The Company and Basis of Presentation - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($) Segment	Dec. 31, 2019 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of operating segments | Segment	1
Working capital	$ 130,000
Accumulated deficit	(253,294)	$ (195,115)
Cash, cash equivalents, marketable securities, and restricted cash	$ 141,500