Earnings Per Share - Schedule of Computation of Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net income attributable to AdTheorent Holding Company, Inc.	$ 7	$ 29,338
Weighted-average common shares outstanding - basic	87,984,917	86,222,972
Effect of dilutive equity-based awards	4,480,586	6,398,850
Weighted-average common shares outstanding - diluted	92,465,503	92,621,822
Basic	$ 0	$ 0.34
Diluted	$ 0	$ 0.32