Consolidated Statements Of Stockholders' Deficit - USD ($) $ in Thousands	Total	Series A Preferred Stock	Preferred Shares	Preferred Shares Series A Preferred Stock	Common Shares	Treasury Stock	Additional Paid-in Capital	Additional Paid-in Capital Series A Preferred Stock	Accumulated Deficit
Balance at Dec. 31, 2014	$ (88,448)				$ 143,113	$ (217)	$ 738,890		$ (970,234)
Balance (in shares) at Dec. 31, 2014					174,610,451	(20,079)
Issuance of stock		$ 57,853		$ 29,168				$ 28,685
Issuance of stock (shares)				391,017,970
Conversion of Series A Convertible Preferred Stock, net	(187)		$ (4,804)		$ 4,804		(187)
Conversion of Series A Convertible Preferred Stock, net (in shares)			(62,833,330)		6,283,333
Preferred stock purchase option	946						1,814		(868)
Preferred stock beneficial conversion features							32,987		(32,987)
Exercise of warrants	$ 2,713				$ 1,429		1,284
Exercise of warrants (in shares)	1,844,585				1,844,585
Exercise of stock options	$ 31				$ 13		18
Exercise of stock options (in shares)					18,020
Vesting of restricted stock units	(194)				$ 619	$ (194)	(619)
Vesting of restricted stock units (in shares)					821,376	(154,423)
Reacquisition of conversion option in convertible notes	(1,300)						(1,300)
Tax benefits realized from stock-based compensation	727						727
Stock-based compensation	13,872						13,872
Net loss	(115,204)								(115,204)
Balance (Scenario, Previously Reported) at Dec. 31, 2015	(129,191)		$ 24,364		$ 149,978	$ (411)	816,171		(1,119,293)
Balance (Cumulative-effect adjustment)	1,639								1,639
Balance at Dec. 31, 2015	(127,552)		$ 24,364		$ 149,978	$ (411)	816,171		(1,117,654)
Balance (in shares) (Scenario, Previously Reported) at Dec. 31, 2015			328,184,640		183,577,765	(174,502)
Balance (in shares) at Dec. 31, 2015			328,184,640		183,577,765	(174,502)
Issuance of stock	64,613				$ 15,712		48,901
Issuance of stock (shares)					24,265,000
Exchange of exchangeable senior notes, net of transaction costs	127,436				$ 40,062		87,374
Conversion of Series A Convertible Preferred Stock, net (in shares)					60,311,188
Exercise of stock options	$ 287				$ 119		168
Exercise of stock options (in shares)	177,146				177,146
Vesting of restricted stock units	$ (1,094)				$ 1,295	$ (1,087)	(1,302)
Vesting of restricted stock units (in shares)					1,852,102	(645,003)
Stock-based compensation	13,602						13,602
Net loss	(86,350)								(86,350)
Balance at Dec. 31, 2016	(9,058)		$ 24,364		$ 207,166	$ (1,498)	964,914		(1,204,004)
Balance (in shares) at Dec. 31, 2016			328,184,640		270,183,201	(819,505)
Exercise of stock options	$ 638				$ 229		409
Exercise of stock options (in shares)	356,656				356,656
Vesting of restricted stock units	$ (2,767)				$ 1,373	$ (2,731)	(1,409)
Vesting of restricted stock units (in shares)					2,179,187	(877,528)
Stock-based compensation	13,952						13,952
Net loss	(67,865)								(67,865)
Balance at Dec. 31, 2017	$ (65,100)		$ 24,364		$ 208,768	$ (4,229)	$ 977,866		$ (1,271,869)
Balance (in shares) at Dec. 31, 2017			328,184,640		272,719,044	(1,697,033)