Financial Instruments (Effect of Risk-Management Instruments) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Designated as Hedging Instrument \| Effect from hedged fixed-rate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effect from hedged fixed-rate debt	$ (19.6)	$ (4.0)	$ (94.1)	$ 3.6
Designated as Hedging Instrument \| Effect from interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effect from interest rate contracts	19.6	4.0	94.1	(3.6)
Effective portion of losses on interest rate contracts reclassified from accumulated other comprehensive loss	3.7	3.7	11.1	11.1
Not Designated as Hedging Instrument \| Foreign currency exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net losses on foreign currency exchange contracts not designated as hedging instruments	0.7	16.3	76.5	79.2
Net investment hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss)	(47.8)	(58.7)	53.0	(332.0)
Net investment hedges \| Cross-currency interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss)	14.7	(38.2)	52.3	(95.8)
Cash Flow Hedging \| Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss)	$ 0.0	$ 0.0	$ 0.0	$ 13.0

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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-Publisher FASB
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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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- Definition

The effective portion of loss reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of gain (loss) recognized in earnings in the period from the increase (decrease) in fair value of foreign currency derivatives not designated as hedging instruments.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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