Note 7 - Fair Value of Financial Instruments - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Securities Available for Sale, at Fair Values	$ 192,058	$ 198,342
Fair Value, Inputs, Level 1 [Member]
Securities Available for Sale, at Fair Values
Fair Value, Inputs, Level 2 [Member]
Securities Available for Sale, at Fair Values	192,058	198,342
Fair Value, Inputs, Level 3 [Member]
Securities Available for Sale, at Fair Values
US Government Agencies Debt Securities [Member]
Securities Available for Sale, at Fair Values	8,408	7,566
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities Available for Sale, at Fair Values
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities Available for Sale, at Fair Values	8,408	7,566
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities Available for Sale, at Fair Values
Corporate Debt Securities [Member]
Securities Available for Sale, at Fair Values	13,190	11,127
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities Available for Sale, at Fair Values
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities Available for Sale, at Fair Values	13,190	11,127
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities Available for Sale, at Fair Values
Collateralized Mortgage Backed Securities [Member]
Securities Available for Sale, at Fair Values	90,278	99,372
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities Available for Sale, at Fair Values
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities Available for Sale, at Fair Values	90,278	99,372
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities Available for Sale, at Fair Values
US States and Political Subdivisions Debt Securities [Member]
Securities Available for Sale, at Fair Values	79,509	79,636
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities Available for Sale, at Fair Values
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities Available for Sale, at Fair Values	79,509	79,636
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities Available for Sale, at Fair Values
Other Debt Obligations [Member]
Securities Available for Sale, at Fair Values	673	641
Other Debt Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Securities Available for Sale, at Fair Values
Other Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Securities Available for Sale, at Fair Values	673	641
Other Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Securities Available for Sale, at Fair Values