Note 4 - Fair Value of Financial Instruments - Fair Value by Hierarchy (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Business Combination, Contingent Consideration, Liability, Current	$ 0	$ 175
Fair Value, Recurring [Member]
Total assets		894
Business Combination, Contingent Consideration, Liability, Current		175
Total liabilities		175
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Total assets		0
Business Combination, Contingent Consideration, Liability, Current		0
Total liabilities		0
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Total assets		894
Business Combination, Contingent Consideration, Liability, Current		0
Total liabilities		0
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Total assets		0
Business Combination, Contingent Consideration, Liability, Current		175
Total liabilities		175
Corporate Debt Securities [Member] \| Fair Value, Recurring [Member]
Corporate bonds		894
Corporate Debt Securities [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Corporate bonds		0
Corporate Debt Securities [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Corporate bonds		894
Corporate Debt Securities [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Corporate bonds		$ 0

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
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479668/805-30-25-6

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 35
-Paragraph 1
-Subparagraph b
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479613/805-30-35-1

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- Definition

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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- Definition

Fair value of financial and nonfinancial obligations.

+ References

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