Balance Sheet Components - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Total property, plant and equipment, gross	$ 11,457	$ 5,146
Less: Accumulated depreciation	(1,729)	(1,264)
Total property, plant and equipment, net	9,728	3,882
Laboratory Equipment
Property Plant And Equipment [Line Items]
Total property, plant and equipment, gross	4,895	3,800
Office Equipment
Property Plant And Equipment [Line Items]
Total property, plant and equipment, gross	150	150
Leasehold Improvement
Property Plant And Equipment [Line Items]
Total property, plant and equipment, gross	96	78
Construction In Progress
Property Plant And Equipment [Line Items]
Total property, plant and equipment, gross	$ 6,316	$ 1,118