Property, Plant and Equipment, net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Property, plant and equipment, net
Gross property, plant and equipment	$ 371.0		$ 361.3
Less: Accumulated depreciation and amortization	229.7		233.2
Net property, plant and equipment	141.3		128.1
Net capitalized turnaround costs:
Beginning balance	2.6	6.5
Depreciation	(1.0)	(0.8)
Ending balance	1.6	5.7
Land
Property, plant and equipment, net
Gross property, plant and equipment	1.6		1.6
Building and improvements
Property, plant and equipment, net
Gross property, plant and equipment	7.6		7.6
Plant and equipment
Property, plant and equipment, net
Gross property, plant and equipment	301.2		306.4
Construction in progress
Property, plant and equipment, net
Gross property, plant and equipment	$ 60.6		$ 45.7