RESTATEMENT OF PREVIOUSLY ISSUED INTERIM CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) - Cash Flows (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Nov. 23, 2019	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2021	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss attributable to common stockholders		$ (3,608)	$ (6,434)	$ (7,419)	$ (13,853)	$ (17,461)	$ (20,805)	$ 4,333	[1]	$ (5,292)	[1]
Adjustments to reconcile net loss (income) attributable to common stockholders to net cash used in operating activities:
Depreciation and amortization and amortization of deferred finance costs				1,261	2,944	4,214	5,524	4,168		4,157
Stock-based compensation expense				133	265	399	530	806		905
Gain on sale of school condominium							0	(24,196)	[1]	0	[1]
Gain on sale of real estate	$ 9,500						0	0	[1]	(9,521)	[1]
Gain on sale of school condominium										(9,521)
Deferred rents receivable				(12)	(16)	(20)	(24)	(84)		578
Other non-cash adjustments - pension expense				119	238	356	816	1,015		1,992
Unrealized loss (gain) on warrants		(1,718)	(67)	1,977	1,910	192	(73)	(965)	[1]	0	[1]
Equity in net loss from unconsolidated joint ventures			264	372	636	636	555	1,571	[1]	819	[1]
Distributions from unconsolidated joint ventures				194	425	686	885	1,110		33
Loan forgiveness					(243)	(243)
(Increase) decrease in operating assets:
Residential condominium units for sale				(11,672)	(19,479)	(25,371)	(11,450)	(46,473)		(65,098)
Receivables				47	820	887	882	2,392		1,577
Prepaid expenses and other assets, net				(371)	(97)	(846)	(257)	190		278
Increase (decrease) in operating liabilities:
Accounts payable and accrued expenses				1,294	3,559	5,775	3,467	1,285		1,649
Pension liabilities							(1,288)	(1,033)		(2,705)
Net cash used in operating activities				(14,077)	(22,891)	(30,796)	(21,238)	(55,881)		(70,628)
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to real estate				(53)	(56)	(84)	(140)	(4,279)		(24,816)
Net proceeds from the sale of real estate							0	0		18,812
Deferred real estate deposits of SCA condominium							0	0		33,609
Investments in unconsolidated joint ventures							0	(5,383)		0
Net (cash used in) provided by investing activities				(53)	(56)	(84)	(140)	(9,662)		27,605
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from loans and corporate credit facility				8,980	74,486	82,318	249,984	86,361		55,475
Proceeds from secured line of credit				1,200	1,200	4,200	8,200	5,000		7,250
Payment of finance costs				(21)	(2,231)	(2,442)	(6,552)	(1,497)		(1,531)
Repayment of loans					(56,413)	(56,413)	(225,547)	(23,368)		(10,557)
Repayment of secured line of credit							(3,200)	(2,500)		(2,000)
Settlement of stock awards				(370)	(369)	(370)	(370)	(695)		(772)
Stock buy-back							0	(359)		(197)
Sale of common stock, net						167	7,639	0		0
Net cash provided by financing activities				9,789	16,673	27,460	30,154	62,942		47,668
NET DECREASE IN CASH AND CASH EQUIVALENTS AND RESTRICTED CASH				(4,341)	(6,274)	(3,420)	8,776	(2,601)		4,645
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD		9,795	11,728	16,069	16,069	16,069	16,069	18,670		14,025
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD		12,649	9,795	11,728	9,795	12,649	24,845	16,069		18,670
CASH AND CASH EQUIVALENTS, BEGINNING PERIOD		2,169	5,034	6,515	6,515	6,515	6,515	9,196		11,496
RESTRICTED CASH, BEGINNING OF PERIOD		7,626	6,694	9,554	9,554	9,554	9,554	9,474		2,529
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD		9,795	11,728	16,069	16,069	16,069	16,069	18,670		14,025
CASH AND CASH EQUIVALENTS, END OF PERIOD		917	2,169	5,034	2,169	917	4,310	6,515		9,196
RESTRICTED CASH, END OF PERIOD		11,732	7,626	6,694	7,626	11,732	20,535	9,554		9,474
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD		12,649	9,795	11,728	9,795	12,649	24,845	16,069		18,670
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid during the period for: Interest				4,130	8,564	13,329	16,042	15,495		12,631
Cash paid during the period for: Taxes				46	49	189	395	251		352
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Capitalized amortization of deferred financing costs and warrants				692	1,501	2,169	3,193	2,668		2,700
Capitalized stock-based compensation expense				37	70	97	122	299		401
Loan forgiveness							243	0		0
Investment in unconsolidated joint venture							0	5,193		0
Right-of-use asset							0	0		1,904
Lease liabilities							0	0		(2,065)
Warrant liability							0	0		(1,795)
Error Related to Classification of Real Estate Under Development | As Previously Reported
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss attributable to common stockholders		(1,032)	(4,714)	(6,589)	(11,303)	(12,335)	(16,474)	6,494		(2,179)
Adjustments to reconcile net loss (income) attributable to common stockholders to net cash used in operating activities:
Depreciation and amortization and amortization of deferred finance costs				908	2,246	3,122	3,998	2,970		2,977
Stock-based compensation expense				133	265	399	530	806		905
Gain on sale of school condominium								(24,196)
Gain on sale of real estate										(9,521)
Gain on sale of school condominium										(9,521)
Deferred rents receivable				(12)	(16)	(20)	(24)	(84)		578
