Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 05, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Trading Symbol	VRM
Entity Registrant Name	VROOM, INC.
Entity Central Index Key	0001580864
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Stock, $0.001 par value
Security Exchange Name	NASDAQ
Entity File Number	001-39315
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	90-1112566
Entity Address, Address Line One	1375 Broadway
Entity Address, Address Line Two	Floor 11
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10018
City Area Code	855
Local Phone Number	524-1300
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		136,907,849