LOANS PAYABLE AND SECURED LINE OF CREDIT - Additional Information (Details)				1 Months Ended						12 Months Ended
	Oct. 01, 2023	Sep. 29, 2023 USD ($)	Jan. 15, 2020 USD ($)	Jan. 31, 2023 USD ($)	Jan. 31, 2022 USD ($)	Oct. 31, 2021 USD ($)	Jun. 30, 2021 USD ($) item	Dec. 31, 2020 USD ($) item $ / shares	Dec. 31, 2019 USD ($)	Dec. 31, 2022 USD ($) item $ / shares	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2021 USD ($)	Dec. 08, 2021 $ / shares	Dec. 22, 2020 $ / shares	Jan. 31, 2020	May 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Deferred finance fees										$ 3,375,000
Loans Payable										$ 208,762,000		$ 219,249,000
Warrants, Exercise Price (in dollars per share) | $ / shares										$ 4.31			$ 1.90	$ 4.50
Delayed draw facility										$ 2,000,000.0
250 North 10th JV
Equity method investment, ownership percentage										10.00%					10.00%
Sterling National Bank [Member]
Maximum borrowing capacity										$ 11,750,000
Loans Payable 2018, 237 11th Loans
Principal amount																$ 67,800,000
237 11th Loan
Repayment of loans and secured line of credit							$ 56,400,000
Debt Instrument, Exit Fees							$ 567,000
Principal amount																52,400,000
237 11th Mezzanine Loan
Principal amount																$ 15,400,000
Mezzanine Loan
Accrued interest										5,800,000
Term of the debt								3 years
Loans Payable										$ 30,300,000
Debt Instrument Blended Effective Interest Rate								9.44%		10.20%
Collateral for loan, equity interests in subsidiaries (as a percent)								100.00%			100.00%
Debt Instrument, Number of Extensions | item								2
Debt Instrument , Extension Term								1 year
Increase in loans including accrued interest						$ 22,770,000
Previously accrued interest						$ 770,000
Principal amount								$ 7,500,000			$ 7,500,000
Partner Loan
Term of the debt			4 years			1 year
Loans Payable										$ 5,900,000		5,900,000
Interest rate			7.00%			10.00%
Amount available for interest payments						$ 500,000
Amount funded at closing						10,100,000
Principal amount			$ 5,900,000			10,500,000
250 North 10th Loan
Term of the debt			15 years
Interest rate			3.39%
Principal amount			$ 82,750,000
New 237 11th Loans
Term of the debt							2 years
Debt Instrument, Number of Extensions | item							3
Debt Instrument , Extension Term							1 year
Proceeds From Debt Reserved To Cover Debt Service, Operating Expense Shortfall And Leasing Related Costs							$ 1,500,000
Interest rate							3.05%
Debt modification, gain (loss)										0
New Senior Loan
Initial advance at closing										50,000,000.0
Principal amount							$ 50,000,000.0
New Mezzanine Loan
Initial advance at closing										10,000,000.0
Principal amount							10,000,000
Interest Rate Cap Agreement New 237 11 Loan
Debt Instrument, Unamortized Premium							32,500
Derivative, Notional Amount							$ 60,000,000.0
Interest rate							2.50%
77 Mortgage Loan
Loans Payable										120,500,000
Repayment of loans and secured line of credit										47,800,000	$ 8,000,000.0
Maximum borrowing capacity						166,700,000
Proceeds from debt issuance used to fund construction and carry costs while condo units are being sold						33,600,000
Threshold amount of accrued and unpaid PIK interest and additional unused fee						91,000,000.0
Threshold amount for accrual of interests and additional unused fee						$ 4,500,000
Percentage of Additional Unused Fee						1.00%
Additional unused amount						$ 3,000,000.0
Minimum total return for mortgage lender						$ 15,260,000
Percentage of additional amounts advanced						10.00%
Principal amount						$ 133,100,000
Accrued PIK interest										4,700,000
Debt modification, gain (loss)										0
Debt, maximum loan balance, option to extend										70,000,000.0
77 Mortgage Loan | Principal balance below $91.0 Million
Interest rate						7.25%
77 Mortgage Loan | Principal balance equal or greater than $91.0 Million
Interest rate						9.25%
77 Mortgage Loan | LIBOR | Principal balance below $91.0 Million
Interest rate basis (as a percent)						7.00%
77 Mortgage Loan | LIBOR | Principal balance equal or greater than $91.0 Million
Interest rate basis (as a percent)						9.00%
Subsequent Event | 77 Mortgage Loan
Term of the debt	2 years
Subsequent Event | 77 Mortgage Loan | Letter of Credit [Member]
Proceeds from line of credit		$ 3,000,000.0
Payments of Paid in Kind Interest		$ 1,000,000.0
Corporate Credit Facility
Increase in maximum borrowing capacity									$ 25,000,000.0
Accrued interest										6,100,000		3,800,000
Interest paid				$ 419,000	$ 413,000
Deferred finance fees										1,300,000		2,900,000
Term of the debt									32 months
Loans Payable										$ 35,750,000		$ 35,750,000
Debt Instrument, Interest Rate Terms									a rate per annum equal to the sum of (i) 5.25% and (ii) a scheduled interest rate of 4% (the “Cash Pay Interest Rate”) which increases by 0.125% every six-month period from the Closing Date, subject to increase during the extension periods.
Debt Instrument, Interest Rate, Increase (Decrease)											0.125%
Debt Instrument, Interest Rate, Effective Percentage										10.00%		9.50%
Commitment fee									$ 2,450,000	$ 1,850,000
Commitment fee, payable on the initial draw (as a percent)										50.00%
Commitment fee, payable on subsequent draws (as a percent)										50.00%
Exit fee (as a percent)										1.00%
Multiple On Invested Capital (as a percent)										30.00%
Collateral for loan, equity interests in subsidiaries (as a percent)										100.00%
Common stock repurchase through proceeds from debt, amount authorized										$ 2,000,000.0
Common stock repurchase through other sources of cash, amount authorized										$ 1,500,000
Threshold minimum loan outstanding (as a percent)										50.00%
Number of board members who can be appointed by the lender | item										1
Maximum number of committees of the board, that the Designee can sit | item										3
Reduction in commitments made by CCF										$ 7,500,000
Warrants, Exercise Price (in dollars per share) | $ / shares								$ 6.50		$ 4.31	$ 6.50
Debt amount used to calculate the MOIC										$ 35,750,000
Maximum borrowing capacity									$ 70,000,000.0
Prepayment amount due on or prior to May 1, 2023										$ 7,000,000.0
Corporate Credit Facility | Greenwich NY 77
Net cash proceeds of residential condominium sales (as a percent)										70.00%
Corporate Credit Facility | Minimum
Net cash proceeds of residential condominium sales (as a percent)										90.00%
Corporate Credit Facility | Maximum
Net cash proceeds of residential condominium sales (as a percent)										100.00%
Corporate Credit Facility | PIK Interest Rate
Interest rate basis (as a percent)											5.25%
Corporate Credit Facility | Cash Pay Interest Rate
Interest rate basis (as a percent)											4.00%
Greenwich Construction Loan
Repayment of loans						$ 159,400,000
Principal amount																	$ 189,500,000
Secured Line of Credit
Loans Payable										$ 9,750,000		$ 12,750,000
Debt Instrument, Interest Rate, Effective Percentage										7.50%		3.25%