Note 5 - Loans - Loans by Loan Portfolio Class (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans	$ 2,305,375	$ 2,033,007	$ 1,868,550
Commercial and Industrial Portfolio Segment [Member]
Loans	736,841	644,398	571,754
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans	192,348	134,482	95,733
Undevelopment Land Portfolio Segment [Member]
Loans	21,496	21,185	21,268
Real Estate Mortgage Portfolio Segment [Member]
Loans	1,319,520	1,197,411	1,150,399
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans	538,886	436,989
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans	408,292	420,666
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans	249,498	226,575
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans	55,325	50,115
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans	67,519	63,066
Consumer Portfolio Segment [Member]
Loans	$ 35,170	$ 35,531	$ 29,396