Derivative Instruments and Hedging Activities - Schedule of Derivatives Designated as Cash Flow Hedging Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended
Aug. 31, 2018	Aug. 31, 2017
Derivative [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	$ (31)	$ 6,798
Gain (Loss) Reclassified from AOCI (Effective Portion)	2,496	3,805
Commodity Contracts
Derivative [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	(31)	3,734
Commodity Contracts \| Cost of Sales
Derivative [Line Items]
Gain (Loss) Reclassified from AOCI (Effective Portion)	2,543	4,168
Interest Rate Contracts
Derivative [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)		3,064
Interest Rate Contracts \| Interest Expense
Derivative [Line Items]
Gain (Loss) Reclassified from AOCI (Effective Portion)	$ (47)	$ (363)

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e637-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109978405&loc=d3e80720-113993

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration