Consolidated Statement of Stockholders' Equity (USD $)	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	$ 470,247,000	$ 0	$ 566,000	$ (357,267,000)	$ 350,386,000	$ (5,474,000)	$ 470,776,000	$ 11,260,000
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	23,065,000						21,204,000	1,861,000
Acquisition of noncontrolling interest	941,000							941,000
Dividends distributed to noncontrolling interest	(720,000)							(720,000)
Foreign currency translation adjustments	3,252,000					3,205,000		47,000
Derivatives valuation, net of tax	8,816,000					8,816,000
Vesting of restricted stock units issued out of treasury, share			475,000
Vesting of restricted stock units issued out of treasury, value	(3,824,000)		5,000	6,626,000	(10,455,000)
Exercise of stock options, share			63,000
Exercise of stock options, value	770,000		1,000	879,000	(110,000)
Excess tax benefit from equity-based awards	(648,000)				(648,000)
Equity-based compensation expense	6,845,000				6,845,000
Purchases of common stock, share			(2,618,000)
Purchases of common stock, value	(40,732,000)		(26,000)	(40,706,000)
Other	650,000					650,000
Ending balance,value at Jun. 30, 2012	$ 468,662,000	$ 0	$ 546,000	$ (390,468,000)	$ 346,018,000	$ 7,197,000	$ 491,980,000	$ 13,389,000
Preferred stock ending balance, share at Jun. 30, 2012	0	0
Common stock ending balance, share at Jun. 30, 2012	54,555,105		54,555,000