Derivatives and Hedging Activities - Fair Values of Derivative Instruments in Consolidated Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2013	Jul. 31, 2012
Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	$ 149	$ 1,156
Liability Derivatives	98,311	99,362
Not designated as hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Asset Derivatives	1,093	78
Liability Derivatives	355	0
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	1,093	78
Other current liabilities [Member] | Foreign exchange contract [Member] | Not designated as hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	355	0
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	149	1,156
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	57	210
Net investment 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	0	0
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] | Other current liabilities [Member] | Foreign exchange contract [Member] | Designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Liability Derivatives	26	71
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	$ 98,228	$ 99,081