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, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (394)	$ 3,504	$ 277	$ 4,454
Commodity Contracts | Cost Of Goods Sold
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	(394)	2,420	282	4,233
Foreign Exchange Contracts | Miscellaneous Income (Expense)
Derivative [Line Items]
Gain (Loss) Recognized in Earnings		$ 1,084	$ (5)	$ 221