CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (82.4)	$ (129.6)
Other comprehensive loss (income), net of reclassifications:
Net gain (loss) on derivative instruments (net of tax effect of ($0.7) and $0.5, respectively)	6.0	(1.4)
Change in net unrealized gain on available-for-sale debt securities (net of tax effect of $0.1 and ($0.3), respectively)	0.6	0.7
Change in defined benefit pension items (net of tax effect of ($1.4) and $0.0, respectively)	7.7	(0.5)
Net change in cumulative foreign currency translation (loss) gain (net of tax effect of $0.3 and ($0.3), respectively)	(24.3)	13.4
Total other comprehensive (loss) income	(10.0)	12.2
Total comprehensive loss	$ (92.4)	$ (117.4)