RESTATEMENT OF PREVIOUSLY ISSUED INTERIM CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) - Equity Statement (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021		Jun. 30, 2021		Sep. 30, 2021		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Revision of Previously Issued Consolidated Financial Statements
Balance	$ 48,386	$ 54,523	$ 62,020	[1]	$ 62,020	[1]	$ 62,020	[1]	$ 62,020	[1]	$ 55,964	[1]	$ 58,847
Net loss attributable to common stockholders	(3,608)	(6,434)	(7,419)		(13,853)		(17,461)		(20,805)		4,333	[1]	(5,292)	[1]
Settlement of stock awards		1	(370)		(369)		(370)		(370)		(696)		(772)
Unrealized gain on pension liability	119	118	119		237		356		816		1,015		1,992
Sale of common stock	166						167		7,639
Stock-based compensation expense	178	178	173		351		529		707		1,163		1,386
Stock-based consulting fees											600
Stock buy-back											(359)		(197)
Balance	45,241	48,386	54,523		48,386		45,241		50,007		62,020	[1]	55,964	[1]
Common Stock
Revision of Previously Issued Consolidated Financial Statements
Balance	$ 389	$ 388	$ 383	[1]	$ 383	[1]	$ 383	[1]	$ 383	[1]	$ 376	[1]	$ 372
Balance (in shares)	38,853	38,841	38,345	[1]	38,345	[1]	38,345	[1]	38,345	[1]	37,612	[1]	37,161
Net loss attributable to common stockholders									$ 0		$ 0		$ 0
Settlement of stock awards		$ 1	$ 5		$ 6		$ 5		$ 5		$ 5		$ 4
Settlement of stock awards (in shares)	13	12	496		508		521		535		543		451
Unrealized gain on pension liability									$ 0		$ 0		$ 0
Sale of common stock	$ 1						$ 2		$ 42
Sale of common stock (in shares)	150						150		4,144
Stock-based compensation expense									$ 0		0		0
Stock-based consulting fees											$ 2
Stock-based consulting fees (in shares)											190
Stock buy-back											$ 0		$ 0
Stock buy-back (in shares)									0				0
Balance	$ 390	$ 389	$ 388		$ 389		$ 390		$ 430		$ 383	[1]	$ 376	[1]
Balance (in shares)	39,016	38,853	38,841		38,853		39,016		43,024		38,345	[1]	37,612	[1]
Additional Paid-In Capital
Revision of Previously Issued Consolidated Financial Statements
Balance	$ 136,329	$ 136,151	$ 135,978	[1]	$ 135,978	[1]	$ 135,978	[1]	$ 135,978	[1]	$ 134,217	[1]	$ 132,831
Net loss attributable to common stockholders									0		0		0
Settlement of stock awards									0		0		0
Unrealized gain on pension liability									0		0		0
Sale of common stock	165						165		7,597
Stock-based compensation expense	178	178	173		351		529		707		1,163		1,386
Stock-based consulting fees											598
Stock buy-back											0		0
Balance	136,672	136,329	136,151		136,329		136,672		144,282		135,978	[1]	134,217	[1]
Treasury Stock
Revision of Previously Issued Consolidated Financial Statements
Balance	$ (57,166)	$ (57,166)	$ (56,791)	[1]	$ (56,791)	[1]	$ (56,791)	[1]	$ (56,791)	[1]	$ (55,731)	[1]	$ (54,758)
Balance (in shares)	(6,398)	(6,398)	(6,173)	[1]	(6,173)	[1]	(6,173)	[1]	(6,173)	[1]	(5,731)	[1]	(5,514)
Net loss attributable to common stockholders									$ 0		$ 0		$ 0
Settlement of stock awards			$ (375)		$ (375)		$ (375)		$ (375)		$ (701)		$ (776)
Settlement of stock awards (in shares)			(225)		(225)		(225)		(225)		(222)		(187)
Unrealized gain on pension liability									$ 0		$ 0		$ 0
Sale of common stock									0
