Autodesk (ADSK) 10-K 18 Mar 15 2015 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Jan. 31, 2015	Feb. 28, 2015	Jul. 31, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	AUTODESK INC.
Entity Central Index Key	769397
Current Fiscal Year End Date	-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Jan-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		227,204,316
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$12.10

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Net revenue:
License and other	$1,341.40	$1,254.90	$1,364.10
Subscription	1,170.80	1,019	948.1
Total net revenue	2,512.20	2,273.90	2,312.20
Cost of revenue:
Cost of license and other revenue	208.5	178.7	166
Cost of subscription revenue	133.6	95.6	72.5
Total cost of revenue	342.1	274.3	238.5
Gross profit	2,170.10	1,999.60	2,073.70
Operating expenses:
Marketing and sales	998	842.6	875.5
Research and development	725.2	611.1	600
General and administrative	283.3	211.8	206.3
Amortization of purchased intangibles	39.8	36.5	42.1
Restructuring charges, net	3.1	12.8	43.9
Total operating expenses	2,049.40	1,714.80	1,767.80
Income from operations	120.7	284.8	305.9
Interest and other (expense) income, net	-37.7	-4.9	4.1
Income before income taxes	83	279.9	310
Provision for income taxes	-1.2	-51.1	-62.6
Net income	$81.80	$228.80	$247.40
Basic net income per share (usd per share)	$0.36	$1.02	$1.09
Diluted net income per share (usd per share)	$0.35	$1	$1.07
Weighted average shares used in computing basic net income per share	227.1	224	226.4
Weighted average shares used in computing diluted net income per share	232.4	229.6	231.7

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$81.80	$228.80	$247.40
Other comprehensive (loss) income, net of reclassifications:
Net gain (loss) on derivative instruments (net of tax effect of ($0.7), $1.1, and ($0.5))	39.3	0.7	-6.4
Change in net unrealized gain (loss) on available-for-sale securities (net of tax effect of ($0.2), $0.3, and ($0.6))	-0.2	-1.1	2
Change in defined benefit pension items (net of tax effect of $1.8, $0.6, and $0.4)	-16	5.4	-6.1
Net change in cumulative foreign currency translation (loss) gain (net of tax effect of $4.9, $2.1, and $2.1)	-75.8	0.1	-1.1
Total other comprehensive (loss) income	-52.7	5.1	-11.6
Total comprehensive income	$29.10	$233.90	$235.80

CONSOLIDATED_STATEMENTS_OF_COM1

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parentheticals) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Statement of Comprehensive Income [Abstract]
Net gain (loss) on derivative instruments, tax	($0.70)	$1.10	($0.50)
Change in net unrealized (loss) gain on available-for-sale securities, tax	-0.2	0.3	-0.6
Change in unfunded portion of pension plans, tax	1.8	0.6	0.4
Net change in cumulative foreign currency translation gain (loss), tax	$4.90	$2.10	$2.10

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Millions, unless otherwise specified
Current assets:
Cash and cash equivalents	$1,410.60	$1,853
Marketable securities	615.8	414.1
Accounts receivable, net	458.9	423.7
Deferred income taxes, net	85.1	56.8
Prepaid expenses and other current assets	100.9	87.4
Total current assets	2,671.30	2,835
Marketable securities	273	277.3
Computer equipment, software, furniture, and leasehold improvements, net	159.2	130.3
Developed technologies, net	86.5	63.1
Goodwill	1,456.20	1,009.90
Deferred income taxes, net	100	131.1
Other assets	167.6	148.3
Total assets	4,913.80	4,595
Current liabilities:
Accounts payable	100.5	84.5
Accrued compensation	253.3	181.2
Accrued income taxes	28.2	24.3
Deferred revenue	900.8	696.2
Other accrued liabilities	117.3	85.3
Total current liabilities	1,400.10	1,071.50
Deferred revenue	256.3	204.4
Long term income taxes payable	158.8	211.8
Long term notes payable, net of discount	747.2	746.4
Other liabilities	132.2	99.4
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value; shares authorized 2.0; none issued or outstanding at January 31, 2015 and 2014	0	0
Common stock and additional paid-in capital, $0.01 par value; shares authorized 750.0; 227.0 outstanding at January 31, 2015 and 226.7 outstanding at January 31, 2014	1,773.10	1,637.30
Accumulated other comprehensive loss	-53.3	-0.6
Retained earnings	499.4	624.8
Total stockholders’ equity	2,219.20	2,261.50
Total liabilities and stockholders' equity	$4,913.80	$4,595

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) (USD $)	Jan. 31, 2015	Jan. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares outstanding	227,000,000	226,700,000

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Operating Activities
Net income	$81.80	$228.80	$247.40
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion	145.9	128.9	127.8
Stock-based compensation expense	165.6	132.2	156.3
Excess tax benefits from stock-based compensation	-0.5	-9.1	-12.9
Restructuring charges, net	3.1	12.8	43.9
Other operating activities	16.2	-16.1	6.7
Changes in operating assets and liabilities, net of business combinations:
Accounts receivable	-17.3	72.3	-98.1
Deferred income taxes	-18.8	-49.4	-28.3
Prepaid expenses and other current assets	6.8	-20.3	0.1
Accounts payable and accrued liabilities	130.8	-19.6	-28.3
Deferred revenue	245.2	66	113.3
Accrued income taxes	-50.7	37	31.2
Net cash provided by operating activities	708.1	563.5	559.1
Investing Activities
Purchases of marketable securities	-1,355.10	-1,214.20	-1,397.70
Sales of marketable securities	190	537	332.9
Maturities of marketable securities	969	742.1	764.8
Acquisitions, net of cash acquired	-630	-176.1	-263.7
Capital expenditures	-75.5	-64.2	-56.4
Other investing activities	-4	-18.6	-27.1
Net cash used in investing activities	-905.6	-194	-647.2
Financing Activities
Proceeds from issuance of common stock, net of issuance costs	135.4	288.2	220.2
Repurchase and retirement of common shares	-372.4	-423.8	-431.2
Draws on line of credit	0	0	110
Proceeds from debt, net of discount	0	0	745.6
Repayments of line of credit	0	0	-110
Excess tax benefits from stock-based compensation	0.5	9.1	12.9
Other financing activities	-3.4	0	-6.1
Net cash (used in) provided by financing activities	-239.9	-126.5	541.4
Effect of exchange rate changes on cash and cash equivalents	-5	-2.2	2
Net (decrease) increase in cash and cash equivalents	-442.4	240.8	455.3
Cash and cash equivalents at beginning of fiscal year	1,853	1,612.20	1,156.90
Cash and cash equivalents at end of fiscal year	1,410.60	1,853	1,612.20
Supplemental cash flow information:
Cash paid during the year for interest	20.4	20.5	0.4
Net cash paid during the year for income taxes	$63.40	$75.70	$59.70

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Total	Common stock and additional paid-in capital	Accumulated other comprehensive (loss) income	Retained earnings
In Millions, unless otherwise specified
Balance at Jan. 31, 2012	$1,882.90	$1,365.40	$5.90	$511.60
Balance (in shares) at Jan. 31, 2012		225.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common shares issued under stock plans (in shares)		10.2
Common shares issued under stock plans	220.2	220.2
Stock-based compensation expense	139.8	139.8
Tax benefits from employee stock plans	-4.3	-4.3
Net income	247.4			247.4
Other comprehensive loss income (loss)	-11.6		-11.6
Repurchase and retirement of common shares (in shares)		-12.5
Repurchase and retirement of common shares	-431.2	-271.3		-159.9
Balances at Jan. 31, 2013	2,043.20	1,449.80	-5.7	599.1
Balance (in shares) at Jan. 31, 2013		223.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common shares issued under stock plans (in shares)		13.6
Common shares issued under stock plans	288.2	288.2
Stock-based compensation expense	132.2	132.2
Tax benefits from employee stock plans	-12.2	-12.2
Net income	228.8			228.8
Other comprehensive loss income (loss)	5.1		5.1
Repurchase and retirement of common shares (in shares)		-10.5
Repurchase and retirement of common shares	-423.8	-220.7		-203.1
Balances at Jan. 31, 2014	2,261.50	1,637.30	-0.6	624.8
Balance (in shares) at Jan. 31, 2014	226.7	226.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common shares issued under stock plans (in shares)		7.2
Common shares issued under stock plans	135.4	135.4
Stock-based compensation expense	165.6	165.6
Net income	81.8			81.8
Other comprehensive loss income (loss)	-52.7		-52.7
Repurchase and retirement of common shares (in shares)		-6.9
Repurchase and retirement of common shares	-372.4	-165.2		-207.2
Balances at Jan. 31, 2015	$2,219.20	$1,773.10	($53.30)	$499.40
Balance (in shares) at Jan. 31, 2015	227	227

