Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Common Stock
Common Stock, Par Value	$ 0.01	$ 0.01
Common Stock, Shares Authorized	640,000,000	640,000,000
Common Stock, Shares Issued	271,958,495	269,323,084
Treasury Stock
Common Stock Held in Treasury, Shares	326,264	303,633