Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 61,921	$ 9,643
Less: accumulated depreciation	(5,472)	(1,048)
Total property and equipment, net	56,449	8,595
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	13,117	5,534
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	29,924	15
Computers equipment and purchased software
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	3,726	1,327
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	2,764	64
Construction in Progress
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 12,390	$ 2,703

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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