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)						10,635		(235)	10,400
Issuance of common stock upon stock option exercises including tax benefit				1	3,303				3,304
Issuance of common stock upon stock option exercises including tax benefit (in Shares)				119,559
Restricted shares issued				2					2
Restricted shares issued (in Shares)				166,276
Issuance of shares pursuant to deferred stock unit awards (in Shares)				5,681
Forfeitures of restricted stock (in Shares)				(67,461)
Equity-based compensation expense					4,007				4,007
Investment by non-controlling interests								141	141
Distribution to non-controlling interests								(1,729)	(1,729)
Currency translation adjustment and derivative transactions							5,410	1,055	6,465
Balance at Jun. 30, 2011				395	258,888	357,884	23,523	8,607	649,297
Balance (in Shares) at Jun. 30, 2011				39,470,070
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)						18,222		865	19,087
Issuance of common stock upon stock option exercises including tax benefit				1	619				620
Issuance of common stock upon stock option exercises including tax benefit (in Shares)				25,123
Restricted shares issued	3	3
Restricted shares issued (in Shares)	266,715		11,936
Issuance of shares pursuant to deferred stock unit awards (in Shares)				22,185
Forfeitures of restricted stock (in Shares)				(18,861)
Repurchase of common stock				(5)	(6,259)				(6,264)
Repurchase of common stock (in Shares)				(379,674)
Equity-based compensation expense					4,010				4,010
Investment by non-controlling interests								4,939	4,939
Currency translation adjustment and derivative transactions							(407)	(5)	(412)
Balance at Jun. 30, 2012				$ 393	$ 259,050	$ 392,018	$ 5,455	$ 14,056	$ 670,972
Balance (in Shares) at Jun. 30, 2012				39,279,799