Consolidated Statements of Convertible Preferred Stock, Non-controlling Interest and Stockholders' (Deficit) Equity (USD $)	Total	Common stock	Additional paid-in capital	Accumulated Other Comprehensive Loss	Accumulated deficit
Balance at Dec. 31, 2009	$ (190,762,000)	$ 17,364,000	$ 13,386,000		$ (221,512,000)
Balance (in shares) at Dec. 31, 2009		10,868,000
Increase (decrease) in stockholders' equity
Exercise of stock options	294,000	294,000
Exercise of stock options (in shares)		205,000
Stock-based compensation	4,551,000		4,551,000
Series F amount interest	12,974,000		12,974,000
Change in par value		(17,547,000)	17,547,000
Ownership change in non-controlling interest	3,083,000		3,083,000
Loss attributable to non-controlling interest	55,000				55,000
Net loss	(50,159,000)				(50,159,000)
Balance at Dec. 31, 2010	(219,964,000)	111,000	51,541,000		(271,616,000)
Balance ( in shares ) at Dec. 31, 2010		11,073,000
Increase (decrease) in stockholders' equity
Exercise of stock options	1,029,000	4,000	1,025,000
Exercise of stock options (in shares)		467,000
Exercise of common stock warrants	716,000	3,000	713,000
Exercise of common stock warrants (in shares)		294,000
Stock-based compensation	6,952,000		6,952,000
Loss attributable to non-controlling interest	453,000				453,000
Net loss	(79,676,000)				(79,676,000)
Balance at Dec. 31, 2011	(290,490,000)	118,000	60,231,000		(350,839,000)
Balance ( in shares ) at Dec. 31, 2011		11,834,000
Increase (decrease) in stockholders' equity
Exercise of stock options	5,400,000	26,000	5,374,000
Exercise of stock options (in shares)	2,622,000	2,622,000
Exercise of common stock warrants	27,000	1,000	26,000
Exercise of common stock warrants (in shares)		71,000
Stock-based compensation	6,889,000		6,889,000
Conversion of convertible preferred stock into common stock	268,225,000	663,000	267,562,000
Conversion of convertible preferred stock into common stock (in shares)		66,256,000
Initial public offering, net of offering costs	98,081,000	150,000	97,931,000
Initial public offering, net of offering costs (in shares)		15,042,000
Series B dividends declared	(4,263,000)		(4,263,000)
Conversion of convertible preferred stock warrants to common stock warrants	929,000		929,000
Other comprehensive loss	(38,000)			(38,000)
Loss attributable to non-controlling interest	477,000				477,000
Net loss	(91,754,000)				(91,754,000)
Balance at Dec. 31, 2012	$ (6,517,000)	$ 958,000	$ 434,679,000	$ (38,000)	$ (442,116,000)
Balance ( in shares ) at Dec. 31, 2012		95,825,000