Note 4 - Loans and Allowance for Loan Losses - Risk Category of Commercial Loans by Class of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans receivable	$ 775,086	$ 772,774
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	227,548	222,136
Commercial and Industrial Portfolio Segment [Member]
Loans receivable	102,570	100,023
Commercial Portfolio Segment [Member]
Loans receivable	330,118	322,159
Commercial Real Estate Owner Occupied [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	55,515	55,825
Commercial Real Estate Nonowner Occupied [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	137,141	131,398
Construction Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	34,892	34,913
Pass [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable	92,468	89,749
Pass [Member] | Commercial Portfolio Segment [Member]
Loans receivable	305,035	297,946
Pass [Member] | Commercial Real Estate Owner Occupied [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	47,876	49,486
Pass [Member] | Commercial Real Estate Nonowner Occupied [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	129,848	123,847
Pass [Member] | Construction Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	34,843	34,864
Criticized [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable	4,071	298
Criticized [Member] | Commercial Portfolio Segment [Member]
Loans receivable	12,014	3,187
Criticized [Member] | Commercial Real Estate Owner Occupied [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	1,634	2,889
Criticized [Member] | Commercial Real Estate Nonowner Occupied [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	6,309
Criticized [Member] | Construction Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable
Classified [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable	6,031	9,976
Classified [Member] | Commercial Portfolio Segment [Member]
Loans receivable	13,069	21,026
Classified [Member] | Commercial Real Estate Owner Occupied [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	6,005	3,450
Classified [Member] | Commercial Real Estate Nonowner Occupied [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	984	7,551
Classified [Member] | Construction Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable	$ 49	$ 49