Document and Entity Information
Document and Entity Information | Oct. 27, 2022 |
Document And Entity Information [Line Items] | |
Document Type | 8-K |
Document Period End Date | Oct. 27, 2022 |
Entity Registrant Name | Marsh & McLennan Companies, Inc. |
Entity Incorporation, State or Country Code | DE |
Entity File Number | 1-5998 |
Entity Tax Identification Number | 36-2668272 |
Entity Address, Address Line One | 1166 Avenue of the Americas |
Entity Address, City or Town | New York |
Entity Address, State or Province | NY |
Entity Address, Postal Zip Code | 10036 |
City Area Code | 212 |
Local Phone Number | 345-5000 |
Written Communications | false |
Soliciting Material | false |
Pre-commencement Tender Offer | false |
Pre-commencement Issuer Tender Offer | false |
Entity Emerging Growth Company | false |
Amendment Flag | false |
Entity Central Index Key | 0000062709 |
NEW YORK STOCK EXCHANGE, INC. [Member] | |
Document And Entity Information [Line Items] | |
Title of 12(b) Security | Common Stock, par value $1.00 per share |
Trading Symbol | MMC |
Security Exchange Name | NYSE |
CHICAGO STOCK EXCHANGE, INC [Member] | |
Document And Entity Information [Line Items] | |
Title of 12(g) Security | Common Stock, par value $1.00 per share |
Trading Symbol | MMC |
Security Exchange Name | CHX |