Severance and Exit Costs 1 (Details) (USD $) In Millions, unless otherwise specified					9 Months Ended
	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2013 Severance Charges [Member]	Dec. 31, 2012 Severance Charges [Member]	Dec. 31, 2013 Facility Exit Charges [Member]	Dec. 31, 2012 Facility Exit Charges [Member]
Severance and exit costs activity
Accrued beginning balance	$ 76	$ 39	$ 45	$ 53	$ 16	$ 13	$ 23	$ 40
Expense					123	18	20	0
Change in estimate					(9)	(3)	0	0
Payments					(88)	(8)	(9)	(11)
Accretion and other					3	0	(3)	(4)
Accrued ending balance	$ 76	$ 39	$ 45	$ 53	$ 45	$ 20	$ 31	$ 25