Goodwill and Other Assets - Summary of Other Intangible Assets by Class (Detail) - USD ($) $ in Millions	May 31, 2025	May 31, 2024
Other Intangible Assets [Line Items]
Indefinite-lived intangibles assets, Cost	$ 5.2	$ 6.5
Definite-lived intangibles assets, Cost	113.0	115.8
Total intangible assets, Cost	118.2	122.3
Total intangible assets, Accumulated Amortization	50.3	45.3
Definite-lived intangible assets, Accumulated Amortization	50.3	45.3
Trademarks
Other Intangible Assets [Line Items]
Indefinite-lived intangibles assets, Cost	5.2	5.2
Customer relationships
Other Intangible Assets [Line Items]
Definite-lived intangibles assets, Cost	100.0	102.8
Total intangible assets, Accumulated Amortization	43.5	39.8
Non-compete agreements
Other Intangible Assets [Line Items]
Definite-lived intangibles assets, Cost	2.0	2.0
Total intangible assets, Accumulated Amortization	2.0	2.0
Technology / know-how
Other Intangible Assets [Line Items]
Definite-lived intangibles assets, Cost	11.0	11.0
Total intangible assets, Accumulated Amortization	4.8	3.5
In-process research & development
Other Intangible Assets [Line Items]
Indefinite-lived intangibles assets, Cost	$ 1.3	$ 1.3