Property, Plant and Equipment, net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Property, plant and equipment, net
Document Period End Date			Jun. 30, 2016
Gross property, plant and equipment	$ 587.1		$ 587.1		$ 572.5
Less: Accumulated depreciation and amortization	280.3		280.3		265.5
Net property, plant and equipment	306.8		306.8		307.0
Loss on disposal of property, plant and equipment	0.1	$ 0.2	0.1	$ 1.2
Net capitalized turnaround costs:
Beginning balance			37.8	16.7
Additions			2.1	30.7
Depreciation			(7.5)	(5.0)
Ending balance	32.4	$ 42.4	32.4	$ 42.4
Land
Property, plant and equipment, net
Gross property, plant and equipment	1.6		1.6		1.6
Buildings and improvements
Property, plant and equipment, net
Gross property, plant and equipment	16.5		16.5		14.5
Machinery and equipment
Property, plant and equipment, net
Gross property, plant and equipment	555.6		555.6		537.5
Construction in progress
Property, plant and equipment, net
Gross property, plant and equipment	$ 13.4		$ 13.4		$ 18.9