Note 3 - Loans and Allowance for Loan Losses - Aging of Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Past Due	$ 5,321	$ 6,911
Current	468,338	432,614
Loans	473,984	439,855
Financial Asset Acquired with Credit Deterioration [Member]
Loans	325	330
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	3,866	4,732
Current	139,236	132,005
Loans	143,385	137,019
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	283	282
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	239	438
Current	21,818	22,306
Loans	22,057	22,744
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	156
Current	35,584	25,442
Loans	35,740	25,442
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due		450
Current	116,748	107,174
Loans	116,790	107,672
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans	42	48
Commercial Portfolio Segment [Member]
Past Due	111	522
Current	38,613	35,895
Loans	38,724	36,417
Commercial Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	568	226
Current	53,115	52,777
Loans	53,683	53,003
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Past Due	381	543
Current	63,224	57,015
Loans	63,605	57,558
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Loans
Financial Asset, 30 to 59 Days Past Due [Member]
Past Due	3,105	4,373
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	1,984	2,617
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	150	247
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due	156
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due		450
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	16	377
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	448	191
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	351	491
Financial Asset, 60 to 89 Days Past Due [Member]
Past Due	906	1,015
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	721	926
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	36	39
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Past Due
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	37
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	83
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	29	50
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Past Due	1,310	1,523
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Past Due	1,161	1,189
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Past Due	53	152
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Past Due
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
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Past Due	58	145
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Past Due	37	35
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	$ 1	$ 2