Derivative Instruments | Derivatives not Designated as Hedges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ (1.0)	$ 1.3	$ (0.3)	$ 0.6
Cost of Sales [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	2.1	5.4	3.0	12.0
Nonoperating Income (Expense) [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ (3.1)	$ (4.1)	$ (3.3)	$ (11.4)