Revenue - Revenue from External Customers by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 65,010	$ 103,171	$ 125,935	$ 200,572
China
Disaggregation of Revenue [Line Items]
Total revenue	24,940	62,665	40,183	121,574
Americas
Disaggregation of Revenue [Line Items]
Total revenue	5,997	16,080	11,188	34,421
Rest of world
Disaggregation of Revenue [Line Items]
Total revenue	$ 34,073	$ 24,426	$ 74,564	$ 44,577