Stock-Based Compensation - Annual Activity Of Stock Units and Cash Units (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Weighted Average Grant Date Fair Value
Fair value vested in period	$ 17	$ 19	$ 18
Cost not yet recognized	$ 31
Period for recognition	1 year 1 month 6 days
Time-based RSUs
Number of Shares
Balance (in shares)	1,070
Granted (in shares)	245
Vested (in shares)	(590)
Forfeited (in shares)	(54)
Balance (in shares)	671	1,070
Weighted Average Grant Date Fair Value
Balance (in dollars per share)	$ 27.47
Granted (in dollars per share)	65.23	$ 23.14	$ 34.14
Vested (in dollars per share)	29.16
Forfeited (in dollars per share)	31.82
Balance (in dollars per share)		$ 27.47
Outstanding and expected to vest, weighted average grant date fair value (in dollars per share)	$ 39.39
Outstanding and expected to vest weighted average remaining contractual term (in years)	10 months 24 days
Aggregate intrinsic value, outstanding and expected to vest	$ 139
Performance-based and market-based RSUs
Number of Shares
Balance (in shares)	988
Granted (in shares)	236
Vested (in shares)	0
Forfeited (in shares)	(338)
Balance (in shares)	886	988
Outstanding and expected to vest (in shares)	886
Weighted Average Grant Date Fair Value
Balance (in dollars per share)	$ 32.41
Granted (in dollars per share)	62.27	$ 21.06	$ 34.56
Vested (in dollars per share)	0
Forfeited (in dollars per share)	45.39
Balance (in dollars per share)	35.40	$ 32.41
Outstanding and expected to vest, weighted average grant date fair value (in dollars per share)	$ 35.40
Outstanding and expected to vest weighted average remaining contractual term (in years)	1 year 3 months 18 days
Outstanding weighted average remaining contractual terms (in years)	1 year 3 months 18 days
Aggregate intrinsic value, outstanding and expected to vest	$ 184
Aggregate intrinsic value outstanding	$ 184