LOANS - Contractual Aging of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
LOANS
Loans current and past due less than 30 days	$ 1,563,091	$ 1,627,899
Loans receivable	1,575,708	1,644,209
Past Due 30-89 Days
LOANS
Loans past due	3,167	8,607
Past Due 90+ Days
LOANS
Loans past due	9,450	7,703
Commercial
LOANS
Loans current and past due less than 30 days	972,327	1,002,260
Loans receivable	979,309	1,007,751
Commercial \| Past Due 30-89 Days
LOANS
Loans past due	533	2,453
Commercial \| Past Due 90+ Days
LOANS
Loans past due	6,449	3,038
Commercial \| Real estate loan
LOANS
Loans current and past due less than 30 days	547,885	529,998
Loans receivable	553,389	531,810
Commercial \| Real estate loan \| Past Due 30-89 Days
LOANS
Loans past due	142	66
Commercial \| Real estate loan \| Past Due 90+ Days
LOANS
Loans past due	5,362	1,746
Commercial \| Commercial and industrial
LOANS
Loans current and past due less than 30 days	151,119	158,523
Loans receivable	152,244	159,577
Commercial \| Commercial and industrial \| Past Due 30-89 Days
LOANS
Loans past due	218	55
Commercial \| Commercial and industrial \| Past Due 90+ Days
LOANS
Loans past due	907	999
Commercial \| Paycheck Protection Program - 1st Draw
LOANS
Loans current and past due less than 30 days	5,747	132,269
Loans receivable	5,747	132,269
Commercial \| Paycheck Protection Program - 1st Draw \| Past Due 30-89 Days
LOANS
Loans past due	0	0
Commercial \| Paycheck Protection Program - 1st Draw \| Past Due 90+ Days
LOANS
Loans past due	0	0
Commercial \| Paycheck Protection Program - 2nd Draw
LOANS
Loans current and past due less than 30 days	56,981	0
Loans receivable	56,981	0
Commercial \| Paycheck Protection Program - 2nd Draw \| Past Due 30-89 Days
LOANS
Loans past due	0	0
Commercial \| Paycheck Protection Program - 2nd Draw \| Past Due 90+ Days
LOANS
Loans past due	0	0
Commercial \| Political subdivisions
LOANS
Loans current and past due less than 30 days	73,503	53,221
Loans receivable	73,503	53,221
Commercial \| Political subdivisions \| Past Due 30-89 Days
LOANS
Loans past due	0	0
Commercial \| Political subdivisions \| Past Due 90+ Days
LOANS
Loans past due	0	0
Commercial \| Construction Loans
LOANS
Loans current and past due less than 30 days	53,125	42,590
Loans receivable	53,267	42,874
Commercial \| Construction Loans \| Past Due 30-89 Days
LOANS
Loans past due	142	284
Commercial \| Construction Loans \| Past Due 90+ Days
LOANS
Loans past due	0	0
Commercial \| Loans secured by farm land
LOANS
Loans current and past due less than 30 days	10,667	11,419
Loans receivable	10,812	11,736
Commercial \| Loans secured by farm land \| Past Due 30-89 Days
LOANS
Loans past due	31	95
Commercial \| Loans secured by farm land \| Past Due 90+ Days
LOANS
Loans past due	114	222
Commercial \| Multi-family (5 or more) residential
LOANS
Loans current and past due less than 30 days	52,962	53,860
Loans receivable	52,962	55,811
Commercial \| Multi-family (5 or more) residential \| Past Due 30-89 Days
LOANS
Loans past due	0	1,951
Commercial \| Multi-family (5 or more) residential \| Past Due 90+ Days
LOANS
Loans past due	0	0
Commercial \| Agricultural loans
LOANS
Loans current and past due less than 30 days	3,026	3,091
Loans receivable	3,092	3,164
Commercial \| Agricultural loans \| Past Due 30-89 Days
LOANS
Loans past due	0	2
Commercial \| Agricultural loans \| Past Due 90+ Days
LOANS
Loans past due	66	71
Commercial \| Other commercial loans
LOANS
Loans current and past due less than 30 days	17,312	17,289
Loans receivable	17,312	17,289
Commercial \| Other commercial loans \| Past Due 30-89 Days
LOANS
Loans past due	0	0
Commercial \| Other commercial loans \| Past Due 90+ Days
LOANS
Loans past due	0	0
Residential mortgage
LOANS
Loans current and past due less than 30 days	573,317	609,576
Loans receivable	578,863	620,172
Residential mortgage \| Past Due 30-89 Days
LOANS
Loans past due	2,586	6,071
Residential mortgage \| Past Due 90+ Days
LOANS
Loans past due	2,960	4,525
Residential mortgage \| Real estate loan \| first liens
LOANS
Loans current and past due less than 30 days	489,339	523,191
Loans receivable	494,376	532,947
Residential mortgage \| Real estate loan \| first liens \| Past Due 30-89 Days
LOANS
Loans past due	2,212	5,703
Residential mortgage \| Real estate loan \| first liens \| Past Due 90+ Days
LOANS
Loans past due	2,825	4,053
Residential mortgage \| Real estate loan \| junior liens
LOANS
Loans current and past due less than 30 days	24,200	27,009
Loans receivable	24,303	27,311
Residential mortgage \| Real estate loan \| junior liens \| Past Due 30-89 Days
LOANS
Loans past due	32	111
Residential mortgage \| Real estate loan \| junior liens \| Past Due 90+ Days
LOANS
Loans past due	71	191
Residential mortgage \| Construction Loans
LOANS
Loans current and past due less than 30 days	21,719	20,457
Loans receivable	21,719	20,613
Residential mortgage \| Construction Loans \| Past Due 30-89 Days
LOANS
Loans past due	0	156
Residential mortgage \| Construction Loans \| Past Due 90+ Days
LOANS
Loans past due	0	0
Residential mortgage \| Home equity lines of credit
LOANS
Loans current and past due less than 30 days	38,059	38,919
Loans receivable	38,465	39,301
Residential mortgage \| Home equity lines of credit \| Past Due 30-89 Days
LOANS
Loans past due	342	101
Residential mortgage \| Home equity lines of credit \| Past Due 90+ Days
LOANS
Loans past due	64	281
Consumer
LOANS
Loans current and past due less than 30 days	17,447	16,063
Loans receivable	17,536	16,286
Consumer \| Past Due 30-89 Days
LOANS
Loans past due	48	83
Consumer \| Past Due 90+ Days
LOANS
Loans past due	$ 41	$ 140