Consolidated Statements of Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (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	(3,949)			(3,792)		(157)
Issuance of common stock upon stock option exercises (in shares)		18,193
Issuance of common stock upon stock option exercises, including tax benefit	38		38
Issuance of shares pursuant to restricted stock units (in shares)		9,733
Forfeitures of restricted shares (in shares)		(14,528)
Shares repurchased and retired (in shares)		(910,656)
Shares repurchased and retired	(16,325)	$ (9)	(16,316)
Equity-based compensation expense	2,363		2,363
Sale of non-controlling interest	(7,278)					(7,278)
Currency translation adjustment and derivative transactions, net	(4,252)				(4,494)	242
Balance (in shares) at Mar. 31, 2016		35,156,241
Balance at Mar. 31, 2016	$ 565,153	$ 352	186,036	421,782	(52,355)	9,338
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	$ 7,753			5,871		1,882
Issuance of common stock upon stock option exercises (in shares)	0
Issuance of shares pursuant to restricted stock units (in shares)		62,279
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)		(462,317)
Shares repurchased and retired	(10,508)	$ (5)	(10,503)
Equity-based compensation expense	3,096		3,096
Currency translation adjustment and derivative transactions, net	$ 4,347				4,360	(13)
Balance (in shares) at Mar. 31, 2017	33,604,854	33,604,854
Balance at Mar. 31, 2017	$ 580,872	$ 336	$ 159,191	$ 460,933	$ (49,140)	$ 9,552