Changes in Accrued Restructuring Balances (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Feb. 28, 2014	Nov. 30, 2013	Aug. 31, 2013
Restructuring Cost and Reserve [Line Items]
Balance at May 31, 2013	$ 10,004	$ 16,792	$ 17,782
Charge to expense	(371)		128
Cash payments	(1,155)	(7,121)	(1,416)
Noncash and foreign exchange impacts	102	333	298
Balance at August 31, 2013	8,580	10,004	16,792
Long-Lived Asset Charges
Restructuring Cost and Reserve [Line Items]
Balance at May 31, 2013	4,988	4,852	4,729
Noncash and foreign exchange impacts	77	136	123
Balance at August 31, 2013	5,065	4,988	4,852
Employee Severance
Restructuring Cost and Reserve [Line Items]
Balance at May 31, 2013	4,597	11,533	12,656
Charge to expense	(371)		128
Cash payments	(1,116)	(7,121)	(1,416)
Noncash and foreign exchange impacts	19	185	165
Balance at August 31, 2013	3,129	4,597	11,533
Site Preparation and Equipment Relocation
Restructuring Cost and Reserve [Line Items]
Balance at May 31, 2013	419	407	397
Cash payments	(39)
Noncash and foreign exchange impacts	6	12	10
Balance at August 31, 2013	$ 386	$ 419	$ 407