Federal Income Taxes (Reconciliation Of The Effective Tax Rate Differences) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of effective tax rate differences [Abstract]
Tax rate times pre-tax income (loss)	$ 396	$ 396	$ 510
Effect of:
Tax-preferred investment income	(87)	(280)	(196)
Tax credits	(39)	(29)	(28)
Change in uncertain tax positions	1	(17)	(14)
Excess tax benefits from share-based compensation	(5)	(12)	(8)
Goodwill impairment		316
Deferred tax impact from the Tax Cut and Jobs Act	(19)	(1,322)
Other items	(3)	(1)	2
Federal income tax expense (benefit)	$ 244	$ (949)	$ 266
Effective tax rate	13.00%	(84.00%)	18.00%

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