Income Taxes - Change in Liability for Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 58	$ 19
Increase for other tax positions of prior years	0	40
Decrease for payments and settlements	0	0
Decrease related to tax positions taken in prior years	(8)	(1)
Balance at end of year	$ 50	$ 58