Note 5 - Loans - Internal Risk Rating by Loan Class (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gross loans	$ 879,835	$ 804,211	$ 716,639
Commercial Portfolio Segment [Member]
Gross loans	149,088	153,844	132,805
Commercial Real Estate Portfolio Segment [Member]
Gross loans	578,910	496,742	427,992
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans	15,902	36,792
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	377,668	292,615
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	185,340	167,335
Residential Portfolio Segment [Member]
Gross loans	101,912	101,944	105,969
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	41,188	45,566
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	30,377	20,425
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	30,347	35,953
Consumer Portfolio Segment [Member]
Gross loans	49,925	51,681	$ 49,873
Pass [Member]
Gross loans	809,332	743,235
Pass [Member] | Commercial Portfolio Segment [Member]
Gross loans	117,087	124,089
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans	14,762	36,782
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	364,230	284,099
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	171,005	157,064
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	34,923	38,279
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	28,981	17,696
Pass [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	28,457	33,828
Pass [Member] | Consumer Portfolio Segment [Member]
Gross loans	49,887	51,398
Watch [Member]
Gross loans	48,863	36,068
Watch [Member] | Commercial Portfolio Segment [Member]
Gross loans	28,896	21,684
Watch [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans		10
Watch [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	9,160	5,398
Watch [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	8,515	7,301
Watch [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans
Watch [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	791	815
Watch [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	1,501	858
Watch [Member] | Consumer Portfolio Segment [Member]
Gross loans		2
Special Mention [Member]
Gross loans	8,052	6,387
Special Mention [Member] | Commercial Portfolio Segment [Member]
Gross loans	40	4,570
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans	1,140
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	2,900	1,321
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	3,907	496
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans
Special Mention [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans
Special Mention [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	63
Special Mention [Member] | Consumer Portfolio Segment [Member]
Gross loans	2
Substandard [Member]
Gross loans	13,588	18,521
Substandard [Member] | Commercial Portfolio Segment [Member]
Gross loans	3,065	3,501
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	1,378	1,797
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	1,913	2,474
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	6,265	7,287
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	605	1,914
Substandard [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	326	1,267
Substandard [Member] | Consumer Portfolio Segment [Member]
Gross loans	36	281
Doubtful [Member]
Gross loans
Doubtful [Member] | Commercial Portfolio Segment [Member]
Gross loans
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans
Doubtful [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans
Doubtful [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans
Doubtful [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans
Doubtful [Member] | Consumer Portfolio Segment [Member]
Gross loans