Warrants to acquire shares of Series A convertible preferred stock (Details)	Sep. 30, 2020 $ / shares	Jun. 30, 2020 shares	Jun. 02, 2020 $ / shares
Volatility rate
Class of Warrant or Right [Line Items]
Warrants and Rights Outstanding, Measurement Input	0.819		0.790
Risk-free interest rate
Class of Warrant or Right [Line Items]
Warrants and Rights Outstanding, Measurement Input	0.002		0.002
Expected term (in years)
Class of Warrant or Right [Line Items]
Warrants and Rights Outstanding, Measurement Input	0.027		0.030
Strike price (per share)
Class of Warrant or Right [Line Items]
Warrants and Rights Outstanding, Measurement Input	0.0900		0.0900
Warrants
Class of Warrant or Right [Line Items]
Warrant liability | shares		1,035,196
Series A Preferred Stock
Class of Warrant or Right [Line Items]
Fair value of preferred stock | $ / shares	$ 12.00		$ 4.44