Note 5 - Loans and Allowance for Loan Losses - Risk Category of Commercial Loans by Class of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans receivable	$ 72,943	$ 62,287
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans receivable	88,613	61,577
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	33,951	23,080
Pass [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable	94,011	70,852
Pass [Member] | Commercial Portfolio Segment [Member]
Loans receivable	289,518	217,796
Criticized [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans receivable	370	6,738
Criticized [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans receivable	367	6,305
Criticized [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable
Criticized [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable		5,232
Criticized [Member] | Commercial Portfolio Segment [Member]
Loans receivable	737	18,275
Classified [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans receivable	8,891	4,433
Classified [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans receivable	9,943	4,120
Classified [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	543	772
Classified [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans receivable	3,181	5,852
Classified [Member] | Commercial Portfolio Segment [Member]
Loans receivable	22,558	15,177
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans receivable	82,204	73,458
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans receivable	98,923	72,002
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	34,494	23,852
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	215,621	169,312
Commercial and Industrial Portfolio Segment [Member]
Loans receivable	97,192	81,936
Commercial Portfolio Segment [Member]
Loans receivable	312,813	251,248
Loans receivable	$ 721,587	$ 585,752