Restructuring And Other Charges (Restructuring And Other Restructuring Plan-Related Information) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Sep. 30, 2014	Mar. 31, 2014
Restructuring and other charges [Roll Forward]
Beginning balance	$ 50	$ 62
Charges to operations	0	(1)
Charges settled in cash	(15)	(11)
Ending balance	35	50
Fiscal 2011 Restructuring | Other Restructuring Costs [Member]
Restructuring and other charges [Roll Forward]
Beginning balance	47	57
Charges to operations	0	(2)
Charges settled in cash	(15)	(8)
Ending balance	32	47
Other Restructurings And Reorganization Costs [Member] | Facilities-Related
Restructuring and other charges [Roll Forward]
Beginning balance	2	4
Charges to operations	0	1
Charges settled in cash	0	(3)
Ending balance	2	2
Other Restructurings and Reorganization | Other Restructuring Costs [Member]
Restructuring and other charges [Roll Forward]
Beginning balance	1	1
Charges to operations	0	0
Charges settled in cash	0	0
Ending balance	$ 1	$ 1