Note 4 - Loans - Internal Risk Rating by Loan Class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Gross loans	$ 900,420	$ 879,835
Commercial Portfolio Segment [Member]
Gross loans	137,870	142,405
Commercial Real Estate Portfolio Segment [Member]
Gross loans	613,201	585,593
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans	14,723	15,902
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	405,192	377,668
Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	193,286	192,023
Residential Portfolio Segment [Member]
Gross loans	101,192	101,912
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	40,425	41,188
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	30,247	30,377
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	30,520	30,347
Consumer Portfolio Segment [Member]
Gross loans	48,157	49,925
Pass [Member]
Gross loans	833,252	809,332
Pass [Member] | Commercial Portfolio Segment [Member]
Gross loans	108,907	117,087
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans	13,583	14,762
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	396,829	364,230
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	173,616	171,005
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	34,222	34,923
Pass [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	29,276	28,981
Pass [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	28,699	28,457
Pass [Member] | Consumer Portfolio Segment [Member]
Gross loans	48,120	49,887
Watch [Member]
Gross loans	44,226	48,863
Watch [Member] | Commercial Portfolio Segment [Member]
Gross loans	24,023	22,213
Watch [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans
Watch [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	5,452	9,160
Watch [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	12,467	15,198
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	784	791
Watch [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	1,500	1,501
Watch [Member] | Consumer Portfolio Segment [Member]
Gross loans
Special Mention [Member]
Gross loans	10,238	8,052
Special Mention [Member] | Commercial Portfolio Segment [Member]
Gross loans	2,627	40
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	1,543	2,900
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	6,066	3,907
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	2
Substandard [Member]
Gross loans	12,704	13,588
Substandard [Member] | Commercial Portfolio Segment [Member]
Gross loans	2,313	3,065
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Gross loans	1,140
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Gross loans	1,368	1,378
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Owner Occupied Loan [Member]
Gross loans	1,137	1,913
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Individual Tax Identification Number Loan [Member]
Gross loans	6,203	6,265
Substandard [Member] | Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Gross loans	187	605
Substandard [Member] | Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Gross loans	321	326
Substandard [Member] | Consumer Portfolio Segment [Member]
Gross loans	35	36
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