Note 5 - Debt - (Details Textual)							1 Months Ended						3 Months Ended				12 Months Ended
		Mar. 18, 2021 USD ($)	Jul. 02, 2020 USD ($)	Jun. 16, 2020 USD ($) Capital	Apr. 20, 2020 USD ($)	Dec. 27, 2019 USD ($) Derivative	Mar. 31, 2021 USD ($)		Dec. 31, 2020 USD ($)		Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($) Subsidiary	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)		Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Long-term debt outstanding							$ 126,986,000							$ 126,986,000
Repayments of debt														9,372,000		$ 2,887,000
Principal balance of mortgage loan							125,037,000		$ 122,060,000					125,037,000			$ 122,060,000
PPP loan, interest rate					1.00%
Deferred financing costs, gross							1,600,000		1,400,000					1,600,000			1,400,000
Deferred financing costs, net							1,100,000		900,000					1,100,000			900,000
Debt discounts, gross							1,500,000		1,400,000					1,500,000			1,400,000
Debt instrument net of discount							$ 900,000		$ 900,000					900,000			$ 900,000
Income (expenses) related to fair value adjustments on derivatives														$ 200,000		(600,000)
2020 Real Estate Acquisitions [Member] | Lamar Station Plaza East [Member]
Debt Instrument [Line Items]
Assumption of debt			$ 2,500,000
2020 Real Estate Acquisitions [Member] | Lamar Station Plaza East [Member] | Loan Agreement [Member]
Debt Instrument [Line Items]
Maximum principal amount			$ 4,100,000
Debt instrument payment terms														The loan was in default of the debt service coverage ratio (as defined in the loan agreement) upon the Company’s assumption of the loan agreement.
MVB Revolver [Member]
Debt Instrument [Line Items]
Maturity date														Dec. 27, 2021			Dec. 27, 2021
Interest Rate	[1]						6.75%		6.75%					6.75%			6.75%
Mortgages [Member]
Debt Instrument [Line Items]
Outstanding mortgage indebtedness														$ 41,600,000			$ 38,100,000
PPP Loan [Member]
Debt Instrument [Line Items]
Unsecured loan					$ 800,000
Second PPP Loan [Member]
Debt Instrument [Line Items]
Maturity date		Mar. 18, 2026
Unsecured loan		$ 800,000
PPP loan, interest rate		1.00%
Sub-OP [Member]
Debt Instrument [Line Items]
Number of additional capital contribution from preferred investor | Capital				2
Preferred investor, additional capital contribution				$ 2,900,000							$ 2,900,000
Proceeds from refinance to repayment				750,000
Preferred units remaining contributed capital							$ 1,000,000							$ 1,000,000
LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument variable rate														0.11%
Prime Rate [Member] | MVB Revolver [Member]
Debt Instrument [Line Items]
Debt instrument variable rate														1.50%
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Fair value of interest rate swap liability							600,000		$ 700,000					$ 600,000			700,000
Interest Rate Swap [Member] | Accounts Payable and Accrued Expenses [Member]
Debt Instrument [Line Items]
Fair value of interest rate swap liability							500,000		700,000					500,000			700,000
Maximum [Member]
Debt Instrument [Line Items]
Deferred financing costs, amortization expense							200,000							200,000		$ 200,000
Maximum [Member] | Interest Rate Cap [Member]
Debt Instrument [Line Items]
Fair value of interest rate cap assets							100,000		100,000					100,000			100,000
Maximum [Member] | Interest Rate Cap [Member] | Other Assets, Net [Member]
Debt Instrument [Line Items]
Fair value of interest rate cap assets							$ 100,000		$ 100,000					$ 100,000			$ 100,000
Basis Term Loan [Member]
Debt Instrument [Line Items]
Number of subsidiaries as borrowers entered in loan agreement | Subsidiary												6
Maturity date												Jan. 01, 2023		Jan. 01, 2023			Jan. 01, 2023
Maturity date description														The Basis Term Loan matures on January 1, 2023, subject to two one-year extension options, subject to certain conditions.
