Investments (Details 3) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Due in one year or less, Amortized Cost	$ 67,805
Due after one year through five years, Amortized Cost	161,830
Due after five years through ten years, Amortized Cost	88,205
Due after ten years, Amortized Cost	51,858
Debt Maturities, Amortized Cost	403,554
Due in one year or less, Fair Value	68,784
Due after one year through five years, Fair Value	163,838
Due after five years through ten years, Fair Value	89,711
Due after ten years, Fair Value	51,463
Debt Securities, Fair Value	407,741	401,435
Collateralized Mortgage Backed Securities [Member]
Debt Maturities, Amortized Cost	33,856
Debt Securities, Fair Value	$ 33,945	$ 9,724

Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the sixth fiscal year through the tenth fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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