Note 9 - Disclosures About Fair Value of Assets and Liabilities - Fair Value of Assets Measured on Non-recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Impaired Loans [Member]
Assets measured at fair value on a nonrecurring basis	$ 1,474	$ 1,006
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value on a nonrecurring basis
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value on a nonrecurring basis
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets measured at fair value on a nonrecurring basis	1,474	1,006
Foreclosed Assets Held For Sale [Member]
Assets measured at fair value on a nonrecurring basis		149
Foreclosed Assets Held For Sale [Member] | Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value on a nonrecurring basis
Foreclosed Assets Held For Sale [Member] | Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value on a nonrecurring basis
Foreclosed Assets Held For Sale [Member] | Fair Value, Inputs, Level 3 [Member]
Assets measured at fair value on a nonrecurring basis		$ 149