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, 2018	$ 1,096,162	$ 376	$ 34,953	$ 1,205,946	$ (145,113)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment	1,627				1,627
Net loss	(6,051)			(6,051)
Comprehensive loss	(4,424)
Repurchase of common stock	(1,116)			(1,116)
Stock option expense	4,862		4,862
Other	(79)			(79)
Ending Balance at Mar. 31, 2019	1,095,405	376	39,815	1,198,700	(143,486)
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)
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)