Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Feb. 19, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-32961
Entity Registrant Name	CBIZ, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-2769024
Entity Address, Address Line One	6050 Oak Tree Boulevard,
Entity Address, Address Line Two	South, 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
Title of 12(b) Security	Common Stock, $0.01 Par Value
Trading Symbol	CBZ
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 1.2
Entity Common Stock, Shares Outstanding		53,491,503
Documents Incorporated by Reference	The registrant incorporates by reference in Part III hereof portions of its definitive Proxy Statement for its 2021 Annual Meeting of Stockholders.
ICFR Auditor Attestation Flag	true
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0000944148