Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Common Stock
Common Stock, Par Value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, Shares Authorized (in shares)	640,000,000	640,000,000
Common Stock, Shares Issued (in shares)	550,150,823	549,028,374
Treasury Stock
Common Stock Held in Treasury (in shares)	292,179	733,517