Property, Plant and Equipment, Net - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 70,685	$ 68,630
Less: Accumulated depreciation	(15,392)	(10,483)
Property, plant and equipment, net	55,293	58,147
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	21,575	18,073
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,856	7,525
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,664	1,648
Software, computer and other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,025	7,772
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	30,029	29,720
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,536	$ 3,892