v3.26.1
Held-to-Maturity 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    
Carrying Value $ 11,962,094 $ 10,490,243
Estimated Fair Value    
Estimated Fair Value 11,825,765 10,384,380
Net unamortized discounts 21,000 22,100
State and local housing finance agency obligations    
Amortized Cost    
Due after one year through five years 25,100 100
Due after five years through ten years 24,805 25,920
Due after ten years 122,810 125,660
Carrying Value 172,715 151,680
Estimated Fair Value    
Due after one year through five years 25,098 100
Due after five years through ten years 24,306 25,648
Due after ten years 119,280 121,037
Estimated Fair Value 168,684 146,785
Total MBS    
Amortized Cost    
Due in one year or less 893,356 914,538
Due after one year through five years 4,242,261 4,565,613
Due after five years through ten years 1,768,974 1,766,708
Due after ten years 4,884,788 3,091,704
Carrying Value 11,789,379 10,338,563
Estimated Fair Value    
Due in one year or less 887,148 907,705
Due after one year through five years 4,136,991 4,490,399
Due after five years through ten years 1,752,787 1,749,324
Due after ten years 4,880,155 3,090,167
Estimated Fair Value $ 11,657,081 $ 10,237,595