Note 3 - Loans - Non-accrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Non-accrual loans	$ 11,422	$ 6,511
Commercial and Industrial Portfolio Segment [Member]
Non-accrual loans	3,321	321
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Non-accrual loans	670	664
Undevelopment Land Portfolio Segment [Member]
Non-accrual loans	570	474
Real Estate Mortgage Portfolio Segment [Member]
Non-accrual loans	6,770	5,052
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Non-accrual loans		52
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Non-accrual loans	5,149	3,332
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Non-accrual loans	1,592	1,637
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Non-accrual loans
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Non-accrual loans	29	31
Consumer Portfolio Segment [Member]
Non-accrual loans	$ 91