Goodwill Changes in the Carrying Amount of Goodwill (Details) $ in Millions		6 Months Ended
		Jul. 31, 2015 USD ($)
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		$ 1,605.4
Accumulated impairment losses		(149.2)
Goodwill		1,456.2
Effect of foreign currency translation, purchase accounting adjustments, and other		(5.8)
Goodwill before accumulated impairment losses ending balance		1,623.0
Accumulated impairment losses		(149.2)
Goodwill		1,473.8
Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		327.5
Accumulated impairment losses		0.0
Goodwill		327.5
Effect of foreign currency translation, purchase accounting adjustments, and other		1.3
Goodwill before accumulated impairment losses ending balance		338.4
Accumulated impairment losses		0.0
Goodwill		338.4
Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		427.0
Accumulated impairment losses		0.0
Goodwill		427.0
Effect of foreign currency translation, purchase accounting adjustments, and other		(1.9)
Goodwill before accumulated impairment losses ending balance		428.5
Accumulated impairment losses		0.0
Goodwill		428.5
Manufacturing
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		422.7
Accumulated impairment losses		0.0
Goodwill		422.7
Effect of foreign currency translation, purchase accounting adjustments, and other		(1.4)
Goodwill before accumulated impairment losses ending balance		421.3
Accumulated impairment losses		0.0
Goodwill		421.3
Media and Entertainment
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance		245.2
Accumulated impairment losses		(149.2)
Goodwill		96.0
Effect of foreign currency translation, purchase accounting adjustments, and other		0.1
Goodwill before accumulated impairment losses ending balance		255.7
Accumulated impairment losses		(149.2)
Goodwill		106.5
Delcam
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance	[1]	183.0
Accumulated impairment losses	[1]	0.0
Goodwill	[1]	183.0
Effect of foreign currency translation, purchase accounting adjustments, and other	[1]	(3.9)
Goodwill before accumulated impairment losses ending balance	[1]	179.1
Accumulated impairment losses	[1]	0.0
Goodwill	[1]	179.1
Other
Goodwill [Roll Forward]
Addition arising from other acquisitions		23.4
Goodwill		23.4
Other | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Addition arising from other acquisitions		9.6
Other | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Addition arising from other acquisitions		3.4
Other | Manufacturing
Goodwill [Roll Forward]
Addition arising from other acquisitions		0.0
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.