Retirement-Related Benefit Plans' Impact on Income Before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2020	Aug. 31, 2019
Pension Benefits | U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 11,130	$ 9,856
Interest cost	3,806	5,104
Expected return on plan assets	(8,279)	(8,573)
Prior service cost (credit)	2	2
Net actuarial (gains) losses recognized	7,501	4,629
Net Periodic Benefit (Credit) Cost	14,160	11,018
Pension Benefits | Non-U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	1,406	1,391
Interest cost	1,122	1,193
Expected return on plan assets	(1,607)	(1,834)
Prior service cost (credit)	(35)	(9)
Net actuarial (gains) losses recognized	526	523
Net Periodic Benefit (Credit) Cost	1,412	1,264
Postretirement Benefits | U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	19	37
Prior service cost (credit)	(42)	(55)
Net actuarial (gains) losses recognized	10	(16)
Net Periodic Benefit (Credit) Cost	(13)	(34)
Postretirement Benefits | Non-U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	431	429
Interest cost	283	282
Net actuarial (gains) losses recognized	130	158
Net Periodic Benefit (Credit) Cost	$ 844	$ 869