Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 222	$ 232	$ 695	$ 807
Other comprehensive loss:
Foreign currency translation adjustments	(78)	(10)	(162)	(30)
Total other comprehensive loss	(78)	(10)	(162)	(30)
Comprehensive income	$ 144	$ 222	$ 533	$ 777