Royalties And Licenses (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended				12 Months Ended
	Mar. 31, 2013	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2013 Developer/Licensor Commitments [Member]	Mar. 31, 2013 Fiscal 2013 Restructuring [Member]	Mar. 31, 2012 Fiscal 2011 Restructuring [Member]	Mar. 31, 2011 Fiscal 2011 Restructuring [Member]	Mar. 31, 2013 Fiscal 2011 Restructuring [Member]
Royalties And Licenses [Line Items]
Royalty liabilities are classified as current liabilities to the extent such royalty payments are contractually due within this period	12 months
Losses on unrecognized royalty-based commitments	$ (15)	$ (85)			$ (9)	$ (21)	$ (75)
Impairment charges on long lived assets		40					27
Restructuring accrual included in royalty-related liabilities	170		173		1			57
Unrecorded Unconditional Purchase Obligation	$ 1,597			$ 1,144