Note 6 - Loans Receivable and Allowance for Loan Losses - Non-accrual Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Non-accrual loans	$ 13,479	$ 14,845
Commercial Real Estate Portfolio Segment [Member]
Non-accrual loans	7,159	8,963
Construction and Land Development Portfolio Segment [Member]
Non-accrual loans
Commercial Portfolio Segment [Member]
Non-accrual loans	3,868	2,895
Owner Occupied Real Estate [Member]
Non-accrual loans	1,651	2,136
Consumer Portfolio Segment [Member]
Non-accrual loans	801	851
Residential Portfolio Segment [Member]
Non-accrual loans