Note 18 - Stockholders' Equity - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Beginning balance, loss, net of tax	$ 2,431,532	$ 2,452,357	$ 2,446,251	$ 2,418,144
Total other comprehensive (loss)/income, net of tax	(41,546)	(2,740)	(109,809)	(5,678)
Ending balance, loss, net of tax	2,419,559	2,463,291	2,419,559	2,463,291
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Beginning balance, loss, net of tax	(72,210)	7,560	211	12,200
Net unrealized (losses)/gains arising during the period, pre-tax	(61,316)	(4,588)	(164,128)	(10,322)
Net unrealized (losses)/gains arising during the period, tax	(18,125)	(1,356)	(48,516)	(3,051)
Net unrealized (losses)/gains arising during the period, net of tax	(43,191)	(3,232)	(115,612)	(7,271)
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	(61,316)	(4,588)	(164,128)	(11,175)
Total other comprehensive (loss)/income, tax	(18,125)	(1,356)	(48,516)	(3,303)
Total other comprehensive (loss)/income, net of tax	(43,191)	(3,232)	(115,612)	(7,872)
Ending balance, loss, net of tax	(115,401)	4,328	(115,401)	4,328
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Beginning balance, loss, net of tax	882	(5,188)	(3,276)	(6,890)
Net unrealized (losses)/gains arising during the period, pre-tax	2,677	2,224	11,060	7,600
Net unrealized (losses)/gains arising during the period, tax	791	657	3,269	2,247
Net unrealized (losses)/gains arising during the period, net of tax	1,886	1,567	7,791	5,353
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	342	1,526	2,822	4,485
Reclassification adjustment for net losses/(gains) included in net income, tax	101	451	834	1,326
Reclassification adjustment for net losses/(gains) included in net income, net of tax	241	1,075	1,988	3,159
Total other comprehensive (loss)/income, pre-tax	2,335	698	8,238	3,115
Total other comprehensive (loss)/income, tax	690	206	2,435	921
Total other comprehensive (loss)/income, net of tax	1,645	492	5,803	2,194
Ending balance, loss, net of tax	2,527	(4,696)	2,527	(4,696)
AOCI Attributable to Parent [Member]
Beginning balance, loss, net of tax	(71,328)	2,372	(3,065)	5,310
Net unrealized (losses)/gains arising during the period, pre-tax	(58,639)	(2,364)	(153,068)	(2,722)
Net unrealized (losses)/gains arising during the period, tax	(17,334)	(699)	(45,247)	(804)
Net unrealized (losses)/gains arising during the period, net of tax	(41,305)	(1,665)	(107,821)	(1,918)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax	342	1,526	2,822	5,338
Reclassification adjustment for net losses/(gains) included in net income, tax	101	451	834	1,578
Reclassification adjustment for net losses/(gains) included in net income, net of tax	241	1,075	1,988	3,760
Total other comprehensive (loss)/income, pre-tax	(58,981)	(3,890)	(155,890)	(8,060)
Total other comprehensive (loss)/income, tax	(17,435)	(1,150)	(46,081)	(2,382)
Total other comprehensive (loss)/income, net of tax	(41,546)	(2,740)	(109,809)	(5,678)
Ending balance, loss, net of tax	$ (112,874)	$ (368)	$ (112,874)	$ (368)