Goodwill and Other Long-Lived Assets - Summary of Other Intangible Assets by Class (Detail) - USD ($) $ in Millions	May 31, 2024	May 31, 2023
Other Intangible Assets [Line Items]
Indefinite-lived intangibles assets, Cost	$ 6.5	$ 6.5
Definite-lived intangibles assets, Cost	115.8	115.8
Total intangible assets, Cost	122.3	122.3
Total intangible assets, Accumulated Amortization	45.3	38.9
Definite-lived intangible assets, Accumulated Amortization	45.3	38.9
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	102.8	102.8
Total intangible assets, Accumulated Amortization	39.8	35.0
Non-compete agreements
Other Intangible Assets [Line Items]
Definite-lived intangibles assets, Cost	2.0	2.0
Total intangible assets, Accumulated Amortization	2.0	1.9
Technology / know-how
Other Intangible Assets [Line Items]
Definite-lived intangibles assets, Cost	11.0	11.0
Total intangible assets, Accumulated Amortization	3.5	2.0
In-process research & development
Other Intangible Assets [Line Items]
Indefinite-lived intangibles assets, Cost	$ 1.3	$ 1.3