Note 3 - Loans - Non-accrual Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Non-accrual loans	$ 3,982	$ 6,511
Commercial and Industrial Portfolio Segment [Member]
Non-accrual loans	450	321
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Non-accrual loans	380	664
Undevelopment Land Portfolio Segment [Member]
Non-accrual loans	474	474
Real Estate Mortgage Portfolio Segment [Member]
Non-accrual loans	2,678	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	1,056	3,332
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Non-accrual loans	1,507	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	115	31
Consumer Portfolio Segment [Member]
Non-accrual loans