Derivative Instruments - Fair Values of Derivative Instruments (Detail) - USD ($) $ in Thousands	Feb. 28, 2019	Aug. 31, 2018
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 733	$ 1,557
Liability Derivatives	2,813	1,566
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives	648	1,481
Liability Derivatives	2,693	1,212
Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives	648	700
Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	81	1,211
Designated as Hedging Instrument | Interest rate swap contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	781
Designated as Hedging Instrument | Interest rate swap contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	2,612	1
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives	85	76
Liability Derivatives	120	354
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives	85	76
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	98	354
Not Designated as Hedging Instrument | Interest rate swap contracts | Accounts Receivable
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	0
Not Designated as Hedging Instrument | Interest rate swap contracts | Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 22	$ 0