Condensed Consolidated Balance Sheets (Parenthetical) (USD $)
Jun. 30, 2014
Dec. 31, 2013
Statement of Financial Position [Abstract]    
Common stock, par value per share (in USD per share) $ 0.01 $ 0.01
Common stock, shares issued 399,030,681 370,570,565
Common stock, shares outstanding 398,812,745 370,363,803