Restructuring Reserve - Additional Information (Detail)	9 Months Ended	12 Months Ended
	Oct. 31, 2011	Jan. 31, 2011 Person	Jan. 31, 2010 Entity Person	Jan. 31, 2009 Person Entity
Restructuring Cost and Reserve [Line Items]
Restructuring plan	During fiscal 2011, fiscal 2010 and fiscal 2009 Autodesk initiated restructuring plans ("Fiscal 2011 Plan," "Fiscal 2010 Plan" and "Fiscal 2009 Plan," respectively) in order to further reduce operating costs.
Restructuring program, reduced the number of employees		200	430	700
Leased facilities that were consolidated			32	27