Fair Values of Derivative Instruments (Detail) (USD $) In Thousands, unless otherwise specified	May 31, 2013	Aug. 31, 2012
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 1,058	$ 2,703
Designated as Hedging Instrument | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	2,382	3,043
Designated as Hedging Instrument | Foreign Currency Forward Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	723	182
Designated as Hedging Instrument | Foreign Currency Forward Exchange Contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives	1,058	2,703
Designated as Hedging Instrument | Interest Rate Swap | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	1,659	2,861
Not Designated as Hedging Instrument | Foreign Currency Forward Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	113	102
Not Designated as Hedging Instrument | Foreign Currency Forward Exchange Contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 184	$ 141