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, 2013	$ 473,482	$ 0	$ 503	$ (477,399)	$ 356,381	$ (20,586)	$ 606,502	$ 8,081
Preferred stock beginning balance, share at Dec. 31, 2013	0	0
Common stock beginning balance, share at Dec. 31, 2013	50,352,881		50,353
Net income	54,122						50,327
Net income excluding mandatorily redeemable noncontrolling interest	53,706							3,379
Dividends distributed to noncontrolling interest	(3,150)							(3,150)
Adjustments to redemption value of mandatorily redeemable noncontrolling interest	(1,109)						(1,109)
Foreign currency translation adjustments	(11,373)					(11,206)		(167)
Derivatives valuation, net of tax	(2,762)					(2,762)
Vesting of restricted stock units, value	(4,776)		4	5,203	(9,983)
Exercise of stock options, value	314		1	713	(400)
Excess tax benefit from equity-based awards	885				885
Equity-based compensation expense	8,953				8,941			12
Purchases of common stock, value	(47,281)		(19)	(47,262)
Other	804					804
Ending balance,value at Sep. 30, 2014	467,693	0	489	(518,745)	355,824	(33,750)	655,720	8,155
Preferred stock ending balance, share at Sep. 30, 2014	0	0
Common stock ending balance, share at Sep. 30, 2014	48,805,900		48,806
Beginning balance,value at Jun. 30, 2014
Net income	14,689
Foreign currency translation adjustments	(16,660)
Vesting of restricted stock units, share			346
Exercise of stock options, share			47
Purchases of common stock, share			(1,940)
Ending balance,value at Sep. 30, 2014	$ 467,693	$ 0	$ 489
Preferred stock ending balance, share at Sep. 30, 2014	0	0
Common stock ending balance, share at Sep. 30, 2014	48,805,900		48,806