v3.25.2
Investment Securities and Other Investments - Additional Information (Detail) - USD ($)
Jun. 30, 2025
Dec. 31, 2024
Schedule Of Investments [Line Items]    
Unrealized gain position $ 18,100,000 $ 1,100,000
Federal home loan bank stock 9,100,000 9,400,000
Federal reserve bank stock 9,300,000 9,400,000
Correspondent bank stock 500,000 500,000
Other equity investments 4,600,000 4,800,000
Securities available for sale, at fair value 327,958,000 312,035,000 [1]
Other Investments, Total 20,938,000 19,405,000 [1]
Federal Reserve Board Bank Term Funding Program [Member]    
Schedule Of Investments [Line Items]    
Advance from federal reserve bank 0 0
Asset Pledged as Collateral without Right [Member] | FHLB [Member]    
Schedule Of Investments [Line Items]    
Securities pledged 177,000,000 268,900,000
Asset Pledged as Collateral without Right [Member] | FRB [Member]    
Schedule Of Investments [Line Items]    
Securities pledged 0 16,300,000
Third Party Investment Grade [Member]    
Schedule Of Investments [Line Items]    
Securities pledged $ 27,300,000 $ 29,300,000
[1] Derived from audited December 31, 2024 Consolidated Financial Statements.