Business_and_Summary_of_Signif

Business and Summary of Significant Accounting Policies	12 Months Ended
	Jan. 31, 2015
Accounting Policies [Abstract]
Business and Summary Of Significant Accounting Policies	Business and Summary of Significant Accounting Policies
	Business
	Autodesk, Inc. (“Autodesk” or the “Company”) is a world leading design software and services company, offering customers productive business solutions through powerful technology products and services. The Company serves customers in the architecture, engineering, and construction; manufacturing; and digital media, consumer, and entertainment industries. The Company’s sophisticated software products enable its customers to experience their ideas before they are real by allowing them to imagine, design, and create their ideas and to visualize, simulate, and analyze real-world performance early in the design process by creating digital prototypes. These capabilities allow Autodesk’s customers to foster innovation, optimize and improve their designs, help save time and money, improve quality, and collaborate with others. Autodesk software products are sold globally, both directly to customers and through a network of resellers and distributors.
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of Autodesk and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.
	Reclassifications
	During the first quarter of fiscal 2014, Autodesk combined maintenance revenue and cloud services offering-related revenue into one category named “Subscription.” As a result, revenue and cost of revenue related to cloud service offerings previously reflected in “License and other revenue” and “Cost of license and other revenue” were reclassified to “Subscription revenue” and “Cost of subscription revenue.” These revenues and expenses have been reclassified in the Consolidated Statements of Operations for fiscal year 2013 to conform to the current period presentation as follows:
			Fiscal year ended January 31,
			2013
	Reclassifications within revenue:
	Decrease to License and other revenue		$	(26.5	)
	Increase to Subscription revenue		26.5
	Reclassifications within cost of revenue:
	Decrease to Cost of license and other revenue		$	(32.1	)
	Increase to Cost of subscription revenue		32.1
	During the second quarter of fiscal 2015, Autodesk elected to present amortization of purchased customer relationships, trade names, patents, and user lists as a separate line item within operating expenses. As a result, amortization previously reflected in “General and Administrative” expense was reclassified to “Amortization of Purchased Intangibles" within Operating Expenses. These expenses have been reclassified in the Consolidated Statements of Operations for fiscal years 2014 and 2013 to conform to the current period presentation as follows:
		Fiscal year ended January 31,
		2014				2013
	Reclassifications within operating expenses:
	(Decrease) to general and administrative	$	(36.5	)		$	(42.1	)
	Increase to amortization of purchased intangibles	36.5				42.1
	Use of Estimates
	The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in Autodesk’s consolidated financial statements and notes thereto. These estimates are based on information available as of the date of the consolidated financial statements. On a regular basis, management evaluates these estimates and assumptions. Actual results may differ materially from these estimates.
	Examples of significant estimates and assumptions made by management involve the determination of the fair value of acquired assets and liabilities, goodwill, financial instruments, long-lived assets and other intangible assets, the realizability of deferred tax assets, and the fair value of stock awards. The Company also makes assumptions, judgments, and estimates in determining the accruals for uncertain tax positions, variable compensation, partner incentive programs, product returns reserves, allowances for doubtful accounts, asset retirement obligations, and legal contingencies.
	Foreign Currency Translation and Transactions
	The assets and liabilities of Autodesk’s foreign subsidiaries are translated from their respective functional currencies into U.S. dollars at the rates in effect at the balance sheet date, and revenue and expense amounts are translated at exchange rates that approximate those rates in effect during the period in which the underlying transactions occur. Foreign currency translation adjustments are recorded as other comprehensive income (loss).
	Gains and losses realized from foreign currency transactions, those transactions denominated in currencies other than the foreign subsidiary’s functional currency, are included in interest and other income, net. Monetary assets and liabilities are remeasured using foreign currency exchange rates at the end of the period, and non-monetary assets are remeasured based on historical exchange rates.
	Derivative Financial Instruments
	Under its risk management strategy, Autodesk uses derivative instruments to manage its short-term exposures to fluctuations in foreign currency exchange rates which exist as part of ongoing business operations. Autodesk’s general practice is to hedge a majority of transaction exposures denominated in euros, Japanese yen, Swiss francs, British pounds, Canadian dollars, and Australian dollars. These instruments have maturities between one to 12 months in the future. Autodesk does not enter into any derivative instruments for trading or speculative purposes.
	The bank counterparties in all contracts expose Autodesk to credit-related losses in the event of their nonperformance. However, to mitigate that risk, Autodesk only contracts with counterparties who meet the Company’s minimum requirements under its counterparty risk assessment process. Autodesk monitors ratings, credit spreads, and potential downgrades on at least a quarterly basis. Based on Autodesk’s on-going assessment of counterparty risk, the Company will adjust its exposure to various counterparties. Autodesk generally enters into master netting arrangements, which reduce credit risk by permitting net settlement of transactions with the same counterparty. However, Autodesk does not have any master netting arrangements in place with collateral features.
	Autodesk accounts for its derivative instruments as either assets or liabilities on the balance sheet and carries them at fair value. Gains and losses resulting from changes in fair value are accounted for depending on the use of the derivative and whether it is designated and qualifies for hedge accounting. Derivatives that do not qualify for hedge accounting are adjusted to fair value through earnings. See Note 2, "Financial Instruments" for information regarding Autodesk's hedging activities.
	Cash and Cash Equivalents
	Autodesk considers all highly liquid investments with insignificant interest rate risk and remaining maturities of three months or less at the date of purchase to be cash equivalents. Cash equivalents are recorded at cost, which approximates fair value.
	Marketable Securities
	Marketable securities are stated at fair value. Marketable securities maturing within one year that are not restricted are classified as current assets.
	Autodesk determines the appropriate classification of its marketable securities at the time of purchase and re-evaluates such classification as of each balance sheet date. Autodesk carries all “available-for-sale securities” at fair value, with unrealized gains and losses, net of tax, reported in stockholders’ equity until disposition or maturity. Autodesk carries all “trading securities” at fair value, with unrealized gains and losses, recorded in “Interest and other income, net” in the Company’s Consolidated Statements of Operations.
	All of Autodesk’s marketable securities are subject to a periodic impairment review. The Company recognizes an impairment charge when a decline in the fair value of its investments below the cost basis is judged to be other-than-temporary. Autodesk considers various factors in determining whether to recognize an impairment charge, including the length of time and extent to which the fair value has been less than Autodesk’s cost basis, the financial condition and near-term prospects of the investee, and Autodesk’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in the market value. Autodesk did not record any other-than temporary impairment charges during fiscal years ended January 31, 2015, 2014, and 2013. For additional information, see “Concentration of Credit Risk” within this Note 1 and Note 2, “Financial Instruments.”
	Accounts Receivable, Net
	Accounts receivable, net, consisted of the following as of January 31:
		2015				2014
	Trade accounts receivable	$	495.4			$	464.6
	Less: Allowance for doubtful accounts	(6.3		)		(4.9		)
	Product returns reserve	(2.6		)		(4.0		)
	Partner programs and other obligations	(27.6		)		(32.0		)
	Accounts receivable, net	$	458.9			$	423.7
	Allowances for uncollectible trade receivables are based upon historical loss patterns, the number of days that billings are past due, and an evaluation of the potential risk of loss associated with problem accounts.
	The product returns reserves are based on historical experience of actual product returns, estimated channel inventory levels, the timing of new product introductions, channel sell-in for applicable markets, and other factors.
	As part of the indirect channel model, Autodesk has a partner incentive program that uses quarterly attainment of monetary rewards to motivate distributors and resellers to achieve mutually agreed upon business goals in a specified time period. A portion of these incentives reduce license and other revenue in the current period. The remainder, which relates to incentives on our Subscription Program, is recorded as a reduction to deferred revenue in the period the maintenance transaction is billed and subsequently recognized as a reduction to maintenance revenue over the contract period. These incentive balances do not require significant assumptions or judgments. The reserves associated with the partner incentive program are treated on the consolidated balance sheet as either contra account receivable (when due to distributors and direct resellers) or accounts payable (when due to indirect resellers).
	Concentration of Credit Risk
	Autodesk places its cash, cash equivalents, and marketable securities in highly liquid instruments with, and in the custody of, diversified financial institutions globally with high credit ratings and limits the amounts invested with any one institution, type of security, and issuer.
	Geographical concentrations of consolidated cash, cash equivalents, and marketable securities held by Autodesk as of January 31:
		2015			2014
	United States	19	%		25	%
	Other Americas	1	%		1	%
	Europe, Middle East, and Africa (“EMEA”)	56	%		57	%
	Asia Pacific (“APAC”)	24	%		17	%
	Autodesk’s primary commercial banking relationship is with Citigroup Inc. and its global affiliates. Citibank, N.A., an affiliate of Citigroup, is one of the lead lenders and an agent in the syndicate of Autodesk’s $400.0 million line of credit facility. It is Autodesk’s policy to limit the amounts invested with any one institution by type of security and issuer.
	Autodesk’s accounts receivable are derived from sales to a large number of resellers, distributors, and direct customers in the Americas; EMEA; and APAC geographies. Autodesk performs ongoing evaluations of these partners' financial condition and limits the amount of credit extended when deemed necessary, but generally does not require collateral from such parties. Total sales to the Company's largest distributor Tech Data Corporation, and its global affiliates (“Tech Data”), accounted for 25%, 24%, and 23% of Autodesk's net revenue for fiscal years ended January 31, 2015, 2014, and 2013, respectively. The majority of the net revenue from sales to Tech Data relates to Autodesk's Platform Solutions and Emerging Business ("PSEB") segment and is for sales made outside of the United States. In addition, Tech Data accounted for 22% and 24% of trade accounts receivable at January 31, 2015 and 2014, respectively.
	Computer Equipment, Software, Furniture, and Leasehold Improvements, Net
