Fair Value Measurements and Risk (Details 2) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Fair values of derivative instruments
Asset Derivatives	$ 12.4	$ 20.4
Liability Derivatives	5.0	4.3
Derivatives designated as hedging instruments under ASC 815 | Other current assets
Fair values of derivative instruments
Asset Derivatives, Currency contracts	0.3
Derivatives designated as hedging instruments under ASC 815 | Other current liabilities
Fair values of derivative instruments
Liability Derivatives, Commodity contracts	4.5	3.8
Liability Derivatives, Currency contracts	0.1	0.4
Derivatives designated as hedging instruments under ASC 815 | Other liabilities
Fair values of derivative instruments
Liability Derivatives, Commodity contracts		0
Derivatives not designated as hedging instruments under ASC 815 | Other current assets
Fair values of derivative instruments
Asset Derivatives, Currency contracts	6.3	13.1
Derivatives not designated as hedging instruments under ASC 815 | Other current liabilities
Fair values of derivative instruments
Liability Derivatives, Currency contracts	0.4	0.1
Derivatives not designated as hedging instruments under ASC 815 | Other assets
Fair values of derivative instruments
Asset Derivatives, Currency contracts	$ 5.8	$ 7.3