Segment information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 subsidiaries		Mar. 31, 2013		Dec. 31, 2013
Segment Reporting Information [Line Items]
Number of wholly owned subsidiaries	3
Underwriting income
Gross premiums written	$ 1,011,991		$ 1,104,760
Reinsurance premiums ceded	(194,908)		(187,216)
Net premiums written	817,083		917,544
Change in unearned premiums	(334,126)		(386,483)
Net premiums earned	482,957		531,061
Underwriting deductions
Losses and loss expenses	162,671		144,771
Policy acquisition costs	85,649		93,611
General and administrative expenses	74,445		80,279
Share compensation expenses	7,147		2,318
Total underwriting deductions	329,912		320,979
Underwriting income (loss)	153,045		210,082
Net investment income	23,362		25,649
Other income	13,830		2,685
Finance expenses	(15,900)		(14,369)
Operating income (loss) before taxes and income from operating affiliates	174,337		224,047
Tax benefit	40		318
Income from operating affilates	4,927		3,523
(Income) attributable to operating affiliate investors	(31,710)		(10,077)
Net operating income (loss)	147,594		217,811
Net realized gains on investments	3,740		1,721
Change in net unrealized gains (losses) on investments	55,693		(7,237)
Income from investment affiliate	5,348		1,477
Foreign exchange (losses) gains	(6,478)		6,922
Net income	205,897		220,694
Net (income) loss attributable to noncontrolling interest	(43,509)		2,549
Net income (loss) available (attributable) to Validus	162,388		223,243
Selected ratios:
Net premiums written / Gross premiums written	80.70%	[1]	83.10%	[1]
Losses and loss expenses	33.70%	[1]	27.30%	[1]
Policy acquisition costs	17.70%	[1]	17.60%	[1]
General and administrative expenses	16.90%	[1],[2]	15.60%	[1],[2]
Expense ratio	34.60%	[1]	33.20%	[1]
Combined ratio	68.30%	[1]	60.50%	[1]
Total assets	10,256,089		10,564,400		9,846,432
Operating Segments [Member] | Validus Re Segment
Underwriting income
Gross premiums written	678,986		747,963
Reinsurance premiums ceded	(142,640)		(125,728)
Net premiums written	536,346		622,235
Change in unearned premiums	(297,960)		(319,101)
Net premiums earned	238,386		303,134
Underwriting deductions
Losses and loss expenses	68,155		73,402
Policy acquisition costs	39,245		51,744
General and administrative expenses	18,195		29,441
Share compensation expenses	2,208		1,413
Total underwriting deductions	127,803		156,000
Underwriting income (loss)	110,583		147,134
Net investment income	18,765		23,193
Other income	6,770		13,490
Finance expenses	(3,839)		(3,252)
Operating income (loss) before taxes and income from operating affiliates	132,279		180,565
Tax benefit	578		1,757
Income from operating affilates	0		0
(Income) attributable to operating affiliate investors	0		0
Net operating income (loss)	132,857		182,322
Net realized gains on investments	2,446		1,593
Change in net unrealized gains (losses) on investments	11,898		(2,193)
Income from investment affiliate	5,348		1,477
Foreign exchange (losses) gains	(6,176)		11,162
Net income	146,373		194,361
Net (income) loss attributable to noncontrolling interest	0		0
Net income (loss) available (attributable) to Validus	146,373		194,361
Selected ratios:
Net premiums written / Gross premiums written	79.00%	[1]	83.20%	[1]
Losses and loss expenses	28.60%	[1]	24.20%	[1]
Policy acquisition costs	16.50%	[1]	17.10%	[1]
General and administrative expenses	8.50%	[1],[2]	10.20%	[1],[2]
Expense ratio	25.00%	[1]	27.30%	[1]
Combined ratio	53.60%	[1]	51.50%	[1]
Total assets	5,603,777		6,299,481
Operating Segments [Member] | AlphaCat Segment
Underwriting income
Gross premiums written	84,347		96,516
Reinsurance premiums ceded	(3,700)		0
Net premiums written	80,647		96,516
Change in unearned premiums	(49,964)		(68,899)
Net premiums earned	30,683		27,617
Underwriting deductions
Losses and loss expenses	(7,860)		0
Policy acquisition costs	2,980		2,638
General and administrative expenses	4,128		4,037
Share compensation expenses	(10)		77
Total underwriting deductions	(762)		6,752
Underwriting income (loss)	31,445		20,865
Net investment income	880		881
