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v3.23.1

Segment Information (Selected Information And Details For MMC's Operating Segments) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Segment Reporting Information [Line Items] |  |
Revenue | $ 5,924 | $ 5,549
Operating Income (Loss) | 1,726 | 1,445
Loss on deconsolidation of russian businesses | 0 | 39
Risk and Insurance Services |  |
Segment Reporting Information [Line Items] |  |
Revenue | 3,906 | 3,549
Interest on fiduciary funds | 91 | 4
Consulting |  |
Segment Reporting Information [Line Items] |  |
Revenue | 2,031 | 2,010
Operating Segments |  |
Segment Reporting Information [Line Items] |  |
Revenue | 5,937 | 5,559
Operating Income (Loss) | 1,806 | 1,513
Operating Segments | Risk and Insurance Services |  |
Segment Reporting Information [Line Items] |  |
Revenue | 3,906 | 3,549
Operating Income (Loss) | 1,395 | 1,121
Interest on fiduciary funds | 91 | 4
Loss on deconsolidation of russian businesses |  | 27
Operating Segments | Consulting |  |
Segment Reporting Information [Line Items] |  |
Revenue | 2,031 | 2,010
Operating Income (Loss) | 411 | 392
Loss on deconsolidation of russian businesses |  | 12
Operating Segments | Small Individual Financial Advisory Business |  |
Segment Reporting Information [Line Items] |  |
Pre-tax loss on sale | 19 |
Corporate/Eliminations |  |
Segment Reporting Information [Line Items] |  |
Revenue | (13) | (10)
Operating Income (Loss) | (80) | (68)
Intersegment Eliminations | Consulting |  |
Segment Reporting Information [Line Items] |  |
Revenue | $ 13 | $ 10

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