Derivative Financial Instruments and Hedging Activities - Schedule of Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	May 31, 2024	May 31, 2023
Derivative [Line Items]
Asset Derivatives at Fair Value	$ 3.6	$ 2.3
Liability Derivatives at Fair Value	4.4	9.8
Derivatives Designated As Hedging Instruments | Commodity Contracts
Derivative [Line Items]
Asset Derivatives at Fair Value	0.2	0.1
Liability Derivatives at Fair Value	1.9	2.8
Derivatives Designated As Hedging Instruments | Commodity Contracts | Other Liabilities
Derivative [Line Items]
Liability Derivatives at Fair Value		0.1
Derivatives Designated As Hedging Instruments | Commodity Contracts | Receivables
Derivative [Line Items]
Asset Derivatives at Fair Value	0.2
Derivatives Designated As Hedging Instruments | Commodity Contracts | Other Assets
Derivative [Line Items]
Asset Derivatives at Fair Value		0.1
Derivatives Not Designated As Hedging Instruments | Commodity Contracts
Derivative [Line Items]
Asset Derivatives at Fair Value	3.4	2.2
Liability Derivatives at Fair Value	2.5	7.0
Derivatives Not Designated As Hedging Instruments | Commodity Contracts | Receivables
Derivative [Line Items]
Asset Derivatives at Fair Value	3.4	2.2
Accounts Payable | Derivatives Designated As Hedging Instruments | Commodity Contracts
Derivative [Line Items]
Liability Derivatives at Fair Value	1.9	2.7
Accounts Payable | Derivatives Not Designated As Hedging Instruments | Commodity Contracts
Derivative [Line Items]
Liability Derivatives at Fair Value	$ 2.5	$ 7.0