v3.25.1
Fair Value Measurements - Senior and Subordinated Notes (Details) - USD ($)
$ in Millions
Mar. 31, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized Cost $ 1,948 $ 1,833
Fair Value 1,889  
Senior Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized Cost 993 993
Fair Value 930  
Junior Subordinated Debt    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized Cost 955 840
Fair Value $ 959  
Senior Notes Due 2029 | Senior Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Stated interest rate 4.95%  
Amortized Cost $ 497 497
Fair Value $ 498  
Senior Notes, Due 2031 | Senior Notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Stated interest rate 3.10%  
Amortized Cost $ 496 496
Fair Value $ 432  
Junior Subordinated Notes Due 2040 | Junior Subordinated Debt    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Stated interest rate 5.75%  
Amortized Cost $ 116 346
Fair Value $ 117  
Junior Subordinated Notes Due 2042 | Junior Subordinated Debt    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Stated interest rate 5.50%  
Amortized Cost $ 494 494
Fair Value $ 487  
Junior Subordinated Notes Due 2045 | Junior Subordinated Debt    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Stated interest rate 7.50%  
Amortized Cost $ 345 $ 0
Fair Value $ 355