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LOANS AND ALLOWANCE FOR LOAN LOSSES - Impaired Loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016 | Dec. 31, 2016
Unpaid Principal Balance [Abstract] |  |  |  |  |
Unpaid principal balance, total | $ 14,091 |  | $ 14,091 |  | $ 12,852
Recorded Investment [Abstract] |  |  |  |  |
Recorded investment, total | 13,108 |  | 13,108 |  | 11,926
Allowance for loan losses allocated | 970 |  | 970 |  | 876
Average Recorded Investment [Abstract] |  |  |  |  |
Average recorded investment, total | 13,273 | $ 13,932 | 12,825 | $ 14,280 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
Interest income, accrual method, total | 51 | 77 | 126 | 160 |
Commercial Mortgages | Construction |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, Unpaid Principal Balance | 1,550 |  | 1,550 |  | 277
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 1,551 |  | 1,551 |  | 278
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 1,555 | 340 | 1,130 | 343 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 3 | 3 | 6 | 7 |
Commercial Mortgages | Commercial mortgages, other |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, Unpaid Principal Balance | 5,641 |  | 5,641 |  | 8,792
With related allowance, Unpaid Principal Balance | 5,595 |  | 5,595 |  | 2,245
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 5,615 |  | 5,615 |  | 7,857
With related allowance, Recorded Investment | 4,657 |  | 4,657 |  | 2,247
Allowance for loan losses allocated | 886 |  | 886 |  | 735
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 5,879 | 6,733 | 6,538 | 7,014 |
With related allowance, Average Recorded Investment | 4,461 | 4,942 | 3,723 | 4,910 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 32 | 59 | 90 | 121 |
With related allowance, Interest Income, Accrual Method | 4 | 1 | 7 | 3 |
Residential mortgages |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, Unpaid Principal Balance | 466 |  | 466 |  | 395
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 443 |  | 443 |  | 396
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 417 | 399 | 410 | 344 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 2 | 1 | 4 | 1 |
Consumer loans: | Home equity lines and loans |  |  |  |  |
Unpaid Principal Balance [Abstract] |  |  |  |  |
With no related allowance, Unpaid Principal Balance | 69 |  | 69 |  | 93
With related allowance, Unpaid Principal Balance | 0 |  | 0 |  | 360
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 70 |  | 70 |  | 95
With related allowance, Recorded Investment | 0 |  | 0 |  | 360
Allowance for loan losses allocated | 0 |  | 0 |  | 141
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 71 | 104 | 79 | 105 |
With related allowance, Average Recorded Investment | 180 | 362 | 240 | 363 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 1 | 1 | 1 | 3 |
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 | 602 |  | 602 |  | 690
With related allowance, Unpaid Principal Balance | 168 |  | 168 |  | 0
Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Recorded Investment | 604 |  | 604 |  | 693
With related allowance, Recorded Investment | 168 |  | 168 |  | 0
Allowance for loan losses allocated | 84 |  | 84 |  | $ 0
Average Recorded Investment [Abstract] |  |  |  |  |
With no related allowance, Average Recorded Investment | 626 | 1,048 | 649 | 1,195 |
With related allowance, Average Recorded Investment | 84 | 4 | 56 | 6 |
Interest Income, Accrual Method [Abstract] |  |  |  |  |
With no related allowance, Interest Income, Accrual Method | 8 | 12 | 17 | 25 |
With related allowance, Interest Income, Accrual Method | $ 1 | $ 0 | $ 1 | $ 0 |

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