Derivative Instruments - Fair Values of Derivative Instruments (Detail) - USD ($) $ in Thousands	Nov. 30, 2018	Aug. 31, 2018
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 899	$ 1,557
Liability Derivatives	2,798	1,566
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives	755	1,481
Liability Derivatives	2,647	1,212
Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives	755	700
Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	1,857	1,211
Designated as Hedging Instrument | Interest rate swap contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives		781
Designated as Hedging Instrument | Interest rate swap contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	790	1
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives	144	76
Liability Derivatives	151	354
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives	144	76
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	46	$ 354
Not Designated as Hedging Instrument | Interest rate swap contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 105