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, 2021	Mar. 31, 2020
Net loss per share – basic
Net loss	$ (4,450)	$ (2,672)
Weighted average number of shares outstanding, basic (in shares)	16,443	13,552
Net loss per share – basic (in dollars per share)	$ (0.27)	$ (0.20)
Net income (loss) per share – diluted
Net loss	$ (4,450)	$ (2,672)
Numerator effect of dilutive securities	(357)	(166)
Net loss available to common stockholders, diluted	$ (4,807)	$ (2,838)
Weighted average number of shares outstanding, basic (in shares)	16,443	13,552
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Weighted average number diluted shares outstanding adjustment	236	37
Weighted average number of shares outstanding, diluted (in shares)	16,679	13,589
Net loss per share – diluted (in dollars per share)	$ (0.29)	$ (0.21)
Warrants
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Incremental common shares attributable to dilutive effect of call options and warrants (in shares)	236	37