Segment information (Gross premiums written by geographic location and segment) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		$ 764,042	$ 726,168	$ 1,936,833	$ 1,845,392
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		$ 292,114	$ 313,968	$ 701,830	$ 749,678
Percent of gross premiums written		38.20%	43.30%	36.20%	40.70%
Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	$ 53,363	$ 44,795	$ 134,667	$ 119,534
Percent of gross premiums written	[1]	7.00%	6.20%	7.00%	6.50%
Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		$ 4,877	$ 3,465	$ 16,060	$ 15,054
Percent of gross premiums written		0.60%	0.50%	0.80%	0.80%
Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		$ 10,193	$ 27,855	$ 49,048	$ 66,423
Percent of gross premiums written		1.30%	3.80%	2.50%	3.60%
Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		$ 31,078	$ 32,458	$ 65,441	$ 60,504
Percent of gross premiums written		4.10%	4.50%	3.40%	3.30%
Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		$ 44,732	$ 42,269	$ 47,697	$ 44,394
Percent of gross premiums written		5.90%	5.80%	2.50%	2.40%
Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		$ 4,478	$ 3,142	$ 7,195	$ 7,143
Percent of gross premiums written		0.60%	0.40%	0.40%	0.40%
Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[2]	$ 32,608	$ 27,714	$ 74,895	$ 67,126
Percent of gross premiums written	[2]	4.30%	3.80%	3.90%	3.60%
Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		$ 181,329	$ 181,698	$ 395,003	$ 380,178
Percent of gross premiums written		23.80%	25.00%	20.50%	20.60%
Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	$ 121,773	$ 101,060	$ 368,543	$ 273,954
Percent of gross premiums written	[1]	15.90%	13.90%	19.00%	14.80%
Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[3]	$ 168,826	$ 129,442	$ 471,457	$ 441,582
Percent of gross premiums written	[3]	22.10%	17.80%	24.30%	23.90%
Operating Segments | Validus Re
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		$ 285,810	$ 297,420	$ 977,478	$ 1,009,113
Operating Segments | Validus Re | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		129,087	171,006	424,481	510,020
Operating Segments | Validus Re | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	16,975	12,322	47,239	47,288
Operating Segments | Validus Re | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		1,926	1,643	6,849	11,507
Operating Segments | Validus Re | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		3,267	16,282	25,734	41,017
Operating Segments | Validus Re | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		5,992	7,684	19,574	16,932
Operating Segments | Validus Re | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		39,053	37,800	39,925	39,184
Operating Segments | Validus Re | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		1,821	597	3,497	2,782
Operating Segments | Validus Re | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[2]	3,259	3,026	19,947	21,680
Operating Segments | Validus Re | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		72,293	79,354	162,765	180,390
Operating Segments | Validus Re | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	35,561	37,967	147,338	122,811
Operating Segments | Validus Re | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[3]	48,869	9,093	242,894	195,892
Operating Segments | Talbot Segment
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		296,067	293,046	562,384	563,123
Operating Segments | Talbot Segment | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		39,135	40,036	65,245	68,094
Operating Segments | Talbot Segment | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	30,028	30,231	65,532	65,173
Operating Segments | Talbot Segment | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		2,063	1,173	4,375	3,049
Operating Segments | Talbot Segment | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		6,855	10,584	20,716	23,798
Operating Segments | Talbot Segment | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		27,597	28,693	51,404	51,385
Operating Segments | Talbot Segment | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		3,965	2,843	4,582	3,597
Operating Segments | Talbot Segment | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		2,470	2,299	3,562	3,997
Operating Segments | Talbot Segment | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[2]	29,806	24,982	57,290	47,988
Operating Segments | Talbot Segment | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		102,784	100,805	207,461	198,987
Operating Segments | Talbot Segment | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	34,198	32,704	62,652	54,498
Operating Segments | Talbot Segment | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[3]	119,950	119,501	227,026	241,544
Operating Segments | Western World
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		86,971	79,554	150,930	136,501
Operating Segments | Western World | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		86,971	79,554	150,930	136,501
Operating Segments | Western World | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	0	0	0	0
Operating Segments | Western World | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		0	0	0	0
Operating Segments | Western World | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		0	0	0	0
Operating Segments | Western World | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		0	0	0	0
Operating Segments | Western World | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		0	0	0	0
Operating Segments | Western World | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		0	0	0	0
Operating Segments | Western World | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[2]	0	0	0	0
Operating Segments | Western World | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		0	0	0	0
Operating Segments | Western World | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	0	0	0	0
Operating Segments | Western World | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[3]	0	0	0	0
Operating Segments | AlphaCat
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[4]	98,905	62,795	266,253	164,600
Operating Segments | AlphaCat | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		37,338	23,800	62,729	36,945
Operating Segments | AlphaCat | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	6,496	2,173	22,507	8,006
Operating Segments | AlphaCat | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		867	624	4,949	624
Operating Segments | AlphaCat | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		(145)	1,073	3,306	2,512
Operating Segments | AlphaCat | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		0	0	0	0
Operating Segments | AlphaCat | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		1,721	1,671	3,221	1,671
Operating Segments | AlphaCat | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		223	294	223	488
Operating Segments | AlphaCat | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[2]	0	0	0	0
Operating Segments | AlphaCat | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		9,162	5,835	34,206	13,301
Operating Segments | AlphaCat | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	52,394	32,410	167,767	110,304
Operating Segments | AlphaCat | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[3]	11	750	1,551	4,050
Eliminations
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		(3,711)	(6,647)	(20,212)	(27,945)
Eliminations | United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		(417)	(428)	(1,555)	(1,882)
Eliminations | Worldwide excluding United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	(136)	69	(611)	(933)
Eliminations | Australia and New Zealand
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		21	25	(113)	(126)
Eliminations | Europe
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		216	(84)	(708)	(904)
Eliminations | Latin America and Caribbean
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		(2,511)	(3,919)	(5,537)	(7,813)
Eliminations | Japan
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		(7)	(45)	(31)	(58)
Eliminations | Canada
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		(36)	(48)	(87)	(124)
Eliminations | Rest of the world
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[2]	(457)	(294)	(2,342)	(2,542)
Eliminations | Sub-total, non United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written		(2,910)	(4,296)	(9,429)	(12,500)
Eliminations | Worldwide including United States
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[1]	(380)	(2,021)	(9,214)	(13,659)
Eliminations | Other location non-specific
Gross premiums written allocated to the territory of coverage exposure
Gross premiums written	[3]	$ (4)	$ 98	$ (14)	$ 96

[1] Represents risks in two or more geographic zones.

[2] Represents risks in one geographic zone.

[3] The Other locations non-specific category refers to business for which an analysis of exposure by geographic zone is not applicable since these exposures can span multiple geographic areas and, in some instances, are not fixed locations.

[4] The results of AlphaCat are presented on an asset manager basis, which is non-GAAP. A reconciliation of segmental income to net income available to Validus is included in the tables below.