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, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Pension Benefits, U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 6,764	$ 6,488	$ 13,528	$ 12,976
Interest cost	4,510	4,060	9,020	8,120
Expected return on plan assets	(5,191)	(4,358)	(10,381)	(8,716)
Amortization of:
Prior service cost (credit)	84	87	167	174
Net actuarial (gains) losses recognized	3,305	4,222	6,611	8,444
Net Periodic Benefit Cost	9,472	10,499	18,945	20,998
Pension Benefits, Non-U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	1,109	1,050	2,218	2,100
Interest cost	1,799	1,769	3,599	3,538
Expected return on plan assets	(2,096)	(1,846)	(4,191)	(3,692)
Amortization of:
Prior service cost (credit)	1	2	2	4
Net actuarial (gains) losses recognized	624	692	1,247	1,384
Net Periodic Benefit Cost	1,437	1,667	2,875	3,334
Postretirement Benefits, U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	81	88	162	176
Amortization of:
Prior service cost (credit)	(22)	(22)	(44)	(44)
Net actuarial (gains) losses recognized	(29)	4	(58)	8
Net Periodic Benefit Cost	30	70	60	140
Postretirement Benefits, Non-U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	327	288	654	576
Interest cost	317	289	634	578
Amortization of:
Net actuarial (gains) losses recognized	134	114	267	228
Net Periodic Benefit Cost	$ 778	$ 691	$ 1,555	$ 1,382