Changes in Accrued Restructuring Balances (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014
Restructuring Cost and Reserve [Line Items]
Beginning balance	$ 2,463
Cash payments	(618)
Noncash and foreign exchange impacts	(49)
Ending balance	1,796
Employee Severance
Restructuring Cost and Reserve [Line Items]
Beginning balance	2,082
Cash payments	(492)
Noncash and foreign exchange impacts	(35)
Ending balance	1,555
Other
Restructuring Cost and Reserve [Line Items]
Beginning balance	381
Cash payments	(126)
Noncash and foreign exchange impacts	(14)
Ending balance	$ 241