Employee Pension Plans - Components of Net Periodic Pension for Defined Benefit Pension and Other Postretirement Benefit Plans (Detail) - USD ($) $ in Thousands		12 Months Ended
		May 31, 2022	May 31, 2021	May 31, 2020
Compensation And Retirement Disclosure [Abstract]
Interest cost		$ 2,621	$ 1,205	$ 1,352
Return on plan assets		(4,473)	(4,289)	(1,928)
Net amortization and deferral costs		546	3,058	628
Settlement cost	[1]	1,357	18
Defined contribution plans		18,036	17,562	16,495
Net periodic benefit cost	[2]	$ 18,087	$ 17,554	$ 16,547

[1] Relates to the settlement of certain participant balances within the Gerstenslager Plan.

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