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Investment Information - Other investments (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
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Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | $ 2,488 | $ 1,644
Other investments |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | 1,777 | 1,043
Fixed maturities |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | 683 | 554
Equity securities |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | 7 | 14
Short-term investments |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Other investments | $ 21 | $ 33

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