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v3.23.2

Segment Information (Details of Operating Segment Revenue) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 5,876 | $ 5,379 | $ 11,800 | $ 10,928
Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 3,722 | 3,313 | 7,628 | 6,862
Risk and Insurance Services | Marsh |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 3,038 | 2,778 | 5,782 | 5,324
Risk and Insurance Services | Guy Carpenter |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 576 | 522 | 1,647 | 1,521
Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,172 | 2,084 | 4,203 | 4,094
Consulting | Mercer |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 1,374 | 1,389 | 2,718 | 2,732
Consulting | Oliver Wyman Group |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 798 | 695 | 1,485 | 1,362
Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 5,894 | 5,397 | 11,831 | 10,956
Operating Segments | Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 3,722 | 3,313 | 7,628 | 6,862
Operating Segments | Risk and Insurance Services | Marsh |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 3,103 | 2,787 | 5,903 | 5,336
Operating Segments | Risk and Insurance Services | Guy Carpenter |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 619 | 526 | 1,725 | 1,526
Operating Segments | Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,172 | 2,084 | 4,203 | 4,094
Operating Segments | Consulting | Mercer |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 1,374 | 1,389 | 2,718 | 2,732
Operating Segments | Consulting | Oliver Wyman Group |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 798 | 695 | 1,485 | 1,362
Corporate/Eliminations |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ (18) | $ (18) | $ (31) | $ (28)

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