Note 4 - Loans, Allowance for Credit Losses and Other Real Estate Owned - Risk Category of Loans by Class (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Loans	$ 741,579,000		$ 741,579,000		$ 820,300,000
Nonaccrual	2,347,000		2,347,000		201,000
Loans, Writeoff	2,471,000	$ 1,658,000	5,149,000	$ 5,202,000
Financial Asset, Not Past Due [Member]
Loans	735,750,000		735,750,000		813,339,000
Financial Asset, 30 to 59 Days Past Due [Member]
Loans	2,463,000		2,463,000		5,314,000
Financial Asset, 60 to 89 Days Past Due [Member]
Loans	722,000		722,000		912,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	297,000		297,000		534,000
Pass [Member]
Loans	728,110,000		728,110,000		789,715,000
Substandard [Member]
Loans	11,597,000		11,597,000		29,867,000
Doubtful [Member]
Loans	1,492,000		1,492,000		192,000
Unlikely to be Collected Financing Receivable [Member]
Loans	380,000		380,000		526,000
Commercial Portfolio Segment [Member]
Originated prior	21,580,000		21,580,000		19,018,000
Originated four years before	4,952,000		4,952,000		8,542,000
Originated three years before	9,250,000		9,250,000		21,374,000
Originated two years before	7,368,000		7,368,000		12,388,000
Originated one years before	17,112,000		17,112,000		14,776,000
Originated current year	29,365,000		29,365,000		19,399,000
Total Term Loans	89,627,000		89,627,000		95,497,000
Financing Receivable Revolving	24,213,000		24,213,000		31,779,000
Loans	113,840,000		113,840,000		127,276,000
Nonaccrual	1,429,000		1,429,000		10,000
Originated prior, writeoff	0		0		59,000
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	1,559,000		1,559,000		0
Originated three years before, writeoff	0		0		0
Originated two years before, writeoff	0		5,000		0
Originated one years before, writeoff	0		0		0
Originated current year, writeoff	0		0		0
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	1,559,000		1,564,000		59,000
Financing Receivable Revolving, Writeoff	0		33,000		224,000
Loans, Writeoff	1,559,000	109,000	1,597,000	137,000	283,000
Commercial Portfolio Segment [Member] \| Financial Asset, Not Past Due [Member]
Loans	112,164,000		112,164,000		126,538,000
Commercial Portfolio Segment [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Loans	96,000		96,000		700,000
Commercial Portfolio Segment [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Loans	151,000		151,000		28,000
Commercial Portfolio Segment [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0		0		0
Commercial Portfolio Segment [Member] \| Pass [Member]
Originated prior	21,365,000		21,365,000		18,752,000
Originated four years before	4,952,000		4,952,000		8,542,000
Originated three years before	9,250,000		9,250,000		18,539,000
Originated two years before	7,368,000		7,368,000		12,388,000
Originated one years before	17,112,000		17,112,000		14,776,000
Originated current year	28,122,000		28,122,000		19,399,000
Total Term Loans	88,169,000		88,169,000		92,396,000
Financing Receivable Revolving	23,099,000		23,099,000		30,562,000
Loans	111,268,000		111,268,000		122,958,000
Commercial Portfolio Segment [Member] \| Substandard [Member]
Originated prior	215,000		215,000		266,000
Originated four years before	0		0		0
Originated three years before	0		0		2,835,000
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	515,000		515,000		0
Total Term Loans	730,000		730,000		3,101,000
Financing Receivable Revolving	414,000		414,000		1,217,000
Loans	1,144,000		1,144,000		4,318,000
Commercial Portfolio Segment [Member] \| Doubtful [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	728,000		728,000		0
Total Term Loans	728,000		728,000		0
Financing Receivable Revolving	700,000		700,000		0
Loans	1,428,000		1,428,000		0
Commercial Portfolio Segment [Member] \| Unlikely to be Collected Financing Receivable [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		0
Loans	0		0		0
Commercial Real Estate Portfolio Segment [Member]
Originated prior	228,383,000		228,383,000		214,569,000
Originated four years before	56,562,000		56,562,000		66,353,000
Originated three years before	47,828,000		47,828,000		63,697,000
Originated two years before	41,358,000		41,358,000		49,117,000
Originated one years before	69,894,000		69,894,000		43,091,000
Originated current year	45,359,000		45,359,000		71,073,000
Total Term Loans	489,384,000		489,384,000		507,900,000
Financing Receivable Revolving	0		0		0
Loans	489,384,000		489,384,000		507,900,000
Nonaccrual	918,000		918,000		191,000
Originated prior, writeoff	0		191,000		0
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	0		0		0
Originated three years before, writeoff	0		0		0
Originated two years before, writeoff	0		0		0
Originated one years before, writeoff	0		0		0
Originated current year, writeoff	0		0		0
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	0		191,000		0
Financing Receivable Revolving, Writeoff	0		0		0
Loans, Writeoff	(0)	(0)	191,000	(0)	0
Commercial Real Estate Portfolio Segment [Member] \| Financial Asset, Not Past Due [Member]
Loans	487,884,000		487,884,000		506,588,000
