Earnings Per Share - Basic (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
Basic earnings per share (in USD per share)	$ 0.25	$ 0.30