Note 4 - Loans - Performing and Nonperforming Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Gross loans	$ 927,480	$ 879,835
Commercial Portfolio Segment [Member]
Gross loans	132,091	142,405
Commercial Real Estate Portfolio Segment [Member]
Gross loans	647,350	585,593
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans	20,496	15,902
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	431,246	377,668
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	195,608	192,023
Residential Portfolio Segment [Member]
Gross loans	100,539	101,912
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	38,353	41,188
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	33,473	30,377
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	28,713	30,347
Consumer Portfolio Segment [Member]
Gross loans	47,500	49,925
Performing Financial Instruments [Member]
Gross loans	923,763	874,036
Performing Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Gross loans	131,192	140,802
Performing Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans	20,496	15,902
Performing Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	431,246	377,668
Performing Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	195,608	191,423
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	35,782	38,279
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	33,294	29,771
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	28,669	30,302
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member]
Gross loans	47,476	49,889
Nonperforming Financial Instruments [Member]
Gross loans	3,717	5,799
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member]
Gross loans	899	1,603
Nonperforming Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans
Nonperforming Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans
Nonperforming Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans		600
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	2,571	2,909
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	179	606
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	44	45
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member]
Gross loans	$ 24	$ 36