Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of unrecognized tax benefits [Roll Forward]:
Unrecognized tax benefits, beginning of year	$ 16	$ 3	$ 35
Increases – tax positions taken in prior years	0	13	0
Decreases – tax positions taken in prior years	(13)	0	0
Settlements	0	0	(32)
Lapse of statute of limitations	0	0	0
Unrecognized tax benefits, end of year	$ 3	$ 16	$ 3