Note 17 - Fair Value Measurements and Fair Value of Financial Instruments - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Securities available-for-sale		$ 1,604,570	$ 1,473,348
Equity securities		40,406	22,158
Warrants		54,268	90,451
Foreign exchange contracts with gain		124,452	72,996
Foreign exchange contracts with gain, fair value		379	448
Interest rate swaps		1,406,879	817,615
Interest rate swaps, fair value		54,268	44,443
Foreign exchange contracts with loss		101,378	170,213
Foreign exchange contracts with loss, fair value		175	942
Interest rate swaps		1,078,880	595,426
Interest rate swaps, fair value		45,762	51,864
Commitments to extend credit		3,808,620	3,630,304
Commitments to extend credit, fair value		(14,344)	(14,797)
Standby letters of credit		368,618	315,821
Standby letters of credit, fair value		(2,821)	(2,738)
Other letters of credit		11,308	29,416
Other letters of credit, fair value		(10)	(33)
Reported Value Measurement [Member]
Cash and due from banks		173,988	195,440
Short-term investments		654,813	966,962
Securities available-for-sale		1,604,570	1,473,348
Loans, net		19,382,858	18,100,898
Equity securities		40,406	22,158
Investment in Federal Home Loan Bank stock		17,746	17,250
Deposits		19,325,447	18,505,279
Advances from Federal Home Loan Bank		540,000	485,000
Other borrowings		15,787	22,600
Long-term debt		119,136	119,136
Reported Value Measurement [Member] | Warrants [Member]
Warrants		0	50
Estimate of Fair Value Measurement [Member]
Cash and due from banks		173,988	195,440
Short-term investments		654,813	966,962
Securities available-for-sale		1,604,570	1,473,348
Loans, net	[1]	19,605,152	17,944,588
Equity securities		40,406	22,158
Investment in Federal Home Loan Bank stock		17,746	17,250
Deposits		19,347,070	18,572,387
Advances from Federal Home Loan Bank		536,996	482,737
Other borrowings		13,978	18,385
Long-term debt		72,304	68,231
Estimate of Fair Value Measurement [Member] | Warrants [Member]
Warrants		$ 0	$ 50

[1] In accordance with the prospective adoption of ASU 2016-01, the fair value of loans as of December 31, 2019 & 2018 was measured using an exit price notion.