Note 8 - Other Assets - Summary of Major Components of Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash surrender value of life insurance other than BOLI	$ 16,145	$ 15,029
Net deferred tax asset	14,466	10,193
Investments in tax credit related ventures	6,248	4,537
Prepaid assets	2,812	3,072
Trust fee receivable	2,171	1,939
Mortgage servicing rights	1,372	1,022	$ 875	$ 921
Other real estate owned	493	1,018
Other	7,232	8,362
Total other assets	$ 50,939	$ 45,172