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Subordinated Debentures (Details) - USD ($) | 1 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Dec. 22, 2005 | Jun. 26, 2003 | Sep. 30, 2019 | Dec. 31, 2020 | Dec. 31, 2019
Subordinated Debentures (Textual) |  |  |  |  |
Subordinated debentures |  |  |  | $ 35,998,000 | $ 35,890,000
Dodd-Frank Act prohibits, Description |  |  |  | Dodd-Frank Act prohibit institutions that had more than $15 billion in assets on December 31, 2009 from including trust preferred securities as Tier 1 capital beginning in 2013, with one-third phased out over the two years ending in 2015. Financial institutions with less than $15 billion in total assets, such as the Bank, may continue to include their trust preferred securities issued prior to May 19, 2010 in Tier 1 capital, but cannot include in Tier 1 capital trust preferred securities issued after such date. |
Subordinated Debt [Member] |  |  |  |  |
Subordinated Debentures (Textual) |  |  |  |  |
Aggregate principal amount of subordinated notes |  |  | $ 23,000,000.0 |  |
Rate of interest of subordinated notes |  |  | 4.75% |  |
Proceeds from issue of subordinated debts |  |  | $ 22,500,000 |  |
Term of subordinated notes |  |  | 10 years |  |
Basis points of interest rate calculation |  |  | 340.80% |  |
Greenville First Statutory Trust One [Member] |  |  |  |  |
Subordinated Debentures (Textual) |  |  |  |  |
Amount of trust preferred securities issued at floating rate |  | $ 6,000,000.0 |  |  |
Maturity date of trust preferred securities |  | Jun. 26, 2033 |  |  |
Floating interest rate of trust preferred securities |  |  |  | 3.35% |
LIBOR rate |  |  |  | 3.10% |
Indexed period of LIBOR rate |  |  |  | 3-month |
Proceeds from issuance trust preferred securities |  |  |  | $ 6,000,000.0 |
Initial proceeds from capital investment in trust |  |  |  | 186,000 |
Subordinated debentures |  |  |  | $ 6,200,000 |
Greenville First Statutory Trust Two [Member] |  |  |  |  |
Subordinated Debentures (Textual) |  |  |  |  |
Amount of trust preferred securities issued at floating rate | $ 7,000,000.0 |  |  |  |
Maturity date of trust preferred securities | Dec. 22, 2035 |  |  |  |
Floating interest rate of trust preferred securities |  |  |  | 1.68% |
LIBOR rate |  |  |  | 1.44% |
Indexed period of LIBOR rate |  |  |  | 3-month |
Proceeds from issuance trust preferred securities |  |  |  | $ 7,000,000.0 |
Initial proceeds from capital investment in trust |  |  |  | 217,000 |
Subordinated debentures |  |  |  | $ 7,200,000 |

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