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LOANS AND ALLOWANCE FOR LOAN LOSSES - Summary of Impaired Loans (Details) - USD ($) $ in Thousands | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded | $ 8,468 |  | $ 5,717
Unpaid Principal Balance, With related allowance recorded | 1,291 |  | 623
Unpaid Principal Balance | 9,759 |  | 6,340
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded | 8,468 |  | 5,717
Recorded Investment, With related allowance recorded | 1,291 |  | 623
Recorded Investment | 9,759 |  | 6,340
Related Allowance [Abstract] |  |  |
Related Allowance | 345 |  | 134
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded | 3,319 |  | 6,786
Average Recorded Investment, With related allowance recorded | 421 |  | 1,953
Average Recorded Investment | 3,740 |  | 8,739
Interest income | 0 | $ 0 |
Cash-based interest income | 0 | $ 0 |
Commercial and industrial |  |  |
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded | 684 |  | 437
Unpaid Principal Balance, With related allowance recorded | 392 |  | 26
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded | 684 |  | 437
Recorded Investment, With related allowance recorded | 392 |  | 26
Related Allowance [Abstract] |  |  |
Related Allowance | 209 |  | 17
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded | 331 |  | 434
Average Recorded Investment, With related allowance recorded | 58 |  | 315
Construction and development |  |  |
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded |  |  | 0
Unpaid Principal Balance, With related allowance recorded |  |  | 0
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded |  |  | 0
Recorded Investment, With related allowance recorded |  |  | 0
Related Allowance [Abstract] |  |  |
Related Allowance |  |  | 0
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded |  |  | 311
Average Recorded Investment, With related allowance recorded |  |  | 7
Commercial real estate |  |  |
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded | 6,024 |  | 3,979
Unpaid Principal Balance, With related allowance recorded | 506 |  | 279
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded | 6,024 |  | 3,979
Recorded Investment, With related allowance recorded | 506 |  | 279
Related Allowance [Abstract] |  |  |
Related Allowance | 49 |  | 27
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded | 2,196 |  | 4,230
Average Recorded Investment, With related allowance recorded | 188 |  | 505
Farmland |  |  |
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded | 73 |  | 6
Unpaid Principal Balance, With related allowance recorded | 149 |  | 157
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded | 73 |  | 6
Recorded Investment, With related allowance recorded | 149 |  | 157
Related Allowance [Abstract] |  |  |
Related Allowance | 78 |  | 85
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded | 32 |  | 90
Average Recorded Investment, With related allowance recorded | 75 |  | 131
1-4 family residential |  |  |
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded | 1,194 |  | 681
Unpaid Principal Balance, With related allowance recorded | 244 |  | 161
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded | 1,194 |  | 681
Recorded Investment, With related allowance recorded | 244 |  | 161
Related Allowance [Abstract] |  |  |
Related Allowance | 9 |  | 5
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded | 470 |  | 1,096
Average Recorded Investment, With related allowance recorded | 48 |  | 754
Multi-family residential |  |  |
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded | 0 |  | 217
Unpaid Principal Balance, With related allowance recorded |  |  | 0
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded | 0 |  | 217
Recorded Investment, With related allowance recorded |  |  | 0
Related Allowance [Abstract] |  |  |
Related Allowance |  |  | 0
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded | 53 |  | 180
Average Recorded Investment, With related allowance recorded |  |  | 19
Consumer |  |  |
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded |  |  | 0
Unpaid Principal Balance, With related allowance recorded |  |  | 0
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded |  |  | 0
Recorded Investment, With related allowance recorded |  |  | 0
Related Allowance [Abstract] |  |  |
Related Allowance |  |  | 0
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded |  |  | 61
Average Recorded Investment, With related allowance recorded |  |  | 42
Agricultural |  |  |
Unpaid Principal Balance [Abstract] |  |  |
Unpaid Principal Balance, With no related allowance recorded | 493 |  | 397
Unpaid Principal Balance, With related allowance recorded | 0 |  | 0
Recorded Investment [Abstract] |  |  |
Recorded Investment, With no related allowance recorded | 493 |  | 397
Recorded Investment, With related allowance recorded | 0 |  | 0
Related Allowance [Abstract] |  |  |
Related Allowance | 0 |  | 0
Average Recorded Investment [Abstract] |  |  |
Average Recorded Investment, With no related allowance recorded | 237 |  | 384
Average Recorded Investment, With related allowance recorded | $ 52 |  | $ 180

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