Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 247	$ 289
Other comprehensive income:
Fair market value adjustment on cash flow hedges, net of income tax provision of $1 million	2	0
Reclassification adjustment for net realized losses on cash flow hedges included in interest expense, net of income tax provision of $1 million in each period	2	2
Foreign currency translation	5	3
Total other comprehensive income	9	5
Comprehensive income	$ 256	$ 294