Schedule of Gain (Loss) Recognized in Earnings for Economic (Non-Designated) Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended
Aug. 31, 2016	Aug. 31, 2015
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ 2,842	$ (2,755)
Commodity Contracts \| Cost of Goods Sold
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	2,908	$ (2,755)
Foreign Currency Contracts \| Miscellaneous Income (Expense)
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (66)

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

Name:	us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration