v3.26.1
Accumulated Other Comprehensive Income (Loss) - Changes in Each Component of Accumulated Other Comprehensive Income (Loss), Net of Tax (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance $ 552,243 $ 397,434 $ 543,474 $ 388,502
Ending balance 566,785 404,137 566,785 404,137
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance (38,643) (47,655) (35,522) (48,851)
Other comprehensive gain (loss) before reclassifications 3,436 (2,071) 315 (875)
Ending balance (35,207) (49,726) (35,207) (49,726)
Defined Benefit Pension Items [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance (4,735) (4,294) (4,735) (4,506)
Other comprehensive gain (loss) before reclassifications 0 0 0 212
Ending balance (4,735) (4,294) (4,735) (4,294)
Cashflow Hedge [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance 174   (58)  
Other comprehensive gain (loss) before reclassifications 98   330  
Ending balance 272   272  
Accumulated Other Comprehensive Income (Loss) [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Beginning balance (43,204) (51,949) (40,315) (53,357)
Other comprehensive gain (loss) before reclassifications 3,534 (2,071) 645 (663)
Ending balance $ (39,670) $ (54,020) $ (39,670) $ (54,020)