Note 18 - Income Taxes - Income From Continuing Operations Before Income Taxes and Equity in Income (Losses) of Investees (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S.									$ 13,680	$ (7,109)	$ (236)
Non-U.S. (foreign)									157,050	148,197	113,835
Income from continuing operations before income taxes and equity in losses of investees	$ 40,025	$ 33,446	$ 45,039	$ 52,220	$ 36,683	$ 29,047	$ 33,967	$ 41,391	$ 170,730	$ 141,088	$ 113,599