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Fair Value of Financial Instruments - Narrative (Details) - USD ($) | 9 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024 | Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Servicing asset at fair value, gain on disposal |  | $ 410,000 |  |
Mortgage servicing rights assets recognized or recorded during period | $ 0 |  |  |
Carrying value MSR assets | 0 | $ 0 | $ 0 | $ 15,637,000
Equity investments | 27,800,000 |  | 28,200,000 |
Other financial institutions, excluding FRBD and FHLB | 3,300,000 |  | 43,400,000 |
Impairment recorded on investments in equity securities that do not have readily determinable fair values | 0 |  |  |
Loan balance individually evaluated | 14,308,000 |  | 17,724,000 |
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Loan balance individually evaluated | 5,300,000 |  | 4,500,000 |
Foreclosed assets | 577,000 |  | 3,600,000 |
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring | Residential real estate | Residential real estate |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Residential mortgage loans in the process of foreclosure | $ 2,800,000 |  | $ 5,100,000 |
Maximum | Measurement Input, Credit Spread |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Credit spread, securities at fair value through income | 2.27% |  | 2.27% |

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