Note 3 - Loans - Loans by Loan Portfolio Class (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans	$ 2,335,120	$ 2,305,375
Commercial and Industrial Portfolio Segment [Member]
Loans	750,728	736,841
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans	174,310	192,348
Undevelopment Land Portfolio Segment [Member]
Loans	20,989	21,496
Real Estate Mortgage Portfolio Segment [Member]
Loans	1,351,662	1,319,520
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans	576,810	538,886
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans	397,804	408,292
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans	261,707	249,498
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans	51,925	55,325
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans	63,416	67,519
Consumer Portfolio Segment [Member]
Loans	$ 37,431	$ 35,170