v3.25.1
Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) - USD ($)
$ in Millions
Mar. 31, 2025
Dec. 31, 2024
Fixed maturity securities:    
Fixed maturity securities $ 41,973 $ 41,111
Equity securities:    
Equity securities 695 659
Short-term and other 1,411 1,922
Total assets 44,079 43,692
Total liabilities 0 0
Corporate and other bonds    
Fixed maturity securities:    
Fixed maturity securities 26,616 25,841
States, municipalities and political subdivisions    
Fixed maturity securities:    
Fixed maturity securities 6,644 6,804
Asset-backed    
Fixed maturity securities:    
Fixed maturity securities 8,713 8,466
Common Stock    
Equity securities:    
Equity securities 182 180
Non-redeemable preferred stock    
Equity securities:    
Equity securities 513 479
Level 1    
Fixed maturity securities:    
Fixed maturity securities 222 223
Equity securities:    
Equity securities 200 198
Short-term and other 1,368 1,852
Total assets 1,790 2,273
Total liabilities 0 0
Level 1 | Corporate and other bonds    
Fixed maturity securities:    
Fixed maturity securities 222 223
Level 1 | States, municipalities and political subdivisions    
Fixed maturity securities:    
Fixed maturity securities 0 0
Level 1 | Asset-backed    
Fixed maturity securities:    
Fixed maturity securities 0 0
Level 1 | Common Stock    
Equity securities:    
Equity securities 165 162
Level 1 | Non-redeemable preferred stock    
Equity securities:    
Equity securities 35 36
Level 2    
Fixed maturity securities:    
Fixed maturity securities 39,467 38,692
Equity securities:    
Equity securities 478 441
Short-term and other 43 70
Total assets 39,988 39,203
Total liabilities 0 0
Level 2 | Corporate and other bonds    
Fixed maturity securities:    
Fixed maturity securities 25,043 24,340
Level 2 | States, municipalities and political subdivisions    
Fixed maturity securities:    
Fixed maturity securities 6,600 6,762
Level 2 | Asset-backed    
Fixed maturity securities:    
Fixed maturity securities 7,824 7,590
Level 2 | Common Stock    
Equity securities:    
Equity securities 0 0
Level 2 | Non-redeemable preferred stock    
Equity securities:    
Equity securities 478 441
Level 3    
Fixed maturity securities:    
Fixed maturity securities 2,284 2,196
Equity securities:    
Equity securities 17 20
Short-term and other 0 0
Total assets 2,301 2,216
Total liabilities 0 0
Level 3 | Corporate and other bonds    
Fixed maturity securities:    
Fixed maturity securities 1,351 1,278
Level 3 | States, municipalities and political subdivisions    
Fixed maturity securities:    
Fixed maturity securities 44 42
Level 3 | Asset-backed    
Fixed maturity securities:    
Fixed maturity securities 889 876
Level 3 | Common Stock    
Equity securities:    
Equity securities 17 18
Level 3 | Non-redeemable preferred stock    
Equity securities:    
Equity securities $ 0 $ 2