Business and Summary of Significant Accounting Policies Changes In the Carrying Amount of Goodwill (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 31, 2012	Jan. 31, 2011
Goodwill [Roll Forward]
Goodwill before accumulated impairments	$ 703.3	$ 692.1
Accumulated impairment losses	(149.2)	(149.2)
Goodwill	554.1	542.9
Goodwill, Acquired During Period		10.1
Goodwill, Translation and Purchase Accounting Adjustments	(1.8)	1.1
Goodwill before accumulated impairments	831.6	703.3
Accumulated impairment losses	(149.2)	(149.2)
Goodwill	682.4	554.1
Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill before accumulated impairments	45.3	40.2
Accumulated impairment losses	0	0
Goodwill	45.3	40.2
Goodwill, Acquired During Period		4.6
Goodwill, Translation and Purchase Accounting Adjustments	(0.7)	0.5
Goodwill before accumulated impairments	76.6	45.3
Accumulated impairment losses	0	0
Goodwill	76.6	45.3
Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill before accumulated impairments	224.2	224.8
Accumulated impairment losses	0	0
Goodwill	224.2	224.8
Goodwill, Acquired During Period		0
Goodwill, Translation and Purchase Accounting Adjustments	(1.2)	(0.6)
Goodwill before accumulated impairments	247.7	224.2
Accumulated impairment losses	0	0
Goodwill	247.7	224.2
Manufacturing
Goodwill [Roll Forward]
Goodwill before accumulated impairments	279.1	277.9
Accumulated impairment losses	0	0
Goodwill	279.1	277.9
Goodwill, Acquired During Period		0
Goodwill, Translation and Purchase Accounting Adjustments	0.1	1.2
Goodwill before accumulated impairments	323.3	279.1
Accumulated impairment losses	0	0
Goodwill	323.3	279.1
Media and Entertainment
Goodwill [Roll Forward]
Goodwill before accumulated impairments	154.7	149.2
Accumulated impairment losses	(149.2)	(149.2)
Goodwill	5.5	0
Goodwill, Acquired During Period		5.5
Goodwill, Translation and Purchase Accounting Adjustments	0	0
Goodwill before accumulated impairments	184.0	154.7
Accumulated impairment losses	(149.2)	(149.2)
Goodwill	34.8	5.5
Scaleform Corporation
Goodwill [Roll Forward]
Goodwill, Acquired During Period	22.6
Scaleform Corporation | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Scaleform Corporation | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Scaleform Corporation | Manufacturing
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Scaleform Corporation | Media and Entertainment
Goodwill [Roll Forward]
Goodwill, Acquired During Period	22.6
Blue Ridge Numerics, Inc
Goodwill [Roll Forward]
Goodwill, Acquired During Period	22.3
Blue Ridge Numerics, Inc | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Blue Ridge Numerics, Inc | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Blue Ridge Numerics, Inc | Manufacturing
Goodwill [Roll Forward]
Goodwill, Acquired During Period	22.3
Blue Ridge Numerics, Inc | Media and Entertainment
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Instructables Corporation
Goodwill [Roll Forward]
Goodwill, Acquired During Period	24.4
Instructables Corporation | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill, Acquired During Period	24.4
Instructables Corporation | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Instructables Corporation | Manufacturing
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Instructables Corporation | Media and Entertainment
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Micro Application Packages Limited
Goodwill [Roll Forward]
Goodwill, Acquired During Period	12.7
Micro Application Packages Limited | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Micro Application Packages Limited | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill, Acquired During Period	12.7
Micro Application Packages Limited | Manufacturing
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Micro Application Packages Limited | Media and Entertainment
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
T-splines
Goodwill [Roll Forward]
Goodwill, Acquired During Period	19.8
T-splines | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
T-splines | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
T-splines | Manufacturing
Goodwill [Roll Forward]
Goodwill, Acquired During Period	19.8
T-splines | Media and Entertainment
Goodwill [Roll Forward]
Goodwill, Acquired During Period	0
Other Acquisitions
Goodwill [Roll Forward]
Goodwill, Acquired During Period	28.3
Other Acquisitions | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill, Acquired During Period	7.6
Other Acquisitions | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill, Acquired During Period	12.0
Other Acquisitions | Manufacturing
Goodwill [Roll Forward]
Goodwill, Acquired During Period	2.0
Other Acquisitions | Media and Entertainment
Goodwill [Roll Forward]
Goodwill, Acquired During Period	$ 6.7