Segment Information - Geographic region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Segment Information
Total revenue	$ 17,565	$ 15,693	$ 13,749	$ 10,417	$ 14,649	$ 12,451	$ 11,050	$ 13,196	$ 57,424	$ 51,346
US
Segment Information
Total revenue									57,201	51,124
Europe
Segment Information
Total revenue									$ 223	$ 222