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. 28, 2017	Feb. 29, 2016	Feb. 28, 2017	Feb. 29, 2016
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ 86	$ 220	$ 4,332	$ (7,855)
Commodity Contracts | Cost of Goods Sold
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	258	173	5,169	(7,972)
Foreign Currency Contracts | Miscellaneous Income, Net
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (172)	$ 47	$ (837)	$ 117