CONSOLIDATED STATEMENTS OF STOCKHOLDERS' (DEFICIT) EQUITY (USD $) In Thousands, except Share data	Total	Common Shares	Additional Paid-in Capital	Treasury Stock	Accumulated Deficit
Beginning Balance at Dec. 31, 2009	$ 6,597	$ 84,219	$ 172,339	$ (217)	$ (249,744)
Beginning Balance (in shares) at Dec. 31, 2009		98,801,982
Exercise of warrants (in shares)		6,344,136
Exercise of warrants	8,904	4,906	3,998
Exercise of stock options (in shares)		1,706,016
Exercise of stock options	3,642	1,336	2,306
Tax benefits realized from stock-based compensation	543		543
Transfer of fair value of warrants exercised from liabilities to equity	22,317		22,317
Share issuances for services (in shares)		4,597
Share issuances for services	12	4	8
Stock-based compensation	5,207		5,207
Net loss	(249,589)				(249,589)
Ending Balance at Dec. 31, 2010	(202,367)	90,465	206,718	(217)	(499,333)
Ending Balance (in shares) at Dec. 31, 2010		106,856,731
Exercise of warrants (in shares)	12,888,369	12,888,369
Exercise of warrants	18,702	10,289	8,413
Exercise of stock options (in shares)	2,273,221	2,273,221
Exercise of stock options	5,094	1,833	3,261
Stock issued in January financing (in shares)		13,800,000
Stock issued in January financing	98,654	10,723	87,931
Tax benefits realized from stock-based compensation	4,199		4,199
Transfer of fair value of warrants exercised from liabilities to equity	129,517		129,517
Share issuances for services (in shares)		14,221
Share issuances for services	71	11	60
Stock-based compensation	9,294		9,294
Net loss	(69,126)				(69,126)
Ending Balance at Dec. 31, 2011	(5,962)	113,321	449,393	(217)	(568,459)
Ending Balance (in shares) at Dec. 31, 2011		135,832,542
Exercise of warrants (in shares)	11,047,579	11,047,579
Exercise of warrants	16,720	8,540	8,180
Exercise of stock options (in shares)	3,380,413	3,380,413
Exercise of stock options	8,205	2,659	5,546
Vesting of restricted stock units (in shares)		97,398
Vesting of restricted stock units		76	(76)
Conversion option contained in exchangeable notes	22,898		22,898
Tax benefits realized from stock-based compensation	11,334		11,334
Transfer of fair value of warrants exercised from liabilities to equity	103,885		103,885
Share issuances for services (in shares)		3,001
Share issuances for services	32	1	31
Stock-based compensation	18,075		18,075
Net loss	(179,184)				(179,184)
Ending Balance at Dec. 31, 2012	$ (3,997)	$ 124,597	$ 619,266	$ (217)	$ (747,643)
Ending Balance (in shares) at Dec. 31, 2012		150,360,933