CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Losses
Beginning Balance at Dec. 31, 2019	$ 1,090,701	$ 371	$ 52,870	$ 1,181,023	$ (143,563)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment	(24,979)				(24,979)
Net loss	(19,698)			(19,698)
Total comprehensive loss	(44,677)
Repurchase of common stock	(25,008)	(8)		(25,000)
Stock option expense	3,176		3,176
Other	9		(1)	10
Ending Balance at Mar. 31, 2020	1,024,201	363	56,045	1,136,335	(168,542)
Beginning Balance at Dec. 31, 2020	1,041,528	363	65,613	1,125,263	(149,711)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment	(2,090)				(2,090)
Net loss	(34,358)			(34,358)
Total comprehensive loss	(36,448)
Stock option expense	3,186		3,186
Ending Balance at Mar. 31, 2021	$ 1,008,266	$ 363	$ 68,799	$ 1,090,905	$ (151,801)