Derivative Financial Instruments (Schedule Of Derivatives, Location In Consolidated Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Derivatives, Fair Value [Line Items]
Total Derivatives	$ 70,454	$ 41,843
Derivatives Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivatives Designated as Hedging, Liability	69,943	40,285
Derivatives Not Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivatives Not Designated as Hedging Instruments, Asset	606	943
Derivatives Not Designated as Hedging Instruments, Liability	1,117	2,501
Interest Rate Swap Contracts [Member] | Derivatives Designated As Hedging Instruments [Member] | Current Portion Of Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives Designated as Hedging, Liability	22,520	21,083
Interest Rate Swap Contracts [Member] | Derivatives Designated As Hedging Instruments [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives Designated as Hedging, Liability	47,423	19,202
Interest Rate Swap Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Prepaid Expenses, Deferred Costs, And Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives Not Designated as Hedging Instruments, Asset		109
Interest Rate Swap Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Prepaid Expenses, Deferred Costs, And Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives Not Designated as Hedging Instruments, Asset	606	834
Interest Rate Swap Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Current Portion Of Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives Not Designated as Hedging Instruments, Liability	1,117	1,872
Interest Rate Swap Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Other Long-Term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives Not Designated as Hedging Instruments, Liability		$ 629