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, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Generated tax credits	$ 120	$ 158	$ 239	$ 316
Tax benefits from taxable losses	26	45	52	90
Raymond James California Housing Opportunities Fund II [Member]
Generated tax credits	43	44	85	88
Tax benefits from taxable losses	8	12	15	24
WNC Institutional Tax Credit Fun 38 L.P. [Member]
Generated tax credits	28	28	56	57
Tax benefits from taxable losses	4	7	7	13
Merritt Community Capital Corporation Fund XV, L.P. [Member]
Generated tax credits	48	54	96	108
Tax benefits from taxable losses	8	14	17	28
California Affordable Housing Fund [Member]
Generated tax credits	1	32	2	63
Tax benefits from taxable losses	$ 6	$ 12	$ 13	$ 25