LOANS, ALLOWANCE FOR LOAN LOSSES AND IMPAIRED LOANS - Troubled Debt Restructurings on Financing Receivables (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) contract TDR	Dec. 31, 2019 USD ($) contract TDR
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts | TDR	38	44
Pre-Modification Outstanding Recorded Investment	$ 12,746,000	$ 7,992,000
Post-Modification Outstanding Recorded Investment	12,746,000	7,992,000
Specific Reserve	$ 0	$ 458,054
Commercial/Agricultural real estate:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts | contract	12	18
Pre-Modification Outstanding Recorded Investment	$ 4,932,000	$ 5,411,000
Post-Modification Outstanding Recorded Investment	4,932,000	5,411,000
Specific Reserve	$ 0	$ 317,867
C&I/Agricultural operating:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts | contract	6	11
Pre-Modification Outstanding Recorded Investment	$ 6,373,000	$ 1,544,000
Post-Modification Outstanding Recorded Investment	6,373,000	1,544,000
Specific Reserve	$ 0	$ 98,152
Residential mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts | contract	17	14
Pre-Modification Outstanding Recorded Investment	$ 1,431,000	$ 1,035,000
Post-Modification Outstanding Recorded Investment	1,431,000	1,035,000
Specific Reserve	$ 0	$ 42,035
Consumer installment:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts | contract	3	1
Pre-Modification Outstanding Recorded Investment	$ 10,000	$ 2,000
Post-Modification Outstanding Recorded Investment	10,000	2,000
Specific Reserve	0	0
Modified Rate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	8,198,000	3,037,000
Modified Rate | Commercial/Agricultural real estate:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	4,441,000	2,028,000
Modified Rate | C&I/Agricultural operating:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	3,295,000	184,000
Modified Rate | Residential mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	456,000	823,000
Modified Rate | Consumer installment:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	6,000	2,000
Modified Payment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	1,134,000	523,000
Modified Payment | Commercial/Agricultural real estate:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	198,000	159,000
Modified Payment | C&I/Agricultural operating:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	78,000	364,000
Modified Payment | Residential mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	858,000	0
Modified Payment | Consumer installment:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	0	0
Modified Under- writing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	3,414,000	4,432,000
Modified Under- writing | Commercial/Agricultural real estate:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	293,000	3,224,000
Modified Under- writing | C&I/Agricultural operating:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	3,000,000	996,000
Modified Under- writing | Residential mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	117,000	212,000
Modified Under- writing | Consumer installment:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	4,000	0
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	0	0
Other | Commercial/Agricultural real estate:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	0	0
Other | C&I/Agricultural operating:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	0	0
Other | Residential mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	0	0
Other | Consumer installment:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan restructuring	$ 0	$ 0