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SUBORDINATED DEBENTURES - Narrative (Details) - USD ($) | 1 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Jul. 31, 2019 | Jul. 31, 2018 | Jul. 31, 2017 | May 31, 2017 | Jun. 30, 2019 | Dec. 31, 2015 | Jul. 31, 2015
Debt Instrument [Line Items] |  |  |  |  |  |  |
Liquidation value per share |  |  |  |  | $ 1,000 |  |
Debentures mature date |  |  |  |  | 30 years |  |
Subordinated debentures | Trust II Debentures |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debenture issued |  |  |  |  | $ 3,093,000 |  |
Subordinated debentures | Trust II Debentures | Minimum |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notice period required for redemption of debentures |  |  |  |  | 30 days |  |
Subordinated debentures | Trust II Debentures | Maximum |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notice period required for redemption of debentures |  |  |  |  | 60 days |  |
Redemption price of debentures as a percentage of principal |  |  |  |  | 100.00% |  |
Subordinated debentures | Trust II Debentures | 3 Month LIBOR |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Spread on variable rate |  |  |  |  | 3.35% |  |
Subordinated debentures | Trust III Debentures |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debenture issued |  |  |  |  | $ 2,062,000 |  |
Subordinated debentures | Trust III Debentures | Minimum |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notice period required for redemption of debentures |  |  |  |  | 30 days |  |
Subordinated debentures | Trust III Debentures | Maximum |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notice period required for redemption of debentures |  |  |  |  | 60 days |  |
Redemption price of debentures as a percentage of principal |  |  |  |  | 100.00% |  |
Subordinated debentures | Trust III Debentures | 3 Month LIBOR |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Spread on variable rate |  |  |  |  | 1.67% |  |
Subordinated debentures | DCB Trust I Debentures |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debenture issued |  |  |  |  | $ 5,155,000 |  |
Subordinated debentures | DCB Trust I Debentures | Minimum |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notice period required for redemption of debentures |  |  |  |  | 30 days |  |
Subordinated debentures | DCB Trust I Debentures | Maximum |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notice period required for redemption of debentures |  |  |  |  | 60 days |  |
Redemption price of debentures as a percentage of principal |  |  |  |  | 100.00% |  |
Subordinated debentures | DCB Trust I Debentures | 3 Month LIBOR |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Spread on variable rate |  |  |  |  | 1.80% |  |
Subordinated debentures | Other Debentures Issued in July 2015 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debenture issued |  |  |  |  |  |  | $ 4,000,000
Debentures that matured and were paid off |  | $ 1,000,000 |  |  |  |  |
Repayments of related party debt |  |  |  | $ 3,000,000 |  |  |
Subordinated debentures | Other Debentures Issued in July 2015 | Subsequent Event |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debentures that matured and were paid off | $ 1,000,000 |  |  |  |  |  |
Subordinated debentures | Other Debentures Issued in July 2015 | Directors and Related Parties |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debenture issued |  |  |  |  |  |  | $ 3,000,000
Subordinated debentures | Other Subordinated Debentures Issued in July 2015, 2.50%, Maturing July 1, 2017 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate |  |  | 2.50% |  |  |  |
Debentures that matured and were paid off |  |  | $ 500,000 |  |  |  |
Subordinated debentures | Other Subordinated Debentures Issued in July 2015, 4.00%, Maturing January 1, 2019 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate |  |  |  |  | 4.00% |  |
Debenture outstanding |  |  |  |  | $ 500,000 |  |
Subordinated debentures | Other Debentures Issued in December 2015 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notice period required for redemption of debentures |  |  |  |  | 30 days |  |
Redemption price of debentures as a percentage of principal |  |  |  |  | 100.00% |  |
Debenture issued |  |  |  |  | $ 1,000,000 | $ 5,000,000 |
Repayments of related party debt |  |  |  | $ 2,000,000 |  |  |
Debenture issued, par value per instrument issued |  |  |  |  | $ 500,000 |  |
Debt instrument maturity start date |  |  |  |  | Jan. 01, 2020 |  |
Debt instrument maturity end date |  |  |  |  | Jul. 01, 2020 |  |
Subordinated debentures | Other Debentures Issued in December 2015 | Directors and Related Parties |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debenture issued |  |  |  |  |  | $ 2,500,000 |
Subordinated debentures | Other Debentures Issued in December 2015 | Minimum |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate |  |  |  |  | 4.50% |  |
Subordinated debentures | Other Debentures Issued in December 2015 | Maximum |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Stated interest rate |  |  |  |  | 5.00% |  |

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