CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (USD $) In Thousands	Total	Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income [Member]	Treasury stock [Member]	Noncontrolling interest [Member]
Beginning Balance at Dec. 31, 2012		$ 31	$ 54,679	$ 349,672	$ 12,498	$ (35,404)	$ 118,505
Net income	57,366			43,365			14,001
Shares issued upon exercise of stock options			1,319
Shares received as proceeds of option exercises
Foreign currency translation adjustment	10,033				7,089		2,944
Net derivative instrument loss, net of tax					(240)		(87)
Sale of subsidiary shares to noncontrolling interests
Dividends				(11,074)			(8,341)
Stock-based compensation			367	124			45
Ending Balance at Sep. 30, 2013	549,493		56,365	382,087	19,347	(35,404)	127,067
Beginning Balance at Dec. 31, 2013	535,356	31	57,877	359,459	25,860	(36,016)	128,145
Net income	33,580			26,115			7,465
Shares issued upon exercise of stock options			1,074			101
Shares received as proceeds of option exercises						(351)
Foreign currency translation adjustment	(42,620)				(30,324)		(12,296)
Net derivative instrument loss, net of tax
Sale of subsidiary shares to noncontrolling interests			(335)				1,365
Dividends				(11,137)			(4,667)
Stock-based compensation			507	79			30
Ending Balance at Sep. 30, 2014	$ 512,982		$ 59,123	$ 374,516	$ (4,464)	$ (36,266)	$ 120,042