| Document and Entity Information | Oct. 29, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | CBIZ, Inc. |
| Document Type | 8-K |
| Amendment Flag | false |
| Entity Central Index Key | 0000944148 |
| Document Period End Date | Oct. 29, 2020 |
| Entity Emerging Growth Company | false |
| Entity File Number | 001-32961 |
| Entity Incorporation State Country Code | DE |
| Entity Tax Identification Number | 22-2769024 |
| Entity Address, Address Line One | 6050 Oak Tree Boulevard |
| Entity Address, Address Line Two | South |
| Entity Address, Address Line Three | Suite 500 |
| Entity Address, City or Town | Cleveland |
| Entity Address, State or Province | OH |
| Entity Address, Postal Zip Code | 44131 |
| City Area Code | 216 |
| Local Phone Number | 447-9000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock par value $0.01 per share |
| Trading Symbol | CBZ |
| Security Exchange Name | NYSE |
