Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2019	13,146,831	0
Balance at Dec. 31, 2019	$ 13	$ 0	$ 364,028	$ (342,945)	$ 21,096
Share-based compensation	$ 0	$ 0	1,984	0	$ 1,984
Issuance of common stock upon exercise of stock options (in shares)	22,373	0			22,373
Issuance of common stock upon exercise of stock options	$ 0	$ 0	75	0	$ 75
Net loss	$ 0	$ 0	0	(6,820)	(6,820)
Balance (in shares) at Dec. 31, 2020	13,169,204	0
Balance at Dec. 31, 2020	$ 13	$ 0	366,087	(349,765)	16,335
Share-based compensation	$ 0	$ 0	1,854	0	$ 1,854
Issuance of common stock upon exercise of stock options (in shares)	100,278	0			100,278
Issuance of common stock upon exercise of stock options	$ 0	$ 0	227	0	$ 227
Net loss	$ 0	$ 0	0	(5,659)	(5,659)
Issuance of restricted stock (in shares)	220,000	0
Balance (in shares) at Dec. 31, 2021	13,489,482	0
Balance at Dec. 31, 2021	$ 13	$ 0	$ 368,168	$ (355,424)	$ 12,757