CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions		3 Months Ended
		Apr. 30, 2017	Apr. 30, 2016
Statement of Comprehensive Income [Abstract]
Net loss		$ (129.6)	$ (167.7)
Other comprehensive income (loss), net of reclassifications:
Net loss on derivative instruments (net of tax effect of $0.5 and ($1.9), respectively)		(1.4)	(9.5)
Change in net unrealized gain on available-for-sale securities (net of tax effect of ($0.3) and ($0.5), respectively)		0.7	2.3
Change in defined benefit pension items (1)	[1]	(0.5)	0.3
Net change in cumulative foreign currency translation gain (net of tax effect of ($0.3) and $0.0, respectively)		13.4	6.5
Total other comprehensive income (loss)		12.2	(0.4)
Total comprehensive loss		$ (117.4)	$ (168.1)

[1] Tax effects related to defined benefit pension items were immaterial for each of the periods presented.