| Warrants - Additional Information (Details) - USD ($) | 3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
| Mar. 31, 2021 | Mar. 31, 2020 | Mar. 31, 2021 | Mar. 31, 2020 | Sep. 30, 2020 | |
| Class Of Warrant Or Right [Line Items] | |||||
| Fair value adjustment of warrants | $ 0 | $ 368,000 | |||
| Series B Convertible Preferred Stock Warrants | |||||
| Class Of Warrant Or Right [Line Items] | |||||
| Warrants additional extended expiration period | 2 years | ||||
| Fair value adjustment of warrants | $ 0 | $ 102,000 | $ 0 | $ 368,000 | |
| Series B Convertible Preferred Stock Warrants | Series B Convertible Preferred Stock | |||||
| Class Of Warrant Or Right [Line Items] | |||||
| Number of warrants outstanding | 118,029 | ||||
| Warrants exercise price | $ 20.80 | ||||
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- Definition Class of warrant or right expiration period. No definition available. 
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- Definition Class of warrant or right outstanding and exercisable. No definition available. 
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- Definition Weighted average exercise price of warrants outstanding and exercisable. No definition available. 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition Amount of expense (income) related to adjustment to fair value of warrant liability. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Details 
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