Derivative Instruments - Additional Information (Detail) - Forward Contracts - USD ($) $ in Millions	3 Months Ended
Oct. 31, 2016	Oct. 31, 2015	Jul. 31, 2016
Derivative [Line Items]
Unrealized loss on cash flow hedges	$ 0.4		$ 0.2
Notional amount of cash flow hedge instruments	13.4		18.6
Cost of Revenue and Operating Expenses
Derivative [Line Items]
Realized gains (losses) on cash flow hedge instruments	(0.1)	$ (0.2)
Designated as Hedging Instrument
Derivative [Line Items]
Derivative liability, current	$ 0.6		$ 0.3

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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Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
-Paragraph 10A
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- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

+ References

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