Consolidated Statements of Equity (Unaudited) (USD $) In Thousands, except Share data	Restricted Stock [Member] Common Stock [Member] USD ($)	Restricted Stock [Member] USD ($)	Restricted Stock Units (RSUs) [Member] Common Stock [Member]	Common Stock [Member] USD ($)	Additional Paid-in Capital [Member] USD ($)	Retained Earnings [Member] USD ($)	Accumulated Other Comprehensive Income (Loss) [Member] USD ($)	Noncontrolling Interest [Member] USD ($)	Total USD ($)
Balance at Dec. 31, 2010				$ 392	$ 251,578	$ 347,249	$ 18,113	$ 9,375	$ 626,707
Balance (in Shares) at Dec. 31, 2010				39,246,015
Net income (loss)						11,795		(79)	11,716
Issuance of common stock upon stock option exercises including tax benefit				1	3,551				3,552
Issuance of common stock upon stock option exercises including tax benefit (in Shares)				128,052
Restricted shares issued				2					2
Restricted shares issued (in Shares)				166,276
New shares issued				2	3,998				4,000
New shares issued (in Shares)				246,760
Issuance of shares pursuant to deferred stock unit awards (in Shares)				20,640
Forfeitures of restricted shares (in Shares)				(69,265)
Equity-based compensation expense					5,494				5,494
Investment by non-controlling interests								301	301
Distribution to non-controlling interests								(2,006)	(2,006)
Currency translation adjustment and derivative transactions							(13,870)	383	(13,487)
Balance at Sep. 30, 2011				397	264,621	359,044	4,243	7,974	636,279
Balance (in Shares) at Sep. 30, 2011				39,738,478
Balance at Dec. 31, 2011				394	260,680	373,796	5,862	8,257	648,989
Balance (in Shares) at Dec. 31, 2011				39,352,375
Net income (loss)						37,766		2,057	39,823
Issuance of common stock upon stock option exercises including tax benefit				1	562				563
Issuance of common stock upon stock option exercises including tax benefit (in Shares)				26,776					26,776
Restricted shares issued	3	3
Restricted shares issued (in Shares)	266,715		14,446
Issuance of shares pursuant to deferred stock unit awards (in Shares)				34,132
Forfeitures of restricted shares (in Shares)				(30,599)
Repurchase of common stock				(5)	(6,349)				(6,354)
Repurchase of common stock (in Shares)				(384,890)
Equity-based compensation expense					5,246				5,246
Investment by non-controlling interests								4,939	4,939
Currency translation adjustment and derivative transactions							3,866	336	4,202
Balance at Sep. 30, 2012				$ 393	$ 260,139	$ 411,562	$ 9,728	$ 15,589	$ 697,411
Balance (in Shares) at Sep. 30, 2012				39,278,955