Derivatives and Hedging Activities - Fair Values of Derivative Instruments in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jan. 31, 2021	Jul. 31, 2020
Derivatives, Fair Value [Line Items]
Document Period End Date	Jan. 31, 2021
Prepaid expenses and other current assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 1,246	$ 594
Other current liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	499	777
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Prepaid expenses and other current assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	1,241	588
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Other current liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	499	761
Not designated as hedging Instruments [Member] | Cash Flow Hedging [Member] | Prepaid expenses and other current assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	5	6
Not designated as hedging Instruments [Member] | Cash Flow Hedging [Member] | Other current liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 0	$ 16