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Derivative Contracts - Fair Value of Derivative Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Mar. 31, 2019
Not Designated as Hedging Instrument | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 1,402.3	$ 1,696.3
Cash collateral	3.4	2.9
Not Designated as Hedging Instrument | Interest rate swap
Derivatives, Fair Value [Line Items]
Initial and variation margin, posted	0.0	111.1
Not Designated as Hedging Instrument | Derivatives at Fair Value | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair Value	21.5	8.1
Derivative, Notional Amount	803.1	687.3
Not Designated as Hedging Instrument | Liabilities Under Derivative Contracts | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair Value	(13.6)	(8.9)
Derivative, Notional Amount	599.2	1,009.0
Not Designated as Hedging Instrument | Liabilities Under Derivative Contracts | Interest rate swap
Derivatives, Fair Value [Line Items]
Fair Value	0.0	(78.3)
Derivative, Notional Amount	0.0	1,800.0	$ 1,800.0	$ 3,138.0
Designated as Hedging Instrument | Derivatives at Fair Value | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair Value	5.3	4.8
Derivative, Notional Amount	$ 90.6	$ 85.5

X

- Definition

Margin Already Posted, Aggregate Fair Value

+ References

No definition available.

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- 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=117331979&loc=d3e41228-113958

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

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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.

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