Financial Instruments - Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions		Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Derivatives, Fair Value [Line Items]
Notional amount of foreign currency forward contracts not designated as cash flow hedges		$ 142.4	$ 336.6
Net loss expected to be recognized into earnings		1,619.6	2,219.2	$ 2,261.5	$ 2,043.2
Derivative asset, net		8.3	21.3
Derivative liability, net		6.4	5.4
Net Unrealized Gains (Losses) on Derivative Instruments
Derivatives, Fair Value [Line Items]
Net loss expected to be recognized into earnings		15.7	42.8	$ 3.5
Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Notional amount of foreign currency forward contracts not designated as cash flow hedges		231.6	44.6
Designated as Hedging Instrument | Foreign Exchange Contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, net	[1]	3.4	20.4
Derivative asset, gross		5.1	23.8
Designated as Hedging Instrument | Foreign Exchange Contracts | Other Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, net	[2]	3.4	5.4
Derivative liability, gross		5.1	8.7
Not Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative asset, net		4.9	0.9
Not Designated as Hedging Instrument | Other Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, net	[2]	$ 3.0	$ 0.0

[1] Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $5.1 million and $23.8 million at January 31, 2016 and January 31, 2015, respectively.

[2] Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $5.1 million and $8.7 million at January 31, 2016 and January 31, 2015, respectively.