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v3.25.2

Segment Information (Selected Information and Details for MMC's Operating Segments) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 6,974 | $ 6,221 | $ 14,035 | $ 12,694
Compensation and benefits | 3,895 | 3,454 | 7,745 | 6,924
Depreciation and amortization expense | 91 | 87 | 179 | 186
Identified intangible amortization expense | 140 | 89 | 279 | 179
Other operating expenses | 1,019 | 949 | 1,998 | 1,838
Operating income | 1,829 | 1,642 | 3,834 | 3,567
Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 6,996 | 6,238 | 14,072 | 12,725
Compensation and benefits | 3,860 | 3,422 | 7,674 | 6,854
Depreciation and amortization expense | 76 | 72 | 150 | 155
Identified intangible amortization expense | 140 | 89 | 279 | 179
Other operating expenses | 1,021 | 948 | 2,001 | 1,833
Operating income | 1,899 | 1,707 | 3,968 | 3,704
Operating Segments | Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 4,625 | 4,022 | 9,387 | 8,295
Compensation and benefits | 2,462 | 2,108 | 4,913 | 4,226
Depreciation and amortization expense | 51 | 46 | 101 | 92
Identified intangible amortization expense | 121 | 77 | 241 | 156
Other operating expenses | 548 | 494 | 1,076 | 959
Operating income | 1,443 | 1,297 | 3,056 | 2,862
Interest on fiduciary funds | 99 | 125 | 202 | 247
Equity method investment income (loss) | 15 | 10 | 15 | 10
Operating Segments | Risk and Insurance Services | Disposal Group, Disposed of by Sale, Not Discontinued Operations |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net gain included in revenue consolidated statements of income |  |  | 28 |
Operating Segments | Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 2,371 | 2,216 | 4,685 | 4,430
Compensation and benefits | 1,398 | 1,314 | 2,761 | 2,628
Depreciation and amortization expense | 25 | 26 | 49 | 63
Identified intangible amortization expense | 19 | 12 | 38 | 23
Other operating expenses | 473 | 454 | 925 | 874
Operating income | 456 | 410 | 912 | 842
Operating Segments | Consulting | U.S. Health And Benefits And U.K Pension Administration Businesses |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net gain included in revenue consolidated statements of income |  |  |  | 21
Corporate/Eliminations |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | (22) | (17) | (37) | (31)
Compensation and benefits | 35 | 32 | 71 | 70
Depreciation and amortization expense | 15 | 15 | 29 | 31
Identified intangible amortization expense | 0 | 0 | 0 | 0
Other operating expenses | (2) | 1 | (3) | 5
Operating income | (70) | (65) | (134) | (137)
Intersegment Eliminations | Risk and Insurance Services |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | 4 | 4 | 5 | 5
Intersegment Eliminations | Consulting |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Revenue | $ 18 | $ 13 | $ 33 | $ 26

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