Acquisitions - Summary of Fair Value of Assets Acquired and Liabilities Assumed by Major Class (Detail) (USD $) In Millions, unless otherwise specified				0 Months Ended					0 Months Ended															0 Months Ended					12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012	Jun. 07, 2012 Vela Systems	Jun. 07, 2012 Vela Systems Developed technologies	Jun. 07, 2012 Vela Systems Customer relationships	Jun. 07, 2012 Vela Systems Trade name	Jun. 07, 2012 Vela Systems User List	Aug. 02, 2012 Socialcam	Aug. 02, 2012 Socialcam Developed technologies	Aug. 02, 2012 Socialcam Customer relationships	Aug. 02, 2012 Socialcam Trade name	Aug. 02, 2012 Socialcam User List	Oct. 04, 2012 Qontext	Oct. 04, 2012 Qontext Developed technologies	Oct. 04, 2012 Qontext Customer relationships	Oct. 04, 2012 Qontext Trade name	Oct. 04, 2012 Qontext User List	Dec. 21, 2012 PI-VR	Dec. 21, 2012 PI-VR Developed technologies	Dec. 21, 2012 PI-VR Customer relationships	Dec. 21, 2012 PI-VR Trade name	Dec. 21, 2012 PI-VR User List	Nov. 21, 2013 Graitec SA	Nov. 21, 2013 Graitec SA Developed technologies	Nov. 21, 2013 Graitec SA Customer relationships	Nov. 21, 2013 Graitec SA Trade name	Nov. 21, 2013 Graitec SA User List	Jan. 31, 2014 Other	Jan. 31, 2013 Other	Jan. 31, 2014 Other Developed technologies	Jan. 31, 2013 Other Developed technologies	Jan. 31, 2014 Other Customer relationships	Jan. 31, 2013 Other Customer relationships	Jan. 31, 2014 Other Trade name	Jan. 31, 2013 Other Trade name	Jan. 31, 2014 Other User List	Jan. 31, 2013 Other User List
Business Acquisition [Line Items]
Intangible assets					$ 5.9	$ 3.6	$ 2.6	$ 0		$ 1.9	$ 0	$ 5.3	$ 22.3		$ 2.0	$ 0	$ 0	$ 0		$ 7.6	$ 6.7	$ 1.9	$ 0		$ 15.9	$ 2.2	$ 1.7	$ 0			$ 15.9	$ 13.6	$ 2.8	$ 1.5	$ 1.8	$ 2.0	$ 0	$ 0
Goodwill	1,009.9	871.5	682.4	57.5					23.0					24.0					36.8					73.4					67.0	46.1
Deferred Revenue				(2.0)					0					0					(0.1)					0					0	0
Deferred tax asset (liability)				3.9					(9.4)					0					(5.0)					(6.2)					0.7	0
Net tangible assets (liabilities)				4.5					(0.2)					0					0.7					0					1.5	0
Payments to Acquire Businesses, Gross				76.0					59.5															87.0					89.7	63.2
Business acquisition, total cash consideration				$ 76.0					$ 42.9					$ 26.0					$ 48.6					$ 87.0					$ 89.7	$ 63.2