EARNINGS PER SHARE - Schedule of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net earnings (basic)	$ 7,530	$ 5,091	$ 18,910	$ 14,084
Net earnings (diluted)	$ 7,530	$ 5,091	$ 18,910	$ 14,084
Denominator:
Weighted-average shares outstanding (basic) (in shares)	11,550,335	11,962,654	11,674,298	11,452,968
Effect of dilutive securities:
Common stock equivalent shares from stock options (in shares)	62,538	70,780	58,844	100,539
Weighted-average shares outstanding (diluted) (in shares)	11,612,873	12,033,434	11,733,142	11,553,507
Net earnings per share
Basic (in USD per share)	$ 0.65	$ 0.43	$ 1.62	$ 1.23
Diluted (in USD per share)	$ 0.65	$ 0.42	$ 1.62	$ 1.22