EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Basic earnings per share:
NET INCOME	$ 13,192	$ 10,845	$ 29,078	$ 18,078
Weighted-average common shares	29,856,000	29,297,000	29,729,000	29,125,000
Basic earnings per share	$ 0.44	$ 0.37	$ 0.98	$ 0.62
Diluted earnings per share:
NET INCOME	$ 13,192	$ 10,845	$ 29,078	$ 18,078
Weighted-average common shares	29,856,000	29,297,000	29,729,000	29,125,000
Effect of dilutive awards:
Employee stock plans	456,000	405,000	503,000	472,000
Diluted weighted-average common shares	30,312,000	29,702,000	30,232,000	29,597,000
Diluted earnings per share	$ 0.44	$ 0.37	$ 0.96	$ 0.61
Stock awards excluded in the computation of diluted earnings per share	0	0	0	0