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Derivative Financial Instruments - Effect on Statement of Comprehensive Income and Statement of Income (Details) - Designated as Hedging Instrument - Derivatives in Net Investment Hedging Relationship - USD ($) $ in Millions		3 Months Ended	6 Months Ended
		Jun. 30, 2019	Jun. 30, 2019
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income		$ 6.7	$ 0.3
Gain Recognized in Earnings from Excluded Components	[1]	3.5	7.0
Forward contracts
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income		26.6	9.8
Gain Recognized in Earnings from Excluded Components	[1]	3.5	7.0
Put options
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income		(12.3)	5.6
Gain Recognized in Earnings from Excluded Components	[1]	0.0	0.0
Call options
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income		(7.6)	(15.1)
Gain Recognized in Earnings from Excluded Components	[1]	0.0	0.0
Foreign Currency Translation Adjustment
Derivative [Line Items]
Gain Reclassified from Accumulated Other Comprehensive Loss into Earnings		0.3	0.2
Foreign Currency Translation Adjustment | Forward contracts
Derivative [Line Items]
Gain Reclassified from Accumulated Other Comprehensive Loss into Earnings		0.3	0.2
Foreign Currency Translation Adjustment | Put options
Derivative [Line Items]
Gain Reclassified from Accumulated Other Comprehensive Loss into Earnings		0.0	0.0
Foreign Currency Translation Adjustment | Call options
Derivative [Line Items]
Gain Reclassified from Accumulated Other Comprehensive Loss into Earnings		$ 0.0	$ 0.0
[1] The excluded components of the forward contracts are recognized in earnings on a straight-line basis over the respective period of the contracts as a reduction to Interest expense on the Consolidated Statements of Income.

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- Definition

Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Net of Tax

+ References

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
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Amount, after tax, of reclassification from accumulated other comprehensive income (AOCI) of gain (loss) from increase (decrease) in fair value of net investment hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4CCC
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-Publisher FASB
-Name Accounting Standards Codification
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