Related Party Transactions - Remy Trafelet (Details) - Remy W. Trafelet - USD ($)  | 
12 Months Ended | ||
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Feb. 11, 2019  | 
Sep. 30, 2021  | 
Sep. 30, 2020  | 
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| Related Party Transaction [Line Items] | |||
| Period of consulting services provided (up to) | 24 months | ||
| Payments for services and covenants | $ 400,000 | $ 800,000 | |
| Expense under shared services agreement | $ 800,000 | ||
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- Definition Related Party Transaction, Period Of Consulting Services Provided No definition available. 
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- Definition Amount of transactions with related party during the financial reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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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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- Details 
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