EARNINGS PER SHARE (Reconciliation of Basic and Diluted Earnings Per Share Computations) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator for basic and diluted earnings per share:
Net income	$ 134,837	$ 97,740	$ 65,636
Denominator:
Weighted basic shares outstanding (in shares)	55,479	55,845	56,148
Dilutive effect of equity-based compensation awards (in shares)	211	284	192
Weighted dilutive shares outstanding (in shares)	55,690	56,129	56,340
Basic earnings per share (in dollars per share)	$ 2.43	$ 1.75	$ 1.17
Diluted earnings per share (in dollars per share)	$ 2.42	$ 1.74	$ 1.16