v3.25.2
Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale $ 43,357 $ 41,827
Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 25,688 24,944
States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 7,375 6,804
Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 8,719 8,416
Fair Value, Recurring    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 42,733 41,061
Fixed maturities trading 624 766
Total fixed maturities 43,357 41,827
Equity securities 1,294 1,064
Short-term and other 4,292 4,453
Receivables 1 5
Payable to brokers (41) (88)
Fair Value, Recurring | Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 26,639 25,841
Fair Value, Recurring | States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 7,375 6,804
Fair Value, Recurring | Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 8,719 8,416
Fair Value, Recurring | Level 1    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 229 223
Fixed maturities trading 559 766
Total fixed maturities 788 989
Equity securities 815 603
Short-term and other 4,247 4,383
Receivables
Payable to brokers (41) (88)
Fair Value, Recurring | Level 1 | Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 229 223
Fair Value, Recurring | Level 1 | States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale
Fair Value, Recurring | Level 1 | Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale
Fair Value, Recurring | Level 2    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 40,186 38,642
Fixed maturities trading 65
Total fixed maturities 40,251 38,642
Equity securities 469 441
Short-term and other 45 70
Receivables 1 5
Payable to brokers
Fair Value, Recurring | Level 2 | Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 25,022 24,340
Fair Value, Recurring | Level 2 | States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 7,331 6,762
Fair Value, Recurring | Level 2 | Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 7,833 7,540
Fair Value, Recurring | Level 3    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 2,318 2,196
Fixed maturities trading
Total fixed maturities 2,318 2,196
Equity securities 10 20
Short-term and other
Receivables
Payable to brokers
Fair Value, Recurring | Level 3 | Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 1,388 1,278
Fair Value, Recurring | Level 3 | States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 44 42
Fair Value, Recurring | Level 3 | Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale $ 886 $ 876