Note 4 - Loans and Allowance for Loan Losses - Recorded Investments in Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Principal loan balance	$ 608,925	$ 563,517	$ 546,959
Deferred loan origination fees and costs, net	1,180	1,213	1,200
Financing Receivable, amortized cost	610,105	566,548	549,696
Principal loan balance	608,925	563,517	546,959
Accrued interest receivable		1,818	1,537
Net deferred loan origination fees and costs	1,180	1,213	1,200
Recorded investment in loans	610,105	566,548	549,696
Individually evaluated for impairment		1,935	1,973
Collectively evaluated for impairment		564,327	547,429
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		286	294
Recorded investment in loans		286	294
Commercial Portfolio Segment [Member]
Principal loan balance		60,817	54,760
Deferred loan origination fees and costs, net		(11)	(12)
Financing Receivable, amortized cost		60,976	54,877
Principal loan balance		60,817	54,760
Accrued interest receivable		170	129
Net deferred loan origination fees and costs		(11)	(12)
Recorded investment in loans		60,976	54,877
Individually evaluated for impairment		195	147
Collectively evaluated for impairment		60,781	54,730
Commercial Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		0	0
Recorded investment in loans		0	0
Real Estate Loan [Member] | Real Estate Mortgage Portfolio Segment [Member]
Principal loan balance		155,334	153,659
Deferred loan origination fees and costs, net		111	107
Financing Receivable, amortized cost		155,938	154,219
Principal loan balance		155,334	153,659
Accrued interest receivable		493	453
Net deferred loan origination fees and costs		111	107
Recorded investment in loans		155,938	154,219
Individually evaluated for impairment		854	894
Collectively evaluated for impairment		154,798	153,036
Real Estate Loan [Member] | Real Estate Mortgage Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		286	289
Recorded investment in loans		286	289
Land Loan [Member] | Real Estate Mortgage Portfolio Segment [Member]
Principal loan balance		21,860	22,377
Deferred loan origination fees and costs, net		14	14
Financing Receivable, amortized cost		21,997	22,489
Principal loan balance		21,860	22,377
Accrued interest receivable		123	98
Net deferred loan origination fees and costs		14	14
Recorded investment in loans		21,997	22,489
Individually evaluated for impairment		51	51
Collectively evaluated for impairment		21,946	22,438
Land Loan [Member] | Real Estate Mortgage Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		0	0
Recorded investment in loans		0	0
Construction Loans [Member] | Real Estate Mortgage Portfolio Segment [Member]
Principal loan balance		42,271	32,196
Deferred loan origination fees and costs, net		(12)	(9)
Financing Receivable, amortized cost		42,364	32,253
Principal loan balance		42,271	32,196
Accrued interest receivable		105	66
Net deferred loan origination fees and costs		(12)	(9)
Recorded investment in loans		42,364	32,253
Individually evaluated for impairment		0	0
Collectively evaluated for impairment		42,364	32,253
Construction Loans [Member] | Real Estate Mortgage Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		0	0
Recorded investment in loans		0	0
Commercial Real Estate Loan [Member] | Real Estate Mortgage Portfolio Segment [Member]
Principal loan balance		161,425	161,296
Deferred loan origination fees and costs, net		(93)	(92)
Financing Receivable, amortized cost		161,675	161,503
Principal loan balance		161,425	161,296
Accrued interest receivable		343	299
Net deferred loan origination fees and costs		(93)	(92)
Recorded investment in loans		161,675	161,503
Individually evaluated for impairment		463	566
Collectively evaluated for impairment		161,212	160,932
Commercial Real Estate Loan [Member] | Real Estate Mortgage Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		0	5
Recorded investment in loans		0	5
Commercial Real Estate Loan [Member] | Commercial Real Estate Portfolio Segment [Member]
Principal loan balance	171,151
Deferred loan origination fees and costs, net	(114)
Financing Receivable, amortized cost	171,037
Principal loan balance	171,151
Net deferred loan origination fees and costs	(114)
Recorded investment in loans	171,037
Home Equity and Second Mortgage [Member] | Consumer Portfolio Segment [Member]
Principal loan balance	59,815	57,781	58,596
Deferred loan origination fees and costs, net	1,237	1,204	1,192
Financing Receivable, amortized cost	61,052	59,333	60,060
Principal loan balance	59,815	57,781	58,596
Accrued interest receivable		348	272
Net deferred loan origination fees and costs	1,237	1,204	1,192
Recorded investment in loans	61,052	59,333	60,060
Individually evaluated for impairment		372	315
Collectively evaluated for impairment		58,961	59,745
Home Equity and Second Mortgage [Member] | Consumer Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		0	0
Recorded investment in loans		0	0
Other Consumer Loan [Member] | Consumer Portfolio Segment [Member]
Principal loan balance	56,659	64,029	64,075
Deferred loan origination fees and costs, net	0	0	0
Financing Receivable, amortized cost	56,659	64,265	64,295
Principal loan balance	56,659	64,029	64,075
Accrued interest receivable		236	220
Net deferred loan origination fees and costs	0	0	0
Recorded investment in loans	56,659	64,265	64,295
Individually evaluated for impairment		0	0
Collectively evaluated for impairment		64,265	64,295
Other Consumer Loan [Member] | Consumer Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		0	0
Recorded investment in loans		$ 0	$ 0
One-to-four Family Loan [Member] | Residential Portfolio Segment [Member]
Principal loan balance	132,662
Deferred loan origination fees and costs, net	124
Financing Receivable, amortized cost	132,786
Principal loan balance	132,662
Net deferred loan origination fees and costs	124
Recorded investment in loans	132,786
Multifamily [Member] | Residential Portfolio Segment [Member]
Principal loan balance	40,168
Deferred loan origination fees and costs, net	(16)
Financing Receivable, amortized cost	40,152
Principal loan balance	40,168
Net deferred loan origination fees and costs	(16)
Recorded investment in loans	40,152
One-to-four Family Residential Construction [Member] | Construction [Member]
Principal loan balance	15,936
Deferred loan origination fees and costs, net	0
Financing Receivable, amortized cost	15,936
Principal loan balance	15,936
Net deferred loan origination fees and costs	0
Recorded investment in loans	15,936
Other Construction, Development and Land [Member] | Construction [Member]
Principal loan balance	66,629
Deferred loan origination fees and costs, net	(40)
Financing Receivable, amortized cost	66,589
Principal loan balance	66,629
Net deferred loan origination fees and costs	(40)
Recorded investment in loans	66,589
Commercial Business [Member] | Commercial Portfolio Segment [Member]
Principal loan balance	65,905
Deferred loan origination fees and costs, net	(11)
Financing Receivable, amortized cost	65,894
Principal loan balance	65,905
Net deferred loan origination fees and costs	(11)
Recorded investment in loans	$ 65,894