Restructuring And Other Charges (Restructuring And Other Restructuring Plan-Related Information) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2012
Restructuring and other charges [Roll Forward]
Beginning balance	$ 78	$ 117	$ 117
Charges to operations	27		16
Charges settled in cash	(28)		(55)
Charges settled in non-cash	7	(3)
Ending balance	70		78
Fiscal 2013 Restructuring | Workforce
Restructuring and other charges [Roll Forward]
Beginning balance	0	0	0
Charges to operations	10		0
Charges settled in cash	(10)		0
Charges settled in non-cash	0
Ending balance	0		0
Fiscal 2013 Restructuring | Facilities-Related
Restructuring and other charges [Roll Forward]
Beginning balance	0	0	0
Charges to operations	4		0
Charges settled in cash	0		0
Charges settled in non-cash	(1)
Ending balance	3		0
Fiscal 2013 Restructuring | Other Reorganizational Cost
Restructuring and other charges [Roll Forward]
Beginning balance	0	0	0
Charges to operations	9		0
Charges settled in cash	(1)		0
Charges settled in non-cash	7
Ending balance	1		0
Fiscal 2011 Restructuring | Workforce
Restructuring and other charges [Roll Forward]
Beginning balance	0	3	3
Charges to operations	0		(1)
Charges settled in cash	0		(2)
Charges settled in non-cash	0
Ending balance	0		0
Fiscal 2011 Restructuring | Other Reorganizational Cost
Restructuring and other charges [Roll Forward]
Beginning balance	75	101	101
Charges to operations	5		21
Charges settled in cash	(16)		(47)
Charges settled in non-cash	0
Ending balance	64		75
Other Restructurings and Reorganization | Facilities-Related
Restructuring and other charges [Roll Forward]
Beginning balance	3	8	8
Charges to operations	(1)		(12)
Charges settled in cash	(1)		7
Charges settled in non-cash	1
Ending balance	2		3
Other Restructurings and Reorganization | Other Reorganizational Cost
Restructuring and other charges [Roll Forward]
Beginning balance	0	5	5
Charges to operations	0		8
Charges settled in cash	0		(13)
Charges settled in non-cash	0
Ending balance	$ 0		$ 0