EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Basic
Net income, basic	$ 8,365	$ 10,114	$ 18,599	$ 26,569
Weighted average basic shares outstanding	21,774	21,714	21,750	21,700
Earnings per share (in dollars per share)	$ 0.38	$ 0.47	$ 0.86	$ 1.22
Diluted
Net income, diluted	$ 8,365	$ 10,114	$ 18,599	$ 26,569
Weighted average basic shares outstanding	21,774	21,714	21,750	21,700
Dilutive effect of stock-based awards (in shares)	157	90	143	80
Weighted average diluted shares outstanding	21,931	21,804	21,893	21,780
Earnings per share (in dollars per share)	$ 0.38	$ 0.46	$ 0.85	$ 1.22
Anti-dilutive shares excluded from calculation	117	195	115	267