Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Beginning balance	$ 166	$ 168	$ 168
Additions based on tax positions taken in the current year	12	2	2
Additions based on tax positions of prior years	3	1	1
Reductions based on tax positions of prior years	(48)	(2)	(1)
Reductions due to settlements with taxing authorities	0	(1)	0
Reductions due to lapses in statutes of limitation	0	(2)	(2)
Ending balance	$ 133	$ 166	$ 168