	Computer equipment, software, and furniture are depreciated using the straight-line method over the estimated useful lives of the assets, which range from three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the lease term. Depreciation expense was $52.1 million in fiscal 2015, $47.2 million in fiscal 2014, and $45.6 million in fiscal 2013.
	Computer equipment, software, furniture, leasehold improvements and the related accumulated depreciation at January 31 were as follows:
		2015				2014
	Computer hardware, at cost	$	194			$	163
	Computer software, at cost	84.9				80.9
Leasehold improvements, land, and buildings, at cost	176.3				163.7
Furniture and equipment, at cost	53				51.7
Computer software, hardware, leasehold improvements, furniture, and equipment, at cost	508.2				459.3
Less: Accumulated depreciation	(349.0		)		(329.0		)
Computer software, hardware, leasehold improvements, furniture, and equipment, net	$	159.2			$	130.3
Costs incurred for computer software developed or obtained for internal use are capitalized for application development activities, if material, and immediately expensed for preliminary project activities and post-implementation activities. These capitalized costs are amortized over the software’s expected useful life, which is generally three years. During fiscal 2015, Autodesk wrote-off $25.8 million of fully depreciated assets.
Software Development Costs
Software development costs incurred prior to the establishment of technological feasibility are included in research and development expenses. Autodesk defines establishment of technological feasibility as the completion of a working model. Software development costs incurred subsequent to the establishment of technological feasibility through the period of general market availability of the products are capitalized and generally amortized over a three year period, if material. Autodesk had no material capitalized software development costs at January 31, 2015 and January 31, 2014.
Other Intangible Assets, Net
Other intangible assets include developed technologies, customer relationships, trade names, patents, user lists, and the related accumulated amortization. These assets are shown as “Developed technologies, net” and as part of “Other assets” in the Consolidated Balance Sheet. The majority of Autodesk’s other intangible assets are amortized to expense over the estimated economic life of the product, which ranges from one to ten years. Amortization expense for developed technologies, customer relationships, trade names, patents, and user lists was $92.9 million in fiscal 2015, $80.7 million in fiscal 2014 and $82.0 million in fiscal 2013.
Other intangible assets and related accumulated amortization at January 31 were as follows:
	2015				2014
Developed technologies, at cost	$	538.4			$	462.4
Customer relationships, trade names, patents, and user lists, at cost (1)	348.9				268.1
	887.3				730.5
Less: Accumulated amortization	(715.4		)		(626.2		)
Other intangible assets, net	$	171.9			$	104.3
_______________
-1	Included as a net balance in “Other assets” in the Consolidated Balance Sheet. Customer relationships and trade names include the effects of foreign currency translation.
The weighted average amortization period for developed technologies, customer relationships, and trade names during fiscal 2015 was 4.2 years. Expected future amortization expense for developed technologies, customer relationships, trade names, patents, and user lists for each of the fiscal years ended thereafter is as follows:
	Fiscal Year ended January 31,
2016	$	73.2
2017	49.7
2018	24
2019	15.5
2020	5.3
Thereafter	4.2
Total	$	171.9
Goodwill
Goodwill consists of the excess of the consideration transferred over the fair value of net assets acquired in business combinations. Autodesk assigns goodwill to the reporting unit associated with each business combination, and tests goodwill for impairment annually in its fourth fiscal quarter or more often if circumstances indicate a potential impairment. For purposes of the goodwill impairment test, a reporting unit is an operating segment or one level below.
Autodesk has the option to perform an assessment of qualitative factors of impairment (“optional assessment”) prior to necessitating a two-step quantitative impairment test. Should the optional assessment be utilized for any given fiscal year, qualitative factors to consider include cost factors; financial performance; legal, regulatory, contractual, political, business, or other factors; entity specific factors; industry and market considerations, macroeconomic conditions, and other relevant events and factors affecting the reporting unit. If, after assessing the totality of events or circumstances, it is more likely than not that the fair value of the reporting unit is greater than its carrying value, then performing the two-step impairment test is unnecessary.
Therefore, the two-step quantitative impairment test is necessary when either Autodesk does not utilize the optional assessment or, as a result of the optional assessment, it is not more likely than not that the fair value of the reporting unit is greater than its carrying value. In performing the two-step impairment test, Autodesk uses discounted cash flow models which include assumptions regarding projected cash flows. Variances in these assumptions could have a significant impact on Autodesk's conclusion as to whether goodwill is impaired, or the amount of any impairment charge. Impairment charges, if any, result from instances where the fair values of net assets associated with goodwill are less than their carrying values. As changes in business conditions and assumptions occur, Autodesk may be required to record impairment charges. The process of evaluating the potential impairment of goodwill is subjective and requires significant judgment at many points during the analysis. The value of Autodesk’s goodwill could also be impacted by future adverse changes such as: (i) declines in Autodesk’s actual financial results, (ii) a sustained decline in Autodesk’s market capitalization, (iii) significant slowdown in the worldwide economy or the industries Autodesk serves, or (iv) changes in Autodesk’s business strategy or internal financial forecast results.
For the fiscal 2015 annual goodwill impairment testing, Autodesk had five reporting units: PSEB, Manufacturing ("MFG"), Architecture, Engineering, and Construction ("AEC"), Media and Entertainment ("M&E"), and Delcam.
For the annual impairment assessment in fiscal 2015, Autodesk utilized the optional assessment for Delcam. Based on a review of the qualitative factors described above, we determined that for our Delcam reporting unit, it was more likely than not that the fair value of the reporting unit exceeded the carrying value. As a result, we concluded that performing the two-step impairment test was not necessary for Delcam.
For each of the remaining four reporting units, Autodesk did not utilize the optional assessment but rather performed the quantitative two-step impairment test. In performing the quantitative two-step test, Autodesk used a discounted cash flow model which included assumptions regarding projected cash flows. Based on this testing, Autodesk determined that the fair value was substantially in excess of the carrying value for each of the four reporting units and therefore the goodwill of each reporting unit was not impaired during the fiscal year ended January 31, 2015. In addition, Autodesk did not recognize any goodwill impairment losses in fiscal 2014 or 2013.
The change in the carrying amount of goodwill during the fiscal year ended January 31, 2015 is as follows:
	Platform Solutions and Emerging Business				Architecture, Engineering, and Construction				Manufacturing				Media and Entertainment			Delcam			Total
Balance as of January 31, 2014
Goodwill	$	142.3			$	415.2			$	411.6			$	190		$	—		$	1,159.10
Accumulated impairment losses	—				—				—				(149.2		)	—			(149.2		)
	142.3				415.2				411.6				40.8			—			1,009.90
Delcam plc	—				—				—				—			196.1			196.1
Within Technologies Limited	80.6				—				—				—						80.6
Shotgun Software Inc.	—				—				—				43.2						43.2
Goodwill acquired from other acquisitions	117.8				28.1				20.1				15.3						181.3
Effect of foreign currency translation, purchase accounting adjustments, and other	(13.2		)		(16.3		)		(9.0		)		(3.3		)	(13.1		)	(54.9		)
Balance as of January 31, 2015
Goodwill	327.5				427				422.7				245.2			183			1,605.40
Accumulated impairment losses	—				—				—				(149.2		)	—			(149.2		)
	$	327.5			$	427			$	422.7			$	96		$	183		$	1,456.20
The change in the carrying amount of goodwill during the fiscal year ended January 31, 2014 is as follows:
	Platform Solutions and Emerging Business				Architecture, Engineering, and Construction				Manufacturing				Media and Entertainment			Total
Balance as of January 31, 2013
Goodwill	$	129.5			$	310.3			$	389.9			$	191		$	1,020.70
Accumulated impairment losses	—				—				—				(149.2		)	(149.2		)
	129.5				310.3				389.9				41.8			871.5
Graitec SA	—				73.4				—				—			73.4
Goodwill acquired from other acquisitions	12.8				32				22.2				—			67
Effect of foreign currency translation, purchase accounting adjustments, and other	—				(0.5		)		(0.5		)		(1.0		)	(2.0		)
Balance as of January 31, 2014
Goodwill	142.3				415.2				411.6				190			1,159.10
Accumulated impairment losses	—				—				—				(149.2		)	(149.2		)
	$	142.3			$	415.2			$	411.6			$	40.8		$	1,009.90
Purchase accounting adjustments reflect revisions made to the Company’s preliminary purchase price allocations during fiscal 2015 and 2014.
Impairment of Long-Lived Assets
At least annually or more frequently as circumstances dictate, Autodesk reviews its long-lived assets for impairment whenever impairment indicators exist.  Autodesk continually monitors events and changes in circumstances that could indicate the carrying amounts of its long-lived assets may not be recoverable. When such events or changes in circumstances occur, Autodesk assesses recoverability of these assets.  Recoverability is measured by comparison of the carrying amounts of the assets to the future undiscounted cash flows the assets are expected to generate.  If the long-lived assets are considered to be impaired, the impairment to be recognized is equal to the amount by which the carrying value of the assets exceeds its fair market value. Autodesk did not recognize any impairment of long-lived assets during the fiscal years ended January 31, 2015, 2014, and 2013, respectively.
In addition to the recoverability assessments, Autodesk routinely reviews the remaining estimated useful lives of its long-lived assets. Any reduction in the useful life assumption will result in increased depreciation and amortization expense in the quarter when such determinations are made, as well as in subsequent quarters.
Deferred Tax Assets
Deferred tax assets arise primarily from tax credits, net operating losses, and timing differences for reserves, accrued liabilities, stock options, deferred revenue, purchased technologies, and capitalized intangibles, partially offset by the establishment of U.S. deferred tax liabilities on unremitted earnings from certain foreign subsidiaries, and valuation allowances against U.S. and foreign deferred tax assets. We perform a quarterly assessment of the recoverability of these net deferred tax assets and believe that we will generate sufficient future taxable income in appropriate tax jurisdictions to realize the net deferred tax assets. They are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. Valuation allowances are established when necessary to reduce gross deferred tax assets to the amount “more likely than not” expected to be realized.
Revenue Recognition
Autodesk recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable, and collection is probable.
For multiple element arrangements containing only software and software-related elements, Autodesk allocates the sales price among each of the deliverables using the residual method, under which revenue is allocated to undelivered elements based on their vendor-specific objective evidence (“VSOE”) of fair value. VSOE is the price charged when an element is sold separately or a price set by management with the relevant authority. If Autodesk does not have VSOE of an undelivered element, revenue recognition is deferred on the entire sales arrangement until all elements for which Autodesk does not have VSOE are delivered. If Autodesk does not have VSOE for undelivered maintenance or services, the revenue for the arrangement is recognized over the longest contractual service period in the arrangement. Revenue recognition for significant lines of business is discussed further below.
