Balance Sheet Components - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Depreciation	$ 4,300,000	$ 4,400,000	$ 3,400,000
Loss on impairment of intangible assets	5,006,000	3,992,000
Lab Equipment
Property Plant And Equipment [Line Items]
Loss on impairment of intangible assets	$ 1,200,000	$ 0