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Supplemental Disclosures to the Consolidated Statements of Cash Flows - Narrative (Details) - USD ($) $ in Millions | 1 Months Ended | 12 Months Ended
--- | --- | ---
Oct. 31, 2023 | Dec. 31, 2023 | Dec. 31, 2022
Loss Contingencies [Line Items] |  |  |
Litigation settlement, expense |  |  | $ 30
Risk and Insurance Services | Guy Carpenter |  |  |
Loss Contingencies [Line Items] |  |  |
Gain from the settlement | $ 58 | $ 58 |
Litigation settlement, expense | $ 10 |  |

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