Note 3 - Loans and Allowance for Loan Losses - Recorded Investment in Nonperforming Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Total Nonperforming Loans	$ 2,566	$ 3,872
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Total Nonperforming Loans	1,897	2,625
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Total Nonperforming Loans	282	351
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Total Nonperforming Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Total Nonperforming Loans	147	155
Commercial Portfolio Segment [Member]
Total Nonperforming Loans	13	0
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Total Nonperforming Loans	54	355
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Total Nonperforming Loans	173	386
Nonperforming Financial Instruments [Member]
Nonaccrual Loans	1,860	1,406
Loans 90+ Days Past Due Still Accruing	0	59
Total Nonperforming Loans	1,860	1,465
Nonperforming Financial Instruments [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Nonaccrual Loans	1,309	1,154
Loans 90+ Days Past Due Still Accruing	0	0
Total Nonperforming Loans	1,309	1,154
Nonperforming Financial Instruments [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Nonaccrual Loans	100	97
Loans 90+ Days Past Due Still Accruing	0	59
Total Nonperforming Loans	100	156
Nonperforming Financial Instruments [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Nonaccrual Loans	0	0
Loans 90+ Days Past Due Still Accruing	0	0
Total Nonperforming Loans	0	0
Nonperforming Financial Instruments [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Nonaccrual Loans	147	155
Loans 90+ Days Past Due Still Accruing	0	0
Total Nonperforming Loans	147	155
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Nonaccrual Loans	0	0
Loans 90+ Days Past Due Still Accruing	0	0
Total Nonperforming Loans	0	0
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Nonaccrual Loans	304	0
Loans 90+ Days Past Due Still Accruing	0	0
Total Nonperforming Loans	304	0
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Nonaccrual Loans	0	0
Loans 90+ Days Past Due Still Accruing	0	0
Total Nonperforming Loans	$ 0	$ 0