EARNINGS PER SHARE - Earnings Per Share Computations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Basic earnings per common share:
Net income	$ 29,626	$ 25,252	$ 14,611	$ 24,278	$ 25,977	$ 28,525	$ 25,673	$ 23,642	$ 93,767	$ 103,817	$ 95,733
Weighted-average common shares outstanding (in shares)									25,604,751	25,528,328	25,475,994
Basic earnings per common share (in USD per share)	$ 1.16	$ 0.99	$ 0.57	$ 0.95	$ 1.02	$ 1.12	$ 1.00	$ 0.93	$ 3.67	$ 4.07	$ 3.76
Diluted earnings per common share:
Net income	$ 29,626	$ 25,252	$ 14,611	$ 24,278	$ 25,977	$ 28,525	$ 25,673	$ 23,642	$ 93,767	$ 103,817	$ 95,733
Weighted-average common shares outstanding (in shares)									25,604,751	25,528,328	25,475,994
Add: Dilutive effect of assumed exercises of stock options and awards (in shares)									118,414	184,210	144,111
Average shares and dilutive potential common shares (in shares)									25,723,165	25,712,538	25,620,105
Diluted earnings per common share (in USD per share)	$ 1.16	$ 0.98	$ 0.57	$ 0.94	$ 1.01	$ 1.11	$ 1.00	$ 0.92	$ 3.65	$ 4.04	$ 3.74
Number of antidilutive stock options (in shares)									0	0	0