Schedule of Progression of Liabilities Created as Part of Transformation Plan, Combined with Reconciliation to Restructuring and Other Expense (Income) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Restructuring Cost and Reserve [Line Items]
Beginning Balance			$ 6,229
Expense/ (Income)			7,854
Payments			(5,853)
Adjustments			(207)
Ending Balance	8,023		8,023
Net gain on sale of assets			(10,587)
Less: joint venture transactions	(120)	(253)	(1,048)	1,188
Restructuring and other expense	1,398	146	(3,781)	1,811
Early Retirement And Severance
Restructuring Cost and Reserve [Line Items]
Beginning Balance			5,029
Expense/ (Income)			5,672
Payments			(3,331)
Adjustments			(81)
Ending Balance	7,289		7,289
Facility Exit And Other Costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance			1,200
Expense/ (Income)			2,182
Payments			(2,522)
Adjustments			(126)
Ending Balance	$ 734		$ 734