Significant accounting policies (Policies)	6 Months Ended
Jun. 30, 2011
Accounting Policies [Abstract]
Basis of preparation	These unaudited consolidated financial statements include Validus Holdings, Ltd. and its wholly and majority owned subsidiaries (together, the “Company”) and have been prepared in accordance with generally accepted accounting principles 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 for the year ended December 31, 2010, 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 (consisting of normal recurring accruals) 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.
Use of estimates	All significant 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. Actual results could differ from these estimates. The major 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, the valuation of goodwill and intangible assets, reinsurance recoverable balances including the provision for unrecoverable reinsurance recoverable balances and investment valuation. Actual results could differ from those estimates.
Investments	The Company’s investments in fixed maturities are classified as trading and carried at fair value, with related net unrealized gains or losses included in earnings. 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.
Reserves for losses and loss expenses	Reserves for losses and loss expenses are based in part upon the estimation of case losses 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, the reporting of a loss to the Company and 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, case 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 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 the total reserves.
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.

Significant accounting policies (Policies)

6 Months Ended

Jun. 30, 2011

These unaudited consolidated financial statements include Validus Holdings, Ltd. and its wholly and majority owned subsidiaries (together, the “Company”) and have been prepared in accordance with generally accepted accounting principles 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 for the year ended December 31, 2010, 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 (consisting of normal recurring accruals) 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.

Use of estimates

All significant 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. Actual results could differ from these estimates. The major 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, the valuation of goodwill and intangible assets, reinsurance recoverable balances including the provision for unrecoverable reinsurance recoverable balances and investment valuation. Actual results could differ from those estimates.

Investments

The Company’s investments in fixed maturities are classified as trading and carried at fair value, with related net unrealized gains or losses included in earnings. 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.

Reserves for losses and loss expenses

Reserves for losses and loss expenses are based in part upon the estimation of case losses 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, the reporting of a loss to the Company and 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, case 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 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 the total reserves.

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.

- Definition

Disclosure of accounting policy for investments in debt and equity securities that are classified as trading securities. This policy also may describe the entity's accounting treatment for transfers between investment categories and how the fair values of such securities are determined.

+ References+ Details

- Definition

Disclosure of accounting policy for ceded reinsurance transactions on the financial statements, and description of the methodologies and assumptions underlying determination of reinsurance recoverables and reinsurance payables. If applicable, the assumptions pertaining to foreign-based reinsurance, and the nature and effect of material nonrecurring reinsurance transactions. May also state that the ceding insurer is not relieved of its primary obligation to policyholders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.13(c))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 113
-Paragraph 27, 120
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=6588590&loc=d3e27830-158548

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 7
-Section 03
-Paragraph 13
-Subparagraph c

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 55
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=6588590&loc=d3e27758-158548

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-URI http://asc.fasb.org/topic&trid=2303980

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6816-158387

+ Details

- Definition

Disclosure of accounting policy for estimating the ultimate cost of settling insurance claims relating to insured events that have occurred on or before a particular date (ordinarily, the statement of financial position date). The estimated liability includes the amount of money that will be required for future payments of (a) claims that have been reported to the insurer, (b) claims related to insured events that have occurred but that have not been reported to the insurer as of the date the liability is estimated, and (c) claim adjustment expenses. Claims adjustment expenses include costs incurred in the claim settlement process such as legal fees; outside adjuster fees; and costs to record, process, and adjust claims.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 94-5
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 60
-Paragraph 60
-Subparagraph a, b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.13(b))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 7
-Section 03
-Paragraph 13
-Subparagraph b

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Audit and Accounting Guide (AAG)
-Number AAG-PLI
-Chapter 4
-Paragraph 2, 34, 132, 133
-IssueDate 2006-09-01
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14754-158437

+ Details

- Definition

Disclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles.

+ References+ Details