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Concentration of Credit Risk - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended
Jul. 31, 2011
Jul. 31, 2010
Jul. 31, 2011
Jul. 31, 2010
Jul. 31, 2011
Accounts Receivable
Jan. 31, 2011
Accounts Receivable
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]            
Line of credit facility, maximum borrowing capacity $ 400.0   $ 400.0      
Total sales to the distributors Tech Data Corporation and its global affiliates ("Tech Data") relative to Autodesk's consolidated net revenue 17.00% 15.00% 17.00% 16.00%    
Percentage of gross accounts receivable accounted for by Tech Data         18.00% 16.00%