Interest Rate							6.125%	[1]	6.125%	[1]		6.125%		6.125%	[1]		6.125%	[1]
Long-term debt outstanding							$ 66,900,000							$ 66,900,000
Preferred investor, additional capital contribution							2,900,000							2,900,000
Debt instrument net of discount							$ 653,000		$ 745,000					$ 653,000			$ 745,000
Basis Term Loan [Member] | Sub-OP [Member]
Debt Instrument [Line Items]
Preferred investor, additional capital contribution				2,400,000
Basis Term Loan [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument variable rate												3.85%		3.85%
Basis Term Loan [Member] | Interest Rate Cap [Member]
Debt Instrument [Line Items]
Long-term debt amount						$ 66,900,000
Debt instrument variable rate						6.125%
Basis Term Loan [Member] | Interest Rate Cap [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument variable rate						3.85%								3.50%
Derivative variable rate												3.50%
Debt instrument, effective interest rate						3.50%
Basis Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Long-term debt amount												$ 66,900,000
Basis Preferred Interest [Member]
Debt Instrument [Line Items]
Maturity date	[2],[3]													Jan. 01, 2023			Jan. 01, 2023
Interest Rate	[1],[3],[4]						14.00%		14.00%					14.00%			14.00%
Debt instrument net of discount							$ 131,000		$ 150,000					$ 131,000			$ 150,000
Basis Preferred Interest [Member] | Sub-OP [Member]
Debt Instrument [Line Items]
Preferred investor investment commitment amount												$ 10,700,000
Preferred investor, capital contribution														$ 6,900,000
Annual return percentage on initial capital contribution												14.00%
Interest percentage on excess of commitment amount												20.00%
Description on extended redemption date														December 31, 2023 and December 31, 2024
Payment fee percentage, first extension option												0.25%
Payment fee percentage, second extension option												0.50%
Preferred Investor payments, description														Additionally, at the Redemption Date, the Preferred Investor is entitled to an amount equal to (a) the product of (i) the aggregate amount of capital contributions made and (ii) 0.4, less (b) the aggregate amount of Class A return payments made to the Preferred Investor (the “Minimum Multiple Amount”).
Basis Preferred Interest [Member] | Sub-OP [Member] | Class A Units [Member]
Debt Instrument [Line Items]
Interest percentage in exchange of capital contribution														1.00%
Basis Preferred Interest [Member] | Maximum [Member]
Debt Instrument [Line Items]
Preferred investor investment commitment amount												$ 10,700,000
Basis Preferred Interest Minimum Multiple Amount [Member]
Debt Instrument [Line Items]
Long-term debt outstanding							1,500,000		$ 1,800,000					$ 1,500,000			$ 1,800,000
Basis Preferred Interest Minimum Multiple Amount [Member] | Sub-OP [Member]
Debt Instrument [Line Items]
Long-term debt outstanding							$ 1,500,000							1,500,000
Other Capital Contribution [Member] | Sub-OP [Member]
Debt Instrument [Line Items]
Preferred investor, additional capital contribution				$ 500,000
Preferred units, cumulative annual return				13.00%							13.00%
MVB Loan Agreement [Member]
Debt Instrument [Line Items]
Long-term debt outstanding												$ 6,500,000
Loan agreement deposit requirement														$ 3,000,000
Loan agreement deposit requirement default interest charges percentage														1.00%
MVB Loan Agreement [Member] | MVB Revolver [Member]
Debt Instrument [Line Items]
Maturity date									Dec. 27, 2021			Dec. 27, 2020		Dec. 27, 2022
Interest Rate							6.75%							6.75%
Long-term debt outstanding												$ 2,000,000
Line of credit facility, periodic payment required									$ 250,000					$ 250,000
Repayments of debt														$ 250,000
Line of credit facility, payments term									10 years					10 years
MVB Loan Agreement [Member] | MVB Term Loan [Member]
Debt Instrument [Line Items]
Maturity date												Dec. 27, 2022
Interest Rate												6.75%
Long-term debt outstanding												$ 4,500,000
