Note 4 - Loans - Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans	$ 833,154	$ 826,356
Commercial Loans [Member]
Loans	561,878	546,961
Accruing Loans [Member]
Loans	269,514	277,413
Nonaccrual Loans [Member]
Loans	1,762	1,982
Subtotal, Other Loans [Member]
Loans	271,276	279,395
Pass [Member] | Commercial Loans [Member]
Loans	547,424	532,300
Special Mention [Member] | Commercial Loans [Member]
Loans	2,426	2,271
Substandard [Member] | Commercial Loans [Member]
Loans	12,028	12,390
Doubtful [Member] | Commercial Loans [Member]
Loans
Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans
Residential Portfolio Segment [Member]
Loans	171,764	170,723
Residential Portfolio Segment [Member] | Commercial Loans [Member]
Loans	32,168	32,703
Residential Portfolio Segment [Member] | Accruing Loans [Member]
Loans	138,475	136,709
Residential Portfolio Segment [Member] | Nonaccrual Loans [Member]
Loans	1,121	1,311
Residential Portfolio Segment [Member] | Subtotal, Other Loans [Member]
Loans	139,596	138,020
Residential Portfolio Segment [Member] | Pass [Member] | Commercial Loans [Member]
Loans	31,653	32,219
Residential Portfolio Segment [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	173	177
Residential Portfolio Segment [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	342	307
Residential Portfolio Segment [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans
Residential Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans
Commercial Real Estate Portfolio Segment [Member]
Loans	276,662	278,379
Commercial Real Estate Portfolio Segment [Member] | Commercial Loans [Member]
Loans	276,662	278,379
Commercial Real Estate Portfolio Segment [Member] | Accruing Loans [Member]
Loans
Commercial Real Estate Portfolio Segment [Member] | Nonaccrual Loans [Member]
Loans
Commercial Real Estate Portfolio Segment [Member] | Subtotal, Other Loans [Member]
Loans
Commercial Real Estate Portfolio Segment [Member] | Pass [Member] | Commercial Loans [Member]
Loans	264,693	266,112
Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	1,641	1,668
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	10,328	10,599
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans
Commercial Real Estate Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans
Construction, Land Acquisition and Development [Member]
Loans	43,929	47,484
Construction, Land Acquisition and Development [Member] | Commercial Loans [Member]
Loans	42,767	46,361
Construction, Land Acquisition and Development [Member] | Accruing Loans [Member]
Loans	1,162	1,123
Construction, Land Acquisition and Development [Member] | Nonaccrual Loans [Member]
Loans
Construction, Land Acquisition and Development [Member] | Subtotal, Other Loans [Member]
Loans	1,162	1,123
Construction, Land Acquisition and Development [Member] | Pass [Member] | Commercial Loans [Member]
Loans	42,767	46,361
Construction, Land Acquisition and Development [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans
Construction, Land Acquisition and Development [Member] | Substandard [Member] | Commercial Loans [Member]
Loans
Construction, Land Acquisition and Development [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans
Construction, Land Acquisition and Development [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans
Commercial and Industrial [Member]
Loans	161,654	147,623
Commercial and Industrial [Member] | Commercial Loans [Member]
Loans	157,193	142,499
Commercial and Industrial [Member] | Accruing Loans [Member]
Loans	4,430	5,124
Commercial and Industrial [Member] | Nonaccrual Loans [Member]
Loans	31
Commercial and Industrial [Member] | Subtotal, Other Loans [Member]
Loans	4,461	5,124
Commercial and Industrial [Member] | Pass [Member] | Commercial Loans [Member]
Loans	155,223	140,589
Commercial and Industrial [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans	612	426
Commercial and Industrial [Member] | Substandard [Member] | Commercial Loans [Member]
Loans	1,358	1,484
Commercial and Industrial [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans
Commercial and Industrial [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans
Consumer Portfolio Segment [Member]
Loans	129,192	138,239
Consumer Portfolio Segment [Member] | Commercial Loans [Member]
Loans	3,135	3,111
Consumer Portfolio Segment [Member] | Accruing Loans [Member]
Loans	125,447	134,457
Consumer Portfolio Segment [Member] | Nonaccrual Loans [Member]
Loans	610	671
Consumer Portfolio Segment [Member] | Subtotal, Other Loans [Member]
Loans	126,057	135,128
Consumer Portfolio Segment [Member] | Pass [Member] | Commercial Loans [Member]
Loans	3,135	3,111
Consumer Portfolio Segment [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans
Consumer Portfolio Segment [Member] | Substandard [Member] | Commercial Loans [Member]
Loans
Consumer Portfolio Segment [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans
Consumer Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans
State and Political Subdivisions [Member]
Loans	49,953	43,908
State and Political Subdivisions [Member] | Commercial Loans [Member]
Loans	49,953	43,908
State and Political Subdivisions [Member] | Accruing Loans [Member]
Loans
State and Political Subdivisions [Member] | Nonaccrual Loans [Member]
Loans
State and Political Subdivisions [Member] | Subtotal, Other Loans [Member]
Loans
State and Political Subdivisions [Member] | Pass [Member] | Commercial Loans [Member]
Loans	49,953	43,908
State and Political Subdivisions [Member] | Special Mention [Member] | Commercial Loans [Member]
Loans
State and Political Subdivisions [Member] | Substandard [Member] | Commercial Loans [Member]
Loans
State and Political Subdivisions [Member] | Doubtful [Member] | Commercial Loans [Member]
Loans
State and Political Subdivisions [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Loans [Member]
Loans