v3.26.3
Fair Value of Assets and Liabilities - Narrative (Details) - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Fixed income securities, at fair value $ 60,246 $ 59,115
Assets at fair value 75,812 72,025
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 11 12
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 5 29
Recurring basis    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Fixed income securities, at fair value 60,246 59,115
Assets at fair value 75,619 71,993
Significant unobservable inputs (Level 3)    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Assets at fair value 762 516
Significant unobservable inputs (Level 3) | Recurring basis    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Fixed income securities, at fair value 418 308
Debt securities valued based on third-party discounted cash flow pricing models 204 146
Assets at fair value 569 $ 484
Limited partnership interests    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Commitments to invest in limited partnership interests $ 115  
Minimum | Limited partnership interests    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Investment assets, useful life (in years) 10 years  
Maximum | Limited partnership interests    
Fair value of assets and liabilities measured on recurring and non-recurring basis    
Investment assets, useful life (in years) 12 years