Employee Pension Plans - Components of Net Periodic Pension for Defined Benefit Pension and Other Postretirement Benefit Plans (Parenthetical) (Details) - USD ($) $ in Thousands		12 Months Ended
		May 31, 2022	May 31, 2021	May 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	[1]	$ 18,087	$ 17,554	$ 16,547
Tempel Steel Company
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		$ 85

[1] During fiscal year 2022, we also incurred $85 (in thousands) in net periodic benefit cost related to the Tempel Steel Company Postretirement Benefit Plan.