Note 4 - Loans - Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Loans	$ 834,347	$ 835,207
Commercial Loans [Member]
Loans	548,439	520,847
Accruing Loans [Member]
Loans	284,051	313,278
Nonaccrual Loans [Member]
Loans	1,857	1,082
Subtotal, Other Loans [Member]
Loans	285,908	314,360
Pass [Member] | Commercial Loans [Member]
Loans	525,109	499,208
Special Mention [Member] | Commercial Loans [Member]
Loans	9,343	8,007
Substandard [Member] | Commercial Loans [Member]
Loans	13,987	13,632
Doubtful [Member] | Commercial Loans [Member]
Loans	0	0
Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans	0	0
Residential Portfolio Segment [Member]
Loans	165,850	164,833
Residential Portfolio Segment [Member] | Commercial Loans [Member]
Loans	32,813	34,018
Residential Portfolio Segment [Member] | Accruing Loans [Member]
Loans	131,809	130,132
Residential Portfolio Segment [Member] | Nonaccrual Loans [Member]
Loans	1,228	683
Residential Portfolio Segment [Member] | Subtotal, Other Loans [Member]
Loans	133,037	130,815
Residential Portfolio Segment [Member] | Pass [Member] | Commercial Loans [Member]
Loans	32,373	33,573
Residential Portfolio Segment [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	214	291
Residential Portfolio Segment [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	226	154
Residential Portfolio Segment [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans	0	0
Residential Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans	0	0
Commercial Real Estate Portfolio Segment [Member]
Loans	279,591	262,778
Commercial Real Estate Portfolio Segment [Member] | Commercial Loans [Member]
Loans	279,591	262,778
Commercial Real Estate Portfolio Segment [Member] | Accruing Loans [Member]
Loans	0	0
Commercial Real Estate Portfolio Segment [Member] | Nonaccrual Loans [Member]
Loans	0	0
Commercial Real Estate Portfolio Segment [Member] | Subtotal, Other Loans [Member]
Loans	0	0
Commercial Real Estate Portfolio Segment [Member] | Pass [Member] | Commercial Loans [Member]
Loans	261,053	250,674
Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	6,655	1,858
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	11,883	10,246
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans	0	0
Commercial Real Estate Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans	0	0
Construction, Land Acquisition and Development [Member]
Loans	39,371	20,813
Construction, Land Acquisition and Development [Member] | Commercial Loans [Member]
Loans	37,543	18,461
Construction, Land Acquisition and Development [Member] | Accruing Loans [Member]
Loans	1,828	2,352
Construction, Land Acquisition and Development [Member] | Nonaccrual Loans [Member]
Loans	0	0
Construction, Land Acquisition and Development [Member] | Subtotal, Other Loans [Member]
Loans	1,828	2,352
Construction, Land Acquisition and Development [Member] | Pass [Member] | Commercial Loans [Member]
Loans	37,543	17,704
Construction, Land Acquisition and Development [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	0	0
Construction, Land Acquisition and Development [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	0	757
Construction, Land Acquisition and Development [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans	0	0
Construction, Land Acquisition and Development [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans	0	0
Commercial and Industrial [Member]
Loans	163,464	150,962
Commercial and Industrial [Member] | Commercial Loans [Member]
Loans	157,970	144,529
Commercial and Industrial [Member] | Accruing Loans [Member]
Loans	5,494	6,421
Commercial and Industrial [Member] | Nonaccrual Loans [Member]
Loans	0	12
Commercial and Industrial [Member] | Subtotal, Other Loans [Member]
Loans	5,494	6,433
Commercial and Industrial [Member] | Pass [Member] | Commercial Loans [Member]
Loans	153,618	137,888
Commercial and Industrial [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	2,474	4,193
Commercial and Industrial [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	1,878	2,448
Commercial and Industrial [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans	0	0
Commercial and Industrial [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans	0	0
Consumer Portfolio Segment [Member]
Loans	148,435	176,784
Consumer Portfolio Segment [Member] | Commercial Loans [Member]
Loans	2,907	2,024
Consumer Portfolio Segment [Member] | Accruing Loans [Member]
Loans	144,899	174,373
Consumer Portfolio Segment [Member] | Nonaccrual Loans [Member]
Loans	629	387
Consumer Portfolio Segment [Member] | Subtotal, Other Loans [Member]
Loans	145,528	174,760
Consumer Portfolio Segment [Member] | Pass [Member] | Commercial Loans [Member]
Loans	2,907	2,024
Consumer Portfolio Segment [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans	0	0
Consumer Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans	0	0
State and Political Subdivisions [Member]
Loans	37,636	59,037
State and Political Subdivisions [Member] | Commercial Loans [Member]
Loans	37,615	59,037
State and Political Subdivisions [Member] | Accruing Loans [Member]
Loans	21	0
State and Political Subdivisions [Member] | Nonaccrual Loans [Member]
Loans	0	0
State and Political Subdivisions [Member] | Subtotal, Other Loans [Member]
Loans	21	0
State and Political Subdivisions [Member] | Pass [Member] | Commercial Loans [Member]
Loans	37,615	57,345
State and Political Subdivisions [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	0	1,665
State and Political Subdivisions [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	0	27
State and Political Subdivisions [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans	0	0
State and Political Subdivisions [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans	$ 0	$ 0