Preferred Stock Warrants and Warrant Liability (Details)	Dec. 31, 2010
Information relating Preferred Stock Warrants
Remaining Number Outstanding	41,558,259
Series C Warrants-2008 Loan and Security Agreement [Member]
Information relating Preferred Stock Warrants
Remaining Number Outstanding	280,803
Exercise price	0.7345
Series D Warrants-2009 Convertible Debt [Member]
Information relating Preferred Stock Warrants
Remaining Number Outstanding	4,368,948
Exercise price	0.1198
Series D Warrants-Series D Preferred Stock Issuance [Member]
Information relating Preferred Stock Warrants
Remaining Number Outstanding	8,347,236
Exercise price	0.1198
Series D Warrants-1st Amendment [Member]
Information relating Preferred Stock Warrants
Remaining Number Outstanding	6,243,362
Exercise price	0.1198
Series D Warrants-2nd Amendment [Member]
Information relating Preferred Stock Warrants
Remaining Number Outstanding	8,694,558
Exercise price	0.1198
Series D Warrants-3rd Amendment [Member]
Information relating Preferred Stock Warrants
Remaining Number Outstanding	4,462,227
Exercise price	0.1198
Series D Warrants-5th Amendment [Member]
Information relating Preferred Stock Warrants
Remaining Number Outstanding	2,260,440
Exercise price	0.1198
Series D Warrants-6th Amendment [Member]
Information relating Preferred Stock Warrants
Remaining Number Outstanding	6,900,685
Exercise price	0.1198