v3.25.4
Investments (Amortized Cost and Fair Value of Available-for-Sale Debt Securities by Contractual Maturity) (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Schedule of Investments [Line Items]    
Due in one year or less, Amortized Cost $ 3,859  
Due after one year through five years, Amortized Cost 13,775  
Due after five years through ten years, Amortized Cost 11,962  
Due after ten years, Amortized Cost 6,950  
Total debt securities - available-for-sale, Amortized Cost 49,578 $ 49,815
Due in one year or less, Fair Value 3,843  
Due after one year through five years, Fair Value 13,547  
Due after five years through ten years, Fair Value 11,670  
Due after ten years, Fair Value 6,743  
Debt Securities, Available-for-sale 48,182 46,919
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost 266  
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value 266  
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost 202  
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value 203  
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost 5  
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value 5  
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Amortized Cost 17  
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value 15  
Debt Securities, Held-to-maturity 490 512
Debt Securities, Held-to-maturity, Fair Value 489 508
U.S. Agency Mortgage-Backed Securities [Member]    
Schedule of Investments [Line Items]    
Mortgage-backed securities, Amortized Cost 10,284  
Total debt securities - available-for-sale, Amortized Cost 10,284 10,577
Debt Securities, Available-for-sale 9,719 9,584
Mortgage-backed securities, Fair Value 9,719  
Non-U.S. Agency Mortgage-Backed Securities [Member]    
Schedule of Investments [Line Items]    
Mortgage-backed securities, Amortized Cost 2,748  
Total debt securities - available-for-sale, Amortized Cost 2,748 2,890
Debt Securities, Available-for-sale 2,660 $ 2,717
Mortgage-backed securities, Fair Value $ 2,660