Derivative Instruments - Additional Information (Detail)	3 Months Ended
	Nov. 30, 2018 USD ($)
Foreign Exchange Contracts
Derivative [Line Items]
Aggregate derivative notional amount	$ 139,800,000
Amount reclassified to revenue or cost of revenue in the next year	2,400,000
Interest rate swap contracts
Derivative [Line Items]
Aggregate derivative notional amount	$ 112,500,000
Maturity date	2023-09
Unrealized pre-tax gain (loss) that would be reclassified to interest expense in the next year	$ 800,000