Note 7 - Fair Value Measurements - Fair Value of Financial Assets and Liabilities Measure on Non-recurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Loans held for sale	$ 592	$ 1,587
Other real estate owned	3,625	3,249
Fair Value, Inputs, Level 2 [Member]
Loans held for sale	592	1,587
Other real estate owned
Fair Value, Inputs, Level 3 [Member]
Loans held for sale
Other real estate owned	$ 3,625	$ 3,249