Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Current - U.S. Federal	$ 486	$ 410	$ 8
International	2	0	0
Total current	488	410	8
Deferred - U.S. Federal	49	(20)	476
International	(6)	(7)	(9)
Total deferred	43	(27)	467
Total income tax expense (benefit)	$ 531	$ 383	$ 475