Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 3.2	$ 3.6
Property, plant and equipment, accumulated depreciation	1,503.2	1,452.9
Intangible assets, accumulated amortization	$ 68.1	$ 65.3
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	27,266,792	27,074,398
Common stock, shares outstanding	27,266,792	27,074,398