Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Common Stock- Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interest
Beginning Balance at Dec. 31, 2016	$ 610,174	$ 5	$ 480,906	$ 214,007	$ (5,751)	$ (81,824)	$ 2,831
Beginning Balance (in shares) at Dec. 31, 2016		38,553,413
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of restricted stock units to common stock (net of shares of treasury stock purchased)	(872)					(872)
Conversion of restricted stock units to common stock (net of shares of treasury stock purchased) (in shares)		210,611
Settlement of stock appreciation rights in common stock (net of shares of treasury stock purchased)	(385)					(385)
Settlement of stock appreciation rights in common stock (net of shares of treasury stock purchased) (in shares)		73,725
Acquisition of noncontrolling interest	(3,102)		(271)				(2,831)
Impact of 2036 Senior Notes conversion liability reclassification, net of tax	27,908		27,908
Stock compensation expense	6,909		6,909
Foreign currency translation adjustment	6,029				6,029
Net change in unrealized losses on marketable securities	0
Net income (loss)	(79,079)			(79,079)
Ending Balance at Dec. 31, 2017	567,582	$ 5	515,452	134,928	278	(83,081)	0
Ending Balance (in shares) at Dec. 31, 2017		38,837,749
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of restricted stock units to common stock (net of shares of treasury stock purchased)	(2,280)					(2,280)
Conversion of restricted stock units to common stock (net of shares of treasury stock purchased) (in shares)		293,717
Settlement of stock appreciation rights in common stock (net of shares of treasury stock purchased)	(1,191)					(1,191)
Settlement of stock appreciation rights in common stock (net of shares of treasury stock purchased) (in shares)		140,332
Convertible debt extinguishment impact, net of tax	(70,689)		(70,689)
Treasury stock repurchases	(25,048)					(25,048)
Treasury stock activity (in shares)		(1,937,844)
Unwind of capped call options	85		252			(167)
Partial termination of capped call options (in shares)		(15,012)
Stock compensation expense	6,412		6,412
Foreign currency translation adjustment	(1,906)				(1,906)
Net change in unrealized losses on marketable securities	(28)				(28)
Net income (loss)	292,316			292,316
Ending Balance at Dec. 31, 2018	765,253	$ 5	451,427	427,244	(1,656)	(111,767)	0
Ending Balance (in shares) at Dec. 31, 2018		37,318,942
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of restricted stock units to common stock (net of shares of treasury stock purchased)	(3,317)					(3,317)
Conversion of restricted stock units to common stock (net of shares of treasury stock purchased) (in shares)		345,655
Settlement of stock appreciation rights in common stock (net of shares of treasury stock purchased)	(232)		(31)			(201)
Settlement of stock appreciation rights in common stock (net of shares of treasury stock purchased) (in shares)		26,346
Convertible debt extinguishment impact, net of tax	(9,715)		(9,715)
Settlement of 2019 Convertible Debt in common stock, net of 1,902,781 shares of treasury stock	0		(18,779)			18,779
Settlement of 2019 Convertible Debt in common stock, net of 1,902,781 shares of treasury stock (in shares)		1,902,781
Unwind of capped call options	0		8,982			(8,982)
Partial termination of capped call options (in shares)		(626,645)
Stock compensation expense	6,707		6,707
Foreign currency translation adjustment	(338)				(338)
Net change in unrealized losses on marketable securities	0
Net income (loss)	380,064			380,064
Ending Balance at Dec. 31, 2019	$ 1,131,906	$ 5	$ 438,591	$ 800,792	$ (1,994)	$ (105,488)	$ 0
Ending Balance (in shares) at Dec. 31, 2019		38,967,079