Revenue - Disaggregated by Timing of Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue
Revenue	$ 42,031	$ 37,503
Point in time
Disaggregation of Revenue
Revenue	40,846	35,665
Over time
Disaggregation of Revenue
Revenue	$ 1,185	$ 1,838