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Note 2 - Securities - Changes in the Allowance for Credit Loss on Held to Maturity Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Balance, June 30, 2025	$ 98	$ 109	$ 95	$ 107	$ 107
Provision for credit losses, HTM	(15)	(5)	(12)	(3)	(12)
Charge-offs of securities, HTM	0	0	0	0	0
Recoveries, HTM	0	0	0	0	0
Balance, HTM	83	104	83	104	95
US Treasury Securities [Member]
Balance, June 30, 2025	0	0	(0)	0	0
Provision for credit losses, HTM	0	0	0	0	0
Charge-offs of securities, HTM	0	0	0	0	0
Recoveries, HTM	0	0	0	0	0
Balance, HTM	(0)	0	(0)	0	(0)
US Agency and Mortgage-backed Securities [Member]
Balance, June 30, 2025	0	0	(0)	0	0
Provision for credit losses, HTM	0	0	0	0	0
Charge-offs of securities, HTM	0	0	0	0	0
Recoveries, HTM	0	0	0	0	0
Balance, HTM	(0)	0	(0)	0	(0)
US States and Political Subdivisions Debt Securities [Member]
Balance, June 30, 2025	0	1	(0)	0	0
Provision for credit losses, HTM	0	0	0	1	0
Charge-offs of securities, HTM	0	0	0	0	0
Recoveries, HTM	0	0	0	0	0
Balance, HTM	(0)	1	(0)	1	(0)
Corporate Debt Securities [Member]
Balance, June 30, 2025	98	108	95	107	107
Provision for credit losses, HTM	(15)	(5)	(12)	(4)	(12)
Charge-offs of securities, HTM	0	0	0	0	0
Recoveries, HTM	0	0	0	0	0
Balance, HTM	$ 83	$ 103	$ 83	$ 103	$ 95

X

- Definition

Amount, excluding accrued interest, of allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-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

+ Details

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Balance Type:	credit
Period Type:	instant

X

- Definition

Amount, excluding accrued interest, 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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X

- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity) from writeoff.

+ 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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X

- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) 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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-22

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