Note 17 - Fair Value Measurements and Fair Value of Financial Instruments - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Dec. 31, 2022	Dec. 31, 2021
Securities available-for-sale		$ 1,473,348	$ 1,127,309
Equity securities		22,158	22,319
Warrants		90,451	10,090
Foreign exchange contracts with gain		72,996	181,997
Foreign exchange contracts with gain, fair value		448	1,113
Interest rate swaps		817,615	904,635
Interest rate swaps, fair value		44,443	10,090
Option contracts		0	676
Option contracts, fair value		0	3
Foreign exchange contracts with loss		170,213	51,782
Foreign exchange contracts with loss, fair value		942	327
Interest rate swaps		595,426	872,400
Interest rate swaps, fair value		51,864	12,642
Commitments to extend credit		3,630,304	3,297,362
Commitments to extend credit, fair value		(14,797)	(12,594)
Standby letters of credit		315,821	266,490
Standby letters of credit, fair value		(2,738)	(2,640)
Other letters of credit		29,416	16,652
Other letters of credit, fair value		(33)	(13)
Reported Value Measurement [Member]
Cash and due from banks		195,440	134,141
Short-term investments		966,962	2,315,563
Securities available-for-sale		1,473,348	1,127,309
Loans, net		18,100,898	16,202,001
Equity securities		22,158	22,319
Investment in Federal Home Loan Bank stock		17,250	17,250
Deposits		18,505,279	18,058,842
Advances from Federal Home Loan Bank		485,000	20,000
Other borrowings		22,600	23,145
Long-term debt		119,136	119,136
Reported Value Measurement [Member] | Warrants [Member]
Warrants		50	23
Estimate of Fair Value Measurement [Member]
Cash and due from banks		195,440	134,141
Short-term investments		966,962	2,315,563
Securities available-for-sale		1,473,348	1,127,309
Loans, net	[1]	17,944,588	16,499,869
Equity securities		22,158	22,319
Investment in Federal Home Loan Bank stock		17,250	17,250
Deposits		18,572,387	18,051,720
Advances from Federal Home Loan Bank		482,737	21,279
Other borrowings		18,385	18,945
Long-term debt		68,231	62,274
Estimate of Fair Value Measurement [Member] | Warrants [Member]
Warrants		$ 50	$ 23

[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.