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, 2011	Dec. 31, 2010	Mar. 31, 2011
Restructuring And Other Charges [Line Items]
Beginning balance	$ 117	$ 29	$ 29
Charges to operations	17		161
Charges settled in cash	(48)		(70)
Charges settled in non-cash	3	(1)	(3)
Ending balance	86		117
Fiscal 2011 Restructuring [Member] | Workforce [Member]
Restructuring And Other Charges [Line Items]
Beginning balance	3
Charges to operations	(1)		13
Charges settled in cash	(2)		(8)
Charges settled in non-cash			(2)
Ending balance			3
Fiscal 2011 Restructuring [Member] | Other Reorganizational Cost [Member]
Restructuring And Other Charges [Line Items]
Beginning balance	101
Charges to operations	19		135
Charges settled in cash	(40)		(32)
Charges settled in non-cash			(2)
Ending balance	80		101
Fiscal 2010 Restructuring [Member] | Workforce [Member]
Restructuring And Other Charges [Line Items]
Beginning balance		8	8
Charges to operations
Charges settled in cash			(8)
Charges settled in non-cash
Ending balance
Fiscal 2010 Restructuring [Member] | Facilities-Related [Member]
Restructuring And Other Charges [Line Items]
Beginning balance	6	11	11
Charges to operations	(3)
Charges settled in cash	(2)		(6)
Charges settled in non-cash			1
Ending balance	1		6
Fiscal 2010 Restructuring [Member] | Other Reorganizational Cost [Member]
Restructuring And Other Charges [Line Items]
Beginning balance	5	7	7
Charges to operations	12		13
Charges settled in cash	(14)		(15)
Charges settled in non-cash
Ending balance	3		5
Fiscal 2009 Restructuring [Member] | Facilities-Related [Member]
Restructuring And Other Charges [Line Items]
Beginning balance	2	3	3
Charges to operations
Charges settled in cash			(1)
Charges settled in non-cash
Ending balance	2		2
Fiscal 2008 Reorganization [Member]
Restructuring And Other Charges [Line Items]
Charges to operations	10
Fiscal 2008 Reorganization [Member] | Facilities-Related [Member]
Restructuring And Other Charges [Line Items]
Charges to operations	(10)
Charges settled in cash	$ 10