LOANS AND ALLOWANCE FOR LOAN LOSSES - Receivables Past Due (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	$ 12,254	$ 17,324
Loans Past Due 90 Days or More and Still Accruing	19	29
Past Due	14,367	14,076
Loans Not Past Due	1,301,242	1,300,714
Total ending loans balance	1,315,609	1,315,582
30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,688	7,639
60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,207	2,605
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,472	3,832
Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	203,412	199,576
Commercial mortgages:
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	662,988	646,174
Residential Mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	2,655	3,160
Loans Past Due 90 Days or More and Still Accruing	0	0
Past Due	3,746	3,812
Loans Not Past Due	179,479	191,125
Total ending loans balance	183,225	194,937
Residential Mortgages | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,204	1,399
Residential Mortgages | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	516	939
Residential Mortgages | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,026	1,474
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	265,984	274,895
Construction | Commercial mortgages:
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	109	135
Loans Past Due 90 Days or More and Still Accruing	0	0
Past Due	0	0
Loans Not Past Due	54,626	45,688
Total ending loans balance	54,626	45,688
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	5,529	6,520
Loans Past Due 90 Days or More and Still Accruing	0	0
Past Due	6,600	3,262
Loans Not Past Due	601,762	596,432
Total ending loans balance	608,362	600,486
Commercial mortgages | Commercial mortgages: | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	6,273	2,399
Commercial mortgages | Commercial mortgages: | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	158	115
Commercial mortgages | Commercial mortgages: | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	169	748
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	9	24
Past Due	13	50
Loans Not Past Due	1,437	1,466
Total ending loans balance	1,450	1,516
Credit cards | Consumer Loans | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1	17
Credit cards | Consumer Loans | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3	9
Credit cards | Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	9	24
Home equity lines and loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	1,183	1,310
Loans Past Due 90 Days or More and Still Accruing	0	0
Past Due	1,106	1,279
Loans Not Past Due	97,360	99,599
Total ending loans balance	98,466	100,878
Home equity lines and loans | Consumer Loans | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	279	265
Home equity lines and loans | Consumer Loans | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	97	31
Home equity lines and loans | Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	730	983
Indirect Consumer Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	693	935
Loans Past Due 90 Days or More and Still Accruing	0	0
Past Due	2,266	2,887
Loans Not Past Due	147,540	150,645
Total ending loans balance	149,806	153,532
Indirect Consumer Loans | Consumer Loans | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,511	1,822
Indirect Consumer Loans | Consumer Loans | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	319	484
Indirect Consumer Loans | Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	436	581
Direct consumer loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	37	14
Loans Past Due 90 Days or More and Still Accruing	0	0
Past Due	204	78
Loans Not Past Due	16,058	18,891
Total ending loans balance	16,262	18,969
Direct consumer loans | Consumer Loans | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	120	48
Direct consumer loans | Consumer Loans | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	53	28
Direct consumer loans | Consumer Loans | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	31	2
Loans acquired with deteriorated credit quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	792
Total ending loans balance	0	792
Loans acquired with deteriorated credit quality | Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	0	0
Loans acquired with deteriorated credit quality | Commercial mortgages:
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	0	792
Loans acquired with deteriorated credit quality | Residential Mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Total ending loans balance	0	0
Loans acquired with deteriorated credit quality | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total ending loans balance	0	0
Loans acquired with deteriorated credit quality | Construction | Commercial mortgages:
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Total ending loans balance	0	0
Loans acquired with deteriorated credit quality | Commercial mortgages | Commercial mortgages:
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	792
Total ending loans balance	0	792
Loans acquired with deteriorated credit quality | Credit cards | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Total ending loans balance	0	0
Loans acquired with deteriorated credit quality | Home equity lines and loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Total ending loans balance	0	0
Loans acquired with deteriorated credit quality | Indirect Consumer Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Total ending loans balance	0	0
Loans acquired with deteriorated credit quality | Direct consumer loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Total ending loans balance	0	0
Commercial and industrial | Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	2,048	5,250
Loans Past Due 90 Days or More and Still Accruing	10	5
Past Due	416	2,708
Loans Not Past Due	202,667	196,322
Total ending loans balance	203,083	199,030
Commercial and industrial | Commercial, and Agricultural | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	284	1,689
Commercial and industrial | Commercial, and Agricultural | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	61	999
Commercial and industrial | Commercial, and Agricultural | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	71	20
Commercial and industrial | Loans acquired with deteriorated credit quality | Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Total ending loans balance	0	0
Agricultural | Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	16	0
Loans Not Past Due	313	546
Total ending loans balance	329	546
Agricultural | Commercial, and Agricultural | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	16	0
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
Agricultural | Loans acquired with deteriorated credit quality | Commercial, and Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual	0	0
Total ending loans balance	$ 0	$ 0