Note 3 - Loans - Internally Assigned Risk Grades of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Loans	$ 2,272,778	$ 2,305,375
Commercial and Industrial Portfolio Segment [Member]
Loans	736,633	736,841
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans	165,832	192,348
Undevelopment Land Portfolio Segment [Member]
Loans	21,207	21,496
Real Estate Mortgage Portfolio Segment [Member]
Loans	1,314,397	1,319,520
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans	546,957	538,886
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans	406,209	408,292
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans	244,349	249,498
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans	51,076	55,325
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans	65,806	67,519
Consumer Portfolio Segment [Member]
Loans	34,709	35,170
Pass [Member]
Loans	2,232,227	2,267,103
Pass [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans	710,959	714,025
Pass [Member] | Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans	165,063	191,455
Pass [Member] | Undevelopment Land Portfolio Segment [Member]
Loans	20,703	21,022
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member]
Loans	1,300,957	1,305,562
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans	546,391	538,688
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans	395,895	396,997
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans	242,341	247,888
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans	50,901	55,279
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans	65,429	66,710
Pass [Member] | Consumer Portfolio Segment [Member]
Loans	34,545	35,039
Special Mention [Member]
Loans	24,443	22,226
Special Mention [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans	16,489	14,266
Special Mention [Member] | Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans
Special Mention [Member] | Undevelopment Land Portfolio Segment [Member]
Loans
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member]
Loans	7,848	7,960
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans	375
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans	6,989	7,960
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans	431
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans	53
Special Mention [Member] | Consumer Portfolio Segment [Member]
Loans	106
Substandard [Member] | Performing Financial Instruments [Member]
Loans	10,021	9,339
Substandard [Member] | Nonperforming Financial Instruments [Member]
Loans	6,087	6,707
Substandard [Member] | Commercial and Industrial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	6,342	5,850
Substandard [Member] | Commercial and Industrial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	2,843	2,700
Substandard [Member] | Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	325	355
Substandard [Member] | Construction and Development Excluding Undeveloped Land Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	444	538
Substandard [Member] | Undevelopment Land Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	30
Substandard [Member] | Undevelopment Land Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	474	474
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	3,324	3,134
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member] | Commercial Investment [Member]
Loans	22	5
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member] | Owner Occupied Commercial [Member]
Loans	2,089	2,111
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member] | One to Four Family Residential [Member]
Loans	889	592
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member] | Home Equity First Lien [Member]
Loans
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member] | Home Equity Junior Lien [Member]
Loans	324	426
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	2,268	2,864
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Commercial Investment [Member]
Loans	169	193
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Owner Occupied Commercial [Member]
Loans	1,236	1,224
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | One to Four Family Residential [Member]
Loans	688	1,018
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Home Equity First Lien [Member]
Loans	175	46
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Home Equity Junior Lien [Member]
Loans		383
Substandard [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans
Substandard [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	58	131
Doubtful [Member]
Loans
Doubtful [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans
Doubtful [Member] | Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans
Doubtful [Member] | Undevelopment Land Portfolio Segment [Member]
Loans
Doubtful [Member] | Real Estate Mortgage Portfolio Segment [Member]
Loans
Doubtful [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans
Doubtful [Member] | Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans
Doubtful [Member] | Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans
Doubtful [Member] | Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans
Doubtful [Member] | Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans
Doubtful [Member] | Consumer Portfolio Segment [Member]
Loans