Segment and Geographic Information - Geographic Locations (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 51,373	$ 31,509
North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	39,257	18,505
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	9,797	11,533
Rest of World
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 2,319	$ 1,471