Note 8 - Loans and Related Allowance for Loan and Lease Losses - Loans by Credit Quality (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Loans	$ 943,674	$ 923,213
Commercial And Industrial [Member]
Loans	101,975	101,346
Real Estate Construction Porfolio Segment [Member]
Loans	45,647	47,017
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans	320,858	318,157
Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	457,050	437,947
Consumer Portfolio Segment [Member]
Loans	18,144	18,746
Pass [Member]
Loans	919,047	897,759
Pass [Member] \| Commercial And Industrial [Member]
Loans	95,486	95,621
Pass [Member] \| Real Estate Construction Porfolio Segment [Member]
Loans	44,289	46,995
Pass [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans	315,277	312,176
Pass [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	446,026	424,225
Pass [Member] \| Consumer Portfolio Segment [Member]
Loans	17,969	18,742
Special Mention [Member]
Loans	11,018	11,829
Special Mention [Member] \| Commercial And Industrial [Member]
Loans	3,095	1,942
Special Mention [Member] \| Real Estate Construction Porfolio Segment [Member]
Loans	1,358
Special Mention [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans	706	723
Special Mention [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	5,859	9,164
Substandard [Member]
Loans	13,609	13,625
Substandard [Member] \| Commercial And Industrial [Member]
Loans	3,394	3,783
Substandard [Member] \| Real Estate Construction Porfolio Segment [Member]
Loans		22
Substandard [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans	4,875	5,258
Substandard [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	5,165	4,558
Substandard [Member] \| Consumer Portfolio Segment [Member]
Loans	175	$ 4
Doubtful [Member]
Loans
Doubtful [Member] \| Commercial And Industrial [Member]
Loans
Doubtful [Member] \| Real Estate Construction Porfolio Segment [Member]
Loans
Doubtful [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans
Doubtful [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans