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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	9 Months Ended
		Sep. 30, 2018	Sep. 30, 2018
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income		$ (4.0)	$ (3.7)
Interest Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings from Excluded Components	[1]	0.5	0.5
Forward contracts
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income		(5.9)	(5.6)
Forward contracts | Interest Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings from Excluded Components	[1]	0.5	0.5
Put option
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income		1.6	1.6
Put option | Interest Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings from Excluded Components	[1]	0.0	0.0
Call option
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income		0.3	0.3
Call option | Interest Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings from Excluded Components	[1]	$ 0.0	$ 0.0
[1] The excluded components are recorded as a reduction in Interest expense.

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

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.

+ References

No definition available.

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- Definition

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
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998896-113959

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580

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