Leases - Lease Expense (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2024	May 31, 2023	May 31, 2022
Leases [Abstract]
Operating lease expense	$ 29.7	$ 26.6	$ 25.9
Depreciation of leased assets	2.1	2.1	2.2
Accretion of lease liabilities	0.3	0.3	0.4
Total lease expense	$ 32.1	$ 29.0	$ 28.5