Fair Value Measurements - Summary Fair Value of Outstanding Derivative Instruments (Detail) - Foreign currency derivative contracts - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019
Derivatives, Fair Value [Line Items]
Notional amount of foreign currency derivative contracts	$ (65,258)	$ (5,112)
Fair value of foreign currency derivative contracts	$ (65,209)	$ (5,024)

Fair value of the assets less the liabilities of a derivative or group of derivatives.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

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