Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Non- Controlling Interests	Restricted Stock Units	Restricted Stock Units Common Stock	Performance Units	Performance Units Common Stock
Balance (in shares) at Dec. 31, 2017		32,462,542
Balance at Dec. 31, 2017	$ 505,056	$ 325	$ 140,749	$ 376,694	$ (23,522)	$ 10,810
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,476)			(2,069)		593
Issuance of shares pursuant to restricted/performance stock units (in shares)								275,384		296,909
Issuance of shares pursuant to restricted/performance stock units							$ 3	$ 3	$ 3	$ 3
Issuance of shares pursuant to deferred stock unit awards (in shares)		4,568
Issuance of shares pursuant to deferred stock unit awards	0
Shares repurchased and retired (in shares)		(571,580)
Shares repurchased and retired	(13,676)	$ (6)	(13,670)
Equity-based compensation expense	2,158		2,158
Currency translation adjustments, derivative transactions and pension activity, net	2,715				2,662	53
Balance (in shares) at Mar. 31, 2018		32,467,823
Balance at Mar. 31, 2018	$ 495,051	$ 325	129,237	374,893	(20,860)	11,456
Balance (in shares) at Dec. 31, 2018	31,922,409	31,922,409
Balance at Dec. 31, 2018	$ 470,187	$ 319	122,818	379,890	(40,290)	7,450
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(3,991)			(4,001)		10
Issuance of common stock upon stock option exercises, including tax benefit (in shares)		52,783
Issuance of common stock upon stock option exercises, including tax benefit	956	$ 1	955
Issuance of shares pursuant to restricted/performance stock units (in shares)								171,575		110,656
Issuance of shares pursuant to restricted/performance stock units							$ 2	$ 2	$ 1	$ 1
Issuance of shares pursuant to deferred stock unit awards (in shares)		9,438
Issuance of shares pursuant to deferred stock unit awards	0
Shares repurchased and retired (in shares)		(774,989)
Shares repurchased and retired	(14,191)	$ (8)	(14,183)
Equity-based compensation expense	2,007		2,007
Distributions to non-controlling interests	(96)					(96)
Currency translation adjustments, derivative transactions and pension activity, net	$ (305)				(218)	(87)
Balance (in shares) at Mar. 31, 2019	31,491,872	31,491,872
Balance at Mar. 31, 2019	$ 454,570	$ 315	$ 111,597	$ 375,889	$ (40,508)	$ 7,277