Note 7 - Fair Value of Financial Instruments - Assets and Liabilities Measured On a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Securities available for sale	$ 186,149	$ 198,342
Fair Value, Inputs, Level 1 [Member]
Securities available for sale
Fair Value, Inputs, Level 2 [Member]
Securities available for sale	186,149	198,342
Fair Value, Inputs, Level 3 [Member]
Securities available for sale
US Government Agencies Debt Securities [Member]
Securities available for sale	9,031	7,566
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	9,031	7,566
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale
Corporate Debt Securities [Member]
Securities available for sale	13,085	11,127
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	13,085	11,127
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale
Collateralized Mortgage Backed Securities [Member]
Securities available for sale	85,219	99,372
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	85,219	99,372
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale	78,123	79,636
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	78,123	79,636
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale
Other Debt Obligations [Member]
Securities available for sale	691	641
Other Debt Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available for sale
Other Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available for sale	691	641
Other Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available for sale