Note 5 - Loans - Non-accrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Non-accrual loans	$ 6,511	$ 5,295
Commercial and Industrial Portfolio Segment [Member]
Non-accrual loans	321	1,767
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Non-accrual loans	664	538
Undevelopment Land Portfolio Segment [Member]
Non-accrual loans	474	474
Real Estate Mortgage Portfolio Segment [Member]
Non-accrual loans	5,052	2,516
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Non-accrual loans	52	107
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Non-accrual loans	3,332	1,042
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Non-accrual loans	1,637	984
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	31	383
Consumer Portfolio Segment [Member]
Non-accrual loans