Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Receivables, net of allowance for doubtful accounts	$ 25.9	$ 16.2
Preferred stock, par value per share	$ 0.10	$ 0.10
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Common stock, par value per share	$ 0.10	$ 0.10
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	204,660,621	202,528,616
Common stock, shares outstanding	194,557,669	192,062,185
Common stock reserved for issuance related to Settlement agreement, par value per share	$ 0.10	$ 0.10
Common stock reserved for issuance related to Settlement agreement, shares	18,000,000	18,000,000
Common stock in treasury, shares	10,102,952	10,466,431