Schedule II - Condensed financial information of registrant (Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues
Net investment income	$ 38,153	$ 43,514	$ 39,257	$ 29,461	$ 31,612	$ 31,572	$ 33,611	$ 31,029	$ 150,385	$ 127,824	$ 100,086
Change in net unrealized gains (losses) on managed investments (a)	(67,460)	5,459	31,428	47,444	(34,862)	3,916	(34,676)	33,227	16,871	(32,395)	(2,842)
Foreign exchange gains	(901)	(766)	6,286	6,245	797	(2,592)	(2,671)	(4,265)	10,864	(8,731)	(12,181)
Total revenues	522,145	616,222	653,653	651,134	539,203	590,728	571,580	643,766	2,443,154	2,345,277	2,102,675
Expenses
General and administrative expenses	77,955	82,443	89,688	86,208	98,563	96,886	84,025	84,235	336,294	363,709	329,362
Share compensation expenses	10,442	10,501	10,727	11,237	10,062	9,983	9,242	9,054	42,907	38,341	33,073
Finance expenses	14,630	14,521	14,166	15,203	16,581	18,512	18,682	20,967	58,520	74,742	68,324
Net income available to Validus	9,970	92,096	94,963	166,810	69,042	66,650	65,790	173,411	363,839	374,893	479,963
Dividends on preferred shares	(2,203)	(2,252)	0	0	0	0	0	0	(4,455)	0	0
Net income available to Validus common shareholders	$ 7,767	$ 89,844	$ 94,963	$ 166,810	$ 69,042	$ 66,650	$ 65,790	$ 173,411	359,384	374,893	479,963
Change in foreign currency translation adjustments									(10,440)	(3,716)	(7,501)
Change in minimum pension liability, net of tax									(484)	544	(210)
Change in fair value of cash flow hedge									277	(841)	(228)
Other comprehensive loss									(10,647)	(4,013)	(7,939)
Comprehensive income (loss) available (attributable) to Validus									353,192	370,880	472,024
Parent Company
Revenues
Net investment income									1,195	317	14
Net realized gains on investments									8,020	0	0
Change in net unrealized gains (losses) on managed investments (a)									(276)	(395)	0
Foreign exchange gains									1,932	715	648
Total revenues									10,871	637	662
Expenses
General and administrative expenses									72,235	74,015	86,108
Share compensation expenses									6,832	7,261	6,424
Finance expenses									47,108	47,722	47,689
Total expenses									126,175	128,998	140,221
(Loss) before equity in net earnings of subsidiaries									(115,304)	(128,361)	(139,559)
Equity in net earnings of subsidiaries									479,143	503,254	619,522
Net income available to Validus									363,839	374,893	479,963
Dividends on preferred shares									(4,455)	0	0
Net income available to Validus common shareholders									359,384	374,893	479,963
Change in foreign currency translation adjustments									(10,440)	(3,716)	(7,501)
Change in minimum pension liability, net of tax									(484)	544	(210)
Change in fair value of cash flow hedge									277	(841)	(228)
Other comprehensive loss									(10,647)	(4,013)	(7,939)
Comprehensive income (loss) available (attributable) to Validus									$ 353,192	$ 370,880	$ 472,024