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LOANS AND ALLOWANCE FOR LOAN LOSSES - Troubled Debt Restructuring (Details) | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2018 USD ($) contract loan | Jun. 30, 2017 USD ($) contract loan | Jun. 30, 2018 USD ($) contract loan | Jun. 30, 2017 USD ($) contract loan | Dec. 31, 2017 USD ($)
Troubled Debt Restructurings [Abstract] |  |  |  |  |
Recorded investment in troubled debt restructurings | $ 7,100,000 |  | $ 7,100,000 |  | $ 7,700,000
Troubled debt restructuring reserve | 500,000 |  | 500,000 |  | 700,000
Troubled debt restructurings accruing interest under modified terms | 1,400,000 |  | 1,400,000 |  | 1,700,000
Troubled debt restructurings on non-accrual status | 5,700,000 |  | 5,700,000 |  | 6,000,000
Additional amounts committed to customers with loans classified as troubled debt restructurings | $ 0 |  | $ 0 |  | $ 0
Number of loans | contract | 0 | 0 | 0 | 0 |
Allowance for loan losses |  | $ 100,000 |  | $ 100,000 |
TDR charge-offs |  | $ 0 |  | $ 0 |
Loans by class modified as troubled debt restructurings [Abstract] |  |  |  |  |
Number of loans | loan |  | 4 | 1 | 5 |
Pre-modification outstanding recorded investment |  | $ 276,000 | $ 100,000 | $ 442,000 |
Post-modification outstanding recorded investment |  | $ 276,000 | $ 100,000 | $ 442,000 |
Residential mortgages |  |  |  |  |
Loans by class modified as troubled debt restructurings [Abstract] |  |  |  |  |
Number of loans | loan |  | 1 |  | 1 |
Pre-modification outstanding recorded investment |  | $ 105,000 |  | $ 105,000 |
Post-modification outstanding recorded investment |  | $ 105,000 |  | $ 105,000 |
Commercial and industrial |  |  |  |  |
Troubled Debt Restructurings [Abstract] |  |  |  |  |
Number of loans | loan | 1 |  |  |  |
Commercial and industrial | Commercial and agricultural: |  |  |  |  |
Loans by class modified as troubled debt restructurings [Abstract] |  |  |  |  |
Number of loans | loan |  | 3 | 1 | 3 |
Pre-modification outstanding recorded investment |  | $ 171,000 | $ 100,000 | $ 171,000 |
Post-modification outstanding recorded investment |  | $ 171,000 | $ 100,000 | $ 171,000 |
Commercial mortgages |  |  |  |  |
Troubled Debt Restructurings [Abstract] |  |  |  |  |
Number of loans | loan |  | 1 |  |  |
Commercial mortgages | Commercial Mortgages |  |  |  |  |
Loans by class modified as troubled debt restructurings [Abstract] |  |  |  |  |
Number of loans | loan |  |  |  | 1 |
Pre-modification outstanding recorded investment |  |  |  | $ 166,000 |
Post-modification outstanding recorded investment |  |  |  | $ 166,000 |

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