Derivative Financial Instruments And Fair Value Measurements (Summary Of Derivative Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Interest Rate Swap Contracts [Member]
Derivatives, Fair Value [Line Items]
Liability, Fair Value	$ 93,384	$ 102,297
Interest Rate Swap Contracts [Member] | Level 1 [Member]
Derivatives, Fair Value [Line Items]
Liability, Fair Value
Interest Rate Swap Contracts [Member] | Level 2 [Member]
Derivatives, Fair Value [Line Items]
Liability, Fair Value	93,384	102,297
Interest Rate Swap Contracts [Member] | Level 3 [Member]
Derivatives, Fair Value [Line Items]
Liability, Fair Value
Commodities Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset, Fair Value	7,489	2,099
Liability, Fair Value	8,958	3,876
Commodities Contracts [Member] | Level 1 [Member]
Derivatives, Fair Value [Line Items]
Asset, Fair Value
Liability, Fair Value
Commodities Contracts [Member] | Level 2 [Member]
Derivatives, Fair Value [Line Items]
Asset, Fair Value	7,489	2,099
Liability, Fair Value	8,958	3,876
Commodities Contracts [Member] | Level 3 [Member]
Derivatives, Fair Value [Line Items]
Asset, Fair Value
Liability, Fair Value
Foreign Currency Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset, Fair Value	196	411
Liability, Fair Value	2,939
Foreign Currency Contracts [Member] | Level 1 [Member]
Derivatives, Fair Value [Line Items]
Asset, Fair Value
Liability, Fair Value
Foreign Currency Contracts [Member] | Level 2 [Member]
Derivatives, Fair Value [Line Items]
Asset, Fair Value	196	411
Liability, Fair Value	2,939
Foreign Currency Contracts [Member] | Level 3 [Member]
Derivatives, Fair Value [Line Items]
Asset, Fair Value
Liability, Fair Value