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Investments - Internally Managed Investment Portfolio (Details) - USD ($) $ in Millions | Mar. 31, 2026 | Dec. 31, 2025
--- | --- | ---
Debt and Equity Securities, FV-NI [Line Items] |  |
Estimated fair value | $ 6,875 | $ 6,369
Fixed-maturity securities, trading | 127 | 124
Short-term investments, at fair value | 768 | 903
Other invested assets | 1,136 | 1,091
Total investments | 8,906 | 8,487
Sound Point Capital Management, LP |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Equity method investments | 406 | 415
Total investments | 549 | 628
Equity method investments |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Equity method investments | 685 | 664
Other |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Other invested assets | $ 45 | $ 12

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