Note 9 - Fair Values - Losses Resulting From Non-recurring Fair Value Adjustments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Losses resulting from nonrecurring fair value adjustments	$ 145	$ 425	$ 151	$ 467
Collateral Dependent Impaired Loans [Member]
Losses resulting from nonrecurring fair value adjustments	145	425	145	467
Other Real Estate Owned [Member]
Losses resulting from nonrecurring fair value adjustments	$ 0	$ 0	$ 6	$ 0