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Derivative Contracts - Fair Value of Derivative Instruments (Details) - Foreign Exchange Contracts - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Notional Amount	$ 1,257.3	$ 751.6
Cash collateral	2.3	0.6
Not Designated as Hedging Instrument | Derivatives at Fair Value
Derivatives, Fair Value [Line Items]
Notional Amount	496.5	577.7
Fair Value	14.6	5.0
Not Designated as Hedging Instrument | Liabilities Under Derivative Contracts
Derivatives, Fair Value [Line Items]
Notional Amount	760.8	173.9
Fair Value	(13.9)	(1.0)
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Cash collateral	0.0	0.0
Designated as Hedging Instrument | Derivatives at Fair Value
Derivatives, Fair Value [Line Items]
Notional Amount	0.0	60.6
Fair Value	0.0	1.4
Designated as Hedging Instrument | Liabilities Under Derivative Contracts
Derivatives, Fair Value [Line Items]
Notional Amount	94.3	0.0
Fair Value	$ (1.2)	$ 0.0

X

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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X

- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959

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- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

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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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