Balance Sheet Details - Schedule of Property, Plant and Equipment, net (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,087	$ 471
Less: accumulated depreciation	(225)	(8)
Total property, plant and equipment, net	862	463
Computer Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	304	152
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	729	306
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 54	$ 13