Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Cumulative effect of accounting change	Common Stock	Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Retained Earnings Cumulative effect of accounting change	Treasury Stock
Beginning balance at Dec. 31, 2019	$ 548,645	$ (735)	$ 1,067	$ 620,626	$ (67,947)	$ 134,119	$ (735)	$ (139,220)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(12,148)					(12,148)
Employee stock options, restricted stock and employee stock purchase plan	498			(103)		(735)		1,336
Stock-based compensation expense	1,592			1,592
Foreign currency translation, net of tax	(7,493)				(7,493)
Ending balance at Mar. 31, 2020	530,359		1,067	622,115	(75,440)	120,501		(137,884)
Beginning balance at Dec. 31, 2020	488,032		1,076	627,031	(54,172)	50,937		(136,840)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(5,362)					(5,362)
Employee stock options, restricted stock and employee stock purchase plan	257		1	242		(21)		35
Stock-based compensation expense	1,279			1,279
Foreign currency translation, net of tax	(3,284)				(3,284)
Ending balance at Mar. 31, 2021	$ 480,922		$ 1,077	$ 628,552	$ (57,456)	$ 45,554		$ (136,805)