Derivatives and Hedging Activities - Fair Values of Derivative Instruments in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Oct. 31, 2018	Jul. 31, 2018
Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	$ 871	$ 1,076
Liability Derivatives	51,500	52,668
Not designated as hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	20	1
Liability Derivatives	52	3
Foreign exchange contract [Member] | Not designated as hedging Instruments [Member] | Prepaid expenses and other current assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	20	1
Foreign exchange contract [Member] | Not designated as hedging Instruments [Member] | Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	52	3
Unrealized gain on cash flow hedges | Foreign exchange contract [Member] | Designated as hedging instruments [Member] | Prepaid expenses and other current assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	871	1,076
Unrealized gain on cash flow hedges | Foreign exchange contract [Member] | Designated as hedging instruments [Member] | Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	452	0
Net Investment Hedging [Member] | Foreign currency denominated debt [Member] | Designated as hedging instruments [Member] | Long term obligations less current maturities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	$ 51,048	$ 52,668