LOANS AND ALLOWANCE FOR CREDIT LOSSES - Collateral Dependent (Details) - USD ($) $ in Thousands	Jun. 30, 2023		Mar. 31, 2023	Dec. 31, 2022		Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	$ 5,937			$ 7,482
Related Allowance	20,172	[1]	$ 20,075	19,659	[1]	$ 17,485	$ 19,928	$ 21,025
Commercial and Agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	1,714			2,112
Related Allowance	4,121		4,053	3,373		3,564	3,485	3,591
Commercial Mortgages
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	3,964			4,383
Related Allowance	10,994		10,983	11,576		10,314	12,963	13,556
Consumer Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	259			264
Related Allowance	3,152		$ 3,147	$ 2,865		$ 1,893	$ 1,874	$ 2,075
Collateral Pledged
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	5,096
Related Allowance	250
Commercial Real Estate And Business Assets | Commercial and Agricultural | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	570
Related Allowance	156
Commercial Real Estate | Commercial Mortgages | Commercial mortgages, other
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	4,267
Related Allowance	33
Residential Real Estate | Consumer Loans | Home equity lines and loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Amortized Cost Basis	259
Related Allowance	$ 61

[1] Effective January 1, 2023, the allowance calculation is based upon Current Expected Credit loss methodology. Prior to January 1, 2023, the allowance calculation was based upon incurred loss methodology. Refer to Note 1 for further discussion.