Goodwill and Long-lived Assets, Net (Changes in Carrying Amount of Goodwill) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2015	Oct. 31, 2015	Jan. 31, 2017	Jan. 31, 2016	Dec. 31, 2014
Goodwill and Long-Lived Assets, Net
Goodwill, Balance	$ 1,328.7		$ 954.9	$ 1,286.5
Acquisitions			50.8	2.5
Goodwill, purchase price adjustment	(21.7)		(2.5)	(10.3)
Effect of foreign currency translation	(20.5)		(6.8)	(13.4)
Impairment	0.0	$ (310.4)	0.0	(310.4)	$ 0.0
Goodwill, Balance	$ 1,286.5		$ 996.4	$ 954.9	$ 1,328.7