Financial Instruments (Effect of Risk-Management Instruments) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Cash flow hedges:
Total	$ (30.3)	$ (20.6)	$ (44.9)	$ 3.7
Foreign currency-denominated notes
Cash flow hedges:
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss), net investment hedges	(72.4)	(30.4)	(5.0)	23.3
Cross-currency interest rate swaps
Cash flow hedges:
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss), net investment hedges	(60.8)	(4.3)	55.0	34.0
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss), cash flow hedges	4.9	(7.4)	(64.9)	(37.5)
Forward-starting interest rate swaps
Cash flow hedges:
Effective portion of risk-management instruments that was recognized in other comprehensive income (loss), cash flow hedges	38.2	0.0	(331.6)	(11.7)
Designated as Hedging Instrument \| Foreign currency-denominated notes
Fair value hedges:
Effect from hedged fixed-rate debt	7.0	59.3	124.4	98.5
Designated as Hedging Instrument \| Interest rate contracts
Fair value hedges:
Effect from interest rate contracts	(7.0)	(59.3)	(124.4)	(98.5)
Cash flow hedges:
Effective portion of losses on interest rate contracts reclassified from accumulated other comprehensive loss	4.1	4.0	8.1	7.8
Designated as Hedging Instrument \| Cross-currency interest rate swaps
Cash flow hedges:
Effective portion of losses on interest rate contracts reclassified from accumulated other comprehensive loss	(11.5)	(16.1)	(24.4)	(44.5)
Not Designated as Hedging Instrument \| Foreign currency exchange contracts
Cash flow hedges:
Net (gains) losses on foreign currency exchange contracts not designated as hedging instruments	$ (22.9)	$ (8.5)	$ (28.6)	$ 40.4

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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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 and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount, before tax and reclassification, of gain (loss) from derivative designated and qualifying as net investment hedge.

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