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v3.25.1

Borrowings - Additional information (Details) $ in Millions |  | 3 Months Ended |  |
--- | --- | --- | --- | ---
Feb. 24, 2020 USD ($) | Mar. 31, 2025 USD ($) item | Jun. 30, 2021 USD ($) | Dec. 31, 2024 USD ($) | Dec. 06, 2024 item
Borrowings |  |  |  |  |
Number of customers having secured balances exceeding specified percentage of stockholders equity | item |  | 0 |  |  |
Threshold percentage of stockholders' equity |  | 10.00% |  |  |
Borrowings at FHLBC as percentage of total assets |  | 35.00% |  |  |
Number of bank branches acquired | item |  |  |  |  | 5
FHLBC stock |  | $ 4.5 |  | $ 4.5 |
Proceeds from term note | $ 30.0 |  |  |  |
Outstanding, net of deferred issuance costs |  | 59.5 |  | 59.5 |
Asset Pledged as Collateral with Right | Securities sold under repurchase agreements |  |  |  |  |
Borrowings |  |  |  |  |
Investment securities pledged with financial institutions, dollars |  | 73.9 |  | 73.6 |
Securities sold under repurchase agreements |  |  |  |  |
Borrowings |  |  |  |  |
Investment securities pledged with financial institutions, dollars |  | $ 38.7 |  | 36.7 |
Federal Home Loan Bank Advances |  |  |  |  |
Borrowings |  |  |  |  |
Borrowings at FHLBC as percentage of book value of certain mortgage loans |  | 60.00% |  |  |
FHLBC advance amount |  |  |  | $ 20.0 |
FHLBC stock |  | $ 4.5 |  |  |
Principal balance of loans collateralized |  | 1,400.0 |  |  |
Combined collateral value |  | 929.8 |  |  |
Amount available for additional borrowings |  | $ 928.6 |  |  |
Subordinated Notes Due 2031 |  |  |  |  |
Borrowings |  |  |  |  |
Interest rate (as a percent) |  |  | 3.50% |  |
Face amount |  |  | $ 60.0 |  |
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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