Note 8 - Fair Values - Losses Resulting From Non-recurring Fair Value Adjustments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Losses resulting from nonrecurring fair value adjustments		$ 78	$ 138	$ 98
Collateral Dependent Impaired Loans [Member]
Losses resulting from nonrecurring fair value adjustments		43		63
Other Real Estate Owned [Member]
Losses resulting from nonrecurring fair value adjustments		$ 35	$ 138	$ 35