Severance and Exit Costs 2 (Details) (USD $) In Millions, unless otherwise specified	20 Months Ended
	Dec. 31, 2014 Employee	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Restructuring Cost and Reserve [Line Items]
Accrued balance	$ 43	$ 84	$ 76	$ 39
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Accrued balance	22	55	45	16
Facility Exit [Member]
Restructuring Cost and Reserve [Line Items]
Accrued balance	21	29	31	23
Fiscal 2014 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Workforce rebalancing (number of employees)	1,900
Expected cost	191
Fiscal 2014 Plan [Member] | Severance [Member]
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	169
Fiscal 2014 Plan [Member] | Facility Exit [Member]
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	22
Plans and Actions Prior to Fiscal 2014 Plan [Member] | Severance [Member]
Restructuring Cost and Reserve [Line Items]
Accrued balance			5
Plans and Actions Prior to Fiscal 2014 Plan [Member] | Facility Exit [Member]
Restructuring Cost and Reserve [Line Items]
Accrued balance	$ 10		$ 14