Note 4 - Loans and Allowance for Credit Losses - Credit Card Loan Payment Activity (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Loans	[1]	$ 2,937,366	$ 2,845,016	[2]
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans		10,149	$ 9,863
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Performing Financial Instruments [Member]
Loans		10,149
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Nonperforming Financial Instruments [Member]
Loans		$ 0

[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.