Federal Income Taxes (Federal Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income tax expense (benefit), continuing operations [Abstract]
Current	$ 179	$ 118	$ 25
Deferred	78	(1,405)	242
Federal income tax expense (benefit)	$ 257	$ (1,287)	$ 267