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LOANS AND ALLOWANCE FOR LOAN LOSSES - Impaired Loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018
Unpaid Principal Balance [Abstract] |  |  |  |  |
Unpaid principal balance, total | $ 20,748 |  | $ 20,748 |  | $ 8,819
Recorded Investment [Abstract] |  |  |  |  |
Recorded investment, total | 20,617 |  | 20,617 |  | 8,731
Allowance for loan losses allocated | 8,660 |  | 8,660 |  | 2,189
Average Recorded Investment [Abstract] |  |  |  |  |
Average recorded investment, total | 18,645 | $ 9,280 | 14,111 | $ 11,533 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
Interest income, accrual method, total | 44 | 14 | 61 | 49 |
Commercial Mortgages | Construction |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 262 |  | 262 |  | 307
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 263 |  | 263 |  | 308
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 270 | 330 | 285 | 344 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 2 | 3 | 7 | 8 |
Commercial Mortgages | Commercial mortgages, other |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 3,305 |  | 3,305 |  | 4,007
With related allowance, Unpaid Principal Balance | 10,221 |  | 10,221 |  | 1,902
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 3,306 |  | 3,306 |  | 3,935
With related allowance, recorded investment | 10,139 |  | 10,139 |  | 1,903
Allowance for loan losses allocated | 2,519 |  | 2,519 |  | 446
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 3,372 | 4,339 | 3,630 | 4,257 |
With related allowance, average recorded investment | 10,240 | 2,040 | 6,881 | 2,419 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 3 | 5 | 9 | 16 |
With related allowance, interest income, accrual method | 0 | 1 | 0 | 4 |
Residential mortgages |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 436 |  | 436 |  | 424
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 407 |  | 407 |  | 402
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 396 | 413 | 396 | 420 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 36 | 2 | 40 | 6 |
Consumer Loans | Home equity lines and loans |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 176 |  | 176 |  | 54
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 153 |  | 153 |  | 55
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 156 | 59 | 134 | 61 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 3 | 1 | 4 | 2 |
Commercial and industrial | Commercial and agricultural |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, unpaid principal balance | 184 |  | 184 |  | 345
With related allowance, Unpaid Principal Balance | 6,164 |  | 6,164 |  | 1,780
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, recorded investment | 184 |  | 184 |  | 346
With related allowance, recorded investment | 6,165 |  | 6,165 |  | 1,782
Allowance for loan losses allocated | 6,141 |  | 6,141 |  | $ 1,743
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, average recorded investment | 228 | 526 | 277 | 673 |
With related allowance, average recorded investment | 3,983 | 1,573 | 2,508 | 3,359 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, interest income, accrual method | 0 | 1 | 1 | 11 |
With related allowance, interest income, accrual method | $ 0 | $ 1 | $ 0 | $ 2 |

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