Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 12,157	$ 7,586	$ 29,451	$ 15,957
United States
Disaggregation of Revenue [Line Items]
Total revenue	2,033	1,959	5,910	3,403
Greater China
Disaggregation of Revenue [Line Items]
Total revenue	7,591	4,548	17,800	9,868
Rest of North America
Disaggregation of Revenue [Line Items]
Total revenue	1,286	167	2,513	525
South America
Disaggregation of Revenue [Line Items]
Total revenue	409	214	1,004	483
Rest of Asia Pacific
Disaggregation of Revenue [Line Items]
Total revenue	127	455	701	1,168
Europe
Disaggregation of Revenue [Line Items]
Total revenue	$ 711	$ 243	$ 1,523	$ 510