Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 783	$ 846	$ 914
Other comprehensive income (loss):
Foreign currency translation adjustments	2	(247)	(16)
Total other comprehensive income (loss)	2	(247)	(16)
Comprehensive income	$ 785	$ 599	$ 898