Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) (USD $) In Thousands	Total	Class A Common Stock	Class B Common Stock	Convertible Preferred Stock	Additional Paid-in Capital	Deficit accumulated during development stage	Series A Convertible Preferred Stock	Series A Convertible Preferred Stock Class B Common Stock	Series A Convertible Preferred Stock Additional Paid-in Capital	Series A-1 Convertible Preferred Stock	Series A-1 Convertible Preferred Stock Class B Common Stock	Series A-1 Convertible Preferred Stock Additional Paid-in Capital	Series B Convertible Preferred Stock	Series B Convertible Preferred Stock Class A Common Stock	Series B Convertible Preferred Stock Additional Paid-in Capital	Series C Convertible Preferred Stock	Series C Convertible Preferred Stock Class A Common Stock	Series C Convertible Preferred Stock Additional Paid-in Capital
Beginning Balance at Dec. 31, 2010	$ (62,123)		$ 2	$ 134,384	$ 4,199	$ (66,324)
Beginning Balance, shares at Dec. 31, 2010		60	15,820	69,052
Stock issued during period, shares, new issues		10,800		11,220
Stock issued during period, value, new issues	148,647	1		55,000	148,646
Common Stock Issued - Restricted, shares		44
Stock Based Compensation - Options	3,212				3,212
Stock Based Compensation - Restricted	1,575				1,575
Stock Options/Warrants Exercised, shares		227	1,457
Stock Options/Warrants Exercised	126				126
Conversion of Preferred Stock, shares							(24,000)	24,000		(20,572)	20,572		(24,480)	24,480		(11,220)	4,583
Conversion of Preferred Stock	134,384						4,360	2	4,358	10,024	2	10,022	120,000	2	119,998	55,000	1	54,999
Conversion of Convertible Preferred Stock Warrants Liability	10,399				10,399
Beneficial Conversion Feature on Issuance of Series C Convertible Preferred Stock and Stock Warrants	19,669				19,669
Deemed dividend related to the beneficial conversion feature of Series C convertible preferred stock	(19,669)				(19,669)
Net loss	(49,114)					(49,114)
Ending Balance at Sep. 30, 2011	$ 242,106	$ 4	$ 6		$ 357,534	$ (115,438)
Ending Balance, shares at Sep. 30, 2011		40,194	61,849