Note 5 - Qualified Affordable Housing Partnership Investments - Generated Tax Credits and Benefits From Investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Generated tax credits	$ 120	$ 157	$ 359	$ 473
Tax benefits from taxable losses	26	45	79	134
Raymond James California Housing Opportunities Fund II [Member]
Generated tax credits	43	44	127	132
Tax benefits from taxable losses	8	12	23	36
WNC Institutional Tax Credit Fun 38 L.P. [Member]
Generated tax credits	28	28	84	85
Tax benefits from taxable losses	4	6	11	19
Merritt Community Capital Corporation Fund XV, L.P. [Member]
Generated tax credits	48	54	144	162
Tax benefits from taxable losses	8	14	26	41
California Affordable Housing Fund [Member]
Generated tax credits	1	31	4	94
Tax benefits from taxable losses	$ 6	$ 13	$ 19	$ 38