Note 12 - Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Tax provision at Federal statutory rate, amount	$ 84,752	$ 99,233	$ 80,187
Tax provision at Federal statutory rate, percent	21.00%	21.00%	21.00%
State income taxes, net of Federal income tax benefit, amount	$ 36,107	$ 44,837	$ 37,602
State income taxes, net of Federal income tax benefit, percent	9.00%	9.50%	9.80%
Excess deduction for stock option and RSUs, amount	$ (586)	$ (140)	$ (20)
Excess deduction for stock option and RSUs, percent	(0.10%)	0.00%	0.00%
Low income housing and other tax credits, amount	$ (73,715)	$ (34,231)	$ (32,795)
Low income housing and other tax credits, percent	(18.30%)	(7.20%)	(8.60%)
Other, net, amount	$ 2,900	$ 2,195	$ (1,435)
Other, net, percent	0.70%	0.40%	(0.30%)
Total income tax expense, amount	$ 49,458	$ 111,894	$ 83,539
Total income tax expense, percent	12.30%	23.70%	21.90%