Schedule of Summary of Derivative Hedges (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Nov. 30, 2014
Cash Flow Hedges | Commodity Contracts
Derivative [Line Items]
Notional Amount	57,368
Cash Flow Hedges | Commodity Contracts | Minimum
Derivative [Line Items]
Maturity Date	2014-12
Cash Flow Hedges | Commodity Contracts | Maximum
Derivative [Line Items]
Maturity Date	2016-07
Cash Flow Hedges | Interest Rate Contracts
Derivative [Line Items]
Notional Amount	120,000
Cash Flow Hedges | Interest Rate Contracts | Minimum
Derivative [Line Items]
Maturity Date	2014-12
Cash Flow Hedges | Interest Rate Contracts | Maximum
Derivative [Line Items]
Maturity Date	2019-09
Cash Flow Hedges | Foreign Currency Contracts
Derivative [Line Items]
Notional Amount	11,168
Cash Flow Hedges | Foreign Currency Contracts | Minimum
Derivative [Line Items]
Maturity Date	2014-12
Cash Flow Hedges | Foreign Currency Contracts | Maximum
Derivative [Line Items]
Maturity Date	2015-06
Derivatives Not Designated As Hedging Instruments | Commodity Contracts
Derivative [Line Items]
Notional Amount	57,607
Derivatives Not Designated As Hedging Instruments | Commodity Contracts | Minimum
Derivative [Line Items]
Maturity Date	2014-12
Derivatives Not Designated As Hedging Instruments | Commodity Contracts | Maximum
Derivative [Line Items]
Maturity Date	2016-06