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Federal Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Reconciliation of unrecognized tax benefits [Roll Forward]    
Balance as of beginning-of-year $ 51 $ 48
Increases for prior year tax positions 2  
Increases for current year tax positions   3
Balance as of end-of-year $ 53 $ 51