Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Other Commitments [Line Items] | ||
| Outstanding loan commitments | $ 253.6 | $ 247.2 |
| Cancellable amounts | 35.6 | 35.2 |
| Outstanding stand-by letters of credit | 6.1 | 6.3 |
| Future commitments outstanding related to investments | 4.7 | 4.9 |
| Other Liabilities [Member] | ||
| Other Commitments [Line Items] | ||
| Reserves for unfunded commitments to borrowers | $ 0.8 | $ 0.8 |