Financial Instruments (Effect of Risk Management) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flow Hedge [Abstract]
Total	$ 114.8	$ 112.7	$ 93.8
Cash flow hedges: \| Interest rate swap
Cash Flow Hedge [Abstract]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is	0.0	13.0	(3.4)
Net investment hedges:
Cash Flow Hedge [Abstract]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is	110.4	(361.5)	137.5
Net investment hedges: \| Foreign Exchange Contract
Cash Flow Hedge [Abstract]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is	5.7	0.0	31.9
Net investment hedges: \| Cross-currency interest rate swaps
Cash Flow Hedge [Abstract]
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss) is	96.8	(126.6)	32.5
Designated as Hedging Instrument \| Hedged Fixed Rate Debt
Fair Value Hedge [Abstract]
Effect from hedged fixed-rate debt	(40.9)	(14.1)	(30.8)
Designated as Hedging Instrument \| Interest Rate Contract
Fair Value Hedge [Abstract]
Effect from interest rate contracts	40.9	14.1	30.8
Cash Flow Hedge [Abstract]
Effective portion of losses on interest rate contracts reclassified from accumulated other comprehensive loss	14.8	14.8	15.0
Not Designated as Hedging Instrument \| Foreign Exchange Contract
Cash Flow Hedge [Abstract]
Net losses on foreign currency exchange contracts not designated as hedging instruments	$ 100.0	$ 97.9	$ 78.8

Cash Flow Hedge [Abstract]

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Derivative Instruments, Gain(loss) Recognized

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Fair Value Hedge [Abstract]

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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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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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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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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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