Note 17 - Fair Value Measurements and Fair Value of Financial Instruments - Fair Value Hierarchy of Financial Instruments (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Equity securities		$ 40,406	$ 22,158
Warrants		54,268	90,451
Fair Value, Inputs, Level 1 [Member]
Equity securities		40,406	22,158
Fair Value, Inputs, Level 2 [Member]
Equity securities		0	0
Fair Value, Inputs, Level 3 [Member]
Equity securities		0	0
Estimate of Fair Value Measurement [Member]
Cash and due from banks		173,988	195,440
Short-term investments		654,813	966,962
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
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and due from banks		173,988	195,440
Short-term investments		654,813	966,962
Loans, net	[1]	0	0
Equity securities		40,406	22,158
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
Loans, net	[1]	0	0
Equity securities		0	0
Investment in Federal Home Loan Bank stock		17,746	17,250
Deposits		0	0
Advances from Federal Home Loan Bank		536,996	482,737
Other borrowings		0	0
Long-term debt		72,304	68,231
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
Loans, net	[1]	19,605,152	17,944,588
Equity securities		0	0
Investment in Federal Home Loan Bank stock		0	0
Deposits		19,347,070	18,572,387
Advances from Federal Home Loan Bank		0	0
Other borrowings		13,978	18,385
Long-term debt		0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [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.