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v3.22.2.2

Segment Information (Details of Operating Segment Revenue) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 4,770 | $ 4,583 | $ 15,698 | $ 14,683
Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,838 | 2,670 | 9,700 | 9,036
Risk and Insurance Services | Marsh |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,470 | 2,352 | 7,794 | 7,327
Risk and Insurance Services | Guy Carpenter |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 328 | 314 | 1,849 | 1,697
Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 1,951 | 1,925 | 6,045 | 5,690
Consulting | Mercer |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 1,284 | 1,315 | 4,016 | 3,877
Consulting | Oliver Wyman Group |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 667 | 610 | 2,029 | 1,813
Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 4,789 | 4,595 | 15,745 | 14,726
Operating Segments | Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,838 | 2,670 | 9,700 | 9,036
Operating Segments | Risk and Insurance Services | Marsh |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,497 | 2,355 | 7,833 | 7,336
Operating Segments | Risk and Insurance Services | Guy Carpenter |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 341 | 315 | 1,867 | 1,700
Operating Segments | Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 1,951 | 1,925 | 6,045 | 5,690
Operating Segments | Consulting | Mercer |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 1,284 | 1,315 | 4,016 | 3,877
Operating Segments | Consulting | Oliver Wyman Group |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 667 | 610 | 2,029 | 1,813
Corporate/Eliminations |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ (19) | $ (12) | $ (47) | $ (43)

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