CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
Statement of Comprehensive Income [Abstract]
Net gain (loss) on derivative instruments - tax effect	$ 0.0	$ 0.5	$ (0.7)	$ (0.6)
Change in net unrealized loss on available-for-sale securities, tax effect	0.0	0.7	0.2	0.7
Net change in cumulative foreign currency translation (loss) gain, tax effect	$ (4.5)	$ 3.4	$ 0.0	$ 2.9