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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 $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income	$ 1.0
Interest Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings from Excluded Components	3.8	[1]
Forward contracts
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income	27.2
Forward contracts | Interest Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings from Excluded Components	3.8	[1]
Put options
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income	(17.8)
Put options | Interest Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings from Excluded Components	0.0	[1]
Call options
Derivative [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income	(8.4)
Call options | Interest Expense
Derivative [Line Items]
Gain (Loss) Recognized in Earnings from Excluded Components	$ 0.0	[1]
[1] The excluded components are recorded as a reduction in Interest expense.

X

- Definition

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

+ References

No definition available.

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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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