Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net income (loss)	$ (22)	$ (38)	$ 622	$ 402
Other comprehensive income (loss), net of tax:
Net gains (losses) on available-for-sale securities	0	(2)	0	0
Net gains (losses) on derivative instruments	(34)	(5)	(90)	17
Foreign currency translation adjustments	32	(6)	36	(11)
Total other comprehensive income (loss), net of tax	(2)	(13)	(54)	6
Total comprehensive income (loss)	$ (24)	$ (51)	$ 568	$ 408