Business and Summary of Significant Accounting Policies Additional Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 400.0
Total sales to the distributors Tech Data Corporation and its global affiliates ("Tech Data") relative to Autodesk's consolidated net revenue	23.00%	17.00%	16.00%
Concentration Risk, Percentage		21.00%	22.00%
Depreciation, Nonproduction	45.6	43.7	47.6
Write-down of fully depreciated assets	83.9
Finite-Lived Intangible Assets, Amortization Expense	82.0	71.8	57.8
Goodwill, Impairment Loss	0	0	0
Advertising Expense	$ 15.6	$ 21.3	$ 18.8
Purchased Technologies, Customer Relationships and Trade Names
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life	4 years 10 months 24 days
Accounts Receivable
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Concentration Risk, Percentage	23.00%	21.00%