Note 8 - Loans and Related Allowance for Loan and Lease Losses - Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans, current balance	$ 993,633	$ 984,245
Loans, past due	10,851	7,864
Loans	1,004,484	992,109
Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	3,876	3,583
Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due	4,830	1,296
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	2,145	2,985
Commercial And Industrial [Member]
Loans, current balance	85,157	82,770
Loans, past due	599	1,087
Loans	85,756	83,857
Commercial And Industrial [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	279	288
Commercial And Industrial [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due	73	213
Commercial And Industrial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	247	586
Real Estate Construction Porfolio Segment [Member]
Loans, current balance	54,515	56,731
Loans, past due	3,504	0
Loans	58,019	56,731
Real Estate Construction Porfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	265	0
Real Estate Construction Porfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due	3,239	0
Real Estate Construction Porfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	0	0
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Loans, current balance	335,148	331,379
Loans, past due	5,335	5,108
Loans	340,483	336,487
Real Estate Mortgage Portfolio Segment [Member] | Commercial Loans [Member]
Loans, current balance	502,895	496,597
Loans, past due	1,394	1,650
Loans	504,289	498,247
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Residential Loan [Member]
Loans, past due	2,816	2,612
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Loans [Member]
Loans, past due	499	664
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Residential Loan [Member]
Loans, past due	1,094	1,083
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Loans [Member]
Loans, past due	422
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Loan [Member]
Loans, past due	1,425	1,413
Real Estate Mortgage Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans [Member]
Loans, past due	473	986
Consumer Portfolio Segment [Member]
Loans, current balance	15,918	16,768
Loans, past due	19	19
Loans	15,937	16,787
Consumer Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Loans, past due	17	19
Consumer Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Loans, past due	2	0
Consumer Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans, past due	$ 0	$ 0