Employee Retirement Plans - Summary of Defined Benefit Plan's Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions		May 31, 2024	May 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value		$ 53.5	$ 54.9
Quoted Prices In Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value		45.2	46.1
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value		4.3	3.9
Cash and Cash Equivalents | Quoted Prices In Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value		4.3	3.9
Fixed-Income Funds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value		24.7	22.1
Fixed-Income Funds | Quoted Prices In Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value		24.7	22.1
Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value		16.2	20.1
Equity Funds | Quoted Prices In Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value		16.2	20.1
Hedge Funds | Commingled Fund Investments Measured at Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit plan assets fair value	[1]	$ 8.3	$ 8.8

[1] Investments that are measured at fair value using the net asset value per share (or its equivalent) as a practical expedient have not been categorized in the fair value hierarchy.