Note 9 - Business Segments - Reconciling Information Between Reportable Segments and Consolidated Totals (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating Segments [Member]
Revenues:
Net revenue from external customers	$ 184,617	$ 162,852	$ 496,072	$ 423,570
Intersegment Eliminations [Member]
Revenues:
Net revenue from external customers	14,835	10,658	36,042	41,314
Consolidation, Eliminations [Member]
Revenues:
Net revenue from external customers	(14,835)	(10,658)	(36,042)	(41,314)
Net revenue from external customers	184,617	162,852	496,072	423,570
Operating income:
Operating income	48,223	46,479	150,653	114,973
Interest income	266	53	831	106
Interest expense, net	(17,137)	(17,748)	(51,561)	(54,435)
Derivatives and foreign currency transaction gains (losses)	(222)	1,296	(2,592)	(641)
Income attributable to sale of tax benefits	3,463	8,634	12,380	18,917
Other non-operating income (expense), net	(5,546)	(131)	(5,306)	(1,523)
Total consolidated income before income taxes and equity in income of investees	$ 29,047	$ 38,583	$ 104,405	$ 77,397