Income Taxes (Provision For (Benefit From) Income Taxes) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]
Federal, Current	$ (2)	$ 0	$ 36
State, Current	1	0	3
Foreign, Current	8	39	(11)
Total, Current	7	39	28
Federal, Deferred	(9)	5	(89)
State, Deferred	(2)	1	(2)
Foreign, Deferred	3	(4)	5
Total, Deferred	(8)	2	(86)
Total, Federal	(11)	5	(53)
Total, State	(1)	1	1
Total, Foreign	11	35	(6)
Total provision for (benefit from) income taxes	$ (1)	$ 41	$ (58)