Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Provision for income taxes	$ 382	$ 292	$ 242
Expiration year	2033
Effective Income Tax Rate	21.00%	21.00%	24.00%
Impact of unrecognised tax benenfits on income tax rate if recognized	$ 200
Domestic Tax Authority [Member]
Operating loss carry forwards	448,800
Domestic Tax Authority [Member] \| Research Tax Credit Carryforward [Member]
Tax credit carry forwards	8,000
State and Local Jurisdiction [Member]
Operating loss carry forwards	278,400
State and Local Jurisdiction [Member] \| Research Tax Credit Carryforward [Member]
Tax credit carry forwards	$ 6,900

Tax credit carryforward, expiration year.

No definition available.

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- Definition

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

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- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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- Definition

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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- Definition

The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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