Note 15 - Share-based Compensation - Stock Options Outstanding (Details)	12 Months Ended
Sep. 30, 2023 $ / shares shares
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding \| shares	2,904,882
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term	5 years 3 months
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 3.19
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable \| shares	842,667
Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price	$ 3.51
Range One [Member]
Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	1.51
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 2.68
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding \| shares	217,517
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term	3 years 2 months 19 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 2.12
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable \| shares	129,157
Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price	$ 1.74
Range Two [Member]
Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	2.69
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 2.69
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding \| shares	1,100,000
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term	6 years 7 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 2.69
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable \| shares	0
Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price	$ 0
Range Three [Member]
Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	3.09
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 3.39
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding \| shares	759,138
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term	5 years 6 months 21 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 3.29
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable \| shares	191,825
Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price	$ 3.39
Range Four [Member]
Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit	3.4
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 8.03
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding \| shares	828,227
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term	4 years 5 months 23 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 4.05
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable \| shares	521,685
Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price	$ 4

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
-Publisher FASB
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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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