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Investments (Net Realized Gains (Losses) And Losses Included In Net Realized Gains (Losses) And Other Comprehensive Income) (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Gain (Loss) on Securities [Line Items] |  |  |  |
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease) |  | $ (214) | $ (237) |
Foreign exchange gains( losses) |  | (183) | 397 | $ 340
Derivative, Gain (Loss) on Derivative, Net |  | (252) | 133 |
Net realized gains (losses) |  | (607) | (1,085) | 1,030
Unrealized Gain (Loss) on Investments |  | 3,120 | (9,535) | (2,417)
Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax |  | (328) | 1,043 | 521
Other derivative instruments |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Derivative, Gain (Loss) on Derivative, Net |  | (10) | (11) | (8)
Investment and embedded derivative instruments |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Derivative, Gain (Loss) on Derivative, Net |  | (53) | (43) | (72)
Fixed Maturities [Member] |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Debt Securities, Available-for-sale, Realized Gain (Loss), Excluding Other-than-temporary Impairment |  | 208 | 619 | 142
Debt Securities, Available-for-sale, Realized Loss, Excluding Other-than-temporary Impairment |  | (656) | (1,379) | (123)
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease) |  | 43 | 154 | 14
Debt Securities, Available-For-Sale, Credit Impairment Charges Intent to Sell | [1] | (64) | (135) | (30)
Debt Securities, Available-for-sale, Realized Gain (Loss) |  | (481) | (1,049) | 3
Equity Securities [Member] |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Equity Securities, FV-NI, Realized Gain (Loss) |  | (38) | (230) | 662
Unrealized Gain (Loss) on Investments |  | 30 | (639) | 505
Other Investments |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Net realized gains (losses) |  | (12) | 0 | 0
Unrealized Gain (Loss) on Investments |  | (12) |  |
Available-for-sale Securities [Member] |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Unrealized Gain (Loss) on Investments |  | 3,563 | (10,583) | (2,901)
Fixed maturities held to maturity |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Unrealized Gain (Loss) on Investments |  | (125) | (15) | (18)
Other [Member] |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Gain (Loss) on Sale of Other Investments |  | 88 | (118) | (6)
Unrealized Gain (Loss) on Investments |  | 10 | 20 | (19)
Equity securities and other investments [Member] |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Net realized gains (losses) |  | 20 | (261) | 773
Unrealized Gain (Loss) on Investments |  | 88 | (670) | 616
Private equities |  |  |  |
Gain (Loss) on Securities [Line Items] |  |  |  |
Net realized gains (losses) |  | 70 | (31) | 111
Unrealized Gain (Loss) on Investments |  | $ 70 | $ (31) | $ 111
[1] | Relates to certain securities we intended to sell and securities written to market entering default.

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