Note 7 - Fair Value Measurement - Fair Value of Financial Assets and Liabilities Measure on Non-recurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Loans held for sale	$ 280	$ 1,587
Other real estate owned	3,414	3,249
Fair Value, Inputs, Level 2 [Member]
Loans held for sale	280	1,587
Other real estate owned	697	697
Fair Value, Inputs, Level 3 [Member]
Loans held for sale
Other real estate owned	$ 2,717	$ 2,717