Severance and Exit Costs 1 (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Accrued severance and exit costs activity
Accrued beginning balance			$ 84	$ 39
Accrued ending balance	43	76	84	39
Severance Charges [Member]
Accrued severance and exit costs activity
Accrued beginning balance	55	16
Expense	21	123
Change in estimate	(3)	(9)
Payments	(50)	(88)
Accretion and other	(1)	3
Accrued ending balance	22	45
Facility Exit Charges [Member]
Accrued severance and exit costs activity
Accrued beginning balance	29	23
Expense	0	20
Change in estimate	0	0
Payments	(7)	(9)
Accretion and other	(1)	(3)
Accrued ending balance	$ 21	$ 31