v2.4.0.6
Consolidated Balance Sheets (Parenthetical) (USD $)
Jun. 30, 2012
Dec. 31, 2011
Consolidated Balance Sheets [Abstract]    
Common stock, par value (in dollars per share) $ 0.10 $ 0.10
Common stock, shares authorized (in shares) 1,000,000,000 1,000,000,000
Common stock, shares issued (in shares) 404,500,000 404,100,000