Retirement-Related Benefit Plans' Impact on Income Before Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2012	Nov. 30, 2011
Pension Benefits, U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 6,488	$ 4,976	$ 12,976	$ 9,953
Interest cost	4,060	3,827	8,120	7,654
Expected return on plan assets	(4,358)	(4,354)	(8,716)	(8,708)
Amortization of:
Prior service cost(credit)	87	88	174	176
Net actuarial (gains) losses recognized	4,222	2,128	8,444	4,255
Net Periodic Benefit Cost	10,499	6,665	20,998	13,330
Pension Benefits, Non-U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	1,050	966	2,100	1,931
Interest cost	1,769	2,041	3,538	4,081
Expected return on plan assets	(1,846)	(2,037)	(3,692)	(4,073)
Amortization of:
Prior service cost(credit)	2	3	4	6
Net actuarial (gains) losses recognized	692	559	1,384	1,119
Net Periodic Benefit Cost	1,667	1,532	3,334	3,064
Postretirement Benefits, U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	88	104	176	208
Amortization of:
Prior service cost(credit)	(22)	(21)	(44)	(43)
Net actuarial (gains) losses recognized	4	(15)	8	(29)
Net Periodic Benefit Cost	70	68	140	136
Postretirement Benefits, Non-U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	288	192	576	384
Interest cost	289	249	578	499
Amortization of:
Net actuarial (gains) losses recognized	114	19	228	37
Net Periodic Benefit Cost	$ 691	$ 460	$ 1,382	$ 920