Note 3 - Loans - Internally Assigned Risk Grades of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans	$ 2,309,668	$ 2,305,375
Commercial and Industrial Portfolio Segment [Member]
Loans	749,036	736,841
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans	175,627	192,348
Undevelopment Land Portfolio Segment [Member]
Loans	20,992	21,496
Real Estate Mortgage Portfolio Segment [Member]
Loans	1,329,597	1,319,520
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans	547,196	538,886
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans	408,558	408,292
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans	255,939	249,498
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans	52,560	55,325
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans	65,344	67,519
Consumer Portfolio Segment [Member]
Loans	34,416	35,170
Pass [Member]
Loans	2,259,081	2,267,103
Pass [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans	716,183	714,025
Pass [Member] | Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans	174,890	191,455
Pass [Member] | Undevelopment Land Portfolio Segment [Member]
Loans	20,489	21,022
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member]
Loans	1,313,282	1,305,562
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans	545,429	538,688
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans	397,218	396,997
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans	253,227	247,888
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans	52,560	55,279
Pass [Member] | Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans	64,848	66,710
Pass [Member] | Consumer Portfolio Segment [Member]
Loans	34,237	35,039
Special Mention [Member]
Loans	24,887	22,226
Special Mention [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans	15,290	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	9,493	7,960
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans	1,581
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans	6,891	7,960
Special Mention [Member] | Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans	1,012
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	9
Special Mention [Member] | Consumer Portfolio Segment [Member]
Loans	104
Substandard [Member] | Performing Financial Instruments [Member]
Loans	19,593	9,339
Substandard [Member] | Nonperforming Financial Instruments [Member]
Loans	6,107	6,707
Substandard [Member] | Commercial and Industrial Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	14,939	5,850
Substandard [Member] | Commercial and Industrial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	2,624	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	412	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	473	474
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	4,281	3,134
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member] | Commercial Investment [Member]
Loans	21	5
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member] | Owner Occupied Commercial [Member]
Loans	3,081	2,111
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Performing Financial Instruments [Member] | One to Four Family Residential [Member]
Loans	861	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	318	426
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	2,541	2,864
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Commercial Investment [Member]
Loans	165	193
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Owner Occupied Commercial [Member]
Loans	1,368	1,224
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | One to Four Family Residential [Member]
Loans	839	1,018
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Home Equity First Lien [Member]
Loans		46
Substandard [Member] | Real Estate Mortgage Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Home Equity Junior Lien [Member]
Loans	169	383
Substandard [Member] | Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans	18
Substandard [Member] | Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans	57	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