Revenue - Disaggregated by Type (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
Product sales
Disaggregation of Revenue
Revenue	9,577	8,370	30,139	25,396
Royalties
Disaggregation of Revenue
Revenue	179	155	843	760
Other revenue
Disaggregation of Revenue
Revenue	$ 364	$ 653	$ 1,072	$ 1,694