Royalties And Licenses (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended		90 Months Ended		3 Months Ended	6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2022	Sep. 30, 2014 Developer/Licensor Commitments	Sep. 30, 2013 Unrecognized Royalty-Based Commitment Losses	Sep. 30, 2013 Royalty-Based Asset Losses
Royalties And Licenses
Royalty Related Loss and Or Impairment Charges	$ 122
Expected accretion expense			33
Loss on Contract Termination		27			10	17
Unrecorded Unconditional Purchase Obligation	$ 1,577			$ 1,066