Other Assets and Deferred Charges, Net (Schedule of Future Charges of Unamortized Balances of Deferred Lease Origination Costs and Deferred Financing Costs) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs And Other Assets [Line Items]
Lease origination costs, 2021	$ 2,436,000
Lease origination costs, 2022	2,094,000
Lease origination costs, 2023	1,805,000
Lease origination costs, 2024	1,467,000
Lease origination costs, 2025	1,196,000
Lease origination costs, thereafter	13,333,000
Lease origination costs	22,331,000	$ 19,947,000
Financing costs	2,002,000	2,769,000
Unsecured Revolving Credit Facility [Member]
Deferred Costs And Other Assets [Line Items]
Financing costs, 2021	623,000
Financing costs	$ 623,000	$ 1,021,000