| Cover | Apr. 29, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Apr. 29, 2021 |
| Entity Registrant Name | CBRE GROUP, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-32205 |
| Entity Tax Identification Number | 94-3391143 |
| Entity Address, Address Line One | 2100 McKinney Avenue |
| Entity Address, Address Line Two | Suite 1250 |
| Entity Address, State or Province | TX |
| Entity Address, City or Town | Dallas |
| Entity Address, Postal Zip Code | 75201 |
| Local Phone Number | 979-6100 |
| City Area Code | (214) |
| Title of 12(b) Security | Class A Common Stock, $0.01 par value per share |
| Trading Symbol | “CBRE” |
| Security Exchange Name | NYSE |
| 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 | 0001138118 |
| Amendment Flag | false |
