Validus 10-Q 8 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Nov. 06, 2013
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'VALIDUS HOLDINGS LTD	'
Entity Central Index Key	'0001348259	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Current Fiscal Year End Date	'--12-31	'
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	99,404,743

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets	'	'
Fixed maturities, at fair value (amortized cost: 2013—$5,415,864; 2012—$5,008,514)	$5,438,265	$5,085,334
Short-term investments at fair value (amortized cost: 2013—$761,631; 2012—$1,112,929)	761,642	1,114,250
Other investments at fair value (cost: 2013—$606,485; 2012—$583,068)	559,472	564,448
Cash and cash equivalents	1,254,618	1,219,379
Total investments and cash	8,013,997	7,983,411
Investments in affiliates	111,814	172,329
Premiums receivable	1,050,073	802,159
Deferred acquisition costs	166,539	146,588
Prepaid reinsurance premiums	169,062	99,593
Securities lending collateral	1,021	225
Loss reserves recoverable	421,518	439,967
Paid losses recoverable	30,074	46,435
Income taxes recoverable	4,127	0
Intangible assets	107,449	110,569
Goodwill	20,393	20,393
Accrued investment income	17,821	21,321
Other assets	203,480	177,274
Total assets	10,317,368	10,020,264
Liabilities	'	'
Reserve for losses and loss expenses	3,223,735	3,517,573
Unearned premiums	1,169,830	894,362
Reinsurance balances payable	159,590	138,550
Securities lending payable	1,487	691
Deferred income taxes	22,993	20,259
Net payable for investments purchased	33,066	38,346
Accounts payable and accrued expenses	139,098	167,577
Variable funding notes	437,970	0
Senior notes payable	247,171	247,090
Debentures payable	541,127	540,709
Total liabilities	5,976,067	5,565,157
Commitments and contingent liabilities	'	'
Shareholders' equity	'	'
Common shares, 571,428,571 authorized, par value $0.175 (Issued: 2013—154,386,316; 2012—152,698,191; Outstanding: 2013—99,897,996; 2012—107,921,259)	27,018	26,722
Treasury shares (2013—54,488,320; 2012—44,776,932)	-9,535	-7,836
Additional paid-in-capital	1,824,342	2,160,478
Accumulated other comprehensive (loss)	-3,872	-2,953
Retained earnings	1,946,209	1,844,416
Total shareholders' equity attributable to Validus	3,784,162	4,020,827
Noncontrolling interest	557,139	434,280
Total shareholders' equity	4,341,301	4,455,107
Total liabilities and shareholders' equity	$10,317,368	$10,020,264

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Assets	'	'
Fixed maturities, at amortized cost	$5,415,864	$5,008,514
Short-term investments, at amortized cost	761,631	1,112,929
Other investments, at cost	$606,485	$583,068
Shareholders' equity	'	'
Common shares, shares authorized	571,428,571	571,428,571
Common shares, par value	$0.18	$0.18
Common shares, shares issued	154,386,316	152,698,191
Common shares, shares outstanding	99,897,996	107,921,259
Treasury stock, common shares	54,488,320	44,776,932

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended			9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Revenues	'	'		'	'
Gross premiums written	$356,760	$390,215		$2,163,833	$1,854,593
Reinsurance premiums ceded	-39,415	-45,743		-348,027	-271,847
Net premiums written	317,345	344,472		1,815,806	1,582,746
Change in unearned premiums	213,943	130,632		-205,999	-208,816
Net premiums earned	531,288	475,104		1,609,807	1,373,930
Net investment income	20,009	25,489		71,868	79,134
Net realized (losses) gains on investments	-6,320	9,063		-1,190	22,749
Net unrealized gains (losses) on investments	69,967	86,345		-78,618	53,442
Income (loss) from investment affiliate	1,044	-160		4,274	-558
Other (loss) income	-2,806	7,324		4,297	22,209
Foreign exchange gains	6,036	1,103		4,735	3,617
Total revenues	619,218	604,268		1,615,173	1,554,523
Expenses	'	'		'	'
Losses and loss expenses	177,965	155,455		587,780	541,136
Policy acquisition costs	94,900	98,623		275,663	252,884
General and administrative expenses	81,089	70,547		232,335	198,557
Share compensation expenses	10,527	7,345		19,483	19,583
Finance expenses	27,132	9,362		89,408	39,347
Transaction expenses	0	3,784	[1]	0	3,784	[1]
Total expenses	391,613	345,116		1,204,669	1,055,291
Income before taxes and income from operating affiliates	227,605	259,152		410,504	499,232
Tax (expense) benefit	-5	-1,343		220	-1,886
Income from operating affiliates	1,463	6,235		8,779	13,194
Net income	229,063	264,044		419,503	510,540
Net (income) loss attributable to noncontrolling interest	-45,694	-56,746		17,831	-11,386
Net income available to Validus	183,369	207,298		437,334	499,154
Other comprehensive income (loss)	'	'		'	'
Foreign currency translation adjustments	4,390	1,400		-5,209	2,036
Other comprehensive income (loss)	4,390	1,400		-5,209	2,036
Comprehensive income available to Validus	$187,759	$208,698		$432,125	$501,190
Weighted average number of common shares and common share equivalents outstanding	'	'		'	'
Basic	99,834,563	93,368,775		103,451,396	97,016,034
Diluted	103,613,766	98,236,490		105,264,913	102,333,515
Basic earnings per share available to common shareholders	$1.82	$2.20		$4.06	$5.09
Diluted earnings per share available to common shareholders	$1.77	$2.11		$3.99	$4.88
Cash dividends declared per share	$0.30	$0.25		$2.90	$0.75
[1]	The transaction expenses relate to costs incurred in connection with the acquisition of Flagstone Reinsurance Holdings, S.A.

Consolidated_Statements_of_Sha

Consolidated Statements of Shareholders' Equity (Unaudited) (USD $)	Total	Common shares	Treasury shares	Additional paid-in capital	Accumulated other comprehensive (loss)	Retained earnings
In Thousands
Beginning balance at Dec. 31, 2011	'	$23,538	($6,131)	$1,893,890	($6,601)	$1,543,729
Common shares (redeemed) issued, net	'	373	'	2,551	'	'
Repurchase of common shares	'	'	-1,418	-258,257	'	'
Share compensation expenses	'	'	'	19,583	'	'
Amounts reclassified from/to accumulated other comprehensive income	'	'	'	'	0	0
Other comprehensive (loss) income	2,036	'	'	'	2,036	'
Dividends	'	'	'	'	'	-78,594
Net income	510,540	'	'	'	'	510,540
Net (income) loss attributable to noncontrolling interest	-11,386	'	'	'	'	-11,386
Noncontrolling interest	461,486	'	'	'	'	'
Total shareholders' equity at Sep. 30, 2012	4,095,339	'	'	'	'	'
Ending balance at Sep. 30, 2012	3,633,853	23,911	-7,549	1,657,767	-4,565	1,964,289
Beginning balance at Dec. 31, 2012	4,020,827	26,722	-7,836	2,160,478	-2,953	1,844,416
Common shares (redeemed) issued, net	'	296	'	-134	'	'
Repurchase of common shares	'	'	-1,699	-355,485	'	'
Share compensation expenses	'	'	'	19,483	'	'
Amounts reclassified from/to accumulated other comprehensive income	'	'	'	'	4,290	-4,290
Other comprehensive (loss) income	-5,209	'	'	'	-5,209	'
Dividends	'	'	'	'	'	-331,251
Net income	419,503	'	'	'	'	419,503
Net (income) loss attributable to noncontrolling interest	17,831	'	'	'	'	17,831
Noncontrolling interest	557,139	'	'	'	'	'
Total shareholders' equity at Sep. 30, 2013	4,341,301	'	'	'	'	'
Ending balance at Sep. 30, 2013	$3,784,162	$27,018	($9,535)	$1,824,342	($3,872)	$1,946,209

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows provided by (used in) operating activities	'	'
Net income	$419,503	$510,540
Adjustments to reconcile net income to cash provided by (used in) operating activities:	'	'
Share compensation expenses	19,483	19,583
Amortization of discount on senior notes	81	81
(Income) loss from investment affiliate	-4,274	558
Net realized losses (gains) on investments	1,190	-22,749
Net unrealized losses (gains) on investments	78,618	-53,442
Amortization of intangible assets	3,120	3,120
(Income) from operating affiliates	-8,779	-13,194
Foreign exchange losses (gains) included in net income	4,927	-17,064
Amortization of premium on fixed maturities	14,870	19,214
Change in:	'	'
Premiums receivable	-226,154	-132,292
Deferred acquisition costs	-19,951	-33,951
Prepaid reinsurance premiums	-69,469	-53,407
Loss reserves recoverable	20,411	57,574
Paid losses recoverable	16,218	54,559
Income taxes recoverable	-3,099	-5,041
Accrued investment income	3,466	6,015
Other assets	-11,214	-16,050
Reserve for losses and loss expenses	-293,673	-80,954
Unearned premiums	275,468	262,223
Reinsurance balances payable	-634	-33,487
Deferred income taxes	2,565	6,241
Accounts payable and accrued expenses	-37,183	4,948
Net cash provided by operating activities	185,490	483,025
Cash flows provided by (used in) investing activities	'	'
Proceeds on sales of investments	3,598,080	2,528,442
Proceeds on maturities of investments	406,079	385,642
Purchases of fixed maturities	-4,414,320	-2,832,179
Sales of short-term investments, net	348,554	5,123
(Purchases) of other investments	-21,793	-499,178
(Increase) in securities lending collateral	-796	-2,387
Redemption from (purchase of) investment in operating affiliates	86,657	-26,500
Purchase of investment in investment affiliate	-13,089	-3,798
Net cash (used in) investing activities	-10,628	-444,835
Cash flows provided by (used in) financing activities	'	'
Net proceeds on issuance of variable funding notes	418,299	0
Issuance of common shares, net	162	2,924
Purchases of common shares under share repurchase program	-357,184	-259,675
Dividends paid	-329,201	-81,391
Increase in securities lending payable	796	2,387
Third party investment in noncontrolling interest	140,690	450,100
Net cash (used in) provided by financing activities	-126,438	114,345
Effect of foreign currency rate changes on cash and cash equivalents	-13,185	20,450
Net increase in cash	35,239	172,985
Cash and cash equivalents - beginning of period	1,219,379	832,844
Cash and cash equivalents - end of period	1,254,618	1,005,829
Taxes paid during the period	438	3,640
Interest paid during the period	$44,112	$37,122

Basis_of_preparation_and_conso

Basis of preparation and consolidation	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of presentation and consolidation	'
	Basis of preparation and consolidation
	These unaudited consolidated financial statements include Validus Holdings, Ltd. and its subsidiaries (together, the "Company") and have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 in Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In addition, the year-end balance sheet data was derived from audited financial statements but does not include all disclosures required by U.S. GAAP. This Quarterly Report should be read in conjunction with the financial statements included in the Company's Annual Report on Form 10-K/A for the year ended December 31, 2012, as filed with the U.S. Securities and Exchange Commission (the "SEC").
	In the opinion of management, these unaudited consolidated financial statements reflect all adjustments (including normal recurring adjustments) considered necessary for a fair presentation of the Company's financial position and results of operations as at the end of and for the periods presented. Certain amounts in prior periods have been reclassified to conform to current period presentation. All intercompany accounts and transactions have been eliminated. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The significant estimates reflected in the Company's consolidated financial statements include the reserve for losses and loss expenses, premium estimates for business written on a line slip or proportional basis, reinsurance premiums ceded and reinsurance recoverable balances including the provision for unrecoverable reinsurance recoverable balances and investment valuation. Actual results could differ materially from those estimates. The results of operations for any interim period are not necessarily indicative of the results for a full year. The term "ASC" used in these notes refers to the Accounting Standard Codification issued by the United States Financial Accounting Standards Board ("FASB").
	On November 30, 2012, the Company acquired all of the outstanding common shares of Flagstone Reinsurance Holdings, S.A. ("Flagstone") in exchange for 0.1935 Company common shares and $2.00 in cash per Flagstone common share (the "Flagstone Acquisition"). For segmental reporting purposes, the results of Flagstone’s operations since the acquisition date have been included within the Validus Re segment in the consolidated financial statements.
	On April 25, 2013, the Company acquired Longhorn Re, Ltd., a single contract Bermuda domiciled crop reinsurer.

Recent_accounting_pronouncemen

Recent accounting pronouncements	9 Months Ended
	Sep. 30, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recent accounting pronouncements	'
	Recent accounting pronouncements
	(a) Adoption of new accounting standards
	Disclosures about Offsetting Assets and Liabilities
	In December 2011, the FASB issued Accounting Standards Update No. 2011-11, "Disclosures about Offsetting Assets and Liabilities" ("ASU 2011-11"). The objective of ASU 2011-11 is to enhance disclosures by requiring improved information about financial instruments and derivative instruments in relation to netting arrangements.
	Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities
	In January 2013, the FASB issued Accounting Standards Update No. 2013-01, “Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities” (“ASU 2013-01”). The objective of ASU 2013-01 is to address implementation issues about the scope of ASU 2011-11, Disclosures about Offsetting Assets and Liabilities. The amendments clarify that the scope of ASU 2011-11 applies to derivatives, including bifurcated embedded derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing and securities lending transactions that are either or subject to an enforceable master netting arrangement or similar agreement. Entities with other types of financial assets and financial liabilities subject to a master netting arrangement or similar agreement also are affected because these amendments make them no longer subject to the disclosure requirements in ASU 2011-11. ASU 2011-11 and 2013-01 became effective for fiscal periods beginning on or after January 1, 2013, and as a result, the Company adopted ASU 2011-11 and 2013-01 effective January 1, 2013. The adoption of these new accounting standards impacts disclosures only; therefore they did not have an impact on the Company's consolidated financial statements. Please refer to Note 7: "Derivative instruments".
	Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income
	In February 2013, the FASB issued Accounting Standard Update No. 2013-02, “Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income” (“ASU 2013-02”). The objective of this update is to improve the reporting of reclassifications out of accumulated other comprehensive income. The amendments do not change the current requirements for reporting net income or other comprehensive income in financial statements. However, the amendments require an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. The amendments became effective for reporting periods beginning after December 15, 2012, and as a result, the Company adopted ASU 2013-02 effective January 1, 2013. Please refer to Note 14 "Accumulated other comprehensive income (loss)."
	Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedge Accounting Purposes
	In July 2013, the FASB issued Accounting Standard Update No. 2013-10, “Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedge Accounting Purposes” (“ASU 2013-10”). The amendments in this Update permit the Fed Funds Effective Swap Rate also referred to as the overnight index swap rate (“OIS”) to be used as a U.S. benchmark interest rate for hedge accounting purposes in addition to U.S. Treasury rate and LIBOR. The amendments also remove the restriction on using different benchmark rates for similar hedges. Before the amendments in this Update, only the U.S. Treasury rate and the LIBOR swap rate were considered benchmark interest rates in the United States. The amendments are effective prospectively for qualifying new or redesignated hedging relationships entered into on or after July 17, 2013. The adoption of this standard update did not have an impact on the Company's consolidated financial statements.
	(b) Recently issued accounting standards not yet adopted
	In March 2013, the FASB issued Accounting Standard Update No. 2013-05, “Parent's Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity” (“ASU 2013-05”). The objective of this update is to resolve the diversity in practice about whether Subtopic 810-10, Consolidation-Overall, or Subtopic 830-30, Foreign Currency Matters-Translation of Financial Statements, applies to the release of the cumulative translation adjustment into net income when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary within a foreign entity. The amendments in this Update are effective prospectively for fiscal years (and interim reporting periods within those years) beginning after December 15, 2013. Early adoption is permitted. The Company is currently evaluating the impact of this guidance; however it is not expected to have a material impact on the Company's consolidated financial statements.
	In June 2013, the FASB issued Accounting Standard Update No. 2013-08, “Financial Services - Investment Companies - Amendments to the Scope, Measurement, and Disclosure Requirements” (“ASU 2013-08”). The amendments in this Update change the assessment of whether an entity is an investment company by developing a new two-tiered approach for that assessment, which requires an entity to possess certain fundamental characteristics while allowing judgment in assessing other typical characteristics. The new approach requires an entity to assess all of the characteristics of an investment company and consider its purpose and design to determine whether it is an investment company. The amendments in this Update are effective prospectively for fiscal years (and interim reporting periods within those years) beginning after December 15, 2013. Early adoption is prohibited. The Company is currently evaluating the impact of this guidance; however it is not expected to have a material impact on the Company's consolidated financial statements.
	In July 2013, the FASB issued Accounting Standard Update No. 2013-11 “Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists” (“ASU 2013-11”). This Update applies to all entities that have unrecognized tax benefits when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists at the reporting date. An unrecognized tax benefit should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. To the extent a net operating loss carryforward is not available to settle any additional income taxes that would result from the disallowance of a tax position at the reporting date, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The amendments in this Update are effective for fiscal years beginning after December 15, 2013. The Company is currently evaluating the impact of this guidance; however it is not expected to have a material impact on the Company's consolidated financial statements.

Investments

Investments	9 Months Ended
	Sep. 30, 2013
Investments [Abstract]	'
Investments	'
	Investments
	(a) Trading Securities
	The Company's investments in fixed maturities, short-term investments and other investments are classified as trading and carried at fair value, with related net unrealized gains or losses included in earnings.
	The amortized cost (or cost), gross unrealized gains and (losses) and estimated fair value of investments at September 30, 2013 were as follows:
		Amortized Cost or Cost			Gross Unrealized Gains				Gross Unrealized Losses				Estimated Fair Value
	U.S. government and government agency	$	1,319,499		$	4,313			$	(3,329	)		$	1,320,483
	Non-U.S. government and government agency	401,149			4,028				(1,180		)		403,997
	U.S. states, municipalities and political subdivisions	43,912			440				(423		)		43,929
	Agency residential mortgage-backed securities	313,177			8,384				(1,360		)		320,201
	Non-agency residential mortgage-backed securities	24,029			164				(1,062		)		23,131
	U.S. corporate	1,363,418			10,616				(6,889		)		1,367,145
	Non-U.S. corporate	686,656			5,658				(3,264		)		689,050
	Bank loans	732,922			5,421				(1,885		)		736,458
	Catastrophe bonds	56,504			2,358				—				58,862
	Asset-backed securities	474,598			1,279				(868		)		475,009
	Total fixed maturities	5,415,864			42,661				(20,260		)		5,438,265
	Total short-term investments	761,631			12				(1		)		761,642
	Other investments
	Fund of hedge funds	3,274			97				(921		)		2,450
	Private equity investments	12,493			2,259				(79		)		14,673
	Hedge funds (a)	584,519			46,087				(97,261		)		533,345
	Mutual funds	6,199			2,805				—				9,004
	Total other investments	606,485			51,248				(98,261		)		559,472
	Total	$	6,783,980		$	93,921			$	(118,522	)		$	6,759,379
	Noncontrolling interest (a)	$	(527,850	)	$	(40,887	)		$	87,535			$	(481,202	)
	Total investments excluding noncontrolling interest	$	6,256,130		$	53,034			$	(30,987	)		$	6,278,177
	(a)	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
	The amortized cost (or cost), gross unrealized gains and (losses) and estimated fair value of investments at December 31, 2012 were as follows:
		Amortized Cost or Cost			Gross Unrealized Gains				Gross Unrealized Losses				Estimated Fair Value
	U.S. government and government agency	$	1,091,357		$	7,957			$	(84	)		$	1,099,230
	Non-U.S. government and government agency	295,602			6,904				(227		)		302,279
	U.S. states, municipalities and political subdivisions	41,286			800				(23		)		42,063
	Agency residential mortgage-backed securities	375,368			13,708				(202		)		388,874
	Non-agency residential mortgage-backed securities	106,536			1,266				(1,346		)		106,456
	U.S. corporate	1,189,173			21,681				(681		)		1,210,173
	Non-U.S. corporate	582,115			11,373				(223		)		593,265
	Bank loans	663,217			10,593				(427		)		673,383
	Catastrophe bonds	56,757			481				(291		)		56,947
	Asset-backed securities	607,103			5,767				(206		)		612,664
	Total fixed maturities	5,008,514			80,530				(3,710		)		5,085,334
	Total short-term investments	1,112,929			1,349				(28		)		1,114,250
	Other investments
	Fund of hedge funds	4,677			299				(219		)		4,757
	Private equity investments	12,857			94				—				12,951
	Hedge funds (a)	559,335			21,814				(42,623		)		538,526
	Mutual funds	6,199			2,015				—				8,214
	Total other investments	583,068			24,222				(42,842		)		564,448
	Total	$	6,704,511		$	106,101			$	(46,580	)		$	6,764,032
	Noncontrolling interest (a)	(450,000		)	(19,427		)		36,690				(432,737		)
	Total investments excluding noncontrolling interest	$	6,254,511		$	86,674			$	(9,890	)		$	6,331,295
	(a)	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
	The following table sets forth certain information regarding the investment ratings of the Company’s fixed maturities portfolio as at September 30, 2013 and December 31, 2012. Investment ratings are the lower of Moody’s or Standard & Poor’s rating for each investment security, presented in Standard & Poor’s equivalent rating. For investments where Moody’s and Standard & Poor’s ratings are not available, Fitch ratings are used and presented in Standard & Poor’s equivalent rating.
		September 30, 2013						December 31, 2012
		Estimated Fair Value			% of Total			Estimated Fair Value				% of Total
	AAA	$	776,896		14.3	%		$	1,062,794			20.9	%
	AA	2,256,592			41.5	%		1,862,322				36.6	%
	A	1,196,037			22	%		1,049,969				20.6	%
	BBB	423,228			7.8	%		374,447				7.4	%
	Investment grade	4,652,753			85.6	%		4,349,532				85.5	%
	BB	356,205			6.5	%		373,907				7.4	%
	B	397,888			7.3	%		330,416				6.5	%
	CCC	4,754			0.1	%		4,483				0.1	%
	CC	2,821			0.1	%		3,259				0.1	%
D/NR	23,844			0.4	%		23,737				0.4	%
Non-Investment grade	785,512			14.4	%		735,802				14.5	%
Total Fixed Maturities	$	5,438,265		100	%		$	5,085,334			100	%
The amortized cost and estimated fair value amounts for fixed maturity securities held at September 30, 2013 and December 31, 2012 are shown below by contractual maturity. Actual maturity may differ from contractual maturity because certain borrowers may have the right to call or prepay certain obligations with or without call or prepayment penalties.
	September 30, 2013							December 31, 2012
	Amortized Cost			Estimated Fair Value				Amortized Cost				Estimated Fair Value
Due in one year or less	$	745,812		$	750,992			$	526,529			$	530,499
Due after one year through five years	3,492,605			3,504,812				2,971,118				3,018,544
Due after five years through ten years	362,563			361,011				418,377				424,304
Due after ten years	3,080			3,109				3,483				3,993
	4,604,060			4,619,924				3,919,507				3,977,340
Asset-backed and mortgage-backed securities	811,804			818,341				1,089,007				1,107,994
Total Fixed Maturities	$	5,415,864		$	5,438,265			$	5,008,514			$	5,085,334
(b)  Net investment income
Net investment income was derived from the following sources:
	Three Months Ended							Nine Months Ended
	September 30,			September 30,				September 30,				September 30,
	2013			2012				2013				2012
Fixed maturities and short-term investments	$	20,936		$	25,703			$	74,618			$	79,450
Cash and cash equivalents	1,079			1,770				3,241				5,536
Securities lending income	3			3				3				9
Total gross investment income	22,018			27,476				77,862				84,995
Investment expenses	(2,009		)	(1,987		)		(5,994		)		(5,861		)
Net investment income	$	20,009		$	25,489			$	71,868			$	79,134
(c)	Net realized gains (losses) and change in net unrealized gains (losses)
The following represents an analysis of net realized gains (losses) and the change in net unrealized (losses) on investments:
	Three Months Ended							Nine Months Ended
	September 30,			September 30,				September 30,				September 30,
	2013			2012				2013				2012
Fixed maturities, short-term and other investments and cash equivalents
Gross realized gains	$	7,706		$	10,187			$	25,578			$	29,610
Gross realized (losses)	(14,026		)	(1,124		)		(26,768		)		(6,861		)
Net realized (losses) gains on investments	(6,320		)	9,063				(1,190		)		22,749
Net unrealized gains on securities lending	—			223				—				260
Change in net unrealized gains (losses) on investments	69,967			86,122				(78,618		)		53,182
Net change in unrealized gains (losses) on investments	$	69,967		$	86,345			$	(78,618	)		$	53,442
Total net realized (losses) gains and change in net unrealized gains (losses) on investments	$	63,647		$	95,408			$	(79,808	)		$	76,191
Noncontrolling interest (a)	(42,578		)	(55,806		)		25,767				(10,924		)
Total net realized gains and change in net unrealized (losses) on investments excluding noncontrolling interest	$	21,069		$	39,602			$	(54,041	)		$	65,267
(a)	Includes change in net unrealized (gains) losses on investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
(d) Pledged investments
The following tables outline investments pledged as collateral under the Company's credit facilities. For further details of the credit facilities, please refer to Note 12: “Debt and financing arrangements.”
		September 30, 2013
Description		Commitment			Issued and Outstanding				Investments pledged as collateral
$400,000 syndicated unsecured letter of credit facility		$	400,000		$	—			$	—
$525,000 syndicated secured letter of credit facility		525,000			371,990				491,761
$200,000 secured bi-lateral letter of credit facility		200,000			77,626				129,768
Talbot FAL Facility		25,000			25,000				36,996
PaCRe senior secured letter of credit facility		10,000			258				—
IPC bi-lateral facility		40,000			26,019				98,260
$375,000 Flagstone bi-lateral facility		375,000			297,996				453,241
		$	1,575,000		$	798,889			$	1,210,026
		31-Dec-12
Description		Commitment			Issued and Outstanding				Investments pledged as collateral
$400,000 syndicated unsecured letter of credit facility		$	400,000		$	—			$	—
$525,000 syndicated secured letter of credit facility		525,000			376,570				517,210
$500,000 secured bi-lateral letter of credit facility		500,000			92,402				125,991
Talbot FAL Facility		25,000			25,000				41,372
PaCRe senior secured letter of credit facility		10,000			219				—
IPC bi-lateral facility		80,000			40,613				98,593
$550,000 Flagstone bi-lateral facility		550,000			381,019				416,414
		$	2,090,000		$	915,823			$	1,199,580

Fair_value_measurements

Fair value measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair value measurements	'
	Fair value measurements
	The Company has adopted all authoritative guidance in effect as of the balance sheet date regarding certain market conditions that allow for fair value measurements that incorporate unobservable inputs where active market transaction based measurements are unavailable.
	(a)	Classification within the fair value hierarchy
	Under U.S. GAAP, a company must determine the appropriate level in the fair value hierarchy for each fair value measurement. The fair value hierarchy prioritizes the inputs, which refer broadly to assumptions market participants would use in pricing an asset or liability, into three levels. It gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The level in the fair value hierarchy within which a fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety.
	The three levels of the fair value hierarchy are described below:
	•	Level 1 - Fair values are measured based on unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access.
	•	Level 2 - Fair values are measured 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 - Fair values are measured based on inputs that are unobservable and significant to the overall fair value measurement. The unobservable inputs reflect our own judgments about assumptions where there is little, if any, market activity for that asset or liability 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 instrument. 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 (for example, from market to cash flow approach) or may cause us to use multiple valuation techniques to estimate the fair value of a financial instrument. These circumstances could cause an instrument to be reclassified between levels within the fair value hierarchy.
	There have been no material changes in the Company's valuation techniques during the period, or periods, represented by these consolidated financial statements. The following methods and assumptions were used in estimating the fair value of each class of financial instrument recorded in the Consolidated Balance Sheets.
	(b) Level 1 and Level 2 assets measured at fair value
	Fixed maturity investments
	Fixed maturity investments included in Level 2 are U.S. government and government agency, non-U.S. government and government agency, U.S. states, municipalities and political subdivisions, agency residential mortgage-backed securities, non-agency residential mortgage-backed securities, U.S. corporate, non-U.S. corporate, bank loans, catastrophe bonds and asset backed securities.
	In general, the Company's fixed maturity investment portfolios are priced using pricing services, such as index providers and pricing vendors, as well as broker quotations. The pricing vendors provide pricing for a high volume of liquid securities that are actively traded. For securities that do not trade on an exchange, the pricing services generally utilize market data and other observable inputs in matrix pricing models to determine month end prices. Prices are generally verified using third party data. Securities which are priced by an index provider are generally included in the index.
	In general, broker-dealers value securities through their trading desks based on observable inputs. The methodologies include mapping securities based on trade data, bids or offers, observed spreads, and performance on newly issued securities. Broker-dealers also determine valuations by observing secondary trading of similar securities. Prices obtained from broker quotations are considered non-binding, however they are based on observable inputs and by observing secondary trading of similar securities obtained from active, non-distressed markets.
	The Company considers these Level 2 inputs as they are corroborated with other market observable inputs. The techniques generally used to determine the fair value of the Company's fixed maturity investments are detailed below by asset class.
	U.S. government and government agency
	Level 2 - U.S. government and government agency securities consist primarily of debt securities 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. Fixed maturity investments included in U.S. government and government agency securities are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources and integrate other observations from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The fair value of each security is individually computed using analytical models which incorporate option adjusted spreads and other daily interest rate data.
	Non-U.S. government and government agency
	Level 2 - Non-U.S. government and government agency securities consist of debt securities issued by non-U.S. governments and their agencies along with supranational organizations (also known as sovereign debt securities). Securities held in these sectors are primarily priced by pricing services who employ proprietary discounted cash flow models to value the securities. Key quantitative inputs for these models are daily observed benchmark curves for treasury, swap and high issuance credits. The pricing services then apply a credit spread for each security which is developed by in-depth and real time market analysis. For securities in which trade volume is low, the pricing services utilize data from more frequently traded securities with similar attributes. These models may also be supplemented by daily market and credit research for international markets.
	U.S. states, municipalities and political subdivisions
	Level 2 - The Company's U.S. states, municipalities and political subdivisions portfolio contains debt securities issued by U.S. domiciled state and municipal entities. These securities are generally priced by independent pricing services using the techniques described for U.S. government and government agency securities described above.
	Agency residential mortgage-backed securities
	Level 2 - The Company's agency residential mortgage-backed investments are primarily priced by pricing services using a mortgage pool specific model which utilizes daily inputs from the active to be announced ("TBA") market which is very liquid, as well as the U.S. treasury market. The model also utilizes additional information, such as the weighted average maturity, weighted average coupon and other available pool level data which is provided by the sponsoring agency. Valuations are also corroborated with daily active market quotes.
	Non-agency residential mortgage-backed securities
	Level 2 - The Company's non-agency mortgage-backed investments include non-agency prime residential mortgage-backed fixed maturity investments. The Company has no fixed maturity investments classified as sub-prime held in its fixed maturity investments portfolio. Securities held in these sectors are primarily priced by pricing services using an option adjusted spread ("OAS") model or other relevant models, which principally utilize inputs including benchmark yields, available trade information or broker quotes, and issuer spreads. The pricing services also review collateral prepayment speeds, loss severity and delinquencies among other collateral performance indicators for the securities valuation, when applicable.
	U.S. corporate
	Level 2 - Corporate debt securities consist primarily of investment-grade debt of a wide variety of U.S. corporate issuers and industries. The Company's corporate fixed maturity investments are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources regarding the issuer of the security and obtain credit data, as well as other observations, from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The pricing services also consider the specific terms and conditions of the securities, including any specific features which may influence risk. In certain instances, securities are individually evaluated using a spread which is added to the U.S. treasury curve or a security specific swap curve as appropriate.
	Non - U.S. corporate
	Level 2 - Non - U.S. corporate debt securities consist primarily of investment-grade debt of a wide variety of non-U.S. corporate issuers and industries. The Company's non - U.S. corporate fixed maturity investments are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources regarding the issuer of the security and obtain credit data, as well as other observations, from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The pricing services also consider the specific terms and conditions of the securities, including any specific features which may influence risk.
	Bank loans
	Level 2 - The Company's bank loan investments consist primarily of below-investment-grade debt of a wide variety of corporate issuers and industries. The Company's bank loans are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources regarding the issuer of the security and obtain credit data, as well as other observations, from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The pricing services also consider the specific terms and conditions of the securities, including any specific features which may influence risk.
	Catastrophe bonds
	Level 2 - Catastrophe bonds are based on broker or underwriter bid indications.
	Asset-backed securities
	Level 2 - Asset backed securities include mostly investment-grade debt securities backed by pools of loans with a variety of underlying collateral, including automobile loan receivables, student loans, credit card receivables, and collateralized loan obligations originated by a variety of financial institutions. Securities held in these sectors are primarily priced by pricing services. The pricing services apply dealer quotes and other available trade information such as bids and offers, prepayment speeds which may be adjusted for the underlying collateral or current price data, the U.S. treasury curve and swap curve as well as cash settlement. The pricing services determine the expected cash flows for each security held in this sector using historical prepayment and default projections for the underlying collateral and current market data. In addition, a spread is applied to the relevant benchmark and used to discount the cash flows noted above to determine the fair value of the securities held in this sector.
	Short term investments
	Level 1 & Level 2 - Short term investments consist primarily of highly liquid securities, all with maturities less than one year from the date of purchase. The fair value of the Company's portfolio of short term investments are generally determined using amortized cost which approximates fair value. The Company determined that certain of its short-term investments held in highly liquid money market-type funds would be included in Level 1 as their fair values are based on quoted market prices in active markets. The remaining 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.
	Mutual funds
	Level 2 -Mutual funds consist of two investment funds which are invested in various quoted investments. The fair value of units in the mutual funds is based on the net asset value of the fund as reported by the fund manager.
	(c) Level 3 assets measured at fair value
	Other investments
	Level 3 includes financial instruments that are valued using market approach and income approach valuation techniques. These models incorporate both observable and unobservable inputs. The Company's hedge funds, a fund of hedge funds and private equity investments are the only financial instruments in this category as at September 30, 2013. For each respective hedge fund investment, the Company obtains and reviews the valuation methodology used by the fund administrators and investment managers to ensure that the hedge fund investments are following fair value principles consistent with U.S. GAAP in determining the net asset value (“NAV”).
	Within the hedge fund industry, 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 and regular evaluation of fund performance against applicable benchmarks.
	Hedge funds
	The hedge funds were valued at $533,345 at September 30, 2013. The hedge funds consist of an investment in four Paulson & Co. managed funds (the "Paulson hedge funds") and two investment funds assumed from the Flagstone Acquisition (the "Flagstone investment funds"). The Paulson hedge funds' administrator provides monthly reported NAVs with a one-month delay in its valuation. As a result, the funds' administrator's August 31, 2013 NAV was used as a partial basis for fair value measurement in the Company's September 30, 2013 balance sheet. The fund manager provides an estimate of the NAV at September 30, 2013 based on estimated performance. The Company adjusts fair value to the fund manager's estimated NAV that incorporates relevant valuation sources on a timely basis. To determine the reasonableness of the estimated NAV, the Company assesses the variance between the fund manager's estimated NAV and the fund administrator's NAV. Material variances are recorded in the current reporting period while immaterial variances are recorded in the following reporting period. Historically, our valuation estimates have not materially differed from the subsequent NAVs. The Flagstone investment fund administrators provide either monthly or quarterly reported NAVs with a one-month or one-quarter delay in valuation, respectively. As a result, the August 31, 2013 NAV or the June 30, 2013 NAV was used as a basis for fair value measurement in the Company's September 30, 2013 balance sheet. As these valuation techniques incorporate both observable and significant unobservable inputs, both the Paulson hedge funds and the Flagstone investment funds are classified as Level 3 assets. The Paulson hedge funds are subject to quarterly liquidity.
	Private equity investments
	Private equity investments consist of investments in three private equity funds assumed from the Flagstone Acquisition. The private equity investments respective fund administrator provides either monthly or quarterly NAVs with a one-month or one-quarter delay in valuation, respectively. As a result, the August 31, 2013 NAV or the June 30, 2013 NAV was used as a basis for fair value measurement in the Company's September 30, 2013 balance sheet. As this valuation technique incorporates both observable and significant unobservable inputs, the private equity investments are classified as Level 3 assets.
	Fund of hedge funds
	The fund of hedge funds includes a side pocket. While a redemption request has been submitted, the timing of receipt of proceeds on the side pocket is unknown. The fund's administrator provides a monthly reported NAV with a one-month delay in its valuation. As a result, the fund administrator's August 31, 2013 NAV was used as a basis for fair value measurement in the Company's September 30, 2013 balance sheet. The fund manager provides an estimate of the fund NAV at September 30, 2013 based on the estimated performance provided from the underlying funds. To determine the reasonableness of the NAV, the Company compares the one-month delayed fund administrator's NAV to the fund manager's estimated NAV that incorporates relevant valuation sources on a timely basis. Material variances are recorded in the current reporting period while immaterial variances are recorded in the following reporting period. As this valuation technique incorporates both observable and significant unobservable inputs, the fund of hedge funds is classified as a Level 3 asset.
	At September 30, 2013, the Company’s investments were allocated between Levels 1, 2 and 3 as follows:
		Level 1				Level 2				Level 3			Total
	U.S. government and government agency	$	—			$	1,320,483			$	—		$	1,320,483
	Non-U.S. government and government agency	—				403,997				—			403,997
	States, municipalities, political subdivision	—				43,929				—			43,929
	Agency residential mortgage-backed securities	—				320,201				—			320,201
	Non-agency residential mortgage-backed securities	—				23,131				—			23,131
	U.S. corporate	—				1,367,145				—			1,367,145
	Non-U.S. corporate	—				689,050				—			689,050
	Bank loans	—				736,458				—			736,458
	Catastrophe bonds	—				58,862				—			58,862
	Asset-backed securities	—				475,009				—			475,009
Total fixed maturities	—				5,438,265				—			5,438,265
Short-term investments	755,747				5,895				—			761,642
Other investments
Fund of hedge funds	—				—				2,450			2,450
Private equity investments	—				—				14,673			14,673
Hedge funds (a)	—				—				533,345			533,345
Mutual funds	—				9,004				—			9,004
Total other investments	—				9,004				550,468			559,472
Total	$	755,747			$	5,453,164			$	550,468		$	6,759,379
Noncontrolling interest (a)	(15,730		)		—				(465,472		)	(481,202		)
Total investments excluding noncontrolling interest	$	740,017			$	5,453,164			$	84,996		$	6,278,177
(a)	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
At December 31, 2012, the Company’s investments were allocated between Levels 1, 2 and 3 as follows:
	Level 1				Level 2				Level 3			Total
U.S. government and government agency	$	—			$	1,099,230			$	—		$	1,099,230
Non-U.S. government and government agency	—				302,279				—			302,279
States, municipalities, political subdivision	—				42,063				—			42,063
Agency residential mortgage-backed securities	—				388,874				—			388,874
Non-agency residential mortgage-backed securities	—				106,456				—			106,456
U.S. corporate	—				1,210,173				—			1,210,173
Non-U.S. corporate	—				593,265				—			593,265
Bank loans	—				673,383				—			673,383
Catastrophe bonds	—				56,947				—			56,947
Asset-backed securities	—				612,664				—			612,664
Total fixed maturities	—				5,085,334				—			5,085,334
Short-term investments	1,063,175				51,075				—			1,114,250
Other investments
Fund of hedge funds	—				—				4,757			4,757
Private equity investments	—				—				12,951			12,951
Hedge funds (a)	—				—				538,526			538,526
Mutual funds	—				8,214				—			8,214
Total other investments	—				8,214				556,234			564,448
Total	$	1,063,175			$	5,144,623			$	556,234		$	6,764,032
Noncontrolling interest (a)	—				—				(432,737		)	(432,737		)
Total investments excluding noncontrolling interest	$	1,063,175			$	5,144,623			$	123,497		$	6,331,295
(a)	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
At September 30, 2013, Level 3 investments excluding the noncontrolling interest totaled $84,996 (December 31, 2012: $123,497), representing 1.4% (December 31, 2012: 2.0%) of total investments, excluding noncontrolling interest, measured at fair value on a recurring basis.
The following tables present a reconciliation of the beginning and ending balances for all investments measured at fair value on a recurring basis using Level 3 inputs during the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended September 30, 2013				Three Months Ended September 30, 2012
		Total Fair Market Value				Total Fair Market Value
Level 3 investments - Beginning of period		$	505,158			$	454,793
Purchases		33,154				—
Sales		(35,264		)		(218		)
Net realized gains		4,503				13
Net unrealized gains		42,917				61,746
Transfers		—				921
Level 3 investments - End of period		$	550,468			$	517,255
Noncontrolling interest (a)		(465,472		)		(460,924		)
Level 3 investments excluding noncontrolling interest		$	84,996			$	56,331
		Nine Months Ended September 30, 2013				Nine Months Ended September 30, 2012
		Total Fair Market Value				Total Fair Market Value
Level 3 investments - Beginning of period		$	556,234			$	8,880
Purchases		98,669				500,000
Sales		(80,095		)		(1,115		)
Net realized gains		4,843				61
Net unrealized (losses) gains		(29,183		)		11,762
Transfers		—				(2,333		)
Level 3 investments - End of period		$	550,468			$	517,255
Noncontrolling interest (a)		(465,472		)		(460,924		)
Level 3 investments excluding noncontrolling interest		$	84,996			$	56,331
(a)	Includes Level 3 investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
There have not been any transfers between Levels 1 and 2 during the three and nine months ended September 30, 2013 or 2012. There have not been any transfers into or out of Level 3 during the three and nine months ended September 30, 2013. During the three months ended September 30, 2012, there was a transfer of an investment into Level 3 of the fair value hierarchy. This transfer was due to the conversion of a bank loan to other investments. During the three months ended June 30, 2012, there was a transfer of a private equity investment out of Level 3 “Other investments” to “Investments in affiliates.” Refer to Note 5 “Investments in affiliates.”

