Loans Payable and Secured Line of Credit - Additional Information (Details)					1 Months Ended				3 Months Ended		12 Months Ended
		Oct. 20, 2021 USD ($)	Jan. 31, 2020 USD ($) $ / shares	Jan. 15, 2020 USD ($) $ / shares	Oct. 31, 2021 USD ($) item $ / shares	Jun. 30, 2021 USD ($) item	Dec. 31, 2019 USD ($)	May 31, 2018 USD ($)	Mar. 31, 2022 USD ($) item $ / shares		Dec. 31, 2021 USD ($)		Dec. 31, 2020 USD ($) item $ / shares	Dec. 31, 2019 USD ($)	Nov. 10, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 22, 2020 $ / shares	Dec. 31, 2017 USD ($)
Accrued interest									$ 3,900,000		$ 3,800,000
Deferred finance fees									7,007,000
Loans Payable									$ 210,768,000	[1]	219,249,000	[1]				$ 207,317,000
Maximum number of committees of the board, that the Designee can sit | item									3
Warrants, Exercise Price (in dollars per share) | $ / shares					$ 4.31				$ 4.31								$ 4.50
Derivative Asset									$ 840,000
Secured Debt									12,750,000	[1]	$ 12,750,000	[1]				$ 8,950,000
Equity Method Investments									4,700,000
Repayment of loans	[1]								$ 11,642,000
Letter of credit
Debt Instrument, Interest Rate, Effective Percentage									3.50%		3.25%
250 North 10th JV
Equity Method Investment, Ownership Percentage			10.00%						10.00%
Sterling National Bank [Member]
Maximum borrowing capacity									$ 12,750,000
RCG LV Debt VI REIT LLC [Member]
Debt Instrument, Face Amount								$ 15,400,000
Principal amount								$ 15,400,000
Mezzanine Loan
Accrued interest									2,100,000		$ 1,100,000
Term of the debt													3 years
Loans Payable									30,300,000		30,300,000
Debt Instrument Blended Effective Interest Rate													8.30%
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
Debt Instrument, Face Amount													$ 7,500,000
Principal amount													$ 7,500,000
Greenwich Ny 77 [Member]
Loans Payable									159,400,000
Debt Instrument, Face Amount																		$ 189,500,000
Principal amount																		$ 189,500,000
Loans Payable 2018, 237 11th Loans
Delayed draw facility						$ 4,250,000
Debt Instrument, Interest Rate Terms								loan bearing interest at a blended average rate of 3.72% over the 30-day LIBOR, each with a one-year extension option upon satisfaction of certain conditions.
Debt Instrument, Interest Rate, Increase (Decrease)						25.00%
Exit fee (as a percent)						1.00%
Debt Instrument, Interest Rate, Effective Percentage						2.25%
Debt Instrument Exit Fee Rate, Increase (Decrease)						50.00%
Repayment of loans and secured line of credit						$ 56,400,000
Debt Instrument, Exit Fees						$ 567,000
Debt Instrument, Face Amount								$ 67,800,000
Principal amount								67,800,000
Loans Payable 2018, 237 11th Loans | Minimum
Interest rate basis (as a percent)						50.00%
Partner Loan
Term of the debt			4 years	4 years	1 year
Loans Payable									5,900,000		5,900,000
Debt Instrument, Interest Rate, Effective Percentage				7.00%
Debt Instrument, Number of Extensions | item					2
Debt Instrument , Extension Term					12 months
Threshold Maximum Common Stock Price Per Share, To Trigger Prepayment Of Debt Instrument | $ / shares			$ 6.50	$ 6.50
Debt Instrument, Face Amount			$ 5,900,000	$ 5,900,000	$ 10,500,000
Interest rate			7.00%		10.00%
Amount available for interest payments					$ 500,000
Amount funded at closing									10,100,000		10,000,000.0
Principal amount			$ 5,900,000	$ 5,900,000	10,500,000
250 North 10th Loan
Term of the debt				15 years
Debt Instrument, Face Amount				$ 82,750,000
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
Debt Instrument, Face Amount								52,400,000
Interest rate						3.05%
Principal amount								$ 52,400,000
New Senior Loan
Initial advance at closing									48,800,000		48,700,000
Debt Instrument, Face Amount						$ 50,000,000.0
Principal amount						50,000,000.0
New Mezzanine Loan
Initial advance at closing									10,000,000.0		10,000,000.0
Debt Instrument, Face Amount						10,000,000
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
Term of the debt		2 years
Loans Payable									116,000,000.0
Accrued PIK interest									2,500,000
Repayment of loans and secured line of credit									20,500,000
Debt Instrument, Face Amount					133,100,000
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
77 Mortgage Loan | Letter of credit
Minimum total return for mortgage lender		$ 4,000,000.0
Borrower guaranteed reduced amount		3,000,000.0
Pay-down amount per square feet of unsold residential units		$ 625
77 Mortgage Loan | Principal balance below $91.0 Million
Interest rate basis (as a percent)		7.00%
Interest rate		7.25%
77 Mortgage Loan | Principal balance equal or greater than $91.0 Million
Interest rate basis (as a percent)		9.25%
77 Mortgage Loan | LIBOR | Principal balance equal or greater than $91.0 Million
Interest rate basis (as a percent)		9.00%
Corporate Credit Facility
Increase in maximum borrowing capacity							$ 25,000,000.0							$ 25,000,000.0
Deferred finance fees									2,700,000		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, Basis for Effective Rate									9.5%		9.5%
Commitment fee							$ 2,450,000		$ 1,850,000					$ 2,450,000
Commitment fee, payable on the initial draw (as a percent)							50.00%							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
Reduction in commitments made by CCF									$ 7,500,000
Warrants, Exercise Price (in dollars per share) | $ / shares									$ 4.50				$ 6.50
Debt amount used to calculate the MOIC															$ 35,750,000
Maximum borrowing capacity							$ 70,000,000.0							$ 70,000,000.0
Corporate Credit Facility | Greenwich Ny 77 [Member]
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%
Secured Line of Credit
Loans Payable									$ 12,750,000		$ 12,750,000
Debt Instrument, Interest Rate Terms									The secured line of credit bears interest at the prime rate, currently 3.50%.  The secured line of credit

[1] Amounts are Restated. See Note 3 for more information.