Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Accounts receivable, allowances	$ 84.6	$ 79.7
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5	5
Preferred stock, shares issued
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	300	300
Common stock, shares issued	155.6	139.0
Treasury stock, shares	26.9	21.7