Note 4 - Loans and Allowance for Loan Losses - Recorded Investments in Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Principal loan balance	$ 571,682	$ 563,517	$ 511,039
Deferred loan origination fees and costs, net	1,217	1,213	1,156
Financing Receivable, amortized cost	572,899	566,548	513,668
Principal loan balance	571,682	563,517	511,039
Accrued interest receivable		1,818	1,473
Net deferred loan origination fees and costs	1,217	1,213	1,156
Recorded investment in loans	572,899	566,548	513,668
Individually evaluated for impairment		1,935	1,979
Collectively evaluated for impairment		564,327	511,412
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		286	277
Recorded investment in loans		286	277
Commercial Portfolio Segment [Member]
Principal loan balance		60,817	58,031
Deferred loan origination fees and costs, net		(11)	(21)
Financing Receivable, amortized cost		60,976	58,173
Principal loan balance		60,817	58,031
Accrued interest receivable		170	163
Net deferred loan origination fees and costs		(11)	(21)
Recorded investment in loans		60,976	58,173
Individually evaluated for impairment		195	167
Collectively evaluated for impairment		60,781	58,006
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	137,762
Deferred loan origination fees and costs, net		111	99
Financing Receivable, amortized cost		155,938	138,329
Principal loan balance		155,334	137,762
Accrued interest receivable		493	468
Net deferred loan origination fees and costs		111	99
Recorded investment in loans		155,938	138,329
Individually evaluated for impairment		854	824
Collectively evaluated for impairment		154,798	137,236
Real Estate Loan [Member] | Real Estate Mortgage Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		286	269
Recorded investment in loans		286	269
Land Loan [Member] | Real Estate Mortgage Portfolio Segment [Member]
Principal loan balance		21,860	19,489
Deferred loan origination fees and costs, net		14	13
Financing Receivable, amortized cost		21,997	19,605
Principal loan balance		21,860	19,489
Accrued interest receivable		123	103
Net deferred loan origination fees and costs		14	13
Recorded investment in loans		21,997	19,605
Individually evaluated for impairment		51	102
Collectively evaluated for impairment		21,946	19,503
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	31,702
Deferred loan origination fees and costs, net		(12)	(11)
Financing Receivable, amortized cost		42,364	31,765
Principal loan balance		42,271	31,702
Accrued interest receivable		105	74
Net deferred loan origination fees and costs		(12)	(11)
Recorded investment in loans		42,364	31,765
Individually evaluated for impairment		0	0
Collectively evaluated for impairment		42,364	31,765
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	148,492
Deferred loan origination fees and costs, net		(93)	(72)
Financing Receivable, amortized cost		161,675	148,720
Principal loan balance		161,425	148,492
Accrued interest receivable		343	300
Net deferred loan origination fees and costs		(93)	(72)
Recorded investment in loans		161,675	148,720
Individually evaluated for impairment		463	599
Collectively evaluated for impairment		161,212	148,113
Commercial Real Estate Loan [Member] | Real Estate Mortgage Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, amortized cost		0	8
Recorded investment in loans		0	8
Commercial Real Estate Loan [Member] | Commercial Real Estate Portfolio Segment [Member]
Principal loan balance	161,968
Deferred loan origination fees and costs, net	(91)
Financing Receivable, amortized cost	161,877
Principal loan balance	161,968
Net deferred loan origination fees and costs	(91)
Recorded investment in loans	161,877
Home Equity and Second Mortgage [Member] | Consumer Portfolio Segment [Member]
Principal loan balance	57,130	57,781	55,893
Deferred loan origination fees and costs, net	1,210	1,204	1,148
Financing Receivable, amortized cost	58,340	59,333	57,207
Principal loan balance	57,130	57,781	55,893
Accrued interest receivable		348	166
Net deferred loan origination fees and costs	1,210	1,204	1,148
Recorded investment in loans	58,340	59,333	57,207
Individually evaluated for impairment		372	287
Collectively evaluated for impairment		58,961	56,920
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	54,053	64,029	59,670
Deferred loan origination fees and costs, net	0	0	0
Financing Receivable, amortized cost	54,053	64,265	59,869
Principal loan balance	54,053	64,029	59,670
Accrued interest receivable		236	199
Net deferred loan origination fees and costs	0	0	0
Recorded investment in loans	54,053	64,265	59,869
Individually evaluated for impairment		0	0
Collectively evaluated for impairment		64,265	59,869
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	122,675
Deferred loan origination fees and costs, net	127
Financing Receivable, amortized cost	122,802
Principal loan balance	122,675
Net deferred loan origination fees and costs	127
Recorded investment in loans	122,802
Multifamily [Member] | Residential Portfolio Segment [Member]
Principal loan balance	39,656
Deferred loan origination fees and costs, net	(14)
Financing Receivable, amortized cost	39,642
Principal loan balance	39,656
Net deferred loan origination fees and costs	(14)
Recorded investment in loans	39,642
One-to-four Family Residential Construction [Member] | Construction [Member]
Principal loan balance	19,071
Deferred loan origination fees and costs, net	0
Financing Receivable, amortized cost	19,071
Principal loan balance	19,071
Net deferred loan origination fees and costs	0
Recorded investment in loans	19,071
Other Construction, Development and Land [Member] | Construction [Member]
Principal loan balance	49,901
Deferred loan origination fees and costs, net	(3)
Financing Receivable, amortized cost	49,898
Principal loan balance	49,901
Net deferred loan origination fees and costs	(3)
Recorded investment in loans	49,898
Commercial Business [Member] | Commercial Portfolio Segment [Member]
Principal loan balance	67,228
Deferred loan origination fees and costs, net	(12)
Financing Receivable, amortized cost	67,216
Principal loan balance	67,228
Net deferred loan origination fees and costs	(12)
Recorded investment in loans	$ 67,216