|**Life Policy And Investment Contract Reserves (Tables)**                                                                 | 12 Months Ended                                                                                                                                                                                                                                                                           
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|**Liability for Future Policy Benefits [Abstract]**                                                                       |                                                                                                                                                                                                                                                                                           
|Reserve In Addition To The Account Balance, Based on Expected No-Lapse Guarantee Benefits And Expected Policy Assessments | This table summarizes our life policy and investment contract reserves:(Dollars in millions)At December 31,20152014Traditional life$943$875Deferred annuities860863Universal life558530Structured settlements174182Other4847Total life policy and investment contract reserves$2,583$2,497
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|(Dollars in millions)                                                                                                     |                                                                                                                                                                                                                                                                                           
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|Traditional life                                                                                                          |                                                                                                                                                                                                                                                                                           
|Deferred annuities                                                                                                        |                                                                                                                                                                                                                                                                                           
|Universal life                                                                                                            |                                                                                                                                                                                                                                                                                           
|Structured settlements                                                                                                    |                                                                                                                                                                                                                                                                                           
|Other                                                                                                                     |                                                                                                                                                                                                                                                                                           
|Total life policy and investment contract reserves                                                                        |                                                                                                                                                                                                                                                                                           
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