Note 6 - Loans Receivable and Allowance for Loan Losses - Non-accrual Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Non-accrual loans	$ 14,106	$ 14,845
Commercial Real Estate Portfolio Segment [Member]
Non-accrual loans	7,426	8,963
Construction and Land Development Portfolio Segment [Member]
Non-accrual loans
Commercial Portfolio Segment [Member]
Non-accrual loans	3,885	2,895
Owner Occupied Real Estate [Member]
Non-accrual loans	2,004	2,136
Consumer Portfolio Segment [Member]
Non-accrual loans	791	851
Residential Portfolio Segment [Member]
Non-accrual loans