CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Common Stock in Treasury
Beginning Balance (in shares) at Dec. 31, 2017		16,796,884
Beginning Balance at Dec. 31, 2017	$ 352,066	$ 18	$ 223,055	$ 168,624	$ (7,822)	$ (31,809)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	455			455
Currency translation adjustment	5,214				5,214
Stock-based compensation	1,553		1,553
Common stock issued, net of shares withheld for employee taxes (in shares)		158,795
Common stock issued, net of shares withheld for employee taxes	6,676		6,601			75
Ending Balance (in shares) at Mar. 31, 2018		16,955,679
Ending Balance at Mar. 31, 2018	368,329	$ 18	231,209	171,444	(2,608)	(31,734)
Beginning Balance (in shares) at Dec. 31, 2017		16,796,884
Beginning Balance at Dec. 31, 2017	352,066	$ 18	223,055	168,624	(7,822)	(31,809)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(828)
Currency translation adjustment	(9,074)
Ending Balance (in shares) at Sep. 30, 2018		17,252,160
Ending Balance at Sep. 30, 2018	370,959	$ 19	249,284	170,161	(16,896)	(31,609)
Beginning Balance (in shares) at Mar. 31, 2018		16,955,679
Beginning Balance at Mar. 31, 2018	368,329	$ 18	231,209	171,444	(2,608)	(31,734)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,205			1,205
Currency translation adjustment	(9,377)				(9,377)
Stock-based compensation	1,847		1,847
Common stock issued, net of shares withheld for employee taxes (in shares)		23,079
Common stock issued, net of shares withheld for employee taxes	699		699
Ending Balance (in shares) at Jun. 30, 2018		16,978,758
Ending Balance at Jun. 30, 2018	362,703	$ 18	233,755	172,649	(11,985)	(31,734)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(2,488)			(2,488)
Currency translation adjustment	(4,911)				(4,911)
Stock-based compensation	2,317		2,317
Common stock issued, net of shares withheld for employee taxes (in shares)		273,402
Common stock issued, net of shares withheld for employee taxes	13,338	$ 1	13,212			125
Ending Balance (in shares) at Sep. 30, 2018		17,252,160
Ending Balance at Sep. 30, 2018	370,959	$ 19	249,284	170,161	(16,896)	(31,609)
Beginning Balance (in shares) at Dec. 31, 2018		17,253,011
Beginning Balance at Dec. 31, 2018	376,609	$ 19	251,329	175,353	(18,483)	(31,609)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	152			152
Currency translation adjustment	(1,564)				(1,564)
Stock-based compensation	2,564		2,564
Common stock issued, net of shares withheld for employee taxes (in shares)		64,864
Common stock issued, net of shares withheld for employee taxes	$ (846)		(1,053)			207
Ending Balance (in shares) at Mar. 31, 2019	17,253,011	17,317,875
Ending Balance at Mar. 31, 2019	$ 376,588	$ 19	252,840	175,178	(20,047)	(31,402)
Beginning Balance (in shares) at Dec. 31, 2018		17,253,011
Beginning Balance at Dec. 31, 2018	376,609	$ 19	251,329	175,353	(18,483)	(31,609)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(12,452)
Currency translation adjustment	$ (5,947)
Ending Balance (in shares) at Sep. 30, 2019	17,404,087	17,404,087
Ending Balance at Sep. 30, 2019	$ 367,525	$ 19	260,737	162,574	(24,430)	(31,375)
Beginning Balance (in shares) at Mar. 31, 2019	17,253,011	17,317,875
Beginning Balance at Mar. 31, 2019	$ 376,588	$ 19	252,840	175,178	(20,047)	(31,402)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(6,405)			(6,405)
Currency translation adjustment	1,263				1,263
Stock-based compensation	2,752		2,752
Common stock issued, net of shares withheld for employee taxes (in shares)		21,187
Common stock issued, net of shares withheld for employee taxes	141		114			27
Ending Balance (in shares) at Jun. 30, 2019		17,339,062
Ending Balance at Jun. 30, 2019	374,339	$ 19	255,706	168,773	(18,784)	(31,375)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(6,199)			(6,199)
Currency translation adjustment	(5,646)				(5,646)
Stock-based compensation	3,387		3,387
Common stock issued, net of shares withheld for employee taxes (in shares)		65,025
Common stock issued, net of shares withheld for employee taxes	$ 1,644		1,644
Ending Balance (in shares) at Sep. 30, 2019	17,404,087	17,404,087
Ending Balance at Sep. 30, 2019	$ 367,525	$ 19	$ 260,737	$ 162,574	$ (24,430)	$ (31,375)