Financial Instruments Gain or Loss Related to Forward Contracts (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Forward exchange contracts \| Derivatives Not Designated as Hedging Instruments \| Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Net loss recognized in other (income) expense, net	$ 0.4	$ 2.2

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

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Balance Type:	credit
Period Type:	duration