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, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net earnings (basic)	$ 10,134	$ 7,530	$ 17,487	$ 18,910
Net earnings (diluted)	$ 10,134	$ 7,530	$ 17,487	$ 18,910
Denominator:
Weighted-average shares outstanding (basic) (in shares)	11,012,060	11,550,335	11,156,263	11,674,298
Effect of dilutive securities:
Common stock equivalent shares from stock options (in shares)		62,538		58,844
Weighted-average shares outstanding (diluted) (in shares)	11,012,060	11,612,873	11,156,263	11,733,142
Net earnings per share
Basic (in USD per share)	$ 0.92	$ 0.65	$ 1.57	$ 1.62
Diluted (in USD per share)	$ 0.92	$ 0.65	$ 1.57	$ 1.62