Retirement-Related Benefit Plans' Impact on Income Before Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 29, 2012	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011
Pension Benefits, U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4,976	$ 4,238	$ 14,929	$ 12,717
Interest cost	3,826	3,435	11,480	10,304
Expected return on plan assets	(4,354)	(3,139)	(13,062)	(9,418)
Amortization of:
Prior service cost	88	90	264	269
Net actuarial (gains) losses recognized	2,127	1,980	6,382	5,939
Net Periodic Benefit Cost	6,663	6,604	19,993	19,811
Pension Benefits, Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	965	830	2,896	2,491
Interest cost	2,040	1,782	6,121	5,347
Expected return on plan assets	(2,036)	(1,655)	(6,109)	(4,966)
Amortization of:
Prior service cost	2	3	8	8
Net actuarial (gains) losses recognized	560	584	1,679	1,754
Net Periodic Benefit Cost	1,531	1,544	4,595	4,634
Postretirement Benefits, U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost		2		4
Interest cost	104	110	312	330
Amortization of:
Prior service cost	(22)	(22)	(65)	(65)
Net actuarial (gains) losses recognized	(14)	(48)	(43)	(143)
Net Periodic Benefit Cost	68	42	204	126
Postretirement Benefits, Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	192	170	576	509
Interest cost	250	213	749	639
Amortization of:
Net actuarial (gains) losses recognized	18	21	55	62
Net Periodic Benefit Cost	$ 460	$ 404	$ 1,380	$ 1,210