Note 18 - Stockholders' Equity - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Beginning balance, loss, net of tax	$ 2,422,230	$ 2,460,948	$ 2,446,251	$ 2,418,144
Total other comprehensive (loss)/income, net of tax	(25,351)	686	(68,263)	(2,938)
Ending balance, loss, net of tax	2,431,532	2,452,357	2,431,532	2,452,357
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Beginning balance, loss, net of tax	(45,755)	7,313	211	12,200
Net unrealized (losses)/gains arising during the period, pre-tax	(37,557)	351	(102,812)	(5,734)
Net unrealized (losses)/gains arising during the period, tax	(11,102)	104	(30,391)	(1,695)
Net unrealized (losses)/gains arising during the period, net of tax	(26,455)	247	(72,421)	(4,039)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	0	0	0	853
Reclassification adjustment for net losses/(gains) included in net income, tax	0	0	0	252
Reclassification adjustment for net losses/(gains) included in net income, net of tax	0	0	0	601
Total other comprehensive (loss)/income, pre-tax	(37,557)	351	(102,812)	(6,587)
Total other comprehensive (loss)/income, tax	(11,102)	104	(30,391)	(1,947)
Total other comprehensive (loss)/income, net of tax	(26,455)	247	(72,421)	(4,640)
Ending balance, loss, net of tax	(72,210)	7,560	(72,210)	7,560
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Beginning balance, loss, net of tax	(222)	(5,627)	(3,276)	(6,890)
Net unrealized (losses)/gains arising during the period, pre-tax	1,567	623	5,903	2,416
Net unrealized (losses)/gains arising during the period, tax	463	184	1,745	714
Net unrealized (losses)/gains arising during the period, net of tax	1,104	439	4,158	1,702
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	0	0	0	0
Reclassification adjustment for net losses/(gains) included in net income, tax	0	0	0	0
Reclassification adjustment for net losses/(gains) included in net income, net of tax	0	0	0	0
Total other comprehensive (loss)/income, pre-tax	1,567	623	5,903	2,416
Total other comprehensive (loss)/income, tax	463	184	1,745	714
Total other comprehensive (loss)/income, net of tax	1,104	439	4,158	1,702
Ending balance, loss, net of tax	882	(5,188)	882	(5,188)
AOCI Attributable to Parent [Member]
Beginning balance, loss, net of tax	(45,977)	1,686	(3,065)	5,310
Net unrealized (losses)/gains arising during the period, pre-tax	(35,990)	974	(96,909)	(3,318)
Net unrealized (losses)/gains arising during the period, tax	(10,639)	288	(28,646)	(981)
Net unrealized (losses)/gains arising during the period, net of tax	(25,351)	686	(68,263)	(2,337)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	0	0	0	853
Reclassification adjustment for net losses/(gains) included in net income, tax	0	0	0	252
Reclassification adjustment for net losses/(gains) included in net income, net of tax	0	0	0	601
Total other comprehensive (loss)/income, pre-tax	(35,990)	974	(96,909)	(4,171)
Total other comprehensive (loss)/income, tax	(10,639)	288	(28,646)	(1,233)
Total other comprehensive (loss)/income, net of tax	(25,351)	686	(68,263)	(2,938)
Ending balance, loss, net of tax	$ (71,328)	$ 2,372	$ (71,328)	$ 2,372