Revenue - Disaggregated by Timing of Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue
Revenue	$ 10,120	$ 9,178	$ 32,054	$ 27,850
Point in time
Disaggregation of Revenue
Revenue	9,756	8,525	30,982	26,156
Over time
Disaggregation of Revenue
Revenue	$ 364	$ 653	$ 1,072	$ 1,694