Derivative Instruments - Additional Information (Detail)	12 Months Ended
	Aug. 31, 2018 USD ($)
Foreign Exchange Contracts
Derivative [Line Items]
Aggregate derivative notional amount	$ 145,400,000
Amount reclassified to revenue or cost of revenue in the next year	1,300,000
Interest rate swap contracts
Derivative [Line Items]
Aggregate derivative notional amount	$ 85,100,000
Maturity date	2020-03
Unrealized pre-tax gain (loss) that would be reclassified to interest expense in the next year	$ 100,000