NET INCOME PER COMMON SHARE - Computation of basic and diluted earnings per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Basic:
Net income	$ 1,731	$ 4,003	$ 1,247	$ 6,529
Weighted average common shares	47,426	45,115	46,704	44,491
Earnings per share	$ 0.04	$ 0.09	$ 0.03	$ 0.15
Diluted:
Net income	$ 1,731	$ 4,003	$ 1,247	$ 6,529
Basic weighted average common shares	47,426	45,115	46,704	44,491
Potential common shares	978	1,985	500	1,858
Diluted weighted average common shares	48,404	47,100	47,204	46,349
Diluted earnings per share	$ 0.04	$ 0.08	$ 0.03	$ 0.14