For multiple element arrangements involving non-software elements, including cloud subscription services, our revenue recognition policy is based upon the accounting guidance contained in ASC 605, Revenue Recognition. For these arrangements, Autodesk first allocates the total arrangement consideration based on the relative selling prices of the software group of elements as a whole and the non-software elements. Autodesk then further allocates consideration within the software group to the respective elements within that group using the residual method as described above. Autodesk exercises judgment and uses estimates in connection with the determination of the amount of revenue to be recognized in each accounting period.
Autodesk allocates the total arrangement consideration among the various elements based on a selling price hierarchy. The selling price for a deliverable is based on its VSOE if available, third-party evidence ("TPE") if VSOE is not available, or the best estimated selling price ("BESP") if neither VSOE nor TPE is available. BESP represents the price at which Autodesk would transact for the deliverable if it were sold regularly on a standalone basis. To establish BESP for those elements for which neither VSOE nor TPE are available, Autodesk performs a quantitative analysis of pricing data points for historical standalone transactions involving such elements for a twelve-month period. As part of this analysis, Autodesk monitors and evaluates the BESP against actual pricing to ensure that it continues to represent a reasonable estimate of the standalone selling price, considering several other external and internal factors including, but not limited to, pricing and discounting practices, contractually stated prices, the geographies in which Autodesk offers products and services, and the type of customer (i.e. distributor, value-added reseller, and direct end user, among others). Autodesk analyzes BESP at least annually or on a more frequent basis if a significant change in our business necessitates a more timely analysis, or if significant selling price variances are experienced.
Autodesk’s assessment of likelihood of collection is also a critical element in determining the timing of revenue recognition. If collection is not probable, the revenue will be deferred until the earlier of when collection is deemed probable or cash is received.
License and other revenue are comprised of two components: (1) all forms of product license revenue and (2) other revenue.
(1) All Forms of Product License Revenue
Product license revenue includes: software license revenue from the sale of new seat licenses and upgrades and product revenue for Creative Finishing.
(2) Other Revenue
Other revenue includes revenue from consulting, training, Autodesk Developers Network, and Creative Finishing customer support, and is recognized over time, as the services are performed.
Autodesk's Subscription revenue consists of two components: maintenance revenue for our software products and revenue for our cloud service offerings, including Autodesk 360. Autodesk's maintenance program provides our commercial and educational customers of perpetual products with a cost effective and predictable budgetary option to obtain the productivity benefits of our new releases and enhancements when and if released during the term of their contracts. Under Autodesk's maintenance program, customers are eligible to receive unspecified upgrades when and if available, downloadable training courses, and online support. Autodesk recognizes maintenance revenue ratably over the term of the maintenance agreement, which is generally between one and three years but can occasionally be as long as five years. Revenue for Autodesk's cloud service offerings is recognized ratably over the contract term commencing with the date Autodesk's service is made available to customers and all other revenue recognition criteria have been satisfied.
Taxes Collected from Customers
Autodesk nets taxes collected from customers against those remitted to government authorities in the consolidated financial statements. Accordingly, taxes collected from customers are not reported as revenue.
Shipping and Handling Costs
Shipping and handling costs are included in cost of revenue for all periods presented.
Stock-based Compensation Expense
The following table summarizes stock-based compensation expense for fiscal 2015, 2014, and 2013, respectively, as follows:
	Fiscal Year Ended January 31,
	2015				2014				2013
Cost of license and other revenue	$	4.6			$	3.8			$	3.7
Cost of subscription	4.3				2.2				1.5
Marketing and sales	72.4				58.6				64.3
Research and development	56				43.7				61.8
General and administrative	28.3				23.9				25
Stock-based compensation expense related to stock awards and ESP Plan purchases	165.6				132.2				156.3
Tax benefit	(45.2		)		(36.4		)		(35.5		)
Stock-based compensation expense related to stock awards and ESP Plan purchases, net	$	120.4			$	95.8			$	120.8
Autodesk determines the grant-date fair value of its share-based payment awards using a Black-Scholes Merton Option ("BSM") pricing model or the quoted stock price on the date of grant, unless the awards are subject to market conditions, in which case Autodesk uses a binomial-lattice model (e.g., Monte Carlo simulation model). The Monte Carlo simulation model utilizes multiple input variables to estimate the probability that market conditions will be achieved. Autodesk uses the following assumptions to estimate the fair value of stock-based awards:
		Fiscal Year Ended				Fiscal Year Ended				Fiscal Year Ended
		January 31, 2015				January 31, 2014				January 31, 2013
		Performance Stock Unit (1)		ESP Plan		Performance Stock Unit (1)		ESP Plan		Stock Option (2)		ESP Plan
Range of expected volatilities		30%		29 - 33%		34%		27 - 36%		41 - 45%		41 - 44%
Range of expected lives (in years)		N/A		0.5 - 2.0		N/A		0.5 - 2.0		3.6 - 4.6		0.5 - 2.0
Expected dividends		—%		—%		—%		—%		—%		—%
Range of risk-free interest rates		0.10%		0.0 - 0.6%		0.10%		0.1 - 0.4%		0.5 - 0.8%		0.1 - 0.3%
_______________
-1	Autodesk did not grant PSUs in fiscal 2013 that were subject to market conditions.
-2	Autodesk did not grant stock options in fiscal 2015 or 2014.
Autodesk estimates expected volatility for stock-based awards based on the average of the following two measures. The first is a measure of historical volatility in the trading market for the Company’s common stock, and the second is the implied volatility of traded forward call options to purchase shares of the Company’s common stock. The expected volatility for PSUs subject to market conditions includes the expected volatility of Autodesk's peer companies within the S&P Computer Software Select Index.
Autodesk estimates the expected life of stock-based awards using both exercise behavior and post-vesting termination behavior as well as consideration of outstanding options.
Autodesk did not pay cash dividends in fiscal 2015, 2014, or 2013 and does not anticipate paying any cash dividends in the foreseeable future. Consequently, an expected dividend yield of zero is used in the Black-Scholes-Merton option pricing model and the Monte Carlo simulation model.
The risk-free interest rate used in the BSM option pricing model and the Monte Carlo simulation model for stock-based awards is the historical yield on U.S. Treasury securities with equivalent remaining lives.
Autodesk recognizes expense only for the stock-based awards that are ultimately expected to vest. Therefore, Autodesk has developed an estimate of the number of awards expected to cancel prior to vesting (“forfeiture rate”). The forfeiture rate is estimated based on historical pre-vest cancellation experience and is applied to all stock-based awards. The Company estimates forfeitures at the time of grant and revises those estimates in subsequent periods if actual forfeitures differ from those estimates.
Advertising Expenses
Advertising costs are expensed as incurred. Total advertising expenses incurred were $23.9 million in fiscal 2015, $15.6 million in fiscal 2014, and $15.6 million in fiscal 2013.
Net Income Per Share
Basic net income per share is computed based on the weighted average number of shares of common stock outstanding for the period, excluding stock options and restricted stock units. Diluted net income per share is computed based upon the weighted average shares of common shares outstanding for the period and potentially dilutive common shares, including the effect of stock options and restricted stock units under the treasury stock method.
Defined Benefit Pension Plans
The funded status of Autodesk's defined benefit pension plans is recognized in the Consolidated Balance Sheets. The funded status is measured as the difference between the fair value of plan assets and the projected benefit obligation for the fiscal years presented. The projected benefit obligation represents the actuarial present value of benefits expected to be paid upon retirement based on employee services already rendered and estimated future compensation levels. The fair value of plan assets represents the current market value of Autodesk's cumulative company and participant contributions made to the various plans in effect.
Net periodic benefit cost is recorded in the Consolidated Statements of Operations and includes service cost, interest cost, expected return on plan assets, amortization of prior service costs, and gains or losses previously recognized as a component of other comprehensive income. Certain events, such as changes in the employee base, plan amendments, and changes in actuarial assumptions may result in a change in the defined benefit obligation and the corresponding change to other comprehensive income.
Gains and losses and prior service costs not recognized as a component of net periodic benefit cost in the Consolidated Statements of Operations as they arise are recognized as a component of other comprehensive income in the Consolidated Statements of Comprehensive Income. Those gains and losses and prior service costs are subsequently amortized as a component of net periodic benefit cost over the average remaining service lives of the plan participants using a corridor approach to determine the portion of gain or loss subject to amortization.
The measurement of projected benefit obligations and net periodic benefit cost is based on estimates and assumptions that reflect the terms of the plans and use participant-specific information such as compensation, age and years of services, as well as certain assumptions, including estimates of discount rates, expected return of plan assets, rate of compensation increases, interest rates, and mortality rates.
Accounting Standards in Fiscal 2015
With the exception of those discussed below, there have been no recent changes in accounting pronouncements issued by the FASB or adopted by the Company during the fiscal year ended January 31, 2015, that are of significance, or potential significance, to the Company.
Accounting Standards Adopted
Effective February 1, 2014, Autodesk prospectively adopted FASB's Accounting Standards Update (“ASU”) 2013-11 regarding ASC Topic 740 “Income Tax.” This ASU clarifies the guidance on the presentation of an unrecognized tax benefit, or a portion of an unrecognized tax benefit, in the consolidated financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The adoption of this ASU resulted in an $81.9M reduction of both our long term taxes payable and long-term deferred tax assets as of January 31, 2015.
Recently Issued Accounting Standards
On May 28, 2014, the FASB issued ASU 2014-09 regarding ASC Topic 606 “Revenue from Contracts with Customers.” This ASU provides principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU will be effective for Autodesk’s fiscal year beginning February 1, 2017. Early adoption is not permitted. Autodesk is currently evaluating the accounting, transition, and disclosure requirements of the standard and cannot currently estimate the financial statement impact of adoption.

