Common Stock (Tables)

9 Months Ended

Sep. 30, 2012

Common Stock

Schedule of shares reserved for future issuance

(in thousands)	December 31, 2011	September 30, 2012
Conversion of Series B, Series C, Series D, Series E, Series F and Series G convertible preferred stock	66,256	—
Convertible preferred stock warrants	302	—
Common stock warrants	2,640	2,891
Options to purchase common stock	17,617	19,812
	86,815	22,703