LOANS, ALLOWANCE FOR LOAN LOSSES AND IMPAIRED LOANS - Loans by Loan Segment (Details) $ in Thousands	6 Months Ended			12 Months Ended
	Jun. 30, 2020 USD ($) TDR	Jun. 30, 2020 USD ($) Contract	Jun. 30, 2019 USD ($) Contract	Dec. 31, 2019 USD ($) TDR
Troubled Debt Restructuring
Number of Modifications	1	19	21	0
Recorded Investment | $	$ 13,119	$ 13,119		$ 12,594
Commercial/agriculture real estate
Troubled Debt Restructuring
Number of Modifications		9	7
C&I/Agricultural operating
Troubled Debt Restructuring
Number of Modifications		3	6
Residential mortgage
Troubled Debt Restructuring
Number of Modifications		5	7
Consumer installment
Troubled Debt Restructuring
Number of Modifications		2	1
Originated Loans
Troubled Debt Restructuring
Number of Modifications		102	90
Recorded Investment | $	13,119	$ 13,119	$ 10,000
Originated Loans | Commercial/agriculture real estate
Troubled Debt Restructuring
Number of Modifications		34	20
Recorded Investment | $	7,140	$ 7,140	$ 3,938
Originated Loans | C&I/Agricultural operating
Troubled Debt Restructuring
Number of Modifications		17	16
Recorded Investment | $	2,580	$ 2,580	$ 2,469
Originated Loans | Residential mortgage
Troubled Debt Restructuring
Number of Modifications		43	43
Recorded Investment | $	3,336	$ 3,336	$ 3,511
Originated Loans | Consumer installment
Troubled Debt Restructuring
Number of Modifications		8	11
Recorded Investment | $	$ 63	$ 63	$ 82