(Derivatives Pretax Amounts Affecting Income and Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Derivatives in Cash Flow Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified into Income from Accumulated OCI (Effective Portion)	$ 11.7	$ (15.5)
Gain (Loss) Recognized in Accumulated OCI (Effective Portion)	10.7	(9.8)
Net Investment Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Accumulated OCI (Effective Portion)	254.2	(404.5)
Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing and Ineffective Portion)	2.5	0.0
Derivatives Not Designated as Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments, gain (loss) recognized in income, net	29.7	(13.1)
Foreign Exchange [Member] \| Derivatives in Cash Flow Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified into Income from Accumulated OCI (Effective Portion)	12.0	(15.3)
Gain (Loss) Recognized in Accumulated OCI (Effective Portion)	10.7	(9.8)
Foreign Exchange [Member] \| Derivatives Not Designated as Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments, gain (loss) recognized in income, net	(5.6)	3.2
Foreign Exchange Forward [Member] \| Net Investment Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Accumulated OCI (Effective Portion)	9.0	0.0
Cross Currency Interest Rate Contract [Member] \| Net Investment Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing and Ineffective Portion)	2.5	0.0
Interest Rate Contract [Member] \| Derivatives in Cash Flow Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified into Income from Accumulated OCI (Effective Portion)	(0.3)	(0.2)
Gain (Loss) Recognized in Accumulated OCI (Effective Portion)
Other Foreign Currency Denominated Debt [Member] \| Net Investment Hedging Relationships
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Accumulated OCI (Effective Portion)	245.2	(404.5)
Equity [Member] \| Derivatives Not Designated as Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments, gain (loss) recognized in income, net	$ 35.3	$ (16.3)

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
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-Paragraph 4C
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-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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