Derivative Instruments And Hedging Activities (Schedule Of Summary Of Derivative Hedges) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Nov. 30, 2011
Derivative [Line Items]
Maturity Date, lower limit	January 2012
Maturity Date, upper limit	December 2012
Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedges [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional Amount	$ 100,000
Maturity Date	December 2014
Derivatives Not Designated As Hedging Instruments [Member] | Commodity Contracts [Member]
Derivative [Line Items]
Notional Amount	13,710
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Currency Contracts [Member]
Derivative [Line Items]
Notional Amount	$ 76,670
Maturity Date	July 2012