Note 4 - Loans and Allowance for Credit Losses - Loans by Loan Portfolio Class (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Loans	[1]	$ 2,937,366	$ 2,845,016	[2]
Home Equity Line of Credit [Member]
Loans		107,121	103,854
Commercial Real Estate Portfolio Segment [Member]
Loans		1,275,818	1,220,612
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Loans		799,284	746,283
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Loans		476,534	474,329
Commercial and Industrial Portfolio Segment [Member]
Loans			870,511
Commercial and Industrial Portfolio Segment [Member] | Term [Member]
Loans		535,325	457,298
Commercial and Industrial Portfolio Segment [Member] | Lines of Credit [Member]
Loans		348,543	381,502
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Loans	[3]		213,822
Undevelopment Land Portfolio Segment [Member]
Loans			46,360
Real Estate Mortgage Portfolio Segment [Member]
Loans			1,666,856
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Loans			736,618
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Loans			473,783
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Loans			334,358
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Loans			48,620
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Loans			73,477
Total Commercial and Industrial Portfolio Segment [Member]
Loans		883,868	838,800
Residential Real Estate Portfolio Segment [Member]
Loans		353,955	352,601
Residential Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Loans		134,734	134,995
Residential Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Loans		219,221	217,606
Construction and Development [Member]
Loans		246,040	255,816
Consumer Portfolio Segment [Member]
Loans		44,939	47,467
Finance Leases Portfolio Segment [Member]
Loans		15,476	16,003
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans		$ 10,149	$ 9,863

[1] Total loans are presented inclusive of premiums, discounts and net loan origination fees and costs

[2] Total loans are presented inclusive of premiums, discounts, and net loan origination fees and costs.

[3] Consists of land acquired for development by the borrower, but for which no development has yet taken place.