Other Intangible Assets and Related Accumulated Amortization (Details) - USD ($) $ in Millions		Apr. 30, 2017	Jan. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, at cost	[1]	$ 961.9	$ 959.5
Less: Accumulated amortization		(874.3)	(862.0)
Other intangible assets, net		87.6	97.5
Developed technologies, at cost
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, at cost		584.3	583.6
Customer relationships, trade names, patents, and user lists, at cost
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, at cost	[2]	$ 377.6	$ 375.9

[1] Includes the effects of foreign currency translation.

[2] Included in “Other assets” in the accompanying Condensed Consolidated Balance Sheets.