Employee Benefit Plans - Schedule of changes in fair value level 3 assets (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2024	May 31, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 3.3	$ 4.2
Actual Return on Plan Assets:
Relating to assets still held at year-end	(0.1)	(0.9)
Relating to assets sold during the year	0.0	0.0
Purchases, sales and settlements, net	0.0	0.0
Transfers in and/or out of Level 3	0.0	0.0
Foreign currency translation	(0.0)	(0.0)
Ending Balance	$ 3.2	$ 3.3