Segment Information - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2023	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Revenues	$ 59,472	$ 35,404	$ 21,223	$ 56,627	$ 116,099	$ 157,110	$ 89,360
Sell-side advertising
Segment Reporting Information [Line Items]
Revenues						122,434	60,011
Buy-side advertising
Segment Reporting Information [Line Items]
Revenues						$ 34,676	$ 29,349