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Investments (Evaluation of Fixed Maturity Securities AFS in an Unrealized Loss Position- Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2024 | Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 28,100 |
Equal to or Greater than 12 Months Gross Unrealized Loss | 26,175 | $ 24,394
Below Investment Grade |  |
Debt Securities, Available-for-sale [Line Items] |  |
Equal to or Greater than 12 Months Gross Unrealized Loss | 769 | $ 719
Fixed maturity securities without an allowance for credit loss |  |
Debt Securities, Available-for-sale [Line Items] |  |
Change in Gross Unrealized Temporary Loss | $ 2,300 |

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