Financial Instruments (Derivative Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
Apr. 30, 2019	Jan. 31, 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net gain expected to be recognized in next 12 months	$ 18.3
Minimum \| Foreign currency contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative instrument, term	1 month
Maximum \| Foreign currency contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative instrument, term	12 months
Designated as hedging instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 938.6	$ 803.5
Derivatives not designated as hedging instruments \| Foreign currency contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 336.3	$ 579.8

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

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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- 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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- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994

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