Common Stock - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Stockholders Equity Note [Abstract]
Common stock, authorized	200,000,000	200,000,000
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, issued	78,350,361	65,881,122
Common stock, outstanding	78,350,361	65,881,122
Shares issued upon the exercise of stock options	493,497
Cash proceeds	$ 362,960
Shares issued upon the exercise of warrants	11,942,870
Warrants to purchase through cashless exercise provisions	235,726
Shares issued through cashless exercise provisions	129,536
Warrants to purchase exercised through cash	11,813,394
Proceeds from warrants exercise	15,952,000
Common stock issued	32,872
Fair Value of common stock issued	$ 98,633