Note 8 - Fair Values - Losses Resulting From Non-recurring Fair Value Adjustments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Losses resulting from nonrecurring fair value adjustments	$ 66	$ 76	$ 162	$ 153
Collateral Dependent Impaired Loans [Member]
Losses resulting from nonrecurring fair value adjustments		20		20
Other Real Estate Owned [Member]
Losses resulting from nonrecurring fair value adjustments	$ 66	$ 56	$ 162	$ 133