Relationship between Plans Benefit Obligations and Assets (Detail) - Pension Benefits - USD ($) $ in Thousands	May 31, 2020	May 31, 2019
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Plans with projected benefit obligations in excess of plan assets, benefit obligation	$ 762,739	$ 660,277
Plans with accumulated benefit obligations in excess of plan assets, benefit obligation	662,197	553,392
Plans with projected benefit obligations in excess of plan assets, plan asset	516,550	496,865
Plans with accumulated benefit obligations in excess of plan assets, plan asset	516,550	496,865
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Plans with projected benefit obligations in excess of plan assets, benefit obligation	163,589	162,824
Plans with accumulated benefit obligations in excess of plan assets, benefit obligation	150,478	149,390
Plans with assets in excess of projected benefit obligations	46,689	43,143
Plans with assets in excess of accumulated benefit obligations	46,689	43,143
Plans with projected benefit obligations in excess of plan assets, plan asset	134,791	134,921
Plans with accumulated benefit obligations in excess of plan assets, plan asset	134,598	134,921
Plans with assets in excess of projected benefit obligations, plan asset	60,083	52,191
Plans with assets in excess of accumulated benefit obligations, plan asset	$ 60,276	$ 52,191