ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY - Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 72,058	$ 67,523	$ 72,606	$ 67,773
Provision for credit losses	400	0	5,550	417
Loans charged-off	(480)	(373)	(6,766)	(1,211)
Recoveries	127	89	715	260
Net loans (charged-off) recovered	(353)	(284)	(6,051)	(951)
Ending balance	72,105	67,239	72,105	67,239
Unallocated
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	351	647	554	450
Provision for credit losses	98	(22)	(105)	175
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Net loans (charged-off) recovered	0	0	0	0
Ending balance	449	625	449	625
Commercial Portfolio Segment | Commercial and Industrial
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	30,978	31,195	35,290	30,595
Provision for credit losses	(167)	1,357	1,065	1,948
Loans charged-off	(193)	(222)	(5,844)	(254)
Recoveries	21	18	128	59
Net loans (charged-off) recovered	(172)	(204)	(5,716)	(195)
Ending balance	30,639	32,348	30,639	32,348
Commercial Portfolio Segment | Commercial Real Estate and Multifamily Residential
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	30,913	26,448	27,394	26,535
Provision for credit losses	230	(678)	3,465	(168)
Loans charged-off	0	0	0	(597)
Recoveries	12	25	296	25
Net loans (charged-off) recovered	12	25	296	(572)
Ending balance	31,155	25,795	31,155	25,795
Commercial Portfolio Segment | Agri-business and Agricultural
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	4,402	4,753	4,429	5,034
Provision for credit losses	(139)	(547)	(166)	(828)
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Net loans (charged-off) recovered	0	0	0	0
Ending balance	4,263	4,206	4,263	4,206
Commercial Portfolio Segment | Other Commercial
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,120	713	917	1,146
Provision for credit losses	(102)	16	101	(417)
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Net loans (charged-off) recovered	0	0	0	0
Ending balance	1,018	729	1,018	729
Consumer Portfolio Segment | Consumer 1-4 Family Mortgage
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,448	2,674	3,001	2,866
Provision for credit losses	197	(197)	642	(411)
Loans charged-off	(149)	(20)	(163)	(42)
Recoveries	3	3	19	47
Net loans (charged-off) recovered	(146)	(17)	(144)	5
Ending balance	3,499	2,460	3,499	2,460
Consumer Portfolio Segment | Other Consumer
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	846	1,093	1,021	1,147
Provision for credit losses	283	71	548	118
Loans charged-off	(138)	(131)	(759)	(318)
Recoveries	91	43	272	129
Net loans (charged-off) recovered	(47)	(88)	(487)	(189)
Ending balance	$ 1,082	$ 1,076	$ 1,082	$ 1,076