Note 18 - Stockholders' Equity - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Beginning balance, loss, net of tax	$ 2,446,251	$ 2,418,144
Total other comprehensive (loss)/income, net of tax	(42,912)	(3,624)
Ending balance, loss, net of tax	2,422,230	2,460,947
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Beginning balance, loss, net of tax	211	12,200
Net unrealized (losses)/gains arising during the period, pre-tax	(65,256)	(6,085)
Net unrealized (losses)/gains arising during the period, tax	(19,290)	(1,799)
Net unrealized (losses)/gains arising during the period, net of tax	(45,966)	(4,286)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	0	853
Reclassification adjustment for net losses/(gains) included in net income, tax	0	252
Reclassification adjustment for net losses/(gains) included in net income, net of tax	0	601
Total other comprehensive (loss)/income, pre-tax	(65,256)	(6,938)
Total other comprehensive (loss)/income, tax	(19,290)	(2,051)
Total other comprehensive (loss)/income, net of tax	(45,966)	(4,887)
Ending balance, loss, net of tax	(45,755)	7,313
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Beginning balance, loss, net of tax	(3,276)	(6,890)
Net unrealized (losses)/gains arising during the period, pre-tax	4,336	1,793
Net unrealized (losses)/gains arising during the period, tax	1,282	530
Net unrealized (losses)/gains arising during the period, net of tax	3,054	1,263
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	0	0
Reclassification adjustment for net losses/(gains) included in net income, tax	0	0
Reclassification adjustment for net losses/(gains) included in net income, net of tax	0	0
Total other comprehensive (loss)/income, pre-tax	4,336	1,793
Total other comprehensive (loss)/income, tax	1,282	530
Total other comprehensive (loss)/income, net of tax	3,054	1,263
Ending balance, loss, net of tax	(222)	(5,627)
AOCI Attributable to Parent [Member]
Beginning balance, loss, net of tax	(3,065)	5,310
Net unrealized (losses)/gains arising during the period, pre-tax	(60,920)	(4,292)
Net unrealized (losses)/gains arising during the period, tax	(18,008)	(1,269)
Net unrealized (losses)/gains arising during the period, net of tax	(42,912)	(3,023)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	0	853
Reclassification adjustment for net losses/(gains) included in net income, tax	0	252
Reclassification adjustment for net losses/(gains) included in net income, net of tax	0	601
Total other comprehensive (loss)/income, pre-tax	(60,920)	(5,145)
Total other comprehensive (loss)/income, tax	(18,008)	(1,521)
Total other comprehensive (loss)/income, net of tax	(42,912)	(3,624)
Ending balance, loss, net of tax	$ (45,977)	$ 1,686