Note 6 - Property, Plant and Equipment (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Depreciation	$ 23,654	$ 21,196	$ 23,296
Payments To Acquire Property, Plant, and Equipment and Capital Expenditures Incurred But Not Yet Paid	51,604	57,400
Gain (Loss) on Disposition of Property Plant Equipment			1,234
Land [Member]
Gain (Loss) on Disposition of Property Plant Equipment			$ 1,234