Securities - Schedule of ACL on HTM Securities (Detail) - USD ($) $ in Thousands |
9 Months Ended | |
|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items] | ||
| Beginning balance | $ 168 | |
| Ending balance | 169 | |
| ASU 2016-13 [Member] | ||
| Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items] | ||
| Beginning balance | 168 | $ 146 |
| Current period provision | 1 | 35 |
| Ending balance | 169 | 181 |
| 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 | 1 | 34 |
| Ending balance | 156 | 158 |
| ASU 2016-13 [Member] | Corporate Debt Securities [Member] | ||
| Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items] | ||
| Beginning balance | 13 | 22 |
| Current period provision | 0 | 1 |
| Ending balance | $ 13 | $ 23 |