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LOANS AND ALLOWANCE FOR LOAN LOSSES - Impaired Loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017
Unpaid Principal Balance [Abstract] |  |  |  |  |
Unpaid principal balance, total | $ 9,270 |  | $ 9,270 |  | $ 14,094
Recorded Investment [Abstract] |  |  |  |  |
Recorded investment, total | 9,221 |  | 9,221 |  | 13,926
Allowance for loan losses allocated | 2,209 |  | 2,209 |  | 5,937
Average Recorded Investment [Abstract] |  |  |  |  |
Average recorded investment, total | 9,280 | $ 12,100 | 11,533 | $ 12,391 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
Interest income, accrual method, total | 14 | 26 | 49 | 128 |
Commercial Mortgages | Construction |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, Unpaid Principal Balance | 322 |  | 322 |  | 364
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 323 |  | 323 |  | 365
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 330 | 974 | 344 | 946 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 3 | 3 | 8 | 9 |
Commercial Mortgages | Commercial mortgages, other |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, Unpaid Principal Balance | 4,342 |  | 4,342 |  | 4,135
With related allowance, Unpaid Principal Balance | 1,939 |  | 1,939 |  | 2,989
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 4,309 |  | 4,309 |  | 4,138
With related allowance, Recorded Investment | 1,940 |  | 1,940 |  | 2,799
Allowance for loan losses allocated | 496 |  | 496 |  | 802
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 4,339 | 4,946 | 4,257 | 5,973 |
With related allowance, Average Recorded Investment | 2,040 | 4,721 | 2,419 | 3,989 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 5 | 5 | 16 | 73 |
With related allowance, Interest Income, Accrual Method | 1 | 4 | 4 | 10 |
Residential mortgages |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, Unpaid Principal Balance | 432 |  | 432 |  | 450
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 410 |  | 410 |  | 427
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 413 | 439 | 420 | 416 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 2 | 2 | 6 | 6 |
Consumer Loans | Home equity lines and loans |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, Unpaid Principal Balance | 57 |  | 57 |  | 64
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 58 |  | 58 |  | 64
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 59 | 68 | 61 | 76 |
With related allowance, Average Recorded Investment | 0 | 0 | 0 | 180 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 1 | 1 | 2 | 2 |
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 | 405 |  | 405 |  | 861
With related allowance, Unpaid Principal Balance | 1,773 |  | 1,773 |  | 5,231
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 405 |  | 405 |  | 867
With related allowance, Recorded Investment | 1,776 |  | 1,776 |  | 5,266
Allowance for loan losses allocated | 1,713 |  | 1,713 |  | $ 5,135
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 526 | 661 | 673 | 666 |
With related allowance, Average Recorded Investment | 1,573 | 291 | 3,359 | 145 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 1 | 8 | 11 | 24 |
With related allowance, Interest Income, Accrual Method | $ 1 | $ 3 | $ 2 | $ 4 |

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