Note 4 - Loans Receivable and Related Allowance for Loan Losses - Classes of Loan Portfolio by Aging Categories (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Loans	$ 805,200	$ 790,403
Nonaccrual	3,553	2,654
Financial Asset, Not Past Due [Member]
Loans	797,345	783,741
Nonaccrual	2,703	1,590
Financial Asset, 30 to 59 Days Past Due [Member]
Loans	3,061	2,333
Nonaccrual	77	10
Financial Asset, 60 to 89 Days Past Due [Member]
Loans	511	990
Nonaccrual	6	69
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	730	685
Nonaccrual	767	985
Residential Portfolio Segment [Member]
Loans	273,724	273,823
Nonaccrual	730	810
Residential Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Loans	270,100	270,221
Nonaccrual	190	196
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	2,190	1,913
Nonaccrual	68	0
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	254	588
Nonaccrual	0	69
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	450	291
Nonaccrual	472	545
Home Equity Loans and Lines of Credit [Member]
Loans	73,731	75,810
Nonaccrual	122	242
Home Equity Loans and Lines of Credit [Member] | Financial Asset, Not Past Due [Member]
Loans	73,030	74,853
Nonaccrual	4	4
Home Equity Loans and Lines of Credit [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	299	230
Nonaccrual	0	0
Home Equity Loans and Lines of Credit [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	206	325
Nonaccrual	0	0
Home Equity Loans and Lines of Credit [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	74	160
Nonaccrual	118	238
Commercial Real Estate Portfolio Segment [Member]
Loans	347,447	326,341
Nonaccrual	2,601	1,250
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Loans	344,447	325,018
Nonaccrual	2,420	1,052
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	358	73
Nonaccrual	9	10
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	41	0
Nonaccrual	6	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0	0
Nonaccrual	166	188
Commercial Portfolio Segment [Member]
Loans	61,381	65,877
Nonaccrual	89	338
Commercial Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Loans	61,030	65,305
Nonaccrual	89	338
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	56	0
Nonaccrual	0	0
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	0	0
Nonaccrual	0	0
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	206	234
Nonaccrual	0	0
Consumer Portfolio Segment [Member]
Loans	48,917	48,552
Nonaccrual	11	14
Consumer Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Loans	48,738	48,344
Nonaccrual	0	0
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans	158	117
Nonaccrual	0	0
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans	10	77
Nonaccrual	0	0
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0	0
Nonaccrual	$ 11	$ 14