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LOANS AND ALLOWANCE FOR LOAN LOSSES - Impaired Loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Dec. 31, 2019
Unpaid Principal Balance [Abstract] |  |  |  |  |
Unpaid principal balance, total | $ 17,915 |  | $ 17,915 |  | $ 15,712
Recorded Investment [Abstract] |  |  |  |  |
Recorded investment, total | 15,741 |  | 15,741 |  | 15,665
Allowance for loan losses allocated | 5,706 |  | 5,706 |  | 8,097
Average Recorded Investment [Abstract] |  |  |  |  |
Average recorded investment, total | 15,420 | $ 14,323 | 15,501 | $ 12,459 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
Interest income, accrual method, total | 19 | 8 | 27 | 17 |
Commercial Mortgages | Construction |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 219 |  | 219 |  | 247
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 220 |  | 220 |  | 247
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 226 | 285 | 233 | 293 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 2 | 2 | 4 | 5 |
Commercial Mortgages | Commercial mortgages, other |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 6,887 |  | 6,887 |  | 3,501
With related allowance, Unpaid Principal Balance | 2,197 |  | 2,197 |  | 5,093
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 4,743 |  | 4,743 |  | 3,503
With related allowance, recorded investment | 2,199 |  | 2,199 |  | 5,094
Allowance for loan losses allocated | 213 |  | 213 |  | 2,097
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 3,982 | 3,640 | 3,822 | 3,738 |
With related allowance, average recorded investment | 3,613 | 7,741 | 4,107 | 5,795 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 0 | 3 | 0 | 6 |
With related allowance, interest income, accrual method | 8 | 0 | 8 | 0 |
Residential mortgages |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 1,190 |  | 1,190 |  | 554
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 1,170 |  | 1,170 |  | 525
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 844 | 388 | 738 | 393 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 5 | 2 | 10 | 4 |
Consumer Loans | Home equity lines and loans |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 672 |  | 672 |  | 171
With related allowance, Unpaid Principal Balance | 180 |  | 180 |  | 0
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 657 |  | 657 |  | 149
With related allowance, recorded investment | 180 |  | 180 |  | 0
Allowance for loan losses allocated | 62 |  | 62 |  | 0
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 403 | 163 | 318 | 127 |
With related allowance, average recorded investment | 90 | 0 | 60 | 0 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 2 | 1 | 3 | 1 |
With related allowance, interest income, accrual method | 0 | 0 | 0 | 0 |
Commercial and industrial | Commercial and agricultural |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 1,089 |  | 1,089 |  | 133
With related allowance, Unpaid Principal Balance | 5,481 |  | 5,481 |  | 6,013
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 1,088 |  | 1,088 |  | 133
With related allowance, recorded investment | 5,484 |  | 5,484 |  | 6,014
Allowance for loan losses allocated | 5,431 |  | 5,431 |  | $ 6,000
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 597 | 289 | 442 | 308 |
With related allowance, average recorded investment | 5,665 | 1,817 | 5,781 | 1,805 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 0 | 0 | 0 | 1 |
With related allowance, interest income, accrual method | $ 2 | $ 0 | $ 2 | $ 0 |

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