Note 5 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Non-impaired gross loans		$ 703,577	$ 656,758
Real Estate Construction Portfolio Segment[Member]
Non-impaired gross loans		37,845	31,812
Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans		174,004	165,698
Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans		349,206	333,898
Commercial Non Real Estate Segment [Member]
Non-impaired gross loans		45,520	39,289
Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans		36,225	34,618
Pass [Member]
Non-impaired gross loans		701,387	651,706
Pass [Member] | States Political Subdivisions [Member]
Non-impaired gross loans		60,777	51,443
Special Mention [Member]
Non-impaired gross loans	[1]	1,455	3,361
Special Mention [Member] | States Political Subdivisions [Member]
Non-impaired gross loans	[1]	0	0
Classified Excluding Impaired [Member]
Non-impaired gross loans	[1]	735	1,691
Classified Excluding Impaired [Member] | States Political Subdivisions [Member]
Non-impaired gross loans	[1]	0	0
Construction, 1-4 Family Residential [Member] | Pass [Member] | Real Estate Construction Portfolio Segment[Member]
Non-impaired gross loans		9,264	10,396	[1]
Construction, 1-4 Family Residential [Member] | Special Mention [Member] | Real Estate Construction Portfolio Segment[Member]
Non-impaired gross loans	[1]	0
Construction, 1-4 Family Residential [Member] | Classified Excluding Impaired [Member] | Real Estate Construction Portfolio Segment[Member]
Non-impaired gross loans	[1]	0	0
Construction, Other [Member] | Pass [Member] | Real Estate Construction Portfolio Segment[Member]
Non-impaired gross loans		28,560	21,416
Construction, Other [Member] | Special Mention [Member] | Real Estate Construction Portfolio Segment[Member]
Non-impaired gross loans	[1]	21	0
Construction, Other [Member] | Classified Excluding Impaired [Member] | Real Estate Construction Portfolio Segment[Member]
Non-impaired gross loans	[1]	0	0
Equity Lines [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans		16,026	16,673
Equity Lines [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	38	39
Equity Lines [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]		0
Closed End First Liens [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans		92,253	85,975
Closed End First Liens [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	994	2,400
Closed End First Liens [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	582	355
Closed End Junior Liens [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans		3,954	4,483
Closed End Junior Liens [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]		29
Closed End Junior Liens [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]		12
Investor Owned Residential Real Estate [Member] | Pass [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans		60,157	55,410
Investor Owned Residential Real Estate [Member] | Special Mention [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]		66
Investor Owned Residential Real Estate [Member] | Classified Excluding Impaired [Member] | Consumer Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]		256
Multifamily Real Estate [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans		98,582	95,894
Multifamily Real Estate [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]		127
Multifamily Real Estate [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]		0
Commercial Real Estate, Owner Occupied [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans		123,225	130,256
Commercial Real Estate, Owner Occupied [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	211	246
Commercial Real Estate, Owner Occupied [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	32	763
Commercial Real Estate Other [Member] | Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans		127,156	106,612
Commercial Real Estate Other [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]
Commercial Real Estate Other [Member] | Classified Excluding Impaired [Member] | Commercial Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]
Commercial and Industrial [Member] | Pass [Member] | Commercial Non Real Estate Segment [Member]
Non-impaired gross loans		45,420	38,904
Commercial and Industrial [Member] | Special Mention [Member] | Commercial Non Real Estate Segment [Member]
Non-impaired gross loans	[1]	54	220
Commercial and Industrial [Member] | Classified Excluding Impaired [Member] | Commercial Non Real Estate Segment [Member]
Non-impaired gross loans	[1]	46	165
Credit Card Receivable [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans		5,724	5,493
Credit Card Receivable [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	0	0
Credit Card Receivable [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	0	0
Automobile Loan [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans		18,598	16,059
Automobile Loan [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	133	218
Automobile Loan [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	71	116
Other Consumer Loans [Member] | Pass [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans		11,691	12,692
Other Consumer Loans [Member] | Special Mention [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	4	16
Other Consumer Loans [Member] | Classified Excluding Impaired [Member] | Consumer Non Real Estate Portfolio Segment [Member]
Non-impaired gross loans	[1]	$ 4	$ 24

[1] Excludes impaired, if any.