CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Statement of Comprehensive Income [Abstract]
Net gain on derivative instruments, tax effect	$ 2.3	$ (1.7)	$ 1.9	$ (2.0)
Change in net unrealized gain on available-for-sale debt securities, tax effect	0.0	0.1	0.1	(0.3)
Change in defined benefit pension items, tax effect	0.0	0.4	0.0	0.5
Net change in cumulative foreign currency translation loss, tax effect	$ (0.4)	$ (0.4)	$ (0.4)	$ 0.0

Amount of tax expense (benefit), before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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Amount, after adjustment, of tax expense (benefit) for unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and tax expense (benefit) for unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.

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Amount, after reclassification, of tax expense (benefit) for gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

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