Segment information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Underwriting income
Gross premiums written	$ 605,387	$ 516,861	$ 1,455,283	$ 1,387,795
Reinsurance premiums ceded	(132,346)	(67,726)	(242,166)	(158,465)
Net premiums written	473,041	449,135	1,213,117	1,229,330
Change in unearned premiums	(47,401)	(11,191)	(357,944)	(333,692)
Net premiums earned	425,640	437,944	855,173	895,638
Underwriting deductions
Losses and loss expenses	207,307	194,894	683,505	673,425
Policy acquisition costs	78,230	74,126	155,526	150,302
General and administrative expenses	60,841	52,379	109,318	105,948
Share compensation expenses	7,628	6,846	19,677	13,422
Total underwriting deductions	354,006	328,245	968,026	943,097
Underwriting income (loss)	71,634	109,699	(112,853)	(47,459)
Net investment income	26,494	34,809	56,469	69,108
Other income	595	2,697	2,201	3,585
Finance expenses	(16,361)	(13,218)	(30,362)	(28,369)
Operating income (loss) before taxes	82,362	133,987	(84,545)	(3,135)
Tax benefit (expense)	29	(4,187)	1,488	(3,490)
Net operating income (loss)	82,391	129,800	(83,057)	(6,625)
Net realized gains on investments	11,552	12,441	17,931	23,839
Net unrealized gains on investments	18,526	41,640	5,698	57,053
Foreign exchange (losses) gains	(1,991)	(4,099)	(2,458)	(12,863)
Net income (loss)	110,478	179,782	(61,886)	61,404
Net income attributable to noncontrolling interest	(594)		(594)
Net income (loss) available (attributable) to Validus	109,884	179,782	(62,480)	61,404
Selected ratios:
Net premiums written / Gross premiums written	78.10%	86.90%	83.40%	88.60%
Losses and loss expenses	48.70%	44.50%	79.90%	75.20%
Policy acquisition costs	18.40%	16.90%	18.20%	16.80%
General and administrative expenses	16.10%	13.50%	15.10%	13.30%
Expense ratio	34.50%	30.40%	33.30%	30.10%
Combined ratio	83.20%	74.90%	113.20%	105.30%
Total assets	8,259,788	7,614,623	8,259,788	7,614,623	7,060,878
Validus Re [Member]
Underwriting income
Gross premiums written	341,651	284,328	952,889	924,623
Reinsurance premiums ceded	(98,218)	(41,175)	(145,023)	(54,285)
Net premiums written	243,433	243,153	807,866	870,338
Change in unearned premiums	(10,755)	18,888	(322,879)	(324,376)
Net premiums earned	232,678	262,041	484,987	545,962
Underwriting deductions
Losses and loss expenses	94,035	123,793	404,579	472,713
Policy acquisition costs	35,769	37,979	75,835	81,482
General and administrative expenses	15,458	10,983	26,115	27,295
Share compensation expenses	1,823	1,749	4,928	3,378
Total underwriting deductions	147,085	174,504	511,457	584,868
Underwriting income (loss)	85,593	87,537	(26,470)	(38,906)
Net investment income	22,389	29,914	48,040	59,159
Other income	854	1,477	2,287	2,555
Finance expenses	(4,502)	(1,107)	(6,215)	(2,400)
Operating income (loss) before taxes	104,334	117,821	17,642	20,408
Tax benefit (expense)	(4)	(94)	(6)	(185)
Net operating income (loss)	104,330	117,727	17,636	20,223
Net realized gains on investments	9,552	10,363	13,471	20,142
Net unrealized gains on investments	14,557	35,697	6,042	47,892
Foreign exchange (losses) gains	(5,337)	(843)	(9,697)	(5,982)
Net income (loss)	123,102	162,944	27,452	82,275
Net income attributable to noncontrolling interest	(594)		(594)
