CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Preferred Stock [Member] Convertible Preferred Stock - Series C [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Total	Convertible Preferred Stock - Series C [Member]
Beginning balance at Dec. 31, 2019	$ 1	$ 33	$ 243,180	$ (214,561)	$ 28,653
Beginning balance (in shares) at Dec. 31, 2019	2,103	32,932,273
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	430	0	430
Conversion of convertible preferred stock into common stock	$ (1)	$ 1	0	0	0
Conversion of convertible preferred stock into common stock (in shares)	(2,103)	782,089
Net loss	$ 0	$ 0	0	(1,035)	(1,035)
Ending balance at Mar. 31, 2020	$ 0	$ 34	243,610	(215,596)	28,048
Ending balance (in shares) at Mar. 31, 2020	0	33,714,362
Beginning balance at Dec. 31, 2019	$ 1	$ 33	243,180	(214,561)	28,653
Beginning balance (in shares) at Dec. 31, 2019	2,103	32,932,273
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss					(3,969)	$ (22)
Ending balance at Sep. 30, 2020	$ 0	$ 34	244,423	(218,530)	25,927
Ending balance (in shares) at Sep. 30, 2020	0	33,754,909
Beginning balance at Mar. 31, 2020	$ 0	$ 34	243,610	(215,596)	28,048
Beginning balance (in shares) at Mar. 31, 2020	0	33,714,362
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	410	0	410
Issuance of restricted stock	$ 0	$ 0	0	0	0
Issuance of restricted stock (in shares)	0	40,547
Net loss	$ 0	$ 0	0	(1,680)	(1,680)
Ending balance at Jun. 30, 2020	$ 0	$ 34	244,020	(217,276)	26,778
Ending balance (in shares) at Jun. 30, 2020	0	33,754,909
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	403	0	403
Net loss	0	0	0	(1,254)	(1,254)
Ending balance at Sep. 30, 2020	$ 0	$ 34	244,423	(218,530)	25,927
Ending balance (in shares) at Sep. 30, 2020	0	33,754,909
Beginning balance at Dec. 31, 2020		$ 34	244,831	(218,973)	25,892
Beginning balance (in shares) at Dec. 31, 2020		33,801,045
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		$ 0	662	0	662
Issuance of restricted stock		$ 0	0	0	0
Issuance of restricted stock (in shares)		16,260
Net loss		$ 0	0	(2,418)	(2,418)
Ending balance at Mar. 31, 2021		$ 34	245,493	(221,391)	24,136
Ending balance (in shares) at Mar. 31, 2021		33,817,305
Beginning balance at Dec. 31, 2020		$ 34	244,831	(218,973)	25,892
Beginning balance (in shares) at Dec. 31, 2020		33,801,045
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss					(1,857)	$ 0
Ending balance at Sep. 30, 2021		$ 34	246,979	(220,830)	26,183
Ending balance (in shares) at Sep. 30, 2021		34,364,679
Beginning balance at Mar. 31, 2021		$ 34	245,493	(221,391)	24,136
Beginning balance (in shares) at Mar. 31, 2021		33,817,305
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		$ 0	581		581
Issuance of restricted stock		$ 0	0		0
Issuance of restricted stock (in shares)		71,934
Net loss		$ 0	0	1,082	1,082
Ending balance at Jun. 30, 2021		$ 34	246,074	(220,309)	25,799
Ending balance (in shares) at Jun. 30, 2021		33,889,239
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		$ 0	320	0	320
Exercise of stock options		$ 0	0	0	0
Exercise of stock options (in shares)		329,076
Issuance of restricted stock		$ 0	0	0	0
Issuance of restricted stock (in shares)		146,364
Issuance of warrants		$ 0	585	0	585
Issuance of warrants (in shares)		0
Net loss				(521)	(521)
Ending balance at Sep. 30, 2021		$ 34	$ 246,979	$ (220,830)	$ 26,183
Ending balance (in shares) at Sep. 30, 2021		34,364,679