Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 80	$ 112	$ 154	$ 138
Other comprehensive (loss) income, net of income taxes:
Currency translation adjustment		1		(1)
Interest rate derivatives	(1)		2
Other comprehensive (loss) income, net of income taxes	(1)	1	2	(1)
Comprehensive income	$ 79	$ 113	$ 156	$ 137