Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Common Stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	240,000,000	240,000,000
Common stock, shares issued	72,670,673	70,861,822
Common stock, shares outstanding	72,566,426	70,801,782
Non-Voting Common Stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	0	1,669,205
Common stock, shares outstanding	0	1,669,205