Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 4.6	$ 8.3
Property, plant and equipment, accumulated depreciation	1,377.6	1,281.2
Intangible assets, accumulated amortization	$ 59.8	$ 54.3
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	37,500,000	37,500,000
Common stock, shares issued	27,050,600	26,921,066
Common stock, shares outstanding	27,050,600	26,921,066