Note 7 - Fair Value of Financial Instruments - Summary of Financial Assets Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets, Fair Value Disclosure, Nonrecurring Basis	$ 12,170	$ 14,061
Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis
Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis	12,170	14,061
Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis
Impaired Loans [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis	10,943	12,865
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis	10,943	12,865
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis
Repossessed Assets [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis	1,227	1,196
Repossessed Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis
Repossessed Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis	1,227	1,196
Repossessed Assets [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure, Nonrecurring Basis