Segments Concerning the Operations Of Reportable Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Oct. 31, 2014		Oct. 31, 2013		Oct. 31, 2014 segment		Oct. 31, 2013
Segment Reporting Information [Line Items]
Number of reportable segments					4
Net revenue	$ 618.0		$ 555.2		$ 1,847.6		$ 1,687.3
Gross profit	532.0		488.1		1,595.0		1,484.9
Unallocated
Segment Reporting Information [Line Items]
Gross profit	(14.5)	[1]	(12.2)	[1]	(44.9)	[1]	(36.9)	[1]
Platform Solutions and Emerging Business
Segment Reporting Information [Line Items]
Net revenue	188.4		183.4		607.8		593.4
Gross profit	167.3		165.9		543.6		540.7
Architecture, Engineering and Construction
Segment Reporting Information [Line Items]
Net revenue	217.1		185.9		630.5		535.1
Gross profit	194.3		168.9		566.0		485.0
Manufacturing
Segment Reporting Information [Line Items]
Net revenue	169.7		142.0		485.2		425.1
Gross profit	152.8		130.1		437.0		389.9
Media and Entertainment
Segment Reporting Information [Line Items]
Number of product groups					2
Net revenue	42.8		43.9		124.1		133.7
Gross profit	$ 32.1		$ 35.4		$ 93.3		$ 106.2

[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.