v3.25.4
Investments - Carrying Value and Fair Value of Securities Pledged as Collateral to Secure Public Deposits (Detail) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Debt Securities, Available-for-Sale [Line Items]    
Book Value $ 828,100 $ 897,325
Fair Value 836,537 836,868
Public Fund Deposits [Member]    
Debt Securities, Available-for-Sale [Line Items]    
Book Value 785,200 732,935
Fair Value 793,014 690,855
Federal Home Loan Bank Pledging [Member]    
Debt Securities, Available-for-Sale [Line Items]    
Book Value 0 104,888
Fair Value 0 90,406
Federal Reserve Bank Borrowings [Member]    
Debt Securities, Available-for-Sale [Line Items]    
Book Value 2,002 10,481
Fair Value 2,042 10,358
Retail Repurchase Agreements [Member]    
Debt Securities, Available-for-Sale [Line Items]    
Book Value 40,898 49,021
Fair Value $ 41,481 $ 45,249