Computation of Net Loss Per Share of Common Stock (Components of Net Income (Loss) Per Basic and Diluted Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net loss per share – basic
Net loss	$ (4,640)	$ (4,450)
Weighted average number of shares outstanding, basic (in shares)	18,014	16,443
Net loss per share – basic (in dollars per share)	$ (0.26)	$ (0.27)
Net income (loss) per share – diluted
Net loss	$ (4,640)	$ (4,450)
Numerator effect of dilutive securities	0	(357)
Net loss available to common stockholders, diluted	$ (4,640)	$ (4,807)
Weighted average number of shares outstanding, basic (in shares)	18,014	16,443
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Weighted average number diluted shares outstanding adjustment	0	236
Weighted average number of shares outstanding, diluted (in shares)	18,014	16,679
Net loss per share – diluted (in dollars per share)	$ (0.26)	$ (0.29)
Warrants
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Incremental common shares attributable to dilutive effect of call options and warrants (in shares)	0	236