Investments_in_affilates

Investments in affilates	9 Months Ended
	Sep. 30, 2013
Equity Method Investments and Joint Ventures [Abstract]	'
Investments in affiliates	'
	Investments in affiliates
	(a) Operating affiliates
	AlphaCat Re 2011, Ltd.
	On May 25, 2011, the Company joined with other investors in capitalizing AlphaCat Re 2011, Ltd. ("AlphaCat Re 2011"), a special purpose reinsurer formed for the purpose of writing collateralized reinsurance and retrocessional reinsurance. At the time of formation, Validus Reinsurance, Ltd. ("Validus Re"), a wholly owned subsidiary of the Company, had a majority voting equity interest in AlphaCat Re 2011 and as a result, the financial statements of AlphaCat Re 2011 were included in the consolidated financial statements of the Company.
	On December 23, 2011, AlphaCat Re 2011 completed a secondary offering of its common shares to third party investors, along with a partial sale of Validus Re's common shares to one of the third party investors.
	As a result of these transactions, Validus Re maintained an equity interest in AlphaCat Re 2011, however its share of AlphaCat Re 2011's outstanding voting rights decreased to 43.7%. As a result of the Company's voting interest falling below 50%, the individual assets and liabilities and corresponding noncontrolling interest of AlphaCat Re 2011 were derecognized from the consolidated balance sheet of the Company as at December 31, 2011 and the remaining investment in AlphaCat Re 2011 has been treated as an equity method investment with effect from December 23, 2011.
	AlphaCat Re 2011 is now considered "off-risk" as the risk periods for all reinsurance contracts written by the company have expired. As a result, on January 4, 2013, January 23, 2013, May 1, 2013, May 28, 2013 and July 22, 2013 partial returns of investment were made to the investors of AlphaCat Re 2011. Validus Re's corresponding portion of the return of investment was $54,914.
	AlphaCat Re 2012, Ltd.
	On May 29, 2012, the Company joined with other investors in capitalizing AlphaCat Re 2012, Ltd. ("AlphaCat Re 2012"), a special purpose reinsurer formed for the purpose of writing collateralized reinsurance with a particular focus on windstorm risks for Florida domiciled insurance companies. The Company holds an equity interest of 37.9% and a voting interest of 49.0% in AlphaCat Re 2012, therefore the investment has been treated as an equity method investment.
	AlphaCat Re 2012 is now considered "off-risk" as the risk periods for all reinsurance contracts written by the company have expired. As a result, on February 22, 2013, June 20, 2013 and July 22, 2013, partial returns of investment were made to the investors of AlphaCat Re 2012. Validus Re's corresponding portion of the return of investment was $31,743.
	AlphaCat 2013, Ltd.
	On December 17, 2012, the Company joined with other investors in capitalizing AlphaCat 2013, Ltd. ("AlphaCat 2013"), a special purpose vehicle formed for the purpose of investing in collateralized reinsurance. The Company holds an equity interest of 19.7% and a voting interest of 40.9% in AlphaCat 2013, therefore the investment has been treated as an equity method investment.
	Investment in Insurance Linked Securities ("ILS")
	The Company received $219,400 of third party subscriptions in three of the AlphaCat ILS funds as of December 31, 2012. During the three and nine months ended September 30, 2013, the Company received $13,000 and $82,190 in additional third party subscriptions, respectively. The AlphaCat ILS funds invest in instruments with returns linked to property catastrophe reinsurance, retrocession and ILS contracts. Two of the funds are variable interest entities and are consolidated by the Company as Validus Re is deemed to be the primary beneficiary. The third fund is also a variable interest entity, however, it is not consolidated by the Company as Validus Re is not deemed to be the primary beneficiary. As a result, the investment in this fund is included in "Investments in affiliates" as at September 30, 2013. Income from this fund was $1,155 and $1,481 for the three and nine months ended September 30, 2013. The Company's carrying value of this fund amounted to $21,481 and $20,000 as at September 30, 2013 and December 31, 2012, respectively. The Company's maximum exposure to loss with respect to this investment is limited to the investment carrying value reported in the Company's Consolidated Balance Sheets.
	The following table presents a reconciliation of the beginning and ending investment in operating affiliates balances for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended September 30, 2013
		Investment in operating affiliates
		AlphaCat Re 2011			AlphaCat Re 2012				AlphaCat 2013				AlphaCat ILS funds			Total
	As at June 30, 2013	$	11,054		$	5,204			$	48,536			$	20,326		$	85,120
	Return of investment	(2,800		)	(4,550		)		—				—			(7,350		)
	(Loss) income from operating affiliates	(270		)	(7		)		585				1,155			1,463
	As at September 30, 2013	$	7,984		$	647			$	49,121			$	21,481		$	79,233
		Three Months Ended September 30, 2012
		Investment in operating affiliates
		AlphaCat Re 2011			AlphaCat Re 2012				Total
	As at June 30, 2012	$	59,238		$	27,252			$	86,490
	Income from operating affiliates	4,079			2,156				6,235
	As at September 30, 2012	$	63,317		$	29,408			$	92,725
		Nine Months Ended September 30, 2013
		Investment in operating affiliates
		AlphaCat Re 2011			AlphaCat Re 2012				AlphaCat 2013				AlphaCat ILS funds			Total
	As at December 31, 2012	$	62,792		$	29,319			$	45,000			$	20,000		$	157,111
	Return of investment	(54,914		)	(31,743		)		—				—			(86,657		)
	Income from operating affiliates	106			3,071				4,121				1,481			8,779
	As at September 30, 2013	$	7,984		$	647			$	49,121			$	21,481		$	79,233
		Nine Months Ended September 30, 2012
		Investment in operating affiliates
		AlphaCat Re 2011			AlphaCat Re 2012				Total
	As at December 31, 2011	$	53,031		$	—			$	53,031
	Purchase of shares	—			26,500				26,500
	Income from operating affiliates	10,286			2,908				13,194
	As at September 30, 2012	$	63,317		$	29,408			$	92,725
	The following table presents the Company's investments in operating affiliates as at September 30, 2013:
		Investment in operating affiliates
		Investment at cost			Voting ownership %			Equity ownership %			Carrying value
	AlphaCat Re 2011	$	8,254		43.7	%		22.3	%		$	7,984
	AlphaCat Re 2012	652			49	%		37.9	%		647
	AlphaCat 2013	45,000			40.9	%		19.7	%		49,121
	AlphaCat ILS Funds	20,000			—	%		9.1	%		21,481
	Total	$	73,906								$	79,233
	The following table presents the Company's investments in operating affiliates as at December 31, 2012:
		Investment in operating affiliates
		Investment at cost			Voting ownership %			Equity ownership %			Carrying value
	AlphaCat Re 2011	$	41,389		43.7	%		22.3	%		$	62,792
	AlphaCat Re 2012	26,500			49	%		37.9	%		29,319
	AlphaCat 2013	45,000			40.9	%		19.7	%		45,000
	AlphaCat ILS Fund	$	20,000		—	%		11.8	%		$	20,000
	Total	$	132,889								$	157,111
	(b) Investment affiliate
	Aquiline Financial Services Fund II L.P.
	On December 20, 2011, Validus Re entered into an Assignment and Assumption Agreement (the "Agreement") with Aquiline Capital Partners LLC, a Delaware limited liability company (the "Assignor") and Aquiline Capital Partners II GP (Offshore) Ltd., a Cayman Islands company limited by shares (the "General Partner") pursuant to which Validus Re has assumed 100% of the Assignor's interest in Aquiline Financial Services Fund II L.P. (the "Partnership") representing a total capital commitment of $50,000 (the "Commitment"), as a limited partner in the Partnership (the "Transferred Interest"). The Transferred Interest is governed by the terms of an Amended and Restated Exempted Limited Partnership Agreement dated as of July 2, 2010 (the "Limited Partnership Agreement"). Pursuant to the terms of the Limited Partnership Agreement, the Commitment will expire on July 2, 2015.
	The Partnership provides quarterly capital account statements with a three-month delay in its valuation. As a result, the Partnership's June 30, 2013 capital account statement was used as the basis for calculating the Company's share of partnership income for the period.
	The following table presents a reconciliation of the beginning and ending investment in the Company's investment affiliate balance for the three and nine months ended September 30, 2013 and 2012:
	Three Months Ended							Nine Months Ended
	September 30,			September 30,				September 30,				September 30,
	2013			2012				2013				2012
Investment affiliate, beginning of period	$	25,352		$	6,317			$	15,218			$	3,253
Capital contributions	6,185			430				13,089				5,328
Net unrealized (loss) on investments (a)	—			—				—				(1,436		)
Income (loss) from investment affiliate	1,044			(160		)		4,274				(558		)
Investment affiliate, end of period	$	32,581		$	6,587			$	32,581			$	6,587
(a)	Until March 31, 2012, this investment was included in " Other investments" as a level 3 investment in the fair value hierarchy, hence the change in fair value was included in net unrealized (losses) gains on investments.
The following table presents the Company's investment in the Partnership as at September 30, 2013:
	Investment in investment affiliate
	Investment at cost			Voting ownership %			Equity Ownership			Carrying Value
Aquiline Financial Services Fund II L.P	$	30,707		—	%		6.59	%		$	32,581

Noncontrolling_interest

Noncontrolling interest	9 Months Ended
	Sep. 30, 2013
Noncontrolling Interest [Abstract]	'
Noncontrolling interest	'
	Noncontrolling interest
	On April 2, 2012, the Company joined with other investors in capitalizing PaCRe, a new Class 4 Bermuda reinsurer formed for the purpose of writing high excess property catastrophe reinsurance. On May 1, 2013, PaCRe received additional capital contributions of $6,500 from Validus Re and $58,500 from a third party investor. Validus Re continues to have an equity interest of 10% and the remaining 90% interest is held by third party investors. Validus Re has a majority voting equity interest in PaCRe and as a result, the financial statements of PaCRe are included in the consolidated financial statements of the Company. The portion of PaCRe's earnings attributable to third party investors for the three and nine months ended September 30, 2013 and 2012 is recorded in the Consolidated Statements of Comprehensive Income as net (income) loss attributable to noncontrolling interest.
	The Company received $219,400 of third party subscriptions in three AlphaCat ILS funds as of December 31, 2012. During the three and nine months ended September 30, 2013, the Company received $13,000 and $82,190 in additional third party subscriptions, respectively. The AlphaCat ILS funds invest in instruments with returns linked to property catastrophe reinsurance, retrocession and ILS contracts. Two of the funds are variable interest entities and are consolidated by the Company as Validus Re is deemed to be the primary beneficiary. Validus Re has a majority participating interest in these two funds and as a result, the financial statements of these funds are included in the consolidated financial statements of the Company. The portion of these two funds' earnings attributable to third party investors for the three and nine months ended September 30, 2013 is recorded in the Consolidated Statements of Comprehensive Income within net (income) loss attributable to noncontrolling interest.
	The following table presents a reconciliation of the beginning and ending balances of noncontrolling interest for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended September 30, 2013
		PaCRe			AlphaCat ILS funds		Total
	As at June 30, 2013	$	427,755		$	70,690	$	498,445
	Purchase of shares by noncontrolling interest	—			13,000		13,000
	Net income attributable to noncontrolling interest	44,178			1,516		45,694
	As at September 30, 2013	$	471,933		$	85,206	$	557,139
		Three Months Ended September 30, 2012
		PaCRe			Total
	As at June 30, 2012	$	404,740		$	404,740
	Net income attributable to noncontrolling interest	56,746			56,746
	As at September 30, 2012	$	461,486		$	461,486
		Nine Months Ended September 30, 2013
		PaCRe			AlphaCat ILS funds		Total
	As at December 31, 2012	$	434,280		$	—	$	434,280
	Purchase of shares by noncontrolling interest	58,500			82,190		140,690
	Net (loss) income attributable to noncontrolling interest	(20,847		)	3,016		(17,831		)
	As at September 30, 2013	$	471,933		$	85,206	$	557,139
		Nine Months Ended September 30, 2012
		PaCRe			Total
	As at December 31, 2011	$	—		$	—
	Purchase of shares by noncontrolling interest	450,100			450,100
	Net income attributable to noncontrolling interest	11,386			11,386
	As at September 30, 2012	$	461,486		$	461,486

Derivative_instruments

Derivative instruments	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative instruments	'
	Derivative instruments
	The Company enters into derivative instruments for risk management purposes, specifically to hedge unmatched foreign currency exposures and interest rate exposures. As at September 30, 2013, the Company held foreign currency forward contracts to mitigate the risk of fluctuations in the Euro, Chilean Peso, Australian Dollar, New Zealand Dollar and British Pound Sterling to U.S. dollar exchange rates. As at September 30, 2013, the Company held two interest rate swap contracts to mitigate the risk of interest rate exposure on the payment of interest on the Company's 2006 and 2007 Junior Subordinated Deferrable Debentures, as well as three interest rate swaps and one cross-currency interest rate swap to mitigate the risk of interest rate and foreign exchange rate exposure on the payment of interest on Flagstone's 2006 and 2007 Junior Subordinated Deferrable Debentures.
	As part of the Flagstone Acquisition, the Company assumed foreign currency forward contracts which were not designated as hedging instruments. The contracts expired on July 15, 2013.
	The following table summarizes information on the location and amount of the fair value of derivatives not designated as hedging instruments on the consolidated balance sheet at September 30, 2013 and December 31, 2012:
			At September 30, 2013									At December 31, 2012
	Derivatives not designated as hedging instruments:		Net notional exposure			Asset Derivative at Fair Value (a)			Liability Derivative at Fair Value (a)			Net notional exposure			Asset Derivative at Fair Value (a)		Liability Derivative at Fair Value (a)
	Currency swaps		$	—		$	—		$	—		$	17,153		$	—	$	772
	Foreign currency forward contracts		$	—		$	—		$	—		$	310,541		$	—	$	394
	(a)	Asset and liability derivatives are classified within other assets and accounts payable and accrued expenses respectively on the Consolidated Balance Sheets.
	The following table summarizes information on the location and amount of the fair value of derivatives designated as hedging instruments on the consolidated balance sheets at September 30, 2013 and December 31, 2012:
			At September 30, 2013									At December 31, 2012
	Derivatives designated as hedging instruments:		Net notional exposure			Asset Derivative at Fair Value (a)			Liability Derivative at Fair Value (a)			Net notional exposure			Asset Derivative at Fair Value (a)		Liability Derivative at Fair Value (a)
	Foreign currency forward contracts		$	168,722		$	4,977		$	1,115		$	35,976		$	—	$	223
	Interest rate swap contracts		$	552,263		$	—		873			$	289,800		$	—	$	220
	(a)	Asset and liability derivatives are classified within other assets and accounts payable and accrued expenses respectively on the Consolidated Balance Sheets.
	(a)    Classification within the fair value hierarchy
	As described in Note 4: "Fair value measurements," under U.S. GAAP, a company must determine the appropriate level in the fair value hierarchy for each fair value measurement. The assumptions used within the valuation are observable in the marketplace, can be derived from observable data or are supported by observable levels at which other similar transactions are executed in the marketplace. Accordingly, these derivatives were classified within Level 2 of the fair value hierarchy.
	(b)Derivative instruments designated as a fair value hedge
	The Company designates its foreign currency forward contract derivative instruments as fair value hedges and formally and contemporaneously documents all relationships between the hedging instruments and hedged items and links the hedging derivatives to specific assets or liabilities. The Company assesses the effectiveness of the hedges, both at inception and on an on-going basis and determines whether the hedges are highly effective in offsetting changes in fair value of the linked hedged items.
	The following table provides the total impact on earnings relating to the derivative instruments formally designated as fair value hedges along with the impact of the related hedged items for the three and nine months ended September 30, 2013 and 2012:
	Foreign currency forward contracts		Three Months Ended September 30, 2013			Three Months Ended September 30, 2012			Nine Months Ended September 30, 2013			Nine Months Ended September 30, 2012
	Amount of gain (loss) recognized in income on derivative		$	3,116		$	1,749		$	2,670		$	130
	Amount of gain (loss) on hedged item recognized in income attributable to risk being hedged		$	(3,116	)	$	(1,749	)	$	(2,670	)	$	(130	)
	Amount of gain (loss) recognized in income on derivative (ineffective portion)		$	—		$	—		$	—		$	—
	The gain (loss) is recognized in income within foreign exchange gains (losses).
	(c)    Derivative instruments designated as a cash flow hedge
	The Company designates its interest rate derivative instruments as cash flow hedges and formally and contemporaneously documents all relationships between the hedging instruments and hedged items and links the hedging derivatives to specific assets and liabilities. The Company assesses the effectiveness of the hedges, both at inception and on an on-going basis (as required) and determines whether the hedges are highly effective in offsetting changes in fair value of the linked hedged items. The Company currently applies the long haul method when assessing the hedge's effectiveness.
	The following table provides the total impact on other comprehensive income and earnings relating to the derivative instruments formally designated as cash flow hedges along with the impact of the related hedged items for the three and nine months ended September 30, 2013:
	Interest rate swap contracts		Three Months Ended September 30, 2013			Three Months Ended September 30, 2012			Nine Months Ended September 30, 2013			Nine Months Ended September 30, 2012
	Amount of effective portion recognized in other comprehensive income		$	3,268		$	195		$	7,838		$	195
	Amount of effective portion subsequently reclassified to earnings		$	(3,268	)	$	(195	)	$	(7,838	)	$	(195	)
	Amount of ineffective portion excluded from effectiveness testing		$	—		$	—		$	—		$	—
	The above balances relate to interest paid and have been classified as finance expenses in the consolidated statements of comprehensive income. There was no interest rate swap contract activity for the three and nine months ended September 30, 2012.
	(d)    Balance sheet offsetting
	There was no balance sheet offsetting activity as at September 30, 2013 or December 31, 2012.
	The Company currently provides cash collateral as security for interest rate swap contracts. The Company does not provide cash collateral or financial instruments as security for foreign currency forward contracts. Our derivative instruments are generally traded under International Swaps and Derivatives Association master netting agreements, which establish terms that apply to all transactions. On a periodic basis, the amounts receivable from or payable to the counterparties are settled in cash. The Company has not elected to settle multiple transactions with an individual counterparty on a net basis.

Reserve_for_losses_and_loss_ex

Reserve for losses and loss expenses	9 Months Ended
	Sep. 30, 2013
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]	'
Reserve for losses and loss expenses	'
	Reserve for losses and loss expenses
	Reserves for losses and loss expenses are based in part upon the estimation of case reserves reported from brokers, insureds and ceding companies. The Company also uses statistical and actuarial methods to estimate ultimate expected losses and loss expenses. The period of time from the occurrence of a loss to the reporting of a loss to the Company and to the settlement of the Company's liability may be several months or years. During this period, additional facts and trends may be revealed. As these factors become apparent, reserves will be adjusted, sometimes requiring an increase or decrease in the overall reserves of the Company, and at other times requiring a reallocation of incurred but not reported reserves to specific case reserves. These estimates are reviewed and adjusted regularly, and such adjustments, if any, are reflected in earnings in the period in which they become known. While management believes that it has made a reasonable estimate of ultimate losses, there can be no assurances that ultimate losses and loss expenses will not exceed this estimate.
	The following table represents an analysis of paid and unpaid losses and loss expenses incurred and a reconciliation of the beginning and ending unpaid losses and loss expenses for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended						Nine Months Ended
		September 30,			September 30,			September 30,			September 30,
		2013			2012			2013			2012
	Reserve for losses and loss expenses, beginning of period	$	3,283,450		$	2,591,299		$	3,517,573		$	2,631,143
	Losses and loss expenses recoverable	(418,693		)	(371,484		)	(439,967		)	(372,485		)
	Net reserves for losses and loss expenses, beginning of period	2,864,757			2,219,815			3,077,606			2,258,658
	Net reserves acquired	—			—			948			—
	Increase (decrease) in net losses and loss expenses incurred in respect of losses occurring in:
	Current year	243,015			205,219			759,617			658,884
	Prior years	(65,050		)	(49,764		)	(171,837		)	(117,748		)
	Total incurred losses and loss expenses	177,965			155,455			587,780			541,136
	Total net paid losses	(274,868		)	(144,628		)	(847,192		)	(569,380		)
	Foreign exchange	34,363			14,710			(16,925		)	14,938
	Net reserve for losses and loss expenses, end of period	2,802,217			2,245,352			2,802,217			2,245,352
	Losses and loss expenses recoverable	421,518			317,252			421,518			317,252
	Reserve for losses and loss expenses, end of period	$	3,223,735		$	2,562,604		$	3,223,735		$	2,562,604

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2013
Reinsurance Disclosures [Abstract]	'
Reinsurance	'
	Reinsurance
	The Company enters into reinsurance and retrocession agreements in order to mitigate its accumulation of loss, reduce its liability on individual risks, enable it to underwrite policies with higher limits and increase its aggregate capacity. The cession of insurance and reinsurance does not legally discharge the Company from its primary liability for the full amount of the policies, and the Company is required to pay the loss and bear collection risk if the reinsurer fails to meet its obligations under the reinsurance or retrocession agreement. Amounts recoverable from reinsurers are estimated in a manner consistent with the underlying liabilities.
	Credit risk
	The Company evaluates the financial condition of its reinsurers and monitors concentration of credit risk arising from its exposure to individual reinsurers. The reinsurance program is generally placed with reinsurers whose rating, at the time of placement, was A- or better by Standard & Poor's or the equivalent with other rating agencies. Exposure to a single reinsurer is also controlled with restrictions dependent on rating. At September 30, 2013, 97.7% (December 31, 2012: 97.9%) of reinsurance recoverables (which includes loss reserves recoverable and recoverables on paid losses) were fully collateralized or from reinsurers rated A- or better and included $211,864 of total IBNR recoverable (December 31, 2012: $185,255). Reinsurance recoverables by reinsurer are as follows:
		September 30, 2013					December 31, 2012
		Reinsurance Recoverable			% of Total		Reinsurance Recoverable		% of Total
	Top 10 reinsurers	$	340,988		75.5	%	$	360,234	74.1	%
	Other reinsurers’ balances > $1 million	102,714			22.7	%	115,262		23.7	%
	Other reinsurers’ balances < $1 million	7,890			1.8	%	10,906		2.2	%
	Total	$	451,592		100	%	$	486,402	100	%
			September 30, 2013
	Top 10 Reinsurers		Rating	Reinsurance Recoverable			% of Total
	Lloyd's Syndicates		A+	$	74,586		21.9	%
	Everest Re		A+	52,372			15.3	%
	National Indemnity		AA+	50,984			14.9	%
	Hannover Re		AA-	45,975			13.5	%
	Fully Collateralized		NR	34,293			10.1	%
	Swiss Re		AA-	20,728			6.1	%
	Third Point Reinsurance Ltd		A-	20,049			5.9	%
	Transatlantic Re		A+	15,887			4.7	%
	XL Re		A	14,062			4.1	%
	Munich Re		AA-	12,052			3.5	%
	Total			$	340,988		100	%
			December 31, 2012
	Top 10 Reinsurers		Rating	Reinsurance Recoverable			% of Total
	Lloyd’s Syndicates		A+	$	71,469		19.9	%
	National Indemnity		AA+	59,941			16.6	%
	Everest Re		A+	51,340			14.3	%
	Fully Collateralized		NR	47,445			13.2	%
	Hannover Re		AA-	40,552			11.3	%
	Munich Re		AA-	20,954			5.8	%
	Transatlantic Re		A+	20,320			5.6	%
	Swiss Re		AA-	16,992			4.7	%
	Allianz		AA-	16,367			4.5	%
	XL Re		A	14,854			4.1	%
	Total			$	360,234		100	%
	NR: Not rated
	At September 30, 2013 and December 31, 2012, the provision for uncollectible reinsurance relating to losses recoverable was $6,209 and $6,602, respectively. To estimate the provision for uncollectible reinsurance recoverable, the reinsurance recoverable is first allocated to applicable reinsurers. This determination is based on a process rather than an estimate, although an element of judgment is applied. As part of this process, ceded IBNR is allocated by reinsurer. The Company uses a default analysis to estimate uncollectible reinsurance. The primary components of the default analysis are reinsurance recoverable balances by reinsurer and default factors used to determine the portion of a reinsurer's balance deemed to be uncollectible. Default factors require considerable judgment and are determined using the current rating, or rating equivalent, of each reinsurer as well as other key considerations and assumptions.
	Of the $451,592 reinsurance recoverable at September 30, 2013 (December 31, 2012: $486,402), $34,293 was fully collateralized (December 31, 2012: $47,445).

Share_capital

Share capital	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity Note [Abstract]	'
Share capital	'
	Share capital
	(a)	Authorized and issued
	The Company’s authorized share capital is 571,428,571 common shares with a par value of $0.175 per share. The holders of common shares are entitled to receive dividends. Holders of common shares are allocated one vote per share, provided that, if the controlled shares of any shareholder or group of related shareholders constitute more than 9.09 percent of the outstanding common shares of the Company, their voting power will be reduced to 9.09 percent.
	The Company may from time to time repurchase its securities, including common shares, Junior Subordinated Deferrable Debentures and Senior Notes. On February 6, 2013, the Board of Directors of the Company approved an increase in the Company's common share purchase authorization to $500,000. This amount is in addition to the $1,206,845 of common shares repurchased by the Company through February 6, 2013 under its previously authorized share repurchase programs.
	There were no additional share repurchases during the three months ended September 30, 2013. The Company has repurchased 52,849,445 common shares for an aggregate purchase price of $1,564,029 from the inception of its share repurchase program to September 30, 2013. The Company had $142,816 remaining under its authorized share repurchase program as of September 30, 2013.
	The Company expects the purchases under its share repurchase program to be made from time to time in the open market or in privately negotiated transactions. The timing, form and amount of the share repurchases under the program will depend on a variety of factors, including market conditions, the Company’s capital position relative to internal and rating agency targets, legal requirements and other factors. The repurchase program may be modified, extended or terminated by the Board of Directors at any time.
	On November 30, 2012, the Company acquired all of the outstanding shares of Flagstone from a group of institutional and other investors. Pursuant to the merger agreement, the Company acquired all of Flagstone's outstanding common shares in exchange for the Company's common shares and cash. The Company issued 14,202,664 common shares, net of 87,725 shares withheld for income taxes, valued at $34.87 per share as partial consideration for the acquisition. In addition, 1,638,875 common shares recorded in treasury are owned by Flagstone (Bermuda) Holdings Limited, a wholly-owned subsidiary of Validus Holdings, Ltd. As part of the Flagstone Acquisition, warrants to acquire Flagstone shares were converted into 121,942 warrants to acquire the Company's common shares. In accordance with the merger agreement, these warrants have a $62.02 strike price and expire on December 31, 2013.
	The following table is a summary of the common shares issued and outstanding:
		Common Shares
	Common shares issued, December 31, 2012	152,698,191
	Restricted share awards vested, net of shares withheld	768,889
	Restricted share units vested, net of shares withheld	14,381
	Options exercised	277,615
	Warrants exercised	591,480
	Direct issuance of common stock	928
	Performance share awards vested, net of shares withheld	31,897
	Deferred share units vested, net of shares withheld	2,935
	Common shares issued, September 30, 2013	154,386,316
	Shares repurchased, September 30, 2013	(54,488,320	)
	Common shares outstanding, September 30, 2013	99,897,996
		Common Shares
	Common shares issued, December 31, 2011	134,503,065
	Restricted share awards vested, net of shares withheld	1,545,024
	Restricted share units vested, net of shares withheld	15,173
	Options exercised	439,065
	Warrants exercised	130,121
	Common shares issued, September 30, 2012	136,632,448
	Shares repurchased, September 30, 2012	(43,138,057	)
	Common shares outstanding, September 30, 2012	93,494,391
	(b)	Warrants
	During the three months ended September 30, 2013, 163,772 warrants were exercised which resulted in the issuance of 83,287 common shares. During the nine months ended September 30, 2013, 1,114,416 warrants were exercised which resulted in the issuance of 591,480 common shares. During the three and nine months ended September 30, 2012, 264,127 warrants were exercised which resulted in the issuance of 130,121 shares. Holders of the outstanding warrants are entitled to exercise the warrants in whole or in part at any time until the expiration date. The total outstanding warrants at September 30, 2013 were 5,296,056 (December 31, 2012: 6,410,472). No further warrants are anticipated to be issued.
	(c)	Deferred share units
	Under the terms of the Company’s Director Stock Compensation Plan, non-management directors may elect to receive their director fees in deferred share units rather than cash.  The number of share units distributed in case of election under the plan is equal to the amount of the annual retainer fee otherwise payable to the director on such payment date divided by 100% of the fair market value of a share on such payment date. Additional deferred share units are issued in lieu of dividends that accrue on these deferred share units.  There were no outstanding deferred share units at September 30, 2013 (December 31, 2012: 5,001).
	As of February 16, 2013, John Hendrickson became an employee director. As a result, his 5,039 deferred share units vested and 2,935 common shares were issued to him, net of shares withheld for taxes.
	(d)	Dividends
	On February 6, 2013, the Company announced a special dividend in the amount of $2.00 per common share and $2.00 per common share equivalent for which each outstanding warrant is exercisable (the "2013 Special Dividend"). The 2013 Special Dividend was paid on February 26, 2013 to shareholders and warrant holders of record as of February 19, 2013.
	In addition, the Company announced a quarterly cash dividend of $0.30 (2012: $0.25) per common share and $0.30 per common share equivalent for which each outstanding warrant is exercisable. This dividend was paid on March 29, 2013 to holders of record on March 15, 2013.
	On May 1, 2013, the Company announced a quarterly cash dividend of $0.30 (2012: $0.25) per common share and $0.30 per common share equivalent for which each outstanding warrant is exercisable. This dividend was paid on June 28, 2013 to holders of record on June 14, 2013.
	On July 30, 2013, the Company announced a quarterly cash dividend of $0.30 (2012: $0.25) per common share and $0.30 per common share equivalent for which each outstanding warrant is exercisable. This dividend was paid on September 30, 2013 to holders of record on September 13, 2013.

