Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Fixed maturities, available for sale, at fair value; amortized cost	$ 2,722,063	$ 3,055,477
Equity securities, trading, cost	319,320	283,107
Other investments, portion carried at fair value	$ 30,611	$ 28,958
Common shares, par value (USD per share)	$ 0.01	$ 0.01
Common shares authorized (in shares)	100,000,000	100,000,000
Common shares, shares issued (in shares)	62,503,255	62,297,214
Deferred tax expense (benefit) on accumulated other comprehensive income (loss)	$ 12,972	$ 31,342
Treasury shares, number of shares (in shares)	9,402,697	5,763,388

Amount of tax expense (benefit) allocated to accumulated other comprehensive income (loss) attributable to parent.

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Face amount or stated value per share of common stock.

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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.

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Fair value as of the balance sheet date of hybrid instruments.

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Cost of investments in equity securities and other forms of securities that provide ownership interests classified as trading.

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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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