Goodwill Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2016	Jan. 31, 2016
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance	$ 1,684.2
Accumulated impairment losses	(149.2)	$ (149.2)
Goodwill	1,580.5	1,535.0
Effect of foreign currency translation, purchase accounting adjustments, and other	0.1
Goodwill before accumulated impairment losses ending balance	1,729.7
Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance	386.9
Accumulated impairment losses	0.0	0.0
Goodwill	393.2	386.9
Effect of foreign currency translation, purchase accounting adjustments, and other	6.3
Goodwill before accumulated impairment losses ending balance	393.2
Architecture, Engineering and Construction
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance	427.2
Accumulated impairment losses	0.0	0.0
Goodwill	431.6	427.2
Effect of foreign currency translation, purchase accounting adjustments, and other	4.4
Goodwill before accumulated impairment losses ending balance	431.6
Manufacturing
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance	613.9
Accumulated impairment losses	0.0	0.0
Goodwill	615.6	613.9
Effect of foreign currency translation, purchase accounting adjustments, and other	(11.9)
Goodwill before accumulated impairment losses ending balance	615.6
Media and Entertainment
Goodwill [Roll Forward]
Goodwill before accumulated impairment losses beginning balance	256.2
Accumulated impairment losses	(149.2)	(149.2)
Goodwill	140.1	$ 107.0
Effect of foreign currency translation, purchase accounting adjustments, and other	1.3
Goodwill before accumulated impairment losses ending balance	289.3
Other
Goodwill [Roll Forward]
Goodwill	45.4
Addition arising from other acquisitions	45.4
Other | Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Addition arising from other acquisitions	0.0
Other | Architecture, Engineering and Construction
Goodwill [Roll Forward]
Addition arising from other acquisitions	0.0
Other | Manufacturing
Goodwill [Roll Forward]
Addition arising from other acquisitions	13.6
Other | Media and Entertainment
Goodwill [Roll Forward]
Addition arising from other acquisitions	$ 31.8