Fair Value Measurements - Summary Fair Value of Outstanding Derivative Instruments (Detail) $ in Thousands	Apr. 30, 2017 USD ($)
Foreign currency derivative contracts [Member] \| Derivatives not designated as hedging instruments [Member] \| Prepaid expenses and other current assets [Member]
Derivatives Fair Value [Line Items]
Derivative Assets	$ (49)

Fair value as of the balance sheet date of all foreign currency derivatives not designated as hedging instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

Name:	us-gaap_ForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAtFairValueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant