Investments - Carrying amounts of other invested assets (Details) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
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|---|---|---|---|---|
| Investments [Line Items] | ||||
| Alternative investments | $ 11,320 | $ 11,809 | ||
| Investment real estate | 2,237 | 2,153 | ||
| All other investments | 2,660 | 1,991 | ||
| Other invested assets | [1] | 16,217 | 15,953 | |
| Accumulated depreciation on investment in real estate | 853 | 786 | ||
| Fortitude Re Funds Withheld Assets | ||||
| Investments [Line Items] | ||||
| Other invested assets | 156 | 156 | ||
| DaVinciRe Holdings Ltd | ||||
| Investments [Line Items] | ||||
| Other invested assets | 300 | |||
| Hedge Funds | ||||
| Investments [Line Items] | ||||
| Other invested assets | 700 | 1,400 | ||
| Private equity funds | ||||
| Investments [Line Items] | ||||
| Alternative investments | 8,798 | 8,428 | ||
| Other invested assets | $ 10,600 | $ 10,400 | ||
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