v3.26.1
Investment Securities - Summary of Gross Unrealized Losses on Debt Securities (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Debt Securities Available for Sale    
Less than 12 months, fair value $ 237,034 $ 148,121
Less than 12 months, unrealized loss (3,535) (406)
12 months or more, fair value 1,230,039 1,322,068
12 months or more, unrealized loss (158,718) (153,128)
Total, fair value 1,467,073 1,470,189
Total, unrealized loss (162,253) (153,534)
Debt Securities Held to Maturity    
Less than 12 months, fair value 1,545 0
Less than 12 months, unrealized loss (19) 0
12 months or more, fair value 75,090 86,828
12 months or more, unrealized loss (4,056) (3,562)
Total, fair value 76,635 86,828
Total, unrealized loss (4,075) (3,562)
Obligations of U.S. government agencies    
Debt Securities Available for Sale    
Less than 12 months, fair value 182,391 39,263
Less than 12 months, unrealized loss (3,129) (133)
12 months or more, fair value 857,482 916,500
12 months or more, unrealized loss (117,067) (112,252)
Total, fair value 1,039,873 955,763
Total, unrealized loss (120,196) (112,385)
Debt Securities Held to Maturity    
Less than 12 months, fair value 0 0
Less than 12 months, unrealized loss 0 0
12 months or more, fair value 75,090 85,273
12 months or more, unrealized loss (4,056) (3,552)
Total, fair value 75,090 85,273
Total, unrealized loss (4,056) (3,552)
Obligations of states and political subdivisions    
Debt Securities Available for Sale    
Less than 12 months, fair value 21,882 2,874
Less than 12 months, unrealized loss (301) (106)
12 months or more, fair value 185,569 201,382
12 months or more, unrealized loss (20,145) (19,517)
Total, fair value 207,451 204,256
Total, unrealized loss (20,446) (19,623)
Debt Securities Held to Maturity    
Less than 12 months, fair value 1,545 0
Less than 12 months, unrealized loss (19) 0
12 months or more, fair value 0 1,555
12 months or more, unrealized loss 0 (10)
Total, fair value 1,545 1,555
Total, unrealized loss (19) (10)
Corporate bonds    
Debt Securities Available for Sale    
Less than 12 months, fair value 988 495
Less than 12 months, unrealized loss (10) (5)
12 months or more, fair value 0 2,229
12 months or more, unrealized loss 0 (21)
Total, fair value 988 2,724
Total, unrealized loss (10) (26)
Asset backed securities    
Debt Securities Available for Sale    
Less than 12 months, fair value 21,407 94,965
Less than 12 months, unrealized loss (44) (161)
12 months or more, fair value 64,336 70,084
12 months or more, unrealized loss (904) (1,267)
Total, fair value 85,743 165,049
Total, unrealized loss (948) (1,428)
Non-agency collateralized mortgage obligations    
Debt Securities Available for Sale    
Less than 12 months, fair value 10,366 10,524
Less than 12 months, unrealized loss (51) (1)
12 months or more, fair value 122,652 131,873
12 months or more, unrealized loss (20,602) (20,071)
Total, fair value 133,018 142,397
Total, unrealized loss $ (20,653) $ (20,072)