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v3.22.2

Segment Information (Selected Information And Details For MMC's Operating Segments) (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended
--- | --- | --- | ---
Apr. 30, 2022 | Jun. 30, 2022 | Mar. 31, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | $ 5,379 |  | $ 5,017 | $ 10,928 | $ 10,100
Operating Income (Loss) |  | 1,364 |  | 1,228 | 2,809 | 2,586
Loss on deconsolidation of Russian businesses |  |  | $ 39 |  | 39 | 0
U.S. Affinity Business |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Gain on disposal | $ 112 |  |  |  |  |
Risk and Insurance Services Segment |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | 3,313 |  | 3,141 | 6,862 | 6,366
Interest on fiduciary funds |  | 13 |  | 3 | 17 | 8
Consulting Segment |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | 2,084 |  | 1,892 | 4,094 | 3,765
Operating Segments |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | 5,397 |  | 5,033 | 10,956 | 10,131
Operating Income (Loss) |  | 1,442 |  | 1,294 | 2,955 | 2,715
Operating Segments | Risk and Insurance Services Segment |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | 3,313 |  | 3,141 | 6,862 | 6,366
Operating Income (Loss) |  | 967 |  | 950 | 2,088 | 2,010
Interest on fiduciary funds |  | 13 |  | 3 | 17 | 8
Equity method income (loss) |  | 7 |  | 14 | 8 | 17
Loss on deconsolidation of Russian businesses |  |  |  |  | 27 |
Gain (loss) on consolidation of business |  |  |  | 51 |  | 53
Operating Segments | Consulting Segment |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | 2,084 |  | 1,892 | 4,094 | 3,765
Operating Income (Loss) |  | 475 |  | 344 | 867 | 705
Loss on deconsolidation of Russian businesses |  |  |  |  | 12 |
Corporate/Eliminations |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | (18) |  | (16) | (28) | (31)
Operating Income (Loss) |  | (78) |  | (66) | (146) | (129)
Intersegment Eliminations | Risk and Insurance Services Segment |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | 5 |  | 4 | 5 | 4
Intersegment Eliminations | Consulting Segment |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |
Revenue |  | 13 |  | $ 12 | 23 | $ 27
Gain on disposal |  | $ 112 |  |  | $ 112 |

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