Note 3 - Loans and Allowance for Loan Losses - Recorded Investment in Nonperforming Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Total Nonperforming Loans	$ 6,791	$ 6,911
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Total Nonperforming Loans	5,042	4,732
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Total Nonperforming Loans	423	438
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Total Nonperforming Loans
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Total Nonperforming Loans	346	450
Commercial Portfolio Segment [Member]
Total Nonperforming Loans	261	522
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Total Nonperforming Loans	316	226
Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Total Nonperforming Loans	403	543
Nonperforming Financial Instruments [Member]
Nonaccrual Loans	2,482	3,055
Loans 90+ Days Past Due Still Accruing	81	2
Total Nonperforming Loans	2,563	3,057
Nonperforming Financial Instruments [Member] | Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Nonaccrual Loans	1,713	1,769
Loans 90+ Days Past Due Still Accruing	76
Total Nonperforming Loans	1,789	1,769
Nonperforming Financial Instruments [Member] | Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Nonaccrual Loans	192	152
Loans 90+ Days Past Due Still Accruing
Total Nonperforming Loans	192	152
Nonperforming Financial Instruments [Member] | Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Nonaccrual Loans		521
Loans 90+ Days Past Due Still Accruing
Total Nonperforming Loans		521
Nonperforming Financial Instruments [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Nonaccrual Loans	351	371
Loans 90+ Days Past Due Still Accruing
Total Nonperforming Loans	351	371
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Nonaccrual Loans	198	207
Loans 90+ Days Past Due Still Accruing
Total Nonperforming Loans	198	207
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Nonaccrual Loans	28	35
Loans 90+ Days Past Due Still Accruing
Total Nonperforming Loans	28	35
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | All Other Consumer Excluding Home Equity and Second Mortgage [Member]
Nonaccrual Loans
Loans 90+ Days Past Due Still Accruing	5	2
Total Nonperforming Loans	$ 5	$ 2