Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 10.3	$ 9.9
Property, plant and equipment, accumulated depreciation	1,178.5	1,085.4
Intangible assets, accumulated amortization	$ 49.2	$ 43.7
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	37,500,000	37,500,000
Common stock, shares issued	26,902,696	26,710,569
Common stock, shares outstanding	26,902,696	26,710,569