Stock-Based Compensation Expense - Additional Information (Detail) (USD $)	12 Months Ended
	Jan. 31, 2012		Jan. 31, 2011		Jan. 31, 2010
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share based compensation arrangement by share based payment award options expiration term	8
Share-Based Compensation Shares Granted to Share Issued	$ 2.11
Option expiration term (in years)	8
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	3.9
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$ 199,300,000
Total compensation costs related to non-vested options	74,900,000
Total compensation costs related to non-vested options, expected to be recognized over a weighted average period (in years)	1.7
Sale of Stock, Price Per Share	$ 36.00
Percentage of compensation that eligible employees can use to purchase common stock, maximum	15.00%
Percentage of fair market value eligible employees can purchase common stock, minimum	85.00%
Shares available for future issuance, increases on the first trading day of each fiscal year	10,000,000
Shares available for future issuance, percentage of outstanding shares plus any shares repurchased by Autodesk	2.00%
Weighted average grant date fair value	$ 14.04	[1]	$ 9.30	[1]	$ 6.13	[1]
Restricted Stock Units (RSUs)
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Restricted stock granted	1,594,500
Compensation expense	29,100,000		8,900,000
Total compensation cost related to non-vested awards not yet recognized	47,700,000
Total compensation cost related to non-vested awards not yet recognized, weighted average period of recognition (in years)	1.6
Number of restricted stock granted but unreleased	2,170,600
Restricted Stock Awards
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Restricted stock granted	16,000
Compensation expense	600,000		700,000
Total compensation cost related to non-vested awards not yet recognized	200,000
Total compensation cost related to non-vested awards not yet recognized, weighted average period of recognition (in years)	0.4
Number of restricted stock granted but unreleased	13,500
Employee Stock Plan 2012
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares of common stock reserved for issuance	21,200,000
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	15,200,000
Stock Issued During Period, Shares, Share-based Compensation, Forfeited	6,000,000
Share-Based Compensation Shares Granted to Share Issued	$ 1.79
Maximum vesting period of options and restricted stock granted	over a four year period
Shares available for future issuance	15,400,000
Employee Stock Plan 2012 | Minimum
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share based compensation arrangement by share based payment award options expiration term	4
Option expiration term (in years)	4
Employee Stock Plan 2012 | Maximum
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share based compensation arrangement by share based payment award options expiration term	10
Option expiration term (in years)	10
Outside directors stock plan 2012
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share based compensation arrangement by share based payment award options expiration term	7
Shares of common stock reserved for issuance	2,600,000
Maximum vesting period of options and restricted stock granted	over a four year period
Option expiration term (in years)	7
Shares available for future issuance	2,600,000
Minimum vesting period of options and restricted stock granted	one year
ESP Plan
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares available for future issuance	29,700,000
Shares issued under the ESP Plan	2,800,000		3,200,000		3,100,000
Shares issued under the ESP Plan, average price	$ 18.26		$ 14.77		$ 14.41
Weighted average grant date fair value	$ 9.95		$ 10.11		$ 7.19
Employee Service Share Based Compensation recognized Compensation Costs On Nonvested Restricted Shares	$ 23,800,000		$ 18,200,000		$ 26,600,000

[1] The weighted average grant date fair value per share of stock options granted is calculated, as of the stock option grant date, using the BSM option pricing model.