v3.26.1
Debt and Equity Securities - Schedule of Amortized Cost and Estimated Fair Value of Securities (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Amortized Cost    
Amortized Cost $ 3,980,545 $ 3,998,939
Fair Value    
Fair Value 3,913,855 3,951,455
Fair Value    
Fair Value 638,584 $ 654,832
Available-for-sale    
Amortized Cost    
Due within one year 0  
Due after one year through five years 0  
Due after five years through ten years 257,612  
Due after ten years 3,722,933  
Amortized Cost 3,980,545  
Fair Value    
Due within one year 0  
Due after one year through five years 0  
Due after five years through ten years 259,076  
Due after ten years 3,654,779  
Fair Value 3,913,855  
Held-to-maturity    
Amortized Cost    
Due within one year 0  
Due after one year through five years 0  
Due after five years through ten years 0  
Due after ten years 709,594  
Amortized Cost 709,594  
Fair Value    
Due within one year 0  
Due after one year through five years 0  
Due after five years through ten years 0  
Due after ten years 638,584  
Fair Value $ 638,584