CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (98.2)	$ (268.6)	$ (265.9)	$ (249.5)
Other comprehensive loss, net of reclassifications:
Net (loss) on derivative instruments (net of tax effect of $1.1, $0.8, ($0.8) and ($0.7), respectively)	(1.5)	(4.7)	(11.0)	(10.1)
Change in net unrealized gain (loss) on available-for-sale securities (net of tax effect of ($0.1), $0.3, ($0.6) and $0.2, respectively)	1.1	(1.4)	3.4	(1.2)
Change in defined benefit pension items (net of tax effect of ($0.2), $0.0, ($0.2) and $0.0, respectively)	0.0	0.3	0.3	1.0
Net change in cumulative foreign currency translation loss (net of tax effect of $0.0, $0.7, $0.0 and $4.5, respectively)	(7.9)	(8.5)	(1.4)	(6.7)
Total other comprehensive loss	(8.3)	(14.3)	(8.7)	(17.0)
Total comprehensive loss	$ (106.5)	$ (282.9)	$ (274.6)	$ (266.5)