CONSOLIDATED BALANCE SHEETS (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fixed maturities available for sale, at amortized cost	$ 9,567,290	$ 9,165,438
Short-term investments available for sale, at amortized cost	719,848	909,121
Investment of funds received under securities lending agreements, amortized cost	42,302	48,577
Equity securities (cost)	298,414	299,058
Other investments (cost)	519,955	235,381
TALF investments amortized cost	0	373,040
Investment in joint venture cost	100,000	100,000
TALF borrowings,at par	$ 0	$ 310,868
Common shares par	$ 0.0033	$ 0.0033
Common shares (issued)	168,255,572	164,636,338
Common shares held in treasury (shares)	34,412,959	30,277,993

Equity securities - available for sale, at cost

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- Definition

The amortized cost as of the balance sheet date of securities held that had been pledged by counterparties under financing and lending arrangements, pursuant to which the entity has the right by agreement or custom to sell or re-pledge such securities.

+ References

No definition available.

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The amortized cost as of the balance sheet date of short term investments not otherwise specified in the taxonomy that will be realized in a short period of time, usually less than one year.

+ References

No definition available.

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- Definition

Par Value of asset backed securities and commercial mortgage backed securities held as part of the FRBNY Term Asset-Backed Securities Loan Facility ("TALF").

+ References

No definition available.

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Amortized cost of asset backed securities and commercial mortgage backed securities held as part of the FRBNY Term Asset-Backed Securities Loan Facility ("TALF").

+ References

No definition available.

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- Definition

This item represents the total of all debt securities grouped by maturity dates, at cost, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments, as defined), and fair value hedge accounting adjustments, if any, which are classified neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

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-Footnote 2

-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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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 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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- Definition

Face amount or stated value of common stock per share; generally not indicative of the fair market value per share.

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-Publisher SEC

-Name Regulation S-X (SX)

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

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-Name Regulation S-X (SX)

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- Definition

Includes other investments and securities that are not at fair value as of the balance sheet date and those that are not accounted for under the equity method.

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-Name Regulation S-X (SX)

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-Section 03

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- Definition

Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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-Name Regulation S-X (SX)

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