The percentage points added to the reference rate to compute the variable rate on the debt instrument.

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- Definition

The earliest date, before maturity, on which the issuer can call the outstanding debt instrument for repayment or conversion to equity, which may be presented in a variety of ways (year only, month and year, day, month and year, quarter, etc.).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (e)
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

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- Definition

Date that the debt agreement requires the first payment to be made, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
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-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Section 50
-Paragraph 3
-Subparagraph (c)
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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

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- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 21
-Paragraph 16, 20
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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-Paragraph 2
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-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

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- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 942
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-Paragraph 3
-Subparagraph (c)
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph 2, 4
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
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-Article 5

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-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Interest rate stated in the contractual debt agreement.

+ References

+ Details

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- Definition

Date when the debt instrument was issued, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

+ References

+ Details

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- Definition

Date when the debt instrument is scheduled to be fully repaid, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph 2, 4
-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.

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-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Gross amount of debt extinguished.

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 45
-Paragraph 13
-Subparagraph 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.

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-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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- Definition

Reflects when the credit facility first became available, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph 2, 4
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-Publisher SEC
-Name Regulation S-X (SX)
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-Article 5

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4
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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
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-Paragraph 19, 22
-Article 5

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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 95-13
-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 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3291-108585

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from a borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in liquidation of the entity's assets or underlying collateral.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Credit Facilities.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Length of redemption period, in years.

+ Details

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Namespace Prefix:	vr
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Period Type:	duration

- Definition

The number of years for which the credit facility is available.

+ Details

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Period Type:	duration

- Definition

The date on which the terms of a given facility were amended.

+ Details

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Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility prior to any amendments or refinancing.

+ Details

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Namespace Prefix:	vr
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum level of consolidated net worth required by covenant.

+ Details

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- Definition

Percentage of net proceeds from issuance of common shares that is required to be added to the minimum level of consolidated net worth each quarter beginning in the first quarter ending after the date of the agreement, as required by covenant.

+ Details

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Percentage of consolidated net income (if positive) that is required to be added to the minimum level of consolidated net worth each quarter beginning in the first quarter ending after the date of the agreement, as required by covenant.

+ Details

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- Definition

The initial percentage of consolidated net worth required to be maintained as required by covenant.

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- Definition

The maximum allowable ratio of consolidated total debt to consolidated total capitalization that the Company must maintain at all times, as required by covenant.

+ Details

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- Definition

Senior notes and junior debentures.

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Debt and financing Arrangements (Details Textuals) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2009	Dec. 31, 2010
Jun 15 2006- Jun15 2011 [Member] \| 2006 Junior Subordinated Deferrable Debentures [Member]
Senior Notes and Junior Debentures
Interest rate	9.069%
Jun 21 2007 - Jun 15 2012 [Member] \| 2007 Junior Subordinated Deferrable Debentures [Member]
Senior Notes and Junior Debentures
Interest rate	8.48%
June 15 2011 June 15 2036 [Member] \| 2006 Junior Subordinated Deferrable Debentures [Member]
Senior Notes and Junior Debentures
Debt instrument maturity date	Jun. 15, 2036
Description of variable rate basis	3 month LIBOR
Basis spread on variable rate	3.55%
June 15 2012 June 15 2037 [Member] \| 2007 Junior Subordinated Deferrable Debentures [Member]
Senior Notes and Junior Debentures
Debt instrument maturity date	Jun. 15, 2037
Description of variable rate basis	3 month LIBOR
Basis spread on variable rate	2.95%
2006 Junior Subordinated Deferrable Debentures [Member]
Senior Notes and Junior Debentures
Length of optional redemption period	5 years
Debt issuance cost	$ 3,750
Debt instrument issuance date	2006-06-15
Debt instrument, commitment	150,000		150,000
Frequency of required payments	Quarterly
Start of optional redemption period	Jun. 15, 2011
Gross proceeds on issuance of junior subordinated deferrable debentures	150,000
2007 Junior Subordinated Deferrable Debentures [Member]
Senior Notes and Junior Debentures
Length of optional redemption period	5 years
Debt issuance cost	2,000
Cumulative amount repurchased from an unaffiliated financial institution		60,200
Debt instrument issuance date	2007-06-21
Debt instrument, commitment	200,000		200,000
Frequency of required payments	Quarterly
Start of optional redemption period	Jun. 15, 2012
Gross proceeds on issuance of junior subordinated deferrable debentures	200,000
2010 Senior Notes Due 2040 [Member]
Senior Notes and Junior Debentures
Interest rate	8.875%
Debt issuance cost	2,808
Debt instrument issuance date	2010-01-21
Debt instrument maturity date	Jan. 26, 2040
Date of first required payment	2010-07-26
Debt instrument, commitment	250,000		250,000
2010 Senior Notes [Member]
Senior Notes and Junior Debentures
Net proceeds on issuance of senior notes	243,967
Secured letter of credit facility [Member]
Credit Facilities
Letter of credit facility amount issued and outstanding	277,679		268,944
Line of credit facility initiation date	2007-03-12
Letter of credit facility, commitment	500,000		500,000
Bilateral unsecured letter of credit facility [Member]
Credit Facilities
Letter of credit facility period	3 years
Letter of credit facility amount issued and outstanding	0		0
Letter of credit facility, commitment	60,000		60,000
Ipc Bi Lateral Facility [Member]
Credit Facilities
Letter of credit facility amount issued and outstanding	63,284		68,063
Letter of credit facility, commitment	80,000		80,000
Talbot Fal Facility [Member]
Credit Facilities
Letter of credit facility amount issued and outstanding	25,000		25,000
Letter of credit facility, original commitment amount	100,000
Line of credit facility initiation date	2007-11-28
Line of credit facility amendment date	2009-11-19
Letter of credit facility, commitment	25,000		25,000
Percent of consolidated net income quarterly increase under covenant	50.00%
Percent of minimum level of consolidated net worth under covenant	70.00%
Percent of any net proceeds from issuance of common shares	50.00%
Ratio consolidated total debt to net worth under covenant	not greater than 0.35:1.00
Minimum level of consolidated net worth	2,607,219
Syndicated unsecured letter of credit facility [Member]
Credit Facilities
Letter of credit facility amount issued and outstanding	0		0
Letter of credit facility, commitment	340,000		340,000
Unsecured letter of credit facility [Member]
Credit Facilities
Letter of credit facility period	5 years
Line of credit facility initiation date	2010-03-12
Three Year Facilities Credit Facilities [Member]
Credit Facilities
Letter of credit facility amount issued and outstanding	0		0
Letter of credit facility, commitment	340,000
Credit Facilities [Member]
Credit Facilities
Letter of credit facility, original commitment amount	100,000
Line of credit facility amendment date	2009-09-04
Percent of consolidated net income quarterly increase under covenant	50.00%
Percent of minimum level of consolidated net worth under covenant	70.00%
Percent of any net proceeds from issuance of common shares	50.00%
Ratio consolidated total debt to net worth under covenant	not greater than 0.35:1.00
Minimum level of consolidated net worth	$ 2,925,590