Activity Related to Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2021
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, beginning balance	$ 5.7	$ 7.5	$ 9.0
Additions for tax positions of prior years	0.1
Reductions for tax positions of prior years	(2.8)	(1.7)	(1.8)
Foreign currency translation			0.3
Foreign currency translation	(0.1)	(0.1)
Unrecognized tax benefits, ending balance	$ 2.9	$ 5.7	$ 7.5