Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	Apr. 28, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Trading Symbol	CARS
Document Fiscal Period Focus	Q1
Entity Registrant Name	Cars.com Inc.
Entity Central Index Key	0001683606
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-37869
Entity Tax Identification Number	81-3693660
Entity Address, Address Line One	300 S. Riverside Plaza
Entity Address, Address Line Two	Suite 1000
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60606
City Area Code	312
Local Phone Number	601-5000
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock
Security Exchange Name	NYSE
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock Shares Outstanding		69,492,015