Retirement-Related Benefit Plans' Impact on Income Before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017
Pension Benefits | U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 9,465	$ 9,401	$ 28,395	$ 28,203
Interest cost	4,379	4,331	13,137	12,993
Expected return on plan assets	(8,086)	(6,252)	(24,258)	(18,756)
Amortization of Prior service cost (credit)	29	54	87	162
Amortization of Net actuarial losses recognized	3,618	5,540	10,854	16,620
Net Periodic Benefit (Credit) Cost	9,405	13,074	28,215	39,222
Pension Benefits | Non-U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	1,175	1,127	3,525	3,381
Interest cost	1,145	1,224	3,435	3,672
Expected return on plan assets	(1,978)	(1,886)	(5,934)	(5,658)
Amortization of Prior service cost (credit)	(6)		(18)
Amortization of Net actuarial losses recognized	451	573	1,353	1,719
Net Periodic Benefit (Credit) Cost	787	1,038	2,361	3,114
Postretirement Benefits | U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	43	57	129	171
Amortization of Prior service cost (credit)	(55)	(58)	(165)	(174)
Amortization of Net actuarial losses recognized	6		18
Net Periodic Benefit (Credit) Cost	(6)	(1)	(18)	(3)
Postretirement Benefits | Non-U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	311	284	933	852
Interest cost	224	222	672	666
Amortization of Net actuarial losses recognized	79	60	237	180
Net Periodic Benefit (Credit) Cost	$ 614	$ 566	$ 1,842	$ 1,698