Derivative Instruments and Hedging Activities - Schedule of Gain (Loss) Recognized in Earnings for Economic (Non-Designated) Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (1,920)	$ (67)	$ (5,623)	$ 2,059
Commodity Contracts \| Cost of Sales
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	(737)	(86)	(2,934)	2,248
Foreign Currency Exchange Contracts \| Miscellaneous Income, Net
Derivative [Line Items]
Gain (Loss) Recognized in Earnings	$ (1,183)	$ 19	$ (2,689)	$ (189)

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