Segments Concerning the Operations Of Reportable Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2013		Jan. 31, 2012		Jan. 31, 2011
Revenue, Net	$ 606.9	$ 548.0	$ 568.7	$ 588.6	$ 592.4	$ 548.6	$ 546.3	$ 528.3	$ 2,312.2		$ 2,215.6		$ 1,951.8
Gross Profit	544.9	490.1	508.9	529.8	534.9	489.0	488.9	473.7	2,073.7		1,986.5		1,755.2
Depreciation and Amortization									127.8		115.5		105.4
Platform Solutions and Emerging Business
Revenue, Net									849.7		833.1		716.2
Gross Profit									795.2		788.0		678.9
Depreciation and Amortization									1.8		1.8		3.0
Architecture, Engineering And Construction
Revenue, Net									694.3		626.4		568.0
Gross Profit									635.4		569.7		517.6
Depreciation and Amortization									0.2		0.7		1.6
Manufacturing
Revenue, Net									573.8		540.3		470.0
Gross Profit									531.4		496.1		439.5
Depreciation and Amortization									0.5		1.7		2.3
Media and Entertainment
Revenue, Net									194.4		215.8		197.6
Gross Profit									156.6		174.6		153.9
Depreciation and Amortization									0.4		0.5		1.1
Unallocated Amount to Segment
Gross Profit									(44.9)	[1]	(41.9)	[1]	(34.7)	[1]
Depreciation and Amortization									$ 124.9		$ 110.8		$ 97.4

[1] Unallocated amounts primarily relate to corporate expenses and other costs and expenses that are managed outside the reportable segments, including stock-based compensation expense.