Fair Value Measurements (Schedule Of Assets And Liabilities Measured At A Fair Value On Recurring Basis) (Details) - Recurring Basis [Member] - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments related to deferred compensation liabilities	$ 607,000	$ 539,000
Deferred compensation liabilities	604,000	529,000
Interest rate swaps liability	13,618,000	3,945,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments related to deferred compensation liabilities	607,000	539,000
Deferred compensation liabilities	604,000	529,000
Interest rate swaps liability
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments related to deferred compensation liabilities
Deferred compensation liabilities
Interest rate swaps liability	13,618,000	3,945,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments related to deferred compensation liabilities
Deferred compensation liabilities
Interest rate swaps liability