Financial_Instruments

Financial Instruments	12 Months Ended
	Jan. 31, 2015
Investments, All Other Investments [Abstract]
Financial Instruments	Financial Instruments
	The following tables summarize the Company's financial instruments' amortized cost, gross unrealized gains, gross unrealized losses, and fair value by significant investment category as of January 31, 2015 and 2014.
				January 31, 2015
				Amortized Cost				Gross unrealized gains				Gross unrealized losses				Fair Value		Level 1		Level 2		Level 3
	Cash equivalents (1):
		Corporate debt securities		$	258.6			$	—			$	—			$	258.6	$	258.6	$	—	$	—
		Custody cash deposit		141.5				—				—				141.5		141.5		—		—
		Commercial paper		161				—				—				161		—		161		—
		Corporate bond		11.5				—				—				11.5		11.5		—		—
		Money market funds		127.3				—				—				127.3		—		127.3		—
	Marketable securities:
		Short-term available for sale
			Agency bond	37.9				—				—				37.9		37.9		—		—
			Corporate debt securities	148				0.1				(0.1		)		148		148		—		—
			Municipal bond	29.2				0.1				—				29.3		29.3		—		—
			Certificate of deposit	101.9				—				—				101.9		101.9		—		—
			Commercial paper	258.4				—				—				258.4		—		258.4		—
		Short-term trading securities
			Mutual funds	36.9				3.4				—				40.3		40.3		—		—
		Long-term available for sale
			Agency bond	50.6				0.2				—				50.8		50.8		—		—
			Corporate debt securities	199.4				0.6				(0.2		)		199.8		199.8		—		—
			Municipal securities	13.3				0.1				—				13.4		13.4		—		—
			U.S. government agency securities	8.9				0.1				—				9		9		—		—
	Convertible debt securities (2)			4.7				2.5				(2.1		)		5.1		—		—		5.1
	Derivative contracts (3)			3.5				19.5				(7.0		)		16		—		15.1		0.9
			Total	$	1,592.60			$	26.6			$	(9.4	)		$	1,609.80	$	1,042.00	$	561.8	$	6
	____________________
	-1	Included in “Cash and cash equivalents” in the accompanying Consolidated Balance Sheets.
	-2	Considered "available for sale" and included in "Other assets" in the accompanying Consolidated Balance Sheets.
	-3	Included in “Prepaid expenses and other current assets,” "Other assets," or “Other accrued liabilities” in the accompanying Consolidated Balance Sheets.
				January 31, 2014
				Amortized Cost				Gross unrealized gains				Gross unrealized losses				Fair Value		Level 1		Level 2		Level 3
	Cash equivalents (1):
		Certificates of deposit and time deposits		$	280.7			$	—			$	—			$	280.7	$	30.4	$	250.3	$	—
		Municipal securities		2				—				—				2		2		—		—
		Commercial paper		280.5				—				—				280.5		—		280.5		—
		Money market funds		262.8				—				—				262.8		—		262.8		—
	Marketable securities:
		Short-term available for sale
			Commercial paper and corporate debt securities	261				—				—				261		95.4		165.6		—
			Time deposits	37.1				—				—				37.1		—		37.1		—
			U.S. government agency securities	11.3				—				—				11.3		11.3		—		—
			Agency bond	42.7				—				—				42.7		42.7		—		—
			Municipal securities	11.7				—				—				11.7		11.7		—		—
			Other (2)	11.4				—				—				11.4		11.4		—		—
		Short-term trading securities
			Mutual funds	35.6				3.3				—				38.9		38.9		—		—
		Long-term available for sale
			Corporate debt securities	179.7				0.7				(0.1		)		180.3		180.3		—		—
			Agency bond	43.3				0.1				—				43.4		43.4		—		—
			U.S. government agency securities	9.8				—				—				9.8		9.8		—		—
			Municipal securities	43.5				0.3				—				43.8		43.8		—		—
	Convertible Debt Securities (3)			21.4				3.2				(4.4		)		20.2		—		—		20.2
	Derivative contracts (4)			10.8				14.8				(6.0		)		19.6		—		10.5		9.1
			Total	$	1,545.30			$	22.4			$	(10.5	)		$	1,557.20	$	521.1	$	1,006.80	$	29.3
	____________________
	-1	Included in “Cash and cash equivalents” in the accompanying Consolidated Balance Sheets.
	-2	Consists of agency discount notes, U.S. treasury bills, and other short-term securities.
	-3	Considered "available for sale" securities and included in "Other assets" in the accompanying Consolidated Balance Sheets.
	-4	Included in “Prepaid expenses and other current assets,” "Other assets," or “Other accrued liabilities” in the accompanying Consolidated Balance Sheets.
	Autodesk classifies its marketable securities as either short-term or long-term based on each instrument’s underlying contractual maturity date. Marketable securities with remaining maturities of less than 12 months are classified as short-term and marketable securities with remaining maturities greater than 12 months are classified as long-term. Autodesk may sell certain of its marketable securities prior to their stated maturities for strategic purposes or in anticipation of credit deterioration.
	Autodesk applies fair value accounting for certain financial assets and liabilities, which consist of cash equivalents, marketable securities, and other financial instruments, on a recurring basis. The Company defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: (Level 1) observable inputs such as quoted prices in active markets; (Level 2) inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and (Level 3) unobservable inputs for which there is little or no market data, which require Autodesk to develop its own assumptions. When determining fair value, Autodesk uses observable market data and relies on unobservable inputs only when observable market data is not available. There have been no transfers between fair value measurement levels during the year ended January 31, 2015.
	Autodesk's cash equivalents, marketable securities, and financial instruments are primarily classified within Level 1 or Level 2 of the fair value hierarchy. Autodesk values it's available for sale securities on pricing from pricing vendors, who may use quoted prices in active markets for identical assets (Level 1) or inputs other than quoted prices that are observable either directly or indirectly in determining fair value (Level 2). Autodesk's Level 2 securities are valued primarily using observable inputs other than quoted prices in active markets for identical assets and liabilities. Autodesk's Level 3 securities consist of investments held in auction rate securities, convertible debt securities, and derivative contracts which are valued using probability weighted discounted cash flow models and some of the inputs to the models are unobservable in the market.
A reconciliation of the change in Autodesk’s Level 3 items for the fiscal years ended January 31, 2015 and 2014 was as follows:
	Fair Value Measurements Using
	Significant Unobservable Inputs
	(Level 3)
		Derivative Contracts				Convertible Debt Securities				Taxable Auction-Rate Securities				Total
Balance at January 31, 2013		$	10.7			$	17.5			$	4.2			$	32.4
Purchases		1.3				3.1				—				4.4
Settlements		—				—				(4.0		)		(4.0		)
Losses included in earnings (1)		(2.9		)		—				(0.2		)		(3.1		)
Losses included in OCI (1)		—				(0.4		)		—				(0.4		)
Balance at January 31, 2014		9.1				20.2				—				29.3
Purchases		0.1				0.6				—				0.7
Settlements		(0.8		)		(3.0		)		—				(3.8		)
Losses included in earnings		(7.5		)		(13.3		)		—				(20.8		)
Gains included in OCI		—				0.6				—				0.6
Balance at January 31, 2015		$	0.9			$	5.1			$	—			$	6
(1) For comparability, the presentation of prior period balances were adjusted to align with current year presentation.
The following table summarizes the estimated fair value of Autodesk's “available-for-sale securities” classified by the contractual maturity date of the security:
	January 31, 2015
	Cost				Fair Value
Due in 1 year	$	575.4			$	575.5
Due in 1 year through 5 years	276.9				278.1
Total	$	852.3			$	853.6
As of January 31, 2015 and 2014, Autodesk did not have any securities in a continuous unrealized loss position for greater than twelve months.
As of January 31, 2015 and 2014 Autodesk had $52.6 million and $49.8 million, respectively, in direct investments of privately held companies accounted for under the cost method, which are periodically assessed for other-than-temporary impairment. If Autodesk determines that an other-than-temporary impairment has occurred, Autodesk writes down the investment to its fair value. Autodesk estimates fair value of its cost method investments considering available information such as pricing in recent rounds of financing, current cash positions, earnings and cash flow forecasts, recent operational performance, and any other readily available market data. During fiscal 2015, Autodesk recorded $19.2 million in other-than-temporary impairments on its privately held equity investments. During fiscal 2014, Autodesk recorded no other-than-temporary impairment on its privately held equity investments. The impairment expense was recorded in “Interest and other (expense) income, net” on the Company's Consolidated Statement of Operations.
