Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 27	$ 34	$ 40	$ 64
Other comprehensive income (loss):
Foreign currency translation adjustments	[1]	13	(8)	20	1
Total other comprehensive income (loss)		13	(8)	20	1
Comprehensive income		$ 40	$ 26	$ 60	$ 65

[1] Foreign currency translation adjustments exclude income taxes due to our practice and intention to indefinitely reinvest the earnings of our foreign subsidiaries in those operations.