluded from the dilutive computation	1,051	912

SHAREHOLDERS_EQUITY_DETAILS

SHAREHOLDERS' EQUITY (DETAILS)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
			Common Stock [Member]	Common Stock [Member]
Class of Stock [Line Items]	'	'	'	'
Shares issued, balance at beginning of period	175,195,000	174,134,000	174,134,000	171,867,000
Shares issued	'	'	1,061,000	1,728,000
Total shares issued at end of period	175,195,000	174,134,000	175,195,000	173,595,000
Treasury shares, balance at beginning of period	-68,450,000	-64,649,000	-64,649,000	-53,947,000
Shares repurchased	'	'	-4,036,000	-3,369,000
Shares reissued from treasury	'	'	235,000	27,000
Total treasury shares at end of period	-68,450,000	-64,649,000	-68,450,000	-57,289,000
Total shares outstanding	106,745,000	109,485,000	106,745,000	116,306,000

SHAREHOLDERS_EQUITY_DETAILS_2

SHAREHOLDERS' EQUITY (DETAILS 2) (Common Stock [Member], USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Treasury Shares [Line Items]	'	'
Total shares	4,036,000	3,369,000
Total cost	$178,703	$130,768
Average price per share	$44.27	$38.81
Trident [Member]	'	'
Treasury Shares [Line Items]	'	'
Total shares	'	3,000,000
In the Open Market [Member]	'	'
Treasury Shares [Line Items]	'	'
Total shares	3,710,000	0
Total cost	164,606	0
Average price per share	$44.37	$0
From Employees [Member]	'	'
Treasury Shares [Line Items]	'	'
Total shares	326,000	369,000
Total cost	14,097	14,668
Average price per share	$43.14	$39.74
From Founding Shareholder [Member]	'	'
Treasury Shares [Line Items]	'	'
Total shares	0	3,000,000
Total cost	$0	$116,100
Average price per share	$0	$38.70

NONCONTROLLING_INTEREST_DETAIL

NONCONTROLLING INTEREST (DETAILS) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Noncontrolling Interest [Line Items]	'	'	'
Assets	$20,997,634,000	'	$19,634,784,000
Liabilities	15,119,363,000	'	13,766,822,000
Change in Noncontrolling Interest [Roll Forward]	'	'	'
Balance at January 1, 2014	50,000,000	'	'
Net income attributable to noncontrolling interests	1,222,000	0	'
Balance at March 31, 2014	51,222,000	'	'
Ventures Re [Member]	'	'	'
Noncontrolling Interest [Line Items]	'	'	'
Third party non-voting redeemable preferred share capital	50,000,000	'	'
Assets	58,000,000	'	50,000,000
Liabilities	$7,000,000	'	$0

DEBT_AND_FINANCING_ARRANGEMENT1

DEBT AND FINANCING ARRANGEMENTS (Details) (USD $)	3 Months Ended			3 Months Ended		0 Months Ended		0 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2013	Mar. 13, 2014	Mar. 31, 2014	Mar. 13, 2014	Mar. 31, 2014	Mar. 31, 2014
			2014 AXIS Specialty Finance PLC Senior Notes Due 2019 [Member]	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]
			AXIS Specialty Finance PLC [Member]			2014 AXIS Specialty Finance PLC Senior Notes Due 2019 [Member]	2014 AXIS Specialty Finance PLC Senior Notes Due 2019 [Member]	2014 AXIS Specialty Finance PLC Senior Notes Due 2045 [Member]	2014 AXIS Specialty Finance PLC Senior Notes Due 2045 [Member]	2004 AXIS Capital Holdings Limited Senior Notes [Member]
Senior notes [Line Items]	'	'	'	'	'	'	'	'	'	'
Face amount	'	'	'	'	'	'	$250,000,000	'	$250,000,000	$500,000,000
Interest rate	'	'	'	'	'	'	2.65%	'	5.15%	5.75%
Issue price (percentage of face amount)	'	'	'	'	'	99.90%	'	99.47%	'	'
Net proceeds on issuance	494,344,000	0	'	'	'	248,000,000	'	246,000,000	'	'
Percentage ownership in subsidiary	'	'	100.00%	'	'	'	'	'	'	'
Interest Expense	'	'	'	$16,000,000	$15,000,000	'	'	'	'	'

DEBT_AND_FINANCING_ARRANGEMENT2

DEBT AND FINANCING ARRANGEMENTS (Details 2) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Letter of Credit Facility [Member] | ING [Member]	'
Line of Credit Facility [Line Items]	'
Maximum capacity	$0
Letter of Credit Facility [Member] | Citibank [Member]	'
Line of Credit Facility [Line Items]	'
Maximum capacity	750
Letters of credit outstanding	462
Credit Facility [Member]	'
Line of Credit Facility [Line Items]	'
Maximum capacity	250
Letters of credit outstanding	0
Credit facility borrowings	$0

OTHER_COMPREHENSIVE_INCOME_LOS2

OTHER COMPREHENSIVE INCOME (LOSS) (DETAILS) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Before Tax Amount	'	'
Unrealized gains (losses) arising during the period	$80,560	($18,602)
Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	-16,069	-37,254
Unrealized gains (losses) arising during the period, net of reclassification adjustment	64,491	-55,856
Non-credit portion of OTTI losses	0	0
Foreign currency translation adjustment	2,659	-141
Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	0	0
Total other comprehensive income (loss)	67,150	-55,997
Tax (Expense) Benefit	'	'
Unrealized gains (losses) arising during the period	-9,177	77
Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	6,456	3,406
Unrealized gains (losses) arising during the period, net of reclassification adjustment	-2,721	3,483
Non-credit portion of OTTI losses	0	0
Foreign currency translation adjustment	0	0
Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	0	0
Total other comprehensive income (loss)	-2,721	3,483
Net of Tax Amount	'	'
Unrealized gains (losses) arising during the period	71,383	-18,525
Adjustment for reclassification of net realized investment gains and OTTI losses recognized in net income	-9,613	-33,848
Unrealized gains (losses) arising during the period, net of reclassification adjustment	61,770	-52,373
Non-credit portion of OTTI losses	0	0
Foreign currency translation adjustment	2,659	-141
Net change in benefit plan assets and obligations recognized in equity and reclassification adjustment	0	0
Total other comprehensive income (loss), net of tax	$64,429	($52,514)

OTHER_COMPREHENSIVE_INCOME_LOS3

OTHER COMPREHENSIVE INCOME (LOSS) (DETAILS 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]	'	'
Other realized investment gains	$11,406	$45,376
OTTI losses	-786	-898
Income before income taxes	152,596	321,688
General and administrative expenses	152,729	141,475
Tax expense	-4,125	-10,131
Net of tax	147,249	311,557
Unrealized appreciation on available for sale investments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]	'	'
Other realized investment gains	16,855	38,152
OTTI losses	-786	-898
Income before income taxes	16,069	37,254
Tax expense	-6,456	-3,406
Net of tax	$9,613	$33,848