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Borrowings - Additional information (Details) $ in Thousands |  | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Feb. 24, 2023 USD ($) | Dec. 31, 2016 | Jun. 30, 2023 USD ($) | Jun. 30, 2021 USD ($) | Dec. 31, 2024 USD ($) customer | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($)
Borrowings |  |  |  |  |  |  |
Threshold percentage of stockholders' equity |  |  |  |  | 10.00% |  |
Borrowings at FHLBC as percentage of total assets |  |  |  |  | 35.00% |  |
FHLBC stock |  |  |  |  | $ 4,500 | $ 18,500 |
Proceeds from term note |  |  |  |  | 30,000 |  |
Repayment of term note |  |  |  |  |  | 9,000 | $ 4,000
Outstanding, net of deferred issuance costs |  |  |  |  | 59,500 | 59,400 |
Asset Pledged as Collateral with Right | Securities sold under repurchase agreements |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Investment securities pledged with financial institutions, dollars |  |  |  |  | 73,600 | 45,700 |
Securities sold under repurchase agreements |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Investment securities pledged with financial institutions, dollars |  |  |  |  | $ 36,700 | 26,500 |
Number of customers having secured balances exceeding specified percentage of stockholders equity | customer |  |  |  |  | 0 |  |
Securities sold under repurchase agreements | Minimum |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Maturity |  |  |  |  | 1 day |  |
Securities sold under repurchase agreements | Maximum |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Maturity |  |  |  |  | 90 days |  |
Federal Home Loan Bank Advances |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Borrowings at FHLBC as percentage of book value of certain mortgage loans |  |  |  |  | 60.00% |  |
FHLBC advance amount |  |  |  |  | $ 20,000 | 405,000 |
FHLBC stock |  |  |  |  | 4,500 | 18,500 |
Principal balance of loans collateralized |  |  |  |  | 1,410,000 | $ 1,460,000 |
Maximum borrowing capacity |  |  |  |  | 942,800,000 |  |
Combined collateral value |  |  |  |  | 942,800 |  |
Amount available for additional borrowings |  |  |  |  | $ 922,800 |  |
Senior notes |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Interest rate (as a percent) |  | 5.75% |  |  |  |  |
Debt Instrument, Term |  | 10 years |  |  |  |  |
Interest rate term |  | 5 years |  |  |  |  |
Debt issuance costs |  |  | $ 362 |  |  |  |
Debt instrument redemption price, percentage |  |  | 12.85% |  |  |  |
Debt redeemed amount |  |  | $ 45,000 |  |  |  |
Term Debt |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Repayment of term note | $ 9,000 |  |  |  |  |  |
Face amount | $ 20,000 |  |  |  |  |  |
Subordinated Notes Due 2031 |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  | 3.50% |  |  |
Face amount |  |  |  | $ 60,000 |  |  |
Subordinated Notes Due 2031 | Three Months Secured Overnight Financing Rate |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |
Basis points added to reference rate (as a percent) |  |  |  | 2.73% |  |  |

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