Note 8 - Loans and Related Allowance for Loan and Lease Losses - Classes of the Loan Portfolio Summarized by Credit Quality (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans	$ 1,004,484	$ 992,109
Commercial And Industrial [Member]
Loans	85,756	83,857
Real Estate Construction Porfolio Segment [Member]
Loans	58,019	56,731
Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans	340,483	336,487
Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	504,289	498,247
Consumer Portfolio Segment [Member]
Loans	15,937	16,787
Pass [Member]
Loans	974,363	965,166
Pass [Member] \| Commercial And Industrial [Member]
Loans	80,203	77,002
Pass [Member] \| Real Estate Construction Porfolio Segment [Member]
Loans	53,458	55,397
Pass [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans	335,486	332,475
Pass [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	489,289	483,516
Pass [Member] \| Consumer Portfolio Segment [Member]
Loans	15,927	16,776
Special Mention [Member]
Loans	11,817	13,076
Special Mention [Member] \| Commercial And Industrial [Member]
Loans	3,204	4,572
Special Mention [Member] \| Real Estate Construction Porfolio Segment [Member]
Loans	1,322	1,334
Special Mention [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans	547	553
Special Mention [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	6,744	6,617
Substandard [Member]
Loans	18,304	13,867
Substandard [Member] \| Commercial And Industrial [Member]
Loans	2,349	2,283
Substandard [Member] \| Real Estate Construction Porfolio Segment [Member]
Loans	3,239
Substandard [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Residential Loan [Member]
Loans	4,450	3,459
Substandard [Member] \| Real Estate Mortgage Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	8,256	8,114
Substandard [Member] \| Consumer Portfolio Segment [Member]
Loans	10	$ 11
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