Net income (loss) available (attributable) to Validus	122,508	162,944	26,858	82,275
Selected ratios:
Net premiums written / Gross premiums written	71.30%	85.50%	84.80%	94.10%
Losses and loss expenses	40.40%	47.20%	83.40%	86.60%
Policy acquisition costs	15.40%	14.50%	15.60%	14.90%
General and administrative expenses	7.40%	4.90%	6.40%	5.60%
Expense ratio	22.80%	19.40%	22.00%	20.50%
Combined ratio	63.20%	66.60%	105.40%	107.10%
Total assets	5,411,663	5,057,693	5,411,663	5,057,693
Talbot [Member]
Underwriting income
Gross premiums written	276,886	253,710	539,943	524,251
Reinsurance premiums ceded	(47,278)	(47,728)	(134,692)	(165,259)
Net premiums written	229,608	205,982	405,251	358,992
Change in unearned premiums	(36,646)	(30,079)	(35,065)	(9,316)
Net premiums earned	192,962	175,903	370,186	349,676
Underwriting deductions
Losses and loss expenses	113,272	71,101	278,926	200,712
Policy acquisition costs	42,307	38,647	79,523	73,592
General and administrative expenses	34,718	24,960	63,440	50,508
Share compensation expenses	2,026	1,468	4,745	3,027
Total underwriting deductions	192,323	136,176	426,634	327,839
Underwriting income (loss)	639	39,727	(56,448)	21,837
Net investment income	6,372	7,251	12,962	14,571
Other income	1,967	3,084	4,984	5,059
Finance expenses		105	(63)	(3,140)
Operating income (loss) before taxes	8,978	50,167	(38,565)	38,327
Tax benefit (expense)	(208)	(4,094)	1,585	(3,299)
Net operating income (loss)	8,770	46,073	(36,980)	35,028
Net realized gains on investments	2,000	2,078	4,460	3,697
Net unrealized gains on investments	3,969	5,943	(344)	9,161
Foreign exchange (losses) gains	3,410	(3,243)	7,311	(6,842)
Net income (loss)	18,149	50,851	(25,553)	41,044
Net income (loss) available (attributable) to Validus	18,149	50,851	(25,553)	41,044
Selected ratios:
Net premiums written / Gross premiums written	82.90%	81.20%	75.10%	68.50%
Losses and loss expenses	58.70%	40.40%	75.30%	57.40%
Policy acquisition costs	21.90%	22.00%	21.50%	21.00%
General and administrative expenses	19.00%	15.00%	18.40%	15.30%
Expense ratio	40.90%	37.00%	39.90%	36.30%
Combined ratio	99.60%	77.40%	115.20%	93.70%
Total assets	2,759,850	2,507,586	2,759,850	2,507,586
Corporate & Eliminations [Member]
Underwriting income
Gross premiums written	(13,150)	(21,177)	(37,549)	(61,079)
Reinsurance premiums ceded	13,150	21,177	37,549	61,079
Underwriting deductions
Policy acquisition costs	154	(2,500)	168	(4,772)
General and administrative expenses	10,665	16,436	19,763	28,145
Share compensation expenses	3,779	3,629	10,004	7,017
Total underwriting deductions	14,598	17,565	29,935	30,390
Underwriting income (loss)	(14,598)	(17,565)	(29,935)	(30,390)
Net investment income	(2,267)	(2,356)	(4,533)	(4,622)
Other income	(2,226)	(1,864)	(5,070)	(4,029)
Finance expenses	(11,859)	(12,216)	(24,084)	(22,829)
Operating income (loss) before taxes	(30,950)	(34,001)	(63,622)	(61,870)
Tax benefit (expense)	241	1	(91)	(6)
Net operating income (loss)	(30,709)	(34,000)	(63,713)	(61,876)
Foreign exchange (losses) gains	(64)	(13)	(72)	(39)
Net income (loss)	(30,773)	(34,013)	(63,785)	(61,915)
Net income (loss) available (attributable) to Validus	(30,773)	(34,013)	(63,785)	(61,915)
Selected ratios:
Total assets	$ 88,275	$ 49,344	$ 88,275	$ 49,344