Note 8 - Investment Securities (Details Textual) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Total	$ 4,500		$ 4,500
Equity Securities, FV-NI, Unrealized Gain (Loss), Total	(3,700)	$ 3,000	1,257	$ (3,628)
Equity Securities, FV-NI, Current	$ 23,123		$ 23,123		$ 22,319
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	195		195		88
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Ending Balance	$ 0		$ 0
Debt Securities, Available-for-Sale, Transfer in, Allowance for Credit Loss, Expense	0	$ 0	0	$ 0
Debt Securities, Available-for-Sale, Total	1,414,411		1,414,411		$ 1,127,309
Asset Pledged as Collateral [Member] | Public Deposits and Other Borrowings [Member]
Debt Securities, Available-for-Sale, Total	$ 144,300		$ 144,300		$ 30,500
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	160		160		70
Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions	21		21		12
Debt Securities, Available-for-Sale, Total	$ 210,702		$ 210,702		$ 142,018