Business and Summary of Significant Accounting Policies - Changes In the Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Accounting Policies [Abstract]
Impairment of long-lived assets	$ 0.0	$ 0.0	$ 0.0
Goodwill [Roll Forward]
Goodwill, beginning of period, gross	1,684.2	1,605.4
Less: accumulated impairment losses, beginning of the year	(149.2)	(149.2)
Additions arising from acquisitions during the year (1)	62.8	97.3
Effect of foreign currency translation, measurement period adjustments, and other (2)	(36.7)	(18.5)
Goodwill, end of period, net	$ 1,561.1	$ 1,535.0