v3.26.1
Investment Securities - Amortized Cost and Estimated Fair Value of Securities Contractual Maturity (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Amortized Cost    
Due in one year or less, Amortized Cost $ 80,028  
Due in one year or less, Amortized Cost 4,967  
Due after one year through five years, Amortized Cost 235,425  
Due after one year through five years, Amortized Cost 136,319  
Due after five years through ten years, Amortized Cost 369,000  
Due after five years through ten years, Amortized Cost 375,405  
Due after ten years, Amortized Cost 735,650  
Due after ten years, Amortized Cost 629,147  
Amortized Cost 2,997,415 $ 3,088,820
Amortized Cost 1,256,807 1,261,267
Estimated Fair Value    
Due in one year or less, Estimated Fair Value 79,593  
Due in one year or less, Estimated Fair Value 4,933  
Due after one year through five years, Estimated Fair Value 224,652  
Due after one year through five years, Estimated Fair Value 130,725  
Due after five years through ten years, Estimated Fair Value 353,070  
Due after five years through ten years, Estimated Fair Value 344,164  
Due after ten years, Estimated Fair Value 694,321  
Due after ten years, Estimated Fair Value 562,751  
Total, Estimated Fair Value 2,776,216 2,871,931
Estimated Fair Value 1,148,827 1,161,052
U.S. government-sponsored mortgage-backed securities    
Amortized Cost    
Securities not due at a single maturity date, Amortized Cost 1,302,974  
Securities not due at a single maturity date, Amortized Cost 110,969  
Amortized Cost 1,302,974 1,345,469
Amortized Cost 110,969 114,813
Estimated Fair Value    
Securities not due at a single maturity date, Estimated Fair Value 1,159,938  
Securities not due at a single maturity date, Estimated Fair Value 106,254  
Total, Estimated Fair Value 1,159,938 1,212,948
Estimated Fair Value 106,254 111,955
Private mortgage-backed securities    
Amortized Cost    
Securities not due at a single maturity date, Amortized Cost 176,380  
Securities not due at a single maturity date, Amortized Cost 0  
Amortized Cost 176,380 152,578
Estimated Fair Value    
Securities not due at a single maturity date, Estimated Fair Value 167,761  
Securities not due at a single maturity date, Estimated Fair Value 0  
Total, Estimated Fair Value 167,761 145,720
Non-government-sponsored asset backed securities    
Amortized Cost    
Securities not due at a single maturity date, Amortized Cost 97,958  
Securities not due at a single maturity date, Amortized Cost 0  
Amortized Cost 97,958 158,446
Estimated Fair Value    
Securities not due at a single maturity date, Estimated Fair Value 96,881  
Securities not due at a single maturity date, Estimated Fair Value 0  
Total, Estimated Fair Value $ 96,881 $ 157,844