Derivative Instruments And Hedging Activities (Schedule Of Derivative Instruments In Statement Of Financial Position, Fair Value) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	78.8	165.9
Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	3.6	23.0
Accounts Receivable [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value		83.8
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	9.6	5.2
Designated as Hedging Instrument [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	2.5	3.5
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Description of Location of Foreign Currency Derivatives on Balance Sheet	Othercurrentliabilities	Othercurrentliabilities
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Derivative Assets (Current) [Member]
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Derivative Instrument Assets at Fair Value	9.6	5.2
Description of Location of Foreign Currency Derivatives on Balance Sheet	Derivativeassets(current)	Derivativeassets(current)
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value	2.5	3.5
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	69.2	160.7
Not Designated as Hedging Instrument [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	1.1	19.5
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Derivative Assets (Current) [Member]
Derivatives, Fair Value [Line Items]
Description of Location of Foreign Currency Derivatives on Balance Sheet	Derivativeassets(current)	Derivativeassets(current)
Derivative asset, fair value		2.8
Not Designated as Hedging Instrument [Member] | Customer Contracts [Member] | Derivative Assets (Current) [Member]
Derivatives, Fair Value [Line Items]
Description of Location of Foreign Currency Derivatives on Balance Sheet	Derivativeassets(current)	Derivativeassets(current)
Derivative asset, fair value	65.1	72.9
Not Designated as Hedging Instrument [Member] | Provisional Pricing Arrangements [Member] | Derivative Assets (Current) [Member]
Derivatives, Fair Value [Line Items]
Description of Location of Foreign Currency Derivatives on Balance Sheet	Derivativeassets(current)	Derivativeassets(current)
Derivative asset, fair value	4.1	1.2
Not Designated as Hedging Instrument [Member] | Provisional Pricing Arrangements [Member] | Accounts Receivable [Member]
Derivatives, Fair Value [Line Items]
Description of Location of Foreign Currency Derivatives on Balance Sheet	Accountsreceivable	Accountsreceivable
Derivative asset, fair value		83.8
Not Designated as Hedging Instrument [Member] | Provisional Pricing Arrangements [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Description of Location of Foreign Currency Derivatives on Balance Sheet	Othercurrentliabilities	Othercurrentliabilities
Derivative liability, fair value	1.1	19.5