v3.26.1
Available-for-Sale Securities - Schedule of Amortized Cost and Estimated Fair Value of Investments by Contractual Maturity (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Amortized Cost    
Amortized Cost $ 12,763,624 $ 12,377,325
Estimated Fair Value    
Estimated Fair Value 12,720,131 12,345,845
Net unamortized (premium) / discounts 59,100 44,700
Housing and U.S. obligations    
Amortized Cost    
Due in one year or less 251,436 0
Due after one year through five years 205,910 458,799
Due after five years through ten years 98,972 98,886
Due after ten years 1,664,730 1,665,775
Amortized Cost 2,221,048 2,223,460
Estimated Fair Value    
Due in one year or less 250,864 0
Due after one year through five years 203,289 461,229
Due after five year through ten years 97,215 99,043
Due after ten years 1,666,174 1,664,523
Estimated Fair Value 2,217,542 2,224,795
Mortgage-backed securities    
Amortized Cost    
Due in one year or less 574,871 492,677
Due after one year through five years 2,617,079 2,348,575
Due after five years through ten years 6,511,883 6,464,250
Due after ten years 838,743 848,363
Amortized Cost 10,542,576 10,153,865
Estimated Fair Value    
Due in one year or less 571,581 488,360
Due after one year through five years 2,592,712 2,338,486
Due after five year through ten years 6,508,698 6,456,546
Due after ten years 829,598 837,658
Estimated Fair Value $ 10,502,589 $ 10,121,050