Fair Value Measurements and Risk (Details 2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair values of derivative instruments
Asset Derivatives	$ 25.8	$ 20.4
Liability Derivatives	0.6	4.3
Derivatives designated as hedging instruments under ASC 815 | Other current assets
Fair values of derivative instruments
Asset Derivatives, Commodity contracts	0.6
Asset Derivatives, Currency contracts	0.8
Derivatives designated as hedging instruments under ASC 815 | Other current liabilities
Fair values of derivative instruments
Liability Derivatives, Commodity contracts	0.4	3.8
Liability Derivatives, Currency contracts		0.4
Derivatives not designated as hedging instruments under ASC 815 | Other current assets
Fair values of derivative instruments
Asset Derivatives, Currency contracts	16.1	13.1
Derivatives not designated as hedging instruments under ASC 815 | Other current liabilities
Fair values of derivative instruments
Liability Derivatives, Currency contracts	0.2	0.1
Derivatives not designated as hedging instruments under ASC 815 | Other assets
Fair values of derivative instruments
Asset Derivatives, Currency contracts	$ 8.3	$ 7.3