Severance and Exit Costs 1 (Details) (USD $) In Millions, unless otherwise specified					6 Months Ended
	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2014 Severance Charges [Member]	Sep. 30, 2013 Severance Charges [Member]	Sep. 30, 2014 Facility Exit Charges [Member]	Sep. 30, 2013 Facility Exit Charges [Member]
Accrued severance and exit costs activity
Accrued beginning balance	$ 53	$ 84	$ 85	$ 39	$ 55	$ 16	$ 29	$ 23
Expense					21	111	0	19
Change in estimate					(1)	(9)	0	0
Payments					(43)	(69)	(5)	(6)
Accretion and other					(2)	3	(1)	(3)
Accrued ending balance	$ 53	$ 84	$ 85	$ 39	$ 30	$ 52	$ 23	$ 33