Other income	9,497		6,633
Finance expenses	(683)		(1,248)
Operating income (loss) before taxes and income from operating affiliates	41,139		27,131
Tax benefit	0		0
Income from operating affilates	4,927		3,523
(Income) attributable to operating affiliate investors	(31,710)		(10,077)
Net operating income (loss)	14,356		20,577
Net realized gains on investments	1,225		0
Change in net unrealized gains (losses) on investments	45,872		(4,788)
Income from investment affiliate	0		0
Foreign exchange (losses) gains	38		(1,187)
Net income	61,491		14,602
Net (income) loss attributable to noncontrolling interest	(43,509)		2,549
Net income (loss) available (attributable) to Validus	17,982		17,151
Selected ratios:
Net premiums written / Gross premiums written	95.60%	[1]	100.00%	[1]
Losses and loss expenses	(25.60%)	[1]	0.00%	[1]
Policy acquisition costs	9.70%	[1]	9.60%	[1]
General and administrative expenses	13.40%	[1],[2]	14.90%	[1],[2]
Expense ratio	23.10%	[1]	24.50%	[1]
Combined ratio	(2.50%)	[1]	24.50%	[1]
Total assets	1,582,014		1,189,190
Operating Segments [Member] | Talbot Segment
Underwriting income
Gross premiums written	290,695		293,530
Reinsurance premiums ceded	(90,605)		(94,737)
Net premiums written	200,090		198,793
Change in unearned premiums	13,798		1,517
Net premiums earned	213,888		200,310
Underwriting deductions
Losses and loss expenses	102,376		71,369
Policy acquisition costs	44,928		40,526
General and administrative expenses	35,149		30,912
Share compensation expenses	2,582		1,405
Total underwriting deductions	185,035		144,212
Underwriting income (loss)	28,853		56,098
Net investment income	4,686		4,718
Other income	17		0
Finance expenses	(26)		(74)
Operating income (loss) before taxes and income from operating affiliates	33,530		60,742
Tax benefit	130		(1,054)
Income from operating affilates	0		0
(Income) attributable to operating affiliate investors	0		0
Net operating income (loss)	33,660		59,688
Net realized gains on investments	69		128
Change in net unrealized gains (losses) on investments	2,577		(256)
Income from investment affiliate	0		0
Foreign exchange (losses) gains	(150)		(3,918)
Net income	36,156		55,642
Net (income) loss attributable to noncontrolling interest	0		0
Net income (loss) available (attributable) to Validus	36,156		55,642
Selected ratios:
Net premiums written / Gross premiums written	68.80%	[1]	67.70%	[1]
Losses and loss expenses	47.90%	[1]	35.60%	[1]
Policy acquisition costs	21.00%	[1]	20.20%	[1]
General and administrative expenses	17.60%	[1],[2]	16.10%	[1],[2]
Expense ratio	38.60%	[1]	36.30%	[1]
Combined ratio	86.50%	[1]	71.90%	[1]
Total assets	2,975,510		3,043,312
Corporate And Eliminations [Member]
Underwriting income
Gross premiums written	(42,037)		(33,249)
Reinsurance premiums ceded	42,037		33,249
Net premiums written	0		0
Change in unearned premiums	0		0
Net premiums earned	0		0
Underwriting deductions
Losses and loss expenses	0		0
Policy acquisition costs	(1,504)		(1,297)
General and administrative expenses	16,973		15,889
Share compensation expenses	2,367		(577)
Total underwriting deductions	17,836		14,015
Underwriting income (loss)	(17,836)		(14,015)
Net investment income	(969)		(3,143)
Other income	(2,454)		(17,438)
Finance expenses	(11,352)		(9,795)
Operating income (loss) before taxes and income from operating affiliates	(32,611)		(44,391)
Tax benefit	(668)		(385)
Income from operating affilates	0		0
(Income) attributable to operating affiliate investors	0		0
Net operating income (loss)	(33,279)		(44,776)
Net realized gains on investments	0		0
Change in net unrealized gains (losses) on investments	(4,654)		0
Income from investment affiliate	0		0
Foreign exchange (losses) gains	(190)		865
Net income	(38,123)		(43,911)
Net (income) loss attributable to noncontrolling interest	0		0
Net income (loss) available (attributable) to Validus	(38,123)		(43,911)
Selected ratios:
Total assets	$ 94,788		$ 32,417

[1] Ratios are based on net premiums earned.

[2] The general and administrative expense ratio includes share compensation expenses.