Note 4 - Allowance for Loan Losses - Loans by Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans	$ 471,462	$ 444,195
Pass [Member]
Loans	466,100	428,225
Special Mention [Member]
Loans	3,054	12,964
Substandard [Member]
Loans	1,137	2,005
Substandard Nonaccrual [Member]
Loans	1,084	804
Doubtful [Member]
Loans	87	197
Construction Loan Portfolio Segment [Member] | Residential [Member]
Loans	17,232	15,221
Construction Loan Portfolio Segment [Member] | Residential [Member] | Pass [Member]
Loans	17,232	15,221
Construction Loan Portfolio Segment [Member] | Residential [Member] | Special Mention [Member]
Loans
Construction Loan Portfolio Segment [Member] | Residential [Member] | Substandard [Member]
Loans
Construction Loan Portfolio Segment [Member] | Residential [Member] | Substandard Nonaccrual [Member]
Loans
Construction Loan Portfolio Segment [Member] | Residential [Member] | Doubtful [Member]
Loans
Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member]
Loans	28,903	35,601
Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member] | Pass [Member]
Loans	28,860	31,433
Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member] | Special Mention [Member]
Loans		3,987
Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member] | Substandard [Member]
Loans
Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member] | Substandard Nonaccrual [Member]
Loans	43	181
Construction Loan Portfolio Segment [Member] | Land Acquisition Development And Commercial [Member] | Doubtful [Member]
Loans
Real Estate Portfolio Segment [Member] | Residential [Member]
Loans	143,385	121,649
Real Estate Portfolio Segment [Member] | Residential [Member] | Pass [Member]
Loans	142,473	120,575
Real Estate Portfolio Segment [Member] | Residential [Member] | Special Mention [Member]
Loans	408	342
Real Estate Portfolio Segment [Member] | Residential [Member] | Substandard [Member]
Loans	182	559
Real Estate Portfolio Segment [Member] | Residential [Member] | Substandard Nonaccrual [Member]
Loans	235
Real Estate Portfolio Segment [Member] | Residential [Member] | Doubtful [Member]
Loans	87	173
Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans	184,989	173,999
Real Estate Portfolio Segment [Member] | Commercial [Member] | Pass [Member]
Loans	181,842	165,760
Real Estate Portfolio Segment [Member] | Commercial [Member] | Special Mention [Member]
Loans	2,122	7,386
Real Estate Portfolio Segment [Member] | Commercial [Member] | Substandard [Member]
Loans	562	644
Real Estate Portfolio Segment [Member] | Commercial [Member] | Substandard Nonaccrual [Member]
Loans	463	209
Real Estate Portfolio Segment [Member] | Commercial [Member] | Doubtful [Member]
Loans
Commercial Industrial and Agricultural Portfolio Segment [Member]
Loans	60,265	61,197
Commercial Industrial and Agricultural Portfolio Segment [Member] | Pass [Member]
Loans	59,262	59,042
Commercial Industrial and Agricultural Portfolio Segment [Member] | Special Mention [Member]
Loans	477	1,249
Commercial Industrial and Agricultural Portfolio Segment [Member] | Substandard [Member]
Loans	393	503
Commercial Industrial and Agricultural Portfolio Segment [Member] | Substandard Nonaccrual [Member]
Loans	133	379
Commercial Industrial and Agricultural Portfolio Segment [Member] | Doubtful [Member]
Loans		24
Equity Lines Portfolio Segment [Member]
Loans	28,969	28,835
Equity Lines Portfolio Segment [Member] | Pass [Member]
Loans	28,712	28,536
Equity Lines Portfolio Segment [Member] | Special Mention [Member]
Loans	47
Equity Lines Portfolio Segment [Member] | Substandard [Member]
Loans		299
Equity Lines Portfolio Segment [Member] | Substandard Nonaccrual [Member]
Loans	210
Equity Lines Portfolio Segment [Member] | Doubtful [Member]
Loans
Consumer Portfolio Segment [Member]
Loans	7,719	7,693
Consumer Portfolio Segment [Member] | Pass [Member]
Loans	7,719	7,658
Consumer Portfolio Segment [Member] | Special Mention [Member]
Loans
Consumer Portfolio Segment [Member] | Substandard [Member]
Loans
Consumer Portfolio Segment [Member] | Substandard Nonaccrual [Member]
Loans		35
Consumer Portfolio Segment [Member] | Doubtful [Member]
Loans