Note 5 - Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Amortized cost, Due in one year or less, available for sale securities	$ 7,518
Fair value, Due in one year or less, available for sale securities	7,539
Amortized cost, Due after one year through five years, available for sale securities	174,169
Fair value, Due after one year through five years, available for sale securities	174,317
Amortized cost, Due after give years through ten years, available for sale securities	51,036
Fair value, Due after give years through ten years, available for sale securities	51,350
Amortized cost, Due after ten years, available for sale securities	68,283
Fair value, Due after ten years, available for sale securities	69,895
Amortized cost, No maturity, available for sale securities	189
Fair value, No maturity, available for sale securities	141
Amortized cost, Total securities available for sale	301,195
Securities available for sale	303,242	$ 236,131
Amortized cost, Due in one year or less, held to maturity securities	2,148
Fair value, Due in one year or less, held to maturity securities	2,188
Amortized cost, Due after one year through five years, held to maturity securities	20,798
Fair value, Due after one year through five years, held to maturity securities	22,207
Amortized cost, Due after give years through ten years, held to maturity securities	17,362
Fair value, Due after give years through ten years, held to maturity securities	18,415
Amortized cost, Due after ten years, held to maturity securities	98,116
Fair value, Due after ten years, held to maturity securities	103,431
Amortized cost, Total securities held to maturity	138,424	152,028
Fair value, Total securities held to maturity	$ 146,241	$ 158,032