Summary of Significant Accounting Policies - Restructuring and Other Exit Costs, Supplemental Information on Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Supplemental Information on Cash Flows
Interest paid	$ 2.1	$ 4.3	$ 8.6
Income taxes paid	23.9	8.2	14.3
Income tax refunds and interest received	$ 3.8	8.3	7.0
Cost of sales and services and Selling, general and administrative
Restructuring and Impairment Costs
Severance and furlough-related costs		$ 9.0	$ 7.1