v3.26.1
Investments - Amortized Cost and Fair Value of Securities Available-for-Sale (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Schedule Of Available For Sale Securities [Line Items]    
Available-for-Sale, Amortized Cost $ 1,235,954 $ 1,022,470
Available-for-Sale, Gross Unrealized Gains 3,851 10,986
Available-for-Sale, Gross Unrealized Losses (10,113) (2,888)
Available-for-Sale, Fair Value 1,229,692 1,030,568
U.S. Government Sponsored Entities [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Available-for-Sale, Amortized Cost 25,891 25,960
Available-for-Sale, Gross Unrealized Gains 84 338
Available-for-Sale, Fair Value 25,975 26,298
U.S. Treasury securities [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Available-for-Sale, Amortized Cost 40,027 35,134
Available-for-Sale, Gross Unrealized Gains 32 116
Available-for-Sale, Gross Unrealized Losses (18)  
Available-for-Sale, Fair Value 40,041 35,250
Government-Sponsored Residential Mortgage-Backed Securities [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Available-for-Sale, Amortized Cost 965,399 763,827
Available-for-Sale, Gross Unrealized Gains 2,944 9,598
Available-for-Sale, Gross Unrealized Losses (8,114) (1,280)
Available-for-Sale, Fair Value 960,229 772,145
Private Label Residential Mortgage-Backed Securities [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Available-for-Sale, Amortized Cost 4,110 4,441
Available-for-Sale, Gross Unrealized Losses (72) (115)
Available-for-Sale, Fair Value 4,038 4,326
Corporate [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Available-for-Sale, Amortized Cost 94,709 92,142
Available-for-Sale, Gross Unrealized Gains 680 734
Available-for-Sale, Gross Unrealized Losses (1,183) (1,078)
Available-for-Sale, Fair Value 94,206 91,798
Small Business Administration Loan Pools [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Available-for-Sale, Amortized Cost 83,591 80,199
Available-for-Sale, Gross Unrealized Gains 67 130
Available-for-Sale, Gross Unrealized Losses (416) (124)
Available-for-Sale, Fair Value 83,242 80,205
State and Political Subdivisions [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Available-for-Sale, Amortized Cost 22,227 20,767
Available-for-Sale, Gross Unrealized Gains 44 70
Available-for-Sale, Gross Unrealized Losses (310) (291)
Available-for-Sale, Fair Value $ 21,961 $ 20,546