Commercial Real Estate Portfolio Segment [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Loans	582,000		582,000		1,121,000
Commercial Real Estate Portfolio Segment [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Loans	0		0		0
Commercial Real Estate Portfolio Segment [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0		0		0
Commercial Real Estate Portfolio Segment [Member] \| Pass [Member]
Originated prior	220,763,000		220,763,000		197,160,000
Originated four years before	56,562,000		56,562,000		65,384,000
Originated three years before	46,909,000		46,909,000		63,697,000
Originated two years before	41,358,000		41,358,000		49,117,000
Originated one years before	69,894,000		69,894,000		43,091,000
Originated current year	45,189,000		45,189,000		71,073,000
Total Term Loans	480,675,000		480,675,000		489,522,000
Financing Receivable Revolving	0		0		0
Loans	480,675,000		480,675,000		489,522,000
Commercial Real Estate Portfolio Segment [Member] \| Substandard [Member]
Originated prior	7,620,000		7,620,000		17,409,000
Originated four years before	0		0		969,000
Originated three years before	919,000		919,000		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	170,000		170,000		0
Total Term Loans	8,709,000		8,709,000		18,378,000
Financing Receivable Revolving	0		0		0
Loans	8,709,000		8,709,000		18,378,000
Commercial Real Estate Portfolio Segment [Member] \| Doubtful [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		0
Loans	0		0		0
Commercial Real Estate Portfolio Segment [Member] \| Unlikely to be Collected Financing Receivable [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		0
Loans	0		0		0
Residential Portfolio Segment [Member]
Originated prior	7,517,000		7,517,000		8,274,000
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	7,517,000		7,517,000		8,274,000
Financing Receivable Revolving	0		0		0
Loans	7,517,000		7,517,000		8,274,000
Nonaccrual	0		0		0
Originated prior, writeoff	0		0		0
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	0		0		0
Originated three years before, writeoff	0		0		0
Originated two years before, writeoff	0		0		0
Originated one years before, writeoff	0		0		0
Originated current year, writeoff	0		0		0
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	0		0		0
Financing Receivable Revolving, Writeoff	0		0		0
Loans, Writeoff	(0)	(0)	(0)	(0)	0
Residential Portfolio Segment [Member] \| Financial Asset, Not Past Due [Member]
Loans	7,517,000		7,517,000		8,274,000
Residential Portfolio Segment [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Loans	0		0		0
Residential Portfolio Segment [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Loans	0		0		0
Residential Portfolio Segment [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0		0		0
Residential Portfolio Segment [Member] \| Pass [Member]
Originated prior	7,312,000		7,312,000		7,984,000
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	7,312,000		7,312,000		7,984,000
Financing Receivable Revolving	0		0		0
Loans	7,312,000		7,312,000		7,984,000
Residential Portfolio Segment [Member] \| Substandard [Member]
Originated prior	205,000		205,000		290,000
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	205,000		205,000		290,000
Financing Receivable Revolving	0		0		0
Loans	205,000		205,000		290,000
Residential Portfolio Segment [Member] \| Doubtful [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		0
Loans	0		0		0
Residential Portfolio Segment [Member] \| Unlikely to be Collected Financing Receivable [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		0
Loans	0		0		0
Construction Portfolio Segment [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		5,064,000
Loans	0		0		5,064,000
Nonaccrual	0		0		0
Originated prior, writeoff	0		0		0
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	0		0		0
Originated three years before, writeoff	0		0		0
Originated two years before, writeoff	0		0		0
Originated one years before, writeoff	0		0		0
Originated current year, writeoff	0		0		0
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	0		0		0
Financing Receivable Revolving, Writeoff	0		0		0
Loans, Writeoff	(0)	(0)	(0)	(0)	0
Construction Portfolio Segment [Member] \| Financial Asset, Not Past Due [Member]
Loans	0		0		5,064,000
Construction Portfolio Segment [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Loans	0		0		0
Construction Portfolio Segment [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Loans	0		0		0
Construction Portfolio Segment [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0		0		0
Construction Portfolio Segment [Member] \| Pass [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		0
Loans	0		0		0
Construction Portfolio Segment [Member] \| Substandard [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		5,064,000
Loans	0		0		5,064,000
Construction Portfolio Segment [Member] \| Doubtful [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		0
Loans	0		0		0
Construction Portfolio Segment [Member] \| Unlikely to be Collected Financing Receivable [Member]
Originated prior	0		0		0
Originated four years before	0		0		0
