Note 9 - Loans - Components of Loans in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Loans	$ 19,023,822		$ 18,254,024
Less: Allowance for loan losses	(154,619)	$ (155,109)	(146,485)	$ (148,817)	$ (148,772)	$ (136,157)
Unamortized deferred loan fees, net	(9,521)		(6,641)
Loans, net	18,859,682		18,100,898
Commercial Portfolio Segment [Member]
Loans	3,090,609		3,318,778
Less: Allowance for loan losses	(44,758)	(50,579)	(49,435)	(50,399)	(49,069)	(43,394)
Real Estate Construction Portfolio Segment [Member]
Loans	474,294		559,372
Less: Allowance for loan losses	(15,111)	(12,751)	(10,417)	(6,211)	(7,276)	(6,302)
Commercial Real Estate Portfolio Segment [Member]
Loans	9,511,805		8,793,685
Less: Allowance for loan losses	(75,885)	(73,547)	(68,366)	(70,050)	(68,600)	(61,081)
Residential Portfolio Segment [Member]
Loans	5,685,844		5,252,952
Equity Lines Portfolio Segment [Member]
Loans	253,826		324,548
Installment and Other Loans [Member ]
Loans	7,444		4,689
Less: Allowance for loan losses	$ (56)	$ (18)	$ (35)	$ (128)	$ (135)	$ (1)