The sales or settlement of “available-for-sale securities” in fiscal 2015 and fiscal 2014 resulted in a gain of $0.7 million and a loss of $0.2 million, respectively. The sales or redemptions of “available-for-sale securities” in fiscal 2013 resulted in no gains or losses. The losses and gains were recorded in "Interest and other (expense) income, net" on the Company's Consolidated Statement of Operations.
Proceeds from the sale and maturity of marketable securities for fiscal 2015 and fiscal 2014 were $1,159.0 million and $1,279.1 million, respectively.
Derivative Financial Instruments
Under its risk management strategy, Autodesk uses derivative instruments to manage its short-term exposures to fluctuations in foreign currency exchange rates that exist as part of ongoing business operations. Autodesk's general practice is to hedge a portion of transaction exposures denominated in euros, Japanese yen, Swiss francs, British pounds, Canadian dollars and Australian dollars. These instruments have maturities between one to twelve months in the future. Autodesk does not enter into derivative instrument transactions for trading or speculative purposes.
The bank counterparties to the derivative contracts potentially expose Autodesk to credit-related losses in the event of their nonperformance. However, to mitigate that risk, Autodesk only contracts with counterparties who meet the Company's minimum requirements under its counterparty risk assessment process. Autodesk monitors ratings, credit spreads, and potential downgrades on at least a quarterly basis. Based on Autodesk's on-going assessment of counterparty risk, the Company will adjust its exposure to various counterparties. Autodesk generally enters into master netting arrangements, which reduce credit risk by permitting net settlement of transactions with the same counterparty.  However, Autodesk does not have any master netting arrangements in place with collateral features.
Foreign currency contracts designated as cash flow hedges
Autodesk uses foreign currency contracts to reduce the exchange rate impact on a portion of the net revenue or operating expense of certain anticipated transactions. These contracts are designated and documented as cash flow hedges. The effectiveness of the cash flow hedge contracts is assessed quarterly using regression analysis as well as other timing and probability criteria. To receive cash flow hedge accounting treatment, all hedging relationships are formally documented at the inception of the hedge and the hedges are expected to be highly effective in offsetting changes to future cash flows on hedged transactions. The gross gains and losses on these hedges are included in “Accumulated other comprehensive loss” and are reclassified into earnings at the time the forecasted revenue or expense is recognized. In the event the underlying forecasted transaction does not occur, or it becomes probable that it will not occur, Autodesk reclassifies the gain or loss on the related cash flow hedge from “Accumulated other comprehensive loss” to “Interest and other (expense) income, net” in the Company's Consolidated Financial Statements at that time.
The net notional amount of these contracts are presented net settled and were $336.6 million at January 31, 2015 and $351.7 million at January 31, 2014. Outstanding contracts are recognized as either assets or liabilities on the Consolidated Balance Sheet at fair value. The majority of the net gain of $42.8 million remaining in “Accumulated other comprehensive loss” as of January 31, 2015 is expected to be recognized into earnings within the next twelve months.
Derivatives not designated as hedging instruments
Autodesk uses foreign currency contracts which are not designated as hedging instruments to reduce the exchange rate risk associated primarily with foreign currency denominated receivables and payables. These forward contracts are marked-to-market at the end of each fiscal quarter with gains and losses recognized as “Interest and other (expense) income, net.” These derivative instruments do not subject the Company to material balance sheet risk due to exchange rate movements because gains and losses on these derivative instruments are intended to offset the gains or losses resulting from the settlement of the underlying foreign currency denominated receivables and payables. The net notional amounts of these foreign currency contracts are presented net settled and were $44.6 million at January 31, 2015 and $205.5 million at January 31, 2014.
From time to time and consistent with its risk management policy, Autodesk also uses derivative instruments to hedge its economic exposure related to committed, in-process acquisitions priced in foreign currency.  Such derivatives do not qualify for hedge accounting and are marked-to-market through earnings, with any gain or loss reflected immediately in “Interest and other (expense) income, net,” in each period.
In addition to these foreign currency contracts, Autodesk holds derivative instruments issued by privately held companies, which are not designated as hedging instruments. These derivatives consist of certain conversion options on the convertible debt securities held by Autodesk and an option to acquire a privately held company. These derivatives are recorded at fair value as of each balance sheet date and are recorded in “Other assets.” Changes in the fair values of these instruments are recognized in income as “Interest and other (expense) income, net.”
Fair Value of Derivative Instruments:
The fair value of derivative instruments in Autodesk’s Consolidated Balance Sheets were as follows as of January 31, 2015 and January 31, 2014:
	Balance Sheet Location		Fair Value at
			January 31, 2015				January 31, 2014
Derivative Assets
Foreign currency contracts designated as cash flow hedges	Prepaid expenses and other current assets (1)		$	20.4			$	4.4
Derivatives not designated as hedging instruments	Prepaid expenses and other current assets and Other assets		0.9				16.9
Total derivative assets			$	21.3			$	21.3
Derivative Liabilities
Foreign currency contracts designated as cash flow hedges	Other accrued liabilities (2)		$	5.4			$	1.7
Total derivative liabilities			$	5.4			$	1.7
_______________
-1	Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $23.8 million and $5.9 million at January 31, 2015 and January 31, 2014, respectively.
-2	Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $8.7 million and $3.2 million at January 31, 2015 and January 31, 2014, respectively.
The effects of derivatives designated as hedging instruments on Autodesk’s Consolidated Statements of Operations were as follows for the fiscal years ended January 31, 2015, 2014, and 2013, respectively (amounts presented include any income tax effects):
	Foreign Currency Contracts
	Fiscal Year Ended January 31,
	2015				2014				2013
Amount of gain recognized in accumulated other comprehensive income on derivatives (effective portion)	$	46.4			$	12.2			$	5.1
Amount and location of gain reclassified from accumulated other comprehensive income into income (effective portion)
Net revenue	$	10.5			$	13.1			$	16
Operating expenses	(3.5		)		(1.6		)		(4.6		)
Total	$	7			$	11.5			$	11.4
Amount and location of gain (loss) recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing)
Interest and other (expense) income, net	$	0.9			$	(0.1	)		$	(0.2	)
The effects of derivatives not designated as hedging instruments on Autodesk’s Consolidated Statements of Operations were as follows for the fiscal years ended January 31, 2015, 2014, and 2013, respectively (amounts presented include any income tax effects):
	Foreign Exchange Contracts
	Fiscal Year Ended January 31,
	2015				2014				2013
Amount and location of (loss) gain recognized in income on derivative
Interest and other (expense) income, net	$	(25.5	)		$	12.8			$	1.5

