Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Oct. 21, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
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
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
Title of 12(b) Security	Common Stock, $0.01 Par Value
Trading Symbol	CBZ
Security Exchange Name	NYSE
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 Common Stock, Shares Outstanding		52,092,215
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000944148
Current Fiscal Year End Date	--12-31