Fair Value of Financial Instruments - Valuation Assumptions for Warrant Liabilities (Details) - Significant Unobservable Inputs (Level 3) - Valuation technique, option pricing model	Sep. 30, 2021 $ / shares	Sep. 30, 2020 $ / shares
Common stock price
Key Inputs and Assumptions, Valuation Techniques
Warrant liability, measurement input	22.61	17.80
Risk free interest rate
Key Inputs and Assumptions, Valuation Techniques
Warrant liability, measurement input	0.0005	0.0013
Expected life
Key Inputs and Assumptions, Valuation Techniques
Warrant liability, expected life	6 months 21 days	1 year 6 months 21 days
Expected volatility
Key Inputs and Assumptions, Valuation Techniques
Warrant liability, measurement input	0.344	0.753
Dividend yield
Key Inputs and Assumptions, Valuation Techniques
Warrant liability, measurement input	0	0

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

Value of input used to measure outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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