Fair Value Measurements (Assets And Liabilities Measured On Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fair Value Measurements [Line Items]
Total Assets	$ 26,546	$ 25,509
Total Liabilities	16,475	15,367
Quoted Prices In Active Markets For Identical Assets And Liabilities (Level1) [Member]
Fair Value Measurements [Line Items]
Total Assets	15,692	14,693
Total Liabilities	15,692	14,693
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Measurements [Line Items]
Total Assets	10,854	10,816
Total Liabilities	783	674
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Measurements [Line Items]
Total Assets	0	0
Total Liabilities	0	0
Grantor Trusts [Member]
Fair Value Measurements [Line Items]
Investments in grantor trusts	15,692	14,693
Deferred compensation plan obligations	15,692	14,693
Grantor Trusts [Member] | Quoted Prices In Active Markets For Identical Assets And Liabilities (Level1) [Member]
Fair Value Measurements [Line Items]
Investments in grantor trusts	15,692	14,693
Deferred compensation plan obligations	15,692	14,693
Interest Rate Contracts [Member]
Fair Value Measurements [Line Items]
Interest rate contracts, Assets	10,854	10,816
Interest rate contracts, Liabilities	783	674
Interest Rate Contracts [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value Measurements [Line Items]
Interest rate contracts, Assets	10,854	10,816
Interest rate contracts, Liabilities	$ 783	$ 674