Consolidated Statements of Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Non- Controlling Interests
Balance (in shares) at Dec. 31, 2015		36,053,499
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)	11,031			11,697		(666)
Issuance of common stock upon stock option exercises (in shares)		18,193
Issuance of common stock upon stock option exercises, including tax benefit	(10)		(10)
Issuance of shares pursuant to restricted stock units (in shares)		14,034
Issuance of shares pursuant to deferred stock unit awards (in shares)		39,660
Forfeitures of restricted shares (in shares)		(18,499)
Shares repurchased and retired (in shares)		(1,967,347)
Shares repurchased and retired	(36,597)	$ (20)	(36,577)
Equity-based compensation expense	7,689		7,689
Sale of non-controlling interest, non-controlling interests	7,278					7,278
Distributions to non-controlling interests	(1,276)					(1,276)
Currency translation adjustment and derivative transactions, net	(318)				(391)	73
Balance (in shares) at Sep. 30, 2016		34,139,540
Balance at Sep. 30, 2016	$ 567,797	$ 341	171,053	437,271	(48,252)	7,384
Balance (in shares) at Dec. 31, 2016	33,956,304	33,956,304
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)	(53,851)			(56,265)		2,414
Issuance of shares pursuant to restricted stock units (in shares)		90,663
Issuance of shares pursuant to deferred stock unit awards (in shares)		30,559
Issuance of shares pursuant to restricted stock units	1	$ 1
Issuance of shares pursuant to performance units (in shares)		49,672
Forfeitures of restricted shares (in shares)		(1,084)
Shares repurchased and retired (in shares)		(1,452,296)
Shares repurchased and retired	(31,730)	$ (14)	(31,716)
Equity-based compensation expense	9,206		9,206
Investments from non-controlling interests	158					158
Distributions to non-controlling interests	(71)					(71)
Currency translation adjustment and derivative transactions, net	$ 16,428				16,342	86
Balance (in shares) at Sep. 30, 2017	32,673,818	32,673,818
Balance at Sep. 30, 2017	$ 516,324	$ 327	$ 144,088	$ 398,797	$ (37,158)	$ 10,270