Note 4 - Loans, Allowance for Loan Losses and Other Real Estate Owned - Credit Risk Profile by Internally Assigned Grade (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Loans	$ 1,200,192	$ 1,287,982
Pass [Member]
Loans	1,169,135	1,251,369
Substandard [Member]
Loans	30,760	35,842
Doubtful [Member]
Loans	105	1
Unlikely to be Collected Financing Receivable [Member]
Loans	192	770
Commercial Portfolio Segment [Member]
Loans	288,499	335,996
Commercial Portfolio Segment [Member] | Pass [Member]
Loans	276,492	324,185
Commercial Portfolio Segment [Member] | Substandard [Member]
Loans	12,007	11,811
Commercial Portfolio Segment [Member] | Doubtful [Member]
Loans	0	0
Commercial Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Commercial Real Estate Portfolio Segment [Member]
Loans	552,294	568,584
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Loans	536,256	548,853
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Loans	16,038	19,731
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member]
Loans	0
Commercial Real Estate Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Construction Portfolio Segment [Member]
Loans	3,254	5,649
Construction Portfolio Segment [Member] | Pass [Member]
Loans	3,254	5,649
Construction Portfolio Segment [Member] | Substandard [Member]
Loans		0
Construction Portfolio Segment [Member] | Doubtful [Member]
Loans	0	0
Construction Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Residential Portfolio Segment [Member]
Loans	54,030	65,183
Residential Portfolio Segment [Member] | Pass [Member]
Loans	52,960	62,253
Residential Portfolio Segment [Member] | Substandard [Member]
Loans	1,070	2,930
Residential Portfolio Segment [Member] | Doubtful [Member]
Loans	0	0
Residential Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Consumer Portfolio Segment [Member]
Loans	302,115	312,570
Consumer Portfolio Segment [Member] | Pass [Member]
Loans	300,173	310,429
Consumer Portfolio Segment [Member] | Substandard [Member]
Loans	1,645	1,370
Consumer Portfolio Segment [Member] | Doubtful [Member]
Loans	105	1
Consumer Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	$ 192	$ 770