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LOANS AND ALLOWANCE FOR LOAN LOSSES - Troubled Debt Restructuring (Details) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2018 USD ($) contract | Sep. 30, 2017 USD ($) loan contract | Sep. 30, 2018 USD ($) loan contract | Sep. 30, 2017 USD ($) loan contract | Dec. 31, 2017 USD ($)
Troubled Debt Restructurings [Abstract] |  |  |  |  |
Recorded investment in troubled debt restructurings | $ 6,600,000 |  | $ 6,600,000 |  | $ 7,700,000
Troubled debt restructuring reserve | 500,000 |  | 500,000 |  | 700,000
Troubled debt restructurings accruing interest under modified terms | 900,000 |  | 900,000 |  | 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 |
Extension of maturity date |  |  |  | 5 years |
Allowance for loan losses |  | $ 100,000 |  | $ 200,000 |
TDR charge-offs |  | $ 0 |  | $ 0 |
Loans by class modified as troubled debt restructurings [Abstract] |  |  |  |  |
Number of loans | loan |  | 2 | 1 | 5 |
Pre-modification outstanding recorded investment |  | $ 506,000 | $ 100,000 | $ 948,000 |
Post-modification outstanding recorded investment |  | $ 506,000 | $ 100,000 | $ 948,000 |
Residential mortgages |  |  |  |  |
Loans by class modified as troubled debt restructurings [Abstract] |  |  |  |  |
Number of loans | loan |  |  |  | 1 |
Pre-modification outstanding recorded investment |  |  |  | $ 105,000 |
Post-modification outstanding recorded investment |  |  |  | $ 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 |  | 2 | 1 | 3 |
Pre-modification outstanding recorded investment |  | $ 506,000 | $ 100,000 | $ 677,000 |
Post-modification outstanding recorded investment |  | $ 506,000 | $ 100,000 | $ 677,000 |
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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