Net Income (Loss) Per Common Share (Computation of Basic and Diluted Net Loss Per Common Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income (loss)	$ 7,890	$ (7,000)	$ 868	$ (11,742)
Denominator:
Weighted average number of shares of common stock outstanding	8,917,858	8,829,732	8,902,484	8,813,880
Weighted average effect of dilutive share-based compensation	164,513		148,363
Diluted weighted average number of shares of common stock outstanding	9,082,371	8,829,732	9,050,847	8,813,880
Net income (loss) per common share:
Net income (loss) per common share - Basic	$ 0.88	$ (0.79)	$ 0.10	$ (1.33)
Net income (loss) per common share - Diluted	$ 0.87	$ (0.79)	$ 0.10	$ (1.33)