Segments - Concerning the Operations Of Reportable Segments (Details) - USD ($) $ in Millions		3 Months Ended										12 Months Ended
		Jan. 31, 2016	[1]	Oct. 31, 2015	Jul. 31, 2015	[2]	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Segment Reporting Information [Line Items]
Net revenue		$ 648.3		$ 599.8	$ 609.5		$ 646.5	$ 664.6	$ 618.0	$ 637.1	$ 592.5	$ 2,504.1	$ 2,512.2	$ 2,273.9
Gross profit		$ 553.4		$ 508.8	$ 516.5		$ 554.7	$ 575.1	$ 532.0	$ 549.2	$ 513.8	2,133.4	2,170.1	1,999.6
Depreciation and Amortization												145.8	145.9	128.9
Architecture, Engineering, and Construction
Segment Reporting Information [Line Items]
Net revenue												949.1	872.6	730.6
Gross profit												857.0	785.8	663.8
Depreciation and Amortization												1.5	1.3	0.2
Platform Solutions and Emerging Business
Segment Reporting Information [Line Items]
Net revenue												670.4	796.7	789.2
Gross profit												572.0	712.3	716.8
Depreciation and Amortization												9.8	6.8	5.5
Manufacturing
Segment Reporting Information [Line Items]
Net revenue												724.6	675.6	579.4
Gross profit												638.1	604.0	531.5
Depreciation and Amortization												1.3	3.0	0.9
Media and Entertainment
Segment Reporting Information [Line Items]
Net revenue												160.0	167.3	174.7
Gross profit												127.1	127.3	137.8
Depreciation and Amortization												0.2	0.3	0.2
Unallocated
Segment Reporting Information [Line Items]
Gross profit	[3]											(60.8)	(59.3)	(50.3)
Depreciation and Amortization												$ 133.0	$ 134.5	$ 122.1

[1] Subsequent to furnishing preliminary financial statements on Form 8-K on February 25, 2016 for the three and twelve months ended January 31, 2016, Autodesk identified a $4.5 million tax adjustment associated with deemed foreign withholding taxes related to non-permanently reinvested earnings in foreign jurisdictions which have not yet repatriated resulting in changes to the Consolidated Financial Statements as reflected in this Annual Report on Form 10-K. This non-cash adjustment resulted in an increase to GAAP diluted loss per share from $(0.15) to $(0.17) for the three months ended January 31, 2016.

[2] Certain second quarter fiscal 2016 balances have been revised to include the correction of an error identified in the third quarter of fiscal 2016, resulting in an additional $33.1 million of income tax expense from the previously reported results, primarily related to the establishment of a valuation allowance. See Note 1, "Business and Summary of Significant Accounting Policies" for further discussion.

[3] (1)Unallocated amounts primarily relate to corporate expenses and other costs and expenses that are managed outside the reportable segments, including stock-based compensation expense.