Condensed Consolidated Balance Sheets [Parenthetical] - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	51,697,864	44,974,248
Common stock, shares outstanding	51,656,555	44,932,939