Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Restricted Stock Units (RSUs)	Common Stock	Common Stock Restricted Stock Units (RSUs)	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non- Controlling Interests
Beginning Balance (in Shares) at Dec. 31, 2014			37,360,515
Beginning Balance at Dec. 31, 2014	$ 645,085		$ 374		$ 217,289	$ 433,641	$ (24,669)	$ 18,450
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (7,990)					(8,067)		77
Issuance of common stock upon stock option exercises, including tax benefit (in shares)	209,205		209,205
Issuance of common stock upon stock option exercises, including tax benefit	$ 2,466		$ 2		2,464
Restricted shares issued (in Shares)				12,646
Issuance of shares pursuant to deferred stock unit awards (in Shares)			27,779
Forfeitures of restricted shares (in Shares)			(54,045)
Forfeitures of restricted shares	(1)		$ (1)
Shares repurchased and retired (in Shares)			(1,502,601)
Shares repurchased and retired	(27,803)		$ (14)		(27,789)
Equity-based compensation expense	7,987				7,987
Investment by non-controlling interests	239							239
Purchase of non-controlling interests	472							472
Currency translation adjustment and derivative transactions, net	(24,955)						(23,192)	(1,763)
Ending Balance (in Shares) at Dec. 31, 2015			36,053,499
Ending Balance at Dec. 31, 2015	594,556		$ 361		199,951	425,574	(47,861)	16,531
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 29,160					29,488		(328)
Issuance of common stock upon stock option exercises, including tax benefit (in shares)	114,307		114,307
Issuance of common stock upon stock option exercises, including tax benefit	$ 1,818		$ 1		1,817
Restricted shares issued (in Shares)				141,507
Restricted shares issued		$ 1		$ 1
Issuance of shares pursuant to deferred stock unit awards (in Shares)			39,660
Forfeitures of restricted shares (in Shares)			(42,775)
Shares repurchased and retired (in Shares)			(2,349,894)
Shares repurchased and retired	(44,454)		$ (23)		(44,431)
Equity-based compensation expense	9,261				9,261
Sale of non-controlling interest	(7,278)							(7,278)
Distributions to non-controlling interests	(1,276)							(1,276)
Currency translation adjustment and derivative transactions, net	$ (5,605)						(5,639)	34
Ending Balance (in Shares) at Dec. 31, 2016	33,956,304		33,956,304
Ending Balance at Dec. 31, 2016	$ 576,183		$ 340		166,598	455,062	(53,500)	7,683
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (66,235)					(69,054)		2,819
Issuance of common stock upon stock option exercises, including tax benefit (in shares)	43,573		43,573
Issuance of common stock upon stock option exercises, including tax benefit	$ 822				822
Restricted shares issued (in Shares)				95,510
Restricted shares issued		$ 1		$ 1
Issuance of shares pursuant to performance units (in Shares)			49,672
Issuance of shares pursuant to deferred stock unit awards (in Shares)			30,559
Forfeitures of restricted shares (in Shares)			(1,084)
Shares repurchased and retired (in Shares)			(1,711,992)
Shares repurchased and retired	(37,849)		$ (16)		(37,833)
Equity-based compensation expense	11,162				11,162
Investment by non-controlling interests	158							158
Distributions to non-controlling interests	(71)							(71)
Currency translation adjustment and derivative transactions, net	$ 20,885						20,664	221
Ending Balance (in Shares) at Dec. 31, 2017	32,462,542		32,462,542
Ending Balance at Dec. 31, 2017	$ 505,056		$ 325		$ 140,749	$ 386,008	$ (32,836)	$ 10,810