Note 4 - Fair Value of Financial Instruments - Fair Value by Hierarchy (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Total assets	$ 14,921	$ 894
Contingent consideration liabilities		175
Total liabilities		175
Fair Value, Inputs, Level 1 [Member]
Total assets	0	0
Contingent consideration liabilities		0
Total liabilities		0
Fair Value, Inputs, Level 2 [Member]
Total assets	14,921	894
Contingent consideration liabilities		0
Total liabilities		0
Fair Value, Inputs, Level 3 [Member]
Total assets	0	0
Contingent consideration liabilities		175
Total liabilities		175
Corporate Debt Securities [Member]
Short term investment	11,295	894
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Short term investment	0	0
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Short term investment	11,295	894
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Short term investment	0	$ 0
US Treasury and Government Short-Term Debt Securities [Member]
Short term investment	3,626
US Treasury and Government Short-Term Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Short term investment	$ 3,626

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
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Amount of liability recognized arising from contingent consideration in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479581/805-30-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
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-Section 25
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479668/805-30-25-6

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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-Topic 805
-Publisher FASB
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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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Fair value of financial and nonfinancial obligations.

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