Note 9 - Business Segments - Reconciling Information Between Reportable Segments and Consolidated Totals (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Total Segment Revenues [Member]
Revenues:
Revenue	$ 151,594	$ 120,231
Intersegment Eliminations [Member]
Revenues:
Revenue	1,941	19,757
Consolidation, Eliminations [Member]
Revenues:
Revenue	(1,941)	(19,757)
Revenue	151,594	120,231
Operating income:
Operating income	50,543	29,851
Interest income	320	9
Interest expense, net	(16,023)	(17,828)
Foreign currency translation and transaction gains (losses)	1,962	(1,366)
Income attributable to sale of tax benefits	4,398	5,552
Other non-operating income (expense), net	191	283
Total consolidated income before income taxes and equity in income of investees	$ 41,391	$ 16,501