v3.26.1
Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Fixed maturity securities:    
Fixed maturity securities $ 43,230 $ 43,402
Equity securities:    
Equity securities 785 769
Short-term and other 1,261 2,137
Total assets 45,276 46,308
Total liabilities 0 0
Corporate and other bonds    
Fixed maturity securities:    
Fixed maturity securities 26,000 26,250
States, municipalities and political subdivisions    
Fixed maturity securities:    
Fixed maturity securities 8,572 8,431
Asset-backed    
Fixed maturity securities:    
Fixed maturity securities 8,658 8,721
Common Stock    
Equity securities:    
Equity securities 247 237
Non-redeemable preferred stock    
Equity securities:    
Equity securities 538 532
Level 1    
Fixed maturity securities:    
Fixed maturity securities 246 238
Equity securities:    
Equity securities 269 259
Short-term and other 1,230 2,086
Total assets 1,745 2,583
Total liabilities 0 0
Level 1 | Corporate and other bonds    
Fixed maturity securities:    
Fixed maturity securities 246 238
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 235 224
Level 1 | Non-redeemable preferred stock    
Equity securities:    
Equity securities 34 35
Level 2    
Fixed maturity securities:    
Fixed maturity securities 40,471 40,638
Equity securities:    
Equity securities 504 497
Short-term and other 31 51
Total assets 41,006 41,186
Total liabilities 0 0
Level 2 | Corporate and other bonds    
Fixed maturity securities:    
Fixed maturity securities 24,240 24,529
Level 2 | States, municipalities and political subdivisions    
Fixed maturity securities:    
Fixed maturity securities 8,528 8,386
Level 2 | Asset-backed    
Fixed maturity securities:    
Fixed maturity securities 7,703 7,723
Level 2 | Common Stock    
Equity securities:    
Equity securities 0 0
Level 2 | Non-redeemable preferred stock    
Equity securities:    
Equity securities 504 497
Level 3    
Fixed maturity securities:    
Fixed maturity securities 2,513 2,526
Equity securities:    
Equity securities 12 13
Short-term and other 0 0
Total assets 2,525 2,539
Total liabilities 0 0
Level 3 | Corporate and other bonds    
Fixed maturity securities:    
Fixed maturity securities 1,514 1,483
Level 3 | States, municipalities and political subdivisions    
Fixed maturity securities:    
Fixed maturity securities 44 45
Level 3 | Asset-backed    
Fixed maturity securities:    
Fixed maturity securities 955 998
Level 3 | Common Stock    
Equity securities:    
Equity securities 12 13
Level 3 | Non-redeemable preferred stock    
Equity securities:    
Equity securities $ 0 $ 0