Revenue Recognition - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregated revenue	$ 587	$ 1,240	$ 2,056	$ 3,091
Product revenue
Disaggregated revenue	0	0	1,247	199
License and royalty revenue
Disaggregated revenue	572	0	784	0
Contract revenue
Disaggregated revenue	15	1,240	25	2,892
Transferred at Point in Time
Disaggregated revenue	572	36	2,035	251
Transferred at Point in Time | Product revenue
Disaggregated revenue	0	0	1,247	199
Transferred at Point in Time | License and royalty revenue
Disaggregated revenue	572	0	784	0
Transferred at Point in Time | Contract revenue
Disaggregated revenue	0	36	4	52
Transferred over Time
Disaggregated revenue	15	1,204	21	2,840
Transferred over Time | Product revenue
Disaggregated revenue	0	0	0	0
Transferred over Time | License and royalty revenue
Disaggregated revenue	0	0	0	0
Transferred over Time | Contract revenue
Disaggregated revenue	$ 15	$ 1,204	$ 21	$ 2,840