Balance Sheet Parenthetical (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Available-for-sale Debt Securities, Amortized Cost Basis	$ 677,040	$ 528,660
Available-for-sale Equity Securities, Amortized Cost Basis	$ 76,900	$ 76,900
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	485,000,000us-gaap_CommonStockSharesAuthorized	485,000,000us-gaap_CommonStockSharesAuthorized
Common Stock, Shares, Issued	208,974,967us-gaap_CommonStockSharesIssued	208,601,020us-gaap_CommonStockSharesIssued
Common Stock, Shares, Outstanding	191,415,726us-gaap_CommonStockSharesOutstanding	191,053,530us-gaap_CommonStockSharesOutstanding
Treasury Stock, Shares	17,559,241us-gaap_TreasuryStockShares	17,547,490us-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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