Note 10 - Accrued Pension Liabilities (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Plan Assets, Amount, Ending Balance	$ 0
Defined Benefit Plan Corridor Percentage	10.00%
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	$ 29	$ 24	$ (117)