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Derivative Contracts - Fair Value of Derivative Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	May 09, 2016
Not Designated as Hedging Instrument | Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Notional Amount	$ 751.6	$ 665.6
Cash collateral	0.6	0.0
Not Designated as Hedging Instrument | Derivatives at Fair Value | Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Notional Amount	577.7	240.2
Fair Value	5.0	5.0
Not Designated as Hedging Instrument | Liabilities Under Derivative Contracts [Member] | Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Notional Amount	173.9	425.4
Fair Value	(1.0)	(17.7)
Designated as Hedging Instrument | Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Cash collateral	0.0	2.2
Designated as Hedging Instrument | Derivatives at Fair Value | Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Notional Amount	60.6	0.0
Fair Value	1.4	2.2
Designated as Hedging Instrument | Liabilities Under Derivative Contracts [Member] | Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Notional Amount	0.0	108.6
Fair Value	$ 0.0	$ (0.7)
Goldman Sachs International
Derivatives, Fair Value [Line Items]
Notional Amount			$ 256.3

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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624258-113959

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X

- 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://www.xbrl.org/2003/role/presentationRef
-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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