Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net income (loss)	$ 3	$ (273)	$ 338	$ (51)
Other comprehensive income (loss), net of tax:
Change in unrealized net gains and losses on available-for-sale securities	0	1	0	0
Change in unrealized net gains and losses on derivative instruments	11	(9)	10	(11)
Reclassification adjustment for net realized losses on derivative instruments	2	0	7	2
Foreign currency translation adjustments	(21)	14	(1)	2
Total other comprehensive income (loss), net of tax	(8)	6	16	(7)
Total comprehensive income (loss)	$ (5)	$ (267)	$ 354	$ (58)