Other Balance Sheet Details (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 58,740	$ 41,607
Less: accumulated depreciation and amortization	(17,416)	(11,681)
Property and equipment, net	41,324	29,926
Depreciation and amortization	5,682	3,930	$ 2,359
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	24,737	17,179
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,870	4,639
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	15,953	13,888
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,089	0
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 12,091	$ 5,901

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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