Schedule of Gain (Loss) Recognized in Earnings for Economic (Non-Designated) Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ 220	$ (4,105)	$ (7,855)	$ (6,479)
Commodity Contracts | Cost of Goods Sold
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	173	$ (4,105)	(7,972)	(6,522)
Foreign Currency Contracts | Miscellaneous Income (Expense)
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ 47		$ 117	$ 43