MVB Loan Agreement [Member] | MVB Term Loan [Member] | MVB Revolver [Member]
Debt Instrument [Line Items]
Debt instrument additional borrowing available							$ 0							$ 0
MVB Loan Agreement [Member] | Prime Rate [Member] | MVB Revolver [Member]
Debt Instrument [Line Items]
Debt instrument variable rate												1.50%
MVB Loan Agreement [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.30%							1.30%
MVB Loan Agreement [Member] | Maximum [Member] | MVB Revolver [Member]
Debt Instrument [Line Items]
Debt service coverage ratio									1.00%								1.00%
MVB Loan Agreement [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.00%							1.00%
Consolidated funded debt ratio														8.00%
Funds available under other lines of credit														$ 5,000,000
MVB Loan Agreement [Member] | Minimum [Member] | MVB Revolver [Member]
Debt Instrument [Line Items]
Debt service coverage ratio									1.00%								1.00%
Funds available under other lines of credit									$ 3,000,000
Hollinswood Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.40%							1.40%
Hollinswood Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.00%							1.00%
Vista Mortgage [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.50%							1.50%
Vista Mortgage [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.00%							1.00%
Brookhill Mortgage [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.35%							1.35%
Brookhill Mortgage [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.00%							1.00%
Lamar Station Plaza East Mortgage [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.25%							1.25%
Lamar Station Plaza East Mortgage [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt service coverage ratio							1.00%							1.00%
Vista Shops at Golden Mile Loan [Member]
Debt Instrument [Line Items]
Maturity date														Jun. 24, 2023			Jun. 24, 2023
Interest Rate	[1]						3.83%		3.83%					3.83%			3.83%
Mortgage loan maturity period							2023-06
Principal balance of mortgage loan							$ 11,700,000							$ 11,700,000
Payment of basis preferred interest							1,900,000
Debt instrument net of discount							$ 83,000							$ 83,000
Vista Shops at Golden Mile Loan [Member] | Forecast [Member]
Debt Instrument [Line Items]
Payment of accrued interest													$ 46,000
Payment to escrow account													1,100,000
Vista Shops at Golden Mile Loan [Member] | Sub-OP [Member] | Forecast [Member]
Debt Instrument [Line Items]
Payment of basis preferred interest													$ 750,000
Hollinswood Loan [Member]
Debt Instrument [Line Items]
Maturity date														Dec. 01, 2024			Dec. 01, 2024
Interest Rate	[1]						4.06%		4.06%					4.06%			4.06%
Hollinswood Loan [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument variable rate														2.25%			2.25%
Hollinswood Loan [Member] | Interest Rate Cap [Member]
Debt Instrument [Line Items]
Debt instrument variable rate						4.06%
Hollinswood Loan [Member] | Interest Rate Swap [Member]
Debt Instrument [Line Items]
Long-term debt outstanding						$ 10,200,000
Debt instrument additional borrowing available						$ 3,000,000
Number of derivatives held | Derivative						2

[1] For floating rate loans tied to LIBOR, based on the one-month LIBOR rate of 0.11%, as of March 31, 2021.

[2] If the Basis Term Loan is paid in full earlier than its maturity date, the Basis Preferred Interest in the Sub-OP (as defined below) will mature at that time.

[3] The outstanding balance includes approximately $1.5 million and $1.8 million of indebtedness as of March 31, 2021 and December 31, 2020, respectively, related to the Multiple Minimum Amount owed to the Preferred Investor as described below under the heading “—Basis Preferred Interest”.

[4] In June 2020, the Preferred Investor made additional capital contributions of approximately $2.9 million as described below under the heading “—Basis Preferred Interest”. The Preferred Investor is entitled to a cumulative annual return of 13.0% on the additional contributions.