Note 6 - Other Assets - Summary of Major Components of Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Cash surrender value of life insurance other than BOLI	$ 19,880		$ 17,843
Net deferred tax asset	45,647		47,236
Investments in tax credit partnerships	177,194		175,056
Swap assets	2,489		5,133
Prepaid assets	4,242		5,873
WM&T fees receivable	4,459		4,205
Mortgage servicing rights	11,908	$ 12,197	13,082	$ 13,558	$ 14,116	$ 15,219
Other real estate owned	10		10
Other	14,537		18,922
Total other assets	$ 280,366		$ 287,360