Note 4 - Loans and Allowance for Loan Losses - Risk Category of Commercial Loans by Class of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans receivable	$ 756,905	$ 734,901
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	212,127	214,007
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans receivable	75,829	77,605
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans receivable	93,083	90,532
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	43,215	45,870
Commercial and Industrial Portfolio Segment [Member]
Loans receivable	102,950	100,589
Commercial Portfolio Segment [Member]
Loans receivable	315,077	314,596
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans receivable	64,378	66,495
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans receivable	86,284	83,103
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	42,504	45,325
Pass [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable	96,611	94,091
Pass [Member] | Commercial Portfolio Segment [Member]
Loans receivable	289,777	289,014
Criticized [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans receivable	2,124	428
Criticized [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans receivable	2,240	2,364
Criticized [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable
Criticized [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable	1,355	188
Criticized [Member] | Commercial Portfolio Segment [Member]
Loans receivable	5,719	2,980
Classified [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans receivable	9,327	10,682
Classified [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans receivable	4,559	5,065
Classified [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	711	545
Classified [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable	4,984	6,310
Classified [Member] | Commercial Portfolio Segment [Member]
Loans receivable	$ 19,581	$ 22,602