Leases (Components of Lease Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Leases [Abstract]
Fixed payment operating lease expense	$ 27.2	$ 34.6	$ 38.2
Variable payment operating lease expense	$ 6.9	8.3	8.6
Short-term lease expense		$ 0.1	$ 0.2