Note 5 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans, collectively evaluated for impairment	$ 656,758	$ 639,373
Real Estate Construction Portfolio Segment[Member]
Loans, collectively evaluated for impairment	31,812	36,075
Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	165,698	156,841
Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	333,898	328,675
Commercial Non Real Estate Segment [Member]
Loans, collectively evaluated for impairment	39,289	38,783
Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	34,618	33,525
Pass [Member]
Loans, collectively evaluated for impairment	651,706	622,802
Pass [Member] | States Political Subdivisions [Member]
Loans, collectively evaluated for impairment	51,443	45,474
Special Mention [Member]
Loans, collectively evaluated for impairment	3,361	13,519
Special Mention [Member] | States Political Subdivisions [Member]
Loans, collectively evaluated for impairment	0	0
Classified Excluding Impaired [Member]
Loans, collectively evaluated for impairment	1,691	3,052
Classified Excluding Impaired [Member] | States Political Subdivisions [Member]
Loans, collectively evaluated for impairment	0	0
Construction, 1-4 Family Residential [Member] | Pass [Member] | Real Estate Construction Portfolio Segment[Member]
Loans, collectively evaluated for impairment	10,396	11,635
Construction, 1-4 Family Residential [Member] | Special Mention [Member] | Real Estate Construction Portfolio Segment[Member]
Loans, collectively evaluated for impairment	0	3,648
Construction, 1-4 Family Residential [Member] | Classified Excluding Impaired [Member] | Real Estate Construction Portfolio Segment[Member]
Loans, collectively evaluated for impairment	0	0
Construction, Other [Member] | Pass [Member] | Real Estate Construction Portfolio Segment[Member]
Loans, collectively evaluated for impairment	21,416	20,972
Construction, Other [Member] | Special Mention [Member] | Real Estate Construction Portfolio Segment[Member]
Loans, collectively evaluated for impairment	0	0
Construction, Other [Member] | Classified Excluding Impaired [Member] | Real Estate Construction Portfolio Segment[Member]
Loans, collectively evaluated for impairment	0	0
Equity Lines [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	16,673	17,034
Equity Lines [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	39	82
Equity Lines [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	0	0
Closed End First Liens [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	85,975	83,658
Closed End First Liens [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	2,400	1,267
Closed End First Liens [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	355	580
Closed End Junior Liens [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	4,483	4,861
Closed End Junior Liens [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	29	15
Closed End Junior Liens [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	12	151
Investor Owned Residential Real Estate [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	55,410	48,277
Investor Owned Residential Real Estate [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	66	333
Investor Owned Residential Real Estate [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	256	583
Multifamily Real Estate [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	95,894	99,002
Multifamily Real Estate [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	127	1,733
Multifamily Real Estate [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment		0
Commercial Real Estate, Owner Occupied [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	130,256	120,170
Commercial Real Estate, Owner Occupied [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	246	1,188
Commercial Real Estate, Owner Occupied [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	763	1,425
Commercial Real Estate Other [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	106,612	103,534
Commercial Real Estate Other [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	0	1,543
Commercial Real Estate Other [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	0	80
Commercial and Industrial [Member] | Pass [Member] | Commercial Non Real Estate Segment [Member]
Loans, collectively evaluated for impairment	38,904	35,521
Commercial and Industrial [Member] | Special Mention [Member] | Commercial Non Real Estate Segment [Member]
Loans, collectively evaluated for impairment	220	3,229
Commercial and Industrial [Member] | Classified Excluding Impaired [Member] | Commercial Non Real Estate Segment [Member]
Loans, collectively evaluated for impairment	165	33
Credit Card Receivable [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	5,493	5,978
Credit Card Receivable [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	0	0
Credit Card Receivable [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	0	0
Automobile Loan [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	16,059	14,457
Automobile Loan [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	218	25
Automobile Loan [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	116	192
Other Consumer Loans [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	12,692	12,229
Other Consumer Loans [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	16	636
Other Consumer Loans [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Loans, collectively evaluated for impairment	$ 24	$ 8