Note 17 - Fair Value Measurements and Fair Value of Financial Instruments - Fair Value Hierarchy 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
Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale		240,500	0
Equity securities		22,158	22,319
Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale		1,232,848	1,127,309
Equity securities		0	0
Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale		0	0
Equity securities		0	0
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
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and due from banks		195,440	134,141
Short-term investments		966,962	2,315,563
Securities available-for-sale		240,500	0
Loans, net	[1]	0	0
Equity securities		22,158	22,319
Investment in Federal Home Loan Bank stock		0	0
Deposits		0	0
Advances from Federal Home Loan Bank		0	0
Other borrowings		0	0
Long-term debt		0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | Warrants [Member]
Warrants		0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and due from banks		0	0
Short-term investments		0	0
Securities available-for-sale		1,232,848	1,127,309
Loans, net	[1]	0	0
Equity securities		0	0
Investment in Federal Home Loan Bank stock		17,250	17,250
Deposits		0	0
Advances from Federal Home Loan Bank		482,737	21,279
Other borrowings		0	0
Long-term debt		68,231	62,274
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Warrants [Member]
Warrants		0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and due from banks		0	0
Short-term investments		0	0
Securities available-for-sale		0	0
Loans, net	[1]	17,944,588	16,499,869
Equity securities		0	0
Investment in Federal Home Loan Bank stock		0	0
Deposits		18,572,387	18,051,720
Advances from Federal Home Loan Bank		0	0
Other borrowings		18,385	18,945
Long-term debt		0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [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.