CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Losses
Beginning Balance at Dec. 31, 2016	$ 1,356,424	$ 375	$ 5,468	$ 1,500,988	$ (150,407)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment	24,117				24,117
Net income (loss)	(100,639)			(100,639)
Total comprehensive income (loss)	(76,522)
Options exercised and awards vested	560		560
Stock option expense	14,270		14,270
Other	(271)	(3)	(215)	(53)
Ending Balance at Dec. 31, 2017	1,294,461	372	20,083	1,400,296	(126,290)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment	(18,823)				(18,823)
Net income (loss)	(95,695)			(95,695)
Total comprehensive income (loss)	(114,518)
Repurchase of common stock	(100,000)	(20)		(99,980)
Options exercised and awards vested	1,616	25	1,591
Stock option expense	13,459		13,459
ASC 606 Implementation	1,683			1,683
Other	(539)	(1)	(180)	(358)
Ending 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	1,550				1,550
Net income (loss)	1,720			1,720
Total comprehensive income (loss)	3,270
Repurchase of common stock	(26,570)	(6)		(26,564)
Options exercised and awards vested	2,181		2,181
Stock option expense	15,721		15,721
Other	(63)	1	15	(79)
Ending Balance at Dec. 31, 2019	$ 1,090,701	$ 371	$ 52,870	$ 1,181,023	$ (143,563)