CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Fixed maturities, available for sale, amortized cost	$ 12,185,973	$ 11,987,146
Equity securities, available for sale, cost	531,648	566,219
Short term investments, amortized cost	$ 107,534	$ 46,212
Common shares, shares issued	175,478us-gaap_CommonStockSharesIssued	174,134us-gaap_CommonStockSharesIssued
Common shares, shares outstanding	99,426us-gaap_CommonStockSharesOutstanding	109,485us-gaap_CommonStockSharesOutstanding
Treasury shares, shares	76,052us-gaap_TreasuryStockShares	64,649us-gaap_TreasuryStockShares

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

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This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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Amortized cost of short-term investments in debt and equity securities and other forms of securities that provide ownership interests classified as available-for-sale.

+ References

No definition available.

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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.

+ References

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

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-Name Accounting Standards Codification

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-Subparagraph (SX 210.5-02.29)

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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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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