Note 13 - Stockholders' Equity and Earnings Per Share - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Beginning balance, loss, net of tax	$ 2,474,040	$ 2,446,251	$ 2,418,144
Total other comprehensive (loss)/income, net of tax	16,879	(99,230)	(8,375)
Ending balance, loss, net of tax	2,736,575	2,474,040	2,446,251
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Beginning balance, loss, net of tax	(104,832)	211
Net unrealized (losses)/gains arising during the period, pre-tax	24,315	(149,124)
Net unrealized (losses)/gains arising during the period, tax	7,786	(44,081)
Net unrealized (losses)/gains arising during the period, net of tax	16,529	(105,043)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	(3,000)	0
Reclassification adjustment for net losses/(gains) included in net income, tax	(887)	0
Reclassification adjustment for net losses/(gains) included in net income, net of tax	(2,113)	0
Total other comprehensive (loss)/income, pre-tax	27,315	(149,124)
Total other comprehensive (loss)/income, tax	8,673	(44,081)
Total other comprehensive (loss)/income, net of tax	18,642	(105,043)
Ending balance, loss, net of tax	(86,190)	(104,832)	211
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Beginning balance, loss, net of tax	2,537	(3,276)
Net unrealized (losses)/gains arising during the period, pre-tax	(2,503)	10,864
Net unrealized (losses)/gains arising during the period, tax	(740)	3,211
Net unrealized (losses)/gains arising during the period, net of tax	(1,763)	7,653
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	0	2,612
Reclassification adjustment for net losses/(gains) included in net income, tax	0	772
Reclassification adjustment for net losses/(gains) included in net income, net of tax	0	1,840
Total other comprehensive (loss)/income, pre-tax	(2,503)	8,252
Total other comprehensive (loss)/income, tax	(740)	2,439
Total other comprehensive (loss)/income, net of tax	(1,763)	5,813
Ending balance, loss, net of tax	774	2,537	(3,276)
AOCI Attributable to Parent [Member]
Beginning balance, loss, net of tax	(102,295)	(3,065)	5,310
Net unrealized (losses)/gains arising during the period, pre-tax	21,812	(138,260)
Net unrealized (losses)/gains arising during the period, tax	7,046	(40,870)
Net unrealized (losses)/gains arising during the period, net of tax	14,766	(97,390)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	(3,000)	2,612
Reclassification adjustment for net losses/(gains) included in net income, tax	(887)	772
Reclassification adjustment for net losses/(gains) included in net income, net of tax	(2,113)	1,840
Total other comprehensive (loss)/income, pre-tax	24,812	(140,872)
Total other comprehensive (loss)/income, tax	7,933	(41,642)
Total other comprehensive (loss)/income, net of tax	16,879	(99,230)	(8,375)
Ending balance, loss, net of tax	$ (85,416)	$ (102,295)	$ (3,065)