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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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