Stock_plans

Stock plans	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock plans	'
	Stock plans
	Long Term Incentive Plan and Short Term Incentive Plan
	The Company’s Amended and Restated 2005 Long Term Incentive Plan (“LTIP”) provides for grants to employees of options, stock appreciation rights (“SARs”), restricted shares, restricted share units, performance shares, dividend equivalents or other share-based awards. In addition, the Company may issue restricted share awards or restricted share units in connection with awards issued under its annual Short Term Incentive Plan (“STIP”). The total number of shares reserved for issuance under the LTIP and STIP are 13,126,896 shares of which 1,783,462 shares are remaining. The LTIP and STIP are administered by the Compensation Committee of the Board of Directors. No SARs have been granted to date. Grant prices are established at the fair market value of the Company’s common shares at the date of grant.
	i.Options
	Options may be exercised for voting common shares upon vesting. Options have a life of 10 years and vest either ratably or at the end of the required service period from the date of grant. Fair value of the option awards at the date of grant is determined using the Black-Scholes option-pricing model.
	Expected volatility is based on stock price volatility of comparable publicly-traded companies. The Company used the simplified method consistent with U.S. GAAP authoritative guidance on stock compensation expenses to estimate expected lives for options granted during the period as historical exercise data was not available and the options met the requirement as set out in the guidance.
	The Company has not granted any stock options since September 4, 2009.
	Share compensation expenses in respect of options of $nil were recorded for the three months ended September 30, 2013 (2012: $nil). Share compensation expenses in respect of options of $nil were recorded for the nine months ended September 30, 2013 (2012: $142). The expenses represent the proportionate accrual of the fair value of each grant based on the remaining vesting period.
	A modification event was triggered as a result of the 2013 Special Dividend. In accordance with the terms of the LTIP under which the options were issued, an adjustment was required to protect the holders of such stock options from changes in the value of the stock options following the declaration of the 2013 Special Dividend. The modification of the options included a decrease in the exercise price of each stock option and an increase in the number of shares underlying each stock option. The fair value of the options before and after the modification was unchanged.
	Activity with respect to options for the nine months ended September 30, 2013 was as follows:
		Options		Weighted Average Grant Date Fair Value			Weighted Average Grant Date Exercise Price
	Options outstanding, December 31, 2012	1,823,947		$	6.52		$	20.69
	Options regranted (modified)	1,833,414		6.76			19.02
	Options exercised	(277,615	)	5.24			23.58
	Options cancelled (modified)	(1,733,139	)	6.76			20.12
	Options outstanding, September 30, 2013	1,646,607		$	6.75		$	18.94
	Options exercisable, September 30, 2013	1,646,607		$	6.75		$	18.94
	Activity with respect to options for the nine months ended September 30, 2012 was as follows:
		Options		Weighted Average Grant Date Fair Value			Weighted Average Grant Date Exercise Price
	Options outstanding, December 31, 2011	2,263,012		$	6.69		$	20.12
	Options exercised	(439,065	)	7.44			17.73
	Options outstanding, September 30, 2012	1,823,947		$	6.52		$	20.69
	Options exercisable, September 30, 2012	1,823,947		$	6.52		$	20.69
	ii.Restricted share awards
	Restricted shares granted under the LTIP and STIP vest either pro rata or at the end of the required service period and contain certain restrictions during the vesting period, relating to, among other things, forfeiture in the event of termination of employment and transferability. Share compensation expenses of $10,041 were recorded for the three months ended September 30, 2013 (2012: $6,626). Share compensation expenses of $20,035 were recorded for the nine months ended September 30, 2013 (2012: $18,742). The expenses represent the proportionate accrual of the fair value of each grant based on the remaining vesting period.
	Activity with respect to unvested restricted share awards for the nine months ended September 30, 2013 was as follows:
		Restricted Share Awards		Weighted Average Grant Date Fair Value
	Restricted share awards outstanding, December 31, 2012	2,170,547		$	29.24
	Restricted share awards granted	1,580,117		36.06
	Restricted share awards vested	(930,296	)	28.08
	Restricted share awards forfeited	(110,912	)	28.34
	Restricted share awards outstanding, September 30, 2013	2,709,456		$	33.65
	Activity with respect to unvested restricted share awards for the nine months ended September 30, 2012 was as follows:
		Restricted Share Awards		Weighted Average Grant Date Fair Value
	Restricted share awards outstanding, December 31, 2011	3,003,547		$	25.77
	Restricted share awards granted	901,506		31.38
	Restricted share awards vested	(1,678,905	)	24.36
	Restricted share awards forfeited	(30,801	)	28.1
	Restricted share awards outstanding, September 30, 2012	2,195,347		$	29.12
	At September 30, 2013, there were $76,084 (December 31, 2012: $43,952) of total unrecognized share compensation expenses in respect of restricted share awards that are expected to be recognized over a weighted-average period of 3.4 years (December 31, 2012: 2.6 years ).
	iii.Restricted share units
	Restricted share units under the LTIP and STIP vest either ratably or at the end of the required service period and contain certain restrictions during the vesting period, relating to, among other things, forfeiture in the event of termination of employment and transferability. Share compensation expenses of $168 were recorded for the three months ended September 30, 2013 (2012: $132). Share compensation expenses of $419 were recorded for the nine months ended September 30, 2013 (2012: $363). The expenses represent the proportionate accrual of the fair value of each grant based on the remaining vesting period.
	Activity with respect to unvested restricted share units for the nine months ended September 30, 2013 was as follows:
		Restricted Share Units		Weighted Average Grant Date Fair Value
	Restricted share units outstanding, December 31, 2012	47,238		$	29.61
	Restricted share units granted	36,635		36.11
	Restricted share units vested	(21,814	)	28.17
	Restricted share units issued in lieu of cash dividends	3,924		30.29
	Restricted share units outstanding, September 30, 2013	65,983		$	33.74
	Activity with respect to unvested restricted share units for the nine months ended September 30, 2012 was as follows:
		Restricted Share Units		Weighted Average Grant Date Fair Value
	Restricted share units outstanding, December 31, 2011	53,312		$	27.6
	Restricted share units granted	16,633		31.77
	Restricted share units vested	(22,818	)	26.49
	Restricted share units issued in lieu of cash dividends	1,162		28.36
	Restricted share units forfeited	(1,393	)	28.57
	Restricted share units outstanding, September 30, 2012	46,896		$	29.61
	At September 30, 2013, there were $1,839 (December 31, 2012: $978) of total unrecognized share compensation expenses in respect of restricted share units that are expected to be recognized over a weighted-average period of 3.5 years (December 31, 2012: 2.6 years).
	iv.Performance share awards
	The performance share awards contain a performance based component. The performance component relates to the compounded growth in the Dividend Adjusted Diluted Book Value per Share (“DBVPS”) over a three year period. For performance share awards granted during the period, the grant date Diluted Book Value per Share is based on the DBVPS at the end of the most recent financial reporting year. The Dividend Adjusted Performance Period End DBVPS will be the DBVPS three years after the grant date DBVPS. The fair value estimate earns over the requisite attribution period and the estimate will be reassessed at the end of each performance period which will reflect any adjustments in the consolidated statements of comprehensive income in the period in which they are determined.
	Share compensation expenses of $318 were recorded for the three months ended September 30, 2013 (2012: $587). Share compensation expenses of ($971) were recorded for the nine months ended September 30, 2013 (2012: $336). The negative expense is due to a reversal of expenses on unvested performance share awards based on a review of current and projected performance criteria.
	Activity with respect to unvested performance share awards for the nine months ended September 30, 2013 was as follows:
		Performance Share Awards		Weighted Average Grant Date Fair Value
Performance share awards outstanding, December 31, 2012	220,845		$	31.81
Performance share awards granted	38,386		36.11
Performance share awards vested	(39,094	)	28.7
Performance share awards forfeited	(18,701	)	31.05
Performance share awards conversion adjustment	(99,616	)	$	33.05
Performance share awards outstanding, September 30, 2013	101,820		$	33.56
Activity with respect to unvested performance share awards for the nine months ended September 30, 2012 was as follows:
	Performance Share Awards		Weighted Average Grant Date Fair Value
Performance share awards outstanding, December 31, 2011	279,019		$	30.77
Performance share awards granted	41,128		31.38
Performance share awards forfeited	(99,302	)	28.7
Performance share awards outstanding, September 30, 2012	220,845		$	31.81
At September 30, 2013, there were $1,893 (December 31, 2012: $3,328) of total unrecognized share compensation expenses in respect of performance share awards that are expected to be recognized over a weighted-average period of 2.2 years (December 31, 2012: 1.7 years).
Total share compensation expenses
The breakdown of share compensation expenses by award type was as follows:
	Three Months Ended						Nine Months Ended
	September 30,			September 30,			September 30,			September 30,
	2013			2012			2013			2012
Options	$	—		$	—		$	—		$	142
Restricted share awards	10,041			6,626			20,035			18,742
Restricted share units	168			132			419			363
Performance share awards	318			587			(971		)	336
Total	$	10,527		$	7,345		$	19,483		$	19,583

Debt_and_financing_arrangement

Debt and financing arrangements	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Debt and financing arrangements	'
	Debt and financing arrangements
	(a)	Financing structure and finance expenses
	The financing structure at September 30, 2013 was:
		Commitment		Outstanding (a)			Drawn
	2006 Junior Subordinated Deferrable Debentures	$	150,000	$	150,000		$	150,000
	2007 Junior Subordinated Deferrable Debentures	200,000		139,800			139,800
	2010 Senior Notes due 2040	250,000		250,000			247,171
	$400,000 syndicated unsecured letter of credit facility	400,000		—			—
	$525,000 syndicated secured letter of credit facility	525,000		371,990			—
	$200,000 bi-lateral secured letter of credit facility	200,000		77,626			—
	Talbot FAL Facility (b)	25,000		25,000			—
	PaCRe senior secured letter of credit facility	10,000		258			—
	IPC bi-lateral facility	40,000		26,019			—
	$375,000 Flagstone bi-lateral facility	375,000		297,996			—
	Flagstone 2006 Junior Subordinated Deferrable Debentures	137,577		137,577			137,577
	Flagstone 2007 Junior Subordinated Deferrable Debentures	113,750		113,750			113,750
	Total	$	2,426,327	$	1,590,016		$	788,298
	The financing structure at December 31, 2012 was:
		Commitment		Outstanding (a)			Drawn
	2006 Junior Subordinated Deferrable Debentures	$	150,000	$	150,000		$	150,000
	2007 Junior Subordinated Deferrable Debentures	200,000		139,800			139,800
	2010 Senior Notes due 2040	250,000		250,000			247,090
	$400,000 syndicated unsecured letter of credit facility	400,000		—			—
	$525,000 syndicated secured letter of credit facility	525,000		376,570			—
	$500,000 secured letter of credit facility	500,000		92,402			—
	Talbot FAL Facility (b)	25,000		25,000			—
	PaCRe senior secured letter of credit facility	10,000		219			—
	IPC bi-lateral facility	80,000		40,613			—
	$550,000 Flagstone bi-lateral facility	550,000		381,019			—
	Flagstone 2006 Junior Subordinated Deferrable Debentures	137,159		137,159			137,159
	Flagstone 2007 Junior Subordinated Deferrable Debentures	113,750		113,750			113,750
	Total	$	2,940,909	$	1,706,532		$	787,799
	(a)	Indicates utilization of commitment amount, not drawn borrowings.
	(b)	Talbot operates in the Lloyd’s market ("Lloyds") through a corporate member, Talbot 2002 Underwriting Capital Ltd (“T02”), which is the sole participant in Syndicate 1183. Lloyd’s sets T02’s required capital annually based on Syndicate 1183’s business plan, rating environment, reserving environment together with input arising from Lloyd’s discussions with, inter alia, regulatory and rating agencies.  Such capital, called Funds at Lloyd’s (“FAL”), comprises: cash, investments and undrawn letters of credit provided by various banks.
	Finance expenses consist of interest on our junior subordinated deferrable debentures, senior notes, variable funding notes, the amortization of debt offering costs, fees relating to our credit facilities, bank charges and the costs of FAL as follows:
		Three Months Ended					Nine Months Ended
		September 30,		September 30,			September 30,		September 30,
		2013		2012			2013		2012
	2006 Junior Subordinated Deferrable Debentures	$	2,235	$	1,628		$	6,633	$	4,729
	2007 Junior Subordinated Deferrable Debentures	1,848		1,211			5,492		7,072
	2010 Senior Notes due 2040	5,597		5,597			16,792		16,792
	Variable Funding Notes (a)	11,893		—			44,562		—
	Flagstone 2006 Junior Subordinated Deferrable Debentures	2,285		—			5,988		—
	Flagstone 2007 Junior Subordinated Deferrable Debentures	1,807		—			4,426		—
	Credit facilities	1,248		948			5,001		10,530
	Bank charges	187		(52		)	419		131
	Talbot FAL Facility	32		30			95		93
	Total	$	27,132	$	9,362		$	89,408	$	39,347
	(a)	Includes variable funding note expense and other AlphaCat related fees. Refer to Note 13: "Variable funding notes" for further details.
	(b)	$250,000 2010 Senior Notes due 2040
	On January 21, 2010, the Company offered and sold $250,000 of Senior Notes due 2040 (the “2010 Senior Notes”) in a registered public offering. The 2010 Senior Notes mature on January 26, 2040, and are redeemable at the Company’s option in whole any time or in part from time to time at a make-whole redemption price. The Company may redeem the notes in whole, but not in part, at any time upon the occurrence of certain tax events as described in the prospectus supplement of the 2010 Senior Notes. The 2010 Senior Notes bear interest at the rate of 8.875% per annum from January 26, 2010 to maturity or early redemption. Interest on the 2010 Senior Notes is payable semi-annually in arrears on January 26 and July 26 of each year, commencing on July 26, 2010.  The net proceeds of $243,967 from the sale of the 2010 Senior Notes, after the deduction of commissions paid to the underwriters in the transaction and other expenses, was used by the Company for general corporate purposes, which included the repurchase of its outstanding capital stock and payment of dividends to shareholders. Debt issuance costs of $2,808 were deferred as an asset and amortized over the life of the 2010 Senior Notes. There were no redemptions made during the nine months ended September 30, 2013 and 2012.
	The 2010 Senior Notes are unsecured and unsubordinated obligations of the Company and rank equally in right of payment with all of the Company’s existing and future unsecured and unsubordinated indebtedness.  The 2010 Senior Notes will be effectively junior to all of the Company’s future secured debt, to the extent of the value of the collateral securing such debt, and will rank senior to all our existing and future subordinated debt.  The 2010 Senior Notes are structurally subordinated to all obligations of the Company’s subsidiaries.
	Future expected payments of principal on the 2010 Senior Notes are as follows:
	2013	$	—
	2014	—
	2015	—
	2016	—
	2017 and thereafter	250,000
	Total minimum future payments	$	250,000
	(c)	Junior subordinated deferrable debentures
	On June 15, 2006, the Company participated in a private placement of $150,000 of junior subordinated deferrable interest debentures due 2036 (the “2006 Junior Subordinated Deferrable Debentures”). The 2006 Junior Subordinated Deferrable Debentures mature on June 15, 2036, are redeemable at the Company’s option at par as of June 15, 2011, and require quarterly interest payments by the Company to the holders of the 2006 Junior Subordinated Deferrable Debentures. Interest was payable at 9.069% per annum through June 15, 2011, and thereafter at a floating rate of three-month LIBOR plus 355 basis points, reset quarterly. The proceeds of $150,000 from the sale of the 2006 Junior Subordinated Deferrable Debentures, after the deduction of commissions paid to the placement agents in the transaction and other expenses, were used by the Company to fund Validus Re segment operations and for general working capital purposes. Debt issuance costs of $3,750 were deferred as an asset and were amortized to income over the five year optional redemption period. There were no redemptions made during the nine months ended September 30, 2013 and 2012.
	On June 21, 2007, the Company participated in a private placement of $200,000 of junior subordinated deferrable interest debentures due 2037 (the “2007 Junior Subordinated Deferrable Debentures”). The 2007 Junior Subordinated Deferrable Debentures mature on June 15, 2037, are redeemable at the Company’s option at par as of June 15, 2012, and require quarterly interest payments by the Company to the holders of the 2007 Junior Subordinated Deferrable Debentures. Interest was payable at 8.480% per annum through June 15, 2012, and thereafter at a floating rate of three-month LIBOR plus 295 basis points, reset quarterly. The proceeds of $200,000 from the sale of the 2007 Junior Subordinated Deferrable Debentures, after the deduction of commissions paid to the placement agents in the transaction and other expenses, were used by the Company to fund the purchase of Talbot Holdings Ltd. Debt issuance costs of $2,000 were deferred as an asset and were amortized to income over the five year optional redemption period. There were no redemptions made during the nine months ended September 30, 2013 and 2012.
	As part of the Flagstone Acquisition, the Company assumed $137,577 of junior subordinated deferrable debentures due 2036 (the “Flagstone 2006 Junior Subordinated Deferrable Debentures”). The Flagstone 2006 Junior Subordinated Deferrable Debentures mature on September 15, 2036, are redeemable at the Company's option at par beginning as of September 15, 2011, and require quarterly interest payments by the Company to the holders of the Flagstone 2006 Junior Subordinated Deferrable Debentures. Interest is payable at a floating rate of three-month LIBOR plus 354 basis points, reset quarterly. There were no redemptions made during the nine months ended September 30, 2013 and 2012.
As part of the Flagstone Acquisition, the Company assumed $113,750 of junior subordinated deferrable debentures due 2037 (the “Flagstone 2007 Junior Subordinated Deferrable Debentures”). Of these, $88,750 of the Flagstone 2007 Junior Subordinated Deferrable Debentures mature on July 30, 2037, are redeemable at the Company's option at par as of July 30, 2012, and require quarterly interest payments by the Company to the holders of the Flagstone 2007 Junior Subordinated Deferrable Debentures. Interest is payable at a floating rate of three-month LIBOR plus 300 basis points, reset quarterly. The remaining $25,000 of the Flagstone 2007 Junior Subordinated Deferrable Debentures mature on September 15, 2037, are redeemable at the Company's option at par as of September 15, 2012, and require quarterly interest payments by the Company to the holders of the Flagstone 2007 Junior Subordinated Deferrable Debentures. Interest is payable at a floating rate of three-month LIBOR plus 310 basis points, reset quarterly. There were no redemptions made during the nine months ended September 30, 2013 and 2012.
Future expected payments of principal on the 2006 and 2007 Junior Subordinated Deferrable Debentures and Flagstone 2006 and 2007 Junior Subordinated Deferrable Debentures are as follows:
2013	$	—
2014	—
2015	—
2016	—
2017 and thereafter	540,709
Total minimum future payments	$	540,709
(d)	Credit facilities
(i)	$400,000 syndicated unsecured letter of credit facility and $525,000 syndicated secured letter of credit facility
On March 9, 2012, the Company, IPCRe Limited ("IPC"), (formerly Validus Re Americas, Ltd.), PaCRe and Validus Re entered into a $400,000 four year unsecured credit facility with Deutsche Bank Securities Inc., as syndication agent, JPMorgan Chase Bank, N.A. as administrative agent, Lloyds Securities Inc. and Suntrust Bank, as co-documentation agents and the lenders party thereto, which provides for letter of credit availability for the Company and certain designated subsidiaries of the Company and revolving credit availability for the Company (the "Four Year Unsecured Facility") (the full $400,000 of which is available for letters of credit and/or revolving loans). The Four Year Unsecured Facility was provided by a syndicate of commercial banks arranged by J.P. Morgan Securities LLC, Deutsche Bank Securities Inc., Lloyds Securities Inc. and SunTrust Robinson Humphrey, Inc. Letters of credit under the Four Year Unsecured Facility are available to support obligations in connection with the insurance business of the Company and its subsidiaries. Loans under the Four Year Unsecured Facility are available for the general corporate and working capital purposes of the Company. The Company may request that existing lenders under the Four Year Unsecured Facility or prospective additional lenders agree to make available additional commitments from time to time so long as the aggregate commitments under the Four Year Unsecured Facility do not exceed $500,000. Letter of credit fees are payable on account of each letter of credit issued under the Four Year Unsecured Facility at a rate per annum equal to an applicable rate. Borrowings under the Four Year Unsecured Facility bear interest, at the option of the Company, at the base rate (the higher of the prime rate announced by JPMorgan Chase Bank, N.A., the federal funds effective rate plus 0.5%, and the adjusted LIBOR rate plus 1.0%) or the adjusted LIBOR rate applicable to such loans, plus an applicable rate.
Also on March 9, 2012, the Company, IPC and Validus Re entered into a $525,000 four-year secured credit facility with Deutsche Bank Securities Inc., as syndication agent, JPMorgan Chase Bank, N.A. as administrative agent, Lloyds Securities Inc. and Suntrust Bank, as co-documentation agents and the lenders party thereto, which provides for letter of credit availability for the Company and certain designated subsidiaries of the Company (the "Four Year Secured Facility" and together with the Four Year Unsecured Facility, the "Credit Facilities"). The Four Year Secured Facility was provided by a syndicate of commercial banks arranged by J.P. Morgan Securities LLC, Deutsche Bank Securities Inc., Lloyds Securities Inc. and SunTrust Robinson Humphrey, Inc. Letters of credit under the Four Year Secured Facility will be available to support obligations in connection with the insurance business of the Company and its subsidiaries. The Company may request that existing lenders under the Four Year Secured Facility or prospective additional lenders agree to make available additional commitments from time to time so long as the aggregate commitments under the Four Year Secured Facility do not exceed $700,000. The obligations of the Company and its designated subsidiaries under the Four Year Secured Facility are secured by cash and securities deposited into cash collateral accounts from time to time with The Bank of New York Mellon. Letter of credit fees are payable on account of each letter of credit issued under the Four Year Secured Facility at a rate per annum equal to an applicable rate. Borrowings under the Four Year Secured Facility bear interest at the base rate (the higher of the prime rate announced by JPMorgan Chase Bank, N.A., the federal funds effective rate plus 0.5%, and the adjusted LIBOR rate plus 1.0%).
The Credit Facilities contain covenants that include, among other things (i) the requirement that the Company initially maintain a minimum level of consolidated net worth of at least $2,600,000 and, commencing with the end of the fiscal quarter ending March 31, 2012, to be increased quarterly by an amount equal to 50.0% of the Company's consolidated net income (if positive) for such quarter plus 50.0% of the aggregate increases in the consolidated shareholders' equity of the Company during such fiscal quarter by reason of the issuance and sale of common equity interests of the Company, including upon any conversion of debt securities of the Company into such equity interests, (ii) the requirement that the Company maintain at all times a consolidated total debt to consolidated total capital ratio not greater than 0.35:1.00, and (iii) the requirement that Validus Re and any other material insurance subsidiaries maintain a financial strength rating by A.M. Best of not less than "B++" (Fair). In addition, the Credit Facilities contain customary negative covenants applicable to the Company and its subsidiaries, including limitations on the ability to pay dividends and other payments in respect of equity interests at any time that the Company is otherwise in default with respect to certain provisions under the respective Credit Facilities, limitations on the ability to incur liens, sell assets, merge or consolidate with others, enter into transactions with affiliates, and limitations on the ability of its subsidiaries to incur indebtedness. The Credit Facilities also contain customary affirmative covenants, representations and warranties and events of default for credit facilities of its type.
As of September 30, 2013, there was $371,990 in outstanding letters of credit under the Four Year Secured Facility (December 31, 2012: $376,570) and $nil outstanding under the Four Year Unsecured Facility (December 31, 2012: $nil).
As of September 30, 2013, and throughout the reporting periods presented, the Company was in compliance with all covenants and restrictions under the Credit Facilities.
On March 9, 2012, upon entering into the Credit Facilities, the Company terminated its (a) three-year bi-lateral $60,000 unsecured revolving credit facility, dated March 12, 2010 with Lloyds TSB Bank plc, (b) $340,000 three-year unsecured credit facility, dated March 12, 2010 with Deutsche Bank Securities Inc., as syndication agent and JPMorgan Chase Bank, N.A. as administrative agent, and (c) $500,000 five-year secured credit facility, dated March 12, 2007 with Deutsche Bank Securities Inc., as syndication agent and JPMorgan Chase Bank, N.A. as administrative agent. No early termination penalties were incurred.
(ii)	Talbot FAL Facility
On November 29, 2007, Talbot entered into a $100,000 standby Letter of Credit facility (the “Talbot FAL Facility”) to provide Funds at Lloyd’s for the 2008 and 2009 underwriting years of account; this facility is guaranteed by the Company and is secured against the assets of Validus Re. The Talbot FAL Facility was provided by a syndicate of commercial banks arranged by Lloyds TSB Bank plc and ING Bank N.V., London Branch.
On November 19, 2009, the Company entered into an Amendment and Restatement of the Talbot FAL Facility to reduce the commitment from $100,000 to $25,000, and to extend the support to the 2010 and 2011 underwriting years of account. On November 18, 2011, the Company entered into an Amendment and Restatement of the Talbot FAL Facility to extend the support to the 2012 and 2013 underwriting years of account.
As amended, the Talbot FAL Facility contains affirmative covenants that include, among other things, (i) the requirement that the Company initially maintain a minimum level of consolidated net worth of at least $2,589,615, and commencing with the end of the fiscal quarter ended December 31, 2011 to be increased quarterly by an amount equal to 50% of our consolidated net income (if positive) for such quarter plus 50% of any net proceeds received from any issuance of common shares during such quarter, and (ii) the requirement that we maintain at all times a consolidated total debt to consolidated total capitalization ratio not greater than 0.35:1.00.
The Talbot FAL Facility also contains restrictions on our ability to incur debt at our subsidiaries, incur liens, sell assets and merge or consolidate with others. Other than in respect of existing and future preferred and hybrid securities, the payment of dividends and other payments in respect of equity interests are not permitted at any time that we are in default with respect to certain provisions under the Talbot FAL Facility. As of September 30, 2013, the Company had $25,000 (December 31, 2012: $25,000) in outstanding letters of credit under this facility.
As of September 30, 2013, and throughout the reporting periods presented, the Company was in compliance with all covenants and restrictions under the Talbot FAL Facility.
(iii)	IPC Syndicated Facility and IPC bi-lateral facility
IPC obtained letters of credit through the IPC Syndicated Facility and the IPC Bi-Lateral Facility. In July 2009, certain terms of these facilities were amended including suspending IPC’s ability to increase existing letters of credit or to issue new letters of credit. Effective March 31, 2010, the IPC Syndicated Facility was closed. As of September 30, 2013, $26,019 of outstanding letters of credit were issued under the IPC bi-lateral facility (December 31, 2012: $40,613).
As of September 30, 2013, and throughout the reporting periods presented, the Company was in compliance with all covenants and restrictions under the IPC bi-lateral facility.
(iv) $200,000 secured bi-lateral letter of credit facility
On August 10, 2009, Validus Re entered into an uncommitted secured bi-lateral letter of credit facility with Citibank Europe plc (the “secured bi-lateral letter of credit facility”). Letters of credit were first issued under the Secured Bi-Lateral Letter of Credit Facility during the first quarter of 2012. As of September 30, 2013, $77,626 of letters of credit were outstanding under the Secured Bi-Lateral Letter of Credit Facility (December 31, 2012: $92,402). The secured bi-lateral letter of credit facility has no fixed termination date and as of September 30, 2013, Validus Re was in compliance with all terms and covenants thereof.
(v) $10,000 PaCRe Senior secured letter of credit facility
On May 11, 2012, PaCRe (as Borrower) and its subsidiary, PaCRe Investments, Ltd. (as Guarantor) entered into a 364-Day secured revolving credit and letter of credit facility with JPMorgan Chase Bank, N.A. This facility provides for revolving borrowings by the Borrower and for letters of credit issued by the Borrower to be used to support its reinsurance obligations in an aggregate amount of $10,000. As of September 30, 2013, $258 of letters of credit were outstanding under this facility (December 31, 2012: $219).
As of September 30, 2013, and throughout the reporting periods presented, the Company was in compliance with all covenants and restrictions under the PaCRe Senior secured letter of credit facility.
(vi) $375,000 Flagstone bi-lateral facility
As part of the Flagstone Acquisition, the Company assumed a Letter of Credit Master Agreement between Citibank Europe Plc and Flagstone Reassurance Suisse, S.A. (the “Flagstone bi-lateral facility”). At September 30, 2013, the Flagstone bi-lateral facility had $297,996 letters of credit issued and outstanding (December 31, 2012: $381,019).
As of September 30, 2013, and throughout the reporting periods presented, the Company was in compliance with all covenants and restrictions under the Flagstone bi-lateral facility.

Variable_funding_notes

Variable funding notes	9 Months Ended
	Sep. 30, 2013
Variable Funding Notes Disclosure [Abstract]	'
Variable funding notes	'
	Variable funding notes
	AlphaCat Master Fund Ltd. (“Master Fund”), a wholly-owned Bermuda registered exempt mutual fund company and AlphaCat Reinsurance Ltd. (“AlphaCat Re”), a wholly-owned Bermuda Class 3 licensed insurance company, issued Variable Funding Notes (“VFNs”) to the AlphaCat ILS funds and AlphaCat 2013.
	The purpose of the VFNs is to enable the AlphaCat ILS funds and AlphaCat 2013 to invest in specific contracts or cat bonds through the market facing entities. The economic benefit of the investments is transferred to the AlphaCat ILS funds and AlphaCat 2013 by way of interim payments, which accrue to the AlphaCat ILS funds and AlphaCat 2013 according to the earnings in AlphaCat Re and Master Fund.
	The following table presents a summary of the VFNs on the balance sheet as at September 30, 2013:
		September 30,
		2013
	AlphaCat 2013	$	214,639
	AlphaCat ILS funds	223,331
	Total	$	437,970
	For details on the VFNs interest expense which is included in the Company's Consolidated Statements of Comprehensive Income, refer to Note 12: "Debt and financing arrangements."

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Accumulated other comprehensive income (loss)	'
	Accumulated other comprehensive income (loss)
	The changes in accumulated other comprehensive income ("AOCI"), by component for the three and nine months ended September 30, 2013 are as follows:
		Three Months Ended
		30-Sep-13
		Foreign currency translation adjustments
	Beginning Balance - June 30, 2013	(8,262	)
	Amounts reclassified to retained earnings	—
	Current period foreign currency translation adjustments	4,390
	Ending balance - September 30, 2013	(3,872	)
		Nine Months Ended
		30-Sep-13
		Foreign currency translation adjustments
	Beginning Balance - December 31, 2012	(2,953	)
	Amounts reclassified to retained earnings	4,290
	Current period foreign currency translation adjustments	(5,209	)
	Ending balance - September 30, 2013	(3,872	)

Commitments_and_contingencies

Commitments and contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and contingencies	'
	Commitments and contingencies
	(a)	Concentrations of credit risk
	The Company's investments are managed following prudent standards of diversification. The Company attempts to limit its credit exposure by purchasing high quality fixed income investments to maintain an average portfolio, excluding bank loans, credit quality of AA- or higher, with mortgage and commercial mortgage-backed issues having an aggregate weighted average credit quality of AAA. In addition, the Company limits its exposure to any single issuer to 3% of its investment portfolio or less, excluding government and agency securities. With the exception of the Company's bank loan portfolio, which represents 10.9% of the Company's total investments as at September 30, 2013, the minimum credit rating of any security purchased is Baa3/BBB-. In the case where currently held investments are downgraded below Baa3/BBB-, the Company tolerates a holding of up to 2% of its investment portfolio in aggregate market value, or 10% with written authorization. Excluding bank loans, 1.3% of the portfolio had a split rating below Baa3/BBB- as at September 30, 2013. The Company did not have an aggregate exposure to any single issuer of more than 1.0% of its investment portfolio, other than with respect to government and agency securities as at September 30, 2013.
	(b)	Funds at Lloyd's
	Talbot operates in Lloyd's through a corporate member, Talbot 2002 Underwriting Capital Ltd ("T02"), which is the sole participant in Syndicate 1183. Lloyd's sets T02's required capital annually based on Syndicate 1183's business plan, rating environment and reserving environment together with input arising from Lloyd's discussions with, inter alia, regulatory and rating agencies. Such capital, called Funds at Lloyd's (“FAL”), comprises: cash, investments and undrawn letters of credit provided by various banks. The amounts of cash, investments and letters of credit at September 30, 2013 amounted to $428,700 (December 31, 2012: $428,700) of which $25,000 is provided under the Talbot FAL Facility (December 31, 2012: $25,000).
	The amounts which the Company provides as FAL are not available for distribution to the Company for the payment of dividends. Talbot’s corporate member may also be required to maintain funds under the control of Lloyd’s in excess of its capital requirement and such funds also may not be available for distribution to the Company for the payment of dividends. The amounts provided under the Talbot FAL Facility would become a liability of the Company in the event of Syndicate 1183 declaring a loss at a level between $403,700 and $428,700 which would call on this arrangement.
	(c)Lloyd's Central Fund
	Whenever a member of Lloyd's is unable to pay its debts to policyholders, such debts may be payable by the Lloyd's Central Fund. If Lloyd's determines that the Central Fund needs to be increased, it has the power to assess premium levies on current Lloyd's members up to 3% of a member's underwriting capacity in any one year. The Company does not believe that any assessment is likely in the foreseeable future and has not provided any allowance for such an assessment. However, based on the Company's 2013 underwriting capacity at Lloyd's of £620,000, at the September 30, 2013 exchange rate of £1 equals $1.6192 and assuming the maximum 3% assessment, the Company would be assessed approximately $30,117.
	(d)    Aquiline Commitment
	On December 20, 2011, Validus Re entered into an Assignment and Assumption Agreement (the "Agreement") with Aquiline Capital Partners LLC, a Delaware limited liability company (the "Assignor") and Aquiline Capital Partners II GP (Offshore) Ltd., a Cayman Islands company limited by shares (the "General Partner") pursuant to which Validus Re has assumed 100% of the Assignor's interest in Aquiline Financial Services Fund II L.P. (the "Partnership") representing a total capital commitment of $50,000 (the "Commitment"), as a limited partner in the Partnership (the "Transferred Interest"). The Transferred Interest is governed by the terms of an Amended and Restated Exempted Limited Partnership Agreement dated as of July 2, 2010 (the "Limited Partnership Agreement"). Pursuant to the terms of the Limited Partnership Agreement, the Commitment will expire on July 2, 2015. The Company's remaining commitment at September 30, 2013 was $19,292.

