Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	May 31, 2020	May 31, 2019
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	$ 1,755,190	$ 1,662,859
Less: allowance for depreciation and amortization	905,504	843,648
Property, plant and equipment, net	849,686	819,211
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	85,860	88,638
Building And Leasehold Improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	469,483	459,542
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	$ 1,199,847	$ 1,114,679