Interest and Other Expense, net (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Interest and Other Income, net [Abstract]
Interest and investment expense, net	$ (33.9)	$ (13.2)	$ (9.8)
(Loss) gain on foreign currency	0.0	(3.9)	4.0
Gain (loss) on strategic investments	3.8	(23.3)	(1.8)
Other income	8.5	2.7	2.7
Interest and other expense, net	$ (21.6)	$ (37.7)	$ (4.9)