Revenue - Revenue from External Customers by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 60,926	$ 97,401
China
Disaggregation of Revenue [Line Items]
Total revenue	15,244	58,909
Americas
Disaggregation of Revenue [Line Items]
Total revenue	5,191	18,340
Rest of world
Disaggregation of Revenue [Line Items]
Total revenue	$ 40,491	$ 20,152