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v3.23.3

Segment Information (Selected Information And Details For MMC's Operating Segments) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 5,382 | $ 4,770 | $ 17,182 | $ 15,698
Operating Income/(Loss) | 996 | 791 | 4,179 | 3,600
Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 5,396 | 4,789 | 17,227 | 15,745
Operating Income/(Loss) | 1,064 | 879 | 4,415 | 3,834
Operating Segments | Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 3,190 | 2,838 | 10,818 | 9,700
Operating Income/(Loss) | 640 | 529 | 3,192 | 2,617
Interest on fiduciary funds | 131 | 40 | 330 | 57
Equity method investment income | 3 |  | 14 | 9
Loss on consolidation of business |  |  |  | 27
Operating Segments | Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,206 | 1,951 | 6,409 | 6,045
Operating Income/(Loss) | 424 | 350 | 1,223 | 1,217
Operating Segments | Small Individual Financial Advisory Business |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Pre-tax loss on sale |  |  | 17 |
Corporate/Eliminations |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | (14) | (19) | (45) | (47)
Operating Income/(Loss) | (68) | (88) | (236) | (234)
Intersegment Eliminations | Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue |  |  | 5 | 5
Intersegment Eliminations | Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 14 | $ 19 | $ 40 | $ 42

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