Convertible Preferred Stock and Stockholders' Equity - Summary of Assumptions Used to Value Stock Options Granted to Employees using Black-Scholes Option-Pricing (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Convertible Preferred Stock And Stockholders Equity [Abstract]
Risk-free interest rate range	0.46%	1.84%	0.46%
Risk-free interest rate range, minimum				1.84%
Risk-free interest rate range, maximum				2.51%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Expected term of options (years)	6 years 9 months 10 days	6 years 9 months 10 days	6 years 9 months 10 days	6 years 9 months 10 days
Volatility rate range	99.85%	85.02%	99.85%	85.02%