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Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Valuation allowance against deferred tax assets		100.00%
Gross federal net operating loss carry forwards		$ 314.8
Gross state net operating loss carry forwards		$ 211.5
U.S. federal statutory rate	35.00%	21.00%	21.00%
Revaluation provision to income tax expense			$ 37.0

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- Definition

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Percentage of valuation allowance.

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- Definition

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- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
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Amount of income tax expense (benefit) for remeasurement of deferred tax from change in tax rate pursuant to Tax Cuts and Jobs Act.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

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