Royalties And Licenses (Schedule Of Royalty-Related Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Mar. 31, 2017
Royalty Related Liabilities
Royalty-related liabilities	$ 340	$ 262
Accrued royalties
Royalty Related Liabilities
Royalty-related liabilities	260	165
Other liabilities
Royalty Related Liabilities
Royalty-related liabilities	$ 80	$ 97

Carrying value as of the balance sheet date of obligations incurred through that date and payable for royalties.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(5))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.15(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant