Note 11 - Fair Values - Fair Value of Assets Measured on a Non-recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets measured at fair value	$ 232,494	$ 175,174
Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value	232,494	175,174
Fair Value, Inputs, Level 3 [Member]
Assets measured at fair value
Fair Value, Measurements, Nonrecurring [Member]
Assets measured at fair value	852	1,806
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets measured at fair value	852	1,806
Fair Value, Measurements, Nonrecurring [Member] | Collateral Dependent Impaired Loans [Member]
Assets measured at fair value	830	1,587
Fair Value, Measurements, Nonrecurring [Member] | Collateral Dependent Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Fair Value, Measurements, Nonrecurring [Member] | Collateral Dependent Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Fair Value, Measurements, Nonrecurring [Member] | Collateral Dependent Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets measured at fair value	830	1,587
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned [Member]
Assets measured at fair value	22	219
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned [Member] | Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned [Member] | Fair Value, Inputs, Level 2 [Member]
Assets measured at fair value
Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate Owned [Member] | Fair Value, Inputs, Level 3 [Member]
Assets measured at fair value	$ 22	$ 219