Retirement-Related Benefit Plans' Impact on Income Before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2020	Nov. 30, 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	$ 22,260	$ 19,712
Interest cost	3,806	5,104	7,612	10,208
Expected return on plan assets	(8,279)	(8,573)	(16,558)	(17,146)
Prior service cost (credit)	2	2	4	4
Net actuarial (gains) losses recognized	7,501	4,629	15,002	9,258
Net Periodic Benefit (Credit) Cost	14,160	11,018	28,320	22,036
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	2,812	2,782
Interest cost	1,122	1,193	2,244	2,386
Expected return on plan assets	(1,607)	(1,834)	(3,214)	(3,668)
Prior service cost (credit)	(35)	(9)	(70)	(18)
Net actuarial (gains) losses recognized	526	523	1,052	1,046
Net Periodic Benefit (Credit) Cost	1,412	1,264	2,824	2,528
Postretirement Benefits | U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	19	37	38	74
Prior service cost (credit)	(42)	(55)	(84)	(110)
Net actuarial (gains) losses recognized	10	(16)	20	(32)
Net Periodic Benefit (Credit) Cost	(13)	(34)	(26)	(68)
Postretirement Benefits | Non-U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	431	429	862	858
Interest cost	283	282	566	564
Net actuarial (gains) losses recognized	130	158	260	316
Net Periodic Benefit (Credit) Cost	$ 844	$ 869	$ 1,688	$ 1,738