CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (144.0)	$ (98.2)	$ (273.6)	$ (265.9)
Other comprehensive income (loss), net of reclassifications:
Net loss on derivative instruments (net of tax effect of $0.9, $1.1, $1.4 and ($0.8), respectively)	(11.6)	(1.5)	(13.0)	(11.0)
Change in net unrealized (loss) gain on available-for-sale securities (net of tax effect of $0.4, ($0.1), $0.1, and ($0.6), respectively)	(0.5)	1.1	0.2	3.4
Change in defined benefit pension items (net of tax effect of $0.0, ($0.2), $0.0, and ($0.2), respectively)	0.3	0.0	(0.2)	0.3
Net change in cumulative foreign currency translation gain (loss) (net of tax effect of ($0.6), $0.0, ($0.9) and $0.0, respectively)	25.2	(7.9)	38.6	(1.4)
Total other comprehensive income (loss)	13.4	(8.3)	25.6	(8.7)
Total comprehensive loss	$ (130.6)	$ (106.5)	$ (248.0)	$ (274.6)