Investment Securities and Other Investments - Additional Information (Detail) - USD ($) |
Mar. 31, 2026 |
Dec. 31, 2025 |
|||
|---|---|---|---|---|---|
| Schedule Of Investments [Line Items] | |||||
| Investment securities classified as held to maturity | $ 0 | $ 0 | |||
| Unrealized gain position | 28,700,000 | 42,400,000 | |||
| Federal home loan bank stock | 8,900,000 | 9,100,000 | |||
| Federal reserve bank stock | 9,000,000 | 9,400,000 | |||
| Correspondent bank stock | 500,000 | 500,000 | |||
| Other equity investments | 5,000,000 | 4,900,000 | |||
| Other Investments, Total | 20,916,000 | 20,781,000 | [1] | ||
| Asset Pledged as Collateral without Right [Member] | FHLB [Member] | |||||
| Schedule Of Investments [Line Items] | |||||
| Securities pledged | 169,800,000 | 174,300,000 | |||
| Third Party Investment Grade [Member] | |||||
| Schedule Of Investments [Line Items] | |||||
| Securities pledged | $ 22,700,000 | $ 23,500,000 | |||
| |||||
| X | ||||||||||
- Definition Correspondent bank stock. No definition available.
|
| X | ||||||||||
- Definition Debt securities available for sale unrealized gain position No definition available.
|
| X | ||||||||||
- Definition Amount, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity), and investment in debt security measured at fair value with change in fair value recognized in net income (trading). Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Fair value portion of investments accounted under the equity method. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Federal Reserve Bank stock represents an equity interest in the Federal Reserve Bank. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of investments classified as other. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|