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Income Taxes - Tax carryforward and reconciliation of unrecognized tax benefit (Details) - USD ($) | 12 Months Ended
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Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2019
Tax credit carryforward |  |  |
Change in valuation allowance | $ 2,022,000 | $ 451,000 |
Valuation allowance | 1,449,204 | 3,471,164 | $ 3,922,620
Reconciliation of beginning and ending balances of total amounts of gross unrecognized tax benefits |  |  |
Balance at beginning of year | 615,000 | 546,000 | 540,000
Unrecognized tax benefits related to prior years |  | 39,000 |
Unrecognized tax benefits related to current year | 7,000 | 37,000 | 6,000
Decrease in unrecognized tax benefits due to the lapse of applicable statute of limitations | (32,000) | (7,000) |
Balance at end of year | 590,000 | 615,000 | 546,000
Unrecognized tax benefits , if recognized, would impact effective tax rate | 590,000 | 615,000 | $ 546,000
Unrecognized tax benefits against accrued interest | 0 |  |
Accrual recorded for penalties | 0 |  |
Adjustments resulting from IRS examination | 0 |  |
R&D | Federal |  |  |
Tax credit carryforward |  |  |
Tax Credit carryforwards | $ 1,327,000 | $ 1,589,000 |

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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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319 + Details
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- Definition The amount of the additional liability or refund received or expected based on a final settlement with a taxing authority. + References No definition available. + Details
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319 + Details
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- Definition Amount of statutory penalties accrued for a tax position claimed or expected to be claimed by the entity, in its tax return. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32718-109319 + Details
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