Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance of unrecognized tax benefits at beginning of year	$ 99	$ 75	$ 51
Gross amount of increases in unrecognized tax benefits as a result of positions taken during a prior year(1)	42	11	20
Gross amount of decreases in unrecognized tax benefits as a result of positions taken during a prior year	(3)	0	(2)
Gross amount of increases in unrecognized tax benefits as a result of positions taken during the current year	5	24	13
The amounts of decreases in unrecognized benefits relating to settlements with taxing authorities	(1)	(2)	(3)
Reduction in unrecognized tax benefits due to the lapse of applicable statute of limitation	(12)	(9)	(4)
Balance of unrecognized tax benefits at end of year	$ 130	$ 99	$ 75