Related_party_transactions

Related party transactions	9 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
Related party transactions	'
	Related party transactions
	The transactions listed below are classified as related party transactions as each counter party has either a direct or indirect shareholding in the Company.
	Aquiline Capital Partners, LLC and its related companies ("Aquiline"), which own 4,946,643 shares in the Company, hold warrants to purchase 2,756,088 shares, and have two employees on the Company's Board of Directors who do not receive compensation from the Company and are shareholders of Group Ark Insurance Holdings Ltd. ("Group Ark"). Christopher E. Watson, a director of the Company, also serves as a director of Group Ark. Pursuant to reinsurance agreements with a subsidiary of Group Ark, the Company recognized gross premiums written during the three and nine months ended September 30, 2013 of $nil (2012: $6,167) and $2,848 (2012: $7,582) respectively, with $603 included in premiums receivable at September 30, 2013 (December 31, 2012: $251). The Company also recognized reinsurance premiums ceded during the three and nine months ended September 30, 2013 of $19 (2012: $nil) and $23 (2012: $nil) respectively. The Company recorded $4,420 of loss reserves recoverable at September 30, 2013 (December 31, 2012: $3,694). Earned premium adjustments of $718 (2012: $5,019) and $2,147 (2012: $5,751) were recorded during the three and nine months ended September 30, 2013 respectively.
	Aquiline was previously a shareholder of Tiger Risk Partners LLC (“Tiger Risk”). Christopher E. Watson, a director of the Company serves as a director of Tiger Risk. As of March 31, 2013, Tiger Risk was no longer a related party due to Aquiline's disposal of its investment. Pursuant to certain reinsurance contracts, the Company recognized brokerage expenses paid to Tiger Risk for the three and nine months ended September 30, 2012 of $58 and $2,418 of which $964 was included in accounts payable and accrued expenses at December 31, 2012.
	On November 24, 2009, the Company entered into an Investment Management Agreement with Conning, Inc. ("Conning") to manage a portion of the Company's investment portfolio. Aquiline acquired Conning on June 16, 2009. Jeffrey W. Greenberg, a director of the Company, serves as a director of Conning Holdings Corp., the parent company of Conning and Michael Carpenter, the Chairman of Talbot Holdings Ltd. and a director of the Company, serves as a director of a subsidiary company of Conning Holdings Corp. Investment management fees earned by Conning for the three and nine months ended September 30, 2013 were $165 (2012: $207) and $396 (2012: $611) respectively with $179 included in accounts payable and accrued expenses at September 30, 2013 (December 31, 2012: $201).
	On December 20, 2011, Validus Re entered into an Assignment and Assumption Agreement (the "Agreement") with Aquiline Capital Partners LLC, a Delaware limited liability company (the "Assignor") and Aquiline Capital Partners II GP (Offshore) Ltd., a Cayman Islands company limited by shares (the "General Partner") pursuant to which Validus Re has assumed 100% of the Assignor's interest in Aquiline Financial Services Fund II L.P. (the "Partnership") representing a total capital commitment of $50,000 (the "Commitment"), as a limited partner in the Partnership (the "Transferred Interest"). Messrs. Greenberg and Watson, directors of the Company, serve as managing principal and senior principal, respectively, of Aquiline Capital Partners LLC. For the three and nine months ended September 30, 2013, the Company incurred $505 (2012: $674) and $625 (2012: $2,560) in partnership fees and made $6,185 (2012: $430) and $13,089 (2012: $5,328) of capital contributions respectively, of which $nil was included in accounts payable and accrued expenses at September 30, 2013 (December 31, 2012: $nil).
	Certain shareholders of the Company and their affiliates, as well as the employers or entities otherwise associated with certain directors and officers or their affiliates, have purchased insurance and/or reinsurance from the Company in the ordinary course of business on terms the Company believes were no more favorable to these (re)insureds than those made available to other customers.

Earnings_per_share

Earnings per share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings per share	'
	Earnings per share
	The following table sets forth the computation of basic and diluted earnings per share for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended						Nine Months Ended
		September 30,			September 30,			September 30,			September 30,
		2013			2012			2013			2012
	Basic earnings per share
	Net income	$	229,063		$	264,044		$	419,503		$	510,540
	Loss attributable to noncontrolling interest	(45,694		)	(56,746		)	17,831			(11,386		)
	Net income available to Validus	183,369			207,298			437,334			499,154
	Less: Dividends and distributions declared on outstanding warrants	(1,552		)	(1,663		)	(17,662		)	(5,121		)
	Net income available to common shareholders	$	181,817		$	205,635		$	419,672		$	494,033
	Weighted average number of common shares outstanding	99,834,563			93,368,775			103,451,396			97,016,034
	Basic earnings per share available to common shareholders	$	1.82		$	2.2		$	4.06		$	5.09
	Diluted earnings per share
	Net income	$	229,063		$	264,044		$	419,503		$	510,540
	(Income) loss attributable to noncontrolling interest	(45,694		)	(56,746		)	17,831			(11,386		)
	Net income available to Validus	183,369			207,298			437,334			499,154
	Less: Dividends and distributions declared on outstanding warrants	—			—			(17,662		)	—
	Net income available to common shareholders	$	183,369		$	207,298		$	419,672		$	499,154
	Weighted average number of common shares outstanding	99,834,563			93,368,775			103,451,396			97,016,034
	Share equivalents:
	Warrants	2,606,669			3,248,788			—			3,116,298
	Stock options	782,158			716,693			1,090,298			777,245
	Unvested restricted shares	390,376			902,234			723,219			1,423,938
	Weighted average number of diluted common shares outstanding	103,613,766			98,236,490			105,264,913			102,333,515
	Diluted earnings per share available to common shareholders	$	1.77		$	2.11		$	3.99		$	4.88
	Share equivalents that would result in the issuance of common shares of 125,728 (2012: 2,724) and 464,516 (2012: 231,621) were outstanding for the three and nine months ended September 30, 2013, respectively, but were not included in the computation of diluted earnings per share because the effect would be antidilutive.

Segment_information

Segment information	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment information	'
	Segment information
	The Company conducts its operations worldwide through two wholly-owned subsidiaries, Validus Reinsurance, Ltd. and Talbot Holdings Ltd. from which three operating segments have been determined under U.S. GAAP segment reporting. During the first quarter of 2012, to better align the Company's operating and reporting structure with its current strategy, there was a change in the segment structure. This change included the AlphaCat group of companies as a separate operating segment. "AlphaCat segment" was included as an additional segment and includes the Company's investments in AlphaCat Re 2011, AlphaCat Re 2012, AlphaCat 2013, PaCRe and the AlphaCat ILS funds. The Company's operating segments are strategic business units that offer different products and services. They are managed and have capital allocated separately because each business requires different strategies.
	Validus Re Segment
	The Validus Re segment is focused on short-tail lines of reinsurance. The primary lines in which the segment conducts business are property, marine and specialty which includes agriculture, aerospace and aviation, financial lines of business, nuclear, terrorism, life, accident & health, workers' compensation, crisis management, contingency, motor, technical lines and composite.
	AlphaCat Segment
	The AlphaCat segment manages strategic relationships that leverage the Company's underwriting and investment expertise and earns management, performance and underwriting fees primarily from the Company's operating affiliates, AlphaCat Re 2011, AlphaCat Re 2012 and AlphaCat 2013 as well as investments in PaCRe and the AlphaCat ILS funds.
	Talbot Segment
	The Talbot segment focuses on a wide range of marine and energy, war, political violence, commercial property, financial institutions, contingency, accident & health and aviation classes of business on an insurance or facultative reinsurance basis and principally property, aerospace and marine classes of business on a treaty reinsurance basis.
	Corporate and other reconciling items
	The Company has a "Corporate" function, which includes the activities of the parent company, and which carries out certain functions for the group. "Corporate" includes non-core underwriting expenses, predominantly general and administrative and stock compensation expenses. "Corporate" also denotes the activities of certain key executives such as the Chief Executive Officer and Chief Financial Officer. For internal reporting purposes, "Corporate" is reflected separately, however "Corporate" is not considered an operating segment under these circumstances. Other reconciling items include, but are not limited to, the elimination of intersegment revenues and expenses and unusual items that are not allocated to segments.
	The following tables summarize the results of our operating segments and "Corporate":
	Three Months Ended September 30, 2013		Validus Re Segment				AlphaCat Segment				Talbot Segment				Corporate & Eliminations				Total
	Underwriting income
	Gross premiums written		$	130,925			$	3,481			$	246,468			$	(24,114	)		$	356,760
	Reinsurance premiums ceded		(13,006		)		(525		)		(49,998		)		24,114				(39,415		)
	Net premiums written		117,919				2,956				196,470				—				317,345
	Change in unearned premiums		157,873				34,210				21,860				—				213,943
	Net premiums earned		275,792				37,166				218,330				—				531,288
	Underwriting deductions
	Losses and loss expenses		62,250				15,615				100,100				—				177,965
	Policy acquisition costs		47,662				3,787				44,899				(1,448		)		94,900
	General and administrative expenses		19,785				5,728				37,402				18,174				81,089
	Share compensation expenses		2,479				152				2,992				4,904				10,527
	Total underwriting deductions		132,176				25,282				185,393				21,630				364,481
	Underwriting income (loss)		$	143,616			$	11,884			$	32,937			$	(21,630	)		$	166,807
	Net investment income		15,628				967				4,395				(981		)		20,009
	Other (loss) income		(1,892		)		3,791				73				(4,778		)		(2,806		)
	Finance expenses		(3,640		)		(11,895		)		(107		)		(11,490		)		(27,132		)
	Operating income (loss) before taxes and income from operating affiliates		153,712				4,747				37,298				(38,879		)		156,878
	Tax benefit (expense)		143				—				(513		)		365				(5		)
	Income from operating affiliates		—				1,463				—				—				1,463
	Net operating income (loss)		$	153,855			$	6,210			$	36,785			$	(38,514	)		$	158,336
	Net realized (losses) gains on investments		(10,137		)		4,084				(267		)		—				(6,320		)
	Net unrealized gains on investments		23,144				44,145				2,678				—				69,967
	Income from investment affiliate		1,044				—				—				—				1,044
	Foreign exchange gains (losses)		2,168				388				4,238				(758		)		6,036
	Net income (loss)		$	170,074			$	54,827			$	43,434			$	(39,272	)		$	229,063
	Net loss attributable to noncontrolling interest		—				(45,694		)		—				—				(45,694		)
	Net income (loss) available (attributable) to Validus		$	170,074			$	9,133			$	43,434			$	(39,272	)		$	183,369
	Selected ratios:
	Net premiums written / Gross premiums written		90.1		%		84.9		%		79.7		%						89		%
	Losses and loss expenses (a)		22.6		%		42		%		45.8		%						33.5		%
	Policy acquisition costs (a)		17.3		%		10.2		%		20.6		%						17.9		%
	General and administrative expenses (a) (b)		8.1		%		15.8		%		18.5		%						17.2		%
	Expense ratio (a)		25.4		%		26		%		39.1		%						35.1		%
	Combined ratio (a)		48		%		68		%		84.9		%						68.6		%
	Total assets		$	5,854,354			$	1,446,941			$	2,892,477			$	123,596			$	10,317,368
	(a)	Ratios are based on net premiums earned.
	(b)	The general and administrative expense ratio includes share compensation expenses.
	Three Months Ended September 30, 2012		Validus Re Segment				AlphaCat Segment				Talbot Segment				Corporate & Eliminations				Total
	Underwriting income
	Gross premiums written		$	145,010			$	2,934			$	260,755			$	(18,484	)		$	390,215
	Reinsurance premiums ceded		(10,426		)		—				(53,801		)		18,484				(45,743		)
	Net premiums written		134,584				2,934				206,954				—				344,472
	Change in unearned premiums		107,728				2,591				20,313				—				130,632
	Net premiums earned		242,312				5,525				227,267				—				475,104
	Underwriting deductions
	Losses and loss expenses		66,890				—				88,565				—				155,455
	Policy acquisition costs		37,785				547				61,640				(1,349		)		98,623
	General and administrative expenses		16,938				2,087				36,605				14,917				70,547
	Share compensation expenses		2,076				84				2,200				2,985				7,345
	Total underwriting deductions		123,689				2,718				189,010				16,553				331,970
	Underwriting income (loss)		$	118,623			$	2,807			$	38,257			$	(16,553	)		$	143,134
Net investment income		19,644				1,193				5,260				(608		)		25,489
Other income		1,543				7,674				680				(2,573		)		7,324
Finance expenses		(789		)		(56		)		(73		)		(8,444		)		(9,362		)
Operating income (loss) before taxes and income from operating affiliates		139,021				11,618				44,124				(28,178		)		166,585
Tax expense		(2		)		—				(11		)		(1,330		)		(1,343		)
Income from operating affiliates		—				6,235				—				—				6,235
Net operating income (loss)		$	139,019			$	17,853			$	44,113			$	(29,508	)		$	171,477
Net realized gains on investments		6,643				300				2,120				—				9,063
Net unrealized on investments		19,232				62,432				4,681				—				86,345
(Loss) from investment affiliate		(160		)		—				—				—				(160		)
Foreign exchange gains (losses)		8				30				1,146				(81		)		1,103
Transaction expenses (c)		—				—				—				(3,784		)		(3,784		)
Net income (loss)		$	164,742			$	80,615			$	52,060			$	(33,373	)		$	264,044
Net loss attributable to noncontrolling interest		—				(56,746		)		—				—				(56,746		)
Net income (loss) available (attributable) to Validus		$	164,742			$	23,869			$	52,060			$	(33,373	)		$	207,298
Selected ratios:
Net premiums written / Gross premiums written		92.8		%		100		%		79.4		%						88.3		%
Losses and loss expenses (a)		27.6		%		0		%		39		%						32.7		%
Policy acquisition costs (a)		15.6		%		9.9		%		27.1		%						20.8		%
General and administrative expenses (a) (b)		7.8		%		39.3		%		17.1		%						16.4		%
Expense ratio (a)		23.4		%		49.2		%		44.2		%						37.2		%
Combined ratio (a)		51		%		49.2		%		83.2		%						69.9		%
Total assets		$	4,729,344			$	768,612			$	2,931,174			$	34,690			$	8,463,820
(a)	Ratios are based on net premiums earned.
(b)	The general and administrative expense ratio includes share compensation expenses.
(c)	The transaction expenses relate to costs incurred in connection with the acquisition of Flagstone Reinsurance Holdings, S.A.
Nine Months Ended September 30, 2013		Validus Re Segment				AlphaCat Segment				Talbot Segment				Corporate & Eliminations				Total
Underwriting income
Gross premiums written		$	1,232,272			$	146,757			$	855,516			$	(70,712	)		$	2,163,833
Reinsurance premiums ceded		(226,292		)		(525		)		(191,922		)		70,712				(348,027		)
Net premiums written		1,005,980				146,232				663,594				—				1,815,806
Change in unearned premiums		(122,303		)		(46,459		)		(37,237		)		—				(205,999		)
Net premiums earned		883,677				99,773				626,357				—				1,609,807
Underwriting deductions
Losses and loss expenses		319,298				16,928				251,554				—				587,780
Policy acquisition costs		142,195				10,011				127,092				(3,635		)		275,663
General and administrative expenses		69,649				13,757				100,506				48,423				232,335
Share compensation expenses		5,421				314				6,754				6,994				19,483
Total underwriting deductions		536,563				41,010				485,906				51,782				1,115,261
Underwriting income (loss)		$	347,114			$	58,763			$	140,451			$	(51,782	)		$	494,546
Net investment income		61,770				2,821				13,496				(6,219		)		71,868
Other income (loss)		11,237				17,439				564				(24,943		)		4,297
Finance expenses		(12,133		)		(46,429		)		(256		)		(30,590		)		(89,408		)
Operating income (loss) before taxes and income from operating affiliates		407,988				32,594				154,255				(113,534		)		481,303
Tax benefit (expense)		1,755				—				(1,184		)		(351		)		220
Income from operating affiliates		—				8,779				—				—				8,779
Net operating income (loss)		$	409,743			$	41,373			$	153,071			$	(113,885	)		$	490,302
Net realized (losses) gains on investments		(5,790		)		4,084				516				—				(1,190		)
Net unrealized (losses) on investments		(36,883		)		(31,029		)		(10,706		)		—				(78,618		)
Income from investment affiliate		4,274				—				—				—				4,274
Foreign exchange gains (losses)		7,448				(663		)		(1,877		)		(173		)		4,735
Net income (loss)		$	378,792			$	13,765			$	141,004			$	(114,058	)		$	419,503
Net loss attributable to noncontrolling interest		—				17,831				—				—				17,831
Net income (loss) available (attributable) to Validus		$	378,792			$	31,596			$	141,004			$	(114,058	)		$	437,334
Selected ratios:
Net premiums written / Gross premiums written		81.6		%		99.6		%		77.6		%						83.9		%
Losses and loss expenses (a)		36.1		%		17		%		40.2		%						36.5		%
Policy acquisition costs (a)		16.1		%		10		%		20.3		%						17.2		%
General and administrative expenses (a) (b)		8.5		%		14.1		%		17.1		%						15.6		%
Expense ratio (a)		24.6		%		24.1		%		37.4		%						32.8		%
Combined ratio (a)		60.7		%		41.1		%		77.6		%						69.3		%
Total assets		$	5,854,354			$	1,446,941			$	2,892,477			$	123,596			$	10,317,368
(a)	Ratios are based on net premiums earned.
(b)	The general and administrative expense ratio includes share compensation expenses.
Nine Months Ended September 30, 2012		Validus Re Segment				AlphaCat Segment				Talbot Segment				Corporate & Eliminations				Total
Underwriting income
Gross premiums written		$	1,052,726			$	21,607			$	837,536			$	(57,276	)		$	1,854,593
Reinsurance premiums ceded		(137,504		)		—				(191,619		)		57,276				(271,847		)
Net premiums written		915,222				21,607				645,917				—				1,582,746
Change in unearned premiums		(177,215		)		(9,832		)		(21,769		)		—				(208,816		)
Net premiums earned		738,007				11,775				624,148				—				1,373,930
Underwriting deductions
Losses and loss expenses		244,286				—				296,850				—				541,136
Policy acquisition costs		113,659				1,185				142,181				(4,141		)		252,884
General and administrative expenses		48,332				5,521				100,910				43,794				198,557
Share compensation expenses		5,914				195				5,347				8,127				19,583
Total underwriting deductions		412,191				6,901				545,288				47,780				1,012,160
Underwriting income (loss)		$	325,816			$	4,874			$	78,860			$	(47,780	)		$	361,770
Net investment income		64,915				2,672				16,475				(4,928		)		79,134
Other income		4,229				22,237				2,033				(6,290		)		22,209
Finance expenses		(6,628		)		(495		)		(224		)		(32,000		)		(39,347		)
Operating income (loss) before taxes and income from operating affiliates		388,332				29,288				97,144				(90,998		)		423,766
Tax (expense) benefit		(11		)		—				(562		)		(1,313		)		(1,886		)
Income from operating affiliates		—				13,194				—				—				13,194
Net operating income (loss)		$	388,321			$	42,482			$	96,582			$	(92,311	)		$	435,074
Net realized gains on investments		17,708				216				4,825				—				22,749
Net unrealized gains on investments		35,400				12,316				5,726				—				53,442
(Loss) from investment affiliate		(558		)		—				—				—				(558		)
Foreign exchange gains (losses)		2,461				47				1,334				(225		)		3,617
Transaction expenses (c)		—				—				—				(3,784		)		(3,784		)
Net income (loss)		$	443,332			$	55,061			$	108,467			$	(96,320	)		$	510,540
Net loss attributable to noncontrolling interest		—				(11,386		)		—				—				(11,386		)
Net income (loss) available (attributable) to Validus		$	443,332			$	43,675			$	108,467			$	(96,320	)		$	499,154
Selected ratios:
Net premiums written / Gross premiums written		86.9		%		100		%		77.1		%						85.3		%
Losses and loss expenses (a)		33.1		%		0		%		47.6		%						39.4		%
Policy acquisition costs (a)		15.4		%		10.1		%		22.8		%						18.4		%
General and administrative expenses (a) (b)		7.4		%		48.5		%		17		%						15.9		%
Expense ratio (a)		22.8		%		58.6		%		39.8		%						34.3		%
Combined ratio (a)		55.9		%		58.6		%		87.4		%						73.7		%
Total assets		$	4,729,344			$	768,612			$	2,931,174			$	34,690			$	8,463,820
(a)	Ratios are based on net premiums earned.
(b)	The general and administrative expense ratio includes share compensation expenses.
(c)	The transaction expenses relate to costs incurred in connection with the acquisition of Flagstone Reinsurance Holdings, S.A.
The Company’s exposures are generally diversified across geographic zones. The following tables set forth the gross premiums written allocated to the territory of coverage exposure for the periods indicated:
	Three Months Ended September 30, 2013
	Gross Premiums Written
	Validus Re				AlphaCat				Talbot				Eliminations				Total				%
United States	$	39,618			$	2,546			$	21,573			$	(2,105	)		$	61,632			17.3	%
Worldwide excluding United States (a)	16,973				—				34,751				(4,138		)		47,586				13.3	%
Australia and New Zealand	(9,482		)		33				2,905				(236		)		(6,780		)		(1.9	)%
Europe	4,252				377				9,778				(986		)		13,421				3.8	%
Latin America and Caribbean	5,902				—				38,084				(3,353		)		40,633				11.4	%
Japan	(2,637		)		—				1,066				(117		)		(1,688		)		(0.5	)%
Canada	1,469				500				2,749				(740		)		3,978				1.1	%
Rest of the world (b)	5,641				—				22,167				(1,830		)		25,978				7.3	%
Sub-total, non United States	22,118				910				111,500				(11,400		)		123,128				34.5	%
Worldwide including United States (a)	29,611				25				18,246				(1,665		)		46,217				13	%
Other location non-specific (c)	39,578				—				95,149				(8,944		)		125,783				35.3	%
Total	$	130,925			$	3,481			$	246,468			$	(24,114	)		$	356,760			100	%
	Three Months Ended September 30, 2012
	Gross Premiums Written
	Validus Re				AlphaCat				Talbot				Eliminations				Total				%
United States	$	53,138			$	2,211			$	21,004			$	(1,482	)		$	74,871			19.2	%
Worldwide excluding United States (a)	7,085				—				28,113				(2,029		)		33,169				8.5	%
Australia and New Zealand	4,887				217				5,356				(369		)		10,091				2.6	%
Europe	10,251				512				10,426				(748		)		20,441				5.2	%
Latin America and Caribbean	3,299				—				36,735				(2,621		)		37,413				9.6	%
Japan	781				—				1,916				(136		)		2,561				0.7	%
Canada	260				—				3,696				(258		)		3,698				0.9	%
Rest of the world (b)	6,303				—				30,572				(2,133		)		34,742				8.9	%
Sub-total, non United States	32,866				729				116,814				(8,294		)		142,115				36.4	%
Worldwide including United States (a)	17,375				(6		)		17,571				(1,238		)		33,702				8.6	%
Other location non-specific (c)	41,631				—				105,366				(7,470		)		139,527				35.8	%
Total	$	145,010			$	2,934			$	260,755			$	(18,484	)		$	390,215			100	%
(a)	Represents risks in two or more geographic zones.
(b)	Represents risks in one geographic zone.
(c)	The Other location non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable such as marine and aerospace risks and can span multiple geographic areas and are not fixed locations in some instances.
	Nine Months Ended September 30, 2013
	Gross Premiums Written
	Validus Re				AlphaCat				Talbot				Eliminations				Total				%
United States	$	470,745			$	50,935			$	77,630			$	(10,599	)		$	588,711			27.2	%
Worldwide excluding United States (a)	69,482				14,801				109,562				(9,065		)		184,780				8.4	%
Australia and New Zealand	21,116				2,216				7,930				(467		)		30,795				1.4	%
Europe	64,986				2,514				41,523				(3,892		)		105,131				4.9	%
Latin America and Caribbean	5,885				—				124,120				(7,312		)		122,693				5.7	%
Japan	41,939				653				5,258				(963		)		46,887				2.2	%
Canada	4,503				818				8,790				(1,336		)		12,775				0.6	%
Rest of the world (b)	29,211				—				62,803				(3,700		)		88,314				4.1	%
Sub-total, non United States	237,122				21,002				359,986				(26,735		)		591,375				27.3	%
Worldwide including United States (a)	180,621				74,820				63,998				(10,214		)		309,225				14.3	%
Other location non-specific (c)	343,784				—				353,902				(23,164		)		674,522				31.2	%
Total	$	1,232,272			$	146,757			$	855,516			$	(70,712	)		$	2,163,833			100	%
	Nine Months Ended September 30, 2012
	Gross Premiums Written
	Validus Re				AlphaCat				Talbot				Eliminations				Total				%
United States	$	347,492			$	12,643			$	62,812			$	(4,764	)		$	418,183			22.5	%
Worldwide excluding United States (a)	51,289				278				115,836				(10,681		)		156,722				8.5	%
Australia and New Zealand	37,474				217				9,798				(721		)		46,768				2.5	%
Europe	67,206				1,332				39,871				(2,703		)		105,706				5.7	%
Latin America and Caribbean	8,456				—				112,329				(7,634		)		113,151				6.1	%
Japan	31,597				—				6,003				(407		)		37,193				2	%
Canada	2,753				—				9,366				(634		)		11,485				0.6	%
Rest of the world (b)	23,857				—				74,036				(2,133		)		95,760				5.2	%
Sub-total, non United States	222,632				1,827				367,239				(24,913		)		566,785				30.6	%
Worldwide including United States (a)	166,550				7,137				50,737				(3,440		)		220,984				11.9	%
Other location non-specific (c)	316,052				—				356,748				(24,159		)		648,641				35	%
Total	$	1,052,726			$	21,607			$	837,536			$	(57,276	)		$	1,854,593			100	%
(a)	Represents risks in two or more geographic zones.
(b)	Represents risks in one geographic zone.
(c)	The Other location non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable such as marine and aerospace risks and can span multiple geographic areas and are not fixed locations in some instances.

Subsequent_events

Subsequent events	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent events	'
	Subsequent events
	(a)	Quarterly Dividend
	On October 31, 2013, the Company announced a quarterly cash dividend of $0.30 per each common share and $0.30 per common share equivalent for which each outstanding warrant is exercisable, payable on December 31, 2013 to holders of record on December 13, 2013.
	(b)     Sale of Subsidiary
	During October, the Company completed the sale of its wholly owned subsidiary, Flagstone Alliance Insurance and Reinsurance.
	(c)    Share Repurchase Authorization
	On October 31, 2013, the Board of Directors of the Company approved an increase in the Company's common share repurchase authorization to $500,000. This amount is in addition to the $1,567,380 of common shares repurchased by the Company through October 31, 2013 under its previously authorized share repurchase programs. The Company expects the repurchases to be made from time to time in the open market or in privately negotiated transactions. The timing, form and amount of the share repurchases under the program will depend on a variety of factors, including market conditions, the Company's capital position relative to internal and rating agency targets, legal requirements and other factors. The repurchase program may be modified, extended or terminated by the Board at any time.

Significant_accounting_policie

Significant accounting policies (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Basis of preparation	'
	These unaudited consolidated financial statements include Validus Holdings, Ltd. and its subsidiaries (together, the "Company") and have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 in Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In addition, the year-end balance sheet data was derived from audited financial statements but does not include all disclosures required by U.S. GAAP. This Quarterly Report should be read in conjunction with the financial statements included in the Company's Annual Report on Form 10-K/A for the year ended December 31, 2012, as filed with the U.S. Securities and Exchange Commission (the "SEC").
	In the opinion of management, these unaudited consolidated financial statements reflect all adjustments (including normal recurring adjustments) considered necessary for a fair presentation of the Company's financial position and results of operations as at the end of and for the periods presented. Certain amounts in prior periods have been reclassified to conform to current period presentation. All intercompany accounts and transactions have been eliminated.
Use of estimates	'
	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The significant estimates reflected in the Company's consolidated financial statements include the reserve for losses and loss expenses, premium estimates for business written on a line slip or proportional basis, reinsurance premiums ceded and reinsurance recoverable balances including the provision for unrecoverable reinsurance recoverable balances and investment valuation. Actual results could differ materially from those estimates.
Reserves for losses and loss expenses	'
	Reserves for losses and loss expenses are based in part upon the estimation of case reserves reported from brokers, insureds and ceding companies. The Company also uses statistical and actuarial methods to estimate ultimate expected losses and loss expenses. The period of time from the occurrence of a loss to the reporting of a loss to the Company and to the settlement of the Company's liability may be several months or years. During this period, additional facts and trends may be revealed. As these factors become apparent, reserves will be adjusted, sometimes requiring an increase or decrease in the overall reserves of the Company, and at other times requiring a reallocation of incurred but not reported reserves to specific case reserves. These estimates are reviewed and adjusted regularly, and such adjustments, if any, are reflected in earnings in the period in which they become known. While management believes that it has made a reasonable estimate of ultimate losses, there can be no assurances that ultimate losses and loss expenses will not exceed this estimate.
Reinsurance	'
	The Company enters into reinsurance and retrocession agreements in order to mitigate its accumulation of loss, reduce its liability on individual risks, enable it to underwrite policies with higher limits and increase its aggregate capacity. The cession of insurance and reinsurance does not legally discharge the Company from its primary liability for the full amount of the policies, and the Company is required to pay the loss and bear collection risk if the reinsurer fails to meet its obligations under the reinsurance or retrocession agreement. Amounts recoverable from reinsurers are estimated in a manner consistent with the underlying liabilities.
	To estimate the provision for uncollectible reinsurance recoverable, the reinsurance recoverable is first allocated to applicable reinsurers. This determination is based on a process rather than an estimate, although an element of judgment is applied. As part of this process, ceded IBNR is allocated by reinsurer. The Company uses a default analysis to estimate uncollectible reinsurance. The primary components of the default analysis are reinsurance recoverable balances by reinsurer and default factors used to determine the portion of a reinsurer's balance deemed to be uncollectible. Default factors require considerable judgment and are determined using the current rating, or rating equivalent, of each reinsurer as well as other key considerations and assumptions.

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Investments [Abstract]	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'
	The amortized cost (or cost), gross unrealized gains and (losses) and estimated fair value of investments at September 30, 2013 were as follows:
		Amortized Cost or Cost			Gross Unrealized Gains				Gross Unrealized Losses				Estimated Fair Value
	U.S. government and government agency	$	1,319,499		$	4,313			$	(3,329	)		$	1,320,483
	Non-U.S. government and government agency	401,149			4,028				(1,180		)		403,997
	U.S. states, municipalities and political subdivisions	43,912			440				(423		)		43,929
	Agency residential mortgage-backed securities	313,177			8,384				(1,360		)		320,201
	Non-agency residential mortgage-backed securities	24,029			164				(1,062		)		23,131
	U.S. corporate	1,363,418			10,616				(6,889		)		1,367,145
	Non-U.S. corporate	686,656			5,658				(3,264		)		689,050
	Bank loans	732,922			5,421				(1,885		)		736,458
	Catastrophe bonds	56,504			2,358				—				58,862
	Asset-backed securities	474,598			1,279				(868		)		475,009
	Total fixed maturities	5,415,864			42,661				(20,260		)		5,438,265
	Total short-term investments	761,631			12				(1		)		761,642
	Other investments
	Fund of hedge funds	3,274			97				(921		)		2,450
	Private equity investments	12,493			2,259				(79		)		14,673
	Hedge funds (a)	584,519			46,087				(97,261		)		533,345
	Mutual funds	6,199			2,805				—				9,004
	Total other investments	606,485			51,248				(98,261		)		559,472
	Total	$	6,783,980		$	93,921			$	(118,522	)		$	6,759,379
	Noncontrolling interest (a)	$	(527,850	)	$	(40,887	)		$	87,535			$	(481,202	)
	Total investments excluding noncontrolling interest	$	6,256,130		$	53,034			$	(30,987	)		$	6,278,177
	(a)	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
	The amortized cost (or cost), gross unrealized gains and (losses) and estimated fair value of investments at December 31, 2012 were as follows:
		Amortized Cost or Cost			Gross Unrealized Gains				Gross Unrealized Losses				Estimated Fair Value
	U.S. government and government agency	$	1,091,357		$	7,957			$	(84	)		$	1,099,230
	Non-U.S. government and government agency	295,602			6,904				(227		)		302,279
	U.S. states, municipalities and political subdivisions	41,286			800				(23		)		42,063
	Agency residential mortgage-backed securities	375,368			13,708				(202		)		388,874
	Non-agency residential mortgage-backed securities	106,536			1,266				(1,346		)		106,456
	U.S. corporate	1,189,173			21,681				(681		)		1,210,173
	Non-U.S. corporate	582,115			11,373				(223		)		593,265
	Bank loans	663,217			10,593				(427		)		673,383
	Catastrophe bonds	56,757			481				(291		)		56,947
	Asset-backed securities	607,103			5,767				(206		)		612,664
	Total fixed maturities	5,008,514			80,530				(3,710		)		5,085,334
	Total short-term investments	1,112,929			1,349				(28		)		1,114,250
	Other investments
	Fund of hedge funds	4,677			299				(219		)		4,757
	Private equity investments	12,857			94				—				12,951
	Hedge funds (a)	559,335			21,814				(42,623		)		538,526
	Mutual funds	6,199			2,015				—				8,214
	Total other investments	583,068			24,222				(42,842		)		564,448
	Total	$	6,704,511		$	106,101			$	(46,580	)		$	6,764,032
	Noncontrolling interest (a)	(450,000		)	(19,427		)		36,690				(432,737		)
	Total investments excluding noncontrolling interest	$	6,254,511		$	86,674			$	(9,890	)		$	6,331,295
	(a)	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
Investment ratings on fixed maturities	'
		September 30, 2013						December 31, 2012
		Estimated Fair Value			% of Total			Estimated Fair Value				% of Total
	AAA	$	776,896		14.3	%		$	1,062,794			20.9	%
	AA	2,256,592			41.5	%		1,862,322				36.6	%
	A	1,196,037			22	%		1,049,969				20.6	%
	BBB	423,228			7.8	%		374,447				7.4	%
	Investment grade	4,652,753			85.6	%		4,349,532				85.5	%
	BB	356,205			6.5	%		373,907				7.4	%
	B	397,888			7.3	%		330,416				6.5	%
	CCC	4,754			0.1	%		4,483				0.1	%
	CC	2,821			0.1	%		3,259				0.1	%
	D/NR	23,844			0.4	%		23,737				0.4	%
	Non-Investment grade	785,512			14.4	%		735,802				14.5	%
	Total Fixed Maturities	$	5,438,265		100	%		$	5,085,334			100	%
Fixed maturities investments by contractual maturity	'
		September 30, 2013							December 31, 2012
		Amortized Cost			Estimated Fair Value				Amortized Cost				Estimated Fair Value
	Due in one year or less	$	745,812		$	750,992			$	526,529			$	530,499
	Due after one year through five years	3,492,605			3,504,812				2,971,118				3,018,544
	Due after five years through ten years	362,563			361,011				418,377				424,304
	Due after ten years	3,080			3,109				3,483				3,993
		4,604,060			4,619,924				3,919,507				3,977,340
	Asset-backed and mortgage-backed securities	811,804			818,341				1,089,007				1,107,994
	Total Fixed Maturities	$	5,415,864		$	5,438,265			$	5,008,514			$	5,085,334
Net investment income	'
	Net investment income was derived from the following sources:
		Three Months Ended							Nine Months Ended
		September 30,			September 30,				September 30,				September 30,
		2013			2012				2013				2012
	Fixed maturities and short-term investments	$	20,936		$	25,703			$	74,618			$	79,450
	Cash and cash equivalents	1,079			1,770				3,241				5,536
	Securities lending income	3			3				3				9
	Total gross investment income	22,018			27,476				77,862				84,995
	Investment expenses	(2,009		)	(1,987		)		(5,994		)		(5,861		)
	Net investment income	$	20,009		$	25,489			$	71,868			$	79,134
Analysis of net realized gains and change in unrealized (losses) gains on investments	'
	The following represents an analysis of net realized gains (losses) and the change in net unrealized (losses) on investments:
		Three Months Ended							Nine Months Ended
		September 30,			September 30,				September 30,				September 30,
		2013			2012				2013				2012
	Fixed maturities, short-term and other investments and cash equivalents
	Gross realized gains	$	7,706		$	10,187			$	25,578			$	29,610
	Gross realized (losses)	(14,026		)	(1,124		)		(26,768		)		(6,861		)
	Net realized (losses) gains on investments	(6,320		)	9,063				(1,190		)		22,749
	Net unrealized gains on securities lending	—			223				—				260
	Change in net unrealized gains (losses) on investments	69,967			86,122				(78,618		)		53,182
	Net change in unrealized gains (losses) on investments	$	69,967		$	86,345			$	(78,618	)		$	53,442
	Total net realized (losses) gains and change in net unrealized gains (losses) on investments	$	63,647		$	95,408			$	(79,808	)		$	76,191
	Noncontrolling interest (a)	(42,578		)	(55,806		)		25,767				(10,924		)
	Total net realized gains and change in net unrealized (losses) on investments excluding noncontrolling interest	$	21,069		$	39,602			$	(54,041	)		$	65,267
	(a)	Includes change in net unrealized (gains) losses on investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
Investments pledged as collateral under credit facilities	'
	The following tables outline investments pledged as collateral under the Company's credit facilities. For further details of the credit facilities, please refer to Note 12: “Debt and financing arrangements.”
			September 30, 2013
	Description		Commitment			Issued and Outstanding				Investments pledged as collateral
	$400,000 syndicated unsecured letter of credit facility		$	400,000		$	—			$	—
	$525,000 syndicated secured letter of credit facility		525,000			371,990				491,761
	$200,000 secured bi-lateral letter of credit facility		200,000			77,626				129,768
	Talbot FAL Facility		25,000			25,000				36,996
	PaCRe senior secured letter of credit facility		10,000			258				—
	IPC bi-lateral facility		40,000			26,019				98,260
	$375,000 Flagstone bi-lateral facility		375,000			297,996				453,241
			$	1,575,000		$	798,889			$	1,210,026
			31-Dec-12
	Description		Commitment			Issued and Outstanding				Investments pledged as collateral
	$400,000 syndicated unsecured letter of credit facility		$	400,000		$	—			$	—
	$525,000 syndicated secured letter of credit facility		525,000			376,570				517,210
	$500,000 secured bi-lateral letter of credit facility		500,000			92,402				125,991
	Talbot FAL Facility		25,000			25,000				41,372
	PaCRe senior secured letter of credit facility		10,000			219				—
	IPC bi-lateral facility		80,000			40,613				98,593
	$550,000 Flagstone bi-lateral facility		550,000			381,019				416,414
			$	2,090,000		$	915,823			$	1,199,580

