ACCUMULATED OTHER COMPREHENSIVE INCOME - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	$ 62,558	$ 49,295	$ 164,214	$ 144,897
Net securities gains	0	0	0	797
Income tax expense	6,237	5,469	16,360	16,204
Other expense	3,724	2,694	10,262	6,842
Net income	28,525	24,119	77,840	71,450
Amount Reclassified From Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	(425)	(46)	(867)	494
Amount Reclassified From Accumulated Other Comprehensive Income | Held-to-Maturity Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	(504)		(995)
Income tax expense	106		209
Net income	(398)		(786)
Amount Reclassified From Accumulated Other Comprehensive Income | Available-for-Sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net securities gains		0		797
Income tax expense		0		(167)
Net income		0		630
Amount Reclassified From Accumulated Other Comprehensive Income | Defined Benefit Pension Items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	9	15	27	45
Other expense	(36)	(61)	(108)	(181)
Net income	$ (27)	$ (46)	$ (81)	$ (136)