Income Taxes - Total income tax provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current taxes:
Federal	$ 101	$ 250	$ 196
State	6	10	8
Foreign	3	2	0
Deferred taxes:
Federal	17	(23)	(82)
Provision for income taxes as shown in the Statement of Earnings	$ 127	$ 239	$ 122