Derivatives and Hedging Activities - Fair Values of Derivative Instruments in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Oct. 31, 2017	Jul. 31, 2017
Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	$ 173	$ 1,067
Liability Derivatives	53,236	54,849
Not designated as hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	2	287
Liability Derivatives	6	7
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	2	287
Foreign exchange contract [Member] \| Not designated as hedging Instruments [Member] \| Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	6	7
Cash Flow Hedging [Member] \| Foreign exchange contract [Member] \| Designated as hedging instruments [Member] \| Prepaid expenses and other current assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	173	1,067
Cash Flow Hedging [Member] \| Foreign exchange contract [Member] \| Designated as hedging instruments [Member] \| Other current liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	815	1,569
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	$ 52,421	$ 53,280