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Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Fixed maturity securities: |  |
Fixed maturity securities | $ 41,111 | $ 40,425
Equity securities: |  |
Equity securities | 659 | 683
Short-term and other | 1,922 | 2,008
Total assets | 43,692 | 43,116
Other liabilities | 0 | 1
Total liabilities | 0 | 1
Corporate and other bonds |  |
Fixed maturity securities: |  |
Fixed maturity securities | 25,841 | 25,132
States, municipalities and political subdivisions |  |
Fixed maturity securities: |  |
Fixed maturity securities | 6,804 | 7,392
Asset-backed |  |
Fixed maturity securities: |  |
Fixed maturity securities | 8,466 | 7,901
Common Stock |  |
Equity securities: |  |
Equity securities | 180 | 191
Non-redeemable preferred stock |  |
Equity securities: |  |
Equity securities | 479 | 492
Level 1 |  |
Fixed maturity securities: |  |
Fixed maturity securities | 223 | 161
Equity securities: |  |
Equity securities | 198 | 219
Short-term and other | 1,852 | 1,976
Total assets | 2,273 | 2,356
Other liabilities | 0 | 0
Total liabilities | 0 | 0
Level 1 | Corporate and other bonds |  |
Fixed maturity securities: |  |
Fixed maturity securities | 223 | 161
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 | 162 | 167
Level 1 | Non-redeemable preferred stock |  |
Equity securities: |  |
Equity securities | 36 | 52
Level 2 |  |
Fixed maturity securities: |  |
Fixed maturity securities | 38,692 | 38,274
Equity securities: |  |
Equity securities | 441 | 440
Short-term and other | 70 | 32
Total assets | 39,203 | 38,746
Other liabilities | 0 | 1
Total liabilities | 0 | 1
Level 2 | Corporate and other bonds |  |
Fixed maturity securities: |  |
Fixed maturity securities | 24,340 | 23,926
Level 2 | States, municipalities and political subdivisions |  |
Fixed maturity securities: |  |
Fixed maturity securities | 6,762 | 7,348
Level 2 | Asset-backed |  |
Fixed maturity securities: |  |
Fixed maturity securities | 7,590 | 7,000
Level 2 | Common Stock |  |
Equity securities: |  |
Equity securities | 0 | 0
Level 2 | Non-redeemable preferred stock |  |
Equity securities: |  |
Equity securities | 441 | 440
Level 3 |  |
Fixed maturity securities: |  |
Fixed maturity securities | 2,196 | 1,990
Equity securities: |  |
Equity securities | 20 | 24
Short-term and other | 0 | 0
Total assets | 2,216 | 2,014
Other liabilities | 0 | 0
Total liabilities | 0 | 0
Level 3 | Corporate and other bonds |  |
Fixed maturity securities: |  |
Fixed maturity securities | 1,278 | 1,045
Level 3 | States, municipalities and political subdivisions |  |
Fixed maturity securities: |  |
Fixed maturity securities | 42 | 44
Level 3 | Asset-backed |  |
Fixed maturity securities: |  |
Fixed maturity securities | 876 | 901
Level 3 | Common Stock |  |
Equity securities: |  |
Equity securities | 18 | 24
Level 3 | Non-redeemable preferred stock |  |
Equity securities: |  |
Equity securities | $ 2 | $ 0

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