Note 4 - Loans Receivable and Related Allowance for Loan Losses - Nonaccrual Loans by Aging Category (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Nonaccrual	$ 3,310	$ 2,654
Financial Asset, Not Past Due [Member]
Nonaccrual	2,482	1,590
Financial Asset, 30 to 59 Days Past Due [Member]
Nonaccrual	8	10
Financial Asset, 60 to 89 Days Past Due [Member]
Nonaccrual	68	69
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Nonaccrual	752	985
Residential Portfolio Segment [Member]
Nonaccrual	697	810
Residential Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Nonaccrual	184	196
Residential Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Nonaccrual	0	0
Residential Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Nonaccrual	68	69
Residential Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Nonaccrual	445	545
Home Equity Loans and Lines of Credit [Member]
Nonaccrual	241	242
Home Equity Loans and Lines of Credit [Member] | Financial Asset, Not Past Due [Member]
Nonaccrual	4	4
Home Equity Loans and Lines of Credit [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Nonaccrual	0	0
Home Equity Loans and Lines of Credit [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Nonaccrual	0	0
Home Equity Loans and Lines of Credit [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Nonaccrual	237	238
Commercial Real Estate Portfolio Segment [Member]
Nonaccrual	2,277	1,250
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Nonaccrual	2,209	1,052
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Nonaccrual	8	10
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Nonaccrual	0	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Nonaccrual	60	188
Commercial Portfolio Segment [Member]
Nonaccrual	85	338
Commercial Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Nonaccrual	85	338
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Nonaccrual	0	0
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Nonaccrual	0	0
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Nonaccrual	0	0
Consumer Portfolio Segment [Member]
Nonaccrual	10	14
Consumer Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Nonaccrual	0	0
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Nonaccrual	0	0
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Nonaccrual	0	0
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Nonaccrual	$ 10	$ 14