Fair Value Measurements (Assets And Liabilities Measured On Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value Measurements [Line Items]
Total assets	$ 25,956	$ 25,509
Total liabilities	16,798	15,367
Grantor Trusts [Member]
Fair Value Measurements [Line Items]
Investments in grantor trusts	16,030	14,693
Deferred compensation plan obligations	16,030	14,693
Interest Rate Contracts [Member]
Fair Value Measurements [Line Items]
Interest rate contracts, assets	9,926	10,816
Interest rate contracts, liabilities	768	674
Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member]
Fair Value Measurements [Line Items]
Total assets	16,030	14,693
Total liabilities	16,030	14,693
Quoted Prices In Active Markets For Identical Assets And Liabilities (Level 1) [Member] | Grantor Trusts [Member]
Fair Value Measurements [Line Items]
Investments in grantor trusts	16,030	14,693
Deferred compensation plan obligations	16,030	14,693
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Measurements [Line Items]
Total assets	9,926	10,816
Total liabilities	768	674
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Fair Value Measurements [Line Items]
Interest rate contracts, assets	9,926	10,816
Interest rate contracts, liabilities	768	674
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Measurements [Line Items]
Total assets	0	0
Total liabilities	$ 0	$ 0