Fair Value Measurements (Details 2) (Assets and liabilities measured on a nonrecurring basis, USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Level 3
Major categories of assets and liabilities measured on a recurring basis, at fair value
Property, plant and equipment, net	$ 92.0	$ 86.1
Goodwill	55.8	55.8
Intangible assets, net	24.7	25.9
Total	172.5	167.8
Fair Value
Major categories of assets and liabilities measured on a recurring basis, at fair value
Property, plant and equipment, net	92.0	86.1
Goodwill	55.8	55.8
Intangible assets, net	24.7	25.9
Total	$ 172.5	$ 167.8