Fair_value_measurements_Tables

Fair value measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair value hierarchy - allocation of investments	'
	At September 30, 2013, the Company’s investments were allocated between Levels 1, 2 and 3 as follows:
		Level 1				Level 2				Level 3			Total
	U.S. government and government agency	$	—			$	1,320,483			$	—		$	1,320,483
	Non-U.S. government and government agency	—				403,997				—			403,997
	States, municipalities, political subdivision	—				43,929				—			43,929
	Agency residential mortgage-backed securities	—				320,201				—			320,201
	Non-agency residential mortgage-backed securities	—				23,131				—			23,131
	U.S. corporate	—				1,367,145				—			1,367,145
	Non-U.S. corporate	—				689,050				—			689,050
	Bank loans	—				736,458				—			736,458
	Catastrophe bonds	—				58,862				—			58,862
	Asset-backed securities	—				475,009				—			475,009
	Total fixed maturities	—				5,438,265				—			5,438,265
	Short-term investments	755,747				5,895				—			761,642
	Other investments
	Fund of hedge funds	—				—				2,450			2,450
	Private equity investments	—				—				14,673			14,673
	Hedge funds (a)	—				—				533,345			533,345
	Mutual funds	—				9,004				—			9,004
	Total other investments	—				9,004				550,468			559,472
	Total	$	755,747			$	5,453,164			$	550,468		$	6,759,379
	Noncontrolling interest (a)	(15,730		)		—				(465,472		)	(481,202		)
	Total investments excluding noncontrolling interest	$	740,017			$	5,453,164			$	84,996		$	6,278,177
	(a)	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
	At December 31, 2012, the Company’s investments were allocated between Levels 1, 2 and 3 as follows:
		Level 1				Level 2				Level 3			Total
	U.S. government and government agency	$	—			$	1,099,230			$	—		$	1,099,230
	Non-U.S. government and government agency	—				302,279				—			302,279
	States, municipalities, political subdivision	—				42,063				—			42,063
	Agency residential mortgage-backed securities	—				388,874				—			388,874
	Non-agency residential mortgage-backed securities	—				106,456				—			106,456
	U.S. corporate	—				1,210,173				—			1,210,173
	Non-U.S. corporate	—				593,265				—			593,265
	Bank loans	—				673,383				—			673,383
	Catastrophe bonds	—				56,947				—			56,947
	Asset-backed securities	—				612,664				—			612,664
	Total fixed maturities	—				5,085,334				—			5,085,334
	Short-term investments	1,063,175				51,075				—			1,114,250
	Other investments
	Fund of hedge funds	—				—				4,757			4,757
	Private equity investments	—				—				12,951			12,951
	Hedge funds (a)	—				—				538,526			538,526
	Mutual funds	—				8,214				—			8,214
	Total other investments	—				8,214				556,234			564,448
	Total	$	1,063,175			$	5,144,623			$	556,234		$	6,764,032
	Noncontrolling interest (a)	—				—				(432,737		)	(432,737		)
	Total investments excluding noncontrolling interest	$	1,063,175			$	5,144,623			$	123,497		$	6,331,295
	(a)	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.
Reconciliation of beginning and ending balances for all Level 3 investments measured at fair value on recurring basis	'
	The following tables present a reconciliation of the beginning and ending balances for all investments measured at fair value on a recurring basis using Level 3 inputs during the three and nine months ended September 30, 2013 and 2012:
			Three Months Ended September 30, 2013				Three Months Ended September 30, 2012
			Total Fair Market Value				Total Fair Market Value
	Level 3 investments - Beginning of period		$	505,158			$	454,793
	Purchases		33,154				—
	Sales		(35,264		)		(218		)
	Net realized gains		4,503				13
	Net unrealized gains		42,917				61,746
	Transfers		—				921
	Level 3 investments - End of period		$	550,468			$	517,255
	Noncontrolling interest (a)		(465,472		)		(460,924		)
	Level 3 investments excluding noncontrolling interest		$	84,996			$	56,331
			Nine Months Ended September 30, 2013				Nine Months Ended September 30, 2012
			Total Fair Market Value				Total Fair Market Value
	Level 3 investments - Beginning of period		$	556,234			$	8,880
	Purchases		98,669				500,000
	Sales		(80,095		)		(1,115		)
	Net realized gains		4,843				61
	Net unrealized (losses) gains		(29,183		)		11,762
	Transfers		—				(2,333		)
	Level 3 investments - End of period		$	550,468			$	517,255
	Noncontrolling interest (a)		(465,472		)		(460,924		)
	Level 3 investments excluding noncontrolling interest		$	84,996			$	56,331
	(a)	Includes Level 3 investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.

Investments_in_affiliates_Tabl

Investments in affiliates (Tables)	9 Months Ended
	Sep. 30, 2013
Equity Method Investments and Joint Ventures [Abstract]	'
Reconciliation of the beginning and ending non-consolidated affiliate balance	'
	The following table presents a reconciliation of the beginning and ending investment in the Company's investment affiliate balance for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended							Nine Months Ended
		September 30,			September 30,				September 30,				September 30,
		2013			2012				2013				2012
	Investment affiliate, beginning of period	$	25,352		$	6,317			$	15,218			$	3,253
	Capital contributions	6,185			430				13,089				5,328
	Net unrealized (loss) on investments (a)	—			—				—				(1,436		)
	Income (loss) from investment affiliate	1,044			(160		)		4,274				(558		)
	Investment affiliate, end of period	$	32,581		$	6,587			$	32,581			$	6,587
	(a)	Until March 31, 2012, this investment was included in " Other investments" as a level 3 investment in the fair value hierarchy, hence the change in fair value was included in net unrealized (losses) gains on investments.
	The following table presents a reconciliation of the beginning and ending investment in operating affiliates balances for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended September 30, 2013
		Investment in operating affiliates
		AlphaCat Re 2011			AlphaCat Re 2012				AlphaCat 2013				AlphaCat ILS funds			Total
	As at June 30, 2013	$	11,054		$	5,204			$	48,536			$	20,326		$	85,120
	Return of investment	(2,800		)	(4,550		)		—				—			(7,350		)
	(Loss) income from operating affiliates	(270		)	(7		)		585				1,155			1,463
	As at September 30, 2013	$	7,984		$	647			$	49,121			$	21,481		$	79,233
		Three Months Ended September 30, 2012
		Investment in operating affiliates
		AlphaCat Re 2011			AlphaCat Re 2012				Total
	As at June 30, 2012	$	59,238		$	27,252			$	86,490
	Income from operating affiliates	4,079			2,156				6,235
	As at September 30, 2012	$	63,317		$	29,408			$	92,725
		Nine Months Ended September 30, 2013
		Investment in operating affiliates
		AlphaCat Re 2011			AlphaCat Re 2012				AlphaCat 2013				AlphaCat ILS funds			Total
	As at December 31, 2012	$	62,792		$	29,319			$	45,000			$	20,000		$	157,111
	Return of investment	(54,914		)	(31,743		)		—				—			(86,657		)
	Income from operating affiliates	106			3,071				4,121				1,481			8,779
	As at September 30, 2013	$	7,984		$	647			$	49,121			$	21,481		$	79,233
		Nine Months Ended September 30, 2012
		Investment in operating affiliates
		AlphaCat Re 2011			AlphaCat Re 2012				Total
	As at December 31, 2011	$	53,031		$	—			$	53,031
	Purchase of shares	—			26,500				26,500
	Income from operating affiliates	10,286			2,908				13,194
	As at September 30, 2012	$	63,317		$	29,408			$	92,725
Schedule of equity method investments	'
	The following table presents the Company's investments in operating affiliates as at September 30, 2013:
		Investment in operating affiliates
		Investment at cost			Voting ownership %			Equity ownership %			Carrying value
	AlphaCat Re 2011	$	8,254		43.7	%		22.3	%		$	7,984
	AlphaCat Re 2012	652			49	%		37.9	%		647
	AlphaCat 2013	45,000			40.9	%		19.7	%		49,121
	AlphaCat ILS Funds	20,000			—	%		9.1	%		21,481
	Total	$	73,906								$	79,233
	The following table presents the Company's investments in operating affiliates as at December 31, 2012:
		Investment in operating affiliates
		Investment at cost			Voting ownership %			Equity ownership %			Carrying value
	AlphaCat Re 2011	$	41,389		43.7	%		22.3	%		$	62,792
	AlphaCat Re 2012	26,500			49	%		37.9	%		29,319
	AlphaCat 2013	45,000			40.9	%		19.7	%		45,000
	AlphaCat ILS Fund	$	20,000		—	%		11.8	%		$	20,000
	Total	$	132,889								$	157,111
	The following table presents the Company's investment in the Partnership as at September 30, 2013:
		Investment in investment affiliate
		Investment at cost			Voting ownership %			Equity Ownership			Carrying Value
	Aquiline Financial Services Fund II L.P	$	30,707		—	%		6.59	%		$	32,581

Noncontrolling_interest_Tables

Noncontrolling interest (Tables)	9 Months Ended
	Sep. 30, 2013
Noncontrolling Interest [Abstract]	'
Noncontrolling interest	'
	The following table presents a reconciliation of the beginning and ending balances of noncontrolling interest for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended September 30, 2013
		PaCRe			AlphaCat ILS funds		Total
	As at June 30, 2013	$	427,755		$	70,690	$	498,445
	Purchase of shares by noncontrolling interest	—			13,000		13,000
	Net income attributable to noncontrolling interest	44,178			1,516		45,694
	As at September 30, 2013	$	471,933		$	85,206	$	557,139
		Three Months Ended September 30, 2012
		PaCRe			Total
	As at June 30, 2012	$	404,740		$	404,740
	Net income attributable to noncontrolling interest	56,746			56,746
	As at September 30, 2012	$	461,486		$	461,486
		Nine Months Ended September 30, 2013
		PaCRe			AlphaCat ILS funds		Total
	As at December 31, 2012	$	434,280		$	—	$	434,280
	Purchase of shares by noncontrolling interest	58,500			82,190		140,690
	Net (loss) income attributable to noncontrolling interest	(20,847		)	3,016		(17,831		)
	As at September 30, 2013	$	471,933		$	85,206	$	557,139
		Nine Months Ended September 30, 2012
		PaCRe			Total
	As at December 31, 2011	$	—		$	—
	Purchase of shares by noncontrolling interest	450,100			450,100
	Net income attributable to noncontrolling interest	11,386			11,386
	As at September 30, 2012	$	461,486		$	461,486

Derivative_instruments_used_in

Derivative instruments used in hedging activities (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Location and fair value amount of derivative instruments reported on the balance sheet	'
	The following table summarizes information on the location and amount of the fair value of derivatives not designated as hedging instruments on the consolidated balance sheet at September 30, 2013 and December 31, 2012:
			At September 30, 2013									At December 31, 2012
	Derivatives not designated as hedging instruments:		Net notional exposure			Asset Derivative at Fair Value (a)			Liability Derivative at Fair Value (a)			Net notional exposure			Asset Derivative at Fair Value (a)		Liability Derivative at Fair Value (a)
	Currency swaps		$	—		$	—		$	—		$	17,153		$	—	$	772
	Foreign currency forward contracts		$	—		$	—		$	—		$	310,541		$	—	$	394
	(a)	Asset and liability derivatives are classified within other assets and accounts payable and accrued expenses respectively on the Consolidated Balance Sheets.
	The following table summarizes information on the location and amount of the fair value of derivatives designated as hedging instruments on the consolidated balance sheets at September 30, 2013 and December 31, 2012:
			At September 30, 2013									At December 31, 2012
	Derivatives designated as hedging instruments:		Net notional exposure			Asset Derivative at Fair Value (a)			Liability Derivative at Fair Value (a)			Net notional exposure			Asset Derivative at Fair Value (a)		Liability Derivative at Fair Value (a)
	Foreign currency forward contracts		$	168,722		$	4,977		$	1,115		$	35,976		$	—	$	223
	Interest rate swap contracts		$	552,263		$	—		873			$	289,800		$	—	$	220
Location and amount of gains and losses related to derivative instruments reported on in the income statement	'
	The following table provides the total impact on earnings relating to the derivative instruments formally designated as fair value hedges along with the impact of the related hedged items for the three and nine months ended September 30, 2013 and 2012:
	Foreign currency forward contracts		Three Months Ended September 30, 2013			Three Months Ended September 30, 2012			Nine Months Ended September 30, 2013			Nine Months Ended September 30, 2012
	Amount of gain (loss) recognized in income on derivative		$	3,116		$	1,749		$	2,670		$	130
	Amount of gain (loss) on hedged item recognized in income attributable to risk being hedged		$	(3,116	)	$	(1,749	)	$	(2,670	)	$	(130	)
	Amount of gain (loss) recognized in income on derivative (ineffective portion)		$	—		$	—		$	—		$	—
	The gain (loss) is recognized in income within foreign exchange gains (losses).
	The following table provides the total impact on other comprehensive income and earnings relating to the derivative instruments formally designated as cash flow hedges along with the impact of the related hedged items for the three and nine months ended September 30, 2013:
	Interest rate swap contracts		Three Months Ended September 30, 2013			Three Months Ended September 30, 2012			Nine Months Ended September 30, 2013			Nine Months Ended September 30, 2012
	Amount of effective portion recognized in other comprehensive income		$	3,268		$	195		$	7,838		$	195
	Amount of effective portion subsequently reclassified to earnings		$	(3,268	)	$	(195	)	$	(7,838	)	$	(195	)
	Amount of ineffective portion excluded from effectiveness testing		$	—		$	—		$	—		$	—
	The above balances relate to interest paid and have been classified as finance expenses in the consolidated statements of comprehensive income. There was no interest rate swap contract activity for the three and nine months ended September 30, 2012

Reserve_for_losses_and_loss_ex1

Reserve for losses and loss expenses (Tables)	9 Months Ended
	Sep. 30, 2013
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]	'
Reserve for losses and loss expenses	'
	The following table represents an analysis of paid and unpaid losses and loss expenses incurred and a reconciliation of the beginning and ending unpaid losses and loss expenses for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended						Nine Months Ended
		September 30,			September 30,			September 30,			September 30,
		2013			2012			2013			2012
	Reserve for losses and loss expenses, beginning of period	$	3,283,450		$	2,591,299		$	3,517,573		$	2,631,143
	Losses and loss expenses recoverable	(418,693		)	(371,484		)	(439,967		)	(372,485		)
	Net reserves for losses and loss expenses, beginning of period	2,864,757			2,219,815			3,077,606			2,258,658
	Net reserves acquired	—			—			948			—
	Increase (decrease) in net losses and loss expenses incurred in respect of losses occurring in:
	Current year	243,015			205,219			759,617			658,884
	Prior years	(65,050		)	(49,764		)	(171,837		)	(117,748		)
	Total incurred losses and loss expenses	177,965			155,455			587,780			541,136
	Total net paid losses	(274,868		)	(144,628		)	(847,192		)	(569,380		)
	Foreign exchange	34,363			14,710			(16,925		)	14,938
	Net reserve for losses and loss expenses, end of period	2,802,217			2,245,352			2,802,217			2,245,352
	Losses and loss expenses recoverable	421,518			317,252			421,518			317,252
	Reserve for losses and loss expenses, end of period	$	3,223,735		$	2,562,604		$	3,223,735		$	2,562,604

Reinsurance_Tables

Reinsurance (Tables)	9 Months Ended
	Sep. 30, 2013
Reinsurance Disclosures [Abstract]	'
Reinsurance recoverables by reinsurer	'
	Reinsurance recoverables by reinsurer are as follows:
		September 30, 2013					December 31, 2012
		Reinsurance Recoverable			% of Total		Reinsurance Recoverable		% of Total
	Top 10 reinsurers	$	340,988		75.5	%	$	360,234	74.1	%
	Other reinsurers’ balances > $1 million	102,714			22.7	%	115,262		23.7	%
	Other reinsurers’ balances < $1 million	7,890			1.8	%	10,906		2.2	%
	Total	$	451,592		100	%	$	486,402	100	%
			September 30, 2013
	Top 10 Reinsurers		Rating	Reinsurance Recoverable			% of Total
	Lloyd's Syndicates		A+	$	74,586		21.9	%
	Everest Re		A+	52,372			15.3	%
	National Indemnity		AA+	50,984			14.9	%
	Hannover Re		AA-	45,975			13.5	%
	Fully Collateralized		NR	34,293			10.1	%
	Swiss Re		AA-	20,728			6.1	%
	Third Point Reinsurance Ltd		A-	20,049			5.9	%
	Transatlantic Re		A+	15,887			4.7	%
	XL Re		A	14,062			4.1	%
	Munich Re		AA-	12,052			3.5	%
	Total			$	340,988		100	%
			December 31, 2012
	Top 10 Reinsurers		Rating	Reinsurance Recoverable			% of Total
	Lloyd’s Syndicates		A+	$	71,469		19.9	%
	National Indemnity		AA+	59,941			16.6	%
	Everest Re		A+	51,340			14.3	%
	Fully Collateralized		NR	47,445			13.2	%
	Hannover Re		AA-	40,552			11.3	%
	Munich Re		AA-	20,954			5.8	%
	Transatlantic Re		A+	20,320			5.6	%
	Swiss Re		AA-	16,992			4.7	%
	Allianz		AA-	16,367			4.5	%
	XL Re		A	14,854			4.1	%
	Total			$	360,234		100	%
	NR: Not rated

Share_capital_Tables

Share capital (Tables)	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity Note [Abstract]	'
Summary of common shares issued and outstanding	'
	The following table is a summary of the common shares issued and outstanding:
		Common Shares
	Common shares issued, December 31, 2012	152,698,191
	Restricted share awards vested, net of shares withheld	768,889
	Restricted share units vested, net of shares withheld	14,381
	Options exercised	277,615
	Warrants exercised	591,480
	Direct issuance of common stock	928
	Performance share awards vested, net of shares withheld	31,897
	Deferred share units vested, net of shares withheld	2,935
	Common shares issued, September 30, 2013	154,386,316
	Shares repurchased, September 30, 2013	(54,488,320	)
	Common shares outstanding, September 30, 2013	99,897,996
		Common Shares
	Common shares issued, December 31, 2011	134,503,065
	Restricted share awards vested, net of shares withheld	1,545,024
	Restricted share units vested, net of shares withheld	15,173
	Options exercised	439,065
	Warrants exercised	130,121
	Common shares issued, September 30, 2012	136,632,448
	Shares repurchased, September 30, 2012	(43,138,057	)
	Common shares outstanding, September 30, 2012	93,494,391

Stock_plans_Tables

Stock plans (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Options, activity during the period	'
	Activity with respect to options for the nine months ended September 30, 2013 was as follows:
		Options		Weighted Average Grant Date Fair Value			Weighted Average Grant Date Exercise Price
	Options outstanding, December 31, 2012	1,823,947		$	6.52		$	20.69
	Options regranted (modified)	1,833,414		6.76			19.02
	Options exercised	(277,615	)	5.24			23.58
	Options cancelled (modified)	(1,733,139	)	6.76			20.12
	Options outstanding, September 30, 2013	1,646,607		$	6.75		$	18.94
	Options exercisable, September 30, 2013	1,646,607		$	6.75		$	18.94
	Activity with respect to options for the nine months ended September 30, 2012 was as follows:
		Options		Weighted Average Grant Date Fair Value			Weighted Average Grant Date Exercise Price
	Options outstanding, December 31, 2011	2,263,012		$	6.69		$	20.12
	Options exercised	(439,065	)	7.44			17.73
	Options outstanding, September 30, 2012	1,823,947		$	6.52		$	20.69
	Options exercisable, September 30, 2012	1,823,947		$	6.52		$	20.69
Restricted shares awards, activity during the period	'
	Activity with respect to unvested restricted share awards for the nine months ended September 30, 2013 was as follows:
		Restricted Share Awards		Weighted Average Grant Date Fair Value
	Restricted share awards outstanding, December 31, 2012	2,170,547		$	29.24
	Restricted share awards granted	1,580,117		36.06
	Restricted share awards vested	(930,296	)	28.08
	Restricted share awards forfeited	(110,912	)	28.34
	Restricted share awards outstanding, September 30, 2013	2,709,456		$	33.65
	Activity with respect to unvested restricted share awards for the nine months ended September 30, 2012 was as follows:
		Restricted Share Awards		Weighted Average Grant Date Fair Value
	Restricted share awards outstanding, December 31, 2011	3,003,547		$	25.77
	Restricted share awards granted	901,506		31.38
	Restricted share awards vested	(1,678,905	)	24.36
	Restricted share awards forfeited	(30,801	)	28.1
	Restricted share awards outstanding, September 30, 2012	2,195,347		$	29.12
Restricted share units, activity during the period	'
	Activity with respect to unvested restricted share units for the nine months ended September 30, 2013 was as follows:
		Restricted Share Units		Weighted Average Grant Date Fair Value
	Restricted share units outstanding, December 31, 2012	47,238		$	29.61
	Restricted share units granted	36,635		36.11
	Restricted share units vested	(21,814	)	28.17
	Restricted share units issued in lieu of cash dividends	3,924		30.29
	Restricted share units outstanding, September 30, 2013	65,983		$	33.74
	Activity with respect to unvested restricted share units for the nine months ended September 30, 2012 was as follows:
		Restricted Share Units		Weighted Average Grant Date Fair Value
	Restricted share units outstanding, December 31, 2011	53,312		$	27.6
	Restricted share units granted	16,633		31.77
	Restricted share units vested	(22,818	)	26.49
	Restricted share units issued in lieu of cash dividends	1,162		28.36
	Restricted share units forfeited	(1,393	)	28.57
	Restricted share units outstanding, September 30, 2012	46,896		$	29.61
Performance share awards, activity during the period	'
	Activity with respect to unvested performance share awards for the nine months ended September 30, 2013 was as follows:
		Performance Share Awards		Weighted Average Grant Date Fair Value
	Performance share awards outstanding, December 31, 2012	220,845		$	31.81
	Performance share awards granted	38,386		36.11
	Performance share awards vested	(39,094	)	28.7
	Performance share awards forfeited	(18,701	)	31.05
	Performance share awards conversion adjustment	(99,616	)	$	33.05
	Performance share awards outstanding, September 30, 2013	101,820		$	33.56
	Activity with respect to unvested performance share awards for the nine months ended September 30, 2012 was as follows:
		Performance Share Awards		Weighted Average Grant Date Fair Value
	Performance share awards outstanding, December 31, 2011	279,019		$	30.77
	Performance share awards granted	41,128		31.38
	Performance share awards forfeited	(99,302	)	28.7
	Performance share awards outstanding, September 30, 2012	220,845		$	31.81
Total share compensation expenses	'
	The breakdown of share compensation expenses by award type was as follows:
		Three Months Ended						Nine Months Ended
		September 30,			September 30,			September 30,			September 30,
		2013			2012			2013			2012
	Options	$	—		$	—		$	—		$	142
	Restricted share awards	10,041			6,626			20,035			18,742
	Restricted share units	168			132			419			363
	Performance share awards	318			587			(971		)	336
	Total	$	10,527		$	7,345		$	19,483		$	19,583

Debt_and_financing_arrangement1

Debt and financing arrangements (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Schedule of financing structure	'
	The financing structure at September 30, 2013 was:
		Commitment		Outstanding (a)			Drawn
	2006 Junior Subordinated Deferrable Debentures	$	150,000	$	150,000		$	150,000
	2007 Junior Subordinated Deferrable Debentures	200,000		139,800			139,800
	2010 Senior Notes due 2040	250,000		250,000			247,171
	$400,000 syndicated unsecured letter of credit facility	400,000		—			—
	$525,000 syndicated secured letter of credit facility	525,000		371,990			—
	$200,000 bi-lateral secured letter of credit facility	200,000		77,626			—
	Talbot FAL Facility (b)	25,000		25,000			—
	PaCRe senior secured letter of credit facility	10,000		258			—
	IPC bi-lateral facility	40,000		26,019			—
	$375,000 Flagstone bi-lateral facility	375,000		297,996			—
	Flagstone 2006 Junior Subordinated Deferrable Debentures	137,577		137,577			137,577
	Flagstone 2007 Junior Subordinated Deferrable Debentures	113,750		113,750			113,750
	Total	$	2,426,327	$	1,590,016		$	788,298
	The financing structure at December 31, 2012 was:
		Commitment		Outstanding (a)			Drawn
	2006 Junior Subordinated Deferrable Debentures	$	150,000	$	150,000		$	150,000
	2007 Junior Subordinated Deferrable Debentures	200,000		139,800			139,800
	2010 Senior Notes due 2040	250,000		250,000			247,090
	$400,000 syndicated unsecured letter of credit facility	400,000		—			—
	$525,000 syndicated secured letter of credit facility	525,000		376,570			—
	$500,000 secured letter of credit facility	500,000		92,402			—
	Talbot FAL Facility (b)	25,000		25,000			—
	PaCRe senior secured letter of credit facility	10,000		219			—
	IPC bi-lateral facility	80,000		40,613			—
	$550,000 Flagstone bi-lateral facility	550,000		381,019			—
	Flagstone 2006 Junior Subordinated Deferrable Debentures	137,159		137,159			137,159
	Flagstone 2007 Junior Subordinated Deferrable Debentures	113,750		113,750			113,750
	Total	$	2,940,909	$	1,706,532		$	787,799
	(a)	Indicates utilization of commitment amount, not drawn borrowings.
	(b)	Talbot operates in the Lloyd’s market ("Lloyds") through a corporate member, Talbot 2002 Underwriting Capital Ltd (“T02”), which is the sole participant in Syndicate 1183. Lloyd’s sets T02’s required capital annually based on Syndicate 1183’s business plan, rating environment, reserving environment together with input arising from Lloyd’s discussions with, inter alia, regulatory and rating agencies.  Such capital, called Funds at Lloyd’s (“FAL”), comprises: cash, investments and undrawn letters of credit provided by various banks.
Components of finance expenses	'
	Finance expenses consist of interest on our junior subordinated deferrable debentures, senior notes, variable funding notes, the amortization of debt offering costs, fees relating to our credit facilities, bank charges and the costs of FAL as follows:
		Three Months Ended					Nine Months Ended
		September 30,		September 30,			September 30,		September 30,
		2013		2012			2013		2012
	2006 Junior Subordinated Deferrable Debentures	$	2,235	$	1,628		$	6,633	$	4,729
	2007 Junior Subordinated Deferrable Debentures	1,848		1,211			5,492		7,072
	2010 Senior Notes due 2040	5,597		5,597			16,792		16,792
	Variable Funding Notes (a)	11,893		—			44,562		—
	Flagstone 2006 Junior Subordinated Deferrable Debentures	2,285		—			5,988		—
	Flagstone 2007 Junior Subordinated Deferrable Debentures	1,807		—			4,426		—
	Credit facilities	1,248		948			5,001		10,530
	Bank charges	187		(52		)	419		131
	Talbot FAL Facility	32		30			95		93
	Total	$	27,132	$	9,362		$	89,408	$	39,347
	(a)	Includes variable funding note expense and other AlphaCat related fees. Refer to Note 13: "Variable funding notes" for further details.
Future expected payments of principal	'
	Future expected payments of principal on the 2006 and 2007 Junior Subordinated Deferrable Debentures and Flagstone 2006 and 2007 Junior Subordinated Deferrable Debentures are as follows:
	2013	$	—
	2014	—
	2015	—
	2016	—
	2017 and thereafter	540,709
	Total minimum future payments	$	540,709
	Future expected payments of principal on the 2010 Senior Notes are as follows:
	2013	$	—
	2014	—
	2015	—
	2016	—
	2017 and thereafter	250,000
	Total minimum future payments	$	250,000

Variable_funding_notes_Tables

Variable funding notes (Tables)	9 Months Ended
	Sep. 30, 2013
Variable Funding Notes Disclosure [Abstract]	'
Summary of variable funding notes	'
	The following table presents a summary of the VFNs on the balance sheet as at September 30, 2013:
		September 30,
		2013
	AlphaCat 2013	$	214,639
	AlphaCat ILS funds	223,331
	Total	$	437,970

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Schedule of changes in accumulated other comprehensive income	'
	The changes in accumulated other comprehensive income ("AOCI"), by component for the three and nine months ended September 30, 2013 are as follows:
		Three Months Ended
		30-Sep-13
		Foreign currency translation adjustments
	Beginning Balance - June 30, 2013	(8,262	)
	Amounts reclassified to retained earnings	—
	Current period foreign currency translation adjustments	4,390
	Ending balance - September 30, 2013	(3,872	)
		Nine Months Ended
		30-Sep-13
		Foreign currency translation adjustments
	Beginning Balance - December 31, 2012	(2,953	)
	Amounts reclassified to retained earnings	4,290
	Current period foreign currency translation adjustments	(5,209	)
	Ending balance - September 30, 2013	(3,872	)

Earnings_per_share_Tables

Earnings per share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Computation of basic and diluted earnings per share	'
	The following table sets forth the computation of basic and diluted earnings per share for the three and nine months ended September 30, 2013 and 2012:
		Three Months Ended						Nine Months Ended
		September 30,			September 30,			September 30,			September 30,
		2013			2012			2013			2012
	Basic earnings per share
	Net income	$	229,063		$	264,044		$	419,503		$	510,540
	Loss attributable to noncontrolling interest	(45,694		)	(56,746		)	17,831			(11,386		)
	Net income available to Validus	183,369			207,298			437,334			499,154
	Less: Dividends and distributions declared on outstanding warrants	(1,552		)	(1,663		)	(17,662		)	(5,121		)
	Net income available to common shareholders	$	181,817		$	205,635		$	419,672		$	494,033
	Weighted average number of common shares outstanding	99,834,563			93,368,775			103,451,396			97,016,034
	Basic earnings per share available to common shareholders	$	1.82		$	2.2		$	4.06		$	5.09
	Diluted earnings per share
	Net income	$	229,063		$	264,044		$	419,503		$	510,540
	(Income) loss attributable to noncontrolling interest	(45,694		)	(56,746		)	17,831			(11,386		)
	Net income available to Validus	183,369			207,298			437,334			499,154
	Less: Dividends and distributions declared on outstanding warrants	—			—			(17,662		)	—
	Net income available to common shareholders	$	183,369		$	207,298		$	419,672		$	499,154
	Weighted average number of common shares outstanding	99,834,563			93,368,775			103,451,396			97,016,034
	Share equivalents:
	Warrants	2,606,669			3,248,788			—			3,116,298
	Stock options	782,158			716,693			1,090,298			777,245
	Unvested restricted shares	390,376			902,234			723,219			1,423,938
	Weighted average number of diluted common shares outstanding	103,613,766			98,236,490			105,264,913			102,333,515
	Diluted earnings per share available to common shareholders	$	1.77		$	2.11		$	3.99		$	4.88

