Fair Value (Schedule Of Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) (USD $) In Thousands	Aug. 31, 2011	May 31, 2011
Assets	$ 489
Liabilities	12,921	12,972
Commodity Contracts [Member]
Assets	11	1,138
Liabilities	416
Commodity Contracts [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets	11	1,138
Liabilities	416
Foreign Currency Contracts [Member]
Assets	478
Liabilities		573
Foreign Currency Contracts [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets	478
Liabilities		573
Interest Rate Contracts [Member]
Liabilities	12,505	12,399
Interest Rate Contracts [Member] | Significant Other Observable Inputs (Level 2) [Member]
Liabilities	12,505	12,399
Significant Other Observable Inputs (Level 2) [Member]
Assets	489
Liabilities	$ 12,921	$ 12,972