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v3.23.2

Segment Information (Selected Information And Details For MMC's Operating Segments) (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
Operating Income (Loss) | 1,457 | 1,364 | 3,183 | 2,809
Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 3,722 | 3,313 | 7,628 | 6,862
Interest on fiduciary funds | 108 | 13 | 199 | 17
Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,172 | 2,084 | 4,203 | 4,094
Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 5,894 | 5,397 | 11,831 | 10,956
Operating Income (Loss) | 1,545 | 1,442 | 3,351 | 2,955
Operating Segments | Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 3,722 | 3,313 | 7,628 | 6,862
Operating Income (Loss) | 1,157 | 967 | 2,552 | 2,088
Interest on fiduciary funds | 108 | 13 | 199 | 17
Equity method investment income | 12 | 7 | 11 | 8
Loss on consolidation of business |  |  |  | 27
Operating Segments | Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,172 | 2,084 | 4,203 | 4,094
Operating Income (Loss) | 388 | 475 | 799 | 867
Operating Segments | Mercer U.S. Affinity Business |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Pre-tax loss on sale |  | 112 |  | 112
Operating Segments | Small Individual Financial Advisory Business |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Pre-tax loss on sale |  |  | (17) |
Operating Segments | Oliver Wyman Group |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Loss on consolidation of business |  |  |  | 12
Corporate/Eliminations |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | (18) | (18) | (31) | (28)
Operating Income (Loss) | (88) | (78) | (168) | (146)
Intersegment Eliminations | Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 5 | 5 | 5 | 5
Intersegment Eliminations | Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 13 | $ 13 | $ 26 | $ 23

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