| Income Taxes - Additional Information (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
|---|---|---|---|
| Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2017 | |
| Tax Credit Carryforward [Line Items] | |||
| Valuation allowance | $ 729 | ||
| Income tax rate | 21.00% | 24.30% | 35.00% | 
| Federal | |||
| Tax Credit Carryforward [Line Items] | |||
| Net operating loss carryforward | $ 21,300 | ||
| Operating loss carryforward expiration date | Dec. 31, 2030 | ||
| State | |||
| Tax Credit Carryforward [Line Items] | |||
| Net operating loss carryforward | $ 11,300 | ||
| Operating loss carryforward expiration date | Dec. 31, 2019 | ||
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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Expiration date of each operating loss carryforward included in operating loss carryforward, in CCYY-MM-DD format. 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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