Note 18 - Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale Securities	$ 188,476	$ 198,585
Fair Value, Inputs, Level 1 [Member]
Available-for-sale Securities	0	0
Fair Value, Inputs, Level 2 [Member]
Available-for-sale Securities	188,476	198,585
Fair Value, Inputs, Level 3 [Member]
Available-for-sale Securities	0	0
US Treasury and Government [Member]
Available-for-sale Securities	5,631	49,500
US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale Securities	0	0
US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale Securities	5,631	49,500
US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale Securities	0	0
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale Securities	87,050	63,933
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale Securities	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale Securities	87,050	63,933
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale Securities	0	0
Collateralized Mortgage Backed Securities [Member]
Available-for-sale Securities	95,795	85,152
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale Securities	0	0
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale Securities	95,795	85,152
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale Securities	$ 0	$ 0