Note 7 - Mortgage and Other Indebtedness - (Details Textual) $ / shares in Units, $ in Thousands													1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
		Oct. 31, 2023 USD ($)	Sep. 29, 2023 USD ($)	Jul. 20, 2023 USD ($)	Jun. 30, 2023 USD ($)	May 05, 2023 USD ($)	May 03, 2023	May 01, 2023 USD ($)	Jan. 01, 2023	Jun. 04, 2021 USD ($)	May 21, 2021 USD ($)	Dec. 27, 2019 USD ($) Derivative	Dec. 31, 2019 USD ($) Subsidiary	Sep. 30, 2023 USD ($) $ / shares	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) $ / shares	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jul. 03, 2023	Nov. 23, 2022	Aug. 01, 2022	Oct. 06, 2021 USD ($)
Debt Instrument [Line Items]
Maturity date description																the Basis Term Loan (as defined below) had an outstanding principal balance of $35.2 million as of September 30, 2023 and matures on January 1, 2024, subject to the remaining one-year extension option that is subject to certain conditions, including a material adverse change clause, and approval by the lender.
Long-term debt outstanding														$ 234,812		$ 234,812
Interest expense														4,585	$ 3,073	14,101	$ 8,346
Balance outstanding														234,812		234,812
Principal balance of mortgage loan														233,445		233,445		$ 267,616
Mortgage loan														233,445		233,445		267,616
Income (expenses) related to fair value adjustments on derivatives														300	1,200	100	3,800
Net (loss) gain on fair value change of debt held under the fair value option														(816)	0	1,288	0
Change in fair value due to credit risk on debt held under the fair value option														$ 287	$ 0	687	$ 0
Highlandtown Village Shopping Center [Member]
Debt Instrument [Line Items]
Principal balance of mortgage loan						$ 8,700
Mortgage loan						$ 8,700
Mortgages [Member]
Debt Instrument [Line Items]
Outstanding mortgage indebtedness																$ 183,200		180,300
Mortgage Loan [Member] | Highlandtown Village Shopping Center [Member]
Debt Instrument [Line Items]
Mortgage loan maturity period						2028-05
Fortress Mezzanine Loan [Member]
Debt Instrument [Line Items]
Debt instrument variable rate														12.00%		12.00%
Fair value of loans														$ 16,700		$ 16,700		17,900
Debt Instrument, common stock conversion price | $ / shares														$ 2		$ 2
Interest expense														$ 500		$ 1,400
Principal balance of mortgage loan														$ 15,000		$ 15,000
Long term debt maturity date														Dec. 01, 2027		Dec. 01, 2027
Mortgage loan														$ 15,000		$ 15,000
Net (loss) gain on fair value change of debt held under the fair value option														800		1,300
Change in fair value due to credit risk on debt held under the fair value option														300		700
Capitalized interest														$ 300		$ 800
SOFR [Member] | Highlandtown Village Shopping Center [Member]
Debt Instrument [Line Items]
Debt instrument variable rate						2.50%
Current Interest Rate [Member] | Fortress Mezzanine Loan [Member]
Debt Instrument [Line Items]
Debt instrument variable rate														5.00%		5.00%
Capitalized Interest Rate [Member] | Fortress Mezzanine Loan [Member]
Debt Instrument [Line Items]
Debt instrument variable rate														7.00%		7.00%
Debt Instrument, interest rate increase each year																1.00%
Interest Rate Cap [Member] | Other Assets, Net [Member]
Debt Instrument [Line Items]
Fair value of derivative assets														$ 100		$ 100		200
Interest Rate Swap [Member] | Other Assets, Net [Member]
Debt Instrument [Line Items]
Fair value of derivative assets														1,900		1,900		3,200
Interest Rate Swap [Member] | Highlandtown Village Shopping Center [Member]
Debt Instrument [Line Items]
Debt instrument, effective interest rate						6.085%
Interest Rate Swap [Member] | Mortgage Loan [Member] | Highlandtown Village Shopping Center [Member]
Debt Instrument [Line Items]
Debt instrument, effective interest rate						6.085%
Basis Term Loan [Member]
Debt Instrument [Line Items]
Number of subsidiaries as borrowers entered in loan agreement | Subsidiary													6
Mortgage loans														$ 35,200		$ 35,200
Maturity date																Jan. 01, 2024
Maturity date description																The Basis Term Loan initial maturity was January 1, 2023, subject to two one-year extension options, subject to certain conditions.
