Note 3 - Securities Held to Maturity - Schedule of Held to Maturity Allowance for Credit Loss (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Balance	$ 108,000	$ 0	$ 0	$ 0
Provision for credit losses	0	0	108,000	0
Securities losses	0	0	0	0
Recoveries	0	0	0	0
Balance	108,000	0	108,000	0
Cumulative Effect, Period of Adoption, Adjustment [Member] \| Accounting Standards Update 2016-13 [Member]
Balance		0		0
US Government Agencies Debt Securities [Member]
Balance	0	0	0	0
Provision for credit losses	0	0	0	0
Securities losses	0	0	0	0
Recoveries	0	0	0	0
Balance	0	0	0	0
US Government Agencies Debt Securities [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member] \| Accounting Standards Update 2016-13 [Member]
Balance		0		0
Corporate Debt Securities [Member]
Balance	108,000	0	0	0
Provision for credit losses	0	0	108,000	0
Securities losses	0	0	0	0
Recoveries	0	0	0	0
Balance	108,000	0	108,000	0
Corporate Debt Securities [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member] \| Accounting Standards Update 2016-13 [Member]
Balance		0		0
US States and Political Subdivisions Debt Securities [Member]
Balance	0	0	0	0
Provision for credit losses	0	0	0	0
Securities losses	0	0	0	0
Recoveries	0	0	0	0
Balance	0	0	0	0
US States and Political Subdivisions Debt Securities [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member] \| Accounting Standards Update 2016-13 [Member]
Balance		0		0
Residential Mortgage-Backed Securities [Member]
Balance	0	0	0	0
Provision for credit losses	0	0	0	0
Securities losses	0	0	0	0
Recoveries	0	0	0	0
Balance	0	0	0	0
Residential Mortgage-Backed Securities [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member] \| Accounting Standards Update 2016-13 [Member]
Balance		0		0
Commercial Mortgage-Backed Securities [Member]
Balance	0	0	0	0
Provision for credit losses	0	0	0	0
Securities losses	0	0	0	0
Recoveries	0	0	0	0
Balance	$ 0	0	$ 0	0
Commercial Mortgage-Backed Securities [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member] \| Accounting Standards Update 2016-13 [Member]
Balance		$ 0		$ 0

Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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- Definition

Amount of increase in allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity), from recovery.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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- Definition

Amount of writeoff of investment in debt security, measured at amortized cost (held-to-maturity), charged against allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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- Definition

Amount of expense (reversal of expense) for expected credit loss on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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