Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares
Sep. 30, 2016
Dec. 31, 2015
Statement of Financial Position [Abstract]    
Common stock par value (in dollars per share) $ 0.001 $ 0.001
Common stock shares authorized (in shares) 300,000,000 300,000,000
Common stock shares issued (in shares) 100,850,257 95,877,947
Common stock shares outstanding (in shares) 93,647,679 95,832,238
Preferred stock par value (in dollars per share) $ 0.001 $ 0.001
Preferred stock shares authorized (in shares) 10,000,000 10,000,000
Preferred stock, shares issued (in shares) 0 0
Preferred stock, shares outstanding (in shares) 0 0
Treasury stock, shares held (in shares) 7,202,578 0