CONSOLIDATED BALANCE SHEET (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Statement of Financial Position [Abstract]
Common stock, par value per share	$ 0.10	$ 0.10
Common stock, shares authorized	500.0	500.0
Common stock, shares issued	127.2	126.9
Common stock held in treasury, shares	24.0	24.0