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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
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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 |  |

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- Definition Margin Already Posted, Aggregate Fair Value + References No definition available. + Details
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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 + Details
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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 + Details
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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 + Details
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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. + Details
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