Royalties And Licenses (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Royalties And Licenses [Line Items]
Royalty Related Loss And Or Impairment Charges				$ (35)
Impairment charges	1	31	6		39	12
Loss on unrecognized minimum royalty				18	15
Royalty-related liabilities (including restructuring)	133	170		133	170
Unrecorded unconditional purchase obligation	1,734			1,734
Developer/Licensor Commitments
Royalties And Licenses [Line Items]
Unrecorded unconditional purchase obligation	1,301			1,301
Fiscal 2013 Restructuring [Member]
Royalties And Licenses [Line Items]
Loss on unrecognized minimum royalty					9
Royalty-related liabilities (including restructuring)	1			1
Fiscal 2011 Restructuring
Royalties And Licenses [Line Items]
Royalty-related liabilities (including restructuring)	$ 47			$ 47