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Investments (Gross Credit Loss Impairments of Fixed Maturity Securities for Which a Portion of the OTTI Charge was Recognized in OCI) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Investments [Abstract]
Balance, beginning of period	$ 17,723	$ 22,189	$ 0
Credit losses remaining in retained earnings after adoption of OTTI accounting guidance	0	0	9,719
Addition for the amount related to credit loss for which an OTTI was not previously recognized	0	2,326	10,579
Reductions for securities sold during the period	0	(2,990)	0
Reductions for securities for which the amount previously recognized in OCI was recognized in earnings because of intention or potential requirement to sell before recovery of amortized cost	0	0	0
Reductions for securities for which the entire amount previously recognized in OCI was recognized in earnings due to a decrease in cash flows expected	(11,672)	(8,143)	(693)
Additional increases to the amount related to credit loss for which an OTTI was previously recognized	551	4,341	2,584
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	0	0	0
Balance, end of year	$ 6,602	$ 17,723	$ 22,189

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- Definition

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This item represents an increase to the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security held for which a previous OTTI was recognized and the investor does not intend to sell the debt security and it is not more likely than not that the investor will be required to sell the debt security before recovery of its amortized cost basis.

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The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

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