Debt instrument variable rate														8.62%		8.62%
Long-term debt outstanding														$ 35,200		$ 35,200
Balance outstanding														35,200		35,200
Repayments of secured debt			$ 14,300	$ 17,400
Debt instrument net of discount														$ 11		$ 11		$ 79
Debt instrument, effective interest rate																			8.62%
Basis Term Loan [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayments of secured debt		$ 12,800
Basis Term Loan [Member] | SOFR [Member]
Debt Instrument [Line Items]
Debt instrument variable rate													3.97%			3.97%
Basis Term Loan [Member] | Interest Rate Cap [Member]
Debt Instrument [Line Items]
Mortgage loans												$ 66,900
Debt instrument, effective interest rate														8.62%		8.62%		6.125%
Basis Term Loan [Member] | Interest Rate Cap [Member] | London Interbank Offered Rate [Member]
Debt Instrument [Line Items]
Debt instrument variable rate														3.50%		3.50%
Basis Term Loan [Member] | Interest Rate Cap [Member] | SOFR [Member]
Debt Instrument [Line Items]
Debt instrument variable rate									3.97%
Debt instrument variable rate																				4.65%	3.50%
Basis Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Mortgage loans													$ 66,900
Debt instrument variable rate													6.125%	6.125%		6.125%
Basis Term Loan [Member] | Maximum [Member] | Interest Rate Cap [Member]
Debt Instrument [Line Items]
Debt instrument variable rate									6.125%
Lamont Street Preferred Interest [Member]
Debt Instrument [Line Items]
Description on extended redemption date																September 30, 2024 and September 30, 2025
Payment fee percentage, first extension option																0.25%
Payment fee percentage, second extension option																0.50%
Preferred Investor payments, description																Additionally, at the Lamont Street Redemption Date, Lamont Street was entitled to (i) a redemption fee of 0.50% of the capital contributions returned and (ii) an amount equal to (a) the product of (i) the aggregate amount of capital contributions made and (ii) 0.26 less (b) the aggregate amount of Lamont Street Class A Return payments made to Lamont Street (the “Lamont Street Minimum Multiple Amount”).
Percentage of redemption fee of capital contribution returned																0.50%
Repayments of secured debt					$ 2,300
Lamont Street Preferred Interest [Member] | Class A Units [Member]
Debt Instrument [Line Items]
Annual return percentage on initial capital contribution																13.50%
Cumulative annual return percentage, paid current																10.00%
Cumulative annual return percentage, accrued																3.50%
Lamont Street Preferred Interest [Member] | Class A Units [Member] | Highlandtown [Member]
Debt Instrument [Line Items]
Preferred investor, capital contribution											$ 3,900
Interest percentage in exchange of capital contribution											1.00%
Lamont Street Preferred Interest [Member] | Class A Units [Member] | Spotswood [Member]
Debt Instrument [Line Items]
Preferred investor, capital contribution										$ 3,900
Interest percentage in exchange of capital contribution										1.00%
Greenwood Village [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Mortgage loan maturity period																2028-10
Principal balance of mortgage loan																						$ 23,500
Mortgage loan																						$ 23,500
Debt instrument, effective interest rate								5.85%
Greenwood Village [Member] | Prime Rate [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Debt instrument variable rate																						0.35%
Greenwood Village [Member] | SOFR [Member]
Debt Instrument [Line Items]
Debt instrument variable rate								2.85%
Debt instrument, effective interest rate								5.85%
Greenwood Village [Member] | SOFR [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Debt instrument variable rate								2.85%
Greenwood Village [Member] | Interest Rate Swap [Member]
Debt Instrument [Line Items]
Debt instrument, effective interest rate								5.85%
Amount recieved on termination								$ 2,200
Interest Rate																						4.082%
Greenwood Village [Member] | Interest Rate Swap [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Debt instrument, effective interest rate																						4.082%
Highlandtown Mortgage [Member]
Debt Instrument [Line Items]
Repayments of secured debt						$ 1,900
Crestview Shopping Center Loan [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Debt instrument variable rate			7.83%
Mortgage loan maturity period			2026-09
Principal balance of mortgage loan			$ 12,000
Mortgage loan			$ 12,000
Coral Hills Shopping Center [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Debt instrument variable rate		6.95%
Mortgage loan maturity period																2033-10
Coral Hills Shopping Center [Member] | Subsequent Event [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Principal balance of mortgage loan		$ 12,800
Mortgage loan		$ 12,800
Vista Shops at Golden Mile Loan [Member]
Debt Instrument [Line Items]
Maturity date	[1]															Jun. 24, 2024
Debt instrument variable rate	[1]													3.83%		3.83%
Debt instrument net of discount														$ 0		$ 0		$ 12
Hollinswood Loan [Member] | SOFR [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Debt instrument variable rate							2.36%
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
Debt instrument additional borrowing available												3,000
Balance outstanding												$ 10,200
Number of derivatives held | Derivative												2

[1] On June 28, 2023, the Company entered into an agreement to extend the maturity date of this loan to June 24, 2024.