Summary of Significant Accounting Policies (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impairment of real estate			$ 0
Allowance for doubtful accounts	$ 286,000		286,000		$ 161,000
Rental revenue adjustment	83,000	$ 59,000	131,000	$ 119,000
Rental revenue adjustment due to COVID-19	20,000		$ 33,000
Uncertain tax position to be recognized based on maximum cumulative probability percentage			50.00%
Operating loss carry-forwards	326,000		$ 326,000
Deferred tax liabilities	101,000	96,000	101,000	96,000
Total lease liabilities	14,000		14,000		7,000
Operating lease payments	$ 14,000		$ 14,000
Operating lease, weighted average discount rate, percent	4.50%		4.50%
Operating lease right of use assets	$ 14,000		$ 14,000		$ 7
Rental revenues	2,185,000	3,254,000	4,522,000	6,519,000
Recoveries	$ 334,000	$ 613,000	$ 614,000	$ 1,250,000
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total lease liabilities						$ 21,000
Operating lease payments						$ 22,000
Operating lease, weighted average discount rate, percent						4.50%
Operating lease right of use assets						$ 21,000
Building and Building Improvements [Member] | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives			5 years
Building and Building Improvements [Member] | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives			39 years