Accumulated Other Comprehensive Loss - Amounts Reclassified out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2023	May 31, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest and foreign exchange	$ 22.8	$ 14.9	$ 64.0	$ 39.3
Total before tax	(27.9)	(4.7)	(49.3)	(17.3)
Income tax (benefit) expense	3.6	1.1	11.7	2.9
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	(3.9)	2.2	(7.0)	5.2
Income tax (benefit) expense	1.2	(0.7)	2.2	(1.4)
Net of tax	(2.7)	1.5	(4.8)	3.8
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	(0.5)	0.5	(0.2)	0.9
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	$ (3.4)	$ 1.7	$ (6.8)	$ 4.3