EARNINGS PER SHARE (Computation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income		$ 13,204	$ 12,217	$ 27,477	$ 25,037
Dividends and undistributed earnings allocated to participating securities	[1]	(26)	(30)	(54)	(70)
Net income available to common shareholders		$ 13,178	$ 12,187	$ 27,423	$ 24,967
Weighted-average common shares outstanding for basic EPS		15,519,827	15,572,848	15,555,770	15,557,500
Dilutive effect of stock-based awards (shares)	[2]	39,933	56,931	39,884	57,538
Weighted-average common and potential common shares for diluted EPS (shares)		15,559,760	15,629,779	15,595,654	15,615,038
Basic EPS (in dollars per share)		$ 0.85	$ 0.78	$ 1.76	$ 1.60
Diluted EPS (in dollars per share)		$ 0.85	$ 0.78	$ 1.76	$ 1.60
Antidilutive Stock options (shares)		0	0	0	0

[1] (1)Represents dividends paid and undistributed earnings allocated to nonvested stock-based awards that contain non-forfeitable rights to dividends.

[2] (2)Represents the effect of the assumed exercise of stock options and vesting of restricted shares and restricted stock units utilizing the treasury stock method. Not included are the unvested LTIP awards, which are the Company's performance-based awards.