Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2013
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 0.1	$ 1.2
Property, plant and equipment, accumulated depreciation and amortization	$ 1,143.6	$ 1,079.2
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock shares authorized (in shares)	20,000,000	20,000,000
Preferred stock shares outstanding (in shares)	0	0
Common stock par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock shares authorized (in shares)	200,000,000	200,000,000
Common stock shares issued (in shares)	46,767,164	46,767,164
Treasury stock, shares held (in shares)	17,589,533	16,307,048