Employee and Director Stock Plans - Intrinsic Value of Options Exercised and Weighted Average Grant Date Fair Value of Stock Options Granted (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Jan. 31, 2014		Jan. 31, 2013		Jan. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Intrinsic value of options exercised	$ 149.0	[1]	$ 90.9	[1]	$ 85.7	[1]
Weighted average grant date fair value per share of stock options granted	$ 0.00	[2]	$ 13.39	[2]	$ 14.04	[2]

[1] The intrinsic value of options exercised is calculated as the difference between the exercise price of the option and the market value of the stock on the date of exercise.

[2] 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. For the twelve months ended January 31, 2014, Autodesk did not grant stock options.