CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Stockholders’ equity:
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, Authorized shares	5,000,000	5,000,000
Convertible preferred stock, Issued shares	0	0
Convertible preferred stock, Outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, Authorized shares	500,000,000	500,000,000
Common stock, Issued shares	112,460,439	111,525,021
Common stock, Outstanding shares	112,460,439	111,525,021