Note 4 - Loans and Allowance for Credit Losses on Loans - Credit Card Loan Payment Activity (Details) - USD ($) $ in Thousands		Mar. 31, 2023	Dec. 31, 2022
Loans	[1]	$ 5,243,104	$ 5,205,918
Credit Card Receivable [Member]
Loans		21,738	20,413
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans		21,738	20,413
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Performing Financial Instruments [Member]
Loans		21,494	20,413
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Nonperforming Financial Instruments [Member]
Loans		$ 244	$ 0

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