|**Deferred Policy Acquisition Costs (Tables)**                                                                        | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|**Deferred Costs [Abstract]**                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Deferred Policy Acquisition Costs And Asset Reconciliation, Including the Amortized Deferred Policy Acquisition Costs | The table below shows the deferred policy acquisition costs and asset reconciliation:(In millions)Years ended December 31,201320122011Deferred policy acquisition costs asset, January 1$470$477$458Capitalized deferred policy acquisition costs802734661Amortized deferred policy acquisition costs(758)(706)(631)Amortized shadow deferred policy acquisition costs51(35)(11)Deferred policy acquisition costs asset, December 31$565$470$477
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|(In millions)                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|Deferred policy acquisition costs asset, January 1                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Capitalized deferred policy acquisition costs                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Amortized deferred policy acquisition costs                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Amortized shadow deferred policy acquisition costs                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Deferred policy acquisition costs asset, December 31                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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