Note 3 - Loans and Allowance for Loan Losses - Aging of Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Past Due	$ 2,566	$ 3,872
Current	488,035	504,710
Loans	490,897	508,879
Financial Asset Acquired with Credit Deterioration [Member]
Loans	296	297
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	1,897	2,625
Current	123,559	128,954
Loans	125,727	131,850
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	271	271
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	282	351
Current	16,817	17,110
Loans	17,099	17,461
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	0	0
Current	28,995	25,018
Loans	28,995	25,018
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	0	0
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due	147	155
Current	133,605	135,303
Loans	133,777	135,484
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	25	26
Commercial Portfolio Segment [Member]
Past Due	13	0
Current	71,177	81,809
Loans	71,190	81,809
Commercial Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	54	355
Current	51,557	52,922
Loans	51,611	53,277
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Past Due	173	386
Current	62,325	63,594
Loans	62,498	63,980
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	0	0
Financial Asset, 30 to 59 Days Past Due [Member]
Past Due	1,646	2,295
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	1,109	1,672
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	237	130
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due	147	155
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	25	53
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Past Due	128	285
Financial Asset, 60 to 89 Days Past Due [Member]
Past Due	94	695
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	20	227
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	0	65
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	13	0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	16	302
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Past Due	45	101
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past Due	826	882
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	768	726
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	45	156
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	13	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Past Due	$ 0	$ 0