Consolidated Statements of Changes in Shareholders' Deficit - USD ($) $ in Thousands	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Deficit	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Dec. 31, 2014		$ 813	$ (28,414)	$ 956,146	$ (1,635,277)	$ (1,282)	$ (708,014)
Balance (in shares) at Dec. 31, 2014	8,624	79,161,817
Increase (Decrease) in Shareholders' Deficit
Share-based compensation arrangements, net of tax benefits of $6,896 and $14,826 for the years ended December 31, 2016 and 2015 respectively		$ 17		32,540			32,557
Share-based compensation arrangements (in shares)		1,727,458
Foreign currency translation adjustment						(3,272)	(3,272)
Net income (loss)					686		686
Balance at Dec. 31, 2015		$ 830	(28,414)	988,686	(1,634,591)	(4,554)	(678,043)
Balance (in shares) at Dec. 31, 2015	8,624	80,889,275
Increase (Decrease) in Shareholders' Deficit
Share-based compensation arrangements, net of tax benefits of $6,896 and $14,826 for the years ended December 31, 2016 and 2015 respectively		$ 16		25,519			25,535
Share-based compensation arrangements (in shares)		1,609,033
Foreign currency translation adjustment						(122)	(122)
Conversion of preferred stock		$ 86		(86)
Conversion of preferred stock (in shares)	(8,624)	8,624,000
Net income (loss)					109,310		109,310
Balance at Dec. 31, 2016		$ 932	(28,414)	1,014,119	(1,525,281)	(4,676)	(543,320)
Balance (in shares) at Dec. 31, 2016		91,122,308
Increase (Decrease) in Shareholders' Deficit
Share-based compensation arrangements, net of tax benefits of $6,896 and $14,826 for the years ended December 31, 2016 and 2015 respectively		$ 14		18,270			18,284
Share-based compensation arrangements (in shares)		1,367,083
Foreign currency translation adjustment						3,223	3,223
Share repurchases		$ (13)		(24,783)			(24,796)
Share repurchases (in shares)		(1,264,149)
Net income (loss)					473,463		473,463
Balance at Dec. 31, 2017		$ 933	$ (28,414)	$ 1,007,606	$ (1,051,818)	$ (1,453)	$ (73,146)
Balance (in shares) at Dec. 31, 2017		91,225,242