Earnings Per Share - Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net income attributable to shareholders of Criteo S.A.	$ 15,459	$ 19,120
Weighted average number of shares outstanding (in shares)	61,691,001	64,336,777
Dilutive effect of :
Restricted share awards (RSU's) (in shares)	264,309	1,317,350
Share options and (BSPCEs) (in shares)	153,786	336,647
Share warrants (in shares)	16,486	50,522
Weighted average number of shares outstanding used to determine diluted earnings per share (in shares)	62,125,582	66,041,296
Diluted earnings per share (in USD per share)	$ 0.25	$ 0.29