v3.25.2
Fair Value of Financial Instruments - Changes in the Level 3 Fair Value Category of Unobservable Inputs (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
State and Local Governments Tax-Exempt [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Beginning Balance $ 184 $ 521 $ 353 $ 1,188
Change in Fair Value   (1) 1 (3)
Payments, Maturities & Calls     (170) (665)
Ending Balance 184 520 184 520
State and Local Governments Taxable[Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Beginning Balance 1,276 1,274 1,274 1,272
Change in Fair Value (6) (8) (4) (6)
Ending Balance 1,270 1,266 1,270 1,266
State and Local Governments [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Beginning Balance 1,460 1,795 1,627 2,460
Change in Fair Value (6) (9) (3) (9)
Payments, Maturities & Calls     (170) (665)
Ending Balance $ 1,454 $ 1,786 $ 1,454 $ 1,786