CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 20.5	$ 22.2
Preferred stock, Authorized shares	5,000,000	5,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, Authorized shares	200,000,000	100,000,000
Common stock, Issued shares	76,042,546	75,007,694
Common stock, outstanding shares	76,042,546	75,007,694