Royalties And Licenses (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended		9 Months Ended
	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2012 Fiscal 2013 Restructuring	Dec. 31, 2011 Fiscal 2011 Restructuring	Dec. 31, 2012 Fiscal 2011 Restructuring	Dec. 31, 2012 Developer/Licensor Commitments
Royalties And Licenses
Loss on unrecognized minimum royalty	$ 15		$ 9	$ 14
Royalty-related liabilities (including restructuring)	196	173	1		64
Unrecorded Unconditional Purchase Obligation	$ 1,648					$ 1,166