Fair Value Measurements and Risk (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair values of derivative instruments
Asset Derivatives	$ 1.4	$ 20.4
Liability Derivatives	5.5	4.3
Derivatives designated as hedging instruments under ASC 815 | Other current assets
Fair values of derivative instruments
Asset Derivatives, Commodity contracts	0.2	0
Asset Derivatives, Currency contracts	1.2	0
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	0.2	0.4
Derivatives not designated as hedging instruments under ASC 815 | Other current assets
Fair values of derivative instruments
Asset Derivatives, Currency contracts	0	13.1
Derivatives not designated as hedging instruments under ASC 815 | Other assets
Fair values of derivative instruments
Asset Derivatives, Currency contracts	0	7.3
Derivatives not designated as hedging instruments under ASC 815 | Other current liabilities
Fair values of derivative instruments
Liability Derivatives, Currency contracts	4.9	0.1
Derivatives not designated as hedging instruments under ASC 815 | Other liabilities
Fair values of derivative instruments
Liability Derivatives, Currency contracts	$ 0	$ 0