v3.26.1
Investment Securities - Amortized Cost and Fair Value, by Contractual Maturity (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Amortized Cost    
Due after one year through five years $ 82,936  
Due after five years through ten years 36,225  
Due after ten years 184,011  
Total contractual maturities 303,172  
Available-for-sale investment securities, amortized cost 2,275,837 $ 2,246,716
Fair Value    
Due after one year through five years 83,458  
Due after five years through ten years 36,246  
Due after ten years 184,182  
Total contractual maturities 303,886  
Total available-for-sale securities 2,094,699 2,076,233
Amortized Cost    
Due after five years through ten years 61,397  
Due after ten years 38,285  
Total contractual maturities 99,682  
Amortized cost 3,411,684 3,533,082
Fair Value    
Due after five years through ten years 56,930  
Due after ten years 34,317  
Total contractual maturities 91,247  
Total held-to-maturity securities 3,035,475 3,188,775
Government agency debt securities    
Amortized Cost    
Amortized cost 44,479 46,182
Fair Value    
Total held-to-maturity securities 40,850 42,947
Mortgage-backed securities:    
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 1,221,115  
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 1,112,811  
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 1,221,610  
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 1,096,409  
Residential - Government agency    
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 25,704  
Available-for-sale investment securities, amortized cost 25,704 30,948
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 25,037  
Total available-for-sale securities 25,037 30,367
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 35,787  
Amortized cost 35,787 37,081
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 31,356  
Total held-to-maturity securities 31,356 32,619
Residential - Government-sponsored enterprises    
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 925,419  
Available-for-sale investment securities, amortized cost 925,419 933,206
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 865,210  
Total available-for-sale securities 865,210 878,215
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 83,559  
Amortized cost 83,559 86,681
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 72,761  
Total held-to-maturity securities 72,761 76,020
Commercial - Government agency    
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 230,216  
Available-for-sale investment securities, amortized cost 230,216 237,192
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 183,542  
Total available-for-sale securities 183,542 191,177
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 30,162  
Amortized cost 30,162 30,796
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 22,873  
Total held-to-maturity securities 22,873 23,259
Commercial - Government-sponsored enterprises    
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 39,776  
Available-for-sale investment securities, amortized cost 39,776 42,798
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 39,022  
Total available-for-sale securities 39,022 41,599
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 1,072,102  
Amortized cost 1,072,102 1,088,838
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 969,419  
Total held-to-maturity securities 969,419 993,751
Collateralized mortgage obligations    
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 751,550  
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 678,002  
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 2,090,392  
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 1,847,819  
Government agency    
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 433,114  
Available-for-sale investment securities, amortized cost 433,114 461,160
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 394,290  
Total available-for-sale securities 394,290 426,276
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 787,083  
Amortized cost 787,083 823,423
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 692,452  
Total held-to-maturity securities 692,452 738,814
Government-sponsored enterprises    
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 318,436  
Available-for-sale investment securities, amortized cost 318,436 336,451
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 283,712  
Total available-for-sale securities 283,712 302,996
Amortized Cost    
Mortgaged-backed securities and collateralized mortgage obligations 1,303,309  
Amortized cost 1,303,309 1,365,087
Fair Value    
Mortgaged-backed securities and collateralized mortgage obligations 1,155,367  
Total held-to-maturity securities $ 1,155,367 $ 1,229,942