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Income Taxes - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016
Income Tax Disclosure [Abstract] |  |
Valuation allowance against deferred tax assets | 100.00% |
Gross federal net operating loss carry forwards |  | $ 260.7
Gross federal estimated net operating loss carry forwards | $ 24.5 |
Gross state net operating loss carry forwards |  | $ 398.3
Gross state estimated net operating loss carry forwards | $ 24.2 |

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- Definition Percentage of valuation allowance. + References No definition available. + Details
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- Definition State estimated net operating Loss carry forward. + References No definition available. + Details
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