Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	Restricted Stock [Member]	Restricted Stock [Member] Common Stock [Member]	Restricted Stock Units [Member] Common Stock [Member]
Balance at Dec. 31, 2013	$ 726,921	$ 380	$ 236,128	$ 470,808	$ 2,052	$ 17,553
Balance (in Shares) at Dec. 31, 2013		37,983,114
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	609			(271)		880
Issuance of common stock upon stock option exercises	8,211	$ 5	8,206
Issuance of common stock upon stock option exercises (in Shares)		526,359
Restricted shares issued							$ 2	$ 2
Restricted shares issued (in Shares)								226,483	15,277
Issuance of shares pursuant to deferred stock unit awards (in Shares)		31,794
Forfeitures of restricted shares	(1)	$ (1)
Forfeitures of restricted shares (in Shares)		(75,006)
Shares repurchased and retired	(31,063)	$ (12)	(31,051)
Shares repurchased and retired (in Shares)		(1,333,690)
Equity-based compensation expense	4,201		4,201
Purchase of non-controlling interest	(617)		(909)			292
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	0
Currency translation adjustment and derivative transactions, net	(16,835)				(16,263)	(572)
Balance at Sep. 30, 2014	691,428	$ 374	216,575	470,537	(14,211)	18,153
Balance (in Shares) at Sep. 30, 2014		37,374,331
Balance at Dec. 31, 2014	$ 645,085	$ 374	217,289	433,641	(24,669)	18,450
Balance (in Shares) at Dec. 31, 2014	37,360,515	37,360,515
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 25,443			24,793		650
Issuance of common stock upon stock option exercises	$ 1,092	$ 1	1,091
Issuance of common stock upon stock option exercises (in Shares)	109,344	109,344
Restricted shares issued (in Shares)									12,326
Issuance of shares pursuant to deferred stock unit awards (in Shares)		27,779
Forfeitures of restricted shares	$ (1)	$ (1)
Forfeitures of restricted shares (in Shares)		(50,552)
Shares repurchased and retired	(21,941)	$ (12)	(21,929)
Shares repurchased and retired (in Shares)		(1,212,181)
Equity-based compensation expense	6,847		6,847
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(472)					472
Currency translation adjustment and derivative transactions, net	(21,316)				(19,875)	(1,441)
Balance at Sep. 30, 2015	$ 634,737	$ 362	$ 203,298	$ 458,434	$ (44,544)	$ 17,187
Balance (in Shares) at Sep. 30, 2015	36,227,841	36,247,231