Accumulated Other Comprehensive Loss - Amounts Reclassified out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest and foreign exchange	$ 7,029	$ 5,673	$ 14,049	$ 7,397
Total before tax	(53,841)	(75,847)	(108,263)	(146,783)
Income tax benefit (expense)	11,301	(24,858)	(6,834)	(45,244)
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	(440)	3,587	(784)	4,068
Income tax benefit (expense)	103	(759)	119	(917)
Net of tax	(337)	2,828	(665)	3,151
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	(546)	3,299	(1,057)	3,442
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	$ 106	$ 288	$ 273	$ 626