Employee_and_Director_Stock_Pl

Employee and Director Stock Plans	12 Months Ended
	Jan. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Employee and Director Stock Plans	Employee and Director Stock Plans
	Stock Plans
	As of January 31, 2015, Autodesk maintained two active stock plans for the purpose of granting equity awards to employees and to non-employee members of Autodesk’s Board of Directors: the 2012 Employee Stock Plan (as amended, the “2012 Employee Plan”), which is available only to employees, and the Autodesk 2012 Outside Directors’ Stock Plan (“2012 Directors' Plan”), which is available only to non-employee directors. Additionally, there are three expired or terminated plans with options outstanding. The exercise price of all stock options granted under these plans was equal to the fair market value of the stock on the grant date.
	The 2012 Employee Plan was approved by Autodesk's stockholders and became effective on January 6, 2012. On January 14, 2014, Autodesk's stockholders approved amendments to the 2012 Employee Plan, which increased the number of shares reserved for issuance under the plan by 11.4 million shares and added additional performance goals to the plan. The 2012 Employee Plan replaced the 2008 Employee Stock Plan, as amended ("2008 Plan"), and no further equity awards may be granted under the 2008 Plan. The 2012 Employee Plan reserves up to 32.6 million shares which includes 26.6 million shares reserved under the 2012 Employee Plan, as well as up to 6.0 million shares forfeited under certain prior employee stock plans during the life of the 2012 Employee Plan. The 2012 Employee Plan permits the grant of stock options, restricted stock units, and restricted stock awards. Each restricted stock unit or restricted stock award granted will be counted against the shares authorized for issuance under the 2012 Employee Plan as 1.79 shares. If a granted option, restricted stock unit, or restricted stock award expires or becomes unexercisable for any reason, the unpurchased or forfeited shares that were granted may be returned to the 2012 Employee Plan and may become available for future grant under the 2012 Employee Plan. As of January 31, 2015, 22.1 million shares subject to options or restricted stock awards have been granted under the 2012 Employee Plan. Options and restricted stock that were granted under the 2012 plan vest over periods ranging from immediately upon grant to over a three year period and options expire 10 years from the date of grant. The 2012 Employee Plan will expire on June 30, 2022. At January 31, 2015, 12.3 million shares were available for future issuance under the 2012 Employee Plan.
	The 2012 Director's Plan was approved by Autodesk's stockholders and became effective on January 6, 2012. The 2012 Directors' Plan replaced the 2010 Outside Directors' Stock Plan, as amended ("2010 Plan"). The 2012 Directors' Plan permits the grant of stock options, restricted stock units, and restricted stock awards to non-employee members of Autodesk’s Board of Directors. Each restricted stock unit or restricted stock award granted will be counted against the shares authorized for issuance under the 2012 Directors' Plan as 2.11 shares. As of January 31, 2015, 0.6 million shares subject to restricted stock unit awards have been granted under the 2012 Directors' Plan. Restricted stock units that were granted under the 2012 Outside Directors' Plan vest over one to three years from the date of grant. The 2012 Directors' Plan reserved 2.6 million shares of Autodesk common stock. The 2012 Directors' Plan will expire on June 30, 2022. At January 31, 2015, 2.0 million shares were available for future issuance under the 2012 Director's Plan.
	The following sections summarize activity under Autodesk’s stock plans.
	Stock Options:
	A summary of stock option activity for the fiscal year ended January 31, 2015 is as follows:
		Number of Shares		Weighted average exercise price per share				Weighted average remaining contractual term		Aggregate Intrinsic Value (3)
		(in millions)						(in years)		(in millions)
	Options outstanding at January 31, 2014	5.9		$	33.54
	Granted (1)	—		—
	Exercised	(3.2	)	32.76
	Canceled/Forfeited	—		—
	Options outstanding at January 31, 2015	2.7		$	34.46			4.2		$	53.1
	Options vested and exercisable at January 31, 2015	2.5		$	33.72			3.9		$	49.9
	Options vested and exercisable as of January 31, 2015 and expected to vest thereafter (2)	2.7		$	34.46			4.2		$	53.1
	Options available for grant at January 31, 2015	14.3
	_______________
	-1	Autodesk did not grant stock options in the twelve months ended January 31, 2015.
	-2	Options expected to vest reflect an estimated forfeiture rate.
	-3	Represents the total pre-tax intrinsic value, based on Autodesk’s closing stock price of $54.01 per share as of January 31, 2015, which would have been received by the option holders had all option holders exercised their options as of that date.
	As of January 31, 2015, compensation cost of $0.6 million related to non-vested options is expected to be recognized over a weighted average period of 0.2 years.
	The following table summarizes information about the pre-tax intrinsic value of options exercised and the weighted average grant date fair value per share of options granted during the fiscal years ended January 31, 2015, 2014, and 2013:
		Fiscal year ended January 31,
		2015			2014				2013
	Intrinsic value of options exercised (1)	$	67.6		$	149			$	90.9
	Weighted average grant date fair value per share of stock options granted (2)	$	—		$	—			$	13.4
	——————
	-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 Black-Scholes Merton ("BSM") option pricing model. For the twelve months ended January 31, 2015 and 2014, Autodesk did not grant stock options.
	The following table summarizes information about options vested and exercisable, and outstanding at January 31, 2015:
		Options Vested and Exercisable										Options Outstanding
		Number of Shares (in millions)		Weighted average contractual life (in years)		Weighted average exercise price per share				Aggregate intrinsic value(1) (in millions)		Number of Shares (in millions)	Weighted average contractual life (in years)	Weighted average exercise price per share		Aggregate intrinsic value(1) (in millions)
	Range of per-share exercise prices:
	$12.31 - $29.49	0.9				$	23.76					0.9		$	23.83
	$29.50 - $41.62	1.2				38.73						1.3		38.85
	$42.39 - $43.81	0.4				43.8						0.5		43.79
		2.5		3.9		$	33.72			$	49.9	2.7	4.2	$	34.46	$	53.1
	____________________
	-1	Represents the total pre-tax intrinsic value, based on Autodesk’s closing stock price of $54.01 per share as of January 31, 2015, which would have been received by the option holders had all option holders exercised their options as of that date.
	These options will expire if not exercised at specific dates ranging through September 2022.
	Restricted Stock:
	A summary of restricted stock unit activity for the fiscal year ended January 31, 2015 is as follows:
		Unreleased Restricted Stock Units		Weighted average grant date fair value
		(in thousands)
	Unreleased restricted stock units at January 31, 2014	6,515.60		$	39.15
	Granted	4,481.80		54.17
	Vested	(2,675.6	)	37.36
	Canceled/Forfeited	(445.8	)	41.43
	Performance Adjustment (1)	(74.7	)	42.23
	Unreleased restricted stock units at January 31, 2015	7,801.30		$	48.46
	_______________
	-1	Based on Autodesk's financial results for the performance period, the fiscal 2014 and 2013 performance stock units were earned at 65.8% and 92.3% of the target award, respectively. The vesting of the performance stock units is subject to the holders satisfying the remaining service condition of the awards.
	For the restricted stock units granted during fiscal years ended January 31, 2015, 2014, and 2013, the weighted average grant date fair value was $54.17, $42.37, and $33.32, respectively. The grant date fair value of the shares vested during fiscal years ended January 31, 2015, 2014, and 2013 was $100.0 million, $73.8 million, and $33.6 million, respectively.
