Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (427)	$ (97)	$ 52
Other comprehensive income (loss):
Foreign currency translation adjustments	(17)	15	(38)
Comprehensive income (loss)	$ (444)	$ (82)	$ 14