| Cover Page | Feb. 13, 2024 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Feb. 13, 2024 |
| Entity Registrant Name | GCM Grosvenor Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-39716 |
| Entity Tax Identification Number | 85-2226287 |
| Entity Address, Address Line One | 900 North Michigan Avenue |
| Entity Address, Address Line Two | Suite 1100 |
| Entity Address, City or Town | Chicago |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60611 |
| City Area Code | 312 |
| Local Phone Number | 506-6500 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001819796 |
| Amendment Flag | false |
| Common Stock [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Class A common stock, par value $0.0001 per share |
| Trading Symbol | GCMG |
| Security Exchange Name | NASDAQ |
| Warrant [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Warrants to purchase one share of Class A common stock |
| Trading Symbol | GCMGW |
| Security Exchange Name | NASDAQ |
