Condensed Consolidated Balance Sheets (Parenthetical) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Statement Of Financial Position [Abstract]    
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 2,000,000 2,000,000
Preferred stock, shares issued 0 0
Preferred stock, shares outstanding 0 0
Common stock, par value $ 0.001 $ 0.001
Common stock, shares authorized 150,000,000 150,000,000
Common stock, shares issued 71,334,362 62,898,233
Common stock, shares outstanding 71,334,362 62,898,233