Stock-based compensation expense									$ 0		0		0
Stock-based consulting fees											0
Stock buy-back											$ (359)		$ (197)
Stock buy-back (in shares)									0		(220)		(30)
Balance	$ (57,166)	$ (57,166)	$ (57,166)		$ (57,166)		$ (57,166)		$ (57,166)		$ (56,791)	[1]	$ (55,731)	[1]
Balance (in shares)	(6,398)	(6,398)	(6,398)		(6,398)		(6,398)		(6,398)		(6,173)	[1]	(5,731)	[1]
Accumulated Deficit
Revision of Previously Issued Consolidated Financial Statements
Balance	$ (29,244)	$ (22,810)	$ (15,391)	[1]	$ (15,391)	[1]	$ (15,391)	[1]	$ (15,391)	[1]	$ (19,724)	[1]	$ (16,080)
Net loss attributable to common stockholders	(3,608)	(6,434)	(7,419)		(13,853)		(17,461)		(20,805)		4,333		(5,292)
Settlement of stock awards									0		0		0
Unrealized gain on pension liability									0		0		1,648
Sale of common stock									0
Stock-based compensation expense									0		0		0
Stock-based consulting fees											0
Stock buy-back											0		0
Balance	(32,852)	(29,244)	(22,810)		(29,244)		(32,852)		(36,196)		(15,391)	[1]	(19,724)	[1]
Accumulated Other Comprehensive Loss
Revision of Previously Issued Consolidated Financial Statements
Balance	(1,922)	(2,040)	(2,159)	[1]	(2,159)	[1]	(2,159)	[1]	(2,159)	[1]	(3,174)	[1]	(3,518)
Net loss attributable to common stockholders									0		0		0
Settlement of stock awards									0		0		0
Unrealized gain on pension liability	119	118	119		237		356		816		1,015		344
Sale of common stock									0
Stock-based compensation expense									0		0		0
Stock-based consulting fees											0
Stock buy-back											0		0
Balance	(1,803)	(1,922)	(2,040)		(1,922)		(1,803)		(1,343)		(2,159)	[1]	(3,174)	[1]
Error Related to Classification of Real Estate Under Development | As Previously Reported
Revision of Previously Issued Consolidated Financial Statements
Balance	56,824	61,241	67,908		67,908		67,908		67,908		59,691		59,461
Net loss attributable to common stockholders	(1,032)	(4,714)	(6,589)		(11,303)		(12,335)		(16,474)		6,494		(2,179)
Settlement of stock awards		1	(370)		(369)		(370)		(370)		(696)		(772)
Unrealized gain on pension liability	119	118	119		237		356		816		1,015		1,992
Sale of common stock	166						167		7,639
Stock-based compensation expense	178	178	173		351		529		707		1,163		1,386
Stock-based consulting fees											600
Stock buy-back											(359)		(197)
Balance	56,255	56,824	61,241		56,824		56,255		60,226		67,908		59,691
Error Related to Classification of Real Estate Under Development | As Previously Reported | Common Stock
Revision of Previously Issued Consolidated Financial Statements
Balance	$ 389	$ 388	$ 383		$ 383		$ 383		$ 383		$ 376		$ 372
Balance (in shares)	38,853	38,841	38,345		38,345		38,345		38,345		37,612		37,161
Settlement of stock awards		$ 1	$ 5		$ 6		$ 5		$ 5		$ 5		$ 4
Settlement of stock awards (in shares)	13	12	496		508		521		535		543		451
Sale of common stock	$ 1						$ 2		$ 42
Sale of common stock (in shares)	150						150		4,144
Stock-based consulting fees											$ 2
Stock-based consulting fees (in shares)											190
Balance	$ 390	$ 389	$ 388		$ 389		$ 390		$ 430		$ 383		$ 376
Balance (in shares)	39,016	38,853	38,841		38,853		39,016		43,024		38,345		37,612
