Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 13.9	$ 18.9
Property, plant and equipment, accumulated depreciation	850.9	642.1
Intangible assets, accumulated amortization	$ 29.9	$ 21.6
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	37,500,000	37,500,000
Common stock, shares issued	26,478,175	26,288,998
Common stock, shares outstanding	26,478,175	26,288,998