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Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) - USD ($) $ in Millions | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Fixed maturity securities: |  |  |
Fixed maturity securities | $ 37,856 | $ 37,627 | [1]
Equity securities: |  |  |
Equity securities | 692 | 674 | [1]
Short term and other | 1,791 | 1,679 |
Total assets | 40,339 | 39,980 |
Other liabilities | 1 | 1 |
Total liabilities | 1 | 1 |
Corporate and other bonds |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 23,320 | 22,117 |
States, municipalities and political subdivisions |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 7,034 | 8,317 |
Asset-backed |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 7,502 | 7,193 |
Common Stock |  |  |
Equity securities: |  |  |
Equity securities | 213 | 185 |
Non-redeemable preferred stock |  |  |
Equity securities: |  |  |
Equity securities | 479 | 489 |
Level 1 |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 159 | 120 |
Equity securities: |  |  |
Equity securities | 242 | 204 |
Short term and other | 1,756 | 1,608 |
Total assets | 2,157 | 1,932 |
Other liabilities | 0 | 0 |
Total liabilities | 0 | 0 |
Level 1 | Corporate and other bonds |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 159 | 120 |
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 | 190 | 150 |
Level 1 | Non-redeemable preferred stock |  |  |
Equity securities: |  |  |
Equity securities | 52 | 54 |
Level 2 |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 35,814 | 35,866 |
Equity securities: |  |  |
Equity securities | 427 | 435 |
Short term and other | 35 | 71 |
Total assets | 36,276 | 36,372 |
Other liabilities | 1 | 1 |
Total liabilities | 1 | 1 |
Level 2 | Corporate and other bonds |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 22,216 | 21,187 |
Level 2 | States, municipalities and political subdivisions |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 6,993 | 8,274 |
Level 2 | Asset-backed |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 6,605 | 6,405 |
Level 2 | Common Stock |  |  |
Equity securities: |  |  |
Equity securities | 0 | 0 |
Level 2 | Non-redeemable preferred stock |  |  |
Equity securities: |  |  |
Equity securities | 427 | 435 |
Level 3 |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 1,883 | 1,641 |
Equity securities: |  |  |
Equity securities | 23 | 35 |
Short term and other | 0 | 0 |
Total assets | 1,906 | 1,676 |
Other liabilities | 0 | 0 |
Total liabilities | 0 | 0 |
Level 3 | Corporate and other bonds |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 945 | 810 |
Level 3 | States, municipalities and political subdivisions |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 41 | 43 |
Level 3 | Asset-backed |  |  |
Fixed maturity securities: |  |  |
Fixed maturity securities | 897 | 788 |
Level 3 | Common Stock |  |  |
Equity securities: |  |  |
Equity securities | 23 | 35 |
Level 3 | Non-redeemable preferred stock |  |  |
Equity securities: |  |  |
Equity securities | $ 0 | $ 0 |
[1] | As of January 1, 2023, the Company adopted ASU 2018-12 using the modified retrospective method applied as of the transition date of January 1, 2021. Prior period amounts in the financial statements have been adjusted to reflect application of the new guidance. See Note A to the Condensed Consolidated Financial Statements for additional information.

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