Note 20 - Concentrations of Credit - (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, before Allowance for Credit Loss	$ 4,992,785	$ 4,606,176
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, before Allowance for Credit Loss	3,570,120	3,398,858
Commercial Real Estate Portfolio Segment [Member] \| Nonfarm Nonresidential [Member]
Financing Receivable, before Allowance for Credit Loss	$ 2,000,000	$ 1,800,000
Commercial Real Estate Portfolio Segment [Member] \| Nonfarm Nonresidential [Member] \| Loan Secured by Real Estate [Member] \| Credit Concentration Risk [Member]
Concentration Risk, Percentage	39.80%	39.70%
Commercial Real Estate Portfolio Segment [Member] \| Construction and Land [Member]
Financing Receivable, before Allowance for Credit Loss	$ 669,800	$ 722,100
Commercial Real Estate Portfolio Segment [Member] \| Construction and Land [Member] \| Loan Secured by Real Estate [Member] \| Credit Concentration Risk [Member]
Concentration Risk, Percentage	13.40%	15.70%

Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

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+ Details