Consolidated Statement of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Stockholders' Equity of the Company Preferred Stock [Member]	Stockholders' Equity of the Company Common Stock [Member]	Stockholders' Equity of the Company Treasury Stock [Member]	Stockholders' Equity of the Company Additional Paid-in Capital [Member]	Stockholders' Equity of the Company Accumulated Other Comprehensive Income [Member]	Stockholders' Equity of the Company Retained Earnings [Member]	Noncontrolling Interest [Member]
Beginning balance,value at Dec. 31, 2012	$ 500,337	$ 0	$ 522	$ (428,716)	$ 350,714	$ 22,981	$ 540,791	$ 14,045
Preferred stock beginning balance, share at Dec. 31, 2012	0	0
Common stock beginning balance, share at Dec. 31, 2012	52,288,567		52,288,000
Net income	50,494						47,919	2,575
Dividends distributed to noncontrolling interest	(3,420)							(3,420)
Purchases of outstanding noncontrolling interest	(425)				3,715			(4,140)
Deconsolidation of a subsidiary	(121)							(121)
Foreign currency translation adjustments	(18,191)					(18,087)		(104)
Derivatives valuation, net of tax	(13,231)					(13,231)
Vesting of restricted stock units, share			400,000
Vesting of restricted stock units, value	(4,145)		4	5,717	(9,866)
Exercise of stock options, share			90,000
Exercise of stock options, value	856		1	1,285	(430)
Excess tax benefit from equity-based awards	644				644
Equity-based compensation expense	9,749				9,724			25
Purchases of common stock, share			(2,281,000)
Purchases of common stock, value	(51,627)		(23)	(51,604)
Other	451					451
Ending balance,value at Sep. 30, 2013	$ 471,371	$ 0	$ 504	$ (473,318)	$ 354,501	$ (7,886)	$ 588,710	$ 8,860
Preferred stock ending balance, share at Sep. 30, 2013	0	0
Common stock ending balance, share at Sep. 30, 2013	50,496,816		50,497,000