(Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Mar. 31, 2017
Other liabilities \| Fair Value, Inputs, Level 3 [Member] \| Contingent consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Accrued Liabilities, Fair Value Disclosure	$ 122	$ 0

Fair value portion of accrued expenses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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