Derivative Instruments Fair Value of Derivative Instruments (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	$ 9.1	$ 0
Derivative liability, fair value	0.7	0.9
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	9.1	0
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0.7	0.9
Foreign Currency Forward Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	9.1	0
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Accounts Payable and Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0.7	0
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities and Deferred Credits [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	$ 0	$ 0.9