v3.25.2
Fair Value of Assets and Liabilities - Narrative (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2025
Dec. 31, 2024
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Fixed income securities, at fair value $ 54,435 $ 52,747
Assets at fair value 66,783 63,521
Fixed Income Securities Valued Based on Nonbinding Broker Quotes    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Assets at fair value 24 22
Municipal Not Rated by Third Party Credit Rating Agencies    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Assets at fair value 2 2
Significant unobservable inputs (Level 3)    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Assets at fair value 775 805
Recurring basis    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Fixed income securities, at fair value 54,435 52,747
Assets at fair value 66,781 63,518
Recurring basis | Significant unobservable inputs (Level 3)    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Fixed income securities, at fair value 273 248
Debt securities valued based on third-party discounted cash flow pricing models 85 87
Assets at fair value 773 $ 802
Limited partnership interests    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Commitments to invest in limited partnership interests $ 138  
Limited partnership interests | Minimum    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Investment assets, useful life (in years) 10 years  
Limited partnership interests | Maximum    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Investment assets, useful life (in years) 12 years