Summary of Significant Accounting Policies - Intangibles assets (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2021
Amortizable intangible assets:
Gross carrying amount	$ 62.5
Accumulated Amortization	(6.0)	$ (9.1)
Net carrying amount	56.5
Unamortized intangible assets:
Trademarks	7.2	1.1
Intangible assets, gross	69.7	12.4
Intangible assets, net	63.7	3.3
Amortization expense	1.3	1.1	$ 1.8
Estimated aggregate amortization expense for intangible assets in each of the next five fiscal years
2024	4.4
2025	4.4
2026	4.4
2027	4.4
2028	4.4
Customer relationships
Amortizable intangible assets:
Gross carrying amount	40.5	11.3
Accumulated Amortization	(5.8)	(9.1)
Net carrying amount	34.7	$ 2.2
Developed technology
Amortizable intangible assets:
Gross carrying amount	22.0
Accumulated Amortization	(0.2)
Net carrying amount	$ 21.8
Unamortized intangible assets:
Useful life	20 years
Minimum | Customer relationships
Unamortized intangible assets:
Useful life	12 years
Maximum | Customer relationships
Unamortized intangible assets:
Useful life	20 years