Fair Value Measurements (Schedule of Assets and Liabilities Measured at a Fair Value on Recurring Basis) (Details) - Recurring Basis [Member] - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments related to deferred compensation liabilities	$ 822,000	$ 823,000
Deferred compensation liabilities	836,000	824,000
Interest rate swaps asset		136,000
Interest rate swaps liability	21,172,000	7,180,000
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments related to deferred compensation liabilities	822,000	823,000
Deferred compensation liabilities	836,000	824,000
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps asset		136,000
Interest rate swaps liability	$ 21,172,000	$ 7,180,000