Commitments and Contingencies - Additional Information (Detail) - USD ($) |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
|
| Other Commitments [Line Items] | ||||
| Outstanding loan commitments | $ 273,800,000 | $ 273,800,000 | $ 283,200,000 | |
| Cancellable amounts | 111,400,000 | 111,400,000 | 108,400,000 | |
| Outstanding stand-by letters of credit | 13,500,000 | 13,500,000 | 12,500,000 | |
| Provision for credit losses for unfunded commitments | 0 | 0 | ||
| Previously unearned sale proceeds | 300,000 | 42,075,000 | $ 132,141,000 | |
| Future commitments outstanding related to investments | 5,600,000 | 5,600,000 | ||
| MSR Assets [Member] | ||||
| Other Commitments [Line Items] | ||||
| Reserve | 1,400,000 | 1,400,000 | 1,800,000 | |
| Other Liabilities [Member] | ||||
| Other Commitments [Line Items] | ||||
| Reserves for unfunded commitments to borrowers | $ 900,000 | $ 900,000 | $ 900,000 | |