Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2011	Dec. 31, 2010
Stockholders' equity (deficit):
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	10,949,812	1,205,624
Common stock, shares outstanding	10,949,812	1,205,624
Series B preferred stock
Temporary equity:
Preferred stock, par value		$ 0.00001
Preferred stock, shares authorized		17,065,217
Preferred stock, shares issued		9,782,609
Preferred stock, shares outstanding		9,782,609
Series C preferred stock
Temporary equity:
Preferred stock, par value		$ 0.00001
Preferred stock, shares authorized		16,798,924
Preferred stock, shares issued		11,072,239
Preferred stock, shares outstanding		11,072,239
Series D preferred stock
Temporary equity:
Preferred stock, par value		$ 0.00001
Preferred stock, shares authorized		67,000,000
Preferred stock, shares issued		30,156,259
Preferred stock, shares outstanding		30,156,259
Series A preferred stock
Temporary equity:
Preferred stock, par value		$ 0.00001
Preferred stock, shares authorized		2,544,750
Preferred stock, shares issued		2,544,750
Preferred stock, shares outstanding		2,544,750