Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 212	$ 174	$ 410	$ 386
Other comprehensive income (loss):
Foreign currency translation adjustments	10	(53)	(19)	(21)
Total other comprehensive income (loss)	10	(53)	(19)	(21)
Comprehensive income	$ 222	$ 121	$ 391	$ 365