Note 3 - Loans and Allowance for Loan Losses - Recorded Investment in Loans by Risk Category (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Loans	$ 473,984	$ 439,855
Pass [Member]
Loans	466,635	431,650
Special Mention [Member]
Loans	2,365	2,510
Substandard [Member]
Loans	3,085	2,569
Doubtful [Member]
Loans	1,899	3,126
Unlikely to be Collected Financing Receivable [Member]
Loans
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Loans	143,385	137,019
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Pass [Member]
Loans	140,354	133,878
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Special Mention [Member]
Loans	47	133
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Substandard [Member]
Loans	1,317	1,168
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Doubtful [Member]
Loans	1,667	1,840
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Loans	22,057	22,744
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Pass [Member]
Loans	21,524	22,458
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Special Mention [Member]
Loans	330	65
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Substandard [Member]
Loans	114	69
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Doubtful [Member]
Loans	89	152
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Loans	35,740	25,442
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Pass [Member]
Loans	35,390	24,921
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Special Mention [Member]
Loans	350
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Substandard [Member]
Loans
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Doubtful [Member]
Loans		521
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Loans	116,790	107,672
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Pass [Member]
Loans	114,510	104,843
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Special Mention [Member]
Loans	1,050	1,520
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Substandard [Member]
Loans	1,230	938
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Doubtful [Member]
Loans		371
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans
Commercial Portfolio Segment [Member]
Loans	38,724	36,417
Commercial Portfolio Segment [Member] | Pass [Member]
Loans	37,853	35,162
Commercial Portfolio Segment [Member] | Special Mention [Member]
Loans	523	763
Commercial Portfolio Segment [Member] | Substandard [Member]
Loans	290	285
Commercial Portfolio Segment [Member] | Doubtful [Member]
Loans	58	207
Commercial Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Loans	53,683	53,003
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Pass [Member]
Loans	53,512	52,859
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Special Mention [Member]
Loans
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Substandard [Member]
Loans	134	109
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Doubtful [Member]
Loans	37	35
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Loans	63,605	57,558
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member] | Pass [Member]
Loans	63,492	57,529
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member] | Special Mention [Member]
Loans	65	29
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member] | Substandard [Member]
Loans
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member] | Doubtful [Member]
Loans	48
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans