Schedule of Derivatives Designated as Cash Flow Hedging Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended
Aug. 31, 2017	Aug. 31, 2016
Derivative [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	$ 6,798	$ 733
Gain (Loss) Reclassified from Accumulated OCI (Effective Portion)	3,805	(355)
Commodity Contracts
Derivative [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	3,734	769
Commodity Contracts \| Cost of Goods Sold
Derivative [Line Items]
Gain (Loss) Reclassified from Accumulated OCI (Effective Portion)	4,168	(252)
Interest Rate Contracts
Derivative [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	3,064	(36)
Interest Rate Contracts \| Interest Expense
Derivative [Line Items]
Gain (Loss) Reclassified from Accumulated OCI (Effective Portion)	$ (363)	$ (103)

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and 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 (c)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624177-113959

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- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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