Segments Concerning the Operations Of Reportable Segments (Details) $ in Millions		3 Months Ended		6 Months Ended
		Jul. 31, 2015 USD ($)	Jul. 31, 2014 USD ($)	Jul. 31, 2015 USD ($) segment product_group	Jul. 31, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment				4
Net revenue		$ 609.5	$ 637.1	$ 1,256.0	$ 1,229.6
Gross profit		516.5	549.2	1,071.2	1,063.0
Segments
Segment Reporting Information [Line Items]
Net revenue		609.5	637.1	1,256.0	1,229.6
Unallocated
Segment Reporting Information [Line Items]
Gross profit	[1]	(14.4)	(15.9)	(30.8)	(30.4)
Architecture, Engineering and Construction | Segments
Segment Reporting Information [Line Items]
Net revenue		233.4	217.9	470.1	413.4
Gross profit		209.5	196.1	426.5	371.7
Manufacturing | Segments
Segment Reporting Information [Line Items]
Net revenue		171.2	168.2	355.8	315.5
Gross profit		151.2	151.5	309.3	284.2
Platform Solutions and Emerging Business | Segments
Segment Reporting Information [Line Items]
Net revenue		164.1	207.5	349.4	419.4
Gross profit		138.5	185.3	$ 301.8	376.3
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		40.8	43.5	$ 80.7	81.3
Gross profit		$ 31.7	$ 32.2	$ 64.4	$ 61.2

[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.