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Investments (Supplemental Net Investment Income) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2024 | Mar. 31, 2023
Net Investment Income [Line Items] |  |
Debt and Equity Securities, Realized Gain (Loss) | $ (67) | $ (508)
Equity Securities, FV-NI, Unrealized Gain (Loss) | 30 | 41
Income (Loss) from Equity Method Investments | 210 | (93)
Net investment income |  |
Net Investment Income [Line Items] |  |
Debt and Equity Securities, Realized Gain (Loss) | 68 | 38
Debt and Equity Securities, Unrealized Gain (Loss) | 580 | 322
Debt and Equity Securities, Gain (Loss) | 648 | 360
Unit-linked investments |  |
Net Investment Income [Line Items] |  |
Equity Securities, FV-NI, Unrealized Gain (Loss) | $ 537 | $ 313

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