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Subordinated Debentures - Additional Information (Details) - USD ($) |  |  | 9 Months Ended |
--- | --- | --- | --- | ---
Feb. 19, 2016 | Mar. 15, 2012 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016
Debt Instrument [Line Items] |  |  |  |  |
Debt instrument, face amount |  |  | $ 50,000,000 |  | $ 50,000,000
Subordinated Debentures |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Percentage of principal amount redeemed |  | 100.00% |  |  |
Debt instrument redemption period |  |  | Mar. 15, 2012 |  |
Debt instrument maturity period |  |  | Mar. 15, 2037 |  |
Defer interest payments maximum period |  |  | 5 years |  |
Debt instrument interest rate description |  |  | three month London Interbank Offered Rate (LIBOR) plus 1.65%, which was 2.97% and 2.61% at September 30, 2017 and December 31, 2016 |  |
Debt instrument interest percentage |  |  | 2.97% |  | 2.61%
TFC Statutory Trust | Private Offering |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Number of trust preferred securities | 5,000 |  |  |  |
Trust preferred securities liquidation amount per preferred security | $ 1,000 |  |  |  |
TFC Statutory Trust | Subordinated Debentures |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt instrument, face amount | $ 5,000,000 |  |  |  |
Debt valuation reserve | 1,900,000 |  |  |  |
Debt amortization expense |  |  | $ 68,000 | $ 55,000 |
TFC Statutory Trust | Fair Value, Inputs, Level 1 |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Subordinated debenture liability | $ 3,255,000 |  |  |  |
Other Assets |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Investment in common stock |  |  | $ 155,000 |  |
London Interbank Offered Rate | Subordinated Debentures |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt instrument, basis points |  |  | 1.65% |  |

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