Securities - Schedule of Allowance for Credit Losses on Held-to-maturity Securities (Detail) - USD ($) $ in Thousands |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items] | ||
| Beginning balance | $ 168 | |
| Ending balance | 165 | |
| ASU 2016-13 [Member] | ||
| Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items] | ||
| Beginning balance | 168 | $ 146 |
| Current period provision | (3) | 32 |
| Ending balance | 165 | 178 |
| ASU 2016-13 [Member] | Obligations of State and Political Subdivisions [Member] | ||
| Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items] | ||
| Beginning balance | 155 | 124 |
| Current period provision | 0 | 17 |
| Ending balance | 155 | 141 |
| ASU 2016-13 [Member] | Corporate Debt Securities [Member] | ||
| Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items] | ||
| Beginning balance | 13 | 22 |
| Current period provision | (3) | 15 |
| Ending balance | $ 10 | $ 37 |