Note 6 - Other Assets - Summary of Major Components of Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Cash surrender value of life insurance other than BOLI	$ 16,940		$ 15,496
Net deferred tax asset	51,054		54,145
Investments in tax credit partnerships	55,530		13,969
Swap assets	12,628		10,727
Prepaid assets	4,073		5,721
Trust fees receivable	3,548		3,354
Mortgage servicing rights	14,116	$ 14,623	15,219	$ 16,504	$ 16,877	$ 4,528
Other real estate owned	677		677
Other	14,518		15,680
Total other assets	$ 173,084		$ 134,988