|**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:(Dollars in millions)Years ended December 31,201420132012Deferred policy acquisition costs asset, January 1$565$470$477Capitalized deferred policy acquisition costs827802734Amortized deferred policy acquisition costs(807)(758)(706)Amortized shadow deferred policy acquisition costs(7)51(35)Deferred policy acquisition costs asset, December 31$578$565$470
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|(Dollars 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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