Note 11 - Retirement Plans (Details) - Net Periodic Benefit Cost - Supplemental Retirement Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Note 11 - Retirement Plans (Details) - Net Periodic Benefit Cost [Line Items]
Service cost	$ 15	$ 12
Interest cost	19	22
Recognized net actuarial gain	0	(4)
Net periodic benefit cost	$ 34	$ 30
Major assumptions:
Discount rate used to determine net period benefit cost	3.22%	4.06%
Discount rate used to determine benefit obligation at year end	3.39%	3.22%