CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Amortized Cost	$ 2,329,892	$ 2,374,816
Common stock, par value
Common stock, authorized	225,000,000	225,000,000
Common stock, shares issued	104,903,107	104,889,586
Common stock, shares outstanding	104,903,107	104,889,586

This item represents the cost of debt and equity 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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Issuance value per share of no-par value common stock; generally not indicative of the fair market value per share.

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