EARNINGS PER SHARE (Computation of Basic and Diluted Earnings per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Basic
Net income	$ 18,887	$ 16,215	$ 13,336	$ 12,117	$ 11,775	$ 10,783	$ 10,811	$ 6,097	$ 60,555	$ 39,466
Less: Earnings allocated to participating securities									(739)	(344)
Net income available to common stockholders									$ 59,816	$ 39,122
Weighted average common shares outstanding including participating securities									9,123,037	8,293,677
Less: Weighted average participating securities									(111,337)	(72,248)
Weighted average common shares outstanding									9,011,700	8,221,429
Basic earnings per common share (in dollars per share)	$ 1.74	$ 1.82	$ 1.59	$ 1.46	$ 1.42	$ 1.30	$ 1.30	$ 0.73	$ 6.64	$ 4.76
Diluted
Net income allocated to common shareholders									$ 59,816	$ 39,122
Weighted average common shares outstanding for basic earnings per common share									9,011,700	8,221,429
Average shares and dilutive potential common shares									9,272,822	8,398,444
Diluted earnings per common share (in dollars per share)	$ 1.69	$ 1.77	$ 1.55	$ 1.43	$ 1.39	$ 1.27	$ 1.28	$ 0.72	$ 6.45	$ 4.66
Stock Option
Diluted
Add: Dilutive effects of assumed exercise of stock options									170,792	103,463
Performance-Based Restricted Stock Units (PRSUs)
Diluted
Dilutive effects of assumed vesting units									51,581	73,552
Restricted stock awards
Calculations of basic and diluted earnings per share
Number of antidilutive shares not considered in computing diluted earnings per share									174,668	33,615
Diluted
Dilutive effects of assumed vesting units									38,749