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Securities - Narrative (Details) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2024 USD ($) | Mar. 31, 2024 USD ($) | Dec. 31, 2024 USD ($) security | Dec. 31, 2023 USD ($) security | Dec. 31, 2022 USD ($)
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Private mortgage-backed security fair value |  |  | $ 700,000 | $ 700,000 |
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] |  |  | Accrued interest receivable | Accrued interest receivable |
Accrued interest on available for sale debt securities |  |  | $ 4,600,000 | $ 5,200,000 |
Debt Securities, Held-to-Maturity, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] |  |  | Accrued interest receivable | Accrued interest receivable |
Accrued interest on held to maturity debt securities |  |  | $ 4,200,000 | $ 4,200,000 |
Number of securities | security |  |  | 584 | 657 |
Number of securities in an unrealized loss position | security |  |  | 560 | 632 |
Investment securities, pledged as collateral for public deposits |  |  | $ 690,500,000 |  |
Gain on sale of VISA B shares |  |  | 4,500,000 |  |
Proceeds from sales of securities available for sale |  |  | 385,125,000 | $ 111,863,000 | $ 0
Securities losses, net |  |  | (41,500,000) |  |
Proceeds from maturities, calls and principal repayments of securities available for sale |  | $ 5,200,000 | 243,029,000 | 165,358,000 | $ 251,314,000
Securities losses, net |  | $ (1,000,000.0) |  | 0 |
FHLB stock and FRB stock, cost |  |  | 41,300,000 | 54,500,000 |
FHLB, cost |  |  | 8,500,000 | 21,700,000 |
FRB stock |  |  | 32,700,000 | 32,800,000 |
Common Class B |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Gain on sale of VISA B shares | $ 4,500,000 |  |  |  |
Carrying value of shares | $ 0 |  |  |  |
Collateral For Public Deposits |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Investment securities, pledged as collateral for public deposits |  |  | 806,000,000.0 | 971,300,000 |
Collateral For FRB Borrowings |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Investment securities, pledged as collateral for public deposits |  |  | $ 661,000,000.0 | $ 679,000,000.0 |

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