Stock-based Compensation Expense Summary of Restricted Stock Award and Restricted Stock Unit Activity (Details)	3 Months Ended
	Apr. 30, 2017 $ / shares shares
Restricted Stock Units (RSUs) and Performance Shares
Unvested Restricted Stock Units
Unvested restricted stock units, beginning balance (shares)	7,622,400
Granted (shares)	622,500
Vested (shares)	(890,900)
Canceled/Forfeited (shares)	(105,400)
Unvested restricted stock units, ending balance (shares)	7,273,300
Weighted average grant date fair value per share
Unvested restricted stock units, beginning balance (usd per share) | $ / shares	$ 60.13
Granted (in usd per share) | $ / shares	90.47
Vested (in usd per share) | $ / shares	57.85
Canceled/Forfeited (in usd per share) | $ / shares	57.62
Unvested restricted stock units, ending balance (usd per share) | $ / shares	$ 63.73
Performance Stock Unit
Unvested Restricted Stock Units
Granted (shares)	200,000
Performance adjustment (shares)	24,700	[1]
Weighted average grant date fair value per share
Performance adjustment (in usd per share) | $ / shares	$ 61.79	[1]
Minimum | Restricted Stock Units (RSUs) and Performance Shares
Weighted average grant date fair value per share
Performance shares units payout	99.70%
Maximum | Restricted Stock Units (RSUs) and Performance Shares
Weighted average grant date fair value per share
Performance shares units payout	114.70%

[1] Based on Autodesk's financial results and relative total stockholder return for the fiscal 2017 performance period. The performance stock units were attained at rates ranging from 99.7% to 114.7% of the target award.