Segments Concerning the Operations Of Reportable Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2015 USD ($)	Oct. 31, 2014 USD ($)	Oct. 31, 2015 USD ($) segment product_group		Oct. 31, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Net revenue	$ 599.8	$ 618.0	$ 1,855.8		$ 1,847.6
Gross profit	508.8	532.0	1,580.0		1,595.0
Segments
Segment Reporting Information [Line Items]
Net revenue	599.8	618.0	1,855.8		1,847.6
Unallocated
Segment Reporting Information [Line Items]
Gross profit	(14.8)	(14.5)	(45.6)	[1]	(44.9)	[1]
Architecture, Engineering and Construction | Segments
Segment Reporting Information [Line Items]
Net revenue	224.9	217.1	695.0		630.5
Gross profit	202.0	194.3	628.5		566.0
Manufacturing | Segments
Segment Reporting Information [Line Items]
Net revenue	174.9	169.7	530.7		485.2
Gross profit	155.2	152.8	464.5		437.0
Platform Solutions and Emerging Business | Segments
Segment Reporting Information [Line Items]
Net revenue	160.9	188.4	510.3		607.8
Gross profit	135.9	167.3	$ 437.7		543.6
Media and Entertainment
Segment Reporting Information [Line Items]
Number of product groups | product_group			2
Media and Entertainment | Segments
Segment Reporting Information [Line Items]
Net revenue	39.1	42.8	$ 119.8		124.1
Gross profit	$ 30.5	$ 32.1	$ 94.9		$ 93.3

[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.