EARNINGS PER COMMON SHARE - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Basic earnings per common share computation:
Net income per condensed consolidated statements of income	$ 14,170	$ 13,106
Net earnings allocated to participating securities	(63)	(45)
Net earnings allocated to common stock	$ 14,107	$ 13,061
Weighted average common shares outstanding, including shares considered participating securities (in shares)	16,883	16,855
Less: Average participating securities (in shares)	(72)	(56)
Weighted average shares (in shares)	16,811	16,799
Basic earnings per common share (in dollar per share)	$ 0.84	$ 0.78
Diluted earnings per common share computation:
Net earnings allocated to common stock	$ 14,107	$ 13,061
Weighted average common shares outstanding for basic earnings per common share (in shares)	16,811	16,799
Add: Dilutive effects of performance based-shares (in shares)	33	0
Weighted average shares and dilutive potential common shares (in shares)	16,844	16,799
Diluted earnings per common share (in dollar per share)	$ 0.84	$ 0.78
Distributed earnings allocated to common stock
Basic earnings per common share computation:
Net earnings allocated to common stock	$ 2,944	$ 2,859
Undistributed earnings allocated to common stock
Basic earnings per common share computation:
Net earnings allocated to common stock	$ 11,163	$ 10,202