Derivatives and Hedging Activities - Fair Values of Derivative Instruments in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Jul. 31, 2017	Jul. 31, 2016
Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	$ 1,067	$ 265
Liability Derivatives	54,849	117,558
Not designated as hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	287	1,873
Liability Derivatives	7	68
Prepaid expenses and other current assets [Member] | Foreign exchange contract [Member] | Not designated as hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	287	1,873
Other current liabilities [Member] | Foreign exchange contract [Member] | Not designated as hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	7	68
Cash flow hedging [Member] | Prepaid expenses and other current assets [Member] | Foreign exchange contract [Member] | Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	1,067	265
Cash flow hedging [Member] | Other current liabilities [Member] | Foreign exchange contract [Member] | Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	1,569	670
Net investment hedging [Member] | Prepaid expenses and other current assets [Member] | Foreign currency denominated debt [Member] | Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	0	0
Net investment hedging [Member] | Long term obligations less current maturities [Member] | Foreign currency denominated debt [Member] | Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	$ 53,280	$ 116,888