Summary of Significant Accounting Policies - Amounts Reclassified out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2021	Aug. 31, 2020	Aug. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest and foreign exchange	$ 43,263	$ 43,619	$ 30,912
Total before tax	8,580	(124,810)	(153,204)
Tax expense	(40,223)	40,184	$ 41,588
Unrealized (Gain) Loss on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total before tax	6,669	5,641
Tax expense	(1,690)	(1,466)
Net of tax	4,979	4,175
Unrealized (Gain) Loss on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive loss | Foreign Exchange Contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Revenue and Cost of revenue	1,408	2,984
Unrealized (Gain) Loss on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive loss | Interest rate swap contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest and foreign exchange	$ 5,261	$ 2,657