Fair Value Measurements (Assets And Liabilities Measured On Recurring Basis) (Details) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	$ 27,332,000	$ 25,509,000
Total Liabilities	17,307,000	15,367,000
Grantor Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in grantor trusts	16,480,000	14,693,000
Deferred compensation plan obligations	16,480,000	14,693,000
Interest Rate Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts, Assets	10,852,000	10,816,000
Interest rate contracts, Liabilities	827,000	674,000
Quoted Prices In Active Markets For Identical Assets And Liabilities (Level1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	16,480,000	14,693,000
Total Liabilities	16,480,000	14,693,000
Quoted Prices In Active Markets For Identical Assets And Liabilities (Level1) [Member] | Grantor Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in grantor trusts	16,480,000	14,693,000
Deferred compensation plan obligations	16,480,000	14,693,000
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	10,852,000	10,816,000
Total Liabilities	827,000	674,000
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate contracts, Assets	10,852,000	10,816,000
Interest rate contracts, Liabilities	827,000	674,000
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	0	0
Total Liabilities	$ 0	$ 0