CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fixed maturities, available for sale, amortized cost	$ 6,479,270	$ 6,375,237
Equity securities, available for sale, cost	$ 99,860	$ 99,904
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000us-gaap_PreferredStockSharesAuthorized	1,000,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, shares issued	0us-gaap_PreferredStockSharesIssued	0us-gaap_PreferredStockSharesIssued
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	75,000,000us-gaap_CommonStockSharesAuthorized	75,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	64,454,178us-gaap_CommonStockSharesIssued	64,245,048us-gaap_CommonStockSharesIssued
Treasury stock, shares	23,331,930us-gaap_TreasuryStockShares	23,308,430us-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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