Other non-cash adjustments - pension expense				119	238	356	816	1,015		1,992
Unrealized loss (gain) on warrants		(1,718)	(67)	1,977	1,910	192	(73)	(965)
Equity in net loss from unconsolidated joint ventures			264	372	636	636	555	1,571		819
Distributions from unconsolidated joint ventures				194	425	686	885	1,110		33
Loan forgiveness					(243)	(243)
(Increase) decrease in operating assets:
Residential condominium units for sale						(33)	(321)
Receivables				47	820	887	882	2,392		1,577
Prepaid expenses and other assets, net				(371)	(97)	(846)	(257)	190		278
Increase (decrease) in operating liabilities:
Accounts payable and accrued expenses				1,294	3,559	5,775	3,467	(686)		1,649
Pension liabilities							(1,288)	(1,033)		(2,705)
Net cash used in operating activities				(1,928)	(1,560)	(1,424)	(7,304)	(10,416)		(3,597)
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to real estate				(12,202)	(21,387)	(30,784)	(36,349)	(51,715)		(91,847)
Net proceeds from the sale of real estate						1,328	22,275			18,812
Deferred real estate deposits of SCA condominium								1,971		33,609
Investments in unconsolidated joint ventures								(5,383)
Net (cash used in) provided by investing activities				(12,202)	(21,387)	(29,456)	(14,074)	(55,127)		(39,426)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from loans and corporate credit facility				8,980	74,486	82,318	249,984	86,361		55,475
Proceeds from secured line of credit				1,200	1,200	4,200	8,200	5,000		7,250
Payment of finance costs				(21)	(2,231)	(2,442)	(6,552)	(1,497)		(1,531)
Repayment of loans					(56,413)	(56,413)	(225,547)	(23,368)		(10,557)
Repayment of secured line of credit							(3,200)	(2,500)		(2,000)
Settlement of stock awards				(370)	(369)	(370)	(370)	(695)		(772)
Stock buy-back								(359)		(197)
Sale of common stock, net						167	7,639
Net cash provided by financing activities				9,789	16,673	27,460	30,154	62,942		47,668
NET DECREASE IN CASH AND CASH EQUIVALENTS AND RESTRICTED CASH				(4,341)	(6,274)	(3,420)	8,776	(2,601)		4,645
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD		9,795	11,728	16,069	16,069	16,069	16,069	18,670		14,025
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD		12,649	9,795	11,728	9,795	12,649	24,845	16,069		18,670
CASH AND CASH EQUIVALENTS, BEGINNING PERIOD		2,169	5,034	6,515	6,515	6,515	6,515	9,196		11,496
RESTRICTED CASH, BEGINNING OF PERIOD		7,626	6,694	9,554	9,554	9,554	9,554	9,474		2,529
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD		9,795	11,728	16,069	16,069	16,069	16,069	18,670		14,025
CASH AND CASH EQUIVALENTS, END OF PERIOD		917	2,169	5,034	2,169	917	4,310	6,515		9,196
RESTRICTED CASH, END OF PERIOD		11,732	7,626	6,694	7,626	11,732	20,535	9,554		9,474
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD		12,649	9,795	11,728	9,795	12,649	24,845	16,069		18,670
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid during the period for: Interest				4,130	8,564	13,329	16,042	15,495		12,631
Cash paid during the period for: Taxes				46	49	189	395	251		352
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Accrued development costs included in accounts payable and accrued expenses				7,496	8,321	7,101	8,805	10,319		12,698
Capitalized amortization of deferred financing costs and warrants				760	1,629	2,406	3,580	2,727		2,739
Capitalized stock-based compensation expense				39	85	130	177	356		480
Loan forgiveness							243
Investment in unconsolidated joint venture								5,193
Right-of-use asset										1,904
Lease liabilities										(2,065)
Warrant liability										(1,795)
Error Related to Classification of Real Estate Under Development | Revision/Restatement Impact
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss attributable to common stockholders		$ (2,576)	$ (1,720)	(830)	(2,550)	(5,126)	(4,331)	(2,161)		(3,113)
Adjustments to reconcile net loss (income) attributable to common stockholders to net cash used in operating activities:
Depreciation and amortization and amortization of deferred finance costs				353	698	1,092	1,526	1,198		1,180
(Increase) decrease in operating assets:
Residential condominium units for sale				(11,672)	(19,479)	(25,338)	(11,129)	(46,473)		(65,098)
Increase (decrease) in operating liabilities:
Accounts payable and accrued expenses								1,971
Net cash used in operating activities				(12,149)	(21,331)	(29,372)	(13,934)	(45,465)		(67,031)
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to real estate				12,149	21,331	30,700	36,209	47,436		67,031
Net proceeds from the sale of real estate						(1,328)	(22,275)
Deferred real estate deposits of SCA condominium								(1,971)
Net (cash used in) provided by investing activities				12,149	21,331	29,372	13,934	45,465		67,031
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Accrued development costs included in accounts payable and accrued expenses				(7,496)	(8,321)	(7,101)	(8,805)	(10,319)		(12,698)
Capitalized amortization of deferred financing costs and warrants				(68)	(128)	(237)	(387)	(59)		(39)
Capitalized stock-based compensation expense				$ (2)	$ (15)	$ (33)	$ (55)	$ (57)		$ (79)

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