Note 6 - Loans Receivable and Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
With no related allowance - Recorded investment	$ 13,710	$ 15,270
With no related allowance - Unpaid principal balance	17,933	19,666
With related allowance - Recorded investment	7,615	9,446
With related allowance - Unpaid principal balance	8,747	9,502
Related allowance	1,313	2,790
Recorded investment	21,325	24,716
Unpaid principal balance	26,680	29,168
Commercial Real Estate Portfolio Segment [Member]
With no related allowance - Recorded investment	8,894	9,264
With no related allowance - Unpaid principal balance	8,899	9,268
With related allowance - Recorded investment	4,616	6,151
With related allowance - Unpaid principal balance	5,500	6,165
Related allowance	194	1,964
Recorded investment	13,510	15,415
Unpaid principal balance	14,399	15,433
Construction and Land Development Portfolio Segment [Member]
With no related allowance - Recorded investment
With no related allowance - Unpaid principal balance
With related allowance - Recorded investment
With related allowance - Unpaid principal balance
Related allowance
Recorded investment
Unpaid principal balance
Commercial Portfolio Segment [Member]
With no related allowance - Recorded investment	1,969	2,756
With no related allowance - Unpaid principal balance	5,728	6,674
With related allowance - Recorded investment	2,010	1,745
With related allowance - Unpaid principal balance	2,198	1,752
Related allowance	792	374
Recorded investment	3,979	4,501
Unpaid principal balance	7,926	8,426
Owner Occupied Real Estate [Member]
With no related allowance - Recorded investment	2,198	2,595
With no related allowance - Unpaid principal balance	2,298	2,743
With related allowance - Recorded investment	837	1,203
With related allowance - Unpaid principal balance	894	1,206
Related allowance	242	235
Recorded investment	3,035	3,798
Unpaid principal balance	3,192	3,949
Consumer Portfolio Segment [Member]
With no related allowance - Recorded investment	649	655
With no related allowance - Unpaid principal balance	1,008	981
With related allowance - Recorded investment	152	347
With related allowance - Unpaid principal balance	155	379
Related allowance	85	217
Recorded investment	801	1,002
Unpaid principal balance	1,163	1,360
Residential Portfolio Segment [Member]
With no related allowance - Recorded investment
With no related allowance - Unpaid principal balance
With related allowance - Recorded investment
With related allowance - Unpaid principal balance
Related allowance
Recorded investment
Unpaid principal balance