Document and Entity Information - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Jul. 31, 2021
Cover [Abstract]
Document Period End Date		Jun. 30, 2021
Entity Common Stock, Shares Outstanding (in shares)			33,040,112
Entity Shell Company		false
Amendment Flag		false
Document Fiscal Year Focus		2021
Document Fiscal Period Focus		Q1
Entity Central Index Key		0001666071
Current Fiscal Year End Date		--12-31
Document Type		10-Q
Document Quarterly Report		true
Document Transition Report		false
Entity File Number		001-38386
Entity Registrant Name		CARDLYTICS, INC.
Entity Tax Identification Number		26-3039436
Entity Incorporation, State or Country Code		DE
Entity Address, Postal Zip Code		30308
Entity Address, State or Province		GA
Entity Address, City or Town		Atlanta
Entity Address, Address Line One		675 Ponce de Leon Ave. NE, Ste 6000
Local Phone Number		792-5802
City Area Code		(888)
Title of 12(b) Security		Common Stock
Trading Symbol		CDLX
Security Exchange Name		NASDAQ
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