Note 6 - Other Assets - Summary of Major Components of Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023
Cash surrender value of life insurance other than BOLI	$ 21,024		$ 19,895
Net deferred tax asset	47,374		51,646
Investments in tax credit partnerships	198,044		185,424
Swap assets	1,265		12,437
Prepaid assets	5,306		6,369
WM&T fees receivable	4,880		4,523
Mortgage servicing rights	10,706	$ 10,817	11,333	$ 12,197	$ 12,544	$ 13,082
Other real estate owned	10		10
Other	18,173		17,113
Total other assets	$ 306,782		$ 308,750