Stock-based Compensation Expense Schedule Of Share-based Compensation Options Activity (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Apr. 30, 2014		Jan. 31, 2014
Number of Shares
Options outstanding (in shares)	5.9
Granted (in shares)	0	[1]
Exercised (in shares)	(1.2)
Canceled/Forfeited (in shares)	0
Options outstanding (in shares)	4.7
Options vested and exercisable (in shares)	4.3
Options vested (in shares)	4.7	[2]
Options available (in shares)	19.9
Weighted average exercise price per share
Outstanding (in dollars per share)	$ 33.88		$ 33.54
Granted (in dollars per share)	$ 0.00	[1]
Exercised (in dollars per share)	$ 32.24
Canceled/Forfeited (in dollars per share)	$ 0.00
Vested and exercisable (in dollars per share)	$ 33.44
Vested (in dollars per share)	$ 33.88	[2]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options outstanding, Weighted average remaining contractual term	4 years 8 months 1 day
Options vested and exercisable, Weighted average remaining contractual term	4 years 6 months
Options vested, Weighted average remaining contractual term	4 years 8 months 1 day	[2]
Options outstanding, Aggregate Intrinsic Value	$ 66.7	[3]
Options vested and exercisable, Aggregate Intrinsic Value	62.9	[3]
Options vested, Aggregate Intrinsic Value	$ 66.7	[2],[3]
$2.28 - $29.49
Number of Shares
Options outstanding (in shares)	1.6
Options vested and exercisable (in shares)	1.5
Weighted average exercise price per share
Outstanding (in dollars per share)	$ 23.47
Vested and exercisable (in dollars per share)	$ 23.25
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise Price, Lower Limit (in dollars per share)	$ 2.28
Exercise Price, Upper Limit (in dollars per share)	$ 29.49
$29.50 - $38.55
Number of Shares
Options outstanding (in shares)	1.0
Options vested and exercisable (in shares)	0.9
Weighted average exercise price per share
Outstanding (in dollars per share)	$ 33.42
Vested and exercisable (in dollars per share)	$ 33.17
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise Price, Lower Limit (in dollars per share)	$ 29.50
Exercise Price, Upper Limit (in dollars per share)	$ 38.55
$41.62 - $43.81
Number of Shares
Options outstanding (in shares)	2.1
Options vested and exercisable (in shares)	1.9
Weighted average exercise price per share
Outstanding (in dollars per share)	$ 42.16
Vested and exercisable (in dollars per share)	$ 42.06
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercise Price, Lower Limit (in dollars per share)	$ 41.62
Exercise Price, Upper Limit (in dollars per share)	$ 43.81

[1] Autodesk did not grant stock options in the three months ended April 30, 2014.

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

[3] Represents the total pre-tax intrinsic value, based on Autodesk’s closing stock price of $48.02 per share as of April 30, 2014, which would have been received by the option holders had all option holders exercised their options as of that date.