Note 11 - Fair Values - Losses Resulting from Non-recurring Fair Value Adjustments (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Losses resulting from nonrecurring fair value adjustments	$ 78	$ 15	$ 98	$ 1,139
Collateral Dependent Impaired Loans [Member]
Losses resulting from nonrecurring fair value adjustments	43	15	63	1,068
Other Real Estate Owned [Member]
Losses resulting from nonrecurring fair value adjustments	$ 35		$ 35	$ 71

$ 78

$ 15

$ 98

$ 1,139

43

15

63

1,068

$ 35

$ 71