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 (Loss) [Member]	Stockholders' Equity of the Company Retained Earnings [Member]	Noncontrolling Interest [Member]
Beginning balance,value at Dec. 31, 2011	$ 470,247	$ 0	$ 566	$ (357,267)	$ 350,386	$ (5,474)	$ 470,776	$ 11,260
Preferred stock beginning balance, share at Dec. 31, 2011	0	0
Common stock beginning balance, share at Dec. 31, 2011	56,635,319		56,635,000
Net income	52,785						49,633	3,152
Acquisition of noncontrolling interest	941							941
Dividends distributed to noncontrolling interest	(1,440)							(1,440)
Foreign currency translation adjustment	10,607					10,494		113
Derivatives valuation, net of tax	13,170					13,170
Vesting of restricted stock units, share			485,000
Vesting of restricted stock units, value	(4,032)		5	6,765	(10,802)
Exercise of stock options, share			98,000
Exercise of stock options, value	1,135		1	1,371	(237)
Excess tax benefit from equity-based awards	(472)				(472)
Equity-based compensation expense	10,256				10,256
Purchases of common stock, share			(3,506,000)
Purchases of common stock, value	(55,211)		(35)	(55,176)
Other	933					933
Ending balance,value at Sep. 30, 2012	$ 498,919	$ 0	$ 537	$ (404,307)	$ 349,131	$ 19,123	$ 520,409	$ 14,026
Preferred stock ending balance, share at Sep. 30, 2012	0	0
Common stock ending balance, share at Sep. 30, 2012	53,712,342		53,712,000