Schedule of Gain (Loss) Recognized in Earnings for Economic (Non-Designated) Derivative Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (2,578)	$ (394)	$ (2,374)	$ 277
Commodity Contracts | Cost Of Goods Sold
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	(2,360)	(394)	(2,417)	282
Foreign Currency Contracts | Miscellaneous Income (Expense)
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (218)		$ 43	$ (5)