Investments (Range Of Credit Default Rates And Severity Rates) (Details)	12 Months Ended
Dec. 31, 2010	Dec. 31, 2009 Range Of Inputs [Member] Minimum [Member]	Dec. 31, 2009 Range Of Inputs [Member] Maximum [Member]	Dec. 31, 2009 Weighted Average Of Input [Member]
Investment [Line Items]
Credit default rate	10.30%	0.60%	11.00%	6.10%
Severity rate	49.00%	30.10%	100.00%	37.20%

This item represents the default rate of the underlying assets in the security that was considered as one of the potential factors in reaching a conclusion that the held-to-maturity investments are other than temporarily impaired and only the amount of impairment related to credit loss was recognized in earnings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 18A

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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