Note 8 - Loans - Components of Loans in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Loans held for investment	$ 19,429,396	$ 19,548,140
Less: Allowance for loan losses	(154,589)	(154,562)	$ (144,884)	$ (146,485)
Unamortized deferred loan fees, net	(11,737)	(10,720)
Loans held for investment, net	19,263,070	19,382,858
Loans held for sale	23,171	0
Commercial Portfolio Segment [Member]
Loans held for investment	3,132,580	3,305,048
Less: Allowance for loan losses	(51,290)	(53,791)	(45,975)	(49,435)
Real Estate Construction Portfolio Segment [Member]
Loans held for investment	382,775	422,647
Less: Allowance for loan losses	(8,539)	(8,180)	(10,900)	(10,417)
Commercial Real Estate Portfolio Segment [Member]
Loans held for investment	9,821,807	9,729,581
Less: Allowance for loan losses	(77,049)	(74,428)	(70,367)	(68,366)
Residential Portfolio Segment [Member]
Loans held for investment	5,841,846	5,838,747
Equity Lines Portfolio Segment [Member]
Loans held for investment	245,222	245,919
Installment and Other Loans [Member ]
Loans held for investment	5,166	6,198
Less: Allowance for loan losses	$ (10)	$ (23)	$ (9)	$ (35)

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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