Derivatives and Hedging Activities - Fair Values of Derivative Instruments in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated other comprehensive loss	$ (69,668)		$ (66,477)	$ (71,254)
Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(211)	$ 381
Prepaid expenses and other current assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Assets	1,017		594
Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Liabilities	(449)		777
Unrealized (loss) gain on cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Net gain recognized in other comprehensive loss	697	$ 196
Unrealized (loss) gain on cash flow hedges | Designated as hedging instruments [Member] | Prepaid expenses and other current assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Assets	1,017		588
Unrealized (loss) gain on cash flow hedges | Designated as hedging instruments [Member] | Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Liabilities	$ (434)		$ 761