Note 3 - Real Estate - (Details Textual)			6 Months Ended
	Jul. 02, 2020 USD ($) shares	Jan. 10, 2020 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($) property
2020 Real Estate Acquisitions [Member] | Cromwell Field Shopping Center [Member]
Business Acquisition [Line Items]
Business acquisition amount for fee simple interest in land		$ 2,300,000
Business acquisition amount for mortgage on land		1,400,000
2020 Real Estate Acquisitions [Member] | Subsequent Event [Member] | Lamar Station Plaza East [Member]
Business Acquisition [Line Items]
Transaction costs capitalized for asset acquisitions	$ 100,000
Cash paid to prior investors	200,000
Business acquisition amount for mortgage on property	$ 2,500,000
2020 Real Estate Acquisitions [Member] | Subsequent Event [Member] | Lamar Station Plaza East [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Equity interest issued as consideration for the mergers | shares	884,143
2020 Real Estate Acquisitions [Member] | Subsequent Event [Member] | Lamar Station Plaza East [Member] | Loan Agreement [Member]
Business Acquisition [Line Items]
Maximum principal amount	$ 4,100,000
2020 Real Estate Acquisitions [Member] | Maximum [Member] | Cromwell Field Shopping Center [Member]
Business Acquisition [Line Items]
Transaction costs capitalized for asset acquisitions		$ 100,000
Geographic Concentration Risk [Member] | Rental Income [Member]
Business Acquisition [Line Items]
Number of properties acquired | property				0
Revenues			$ 7,791,000	$ 0