Derivative Instruments - Fair Values of Derivative Instruments (Detail) - USD ($) $ in Millions	May 31, 2022	Aug. 31, 2021
Designated as Hedging Instrument | Accounts Payable and Accrued Liabilities
Derivatives Fair Value [Line Items]
Liability Derivatives	$ 2.9	$ 10.3
Designated as Hedging Instrument | Accounts Receivable
Derivatives Fair Value [Line Items]
Asset Derivatives	13.6	0.1
Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivatives Fair Value [Line Items]
Liability Derivatives	2.3	0.3
Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Receivable
Derivatives Fair Value [Line Items]
Asset Derivatives	1.2	0.1
Designated as Hedging Instrument | Interest rate swap contracts | Accounts Payable and Accrued Liabilities
Derivatives Fair Value [Line Items]
Liability Derivatives	0.6	10.0
Designated as Hedging Instrument | Interest rate swap contracts | Accounts Receivable
Derivatives Fair Value [Line Items]
Asset Derivatives	$ 12.4
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Accounts Payable and Accrued Liabilities
Derivatives Fair Value [Line Items]
Liability Derivatives		$ 0.1