Derivatives - Schedules of Location and Amount of Gains/(Losses) from Hedging Activities (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Revenues	$ 1,387.8	$ 1,404.7	$ 4,188.3	$ 4,086.0
Interest Expense	(38.4)	(37.2)	(111.4)	(104.2)
Other income, net	0.6	2.9	13.1	9.4
Hedges [Abstract]
Gain/(Loss) Recognized in OCI on Derivatives	3.3	(21.2)	22.8	(68.4)
Undesignated hedges
Hedges [Abstract]
Gain/(Loss) Recognized in Income on Derivatives	9.3	(4.3)	44.2	(27.1)
Undesignated hedges \| Selling, general and administrative
Hedges [Abstract]
Gain/(Loss) Recognized in Income on Derivatives	8.9	(4.0)	44.1	(26.3)
Undesignated hedges \| Revenues
Hedges [Abstract]
Gain/(Loss) Recognized in Income on Derivatives	0.4	0.0	2.0	0.0
Undesignated hedges \| Other Income, net
Hedges [Abstract]
Gain/(Loss) Recognized in Income on Derivatives	0.0	(0.3)	(1.9)	(0.8)
Fair Value Hedges \| Interest rate contracts \| Interest expense
Hedges [Abstract]
Hedged items	(0.1)	0.2	1.3	2.6
Derivatives designated as hedging instruments	(0.3)	(0.2)	(2.3)	(0.7)
Fair Value Hedges \| Interest rate contracts \| Revenues
Hedges [Abstract]
Hedged items	0.0	0.0	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0	0.0	0.0
Fair Value Hedges \| Interest rate contracts \| Other Income, net
Hedges [Abstract]
Hedged items	0.0	0.0	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0	0.0	0.0
Cash Flow Hedges \| Foreign currency contracts
Hedges [Abstract]
Gain/(Loss) Recognized in OCI on Derivatives	3.3	(21.2)	22.8	(68.4)
Cash Flow Hedges \| Foreign currency contracts \| Interest expense
Hedges [Abstract]
Amount of gain/(loss) reclassified from accumulated other comprehensive loss into income	0.0	0.0	0.0	0.0
Amount excluded from effectiveness testing recognized in earnings based on an amortization approach	0.0	0.0	0.0	0.0
Amount excluded from effectiveness testing recognized in earnings based on changes in fair value	0.0	0.0	0.0	0.0
Amount of gain/(loss) reclassified from accumulated other comprehensive loss into income as a result that a forecasted transaction is no longer probable of occurring	0.0	0.0	0.0	0.0
Cash Flow Hedges \| Foreign currency contracts \| Revenues
Hedges [Abstract]
Amount of gain/(loss) reclassified from accumulated other comprehensive loss into income	0.2	(2.2)	(14.6)	11.3
Amount excluded from effectiveness testing recognized in earnings based on an amortization approach	1.3	0.0	2.3	0.0
Amount excluded from effectiveness testing recognized in earnings based on changes in fair value	1.9	0.0	5.7	0.0
Amount of gain/(loss) reclassified from accumulated other comprehensive loss into income as a result that a forecasted transaction is no longer probable of occurring	0.0	0.0	0.0	0.0
Cash Flow Hedges \| Foreign currency contracts \| Other Income, net
Hedges [Abstract]
Amount of gain/(loss) reclassified from accumulated other comprehensive loss into income	0.0	0.0	0.0	0.0
Amount excluded from effectiveness testing recognized in earnings based on an amortization approach	0.0	0.0	0.0	0.0
Amount excluded from effectiveness testing recognized in earnings based on changes in fair value	0.0	2.3	0.0	7.6
Amount of gain/(loss) reclassified from accumulated other comprehensive loss into income as a result that a forecasted transaction is no longer probable of occurring	$ 0.0	$ 0.0	$ 0.0	$ 0.0

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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

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The amount of net gain (loss) reclassified into earnings when foreign currency cash flow hedge is discontinued because it is probable that the original forecasted transactions will not occur by the end of the original period or an additional two month time period.

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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 of unrealized gain (loss) included in earnings related to the fair value of the hedged item in an interest rate fair value hedge, offset by the gain (loss) on the hedging instrument to the extent that the fair value hedge is determined to be effective.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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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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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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