CONDENSED 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, 2019		17,576,618
Beginning balance at Dec. 31, 2019	$ 331,992	$ 19	$ 267,868	$ 112,879	$ (17,399)	$ (31,375)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(14,823)			(14,823)
Currency translation adjustment	(3,778)				(3,778)
Stock-based compensation	2,178		2,178
Common stock issued, net of shares withheld for employee taxes (in shares)		141,561
Common stock issued, net of shares withheld for employee taxes	1,221		894			327
Ending balance (in shares) at Mar. 31, 2020		17,718,179
Ending balance at Mar. 31, 2020	316,790	$ 19	270,940	98,056	(21,177)	(31,048)
Beginning balance (in shares) at Dec. 31, 2019		17,576,618
Beginning balance at Dec. 31, 2019	331,992	$ 19	267,868	112,879	(17,399)	(31,375)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(26,779)
Currency translation adjustment	(1,127)
Ending balance (in shares) at Sep. 30, 2020		17,832,934
Ending balance at Sep. 30, 2020	313,330	$ 19	276,779	86,100	(18,526)	(31,042)
Beginning balance (in shares) at Mar. 31, 2020		17,718,179
Beginning balance at Mar. 31, 2020	316,790	$ 19	270,940	98,056	(21,177)	(31,048)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(8,932)			(8,932)
Currency translation adjustment	(1,688)				(1,688)
Stock-based compensation	2,167		2,167
Common stock issued, net of shares withheld for employee taxes (in shares)		51,401
Common stock issued, net of shares withheld for employee taxes	224		218			6
Ending balance (in shares) at Jun. 30, 2020		17,769,580
Ending balance at Jun. 30, 2020	308,561	$ 19	273,325	89,124	(22,865)	(31,042)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(3,024)			(3,024)
Currency translation adjustment	4,339				4,339
Stock-based compensation	2,083		2,083
Common stock issued, net of shares withheld for employee taxes (in shares)		63,354
Common stock issued, net of shares withheld for employee taxes	1,371		1,371
Ending balance (in shares) at Sep. 30, 2020		17,832,934
Ending balance at Sep. 30, 2020	$ 313,330	$ 19	276,779	86,100	(18,526)	(31,042)
Beginning balance (in shares) at Dec. 31, 2020	17,990,707	17,990,707
Beginning balance at Dec. 31, 2020	$ 360,303	$ 19	287,979	113,508	(10,160)	(31,043)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(3,221)			(3,221)
Currency translation adjustment	(10,174)				(10,174)
Stock-based compensation	2,094		2,094
Common stock issued, net of shares withheld for employee taxes (in shares)		163,457
Common stock issued, net of shares withheld for employee taxes	1,781		1,530			251
Ending balance (in shares) at Mar. 31, 2021		18,154,164
Ending balance at Mar. 31, 2021	$ 350,783	$ 19	291,603	110,287	(20,334)	(30,792)
Beginning balance (in shares) at Dec. 31, 2020	17,990,707	17,990,707
Beginning balance at Dec. 31, 2020	$ 360,303	$ 19	287,979	113,508	(10,160)	(31,043)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(8,252)
Currency translation adjustment	$ (5,635)
Ending balance (in shares) at Sep. 30, 2021	19,384,350	18,202,416
Ending balance at Sep. 30, 2021	$ 356,771	$ 20	298,082	105,256	(15,795)	(30,792)
Beginning balance (in shares) at Mar. 31, 2021		18,154,164
Beginning balance at Mar. 31, 2021	350,783	$ 19	291,603	110,287	(20,334)	(30,792)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(1,176)			(1,176)
Currency translation adjustment	4,867				4,867
Stock-based compensation	3,283		3,283
Common stock issued, net of shares withheld for employee taxes (in shares)		20,709
Common stock issued, net of shares withheld for employee taxes	(395)	$ 1	(396)
Ending balance (in shares) at Jun. 30, 2021		18,174,873
Ending balance at Jun. 30, 2021	357,362	$ 20	294,490	109,111	(15,467)	(30,792)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(3,855)			(3,855)
Currency translation adjustment	(328)				(328)
Stock-based compensation	3,280		3,280
Common stock issued, net of shares withheld for employee taxes (in shares)		27,543
Common stock issued, net of shares withheld for employee taxes	$ 312		312
Ending balance (in shares) at Sep. 30, 2021	19,384,350	18,202,416
Ending balance at Sep. 30, 2021	$ 356,771	$ 20	$ 298,082	$ 105,256	$ (15,795)	$ (30,792)