Error Related to Classification of Real Estate Under Development | As Previously Reported | Additional Paid-In Capital
Revision of Previously Issued Consolidated Financial Statements
Balance	$ 136,329	$ 136,151	$ 135,978		$ 135,978		$ 135,978		$ 135,978		$ 134,217		$ 132,831
Sale of common stock	165						165		7,597
Stock-based compensation expense	178	178	173		351		529		707		1,163		1,386
Stock-based consulting fees											598
Balance	136,672	136,329	136,151		136,329		136,672		144,282		135,978		134,217
Error Related to Classification of Real Estate Under Development | As Previously Reported | Treasury Stock
Revision of Previously Issued Consolidated Financial Statements
Balance	$ (57,166)	$ (57,166)	$ (56,791)		$ (56,791)		$ (56,791)		$ (56,791)		$ (55,731)		$ (54,758)
Balance (in shares)	(6,398)	(6,398)	(6,173)		(6,173)		(6,173)		(6,173)		(5,731)		(5,514)
Settlement of stock awards			$ (375)		$ (375)		$ (375)		$ (375)		$ (701)		$ (776)
Settlement of stock awards (in shares)			(225)		(225)		(225)		(225)		(222)		(187)
Stock buy-back											$ (359)		$ (197)
Stock buy-back (in shares)											(220)		(30)
Balance	$ (57,166)	$ (57,166)	$ (57,166)		$ (57,166)		$ (57,166)		$ (57,166)		$ (56,791)		$ (55,731)
Balance (in shares)	(6,398)	(6,398)	(6,398)		(6,398)		(6,398)		(6,398)		(6,173)		(5,731)
Error Related to Classification of Real Estate Under Development | As Previously Reported | Accumulated Deficit
Revision of Previously Issued Consolidated Financial Statements
Balance	$ (20,806)	$ (16,092)	$ (9,503)		$ (9,503)		$ (9,503)		$ (9,503)		$ (15,997)		$ (15,466)
Net loss attributable to common stockholders	(1,032)	(4,714)	(6,589)		(11,303)		(12,335)		(16,474)		6,494		(2,179)
Unrealized gain on pension liability													1,648
Balance	(21,838)	(20,806)	(16,092)		(20,806)		(21,838)		(25,977)		(9,503)		(15,997)
Error Related to Classification of Real Estate Under Development | As Previously Reported | Accumulated Other Comprehensive Loss
Revision of Previously Issued Consolidated Financial Statements
Balance	(1,922)	(2,040)	(2,159)		(2,159)		(2,159)		(2,159)		(3,174)		(3,518)
Unrealized gain on pension liability	119	118	119		237		356		816		1,015		344
Balance	(1,803)	(1,922)	(2,040)		(1,922)		(1,803)		(1,343)		(2,159)		(3,174)
Error Related to Classification of Real Estate Under Development | Revision/Restatement Impact
Revision of Previously Issued Consolidated Financial Statements
Balance	(8,438)	(6,718)	(5,888)		(5,888)		(5,888)		(5,888)		(3,727)		(614)
Net loss attributable to common stockholders	(2,576)	(1,720)	(830)		(2,550)		(5,126)		(4,331)		(2,161)		(3,113)
Balance	(11,014)	(8,438)	(6,718)		(8,438)		(11,014)		(10,219)		(5,888)		(3,727)
Error Related to Classification of Real Estate Under Development | Revision/Restatement Impact | Accumulated Deficit
Revision of Previously Issued Consolidated Financial Statements
Balance	(8,438)	(6,718)	(5,888)		(5,888)		(5,888)		(5,888)		(3,727)		(614)
Net loss attributable to common stockholders	(2,576)	(1,720)	(830)		(2,550)		(5,126)		(4,331)		(2,161)		(3,113)
Balance	$ (11,014)	$ (8,438)	$ (6,718)		$ (8,438)		$ (11,014)		$ (10,219)		$ (5,888)		$ (3,727)

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