Revenue - Disaggregated by Timing of Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue
Revenue	$ 14,795	$ 10,120	$ 36,923	$ 32,054
Point in time
Disaggregation of Revenue
Revenue	13,618	9,756	34,212	30,982
Over time
Disaggregation of Revenue
Revenue	$ 1,177	$ 364	$ 2,711	$ 1,072