CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 22.9	$ 20.5
Preferred stock, par value (in dollars per share)	$ 0.00	$ 0.00
Preferred stock, Authorized shares	5,000,000	5,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.00	$ 0.00
Common stock, Authorized shares	200,000,000	200,000,000
Common stock, Issued shares	76,920,713	76,042,546
Common stock, outstanding shares	76,920,713	76,042,546