Consolidated Statements of Other Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Net income	$ 967	$ 1,156	$ 875
Other comprehensive income (loss), net of tax:
Change in unrealized net gains and losses on available-for-sale securities	(3)	4	1
Reclassification adjustment for net realized gains and losses on available-for-sale securities	(1)	0	0
Change in unrealized net gains and losses on derivative instruments	54	5	20
Reclassification adjustment for net realized gains and losses on derivative instruments	(36)	(12)	11
Foreign currency translation adjustments	(17)	(15)	(67)
Total other comprehensive loss, net of tax	(3)	(18)	(35)
Total comprehensive income	$ 964	$ 1,138	$ 840