Note 3 - Investment Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss	$ 647,387	$ 639,532
Unrealized Gains, Available-for-sale	757	3,125
Unrealized Losses, Available-for-sale	(29,213)	(25,414)
Investment securities – available-for-sale, at estimated fair value, net of allowance for credit losses of $0; amortized cost of $647,387 at June 30, 2026 and $639,532 at December 31, 2025	618,931	617,243
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest	0	0
US Treasury Securities [Member]
Unrealized Gains, Available-for-sale	56	420
Unrealized Losses, Available-for-sale	(818)	(442)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest	0	0
US Government Corporations and Agencies Securities [Member]
Unrealized Gains, Available-for-sale	132	462
Unrealized Losses, Available-for-sale	(2,222)	(1,949)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest	0	0
US States and Political Subdivisions Debt Securities [Member]
Unrealized Gains, Available-for-sale	266	448
Unrealized Losses, Available-for-sale	(3,113)	(3,241)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Collateralized Mortgage Obligations [Member]
Unrealized Gains, Available-for-sale	26	155
Unrealized Losses, Available-for-sale	(12,568)	(11,235)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Unrealized Gains, Available-for-sale	277	1,640
Unrealized Losses, Available-for-sale	(10,492)	(8,547)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest	0	0
Reported Value Measurement [Member]
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss	647,387	639,532
Reported Value Measurement [Member] \| US Treasury Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss	88,411	87,578
Reported Value Measurement [Member] \| US Government Corporations and Agencies Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss	91,691	86,831
Reported Value Measurement [Member] \| US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss	76,755	77,796
Reported Value Measurement [Member] \| Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss	108,602	103,364
Reported Value Measurement [Member] \| Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss	281,928	283,963
Estimate of Fair Value Measurement [Member]
Investment securities – available-for-sale, at estimated fair value, net of allowance for credit losses of $0; amortized cost of $647,387 at June 30, 2026 and $639,532 at December 31, 2025	618,931	617,243
Estimate of Fair Value Measurement [Member] \| US Treasury Securities [Member]
Investment securities – available-for-sale, at estimated fair value, net of allowance for credit losses of $0; amortized cost of $647,387 at June 30, 2026 and $639,532 at December 31, 2025	87,649	87,556
Estimate of Fair Value Measurement [Member] \| US Government Corporations and Agencies Securities [Member]
Investment securities – available-for-sale, at estimated fair value, net of allowance for credit losses of $0; amortized cost of $647,387 at June 30, 2026 and $639,532 at December 31, 2025	89,601	85,344
Estimate of Fair Value Measurement [Member] \| US States and Political Subdivisions Debt Securities [Member]
Investment securities – available-for-sale, at estimated fair value, net of allowance for credit losses of $0; amortized cost of $647,387 at June 30, 2026 and $639,532 at December 31, 2025	73,908	75,003
Estimate of Fair Value Measurement [Member] \| Collateralized Mortgage Obligations [Member]
Investment securities – available-for-sale, at estimated fair value, net of allowance for credit losses of $0; amortized cost of $647,387 at June 30, 2026 and $639,532 at December 31, 2025	96,060	92,284
Estimate of Fair Value Measurement [Member] \| Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Investment securities – available-for-sale, at estimated fair value, net of allowance for credit losses of $0; amortized cost of $647,387 at June 30, 2026 and $639,532 at December 31, 2025	$ 271,713	$ 277,056

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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