CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 40.2	$ (39.4)	$ 16.0	$ (121.8)
Other comprehensive income (loss), net of reclassifications:
Net (loss) gain on derivative instruments (net of tax effect of ($1.7), ($1.1), ($2.0) and ($1.8), respectively)	(4.3)		(1.0)
Net (loss) gain on derivative instruments (net of tax effect of ($1.7), ($1.1), ($2.0) and ($1.8), respectively)		11.6		17.6
Change in net unrealized (loss) gain on available-for-sale debt securities (net of tax effect of $0.1, ($0.1), ($0.3) and $0.0, respectively)	(0.2)	(1.3)	0.9	(0.7)
Change in defined benefit pension items (net of tax effect of $0.4, ($0.1), $0.5 and ($1.5), respectively)	(1.8)	2.3	(2.4)	10.0
Net change in cumulative foreign currency translation loss (net of tax effect of ($0.4), $0.2, $0.0 and $0.5, respectively)	(22.8)	(29.7)	(33.2)	(54.0)
Total other comprehensive loss	(29.1)	(17.1)	(35.7)	(27.1)
Total comprehensive income (loss)	$ 11.1	$ (56.5)	$ (19.7)	$ (148.9)