Note 5 - Qualified Affordable Housing Partnership Investments - Generated Tax Credits and Benefits From Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Generated tax credits	$ 125	$ 114	$ 248	$ 227
Tax benefits from taxable losses	30	25	60	51
Raymond James California Housing Opportunities Fund II [Member]
Generated tax credits	43	43	85	85
Tax benefits from taxable losses	7	7	14	15
WNC Institutional Tax Credit Fun 38 L.P. [Member]
Generated tax credits	22	23	44	46
Tax benefits from taxable losses	4	4	8	8
Merritt Community Capital Corporation Fund XV, L.P. [Member]
Generated tax credits	48	48	96	96
Tax benefits from taxable losses	8	8	16	16
California Affordable Housing Fund [Member]
Generated tax credits	1	0	1	0
Tax benefits from taxable losses	6	6	11	12
Boston Capital [Member]
Generated tax credits	11	0	22	0
Tax benefits from taxable losses	$ 5	$ 0	$ 11	$ 0