|**Life Policy and Investment Contract Reserves (Tables)**              | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                            
|---------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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|**Liability for Future Policy Benefit, before Reinsurance [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                           
|Reserve For Losses Loss Adjustment Expenses Table                      | This table summarizes our life policy and investment contract reserves:(Dollars in millions)March 31,2022December 31,2021Life policy reserves:Ordinary/traditional life$1,395$1,376Other5252Subtotal1,4471,428Investment contract reserves:Deferred annuities757762Universal life680679Structured settlements135136Other89Subtotal1,5801,586Total life policy and investment contract reserves$3,027$3,014
|                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                           
|(Dollars in millions)                                                  |                                                                                                                                                                                                                                                                                                                                                                                                           
|Life policy reserves:                                                  |                                                                                                                                                                                                                                                                                                                                                                                                           
|Ordinary/traditional life                                              |                                                                                                                                                                                                                                                                                                                                                                                                           
|Other                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                           
|Subtotal                                                               |                                                                                                                                                                                                                                                                                                                                                                                                           
|Investment contract reserves:                                          |                                                                                                                                                                                                                                                                                                                                                                                                           
|Deferred annuities                                                     |                                                                                                                                                                                                                                                                                                                                                                                                           
|Universal life                                                         |                                                                                                                                                                                                                                                                                                                                                                                                           
|Structured settlements                                                 |                                                                                                                                                                                                                                                                                                                                                                                                           
|Other                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                           
|Subtotal                                                               |                                                                                                                                                                                                                                                                                                                                                                                                           
|Total life policy and investment contract reserves                     |                                                                                                                                                                                                                                                                                                                                                                                                           
|                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                           

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