Segment_information_Tables

Segment information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Summary of results of operating segments and corporate	'
	The following tables summarize the results of our operating segments and "Corporate":
	Three Months Ended September 30, 2013		Validus Re Segment				AlphaCat Segment				Talbot Segment				Corporate & Eliminations				Total
	Underwriting income
	Gross premiums written		$	130,925			$	3,481			$	246,468			$	(24,114	)		$	356,760
	Reinsurance premiums ceded		(13,006		)		(525		)		(49,998		)		24,114				(39,415		)
	Net premiums written		117,919				2,956				196,470				—				317,345
	Change in unearned premiums		157,873				34,210				21,860				—				213,943
	Net premiums earned		275,792				37,166				218,330				—				531,288
	Underwriting deductions
	Losses and loss expenses		62,250				15,615				100,100				—				177,965
	Policy acquisition costs		47,662				3,787				44,899				(1,448		)		94,900
	General and administrative expenses		19,785				5,728				37,402				18,174				81,089
	Share compensation expenses		2,479				152				2,992				4,904				10,527
	Total underwriting deductions		132,176				25,282				185,393				21,630				364,481
	Underwriting income (loss)		$	143,616			$	11,884			$	32,937			$	(21,630	)		$	166,807
	Net investment income		15,628				967				4,395				(981		)		20,009
	Other (loss) income		(1,892		)		3,791				73				(4,778		)		(2,806		)
	Finance expenses		(3,640		)		(11,895		)		(107		)		(11,490		)		(27,132		)
	Operating income (loss) before taxes and income from operating affiliates		153,712				4,747				37,298				(38,879		)		156,878
	Tax benefit (expense)		143				—				(513		)		365				(5		)
	Income from operating affiliates		—				1,463				—				—				1,463
	Net operating income (loss)		$	153,855			$	6,210			$	36,785			$	(38,514	)		$	158,336
	Net realized (losses) gains on investments		(10,137		)		4,084				(267		)		—				(6,320		)
	Net unrealized gains on investments		23,144				44,145				2,678				—				69,967
	Income from investment affiliate		1,044				—				—				—				1,044
	Foreign exchange gains (losses)		2,168				388				4,238				(758		)		6,036
	Net income (loss)		$	170,074			$	54,827			$	43,434			$	(39,272	)		$	229,063
	Net loss attributable to noncontrolling interest		—				(45,694		)		—				—				(45,694		)
	Net income (loss) available (attributable) to Validus		$	170,074			$	9,133			$	43,434			$	(39,272	)		$	183,369
	Selected ratios:
	Net premiums written / Gross premiums written		90.1		%		84.9		%		79.7		%						89		%
	Losses and loss expenses (a)		22.6		%		42		%		45.8		%						33.5		%
	Policy acquisition costs (a)		17.3		%		10.2		%		20.6		%						17.9		%
	General and administrative expenses (a) (b)		8.1		%		15.8		%		18.5		%						17.2		%
	Expense ratio (a)		25.4		%		26		%		39.1		%						35.1		%
	Combined ratio (a)		48		%		68		%		84.9		%						68.6		%
	Total assets		$	5,854,354			$	1,446,941			$	2,892,477			$	123,596			$	10,317,368
	(a)	Ratios are based on net premiums earned.
	(b)	The general and administrative expense ratio includes share compensation expenses.
	Three Months Ended September 30, 2012		Validus Re Segment				AlphaCat Segment				Talbot Segment				Corporate & Eliminations				Total
	Underwriting income
	Gross premiums written		$	145,010			$	2,934			$	260,755			$	(18,484	)		$	390,215
	Reinsurance premiums ceded		(10,426		)		—				(53,801		)		18,484				(45,743		)
	Net premiums written		134,584				2,934				206,954				—				344,472
	Change in unearned premiums		107,728				2,591				20,313				—				130,632
	Net premiums earned		242,312				5,525				227,267				—				475,104
	Underwriting deductions
	Losses and loss expenses		66,890				—				88,565				—				155,455
	Policy acquisition costs		37,785				547				61,640				(1,349		)		98,623
	General and administrative expenses		16,938				2,087				36,605				14,917				70,547
	Share compensation expenses		2,076				84				2,200				2,985				7,345
	Total underwriting deductions		123,689				2,718				189,010				16,553				331,970
	Underwriting income (loss)		$	118,623			$	2,807			$	38,257			$	(16,553	)		$	143,134
	Net investment income		19,644				1,193				5,260				(608		)		25,489
	Other income		1,543				7,674				680				(2,573		)		7,324
	Finance expenses		(789		)		(56		)		(73		)		(8,444		)		(9,362		)
	Operating income (loss) before taxes and income from operating affiliates		139,021				11,618				44,124				(28,178		)		166,585
	Tax expense		(2		)		—				(11		)		(1,330		)		(1,343		)
	Income from operating affiliates		—				6,235				—				—				6,235
	Net operating income (loss)		$	139,019			$	17,853			$	44,113			$	(29,508	)		$	171,477
	Net realized gains on investments		6,643				300				2,120				—				9,063
	Net unrealized on investments		19,232				62,432				4,681				—				86,345
	(Loss) from investment affiliate		(160		)		—				—				—				(160		)
Foreign exchange gains (losses)		8				30				1,146				(81		)		1,103
Transaction expenses (c)		—				—				—				(3,784		)		(3,784		)
Net income (loss)		$	164,742			$	80,615			$	52,060			$	(33,373	)		$	264,044
Net loss attributable to noncontrolling interest		—				(56,746		)		—				—				(56,746		)
Net income (loss) available (attributable) to Validus		$	164,742			$	23,869			$	52,060			$	(33,373	)		$	207,298
Selected ratios:
Net premiums written / Gross premiums written		92.8		%		100		%		79.4		%						88.3		%
Losses and loss expenses (a)		27.6		%		0		%		39		%						32.7		%
Policy acquisition costs (a)		15.6		%		9.9		%		27.1		%						20.8		%
General and administrative expenses (a) (b)		7.8		%		39.3		%		17.1		%						16.4		%
Expense ratio (a)		23.4		%		49.2		%		44.2		%						37.2		%
Combined ratio (a)		51		%		49.2		%		83.2		%						69.9		%
Total assets		$	4,729,344			$	768,612			$	2,931,174			$	34,690			$	8,463,820
(a)	Ratios are based on net premiums earned.
(b)	The general and administrative expense ratio includes share compensation expenses.
(c)	The transaction expenses relate to costs incurred in connection with the acquisition of Flagstone Reinsurance Holdings, S.A.
Nine Months Ended September 30, 2013		Validus Re Segment				AlphaCat Segment				Talbot Segment				Corporate & Eliminations				Total
Underwriting income
Gross premiums written		$	1,232,272			$	146,757			$	855,516			$	(70,712	)		$	2,163,833
Reinsurance premiums ceded		(226,292		)		(525		)		(191,922		)		70,712				(348,027		)
Net premiums written		1,005,980				146,232				663,594				—				1,815,806
Change in unearned premiums		(122,303		)		(46,459		)		(37,237		)		—				(205,999		)
Net premiums earned		883,677				99,773				626,357				—				1,609,807
Underwriting deductions
Losses and loss expenses		319,298				16,928				251,554				—				587,780
Policy acquisition costs		142,195				10,011				127,092				(3,635		)		275,663
General and administrative expenses		69,649				13,757				100,506				48,423				232,335
Share compensation expenses		5,421				314				6,754				6,994				19,483
Total underwriting deductions		536,563				41,010				485,906				51,782				1,115,261
Underwriting income (loss)		$	347,114			$	58,763			$	140,451			$	(51,782	)		$	494,546
Net investment income		61,770				2,821				13,496				(6,219		)		71,868
Other income (loss)		11,237				17,439				564				(24,943		)		4,297
Finance expenses		(12,133		)		(46,429		)		(256		)		(30,590		)		(89,408		)
Operating income (loss) before taxes and income from operating affiliates		407,988				32,594				154,255				(113,534		)		481,303
Tax benefit (expense)		1,755				—				(1,184		)		(351		)		220
Income from operating affiliates		—				8,779				—				—				8,779
Net operating income (loss)		$	409,743			$	41,373			$	153,071			$	(113,885	)		$	490,302
Net realized (losses) gains on investments		(5,790		)		4,084				516				—				(1,190		)
Net unrealized (losses) on investments		(36,883		)		(31,029		)		(10,706		)		—				(78,618		)
Income from investment affiliate		4,274				—				—				—				4,274
Foreign exchange gains (losses)		7,448				(663		)		(1,877		)		(173		)		4,735
Net income (loss)		$	378,792			$	13,765			$	141,004			$	(114,058	)		$	419,503
Net loss attributable to noncontrolling interest		—				17,831				—				—				17,831
Net income (loss) available (attributable) to Validus		$	378,792			$	31,596			$	141,004			$	(114,058	)		$	437,334
Selected ratios:
Net premiums written / Gross premiums written		81.6		%		99.6		%		77.6		%						83.9		%
Losses and loss expenses (a)		36.1		%		17		%		40.2		%						36.5		%
Policy acquisition costs (a)		16.1		%		10		%		20.3		%						17.2		%
General and administrative expenses (a) (b)		8.5		%		14.1		%		17.1		%						15.6		%
Expense ratio (a)		24.6		%		24.1		%		37.4		%						32.8		%
Combined ratio (a)		60.7		%		41.1		%		77.6		%						69.3		%
Total assets		$	5,854,354			$	1,446,941			$	2,892,477			$	123,596			$	10,317,368
(a)	Ratios are based on net premiums earned.
(b)	The general and administrative expense ratio includes share compensation expenses.
Nine Months Ended September 30, 2012		Validus Re Segment				AlphaCat Segment				Talbot Segment				Corporate & Eliminations				Total
Underwriting income
Gross premiums written		$	1,052,726			$	21,607			$	837,536			$	(57,276	)		$	1,854,593
Reinsurance premiums ceded		(137,504		)		—				(191,619		)		57,276				(271,847		)
Net premiums written		915,222				21,607				645,917				—				1,582,746
Change in unearned premiums		(177,215		)		(9,832		)		(21,769		)		—				(208,816		)
Net premiums earned		738,007				11,775				624,148				—				1,373,930
Underwriting deductions
Losses and loss expenses		244,286				—				296,850				—				541,136
Policy acquisition costs		113,659				1,185				142,181				(4,141		)		252,884
General and administrative expenses		48,332				5,521				100,910				43,794				198,557
Share compensation expenses		5,914				195				5,347				8,127				19,583
Total underwriting deductions		412,191				6,901				545,288				47,780				1,012,160
Underwriting income (loss)		$	325,816			$	4,874			$	78,860			$	(47,780	)		$	361,770
Net investment income		64,915				2,672				16,475				(4,928		)		79,134
Other income		4,229				22,237				2,033				(6,290		)		22,209
Finance expenses		(6,628		)		(495		)		(224		)		(32,000		)		(39,347		)
Operating income (loss) before taxes and income from operating affiliates		388,332				29,288				97,144				(90,998		)		423,766
Tax (expense) benefit		(11		)		—				(562		)		(1,313		)		(1,886		)
Income from operating affiliates		—				13,194				—				—				13,194
Net operating income (loss)		$	388,321			$	42,482			$	96,582			$	(92,311	)		$	435,074
Net realized gains on investments		17,708				216				4,825				—				22,749
Net unrealized gains on investments		35,400				12,316				5,726				—				53,442
(Loss) from investment affiliate		(558		)		—				—				—				(558		)
Foreign exchange gains (losses)		2,461				47				1,334				(225		)		3,617
Transaction expenses (c)		—				—				—				(3,784		)		(3,784		)
Net income (loss)		$	443,332			$	55,061			$	108,467			$	(96,320	)		$	510,540
Net loss attributable to noncontrolling interest		—				(11,386		)		—				—				(11,386		)
Net income (loss) available (attributable) to Validus		$	443,332			$	43,675			$	108,467			$	(96,320	)		$	499,154
Selected ratios:
Net premiums written / Gross premiums written		86.9		%		100		%		77.1		%						85.3		%
Losses and loss expenses (a)		33.1		%		0		%		47.6		%						39.4		%
Policy acquisition costs (a)		15.4		%		10.1		%		22.8		%						18.4		%
General and administrative expenses (a) (b)		7.4		%		48.5		%		17		%						15.9		%
Expense ratio (a)		22.8		%		58.6		%		39.8		%						34.3		%
Combined ratio (a)		55.9		%		58.6		%		87.4		%						73.7		%
Total assets		$	4,729,344			$	768,612			$	2,931,174			$	34,690			$	8,463,820
(a)	Ratios are based on net premiums earned.
(b)	The general and administrative expense ratio includes share compensation expenses.
(c)	The transaction expenses relate to costs incurred in connection with the acquisition of Flagstone Reinsurance Holdings, S.A.
Gross premiums written allocated to the territory of coverage exposure	'
	The following tables set forth the gross premiums written allocated to the territory of coverage exposure for the periods indicated:
		Three Months Ended September 30, 2013
		Gross Premiums Written
		Validus Re				AlphaCat				Talbot				Eliminations				Total				%
	United States	$	39,618			$	2,546			$	21,573			$	(2,105	)		$	61,632			17.3	%
	Worldwide excluding United States (a)	16,973				—				34,751				(4,138		)		47,586				13.3	%
	Australia and New Zealand	(9,482		)		33				2,905				(236		)		(6,780		)		(1.9	)%
	Europe	4,252				377				9,778				(986		)		13,421				3.8	%
	Latin America and Caribbean	5,902				—				38,084				(3,353		)		40,633				11.4	%
	Japan	(2,637		)		—				1,066				(117		)		(1,688		)		(0.5	)%
	Canada	1,469				500				2,749				(740		)		3,978				1.1	%
	Rest of the world (b)	5,641				—				22,167				(1,830		)		25,978				7.3	%
	Sub-total, non United States	22,118				910				111,500				(11,400		)		123,128				34.5	%
	Worldwide including United States (a)	29,611				25				18,246				(1,665		)		46,217				13	%
	Other location non-specific (c)	39,578				—				95,149				(8,944		)		125,783				35.3	%
	Total	$	130,925			$	3,481			$	246,468			$	(24,114	)		$	356,760			100	%
		Three Months Ended September 30, 2012
		Gross Premiums Written
		Validus Re				AlphaCat				Talbot				Eliminations				Total				%
	United States	$	53,138			$	2,211			$	21,004			$	(1,482	)		$	74,871			19.2	%
	Worldwide excluding United States (a)	7,085				—				28,113				(2,029		)		33,169				8.5	%
	Australia and New Zealand	4,887				217				5,356				(369		)		10,091				2.6	%
	Europe	10,251				512				10,426				(748		)		20,441				5.2	%
	Latin America and Caribbean	3,299				—				36,735				(2,621		)		37,413				9.6	%
	Japan	781				—				1,916				(136		)		2,561				0.7	%
	Canada	260				—				3,696				(258		)		3,698				0.9	%
	Rest of the world (b)	6,303				—				30,572				(2,133		)		34,742				8.9	%
	Sub-total, non United States	32,866				729				116,814				(8,294		)		142,115				36.4	%
	Worldwide including United States (a)	17,375				(6		)		17,571				(1,238		)		33,702				8.6	%
	Other location non-specific (c)	41,631				—				105,366				(7,470		)		139,527				35.8	%
	Total	$	145,010			$	2,934			$	260,755			$	(18,484	)		$	390,215			100	%
	(a)	Represents risks in two or more geographic zones.
	(b)	Represents risks in one geographic zone.
	(c)	The Other location non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable such as marine and aerospace risks and can span multiple geographic areas and are not fixed locations in some instances.
		Nine Months Ended September 30, 2013
		Gross Premiums Written
		Validus Re				AlphaCat				Talbot				Eliminations				Total				%
	United States	$	470,745			$	50,935			$	77,630			$	(10,599	)		$	588,711			27.2	%
	Worldwide excluding United States (a)	69,482				14,801				109,562				(9,065		)		184,780				8.4	%
	Australia and New Zealand	21,116				2,216				7,930				(467		)		30,795				1.4	%
	Europe	64,986				2,514				41,523				(3,892		)		105,131				4.9	%
	Latin America and Caribbean	5,885				—				124,120				(7,312		)		122,693				5.7	%
	Japan	41,939				653				5,258				(963		)		46,887				2.2	%
	Canada	4,503				818				8,790				(1,336		)		12,775				0.6	%
	Rest of the world (b)	29,211				—				62,803				(3,700		)		88,314				4.1	%
	Sub-total, non United States	237,122				21,002				359,986				(26,735		)		591,375				27.3	%
	Worldwide including United States (a)	180,621				74,820				63,998				(10,214		)		309,225				14.3	%
	Other location non-specific (c)	343,784				—				353,902				(23,164		)		674,522				31.2	%
	Total	$	1,232,272			$	146,757			$	855,516			$	(70,712	)		$	2,163,833			100	%
		Nine Months Ended September 30, 2012
		Gross Premiums Written
		Validus Re				AlphaCat				Talbot				Eliminations				Total				%
	United States	$	347,492			$	12,643			$	62,812			$	(4,764	)		$	418,183			22.5	%
	Worldwide excluding United States (a)	51,289				278				115,836				(10,681		)		156,722				8.5	%
	Australia and New Zealand	37,474				217				9,798				(721		)		46,768				2.5	%
	Europe	67,206				1,332				39,871				(2,703		)		105,706				5.7	%
	Latin America and Caribbean	8,456				—				112,329				(7,634		)		113,151				6.1	%
	Japan	31,597				—				6,003				(407		)		37,193				2	%
	Canada	2,753				—				9,366				(634		)		11,485				0.6	%
	Rest of the world (b)	23,857				—				74,036				(2,133		)		95,760				5.2	%
	Sub-total, non United States	222,632				1,827				367,239				(24,913		)		566,785				30.6	%
	Worldwide including United States (a)	166,550				7,137				50,737				(3,440		)		220,984				11.9	%
	Other location non-specific (c)	316,052				—				356,748				(24,159		)		648,641				35	%
Total	$	1,052,726			$	21,607			$	837,536			$	(57,276	)		$	1,854,593			100	%
(a)	Represents risks in two or more geographic zones.
(b)	Represents risks in one geographic zone.
(c)	The Other location non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable such as marine and aerospace risks and can span multiple geographic areas and are not fixed locations in some instances.

Basis_of_preparation_and_conso1

Basis of preparation and consolidation Basis of preparation and consolidation (Details) (Flagstone Reinsurance Holdings Sa [Member], USD $)	0 Months Ended
	Nov. 30, 2012
Flagstone Reinsurance Holdings Sa [Member]	'
Business Acquisition [Line Items]	'
Exchange ratio (in shares)	0.1935
Per share price paid by Company to acquire FSR common shares	$2

Investments_Gross_unrealized_g

Investments (Gross unrealized gains and losses on fixed maturities) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	$5,415,864	$5,008,514
Short-term investments, at amortized cost	761,631	1,112,929
Other investments, at cost	606,485	583,068
Amortized cost	6,783,980	6,704,511
Noncontrolling interest, cost or amortized cost	-527,850	-450,000	[1]
Total investments excluding non-controlling interest, cost or amortized cost	6,256,130	6,254,511
Fixed maturities, gross unrealized gains	42,661	80,530
Short term investments, gross unrealized gains	12	1,349
Other investments, gross unrealized gains	51,248	24,222
Gross unrealized gains	93,921	106,101
Noncontrolling interest share of unrealized gains other investments	-40,887	-19,427	[1]
Total investments excluding non-controlling interest, unrealized gains	53,034	86,674
Fixed maturities, gross unrealized losses	-20,260	-3,710
Short term investments, gross unrealized losses	-1	-28
Other investments, gross unrealized losses	-98,261	-42,842
Gross unrealized losses	-118,522	-46,580
Noncontrolling interest share of unrealized losses	87,535	36,690	[1]
Total investments excluding non-controlling interest, unrealized losses	-30,987	-9,890
Total fixed maturities	5,438,265	5,085,334
Short-term investments	761,642	1,114,250
Other investments	559,472	564,448
Total	6,759,379	6,764,032
Noncontrolling interest	-481,202	-432,737	[1]
Total investments excluding noncontrolling interest	6,278,177	6,331,295
U.S. government and government agency	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	1,319,499	1,091,357
Fixed maturities, gross unrealized gains	4,313	7,957
Fixed maturities, gross unrealized losses	-3,329	-84
Total fixed maturities	1,320,483	1,099,230
Non-U.S. government and government agency	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	401,149	295,602
Fixed maturities, gross unrealized gains	4,028	6,904
Fixed maturities, gross unrealized losses	-1,180	-227
Total fixed maturities	403,997	302,279
U.S. states, municipalities and political subdivisions	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	43,912	41,286
Fixed maturities, gross unrealized gains	440	800
Fixed maturities, gross unrealized losses	-423	-23
Total fixed maturities	43,929	42,063
Agency residential mortgage-backed securities	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	313,177	375,368
Fixed maturities, gross unrealized gains	8,384	13,708
Fixed maturities, gross unrealized losses	-1,360	-202
Total fixed maturities	320,201	388,874
Non-agency residential mortgage-backed securities	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	24,029	106,536
Fixed maturities, gross unrealized gains	164	1,266
Fixed maturities, gross unrealized losses	-1,062	-1,346
Total fixed maturities	23,131	106,456
U.S. corporate	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	1,363,418	1,189,173
Fixed maturities, gross unrealized gains	10,616	21,681
Fixed maturities, gross unrealized losses	-6,889	-681
Total fixed maturities	1,367,145	1,210,173
Non-U.S. corporate	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	686,656	582,115
Fixed maturities, gross unrealized gains	5,658	11,373
Fixed maturities, gross unrealized losses	-3,264	-223
Total fixed maturities	689,050	593,265
Bank loans	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	732,922	663,217
Fixed maturities, gross unrealized gains	5,421	10,593
Fixed maturities, gross unrealized losses	-1,885	-427
Total fixed maturities	736,458	673,383
Catastrophe bonds	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	56,504	56,757
Fixed maturities, gross unrealized gains	2,358	481
Fixed maturities, gross unrealized losses	0	-291
Total fixed maturities	58,862	56,947
Asset-backed securities	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Fixed maturities, at amortized cost	474,598	607,103
Fixed maturities, gross unrealized gains	1,279	5,767
Fixed maturities, gross unrealized losses	-868	-206
Total fixed maturities	475,009	612,664
Fund of hedge funds	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Other investments, at cost	3,274	4,677
Other investments, gross unrealized gains	97	299
Other investments, gross unrealized losses	-921	-219
Other investments	2,450	4,757
Private equity investments	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Other investments, at cost	12,493	12,857
Other investments, gross unrealized gains	2,259	94
Other investments, gross unrealized losses	-79	0
Other investments	14,673	12,951
Hedge funds	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Other investments, at cost	584,519	559,335	[1]
Other investments, gross unrealized gains	46,087	21,814	[1]
Other investments, gross unrealized losses	-97,261	-42,623	[1]
Other investments	533,345	538,526	[1]
Mutual funds	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Other investments, at cost	6,199	6,199
Other investments, gross unrealized gains	2,805	2,015
Other investments, gross unrealized losses	0	0
Other investments	$9,004	$8,214
PaCRe funds	'	'
Amortized cost, gross unrealized gains and (losses) and estimated fair value of investments	'	'
Noncontrolling Interest, Ownership Percentage by Parent	10.00%	10.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	90.00%	90.00%
[1]	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.

Investments_Fixed_maturities_b

Investments (Fixed maturities by investment rating) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fixed Maturities	'	'
Estimated fair value	$5,438,265	$5,085,334
Percentage of total	100.00%	100.00%
Investment Grade	'	'
Fixed Maturities	'	'
Estimated fair value	4,652,753	4,349,532
Percentage of total	85.60%	85.50%
AAA	'	'
Fixed Maturities	'	'
Estimated fair value	776,896	1,062,794
Percentage of total	14.30%	20.90%
AA	'	'
Fixed Maturities	'	'
Estimated fair value	2,256,592	1,862,322
Percentage of total	41.50%	36.60%
A	'	'
Fixed Maturities	'	'
Estimated fair value	1,196,037	1,049,969
Percentage of total	22.00%	20.60%
BBB	'	'
Fixed Maturities	'	'
Estimated fair value	423,228	374,447
Percentage of total	7.80%	7.40%
Non Investment Grade	'	'
Fixed Maturities	'	'
Estimated fair value	785,512	735,802
Percentage of total	14.40%	14.50%
BB	'	'
Fixed Maturities	'	'
Estimated fair value	356,205	373,907
Percentage of total	6.50%	7.40%
B	'	'
Fixed Maturities	'	'
Estimated fair value	397,888	330,416
Percentage of total	7.30%	6.50%
CCC	'	'
Fixed Maturities	'	'
Estimated fair value	4,754	4,483
Percentage of total	0.10%	0.10%
CC	'	'
Fixed Maturities	'	'
Estimated fair value	2,821	3,259
Percentage of total	0.10%	0.10%
D/NR	'	'
Fixed Maturities	'	'
Estimated fair value	$23,844	$23,737
Percentage of total	0.40%	0.40%

Investments_Maturity_profile_o

Investments (Maturity profile of fixed maturity investments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Maturity profile	'	'
Amortized cost	$5,415,864	$5,008,514
Estimated fair value	5,438,265	5,085,334
Fixed maturities trading securities allocated to contractual maturity	'	'
Maturity profile	'	'
Amortized cost	4,604,060	3,919,507
Estimated fair value	4,619,924	3,977,340
Due in one year or less | Fixed maturities trading securities allocated to contractual maturity	'	'
Maturity profile	'	'
Amortized cost	745,812	526,529
Estimated fair value	750,992	530,499
Due after one year through five years | Fixed maturities trading securities allocated to contractual maturity	'	'
Maturity profile	'	'
Amortized cost	3,492,605	2,971,118
Estimated fair value	3,504,812	3,018,544
Due after five years through ten years | Fixed maturities trading securities allocated to contractual maturity	'	'
Maturity profile	'	'
Amortized cost	362,563	418,377
Estimated fair value	361,011	424,304
Due after ten years | Fixed maturities trading securities allocated to contractual maturity	'	'
Maturity profile	'	'
Amortized cost	3,080	3,483
Estimated fair value	3,109	3,993
Asset backed and mortgaged backed securities | No single maturity date	'	'
Maturity profile	'	'
Amortized cost	811,804	1,089,007
Estimated fair value	$818,341	$1,107,994

Investments_Components_of_net_

Investments (Components of net investment income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net investment income	'	'	'	'
Total gross investment income	$22,018	$27,476	$77,862	$84,995
Investment expenses	-2,009	-1,987	-5,994	-5,861
Net investment income	20,009	25,489	71,868	79,134
Fixed maturities and short term investments	'	'	'	'
Net investment income	'	'	'	'
Total gross investment income	20,936	25,703	74,618	79,450
Cash and cash equivalents	'	'	'	'
Net investment income	'	'	'	'
Total gross investment income	1,079	1,770	3,241	5,536
Securities lending income	'	'	'	'
Net investment income	'	'	'	'
Total gross investment income	$3	$3	$3	$9

Investments_Realized_and_unrea

Investments (Realized and unrealized gains) (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

PaCRe funds

PaCRe funds

Securities lending

Securities lending

Securities lending

Securities lending

Investments excluding securities lending

Investments excluding securities lending

Investments excluding securities lending

Investments excluding securities lending

Schedule of Trading Securities and Other Trading Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Noncontrolling Interest, Ownership Percentage by Parent

'

'

'

'

10.00%

10.00%

'

'

'

'

'

'

'

'

Fixed maturities, short-term and other investments and cash equivalents

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gross realized gains

$7,706

$10,187

$25,578

$29,610

'

'

'

'

'

'

'

'

'

'

Gross realized (losses)

-14,026

-1,124

-26,768

-6,861

'

'

'

'

'

'

'

'

'

'

Net realized gains on investments

-6,320

9,063

-1,190

22,749

'

'

'

'

'

'

'

'

'

'

Change in net unrealized gains (losses) on investments

69,967

86,345

-78,618

53,442

'

'

0

223

0

260

69,967

86,122

-78,618

53,182

Total net realized gains and change in net unrealized gains (losses) on investments

63,647

95,408

-79,808

76,191

'

'

'

'

'

'

'

'

'

'

Noncontrolling interest

-42,578

[1]

-55,806

[1]

25,767

[1]

-10,924

[1]

'

'

'

'

'

'

'

'

'

'

Total net realized gains and change in net unrealized gains (losses) on investments excluding noncontrolling interest

$21,069

$39,602

($54,041)

$65,267

'

'

'

'

'

'

'

'

'

'

Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners

'

'

'

'

90.00%

90.00%

'

'

'

'

'

'

'

'

[1]

Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.

Investments_Investments_pledge

Investments (Investments pledged as collateral) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Financial Instruments Owned and Pledged as Collateral [Line Items]	'		'
Credit facility, commitment	$1,575,000		$2,090,000
Letters of credit issued and outstanding	798,889		915,823
Investments pledged as collateral	1,210,026		1,199,580
$400,000 syndicated unsecured letter of credit facility	'		'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'		'
Credit facility, commitment	400,000		400,000
Letters of credit issued and outstanding	0		0
Investments pledged as collateral	0		0
$525,000 syndicated secured letter of credit facility	'		'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'		'
Credit facility, commitment	525,000		525,000
Letters of credit issued and outstanding	371,990		376,570
Investments pledged as collateral	491,761		517,210
Bi-lateral secured facility	'		'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'		'
Credit facility, commitment	200,000		500,000
Letters of credit issued and outstanding	77,626		92,402
Investments pledged as collateral	129,768		125,991
Talbot FAL Facility	'		'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'		'
Credit facility, commitment	25,000	[1]	25,000	[1]
Letters of credit issued and outstanding	25,000		25,000
Investments pledged as collateral	36,996		41,372
PaCRe Senior secured letter of credit facility	'		'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'		'
Credit facility, commitment	10,000		10,000
Letters of credit issued and outstanding	258		219
Investments pledged as collateral	0		0
IPC Bi Lateral Facility	'		'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'		'
Credit facility, commitment	40,000	[2]	80,000	[2]
Letters of credit issued and outstanding	26,019		40,613
Investments pledged as collateral	98,260		98,593
Flagstone BiLateral Facility	'		'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'		'
Credit facility, commitment	375,000		550,000
Letters of credit issued and outstanding	297,996		381,019
Investments pledged as collateral	$453,241		$416,414
[1]	Talbot operates in the Lloyd’s market ("Lloyds") through a corporate member, Talbot 2002 Underwriting Capital Ltd (“T02”), which is the sole participant in Syndicate 1183. Lloyd’s sets T02’s required capital annually based on Syndicate 1183’s business plan, rating environment, reserving environment together with input arising from Lloyd’s discussions with, inter alia, regulatory and rating agencies. Such capital, called Funds at Lloyd’s (“FAL”), comprises: cash, investments and undrawn letters of credit provided by various banks.
[2]	Indicates utilization of commitment amount, not drawn borrowings.

Fair_value_measurements_Fair_v

Fair value measurements (Fair value hierarchy) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	$5,438,265		$5,085,334
Short-term investments, at fair value	761,642		1,114,250
Other investments, at fair value	559,472		564,448
Total	6,759,379		6,764,032
Noncontrolling interest	-481,202		-432,737	[1]
Total investments excluding noncontrolling interest	6,278,177		6,331,295
U.S. government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	1,320,483		1,099,230
Non-US government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	403,997		302,279
States, municipalities, political subdivision	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	43,929		42,063
Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	320,201		388,874
Non-Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	23,131		106,456
U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	1,367,145		1,210,173
Non-U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	689,050		593,265
Bank loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	736,458		673,383
Catastrophe bonds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	58,862		56,947
Asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	475,009		612,664
Fund of hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	2,450		4,757
Private equity investments	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	14,673		12,951
Hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	533,345		538,526	[1]
Mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	9,004		8,214
PaCRe funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Noncontrolling Interest, Ownership Percentage by Parent	10.00%		10.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	90.00%		90.00%
Fair Value, Measurements, Recurring [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	5,438,265		5,085,334
Short-term investments, at fair value	761,642		1,114,250
Other investments, at fair value	559,472		564,448
Total	6,759,379		6,764,032
Noncontrolling interest	-481,202	[1]	-432,737	[1]
Total investments excluding noncontrolling interest	6,278,177		6,331,295
Fair Value, Measurements, Recurring [Member] | U.S. government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	1,320,483		1,099,230
Fair Value, Measurements, Recurring [Member] | Non-US government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	403,997		302,279
Fair Value, Measurements, Recurring [Member] | States, municipalities, political subdivision	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	43,929		42,063
Fair Value, Measurements, Recurring [Member] | Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	320,201		388,874
Fair Value, Measurements, Recurring [Member] | Non-Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	23,131		106,456
Fair Value, Measurements, Recurring [Member] | U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	1,367,145		1,210,173
Fair Value, Measurements, Recurring [Member] | Non-U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	689,050		593,265
Fair Value, Measurements, Recurring [Member] | Bank loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	736,458		673,383
Fair Value, Measurements, Recurring [Member] | Catastrophe bonds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	58,862		56,947
Fair Value, Measurements, Recurring [Member] | Asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	475,009		612,664
Fair Value, Measurements, Recurring [Member] | Fund of hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	2,450		4,757
Fair Value, Measurements, Recurring [Member] | Private equity investments	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	14,673		12,951
Fair Value, Measurements, Recurring [Member] | Hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	533,345	[1]	538,526	[1]
Fair Value, Measurements, Recurring [Member] | Mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	9,004		8,214
Fair Value, Measurements, Recurring [Member] | Level 1	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Short-term investments, at fair value	755,747		1,063,175
Other investments, at fair value	0		0
Total	755,747		1,063,175
Noncontrolling interest	-15,730	[1]	0	[1]
Total investments excluding noncontrolling interest	740,017		1,063,175
Fair Value, Measurements, Recurring [Member] | Level 1 | U.S. government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Non-US government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | States, municipalities, political subdivision	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Non-Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Non-U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Bank loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Catastrophe bonds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Fund of hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Private equity investments	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 1 | Hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	0	[1]	0	[1]
Fair Value, Measurements, Recurring [Member] | Level 1 | Mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 2	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	5,438,265		5,085,334
Short-term investments, at fair value	5,895		51,075
Other investments, at fair value	9,004		8,214
Total	5,453,164		5,144,623
Noncontrolling interest	0	[1]	0	[1]
Total investments excluding noncontrolling interest	5,453,164		5,144,623
Fair Value, Measurements, Recurring [Member] | Level 2 | U.S. government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	1,320,483		1,099,230
Fair Value, Measurements, Recurring [Member] | Level 2 | Non-US government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	403,997		302,279
Fair Value, Measurements, Recurring [Member] | Level 2 | States, municipalities, political subdivision	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	43,929		42,063
Fair Value, Measurements, Recurring [Member] | Level 2 | Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	320,201		388,874
Fair Value, Measurements, Recurring [Member] | Level 2 | Non-Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	23,131		106,456
Fair Value, Measurements, Recurring [Member] | Level 2 | U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	1,367,145		1,210,173
Fair Value, Measurements, Recurring [Member] | Level 2 | Non-U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	689,050		593,265
Fair Value, Measurements, Recurring [Member] | Level 2 | Bank loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	736,458		673,383
Fair Value, Measurements, Recurring [Member] | Level 2 | Catastrophe bonds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	58,862		56,947
Fair Value, Measurements, Recurring [Member] | Level 2 | Asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	475,009		612,664
Fair Value, Measurements, Recurring [Member] | Level 2 | Fund of hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 2 | Private equity investments	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 2 | Hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	0	[1]	0	[1]
Fair Value, Measurements, Recurring [Member] | Level 2 | Mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	9,004		8,214
Fair Value, Measurements, Recurring [Member] | Level 3	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Short-term investments, at fair value	0		0
Other investments, at fair value	550,468		556,234
Total	550,468		556,234
Noncontrolling interest	-465,472	[1]	-432,737	[1]
Total investments excluding noncontrolling interest	84,996		123,497
Percentage Of Fair Value Assets Measured On Recurring Basis	1.40%		2.00%
Fair Value, Measurements, Recurring [Member] | Level 3 | U.S. government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | Non-US government and government agency	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | States, municipalities, political subdivision	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | Non-Agency residential mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | Non-U.S. corporate	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | Bank loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | Catastrophe bonds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | Asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Fixed maturities, at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Level 3 | Fund of hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	2,450		4,757
Fair Value, Measurements, Recurring [Member] | Level 3 | Private equity investments	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	14,673		12,951
Fair Value, Measurements, Recurring [Member] | Level 3 | Hedge funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	533,345	[1]	538,526	[1]
Fair Value, Measurements, Recurring [Member] | Level 3 | Mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Other investments, at fair value	$0		$0
[1]	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.

Fair_value_measurements_Level_

Fair value measurements (Level 3 rollforward) (Details) (USD $)

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

In Thousands, unless otherwise specified

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

PaCRe funds

PaCRe funds

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Other Investments

Other Investments

Other Investments

Other Investments

Reconciliation of beginning and ending balances for all investments measured at fair value on recurring basis

'

'

'

'

'

'

'

'

'

'

'

'

Noncontrolling Interest, Ownership Percentage by Parent

'

'

'

'

'

'

'

'

'

'

10.00%

10.00%

Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners

'

'

'

'

'

'

'

'

'

'

90.00%

90.00%

Level 3 investments - beginning of period

'

'

'

'

'

'

$505,158

$454,793

$556,234

$8,880

'

'

Purchases

'

'

'

'

'

'

33,154

0

98,669

500,000

'

'

Sales

'

'

'

'

'

'

-35,264

-218

-80,095

-1,115

'

'

Realized gains

'

'

'

'

'

'

4,503

13

4,843

61

'

'

Unrealized losses

'

'

'

'

'

'

42,917

61,746

-29,183

11,762

'

'

Transfers

'

'

'

'

'

'

0

921

0

-2,333

'

'

Level 3 investments - end of period

'

'

'

'

'

'

550,468

517,255

550,468

517,255

'

'

Noncontrolling interest

-481,202

-432,737

[1]

-481,202

[1]

-432,737

[1]

-465,472

[1]

-432,737

[1]

-465,472

[1]

-460,924

[1]

-465,472

[1]

-460,924

[1]

'

'

Investments excluding noncontrolling interest level three rollforward

'

'

'

'

'

'

$84,996

$56,331

$84,996

$56,331

'

'

[1]

Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.