Originated three years before	0		0		0
Originated two years before	0		0		0
Originated one years before	0		0		0
Originated current year	0		0		0
Total Term Loans	0		0		0
Financing Receivable Revolving	0		0		0
Loans	0		0		0
Consumer Portfolio Segment [Member]
Originated prior	8,530,000		8,530,000		6,274,000
Originated four years before	22,096,000		22,096,000		12,739,000
Originated three years before	35,592,000		35,592,000		33,870,000
Originated two years before	20,104,000		20,104,000		50,542,000
Originated one years before	19,061,000		19,061,000		27,430,000
Originated current year	11,298,000		11,298,000		24,905,000
Total Term Loans	116,681,000		116,681,000		155,760,000
Financing Receivable Revolving	14,157,000		14,157,000		16,026,000
Loans	130,838,000		130,838,000		171,786,000
Nonaccrual	0		0		0
Originated prior, writeoff	86,000		216,000		246,000
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	68,000		595,000		388,000
Originated three years before, writeoff	334,000		1,228,000		2,376,000
Originated two years before, writeoff	199,000		565,000		1,843,000
Originated one years before, writeoff	161,000		612,000		913,000
Originated current year, writeoff	5,000		5,000		162,000
Financing Receivable, before Allowance for Credit Loss and Revolving Loans, Writeoff	853,000		3,221,000		5,928,000
Financing Receivable Revolving, Writeoff	59,000		140,000		463,000
Loans, Writeoff	912,000	$ 1,549,000	3,361,000	$ 5,065,000	6,391,000
Consumer Portfolio Segment [Member] \| Term Loan Originated Prior [Member]
Nonaccrual	0		0		0
Consumer Portfolio Segment [Member] \| Term Loans Originated Four Years Prior [Member]
Nonaccrual	0		0		0
Consumer Portfolio Segment [Member] \| Term Loans Originated Three Years Prior [Member]
Nonaccrual	0		0		0
Consumer Portfolio Segment [Member] \| Term Loans Originated Two Years Prior [Member]
Nonaccrual	0		0		0
Consumer Portfolio Segment [Member] \| Term Loans Originated One Year Prior [Member]
Nonaccrual	0		0		0
Consumer Portfolio Segment [Member] \| Term Loans Originated Current Year [Member]
Nonaccrual	0		0		0
Consumer Portfolio Segment [Member] \| Total Term Loans [Member]
Nonaccrual	0		0		0
Consumer Portfolio Segment [Member] \| Revolving Loans Amortized Cost Basis [Member]
Nonaccrual	0		0		0
Consumer Portfolio Segment [Member] \| Financial Asset, Not Past Due [Member]
Originated prior	8,266,000		8,266,000		6,068,000
Originated four years before	21,397,000		21,397,000		12,464,000
Originated three years before	34,756,000		34,756,000		32,608,000
Originated two years before	19,757,000		19,757,000		48,694,000
Originated one years before	18,764,000		18,764,000		26,805,000
Originated current year	11,198,000		11,198,000		24,522,000
Total Term Loans	114,138,000		114,138,000		151,161,000
Financing Receivable Revolving	14,047,000		14,047,000		15,714,000
Loans	128,185,000		128,185,000		166,875,000
Consumer Portfolio Segment [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Originated prior	202,000		202,000		173,000
Originated four years before	534,000		534,000		201,000
Originated three years before	553,000		553,000		949,000
Originated two years before	247,000		247,000		1,392,000
Originated one years before	105,000		105,000		385,000
Originated current year	100,000		100,000		263,000
Total Term Loans	1,741,000		1,741,000		3,363,000
Financing Receivable Revolving	44,000		44,000		130,000
Loans	1,785,000		1,785,000		3,493,000
Consumer Portfolio Segment [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Originated prior	29,000		29,000		33,000
Originated four years before	90,000		90,000		36,000
Originated three years before	181,000		181,000		184,000
Originated two years before	100,000		100,000		256,000
Originated one years before	156,000		156,000		91,000
Originated current year	0		0		120,000
Total Term Loans	556,000		556,000		720,000
Financing Receivable Revolving	15,000		15,000		164,000
Loans	571,000		571,000		884,000
Consumer Portfolio Segment [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Originated prior	33,000		33,000		0
Originated four years before	75,000		75,000		38,000
Originated three years before	102,000		102,000		129,000
Originated two years before	0		0		200,000
Originated one years before	36,000		36,000		149,000
Originated current year	0		0		0
Total Term Loans	246,000		246,000		516,000
Financing Receivable Revolving	51,000		51,000		18,000
Loans	297,000		297,000		534,000
Consumer Portfolio Segment [Member] \| Pass [Member]
Loans	128,855,000		128,855,000		169,251,000
Consumer Portfolio Segment [Member] \| Substandard [Member]
Loans	1,539,000		1,539,000		1,817,000
Consumer Portfolio Segment [Member] \| Doubtful [Member]
Loans	64,000		64,000		192,000
Consumer Portfolio Segment [Member] \| Unlikely to be Collected Financing Receivable [Member]
Loans	$ 380,000		$ 380,000		$ 526,000

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ 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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 1: http://www.xbrl.org/2003/role/exampleRef
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