CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (582.1)	$ (330.5)	$ 81.8
Other comprehensive loss, net of reclassifications:
Net (loss) gain on derivative instruments (net of tax effect of ($1.1), $0.6, and ($0.7))	(1.1)	(27.1)	39.3
Change in net unrealized gain (loss) on available-for-sale securities (net of tax effect of ($0.5), $0.0, and ($0.2))	1.3	(1.4)	(0.2)
Change in defined benefit pension items (net of tax effect of ($0.9), $0.9, and $1.8)	(5.5)	(4.6)	(16.0)
Net change in cumulative foreign currency translation loss (net of tax effect of $0.2, $0.5, and $4.9)	(52.1)	(34.7)	(75.8)
Total other comprehensive loss	(57.4)	(67.8)	(52.7)
Total comprehensive (loss) income	$ (639.5)	$ (398.3)	$ 29.1