Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Trade receivables, allowances	$ 6.1	$ 7.8
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	12,000,000	12,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	600,000,000	600,000,000
Common stock, shares issued (in shares)	286,300,000	286,300,000
Common stock, shares outstanding (in shares)	237,100,000	237,800,000
Common stock held in employee benefit trust (in shares)	200,000	200,000
Common stock held in treasury (in shares)	49,000,000	48,300,000