Note 12 - Segments - Operating Income by Segment (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Rental, fees and other income	$ 4,121,491	$ 4,573,141
Property and related expenses	(1,574,990)	(1,583,473)
General and administrative expenses	(1,964,620)	(1,583,691)
Depreciation and amortization	(1,333,574)	(1,339,225)
Interest expense	(867,767)	(1,017,713)
Other income (expense), net	742,117	73,605
Income tax expense	(148,453)	(265,239)
Gain on sale of real estate	417,337	1,522,785
Net income (loss)	(608,459)	380,190
Operating Segments [Member]
Net operating income, as defined	2,546,501	2,989,668
Office/Industrial Properties [Member] | Operating Segments [Member]
Rental, fees and other income	2,861,998	3,122,888
Property and related expenses	(1,460,690)	(1,356,534)
Net operating income, as defined	1,401,308	1,766,354
Model Home Properties [Member] | Operating Segments [Member]
Rental, fees and other income	855,120	710,328
Property and related expenses	(30,996)	(27,768)
Net operating income, as defined	824,124	682,560
Retail Properties [Member] | Operating Segments [Member]
Rental, fees and other income	458,867	753,341
Property and related expenses	(137,798)	(212,587)
Net operating income, as defined	$ 321,069	$ 540,754