|**Deferred Acquisition Costs  (Tables)**                                                                              | 3 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)Three months ended March 31,20132012Deferred policy acquisition costs asset at beginning of period$470$477Capitalized deferred policy acquisition costs198170Amortized deferred policy acquisition costs(179)(156)Amortized shadow deferred policy acquisition costs2(8)Deferred policy acquisition costs asset at end of period$491$483
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|(In millions)                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                           
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|Deferred policy acquisition costs asset at beginning of period                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Capitalized deferred policy acquisition costs                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Amortized deferred policy acquisition costs                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Amortized shadow deferred policy acquisition costs                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Deferred policy acquisition costs asset at end of period                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                           

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