Fair_value_measurements_Narrat

Fair value measurements (Narrative) (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	$559,472		$564,448
Mutual Funds [Member]	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	9,004		8,214
Other Investments Number Of Funds	2		'
Hedge funds	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	533,345		538,526	[1]
Fund of hedge funds	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	2,450		4,757
Investment Time Lag Reporting	'1 month		'
Investments Assumed In Flagstone Acquisition [Member]	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Investment Time Lag Reporting	'1 month		'
Other Investments Number Of Funds	2		'
PaCRe funds	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Investment Time Lag Reporting	'1 month		'
Other Investments Number Of Funds	4		'
Private equity investments	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	14,673		12,951
Other Investments Number Of Funds	3		'
Fair Value, Measurements, Recurring [Member]	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	559,472		564,448
Fair Value, Measurements, Recurring [Member] | Mutual Funds [Member]	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	9,004		8,214
Fair Value, Measurements, Recurring [Member] | Hedge funds	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	533,345	[1]	538,526	[1]
Fair Value, Measurements, Recurring [Member] | Fund of hedge funds	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	2,450		4,757
Fair Value, Measurements, Recurring [Member] | Private equity investments	'		'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'		'
Other investments, at fair value	$14,673		$12,951
[1]	Included in the hedge funds balance are investments held by PaCRe in which the Company has an equity interest of 10%. The remaining 90% interest is held by third party investors.

Investments_in_affiliates_Oper

Investments in affiliates (Operating affiliates rollforward) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Activity in non-consolidated affiliate balances for the period:	'	'	'	'
Balance, beginning of period	$85,120	$86,490	$157,111	$53,031
Return of investment	-7,350	'	-86,657	'
Purchase of shares	'	'	'	26,500
Income from operating affiliates	1,463	6,235	8,779	13,194
Balance, end of period	79,233	92,725	79,233	92,725
AlphaCat Re 2011 Ltd	'	'	'	'
Activity in non-consolidated affiliate balances for the period:	'	'	'	'
Balance, beginning of period	11,054	59,238	62,792	53,031
Return of investment	-2,800	'	-54,914	'
Purchase of shares	'	'	'	0
Income from operating affiliates	-270	4,079	106	10,286
Balance, end of period	7,984	63,317	7,984	63,317
AlphaCat Re 2012 Ltd	'	'	'	'
Activity in non-consolidated affiliate balances for the period:	'	'	'	'
Balance, beginning of period	5,204	27,252	29,319	0
Return of investment	-4,550	'	-31,743	'
Purchase of shares	'	'	'	26,500
Income from operating affiliates	-7	2,156	3,071	2,908
Balance, end of period	647	29,408	647	29,408
AlphaCat 2013 Ltd	'	'	'	'
Activity in non-consolidated affiliate balances for the period:	'	'	'	'
Balance, beginning of period	48,536	'	45,000	'
Return of investment	0	'	0	'
Income from operating affiliates	585	'	4,121	'
Balance, end of period	49,121	'	49,121	'
AlphaCat ILS Funds	'	'	'	'
Activity in non-consolidated affiliate balances for the period:	'	'	'	'
Balance, beginning of period	20,326	'	20,000	'
Return of investment	0	'	0	'
Income from operating affiliates	1,155	'	1,481	'
Balance, end of period	$21,481	'	$21,481	'

Investments_in_affiliates_Oper1

Investments in affiliates (Operating affiliates - other details) (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Investment:	'	'	'	'	'	'
Investment at cost	$73,906	'	$132,889	'	'	'
Carrying value	79,233	85,120	157,111	92,725	86,490	53,031
AlphaCat Re 2011 Ltd	'	'	'	'	'	'
Investment:	'	'	'	'	'	'
Investment at cost	8,254	'	41,389	'	'	'
Voting ownership %	43.70%	'	43.70%	'	'	'
Equity ownership %	22.30%	'	22.30%	'	'	'
Carrying value	7,984	11,054	62,792	63,317	59,238	53,031
AlphaCat Re 2012 Ltd	'	'	'	'	'	'
Investment:	'	'	'	'	'	'
Investment at cost	652	'	26,500	'	'	'
Voting ownership %	49.00%	'	49.00%	'	'	'
Equity ownership %	37.90%	'	37.90%	'	'	'
Carrying value	647	5,204	29,319	29,408	27,252	0
AlphaCat 2013 Ltd	'	'	'	'	'	'
Investment:	'	'	'	'	'	'
Investment at cost	45,000	'	45,000	'	'	'
Voting ownership %	40.90%	'	40.90%	'	'	'
Equity ownership %	19.70%	'	19.70%	'	'	'
Carrying value	49,121	48,536	45,000	'	'	'
AlphaCat ILS Funds	'	'	'	'	'	'
Investment:	'	'	'	'	'	'
Investment at cost	20,000	'	20,000	'	'	'
Voting ownership %	0.00%	'	0.00%	'	'	'
Equity ownership %	9.10%	'	11.80%	'	'	'
Carrying value	$21,481	$20,326	$20,000	'	'	'

Investments_in_affiliates_Inve

Investments in affiliates (Investment affiliate) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Income (loss) from investment affiliate	$1,044		($160)		$4,274		($558)
Aquiline Financial Services Fund LP	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Investment in limited partnership (Aquiline Financial Services Fund II L.P.), beginning of period	25,352		6,317		15,218		3,253
Capital contributions	6,185		430		13,089		5,328
Net unrealized (loss) on investments	0	[1]	0	[1]	0	[1]	-1,436	[1]
Income (loss) from investment affiliate	1,044		-160		4,274		-558
Investment in limited partnership (Aquiline Financial Services Fund II L.P.), end of period	32,581		6,587		32,581		6,587
Investment in Aquiline - other details	'		'		'		'
Investment at cost	30,707		'		30,707		'
Equity ownership %	6.59%		'		6.59%		'
Carrying value	$32,581		$6,587		$32,581		$6,587
[1]	(a)Until March 31, 2012, this investment was included in " Other investments" as a level 3 investment in the fair value hierarchy, hence the change in fair value was included in net unrealized (losses) gains on investments.

Investments_in_affiliates_Text

Investments in affiliates (Text) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'	'
Income from operating affiliates	$1,463	$6,235	$8,779	$13,194	'	'	'	'
Carrying value	79,233	92,725	79,233	92,725	85,120	157,111	86,490	53,031
AlphaCat Re 2011 Ltd	'	'	'	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'	'
Equity Method Investment Voting Percentage	43.70%	'	43.70%	'	'	43.70%	'	'
Ownership percentage required for consolidation	'	'	50.00%	'	'	'	'	'
Equity ownership %	22.30%	'	22.30%	'	'	22.30%	'	'
Income from operating affiliates	-270	4,079	106	10,286	'	'	'	'
Carrying value	7,984	63,317	7,984	63,317	11,054	62,792	59,238	53,031
AlphaCat Re 2012 Ltd	'	'	'	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'	'
Equity Method Investment Voting Percentage	49.00%	'	49.00%	'	'	49.00%	'	'
Equity ownership %	37.90%	'	37.90%	'	'	37.90%	'	'
Income from operating affiliates	-7	2,156	3,071	2,908	'	'	'	'
Carrying value	647	29,408	647	29,408	5,204	29,319	27,252	0
AlphaCat 2013 Ltd	'	'	'	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'	'
Equity Method Investment Voting Percentage	40.90%	'	40.90%	'	'	40.90%	'	'
Equity ownership %	19.70%	'	19.70%	'	'	19.70%	'	'
Income from operating affiliates	585	'	4,121	'	'	'	'	'
Carrying value	49,121	'	49,121	'	48,536	45,000	'	'
Investment in ILS Funds	'	'	'	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'	'
Other Investments Number Of Funds	3	'	3	'	'	'	'	'
Third party subscriptions	'	'	'	'	'	219,400	'	'
AlphaCat ILS Funds	'	'	'	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'	'
Additional Third Party Subscriptions	13,000	'	82,190	'	'	'	'	'
Equity Method Investment Voting Percentage	0.00%	'	0.00%	'	'	0.00%	'	'
Equity ownership %	9.10%	'	9.10%	'	'	11.80%	'	'
Income from operating affiliates	1,155	'	1,481	'	'	'	'	'
Carrying value	21,481	'	21,481	'	20,326	20,000	'	'
Aquiline Financial Services Fund LP	'	'	'	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'	'
Equity Method Investment Voting Percentage	0.00%	'	0.00%	'	'	'	'	'
Equity ownership %	6.59%	'	6.59%	'	'	'	'	'
Investment Time Lag Reporting	'	'	'3 months	'	'	'	'	'
Percentage of Assignor's interest assumed	'	'	100.00%	'	'	'	'	'
Total capital commitment	'	'	$50,000	'	'	'	'	'
Variable interest entity, not primary beneficiary | Investment in ILS Funds	'	'	'	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'	'	'	'
Other Investments Number Of Funds	2	'	2	'	'	'	'	'

Noncontrolling_interest_Detail

Noncontrolling interest (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

PaCRe, Ltd

PaCRe, Ltd

PaCRe, Ltd

PaCRe, Ltd

AlphaCat ILS Funds

AlphaCat ILS Funds

Investment in ILS Funds

Investment in ILS Funds

PaCRe funds

PaCRe funds

Variable interest entity, not primary beneficiary

funds

funds

Investment in ILS Funds

funds

Noncontrolling Interest [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Additional capital contributions from Validus Re to PaCRe

'

'

'

'

$6,500

'

'

'

'

'

'

'

'

'

'

Noncontrolling Interest, Ownership Percentage by Parent

'

'

'

'

'

'

'

'

'

'

'

'

10.00%

10.00%

'

Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners

'

'

'

'

'

'

'

'

'

'

'

'

90.00%

90.00%

'

Third party subscriptions

'

'

'

'

'

'

'

'

'

'

'

219,400

'

'

'

Other Investments Number Of Funds

'

'

'

'

'

'

'

'

'

'

3

'

4

'

2

Activity in net income attributable to noncontrolling interest

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance - Beginning of Period

498,445

404,740

434,280

0

427,755

404,740

434,280

0

70,690

0

'

'

'

'

'

Purchase of shares by noncontrolling interest

13,000

'

140,690

450,100

0

'

58,500

450,100

13,000

82,190

'

'

'

'

'

Net (income) loss attributable to noncontrolling interest

45,694

56,746

-17,831

11,386

44,178

56,746

-20,847

11,386

1,516

3,016

'

'

'

'

'

Balance - End of Period

$557,139

$461,486

$557,139

$461,486

$471,933

$461,486

$471,933

$461,486

$85,206

$85,206

'

'

'

'

'

Derivative_instruments_Derivat

Derivative instruments Derivative instruments not designated as hedging instruments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Currency swap | Not Designated as Hedging Instrument [Member]	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Derivative, Notional Amount	$0	$17,153
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Derivative, Notional Amount	0	310,541
Accounts Payable and Accrued Liabilities [Member] | Currency swap | Not Designated as Hedging Instrument [Member]	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Derivative Liability, Fair Value, Gross Liability	0	772
Accounts Payable and Accrued Liabilities [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Derivative Liability, Fair Value, Gross Liability	0	394
Other Assets [Member] | Currency swap | Not Designated as Hedging Instrument [Member]	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	0	'
Other Assets [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	$0	'
Junior Subordinated Deferrable Debentures [Member] | Interest rate swap contracts	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Number of derivative instruments held	2	'
Flagstone Junior Subordinated Deferrable Debentures [Member] | Interest rate swap contracts	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Number of derivative instruments held	3	'
Flagstone Junior Subordinated Deferrable Debentures [Member] | Cross Currency Interest Rate Contract [Member]	'	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'	'
Number of derivative instruments held	1	'

Derivative_instruments_used_in1

Derivative instruments used in hedging activities (Amount and balance sheet location) (Details) (Designated as hedging instruments, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Foreign exchange contracts	'	'
Summary of amount of derivatives designated as hedging instruments	'	'
Notional amount	$168,722	$35,976
Foreign exchange contracts | Other assets	'	'
Summary of amount of derivatives designated as hedging instruments	'	'
Derivative Asset, Fair Value, Gross Asset	4,977	0
Foreign exchange contracts | Accounts Payable and Accrued Liabilities [Member]	'	'
Summary of amount of derivatives designated as hedging instruments	'	'
Fair value, derivative liabilities	1,115	223
Interest rate swap contracts	'	'
Summary of amount of derivatives designated as hedging instruments	'	'
Notional amount	552,263	289,800
Interest rate swap contracts | Other assets	'	'
Summary of amount of derivatives designated as hedging instruments	'	'
Derivative Asset, Fair Value, Gross Asset	0	0
Interest rate swap contracts | Accounts Payable and Accrued Liabilities [Member]	'	'
Summary of amount of derivatives designated as hedging instruments	'	'
Fair value, derivative liabilities	$873	$220

Derivative_instruments_used_in2

Derivative instruments used in hedging activities (Amount included in statement of operations) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Foreign Currency Gain (Loss) [Member]	'	'	'	'
Derivatives designated as fair value hedges and related hedged item	'	'	'	'
Amount of gain (loss) recognized in income on derivative	$3,116	$1,749	$2,670	$130
Amount of gain (loss) on hedged item recognized in income attributable to risk being hedged	-3,116	-1,749	-2,670	-130
Amount of gain (loss) recognized in income on derivative (ineffective portion)	0	0	0	0
Cash flow hedge | Interest rate swap contracts	'	'	'	'
Derivative instruments designated as a cash flow hedge	'	'	'	'
Amount of ineffective portion excluded from effectiveness testing	0	0	0	0
Cash flow hedge | Interest rate swap contracts | Other comprehensive income	'	'	'	'
Derivative instruments designated as a cash flow hedge	'	'	'	'
Amount of effective portion recognized in other comprehensive income	3,268	195	7,838	195
Cash flow hedge | Interest rate swap contracts | Finance expenses	'	'	'	'
Derivative instruments designated as a cash flow hedge	'	'	'	'
Amount of effective portion subsequently reclassified to earnings	($3,268)	($195)	($7,838)	($195)

Reserve_for_losses_and_loss_ex2

Reserve for losses and loss expenses (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reserve for paid losses and unpaid loss expenses	'	'	'	'
Reserve for losses and loss expenses, beginning of period	$3,283,450	$2,591,299	$3,517,573	$2,631,143
Losses and loss expenses recoverable, beginning of period	-418,693	-371,484	-439,967	-372,485
Net reserves for losses and loss expenses, beginning of period	2,864,757	2,219,815	3,077,606	2,258,658
Net reserves acquired	'	'	948	0
Increase (decrease) in net losses and loss expenses incurred in respect of losses occurring in:	'	'	'	'
Current year	243,015	205,219	759,617	658,884
Prior years	-65,050	-49,764	-171,837	-117,748
Total incurred losses and loss expenses	177,965	155,455	587,780	541,136
Total net paid losses	-274,868	-144,628	-847,192	-569,380
Foreign exchange	34,363	14,710	-16,925	14,938
Net reserve for losses and loss expenses, end of period	2,802,217	2,245,352	2,802,217	2,245,352
Losses and loss expenses recoverable, end of period	421,518	317,252	421,518	317,252
Reserve for losses and loss expenses, end of period	$3,223,735	$2,562,604	$3,223,735	$2,562,604

Reinsurance_Details

Reinsurance (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	$451,592	$486,402
Percentage of reinsurance recoverables	100.00%	100.00%
Reinsurance (Textuals) [Abstract]	'	'
Incurred but not reported recoverable	211,864	185,255
Provision for uncollectible reinsurance relating to losses recoverable	6,209	6,602
A- or better	'	'
Ceded Credit Risk [Line Items]	'	'
Percentage of reinsurance recoverables	97.70%	97.90%
Fully Collateralized Reinsurers	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	34,293	47,445
Top 10 reinsurers	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	340,988	360,234
Percentage of reinsurance recoverables	75.50%	74.10%
Percentage of top 10 reinsurers reinsurance recoverables	100.00%	100.00%
Top 10 reinsurers | Lloyd's Syndicates | A plus	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	74,586	71,469
Percentage of top 10 reinsurers reinsurance recoverables	21.90%	19.90%
Top 10 reinsurers | National Indemnity | AA plus	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	50,984	59,941
Percentage of top 10 reinsurers reinsurance recoverables	14.90%	16.60%
Top 10 reinsurers | Everest Re | A plus	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	52,372	51,340
Percentage of top 10 reinsurers reinsurance recoverables	15.30%	14.30%
Top 10 reinsurers | Hannover Re | AA-	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	45,975	40,552
Percentage of top 10 reinsurers reinsurance recoverables	13.50%	11.30%
Top 10 reinsurers | Fully Collateralized Reinsurers | NR	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	34,293	47,445
Percentage of top 10 reinsurers reinsurance recoverables	10.10%	13.20%
Top 10 reinsurers | Transatlantic Re | A plus	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	15,887	20,320
Percentage of top 10 reinsurers reinsurance recoverables	4.70%	5.60%
Top 10 reinsurers | Swiss Re | AA-	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	20,728	16,992
Percentage of top 10 reinsurers reinsurance recoverables	6.10%	4.70%
Top 10 reinsurers | XL Re | A	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	14,062	14,854
Percentage of top 10 reinsurers reinsurance recoverables	4.10%	4.10%
Top 10 reinsurers | Third Point Re [Member] | A-	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	20,049	'
Percentage of top 10 reinsurers reinsurance recoverables	5.90%	'
Top 10 reinsurers | Munich Re | AA-	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	12,052	20,954
Percentage of top 10 reinsurers reinsurance recoverables	3.50%	5.80%
Top 10 reinsurers | Allianz | AA-	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	'	16,367
Percentage of top 10 reinsurers reinsurance recoverables	'	4.50%
Other reinsurers' balances greater than $1 million	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	102,714	115,262
Percentage of reinsurance recoverables	22.70%	23.70%
Other reinsurers' balances less than $1 million	'	'
Ceded Credit Risk [Line Items]	'	'
Reinsurance recoverable	$7,890	$10,906
Percentage of reinsurance recoverables	1.80%	2.20%

Share_capital_Details

Share capital (Details) (USD $)

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

In Thousands, except Share data, unless otherwise specified

Feb. 06, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Nov. 30, 2012

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Flagstone Reinsurance Holdings Sa [Member]

Common shares

Common shares

Common shares

Common shares

Common shares

Common shares

Common shares

Common share equivalents

Common share equivalents

Common share equivalents

Common share equivalents

Performance shares

Warrants

Warrants

Warrants

Warrants

Deferred share units

Restricted share awards

Restricted share awards

Restricted share units

Restricted share units

Employee director

Special dividend declared

Special dividend declared

Deferred share units

Schedule of Common Stock Issued and Outstanding [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of warrants exercised during period

'

'

'

'

'

'

'

1,114,416

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

163,772

264,127

264,127

'

'

'

'

'

'

'

Stock Issued During Period, Shares, Conversion of Convertible Securities

'

'

'

'

'

'

'

'

'

'

'

83,287

'

'

130,121

591,480

130,121

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Class of Warrant or Right, Outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,296,056

'

'

6,410,472

'

'

'

'

'

'

Summary of common shares issued and outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common shares issued, beginning balance

'

'

'

152,698,191

'

'

134,503,065

152,698,191

134,503,065

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vested, net of shares withheld

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

31,897

'

'

'

'

'

768,889

1,545,024

14,381

15,173

'

Options exercised (in shares)

'

'

'

'

'

'

'

277,615

439,065

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Direct issuance of common stock

'

'

'

'

'

'

'

928

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred share units vested, net of shares withheld

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,935

'

'

'

'

2,935

Common shares issued, ending balance

'

154,386,316

'

'

136,632,448

'

'

154,386,316

136,632,448

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares repurchased, ending balance

'

-54,488,320

'

'

-43,138,057

'

'

-54,488,320

-43,138,057

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common shares outstanding, ending balance

'

99,897,996

'

'

93,494,391

'

'

99,897,996

93,494,391

107,921,259

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share repurchases

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Repurchase Program, Authorized Amount

$500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share repurchase program, cumulative shares repurchased

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

52,849,445

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares repurchased, cumulative

1,206,845

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,564,029

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Remaining share repurchase authorization amount

'

'

'

'

'

'

'

$142,816

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Treasury Stock, Shares, Acquired

'

'

'

'

'

'

'

'

'

'

1,638,875

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share Capital (Texts)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common shares, shares authorized

'

571,428,571

'

'

'

'

'

571,428,571

'

571,428,571

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common shares, par value

'

$0.18

'

'

'

'

'

$0.18

'

$0.18

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock voting rights

'

'

'

'

'

'

'

'one vote per share

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restriction on percentage of voting power

'

'

'

'

'

'

'

9.09%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition Equity Interests Issued Or Issuable Number Of Shares Issued Net Of Shares Withheld

'

'

'

'

'

'

'

'

'

'

14,202,664

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Cost of Acquired Entity, Equity Interests Withheld For Income Taxes

'

'

'

'

'

'

'

'

'

'

87,725

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Treasury Stock, Shares, Acquired

'

'

'

'

'

'

'

'

'

'

1,638,875

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Closing Price Per Share Of Companys Stock

'

'

'

'

'

'

'

'

'

'

$34.87

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination Acquired Warrants

'

'

'

'

'

'

'

'

'

'

121,942

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrant strike price

'

'

'

'

'

'

'

'

'

'

62.02

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred share units, adjustment factor

'

'

'

'

'

'

'

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total outstanding deferred share units

'

0

'

'

'

'

'

0

'

5,001

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vested (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

39,094

'

'

'

'

'

930,296

1,678,905

21,814

22,818

5,039

Date of dividend declaration

'

30-Jul-13

1-May-13

6-Feb-13

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash dividends declared per share

'

$0.30

'

'

$0.25

$0.25

$0.25

$2.90

$0.75

'

'

$0.30

$0.30

$0.30

'

'

'

$2

$0.30

$0.30

$0.30

$2

'

'

'

'

'

'

'

'

'

'

'

Stock_plans_Options_activity_D

Stock plans (Options activity) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Options activities:	'	'
Options outstanding, beginning balance (in shares)	1,823,947	2,263,012
Options regranted (modified) (in shares)	1,833,414	'
Options exercised (in shares)	-277,615	-439,065
Options cancelled (modified) (in shares)	-1,733,139	'
Options outstanding, ending balance (in shares)	1,646,607	1,823,947
Options exercisable (in shares)	1,646,607	1,823,947
Weighted Average Grant Date Fair Value	'	'
Weighted average grant date fair value, beginning balance (in dollars per share)	$6.52	$6.69
Weighted average grant date fair value, options regranted (modified) (in dollars per share)	$6.76	'
Weighted average grant date fair value, options exercised (in dollars per share)	$5.24	$7.44
Weighted average grant date fair value, options cancelled (modified) (in dollars per share)	$6.76	'
Weighted average grant date fair value, ending balance (in dollars per share)	$6.75	$6.52
Weighted average grant date fair value, options exercisable (in dollars per share)	$6.75	$6.52
Weighted Average Grant Date Exercise Price	'	'
Weighted average grant date exercise price, beginning balance (in dollars per share)	$20.69	$20.12
Weighted average grant date exercise price, options regranted (repriced) (in dollars per share)	$19.02	'
Weighted average grant date exercise price, options exercised (in dollars per share)	$23.58	$17.73
Weighted average grant date exercise price, options cancelled (repriced) (in dollars per share)	$20.12	'
Weighted average grant date exercise price, ending balance (in dollars per share)	$18.94	$20.69
Weighted average grant date exercise price, options exercisable (in dollars per share)	$18.94	$20.69

Stock_plans_Other_awards_activ

Stock plans (Other awards activity) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Restricted share awards	'	'
Activities	'	'
Beginning balance (in shares)	2,170,547	3,003,547
Granted (in shares)	1,580,117	901,506
Vested (in shares)	-930,296	-1,678,905
Forfeited (in shares)	-110,912	-30,801
Ending balance (in shares)	2,709,456	2,195,347
Weighted average grant date fair value	'	'
Weighted average grant date fair value, beginning balance (in dollars per share)	$29.24	$25.77
Weighted average grant date fair value, granted (in dollars per share)	$36.06	$31.38
Weighted average grant date fair value, vested (in dollars per share)	$28.08	$24.36
Weighted average grant date fair value, forfeited (in dollars per share)	$28.34	$28.10
Weighted average grant date fair value, ending balance (in dollars per share)	$33.65	$29.12
Restricted share units	'	'
Activities	'	'
Beginning balance (in shares)	47,238	53,312
Granted (in shares)	36,635	16,633
Vested (in shares)	-21,814	-22,818
Issued in lieu of cash dividends (in shares)	3,924	1,162
Forfeited (in shares)	'	-1,393
Ending balance (in shares)	65,983	46,896
Weighted average grant date fair value	'	'
Weighted average grant date fair value, beginning balance (in dollars per share)	$29.61	$27.60
Weighted average grant date fair value, granted (in dollars per share)	$36.11	$31.77
Weighted average grant date fair value, vested (in dollars per share)	$28.17	$26.49
Weighted average grant date fair value, issued in lieu of cash dividends (in dollars per share)	$30.29	$28.36
Weighted average grant date fair value, forfeited (in dollars per share)	'	$28.57
Weighted average grant date fair value, ending balance (in dollars per share)	$33.74	$29.61
Performance shares	'	'
Activities	'	'
Beginning balance (in shares)	220,845	279,019
Granted (in shares)	38,386	41,128
Vested (in shares)	-39,094	'
Forfeited (in shares)	-18,701	-99,302
Conversion adjustment (in shares)	-99,616	'
Ending balance (in shares)	101,820	220,845
Weighted average grant date fair value	'	'
Weighted average grant date fair value, beginning balance (in dollars per share)	$31.81	$30.77
Weighted average grant date fair value, granted (in dollars per share)	$36.11	$31.38
Weighted average grant date fair value, vested (in dollars per share)	$28.70	'
Weighted average grant date fair value, forfeited (in dollars per share)	$31.05	$28.70
Weighted average grant date fair value, conversion adjustment (in dollars per share)	$33.05	'
Weighted average grant date fair value, ending balance (in dollars per share)	$33.56	$31.81

Stock_plans_Components_of_shar

Stock plans (Components of share compensation expenses) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Total share compensation expenses	'	'	'	'
Share compensation expenses	$10,527	$7,345	$19,483	$19,583
Options	'	'	'	'
Total share compensation expenses	'	'	'	'
Share compensation expenses	0	0	0	142
Restricted share awards	'	'	'	'
Total share compensation expenses	'	'	'	'
Share compensation expenses	10,041	6,626	20,035	18,742
Restricted share units	'	'	'	'
Total share compensation expenses	'	'	'	'
Share compensation expenses	168	132	419	363
Performance shares	'	'	'	'
Total share compensation expenses	'	'	'	'
Share compensation expenses	$318	$587	($971)	$336

Stock_plans_Text_Details

Stock plans (Text) (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Stock plans (other details)	'	'	'	'	'
Number of shares reserved for issuance under the LTIP and STIP	13,126,896	'	13,126,896	'	'
Remaining number of shares reserved for issuance	1,783,462	'	1,783,462	'	'
Share compensation expenses	$10,527	$7,345	$19,483	$19,583	'
Options	'	'	'	'	'
Stock plans (other details)	'	'	'	'	'
Life of options	'	'	'10 years	'	'
Share compensation expenses	0	0	0	142	'
Weighted average period of recognizing share based compensation expenses	'	'	'0 years	'	'0 years
Restricted share awards	'	'	'	'	'
Stock plans (other details)	'	'	'	'	'
Share compensation expenses	10,041	6,626	20,035	18,742	'
Unrecognized share compensation expenses	76,084	'	76,084	'	43,952
Weighted average period of recognizing share based compensation expenses	'	'	'3 years 4 months 24 days	'	'2 years 7 months 6 days
Restricted share units	'	'	'	'	'
Stock plans (other details)	'	'	'	'	'
Share compensation expenses	168	132	419	363	'
Unrecognized share compensation expenses	1,839	'	1,839	'	978
Weighted average period of recognizing share based compensation expenses	'	'	'3 years 6 months 0 days	'	'2 years 7 months 6 days
Performance shares	'	'	'	'	'
Stock plans (other details)	'	'	'	'	'
Share compensation expenses	318	587	-971	336	'
Unrecognized share compensation expenses	$1,893	'	$1,893	'	3,328
Weighted average period of recognizing share based compensation expenses	'	'	'2 years 2 months 12 days	'	'1 year 8 months 12 days
Performance share awards performance period	'	'	'3 years	'	'

Debt_and_financing_arrangement2

Debt and financing arrangements (Schedule of finance structure) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'		'
Credit facility, commitment	$1,575,000		$2,090,000
Long-term debt, drawn	788,298		787,799
Debt Instrument And Line Of Credit Facility Amount Committed	2,426,327		2,940,909
Debt Instrument And Line Of Credit Facility Amount Outstanding	1,590,016	[1]	1,706,532	[1]
Flagstone BiLateral Facility	'		'
Debt Instrument [Line Items]	'		'
Credit facility, commitment	375,000		550,000
Guarantor Obligations, Maximum Exposure, Undiscounted	297,996	[1]	381,019	[1]
Ipc Bi Lateral Facility [Member]	'		'
Debt Instrument [Line Items]	'		'
Credit facility, commitment	40,000	[1]	80,000	[1]
Guarantor Obligations, Maximum Exposure, Undiscounted	26,019	[1]	40,613	[1]
PaCRe Senior secured letter of credit facility	'		'
Debt Instrument [Line Items]	'		'
Credit facility, commitment	10,000		10,000
Guarantor Obligations, Maximum Exposure, Undiscounted	258	[1]	219	[1]
Talbot Fal Facility [Member]	'		'
Debt Instrument [Line Items]	'		'
Credit facility, commitment	25,000	[2]	25,000	[2]
Guarantor Obligations, Maximum Exposure, Undiscounted	25,000	[1],[2]	25,000	[1],[2]
Secured Bi-Lateral Facility [Member]	'		'
Debt Instrument [Line Items]	'		'
Credit facility, commitment	200,000		500,000
Guarantor Obligations, Maximum Exposure, Undiscounted	77,626	[1]	92,402	[1]
Four Year Secured Credit Facility [Member]	'		'
Debt Instrument [Line Items]	'		'
Credit facility, commitment	525,000		525,000
Guarantor Obligations, Maximum Exposure, Undiscounted	371,990	[1]	376,570	[1]
Four Year Unsecured Credit Facility [Member]	'		'
Debt Instrument [Line Items]	'		'
Credit facility, commitment	400,000		400,000
Guarantor Obligations, Maximum Exposure, Undiscounted	0	[1]	0	[1]
Senior Notes Two Thousand Ten Due Two Thousand Forty [Member]	'		'
Debt Instrument [Line Items]	'		'
Debt instrument, outstanding	250,000	[1]	250,000	[1]
Long-term debt, drawn	247,171		247,090
Debt Instrument, Face Amount	250,000		250,000
Flagstone 2006 Junior Subordinated Deferrable Interest Notes	'		'
Debt Instrument [Line Items]	'		'
Debt instrument, outstanding	137,577	[1]	137,159	[1]
Long-term debt, drawn	137,577		137,159
Debt Instrument, Face Amount	137,577		137,159
Flagstone 2007 Junior Subordinated Deferrable Interest Notes	'		'
Debt Instrument [Line Items]	'		'
Debt instrument, outstanding	113,750	[1]	113,750	[1]
Long-term debt, drawn	113,750		113,750
Debt Instrument, Face Amount	113,750		113,750
Junior Subordinated Deferrable Debentures Two Thousand Seven [Member]	'		'
Debt Instrument [Line Items]	'		'
Debt instrument, outstanding	139,800	[1]	139,800	[1]
Long-term debt, drawn	139,800		139,800
Debt Instrument, Face Amount	200,000		200,000
Junior Subordinated Deferrable Debentures Two Thousand Six [Member]	'		'
Debt Instrument [Line Items]	'		'
Debt instrument, outstanding	150,000	[1]	150,000	[1]
Long-term debt, drawn	150,000		150,000
Debt Instrument, Face Amount	$150,000		$150,000
[1]	Indicates utilization of commitment amount, not drawn borrowings.
[2]	Talbot operates in the Lloyd’s market ("Lloyds") through a corporate member, Talbot 2002 Underwriting Capital Ltd (“T02”), which is the sole participant in Syndicate 1183. Lloyd’s sets T02’s required capital annually based on Syndicate 1183’s business plan, rating environment, reserving environment together with input arising from Lloyd’s discussions with, inter alia, regulatory and rating agencies. Such capital, called Funds at Lloyd’s (“FAL”), comprises: cash, investments and undrawn letters of credit provided by various banks.

Recovered_Sheet1

Debt and financing Arrangements (Components of finance expenses) (Details) (USD $)	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	$27,132		$9,362	$89,408		$39,347
AlphaCat Variable Funding Notes [Member]	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	11,893	[1]	0	44,562	[1]	0
Credit Facilities [Member]	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	1,248		948	5,001		10,530
Bank charges [Member]	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	187		-52	419		131
Talbot Fal Facility [Member]	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	32		30	95		93
Junior Subordinated Deferrable Debentures Two Thousand Six [Member]	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	2,235		1,628	6,633		4,729
Junior Subordinated Deferrable Debentures Two Thousand Seven [Member]	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	1,848		1,211	5,492		7,072
Senior Notes Two Thousand Ten Due Two Thousand Forty [Member]	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	5,597		5,597	16,792		16,792
Flagstone 2006 Junior Subordinated Deferrable Interest Notes	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	2,285		0	5,988		0
Flagstone 2007 Junior Subordinated Deferrable Interest Notes	'		'	'		'
Debt Instrument [Line Items]	'		'	'		'
Financing Interest Expense	$1,807		$0	$4,426		$0
[1]	Includes variable funding note expense and other AlphaCat related fees. Refer to Note 13: "Variable funding notes" for further details.

