Financial Instruments Fair Value of Derivative Instruments (Details) (USD $) In Millions, unless otherwise specified	Apr. 30, 2014		Jan. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 379.8		$ 351.7
Net gain on derivative instruments	0.2		3.5
Derivative assets	7.5		21.3
Derivative liabilities	0.5		1.7
Not designated as hedging instrument | Prepaid expenses and other current assets and Other assets
Derivatives, Fair Value [Line Items]
Derivative assets	4.8		16.9
Foreign currency contracts
Derivatives, Fair Value [Line Items]
Derivative, notional amount	25.1		205.5
Foreign currency contracts | Designated as hedging instrument | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative assets	2.7	[1]	4.4	[1]
Derivative assets, gross	4.3		5.9
Foreign currency contracts | Designated as hedging instrument | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	0.5	[2]	1.7	[2]
Derivative liabilities, gross	$ 2.1		$ 3.2

[1] Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $4.3 million and $5.9 million at April 30, 2014 and January 31, 2014, respectively.

[2] Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $2.1 million and $3.2 million at April 30, 2014 and January 31, 2014, respectively.