Segment and Geographic Information - Schedule of Product Revenue Based on Location (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues From External Customers And Long Lived Assets [Line Items]
Product revenue	$ 19,590	$ 11,333	$ 45,073	$ 28,615
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Product revenue	11,144	6,246	24,450	15,054
Germany
Revenues From External Customers And Long Lived Assets [Line Items]
Product revenue	1,185	873	2,921	2,389
Rest of Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Product revenue	5,592	3,428	13,807	9,473
All Other Countries
Revenues From External Customers And Long Lived Assets [Line Items]
Product revenue	$ 1,669	$ 786	$ 3,895	$ 1,699