Recovered_Sheet2

Debt and financing Arrangements (Future payments of principal) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Future expected payments of principal	'	'
Total minimum future payments	$541,127	$540,709
2010 Senior Notes Due 2040	'	'
Future expected payments of principal	'	'
2013	0	'
2014	0	'
2015	0	'
2016	0	'
2017 and thereafter	250,000	'
Total minimum future payments	250,000	'
Junior subordinated deferrable debentures	'	'
Future expected payments of principal	'	'
2013	0	'
2014	0	'
2015	0	'
2016	0	'
2017 and thereafter	540,709	'
Total minimum future payments	$540,709	'

Recovered_Sheet3

Debt and financing Arrangements (Text) (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Senior Notes and Junior Debentures	'		'
Long-term debt, drawn	$788,298		$787,799
Credit Facilities	'		'
Credit facility, commitment	1,575,000		2,090,000
Credit Facilities	'		'
Credit Facilities	'		'
Minimum level of consolidated net worth	2,600,000		'
Percent of consolidated net income quarterly increase under covenant	50.00%		'
Percent of any net proceeds from issuance of common shares	50.00%		'
Ratio consolidated total debt to net worth under covenant	'0.35:1.00		'
Four-year syndicated unsecured credit facility	'		'
Credit Facilities	'		'
Credit facility, commitment	400,000		400,000
Letter of credit facility period	'4 years		'
Letter of credit facility amount issued and outstanding	0	[1]	0	[1]
Line of credit facility initiation date	9-Mar-12		'
Description of interest rate basis	'The borrowings bear interest, at the option of the Company, at the base rate (the higher of the prime rate announced by JPMorgan Chase Bank, the federal funds effective rate plus 0.50%, and the adjusted LIBOR rate plus 1.0%) or the adjusted LIBOR rate applicable to such loans, plus an applicable rate.		'
Four-year syndicated secured credit facility	'		'
Credit Facilities	'		'
Credit facility, commitment	525,000		525,000
Letter of credit facility period	'4 years		'
Aggregate commitments, maximum	700,000		'
Letter of credit facility amount issued and outstanding	371,990	[1]	376,570	[1]
Line of credit facility initiation date	9-Mar-12		'
Description of interest rate basis	'The borrowings bear interest at the base rate (the higher of the prime rate announced by JPMorgan Chase Bank, NA, the federal funds effective rate plus 0,50%, and the adjusted LIBOR rate plus 1.0%).		'
Four-year syndicated secured credit facility | Maximum	'		'
Credit Facilities	'		'
Basis spread on variable rate	0.01		'
Four-year syndicated secured credit facility | Minimum	'		'
Credit Facilities	'		'
Basis spread on variable rate	0.005		'
Syndicated unsecured letter of credit facility	'		'
Credit Facilities	'		'
Credit facility, commitment	400,000		400,000
Aggregate commitments, maximum	500,000		'
Syndicated unsecured letter of credit facility | Maximum	'		'
Credit Facilities	'		'
Basis spread on variable rate	0.01		'
Syndicated unsecured letter of credit facility | Minimum	'		'
Credit Facilities	'		'
Basis spread on variable rate	0.005		'
Bilateral unsecured letter of credit facility | Terminated Credit Facilities [Member]	'		'
Credit Facilities	'		'
Credit facility, commitment	60,000		'
Letter of credit facility period	'3 years		'
Three year unsecured letter of credit facility | Terminated Credit Facilities [Member]	'		'
Credit Facilities	'		'
Credit facility, commitment	340,000		'
Letter of credit facility period	'3 years		'
Five year secured letter of credit facility	'		'
Credit Facilities	'		'
Credit facility, commitment	525,000		525,000
Five year secured letter of credit facility | Terminated Credit Facilities [Member]	'		'
Credit Facilities	'		'
Credit facility, commitment	500,000		'
Letter of credit facility period	'5 years		'
Talbot FAL Facility	'		'
Credit Facilities	'		'
Credit facility, commitment	25,000	[2]	25,000	[2]
Letter of credit facility amount issued and outstanding	25,000	[1],[2]	25,000	[1],[2]
Letter of credit facility, original commitment amount	100,000		'
Line of credit facility initiation date	29-Nov-07		'
Minimum level of consolidated net worth	2,589,615		'
Percent of consolidated net income quarterly increase under covenant	50.00%		'
Percent of any net proceeds from issuance of common shares	50.00%		'
Ratio consolidated total debt to net worth under covenant	'0.35:1.00		'
IPC Bi Lateral Facility	'		'
Credit Facilities	'		'
Credit facility, commitment	40,000	[1]	80,000	[1]
Letter of credit facility amount issued and outstanding	26,019	[1]	40,613	[1]
Bi-lateral secured facility	'		'
Credit Facilities	'		'
Credit facility, commitment	200,000		500,000
Letter of credit facility amount issued and outstanding	77,626	[1]	92,402	[1]
Line of credit facility initiation date	10-Aug-09		'
PaCRe Senior secured letter of credit facility	'		'
Credit Facilities	'		'
Credit facility, commitment	10,000		10,000
Letter of credit facility period	'364 days		'
Letter of credit facility amount issued and outstanding	258	[1]	219	[1]
Line of credit facility initiation date	11-May-12		'
Flagstone BiLateral Facility	'		'
Credit Facilities	'		'
Credit facility, commitment	375,000		550,000
Letter of credit facility amount issued and outstanding	297,996	[1]	381,019	[1]
2006 Junior Subordinated Deferrable Debentures	'		'
Senior Notes and Junior Debentures	'		'
Debt instrument issuance date	15-Jun-06		'
Debt instrument maturity date	15-Jun-36		'
Frequency of required payments	'quarterly		'
Debt issuance cost	3,750		'
Length of optional redemption period	'5 years		'
Debt instrument, outstanding	150,000	[1]	150,000	[1]
Debt instrument, commitment	150,000		150,000
Long-term debt, drawn	150,000		150,000
Start of optional redemption period	15-Jun-11		'
Gross proceeds on issuance of junior subordinated deferrable debentures	150,000		'
2007 Junior Subordinated Deferrable Debentures	'		'
Senior Notes and Junior Debentures	'		'
Debt instrument issuance date	21-Jun-07		'
Debt instrument maturity date	15-Jun-37		'
Frequency of required payments	'quarterly		'
Debt issuance cost	2,000		'
Length of optional redemption period	'5 years		'
Debt instrument, outstanding	139,800	[1]	139,800	[1]
Debt instrument, commitment	200,000		200,000
Long-term debt, drawn	139,800		139,800
Start of optional redemption period	15-Jun-12		'
Gross proceeds on issuance of junior subordinated deferrable debentures	200,000		'
2010 Senior Notes Due 2040	'		'
Senior Notes and Junior Debentures	'		'
Debt instrument maturity date	26-Jan-40		'
Interest rate	8.88%		'
Frequency of required payments	'semi-annually		'
Net proceeds on issuance of senior notes	243,967		'
Debt issuance cost	2,808		'
Debt instrument, outstanding	250,000	[1]	250,000	[1]
Debt instrument, commitment	250,000		250,000
Long-term debt, drawn	247,171		247,090
Flagstone 2006 Junior Subordinated Deferrable Interest Notes	'		'
Senior Notes and Junior Debentures	'		'
Debt instrument maturity date	15-Sep-36		'
Frequency of required payments	'quarterly		'
Description of variable rate basis	'three-month LIBOR		'
Basis spread on variable rate	3.54%		'
Debt instrument, outstanding	137,577	[1]	137,159	[1]
Debt instrument, commitment	137,577		137,159
Long-term debt, drawn	137,577		137,159
Start of optional redemption period	15-Sep-11		'
Flagstone 2007 Junior Subordinated Deferrable Interest Notes	'		'
Senior Notes and Junior Debentures	'		'
Debt instrument, outstanding	113,750	[1]	113,750	[1]
Debt instrument, commitment	113,750		113,750
Long-term debt, drawn	113,750		113,750
Senior Notes Two Thousand Ten Due Two Thousand Forty [Member]	'		'
Senior Notes and Junior Debentures	'		'
Debt instrument issuance date	21-Jan-10		'
Date of first required payment	26-Jul-10		'
Jun 15 2006 - Jun 15 2011 | 2006 Junior Subordinated Deferrable Debentures	'		'
Senior Notes and Junior Debentures	'		'
Interest rate	9.07%		'
Jun 21 2007 - Jun 15 2012 | 2007 Junior Subordinated Deferrable Debentures	'		'
Senior Notes and Junior Debentures	'		'
Interest rate	8.48%		'
Jun 15 2011 - Jun 15 2036 | 2006 Junior Subordinated Deferrable Debentures	'		'
Senior Notes and Junior Debentures	'		'
Description of variable rate basis	'three-month LIBOR		'
Basis spread on variable rate	3.55%		'
Jun 15 2012 - Jun 15 2037 | 2007 Junior Subordinated Deferrable Debentures	'		'
Senior Notes and Junior Debentures	'		'
Description of variable rate basis	'three-month LIBOR		'
Basis spread on variable rate	2.95%		'
Flagstone 2007 Due July 30 2037 | Flagstone 2007 Junior Subordinated Deferrable Interest Notes	'		'
Senior Notes and Junior Debentures	'		'
Frequency of required payments	'quarterly		'
Description of variable rate basis	'three-month LIBOR		'
Basis spread on variable rate	3.00%		'
Debt instrument, commitment	88,750		'
Debt Instrument, September 15, 2037 Maturity Date	30-Jul-37		'
Start of optional redemption period	30-Jul-12		'
Flagstone 2007 Debt Due September 15 2037 | Flagstone 2007 Junior Subordinated Deferrable Interest Notes	'		'
Senior Notes and Junior Debentures	'		'
Frequency of required payments	'quarterly		'
Description of variable rate basis	'three-month LIBOR		'
Basis spread on variable rate	3.10%		'
Debt instrument, commitment	$25,000		'
Start of optional redemption period	15-Sep-12		'
Debt Instrument, July 30, 2037 Maturity Date	15-Sep-37		'
[1]	Indicates utilization of commitment amount, not drawn borrowings.
[2]	Talbot operates in the Lloyd’s market ("Lloyds") through a corporate member, Talbot 2002 Underwriting Capital Ltd (“T02”), which is the sole participant in Syndicate 1183. Lloyd’s sets T02’s required capital annually based on Syndicate 1183’s business plan, rating environment, reserving environment together with input arising from Lloyd’s discussions with, inter alia, regulatory and rating agencies. Such capital, called Funds at Lloyd’s (“FAL”), comprises: cash, investments and undrawn letters of credit provided by various banks.

Variable_funding_notes_Details

Variable funding notes (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]	'	'
Variable funding notes	$437,970	$0
Variable interest entity, not primary beneficiary	'	'
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]	'	'
Variable funding notes	437,970	'
Variable interest entity, not primary beneficiary | AlphaCat 2013 Ltd	'	'
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]	'	'
Variable funding notes	214,639	'
Variable interest entity, not primary beneficiary | AlphaCat ILS Funds	'	'
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]	'	'
Variable funding notes	$223,331	'

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Balance, beginning of period	'	'	($2,953)	'
Foreign currency translation adjustments	4,390	1,400	-5,209	2,036
Balance, end of period	-3,872	'	-3,872	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Translation Adjustment [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Balance, beginning of period	-8,262	'	-2,953	'
Amounts reclassified from/to accumulated other comprehensive income	0	'	4,290	'
Foreign currency translation adjustments	4,390	'	-5,209	'
Balance, end of period	($3,872)	'	($3,872)	'

Commitments_and_contingencies_

Commitments and contingencies (Investment portfolio) (Details) (Concentrations of credit risk)	9 Months Ended
	Sep. 30, 2013
Investment portfolio excluding government and agency securities	'
Concentrations Of Credit Risk [Abstract]	'
Maximum aggregate exposure to single issuer, allowed	3.00%
Aggregate exposure to single issuer, actual	1.00%
Investment portfolio excluding bank loans	'
Concentrations Of Credit Risk [Abstract]	'
Holding in aggregate market value permitted with written pre-authorization	10.00%
Minimum credit rating of any security purchased	'Baa3/BBB-
Allowable percentage holding in downgraded investments	2.00%
Percent of investment portfolio with a credit rating below the minimum required credit rating of Baa3/BBB-	1.30%
Total investment portfolio | Bank loans	'
Concentrations Of Credit Risk [Abstract]	'
Total investment portfolio, fair value	10.90%

Commitments_and_contingencies_1

Commitments and contingencies (Lloyd's syndicate) (Details)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013		Dec. 31, 2012		Sep. 30, 2013	Sep. 30, 2013
In Thousands, unless otherwise specified	USD ($)	USD ($)	Lloyd's Syndicate 1183	Lloyd's Syndicate 1183	Lloyd's Syndicate 1183	Talbot FAL Facility		Talbot FAL Facility		Talbot FAL Facility	Talbot FAL Facility
			USD ($)	GBP (£)	USD ($)	USD ($)		USD ($)		Lloyd's Syndicate 1183	Lloyd's Syndicate 1183
										Minimum	Maximum
										USD ($)	USD ($)
Components Of Required Capital [Abstract]	'	'	'	'	'	'		'		'	'
Loss contingency, loss level amount	'	'	'	'	'	'		'		$403,700	$428,700
Cash, investments and letters of credit amount	'	'	428,700	'	428,700	'		'		'	'
Credit facility, commitment	1,575,000	2,090,000	'	'	'	25,000	[1]	25,000	[1]	'	'
Funds at Lloyd's and Lloyd's Central Fund	'	'	'	'	'	'		'		'	'
Maximum premium levies assessable, percent	'	'	3.00%	3.00%	'	'		'		'	'
Estimated underwriting capacity	'	'	'	620,000	'	'		'		'	'
Exchange rate	'	'	'£1 equals $1.6192	'£1 equals $1.6192	'	'		'		'	'
Maximum premium levies assessable, amount	'	'	$30,117	'	'	'		'		'	'
[1]	Talbot operates in the Lloyd’s market ("Lloyds") through a corporate member, Talbot 2002 Underwriting Capital Ltd (“T02”), which is the sole participant in Syndicate 1183. Lloyd’s sets T02’s required capital annually based on Syndicate 1183’s business plan, rating environment, reserving environment together with input arising from Lloyd’s discussions with, inter alia, regulatory and rating agencies. Such capital, called Funds at Lloyd’s (“FAL”), comprises: cash, investments and undrawn letters of credit provided by various banks.

Commitments_and_contingencies_2

Commitments and contingencies (Aquiline commitment) (Details) (Aquiline Capital Partners II GP Offshore Ltd, USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Aquiline Capital Partners II GP Offshore Ltd	'
Related Party Transaction [Line Items]	'
Percentage of Assignor's interest assumed	100.00%
Total capital commitment	$50,000
Remaining capital commitment	$19,292

Related_party_transactions_Det

Related party transactions (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Aquiline Capital Partners LLC	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Shares owned by related party	4,946,643	'	4,946,643	'	'
Warrants to purchase shares	2,756,088	'	2,756,088	'	'
Group Ark Insurance Holdings Ltd	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Gross premiums written	$0	$6,167	$2,848	$7,582	'
Premiums receivable	603	'	603	'	251
Reinsurance premiums ceded	19	0	23	0	'
Loss reserves recoverable	4,420	3,694	4,420	3,694	'
Earned premium adjustments	718	5,019	2,147	5,751	'
Tiger Risk Partners LLC	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Brokerage expenses	'	58	'	2,418	'
Accounts payable and accrued expenses	'	'	'	'	964
Conning Inc	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Accounts payable and accrued expenses	179	'	179	'	201
Investment management fees	165	207	396	611	'
Aquiline Capital Partners II GP Offshore Ltd	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Accounts payable and accrued expenses	0	'	0	'	0
Percentage of Assignor's interest assumed	'	'	100.00%	'	'
Total capital commitment	'	'	50,000	'	'
Partnership fees incurred	505	674	625	2,560	'
Capital contributions	$6,185	$430	$13,089	$5,328	'

Earnings_per_share_Details

Earnings per share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic earnings per share	'	'	'	'
Net income	$229,063	$264,044	$419,503	$510,540
Net (income) loss attributable to noncontrolling interest	-45,694	-56,746	17,831	-11,386
Net income available to Validus	183,369	207,298	437,334	499,154
less: Dividends and distributions declared on outstanding warrants	-1,552	-1,663	-17,662	-5,121
Income available to common shareholders	181,817	205,635	419,672	494,033
Weighted average number of common shares outstanding	99,834,563	93,368,775	103,451,396	97,016,034
Basic earnings per share available to common shareholders	$1.82	$2.20	$4.06	$5.09
Diluted earnings per share	'	'	'	'
Net income	229,063	264,044	419,503	510,540
Net (income) loss attributable to noncontrolling interest	-45,694	-56,746	17,831	-11,386
Net income available to Validus	183,369	207,298	437,334	499,154
less: Dividends and distributions declared on outstanding warrants	0	0	-17,662	0
Income available to common shareholders	$183,369	$207,298	$419,672	$499,154
Weighted average number of common shares outstanding	99,834,563	93,368,775	103,451,396	97,016,034
Weighted average number of common shares outstanding, diluted	103,613,766	98,236,490	105,264,913	102,333,515
Diluted earnings per share available to common shareholders	$1.77	$2.11	$3.99	$4.88
Other details:	'	'	'	'
Anti-dilutive securities excluded from the calculation of diluted earnings per share	125,728	2,724	464,516	231,621
Warrants	'	'	'	'
Diluted earnings per share	'	'	'	'
Weighted average number diluted shares outstanding adjustment	2,606,669	3,248,788	0	3,116,298
Stock options	'	'	'	'
Diluted earnings per share	'	'	'	'
Weighted average number diluted shares outstanding adjustment	782,158	716,693	1,090,298	777,245
Unvested restricted shares	'	'	'	'
Diluted earnings per share	'	'	'	'
Weighted average number diluted shares outstanding adjustment	390,376	902,234	723,219	1,423,938

Segment_information_Details

Segment information (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
					subsidiaries
					segments
Segment Reporting Information [Line Items]	'		'		'		'		'
Number of wholly owned subsidiaries	'		'		2		'		'
Number of operating segments	'		'		3		'		'
Underwriting income	'		'		'		'		'
Gross premiums written	$356,760		$390,215		$2,163,833		$1,854,593		'
Reinsurance premiums ceded	-39,415		-45,743		-348,027		-271,847		'
Net premiums written	317,345		344,472		1,815,806		1,582,746		'
Change in unearned premiums	213,943		130,632		-205,999		-208,816		'
Net premiums earned	531,288		475,104		1,609,807		1,373,930		'
Underwriting deductions	'		'		'		'		'
Losses and loss expenses	177,965		155,455		587,780		541,136		'
Policy acquisition costs	94,900		98,623		275,663		252,884		'
General and administrative expenses	81,089		70,547		232,335		198,557		'
Share compensation expenses	10,527		7,345		19,483		19,583		'
Total underwriting deductions	364,481		331,970		1,115,261		1,012,160		'
Underwriting income (loss)	166,807		143,134		494,546		361,770		'
Net investment income	20,009		25,489		71,868		79,134		'
Other (loss) income	-2,806		7,324		4,297		22,209		'
Finance expenses	-27,132		-9,362		-89,408		-39,347		'
Operating income (loss) before taxes and income from operating affiliates	156,878		166,585		481,303		423,766		'
Tax (expense) benefit	-5		-1,343		220		-1,886		'
Income from operating affilates	1,463		6,235		8,779		13,194		'
Net operating income (loss)	158,336		171,477		490,302		435,074		'
Net realized gains on investments	-6,320		9,063		-1,190		22,749		'
Net unrealized gains (losses) on investments	69,967		86,345		-78,618		53,442		'
Income (loss) from investment affiliate	1,044		-160		4,274		-558		'
Foreign exchange (losses) gains	6,036		1,103		4,735		3,617		'
Transaction expenses	0		-3,784	[1]	0		-3,784	[1]	'
Net income	229,063		264,044		419,503		510,540		'
Net (income) loss attributable to noncontrolling interest	-45,694		-56,746		17,831		-11,386		'
Net income (loss) available (attributable) to Validus	183,369		207,298		437,334		499,154		'
Selected ratios:	'		'		'		'		'
Net premiums written / Gross premiums written	89.00%		88.30%		83.90%		85.30%		'
Losses and loss expenses	33.50%		32.70%		36.50%	[2]	39.40%	[2]	'
Policy acquisition costs	17.90%		20.80%		17.20%	[2]	18.40%	[2]	'
General and administrative expenses	17.20%	[2]	16.40%	[2]	15.60%	[2],[3]	15.90%	[2],[3]	'
Expense ratio	35.10%		37.20%		32.80%		34.30%		'
Combined ratio	68.60%		69.90%		69.30%		73.70%		'
Total assets	10,317,368		8,463,820		10,317,368		8,463,820		10,020,264
Validus Re Segment	'		'		'		'		'
Underwriting income	'		'		'		'		'
Gross premiums written	130,925		145,010		1,232,272		1,052,726		'
Reinsurance premiums ceded	-13,006		-10,426		-226,292		-137,504		'
Net premiums written	117,919		134,584		1,005,980		915,222		'
Change in unearned premiums	157,873		107,728		-122,303		-177,215		'
Net premiums earned	275,792		242,312		883,677		738,007		'
Underwriting deductions	'		'		'		'		'
Losses and loss expenses	62,250		66,890		319,298		244,286		'
Policy acquisition costs	47,662		37,785		142,195		113,659		'
General and administrative expenses	19,785		16,938		69,649		48,332		'
Share compensation expenses	2,479		2,076		5,421		5,914		'
Total underwriting deductions	132,176		123,689		536,563		412,191		'
Underwriting income (loss)	143,616		118,623		347,114		325,816		'
Net investment income	15,628		19,644		61,770		64,915		'
Other (loss) income	-1,892		1,543		11,237		4,229		'
Finance expenses	-3,640		-789		-12,133		-6,628		'
Operating income (loss) before taxes and income from operating affiliates	153,712		139,021		407,988		388,332		'
Tax (expense) benefit	143		-2		1,755		-11		'
Income from operating affilates	0		0		0		0		'
Net operating income (loss)	153,855		139,019		409,743		388,321		'
Net realized gains on investments	-10,137		6,643		-5,790		17,708		'
Net unrealized gains (losses) on investments	23,144		19,232		-36,883		35,400		'
Income (loss) from investment affiliate	1,044		-160		4,274		-558		'
Foreign exchange (losses) gains	2,168		8		7,448		2,461		'
Net income	170,074		164,742		378,792		443,332		'
Net (income) loss attributable to noncontrolling interest	0		0		0		0		'
Net income (loss) available (attributable) to Validus	170,074		164,742		378,792		443,332		'
Selected ratios:	'		'		'		'		'
Net premiums written / Gross premiums written	90.10%		92.80%		81.60%		86.90%		'
Losses and loss expenses	22.60%		27.60%		36.10%	[2]	33.10%	[2]	'
Policy acquisition costs	17.30%		15.60%		16.10%	[2]	15.40%	[2]	'
General and administrative expenses	8.10%	[2]	7.80%	[2]	8.50%	[2],[3]	7.40%	[2],[3]	'
Expense ratio	25.40%		23.40%		24.60%		22.80%		'
Combined ratio	48.00%		51.00%		60.70%		55.90%		'
Total assets	5,854,354		4,729,344		5,854,354		4,729,344		'
AlphaCat Segment	'		'		'		'		'
Underwriting income	'		'		'		'		'
Gross premiums written	3,481		2,934		146,757		21,607		'
Reinsurance premiums ceded	-525		0		-525		0		'
Net premiums written	2,956		2,934		146,232		21,607		'
Change in unearned premiums	34,210		2,591		-46,459		-9,832		'
Net premiums earned	37,166		5,525		99,773		11,775		'
Underwriting deductions	'		'		'		'		'
Losses and loss expenses	15,615		0		16,928		0		'
Policy acquisition costs	3,787		547		10,011		1,185		'
General and administrative expenses	5,728		2,087		13,757		5,521		'
Share compensation expenses	152		84		314		195		'
Total underwriting deductions	25,282		2,718		41,010		6,901		'
Underwriting income (loss)	11,884		2,807		58,763		4,874		'
Net investment income	967		1,193		2,821		2,672		'
Other (loss) income	3,791		7,674		17,439		22,237		'
Finance expenses	-11,895		-56		-46,429		-495		'
Operating income (loss) before taxes and income from operating affiliates	4,747		11,618		32,594		29,288		'
Tax (expense) benefit	0		0		0		0		'
Income from operating affilates	1,463		6,235		8,779		13,194		'
Net operating income (loss)	6,210		17,853		41,373		42,482		'
Net realized gains on investments	4,084		300		4,084		216		'
Net unrealized gains (losses) on investments	44,145		62,432		-31,029		12,316		'
Income (loss) from investment affiliate	0		0		0		0		'
Foreign exchange (losses) gains	388		30		-663		47		'
Net income	54,827		80,615		13,765		55,061		'
Net (income) loss attributable to noncontrolling interest	-45,694		-56,746		17,831		-11,386		'
Net income (loss) available (attributable) to Validus	9,133		23,869		31,596		43,675		'
Selected ratios:	'		'		'		'		'
Net premiums written / Gross premiums written	84.90%		100.00%		99.60%		100.00%		'
Losses and loss expenses	42.00%		0.00%		17.00%	[2]	0.00%	[2]	'
Policy acquisition costs	10.20%		9.90%		10.00%	[2]	10.10%	[2]	'
General and administrative expenses	15.80%	[2]	39.30%	[2]	14.10%	[2],[3]	48.50%	[2],[3]	'
Expense ratio	26.00%		49.20%		24.10%		58.60%		'
Combined ratio	68.00%		49.20%		41.10%		58.60%		'
Total assets	1,446,941		768,612		1,446,941		768,612		'
Talbot Segment	'		'		'		'		'
Underwriting income	'		'		'		'		'
Gross premiums written	246,468		260,755		855,516		837,536		'
Reinsurance premiums ceded	-49,998		-53,801		-191,922		-191,619		'
Net premiums written	196,470		206,954		663,594		645,917		'
Change in unearned premiums	21,860		20,313		-37,237		-21,769		'
Net premiums earned	218,330		227,267		626,357		624,148		'
Underwriting deductions	'		'		'		'		'
Losses and loss expenses	100,100		88,565		251,554		296,850		'
Policy acquisition costs	44,899		61,640		127,092		142,181		'
General and administrative expenses	37,402		36,605		100,506		100,910		'
Share compensation expenses	2,992		2,200		6,754		5,347		'
Total underwriting deductions	185,393		189,010		485,906		545,288		'
Underwriting income (loss)	32,937		38,257		140,451		78,860		'
Net investment income	4,395		5,260		13,496		16,475		'
Other (loss) income	73		680		564		2,033		'
Finance expenses	-107		-73		-256		-224		'
Operating income (loss) before taxes and income from operating affiliates	37,298		44,124		154,255		97,144		'
Tax (expense) benefit	-513		-11		-1,184		-562		'
Income from operating affilates	0		0		0		0		'
Net operating income (loss)	36,785		44,113		153,071		96,582		'
Net realized gains on investments	-267		2,120		516		4,825		'
Net unrealized gains (losses) on investments	2,678		4,681		-10,706		5,726		'
Income (loss) from investment affiliate	0		0		0		0		'
Foreign exchange (losses) gains	4,238		1,146		-1,877		1,334		'
Net income	43,434		52,060		141,004		108,467		'
Net (income) loss attributable to noncontrolling interest	0		0		0		0		'
Net income (loss) available (attributable) to Validus	43,434		52,060		141,004		108,467		'
Selected ratios:	'		'		'		'		'
Net premiums written / Gross premiums written	79.70%		79.40%		77.60%		77.10%		'
Losses and loss expenses	45.80%		39.00%		40.20%	[2]	47.60%	[2]	'
Policy acquisition costs	20.60%		27.10%		20.30%	[2]	22.80%	[2]	'
General and administrative expenses	18.50%	[2]	17.10%	[2]	17.10%	[2],[3]	17.00%	[2],[3]	'
Expense ratio	39.10%		44.20%		37.40%		39.80%		'
Combined ratio	84.90%		83.20%		77.60%		87.40%		'
Total assets	2,892,477		2,931,174		2,892,477		2,931,174		'
Corporate, Non-Segment	'		'		'		'		'
Underwriting income	'		'		'		'		'
Gross premiums written	-24,114		-18,484		-70,712		-57,276		'
Reinsurance premiums ceded	24,114		18,484		70,712		57,276		'
Net premiums written	0		0		0		0		'
Change in unearned premiums	0		0		0		0		'
Net premiums earned	0		0		0		0		'
Underwriting deductions	'		'		'		'		'
Losses and loss expenses	0		0		0		0		'
Policy acquisition costs	-1,448		-1,349		-3,635		-4,141		'
General and administrative expenses	18,174		14,917		48,423		43,794		'
Share compensation expenses	4,904		2,985		6,994		8,127		'
Total underwriting deductions	21,630		16,553		51,782		47,780		'
Underwriting income (loss)	-21,630		-16,553		-51,782		-47,780		'
Net investment income	-981		-608		-6,219		-4,928		'
Other (loss) income	-4,778		-2,573		-24,943		-6,290		'
Finance expenses	-11,490		-8,444		-30,590		-32,000		'
Operating income (loss) before taxes and income from operating affiliates	-38,879		-28,178		-113,534		-90,998		'
Tax (expense) benefit	365		-1,330		-351		-1,313		'
Income from operating affilates	0		0		0		0		'
Net operating income (loss)	-38,514		-29,508		-113,885		-92,311		'
Net realized gains on investments	0		0		0		0		'
Net unrealized gains (losses) on investments	0		0		0		0		'
Income (loss) from investment affiliate	0		0		0		0		'
Foreign exchange (losses) gains	-758		-81		-173		-225		'
Transaction expenses	'		-3,784	[1]	'		-3,784	[1]	'
Net income	-39,272		-33,373		-114,058		-96,320		'
Net (income) loss attributable to noncontrolling interest	0		0		0		0		'
Net income (loss) available (attributable) to Validus	-39,272		-33,373		-114,058		-96,320		'
Selected ratios:	'		'		'		'		'
Total assets	$123,596		$34,690		$123,596		$34,690		'
[1]	The transaction expenses relate to costs incurred in connection with the acquisition of Flagstone Reinsurance Holdings, S.A.
[2]	Ratios are based on net premiums earned.
[3]	The general and administrative expense ratio includes share compensation expenses.

Segment_information_Segment_ge

Segment information (Segment geographic) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	$356,760		$390,215		$2,163,833		$1,854,593
Percent of gross premiums written	100.00%		100.00%		100.00%		100.00%
United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	61,632		74,871		588,711		418,183
Percent of gross premiums written	17.30%		19.20%		27.20%		22.50%
Worldwide excluding United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	47,586	[1]	33,169	[1]	184,780	[1]	156,722	[1]
Percent of gross premiums written	13.30%	[1]	8.50%	[1]	8.40%	[1]	8.50%	[1]
Australia and New Zealand	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-6,780	[1]	10,091	[1]	30,795		46,768
Percent of gross premiums written	-1.90%	[1]	2.60%	[1]	1.40%		2.50%
Europe	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	13,421		20,441		105,131		105,706
Percent of gross premiums written	3.80%		5.20%		4.90%		5.70%
Latin America and Caribbean	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	40,633		37,413		122,693		113,151
Percent of gross premiums written	11.40%		9.60%		5.70%		6.10%
Japan	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-1,688		2,561		46,887		37,193
Percent of gross premiums written	-0.50%		0.70%		2.20%		2.00%
Canada	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	3,978		3,698		12,775		11,485
Percent of gross premiums written	1.10%		0.90%		0.60%		0.60%
Rest of the world	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	25,978	[2]	34,742	[2]	88,314	[2]	95,760	[2]
Percent of gross premiums written	7.30%	[2]	8.90%	[2]	4.10%	[2]	5.20%	[2]
Sub-total, non United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	123,128		142,115		591,375		566,785
Percent of gross premiums written	34.50%		36.40%		27.30%		30.60%
Worldwide including United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	46,217	[1]	33,702	[1]	309,225	[1]	220,984	[1]
Percent of gross premiums written	13.00%	[1]	8.60%	[1]	14.30%	[1]	11.90%	[1]
Other location non-specific	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	125,783		139,527		674,522	[3]	648,641	[3]
Percent of gross premiums written	35.30%		35.80%		31.20%	[3]	35.00%	[3]
Validus Re Segment	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	130,925		145,010		1,232,272		1,052,726
Validus Re Segment | United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	39,618		53,138		470,745		347,492
Validus Re Segment | Worldwide excluding United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	16,973		7,085		69,482	[1]	51,289	[1]
Validus Re Segment | Australia and New Zealand	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-9,482		4,887		21,116		37,474
Validus Re Segment | Europe	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	4,252		10,251		'		67,206
Gross premiums written	'		'		64,986		'
Validus Re Segment | Latin America and Caribbean	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	5,902		3,299		5,885		8,456
Validus Re Segment | Japan	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-2,637		781		41,939		31,597
Validus Re Segment | Canada	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	1,469		260		4,503		2,753
Validus Re Segment | Rest of the world	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	5,641		6,303		29,211	[2]	23,857	[2]
Validus Re Segment | Sub-total, non United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	22,118		32,866		237,122		222,632
Validus Re Segment | Worldwide including United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	29,611		17,375		180,621	[1]	166,550	[1]
Validus Re Segment | Other location non-specific	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	39,578		41,631		343,784	[3]	316,052	[3]
AlphaCat Segment	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	3,481		2,934		146,757		21,607
AlphaCat Segment | United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	2,546		2,211		50,935		12,643
AlphaCat Segment | Worldwide excluding United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	0	[1]	0	[1]	14,801	[1]	278	[1]
AlphaCat Segment | Australia and New Zealand	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	33	[1]	217	[1]	2,216		217
AlphaCat Segment | Europe	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	377		512		2,514		1,332
AlphaCat Segment | Latin America and Caribbean	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	0		0		0		0
AlphaCat Segment | Japan	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	0		0		653		0
AlphaCat Segment | Canada	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	500		0		818		0
AlphaCat Segment | Rest of the world	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	0	[2]	0	[2]	0	[2]	0	[2]
AlphaCat Segment | Sub-total, non United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	910		729		21,002		1,827
AlphaCat Segment | Worldwide including United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	25	[1]	-6	[1]	74,820	[1]	7,137	[1]
AlphaCat Segment | Other location non-specific	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	0		0		0	[3]	0	[3]
Talbot Segment	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	246,468		260,755		855,516		837,536
Talbot Segment | United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	21,573		21,004		77,630		62,812
Talbot Segment | Worldwide excluding United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	34,751	[1]	28,113	[1]	109,562	[1]	115,836	[1]
Talbot Segment | Australia and New Zealand	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	2,905	[1]	5,356	[1]	7,930		9,798
Talbot Segment | Europe	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	9,778		10,426		41,523		39,871
Talbot Segment | Latin America and Caribbean	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	38,084		36,735		124,120		112,329
Talbot Segment | Japan	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	1,066		1,916		5,258		6,003
Talbot Segment | Canada	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	2,749		3,696		8,790		9,366
Talbot Segment | Rest of the world	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	22,167	[2]	30,572	[2]	62,803	[2]	74,036	[2]
Talbot Segment | Sub-total, non United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	111,500		116,814		359,986		367,239
Talbot Segment | Worldwide including United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	18,246	[1]	17,571	[1]	63,998	[1]	50,737	[1]
Talbot Segment | Other location non-specific	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	95,149		105,366		353,902	[3]	356,748	[3]
Corporate, Non-Segment	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-24,114		-18,484		-70,712		-57,276
Eliminations | United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-2,105		-1,482		-10,599		-4,764
Eliminations | Worldwide excluding United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-4,138	[1]	-2,029	[1]	-9,065	[1]	-10,681	[1]
Eliminations | Australia and New Zealand	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-236	[1]	-369	[1]	-467		-721
Eliminations | Europe	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-986		-748		-3,892		-2,703
Eliminations | Latin America and Caribbean	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-3,353		-2,621		-7,312		-7,634
Eliminations | Japan	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-117		-136		-963		-407
Eliminations | Canada	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-740		-258		-1,336		-634
Eliminations | Rest of the world	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-1,830	[2]	-2,133	[2]	-3,700	[2]	-2,133	[2]
Eliminations | Sub-total, non United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-11,400		-8,294		-26,735		-24,913
Eliminations | Worldwide including United States	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	-1,665	[1]	-1,238	[1]	-10,214	[1]	-3,440	[1]
Eliminations | Other location non-specific	'		'		'		'
Gross premiums written allocated to the territory of coverage exposure	'		'		'		'
Gross premiums written	($8,944)		($7,470)		($23,164)	[3]	($24,159)	[3]
[1]	Represents risks in two or more geographic zones.
[2]	Represents risks in one geographic zone.
[3]	The Other location non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable such as marine and aerospace risks and can span multiple geographic areas and are not fixed locations in some instances.

Subsequent_events_Details

Subsequent events (Details) (USD $)

0 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

In Thousands, except Per Share data, unless otherwise specified

Feb. 06, 2013

Sep. 30, 2013

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Oct. 30, 2013

Oct. 31, 2013

Oct. 30, 2013

Common shares

Common shares

Common shares

Common shares

Common share equivalents

Common share equivalents

Common share equivalents

Subsequent Event

Subsequent Event

Subsequent Event

Common shares

Common shares

Common share equivalents

Subsequent Event [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash dividends declared per share

'

$0.30

$0.25

$0.25

$0.25

$2.90

$0.75

$0.30

$0.30

$0.30

'

$0.30

$0.30

$0.30

$0.30

'

$0.30

Stock Repurchase Program, Authorized Amount

$500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$500,000

'

Share Repurchase Program Cumulative Aggregrate Purchase Value

$1,206,845

'

'

'

'

'

'

'

'

'

$1,564,029

'

'

'

'

$1,567,380

'