Derivative Instruments and Hedging Activities - Schedule of Derivatives Designated as Cash Flow Hedging 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 OCI (Effective Portion)	$ (4,499)	$ 2,114	$ (4,530)	$ 8,912
Gain (Loss) Reclassified from AOCI (Effective Portion)	1,567	5,609	4,063	9,414
Commodity Contracts
Derivative [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	(4,499)	2,080	(4,530)	5,814
Commodity Contracts | Cost of Sales
Derivative [Line Items]
Gain (Loss) Reclassified from AOCI (Effective Portion)	1,565	5,637	4,108	9,805
Interest Rate Contracts
Derivative [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)		34		3,098
Interest Rate Contracts | Interest Expense
Derivative [Line Items]
Gain (Loss) Reclassified from AOCI (Effective Portion)	(34)	$ (28)	(81)	$ (391)
Foreign Currency Exchange Contracts | Miscellaneous Income, Net
Derivative [Line Items]
Gain (Loss) Reclassified from AOCI (Effective Portion)	$ 36		$ 36