Income Taxes - Components of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Millions	12 Months Ended
	May 31, 2025	May 31, 2024	May 31, 2023
Current
Federal	$ 24.6	$ 25.3	$ 26.9
State and local	3.3	6.3	4.2
Foreign	4.0	13.4	7.6
Subtotal	31.9	45.0	38.7
Deferred
Federal	0.4	4.7	(8.6)
State and local	0.2	(0.8)	(0.6)
Foreign	(3.7)	(2.8)	(0.5)
Subtotal	(3.1)	1.1	(9.7)
Total	$ 28.8	$ 46.1	$ 29.0