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LOANS AND ALLOWANCE FOR LOAN LOSSES - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Unpaid Principal Balance [Abstract]
Unpaid principal balance, total	$ 16,779		$ 16,779		$ 8,819
Recorded Investment [Abstract]
Recorded investment, total	16,675		16,675		8,731
Allowance for loan losses allocated	4,464		4,464		2,189
Average Recorded Investment [Abstract]
Average recorded investment, total	14,323	$ 11,490	12,459	$ 12,303
Interest Income, Accrual Method [Abstract]
Interest income, accrual method, total	8	19	17	40
Commercial Mortgages | Construction
Unpaid Principal Balance [Abstract]
With no related allowance, unpaid principal balance	277		277		307
Recorded Investment [Abstract]
With no related allowance, recorded investment	278		278		308
Average Recorded Investment [Abstract]
With no related allowance, average recorded investment	285	345	293	352
Interest Income, Accrual Method [Abstract]
With no related allowance, interest income, accrual method	2	3	5	6
Commercial Mortgages | Commercial mortgages, other
Unpaid Principal Balance [Abstract]
With no related allowance, unpaid principal balance	3,436		3,436		4,007
With related allowance, Unpaid Principal Balance	10,423		10,423		1,902
Recorded Investment [Abstract]
With no related allowance, recorded investment	3,438		3,438		3,935
With related allowance, recorded investment	10,340		10,340		1,903
Allowance for loan losses allocated	2,738		2,738		446
Average Recorded Investment [Abstract]
With no related allowance, average recorded investment	3,640	4,290	3,738	4,240
With related allowance, average recorded investment	7,741	2,467	5,795	2,578
Interest Income, Accrual Method [Abstract]
With no related allowance, interest income, accrual method	3	5	6	10
With related allowance, interest income, accrual method	0	1	0	3
Residential mortgages
Unpaid Principal Balance [Abstract]
With no related allowance, unpaid principal balance	413		413		424
Recorded Investment [Abstract]
With no related allowance, recorded investment	385		385		402
Average Recorded Investment [Abstract]
With no related allowance, average recorded investment	388	421	393	423
Interest Income, Accrual Method [Abstract]
With no related allowance, interest income, accrual method	2	2	4	4
Consumer Loans | Home equity lines and loans
Unpaid Principal Balance [Abstract]
With no related allowance, unpaid principal balance	158		158		54
Recorded Investment [Abstract]
With no related allowance, recorded investment	160		160		55
Average Recorded Investment [Abstract]
With no related allowance, average recorded investment	163	61	127	62
Interest Income, Accrual Method [Abstract]
With no related allowance, interest income, accrual method	1	1	1	2
Commercial and industrial | Commercial and agricultural
Unpaid Principal Balance [Abstract]
With no related allowance, unpaid principal balance	272		272		345
With related allowance, Unpaid Principal Balance	1,800		1,800		1,780
Recorded Investment [Abstract]
With no related allowance, recorded investment	273		273		346
With related allowance, recorded investment	1,801		1,801		1,782
Allowance for loan losses allocated	1,726		1,726		$ 1,743
Average Recorded Investment [Abstract]
With no related allowance, average recorded investment	289	710	308	762
With related allowance, average recorded investment	1,817	3,196	1,805	3,886
Interest Income, Accrual Method [Abstract]
With no related allowance, interest income, accrual method	0	7	1	15
With related allowance, interest income, accrual method	$ 0	$ 0	$ 0	$ 0

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