EARNINGS (LOSS) PER SHARE - Computation of Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
EARNINGS (LOSS) PER SHARE
Net income (loss)	$ 4,193	$ 3,597	$ (931)	$ (2,551)	$ 7,790	$ (3,482)
Denominator:
Denominator for basic earnings (loss) per share - weighted average shares	8,806		8,820		8,826	8,737
Effect of dilutive securities:
Employee restricted stock and incentive stock options	141				150
Denominator for diluted earnings (loss) per share - adjusted weighted average shares and assumed conversion (in shares)	8,947		8,820		8,976	8,737
Basic earnings (loss) per share (in dollars per share)	$ 0.48		$ (0.11)		$ 0.88	$ (0.40)
Diluted earnings (loss) per share (in dollars per share)	$ 0.47		$ (0.11)		$ 0.87	$ (0.40)
Weighted average anti-dilutive employee restricted stock and incentive stock options (in shares)	114		348		126	393