Schedule of Progression of Liabilities Associated with Restructuring Activities, Combined with Reconciliation to Restructuring and Other Expense (Detail) $ in Thousands	3 Months Ended
	Aug. 31, 2015 USD ($)
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 2,541
Expense	3,069
Payments	(739)
Adjustments	(15)
Ending Balance	4,856
Early Retirement And Severance
Restructuring Cost and Reserve [Line Items]
Beginning Balance	2,170
Expense	3,030
Payments	(686)
Adjustments	(15)
Ending Balance	4,499
Facility Exit And Other Costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance	371
Expense	39
Payments	(53)
Ending Balance	$ 357