LOANS AND ALLOWANCE FOR CREDIT LOSSES - Allowances For Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 22,517	$ 19,659	$ 19,659
Charge-offs	(367)	(383)	(1,383)
Recoveries	185	114
Net recoveries (charge-offs)	(182)	(269)
Provision (credit)	(1,864)	311
Ending balance	20,471	20,075	22,517
Cumulative effect adjustment for the adoption of ASC 326
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		374	374
Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		20,033	20,033
Commercial and Agricultural
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	5,055	3,373	3,373
Charge-offs	0	(190)
Recoveries	37	6
Net recoveries (charge-offs)	37	(184)
Provision (credit)	(576)	(45)
Ending balance	4,516	4,053	5,055
Commercial and Agricultural | Cumulative effect adjustment for the adoption of ASC 326
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		909	909
Commercial and Agricultural | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		4,282	4,282
Commercial Mortgages
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	12,026	11,576	11,576
Charge-offs	0	0
Recoveries	1	0
Net recoveries (charge-offs)	1	0
Provision (credit)	(1,660)	102
Ending balance	10,367	10,983	12,026
Commercial Mortgages | Cumulative effect adjustment for the adoption of ASC 326
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		(695)	(695)
Commercial Mortgages | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		10,881	10,881
Residential Mortgages
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	2,194	1,845	1,845
Charge-offs	(16)	0	(32)
Recoveries	22	0
Net recoveries (charge-offs)	6	0
Provision (credit)	(138)	63
Ending balance	2,062	1,892	2,194
Residential Mortgages | Cumulative effect adjustment for the adoption of ASC 326
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		(16)	(16)
Residential Mortgages | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		1,829	1,829
Consumer Loans
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,242	2,865	2,865
Charge-offs	(351)	(193)
Recoveries	125	108
Net recoveries (charge-offs)	(226)	(85)
Provision (credit)	510	191
Ending balance	3,526	3,147	3,242
Consumer Loans | Cumulative effect adjustment for the adoption of ASC 326
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		176	176
Consumer Loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance		3,041	3,041
Unfunded Loan Commitment
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	919	0	0
Provision (credit)	(176)	(34)
Ending balance	743	1,048	919
Unfunded Loan Commitment | Cumulative effect adjustment for the adoption of ASC 326
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 0	$ 1,082	1,082
Ending balance			$ 0