Goodwill Changes in the Carrying Amount of Goodwill (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Apr. 30, 2012 ReportingUnits
Goodwill [Line Items]
Goodwill before accumulated impairment losses beginning balance	$ 831.6
Accumulated impairment losses beginning balance	(149.2)
Goodwill	682.4
Effect of foreign currency translation, purchase accounting and other	0.5
Goodwill before accumulated impairment losses ending balance	832.1
Accumulated impairment losses ending balance	(149.2)
Goodwill	682.9
Number of reporting units (presented as an integer)	4
Platform Solutions and Emerging Business
Goodwill [Line Items]
Goodwill before accumulated impairment losses beginning balance	76.6
Accumulated impairment losses beginning balance	0
Goodwill	76.6
Effect of foreign currency translation, purchase accounting and other	0.1
Goodwill before accumulated impairment losses ending balance	76.7
Accumulated impairment losses ending balance	0
Goodwill	76.7
Architecture, Engineering and Construction
Goodwill [Line Items]
Goodwill before accumulated impairment losses beginning balance	247.7
Accumulated impairment losses beginning balance	0
Goodwill	247.7
Effect of foreign currency translation, purchase accounting and other	0.8
Goodwill before accumulated impairment losses ending balance	248.5
Accumulated impairment losses ending balance	0
Goodwill	248.5
Manufacturing
Goodwill [Line Items]
Goodwill before accumulated impairment losses beginning balance	323.3
Accumulated impairment losses beginning balance	0
Goodwill	323.3
Effect of foreign currency translation, purchase accounting and other	(0.4)
Goodwill before accumulated impairment losses ending balance	322.9
Accumulated impairment losses ending balance	0
Goodwill	322.9
Media and Entertainment
Goodwill [Line Items]
Goodwill before accumulated impairment losses beginning balance	184.0
Accumulated impairment losses beginning balance	(149.2)
Goodwill	34.8
Effect of foreign currency translation, purchase accounting and other	0
Goodwill before accumulated impairment losses ending balance	184.0
Accumulated impairment losses ending balance	(149.2)
Goodwill	$ 34.8