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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	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Investments [Abstract]
Balance, beginning of period	$ 7,477	$ 6,602
Addition for the amount related to credit loss for which an OTTI was not previously recognized	0	0
Reductions for securities sold during the period	0	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
Reductions for securities for which the entire amount previously recognized in OCI was recognized in earnings due to a decrease in cash flows expected	0	0
Additional increases to the amount related to credit loss for which an OTTI was previously recognized	9	109
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	0	0
Balance, end of period	$ 7,486	$ 6,711

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- Definition

This item represents accretion of credit loss impairments previously recognized due to an increase in cash flow expected to be collected on securities for which an other-than-temporary impairment charge was recognized in other comprehensive income.

+ References

No definition available.

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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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-Name Accounting Standards Codification

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- Definition

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 no such other than temporary impairment (OTTI) was previously recognized.

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- Definition

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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- Definition

This item represents reductions in the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security held due to increases in cash flows expected to be collected and recognized over the remaining life of the security.

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This item represents reductions in the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security because of the sale of impaired securities during the period.

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