Note 3 - Loans and Allowance for Credit Losses on Loans - Credit Card Loan Payment Activity (Details) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Loans	[1]	$ 5,849,715	$ 5,771,038
Credit Card Receivable [Member]
Loans		24,104	23,632
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member]
Loans		24,104	23,632
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Performing Financial Instruments [Member]
Loans		24,006	23,512
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Nonperforming Financial Instruments [Member]
Loans		$ 98	$ 120

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