Basis of Presentation (Details)	3 Months Ended
Jul. 31, 2018 USD ($) $ / $	Jul. 31, 2017 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Impairment charges related to goodwill	$ 0	$ 0
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Impairment charges related to other intangible assets	0	$ 0
Foreign Exchange Forward \| Not Designated as Hedging Instrument
Finite-Lived Intangible Assets [Line Items]
Derivative, notional amount	309,400,000
Foreign Exchange Forward \| Not Designated as Hedging Instrument \| Prepaid Expenses and Other Current Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Derivative asset, fair value, gross asset	$ 800,000
Minimum \| Foreign Exchange Forward \| Not Designated as Hedging Instrument
Finite-Lived Intangible Assets [Line Items]
Derivative, forward exchange rate \| $ / $	19.72
Long \| Maximum \| Foreign Exchange Forward \| Not Designated as Hedging Instrument
Finite-Lived Intangible Assets [Line Items]
Derivative, forward exchange rate \| $ / $	20.47

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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