Note 9 - Defined Benefit Retirement Plan (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)
Defined Benefit Plan, Number of Employees Covered			3
Defined Benefit Plan, Number of Present Employees Covered			2
Defined Benefit Plan, Number of Retired Employees Covered			1
Deferred Compensation Arrangement with Individual, Requisite Service Period			25 years
Defined Benefit Plan, Number of Current Officers Fully Vested			1
Defined Benefit Plan, Number of Current Officers That Will Be Fully Vested in Year 2017			1
Defined Benefit Plan, Net Periodic Benefit Cost	$ 34	$ 36	$ 67	$ 71