Goodwill Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Millions		9 Months Ended
		Oct. 31, 2015	Jan. 31, 2015
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		$ 1,605.4
Accumulated impairment losses		(149.2)	$ (149.2)
Goodwill		1,515.0	1,456.2
Effect of foreign currency translation, purchase accounting adjustments, and other		(4.6)
Goodwill before accumulated impairment losses ending balance		1,664.2
Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		327.5
Accumulated impairment losses		0.0	0.0
Goodwill		359.2	327.5
Effect of foreign currency translation, purchase accounting adjustments, and other		(0.5)
Goodwill before accumulated impairment losses ending balance		359.2
Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		427.0
Accumulated impairment losses		0.0	0.0
Goodwill		429.2	427.0
Effect of foreign currency translation, purchase accounting adjustments, and other		(2.0)
Goodwill before accumulated impairment losses ending balance		429.2
Manufacturing
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		422.7
Accumulated impairment losses		0.0	0.0
Goodwill		438.1	422.7
Effect of foreign currency translation, purchase accounting adjustments, and other		(1.2)
Goodwill before accumulated impairment losses ending balance		438.1
Media and Entertainment
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		245.2
Accumulated impairment losses		(149.2)	(149.2)
Goodwill		106.5	96.0
Effect of foreign currency translation, purchase accounting adjustments, and other		0.1
Goodwill before accumulated impairment losses ending balance		255.7
Delcam
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance	[1]	183.0
Accumulated impairment losses	[1]	0.0	0.0
Goodwill	[1]	182.0	$ 183.0
Effect of foreign currency translation, purchase accounting adjustments, and other	[1]	(1.0)
Goodwill before accumulated impairment losses ending balance	[1]	182.0
Other
Goodwill [Roll Forward]
Goodwill		63.4
Addition arising from other acquisitions		63.4
Other | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Addition arising from other acquisitions		32.2
Other | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Addition arising from other acquisitions		4.2
Other | Manufacturing
Goodwill [Roll Forward]
Addition arising from other acquisitions		16.6
Other | Media and Entertainment
Goodwill [Roll Forward]
Addition arising from other acquisitions		10.4
Other | Delcam
Goodwill [Roll Forward]
Addition arising from other acquisitions	[1]	$ 0.0

[1] Delcam is a separate reporting unit within our Manufacturing ("MFG") operating segment.