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Investment Information - Other investments (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | $ 3,066 | $ 2,488
Other investments |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | 2,135 | 1,777
Fixed maturities |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | 854 | 683
Equity securities |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | 7 | 7
Short-term investments |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | $ 70 | $ 21

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