Federal Income Taxes (Federal Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income tax expense (benefit), continuing operations [Abstract]
Current	$ (61)	$ 181	$ 91
Deferred	(15)	(148)	153
Federal income tax expense (benefit)	$ (76)	$ 33	$ 244