v3.25.1
Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)
$ in Millions
Mar. 31, 2025
Dec. 31, 2024
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale $ 42,723 $ 41,827
Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 25,726 24,944
States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 6,644 6,804
Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 8,663 8,416
Fair Value, Recurring    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 41,921 41,061
Fixed maturities trading 802 766
Total fixed maturities 42,723 41,827
Equity securities 1,189 1,064
Short-term and other 4,193 4,453
Receivables 3 5
Payable to brokers (61) (88)
Fair Value, Recurring | Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 26,614 25,841
Fair Value, Recurring | States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 6,644 6,804
Fair Value, Recurring | Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 8,663 8,416
Level 1 | Fair Value, Recurring    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 222 223
Fixed maturities trading 800 766
Total fixed maturities 1,022 989
Equity securities 694 603
Short-term and other 4,150 4,383
Receivables
Payable to brokers (61) (88)
Level 1 | Fair Value, Recurring | Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 222 223
Level 1 | Fair Value, Recurring | States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale
Level 1 | Fair Value, Recurring | Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale
Level 2 | Fair Value, Recurring    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 39,415 38,642
Fixed maturities trading 2
Total fixed maturities 39,417 38,642
Equity securities 478 441
Short-term and other 43 70
Receivables 3 5
Payable to brokers
Level 2 | Fair Value, Recurring | Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 25,041 24,340
Level 2 | Fair Value, Recurring | States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 6,600 6,762
Level 2 | Fair Value, Recurring | Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 7,774 7,540
Level 3 | Fair Value, Recurring    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 2,284 2,196
Fixed maturities trading
Total fixed maturities 2,284 2,196
Equity securities 17 20
Short-term and other
Receivables
Payable to brokers
Level 3 | Fair Value, Recurring | Corporate bonds and other    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 1,351 1,278
Level 3 | Fair Value, Recurring | States, municipalities and political subdivisions    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale 44 42
Level 3 | Fair Value, Recurring | Asset-backed    
Assets and Liabilities Measured at Fair Value [Abstract]    
Fixed maturities available-for-sale $ 889 $ 876