Derivative Instruments - Effects of Cash Flow Hedges Included in Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019
Derivative [Line Items]
Revenue	$ 762,557	$ 856,152	$ 2,155,764	$ 2,119,346
Cost of revenue	655,026	749,580	1,869,708	1,886,397
Interest and foreign exchange	7,562	9,770	33,023	23,411
Sales
Derivative [Line Items]
Amount of gain (loss) on cash flow hedge activity	(485)	(68)	(584)	(735)
Cost of Sales
Derivative [Line Items]
Amount of gain (loss) on cash flow hedge activity	(1,226)	(181)	(1,228)	(771)
Interest and Foreign Exchange
Derivative [Line Items]
Amount of gain (loss) on cash flow hedge activity	$ (783)	$ (143)	$ (1,319)	$ (438)