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LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowances (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	$ 21,025	$ 20,924
Charge-offs	(198)	(190)
Recoveries	246	434
Net recoveries (charge-offs)	48	244
Provision	(1,145)	(259)
Ending balance	19,928	20,909
Ending allowance balance attributable to loans:
Individually evaluated for impairment	2,861		$ 3,030
Collectively evaluated for impairment	17,067		17,995
Total ending allowance balance	19,928	20,909	21,025
Loans:
Loans individually evaluated for impairment	10,403		11,647
Loans collectively evaluated for  impairment	1,560,456		1,510,735
Total recorded investment in loans	1,570,859		1,522,382
Commercial and Agricultural
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	3,591	4,493
Charge-offs	(4)	0
Recoveries	6	296
Net recoveries (charge-offs)	2	296
Provision	(110)	(452)
Ending balance	3,483	4,337
Ending allowance balance attributable to loans:
Individually evaluated for impairment	1,329		1,394
Collectively evaluated for impairment	2,154		2,197
Total ending allowance balance	3,483	4,337	3,591
Loans:
Loans individually evaluated for impairment	2,341		2,427
Loans collectively evaluated for  impairment	252,677		255,586
Total recorded investment in loans	255,018		258,013
Commercial Mortgages
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	13,556	11,496
Charge-offs	0	0
Recoveries	1	0
Net recoveries (charge-offs)	1	0
Provision	(593)	290
Ending balance	12,964	11,786
Ending allowance balance attributable to loans:
Individually evaluated for impairment	1,479		1,571
Collectively evaluated for impairment	11,485		11,985
Total ending allowance balance	12,964	11,786	13,556
Loans:
Loans individually evaluated for impairment	6,829		7,967
Loans collectively evaluated for  impairment	843,645		796,858
Total recorded investment in loans	850,474		804,825
Residential Mortgages
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	1,803	2,079
Charge-offs	0	(26)
Recoveries	0	0
Net recoveries (charge-offs)	0	(26)
Provision	(197)	62
Ending balance	1,606	2,115
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	1,606		1,803
Total ending allowance balance	1,606	2,115	1,803
Loans:
Loans individually evaluated for impairment	931		938
Loans collectively evaluated for  impairment	264,555		259,029
Total recorded investment in loans	265,486		259,967
Consumer Loans
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	2,075	2,856
Charge-offs	(194)	(164)
Recoveries	239	138
Net recoveries (charge-offs)	45	(26)
Provision	(245)	(159)
Ending balance	1,875	2,671
Ending allowance balance attributable to loans:
Individually evaluated for impairment	53		65
Collectively evaluated for impairment	1,822		2,010
Total ending allowance balance	1,875	$ 2,671	2,075
Loans:
Loans individually evaluated for impairment	302		315
Loans collectively evaluated for  impairment	199,579		199,262
Total recorded investment in loans	$ 199,881		$ 199,577

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