Schedule of Progression of Liabilities Associated with Restructuring Activities, Combined with Reconciliation to Restructuring and Other Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Restructuring Cost and Reserve [Line Items]
Beginning Balance			$ 2,541
Expense			11,941
Payments			(10,399)
Adjustments			3
Ending Balance	$ 4,086		4,086
Net gain on sale of assets			(6,647)
Restructuring and other expense	702	$ 2,177	5,294	$ 2,765
Early Retirement And Severance
Restructuring Cost and Reserve [Line Items]
Beginning Balance			2,170
Expense			5,365
Payments			(4,639)
Adjustments			26
Ending Balance	2,922		2,922
Facility Exit And Other Costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance			371
Expense			6,576
Payments			(5,760)
Adjustments			(23)
Ending Balance	$ 1,164		$ 1,164