Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Preferred stock, no par value
Preferred stock, shares authorized	25.0	25.0
Preferred stock, issued
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	900.0	900.0
Common stock, shares issued	395.7	395.7
Treasury stock, shares	146.6	139.0