Derivative Instruments and Hedging Activities - Schedule of Gain (Loss) Recognized in Earnings for Economic (Non-Designated) Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	12 Months Ended
May 31, 2018	May 31, 2017
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ 6,020	$ 3,196
Commodity Contracts \| Cost of Sales
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	6,284	3,749
Foreign Exchange Contracts \| Miscellaneous Income Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (264)	$ (553)

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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4CC
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

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