LOANS AND ALLOWANCE FOR LOAN LOSSES - Receivables Past Due (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	$ 18,008	$ 12,254
Loans Past Due 90 Days or More and Still Accruing	7	19
Past due	14,370	14,367
Loans Not Past Due	1,298,533	1,301,242
Total ending loans balance	1,312,903	1,315,609
30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	4,672	10,688
60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,668	1,207
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	8,029	2,472
Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	230,922	203,412
Commercial mortgages:
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	650,570	662,988
Residential Mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	2,155	2,655
Loans Past Due 90 Days or More and Still Accruing	0	0
Past due	2,775	3,746
Loans Not Past Due	186,099	179,479
Total ending loans balance	188,874	183,225
Residential Mortgages | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,016	2,204
Residential Mortgages | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	803	516
Residential Mortgages | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	956	1,026
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	242,537	265,984
Construction | Commercial mortgages:
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	80	109
Loans Past Due 90 Days or More and Still Accruing	0	0
Past due	0	0
Loans Not Past Due	44,082	54,626
Total ending loans balance	44,082	54,626
Construction | Commercial mortgages: | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Construction | Commercial mortgages: | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Construction | Commercial mortgages: | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Commercial mortgages | Commercial mortgages:
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	8,407	5,529
Loans Past Due 90 Days or More and Still Accruing	0	0
Past due	2,883	6,600
Loans Not Past Due	603,605	601,762
Total ending loans balance	606,488	608,362
Commercial mortgages | Commercial mortgages: | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	440	6,273
Commercial mortgages | Commercial mortgages: | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	277	158
Commercial mortgages | Commercial mortgages: | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,165	169
Credit cards | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Loans Past Due 90 Days or More and Still Accruing	0	9
Past due	0	13
Loans Not Past Due	0	1,437
Total ending loans balance	0	1,450
Credit cards | Consumer Loans | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	1
Credit cards | Consumer Loans | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	3
Credit cards | Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	9
Home equity lines and loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	641	1,183
Loans Past Due 90 Days or More and Still Accruing	0	0
Past due	653	1,106
Loans Not Past Due	91,412	97,360
Total ending loans balance	92,065	98,466
Home equity lines and loans | Consumer Loans | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	353	279
Home equity lines and loans | Consumer Loans | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	151	97
Home equity lines and loans | Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	149	730
Indirect Consumer Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	571	693
Loans Past Due 90 Days or More and Still Accruing	0	0
Past due	2,278	2,266
Loans Not Past Due	133,088	147,540
Total ending loans balance	135,366	149,806
Indirect Consumer Loans | Consumer Loans | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,546	1,511
Indirect Consumer Loans | Consumer Loans | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	377	319
Indirect Consumer Loans | Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	355	436
Direct consumer loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	7	37
Loans Past Due 90 Days or More and Still Accruing	0	0
Past due	49	204
Loans Not Past Due	15,057	16,058
Total ending loans balance	15,106	16,262
Direct consumer loans | Consumer Loans | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	32	120
Direct consumer loans | Consumer Loans | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	11	53
Direct consumer loans | Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	6	31
Commercial and industrial | Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	6,147	2,048
Loans Past Due 90 Days or More and Still Accruing	7	10
Past due	5,732	416
Loans Not Past Due	224,916	202,667
Total ending loans balance	230,648	203,083
Commercial and industrial | Commercial, and Agricultural | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,285	284
Commercial and industrial | Commercial, and Agricultural | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	49	61
Commercial and industrial | Commercial, and Agricultural | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	4,398	71
Agricultural | Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	16
Loans Not Past Due	274	313
Total ending loans balance	274	329
Agricultural | Commercial, and Agricultural | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	16
Agricultural | Commercial, and Agricultural | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
Agricultural | Commercial, and Agricultural | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	$ 0	$ 0