Schedule Of Share-based Compensation Options Activity (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Jan. 31, 2013
Number of Shares
Options outstanding at January 31, 2013	19.0
Options exercisable at January 31, 2013	13.2
Weighted average price per share
Options outstanding at January 31, 2013	32.69
Options exercisable at January 31, 2013	31.80
Employee Stock Plan 2012
Weighted average price per share
Share Based Compensation Arrangement By Share Based Payment Award Maximum Vesting Period For Stock Options	3 years
Outside directors stock plan 2012
Weighted average price per share
Share Based Compensation Arrangement By Share Based Payment Award Maximum Vesting Period For Stock Options	1 year
Stock Options and Restricted Stock [Member] | Employee Stock Plan 2012
Number of Shares
Granted	7.0
Stock Options [Member]
Number of Shares
Options outstanding at January 31, 2012	28.4
Granted	0.1
Exercised	(6.6)
Cancelled	(2.9)
Options outstanding at January 31, 2013	19.0
Options exercisable at January 31, 2013	13.2
Options vested and exercisable as of January 31, 2013	18.8	[1]
Options available for grant at January 31, 2013	14.0
Weighted average price per share
Options outstanding at January 31, 2012	31.39
Granted	36.59
Exercised	24.67
Cancelled	38.38
Options outstanding at January 31, 2013	32.69
Options exercisable at January 31, 2013	31.80
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	32.63	[1]
Options Outstanding - Weighted average contractual life (in years)	3 years 9 months 18 days
Options Outstanding - Aggregate intrinsic value	153.4	[2],[3]
Options Exercisable - Weighted average contractual life (in years)	2 years 8 months 12 days
Options Exercisable - Aggregate intrinsic value	120.8	[2],[3]
Options, Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	3 years 8 months 12 days	[1]
Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	153.0	[1],[2]

[1] Options expected to vest reflect an estimated forfeiture rate.

[2] Represents the total pre-tax intrinsic value, based on Autodesk’s closing stock price of $38.88 per share as of January 31, 2013, which would have been received by the option holders had all option holders exercised their options as of that date.

[3] Represents the total intrinsic value, based on Autodesk’s closing stock price of $38.88 per share as of January 31, 2013, which would have been received by the option holders had all option holders exercised their options as of that date.