Redeemable Convertible Preferred Stock Warrants - Additional Information (Details) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended
	Jun. 30, 2017 USD ($) $ / shares shares	Sep. 30, 2020 shares	Jun. 30, 2019 shares	Sep. 30, 2020 shares	Jun. 24, 2019 USD ($) shares	Dec. 31, 2018 USD ($)	Sep. 30, 2014 $ / shares shares
Convertible Preferred Stock Warrants [Line Items]
Warrant issued to purchase stock					188,643
Fair values of convertible preferred stock warrants | $						$ 0.7
Fair value transferred to additional paid-in capital | $					$ 2.1
Warrant exercised		62,096	22,489
Common stock issued for exercise of warrant			19,069	40,357
Series B Redeemable Convertible Preferred Stock | Term Loan
Convertible Preferred Stock Warrants [Line Items]
Warrant issued to purchase stock							22,489
Warrant exercise price per share | $ / shares							$ 4.60
Series C Redeemable Convertible Preferred Stock | Revolving Loan
Convertible Preferred Stock Warrants [Line Items]
Warrant issued to purchase stock	62,096
Warrant exercise price per share | $ / shares	$ 8.052
Estimated fair value of warrants | $	$ 0.1
Contractual term	7 years
Series C Redeemable Convertible Preferred Stock | Revolving Loan | Risk-free Interest Rate
Convertible Preferred Stock Warrants [Line Items]
Warrants and rights outstanding, measurement input	1.97
Series C Redeemable Convertible Preferred Stock | Revolving Loan | Volatility
Convertible Preferred Stock Warrants [Line Items]
Warrants and rights outstanding, measurement input	64.33
Series C Redeemable Convertible Preferred Stock | Revolving Loan | Dividend Yield
Convertible Preferred Stock Warrants [Line Items]
Warrants and rights outstanding, measurement input	0