	During the fiscal year ended January 31, 2015, Autodesk granted 4.0 million restricted stock units. The restricted stock units vest over periods ranging from immediately upon grant to a pre-determined date that is typically within three years from the date of grant. Restricted stock units are not considered outstanding stock at the time of grant, as the holders of these units are not entitled to any of the rights of a stockholder, including voting rights. The fair value of the restricted stock units is expensed ratably over the vesting period. Autodesk recorded stock-based compensation expense related to restricted stock units of $118.9 million, $74.9 million, and $70.5 million during fiscal years ended January 31, 2015, 2014, and 2013, respectively. Included in the $70.5 million incurred in fiscal 2013, Autodesk incurred $16.6 million relating to the acceleration of vesting of equity awards held in Socialcam for Socialcam employees immediately prior to the acquisition. As of January 31, 2015, total compensation cost not yet recognized of $245.0 million related to non-vested awards, is expected to be recognized over a weighted average period of 1.8 years. At January 31, 2015, the number of restricted stock units granted but unvested was 6.9 million.
	During the fiscal year ended January 31, 2015, Autodesk granted 0.5 million performance stock units ("PSUs") for which the ultimate number of shares earned is determined based on the achievement of performance criteria at the end of the stated performance period. The performance criteria are based upon billings and subscriptions goals adopted by the Compensation and Human Resource Committee (the “Annual Financial Results”), as well as total stockholder return compared against the S&P Computer Software Select Index (“Relative TSR”). Each PSU covers a three year period:
	•	Up to one third of the PSU may vest following year one depending upon the achievement of Annual Financial Results for year one as well as 1 year Relative TSR (covering year one).
	•	Up to one third of the PSU may vest following year two depending upon the achievement of Annual Financial Results for year two as well as 2 year Relative TSR (covering years one and two).
	•	Up to one third of the PSU may vest following year three depending upon the achievement of Annual Financial Results for year three as well as 3 year Relative TSR (covering years one, two, and three).
	PSUs are not considered outstanding stock at the time of grant, as the holders of these units are not entitled to any of the rights of a stockholder, including voting rights. Autodesk has determined the grant-date fair value for these awards using a Monte Carlo simulation model since the awards are subject to a market condition. The fair value of the performance restricted stock units is expensed using the accelerated attribution method over the vesting period. Autodesk recorded stock-based compensation expense related to PSUs of $17.5 million, $8.7 million, and $8.1 million during fiscal year ended January 31, 2015, 2014, and 2013 respectively. As of January 31, 2015, total compensation cost not yet recognized of $2.5 million related to non-vested PSUs, is expected to be recognized over a weighted average period of 0.8 years. At January 31, 2015, the number of PSUs granted but unvested was 0.9 million.
	1998 Employee Qualified Stock Purchase Plan (“ESP Plan”)
	Under Autodesk’s ESP Plan, which was approved by stockholders in 1998, eligible employees may purchase shares of Autodesk’s common stock at their discretion using up to 15% of their eligible compensation subject to certain limitations, at not less than 85% of fair market value as defined in the ESP Plan. At January 31, 2015, a total of 40.7 million shares were available for future issuance. This amount automatically increases on the first trading day of each fiscal year by an amount equal to the lesser of 10.0 million shares or 2% of the total of (1) outstanding shares plus (2) any shares repurchased by Autodesk during the prior fiscal year. Under the ESP Plan, the Company issues shares on the first trading day following March 31 and September 30 of each fiscal year. The ESP Plan expires during fiscal 2018.
	Autodesk issued 2.1 million shares under the ESP Plan at an average price of $33.91 per share in fiscal 2015, 2.9 million shares at an average price of $22.61 per share in fiscal 2014, and 2.9 million shares at an average price of $21.79 per share in fiscal 2013. The weighted average grant date fair value of awards granted under the ESP Plan during fiscal 2015, 2014, and 2013, calculated as of the award grant date using the BSM option pricing model, was $15.14, $11.80, and $12.21 per share, respectively. Autodesk recorded $23.9 million, $22.9 million, and $34.0 million of compensation expense associated with the ESP Plan in fiscal 2015, 2014, and 2013, respectively.
Equity Compensation Plan Information
The following table summarizes the number of outstanding options granted to employees and directors, as well as the number of securities remaining available for future issuance under these plans as of January 31, 2015:
	(a)		(b)				(c)
Plan category	Number of securities to be issued upon exercise of outstanding options		Weighted-average exercise price of outstanding options				Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column (a)) (in millions)
Equity compensation plans approved by security holders	10.5		$	34.46			55		-1
Total	10.5		$	34.46			55
____________________
-1	Included in this amount are 40.7 million securities available for future issuance under Autodesk’s ESP Plan.

Income_Taxes

Income Taxes	12 Months Ended
	Jan. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	The provision for income taxes consists of the following:
		Fiscal year ended January 31,
		2015			2014			2013
	Federal:
	Current	$	(43.8	)	$	29.1		$	30.9
	Deferred	(11.9		)	(41.4		)	(13.3		)
	State:
	Current	(13.2		)	0.6			7.8
	Deferred	9			—			(18.6		)
	Foreign:
	Current	69.5			63.9			54.3
	Deferred	(8.4		)	(1.1		)	1.5
		$	1.2		$	51.1		$	62.6
	During fiscal year 2015, the Company reduced its current federal and state taxes payable by $0.5 million related to excess tax benefits from non-qualified stock options, offsetting additional paid-in capital. Pursuant to accounting standards related to stock-based compensation, the Company has unrecorded excess stock option tax benefits of $217.9 million as of January 31, 2015. These amounts will be credited to additional paid-in-capital when such amounts reduce cash taxes payable. Foreign pretax income was $302.5 million in fiscal 2015, $380.5 million in fiscal 2014, and $383.3 million in fiscal 2013.
	The differences between the U.S. statutory rate and the aggregate income tax provision are as follows:
		Fiscal year ended January 31,
		2015			2014			2013
	Income tax provision at U.S. Federal statutory rate	$	29		$	98		$	108.5
	State income tax benefit, net of the U.S. Federal benefit	(4.0		)	(2.9		)	(1.7		)
	Foreign income taxed at rates different from the U.S. statutory rate	(40.0		)	(57.1		)	(54.5		)
	U.S. valuation allowance	2.9			2.1			1.7
	Tax effect of non-deductible stock-based compensation	15.7			10.8			21.1
	Research and development tax credit benefit	(7.2		)	(8.8		)	(7.0		)
	Tax (benefit) expense from closure of income tax audits and changes in uncertain tax positions	(0.7		)	3.6			(2.8		)
	Tax effect of officer compensation in excess of $1.0 million	2.4			3			1.8
	U.S. Manufacturer's deduction	—			(0.1		)	(4.9		)
	Other	3.1			2.5			0.4
		$	1.2		$	51.1		$	62.6
	Significant components of Autodesk’s deferred tax assets and liabilities are as follows:
		January 31,
		2015			2014
	Stock-based compensation	$	39.9		$	37.4
	Research and development tax credit carryforwards	62.6			78.4
	Foreign tax credit carryforwards	—			16.3
	Accrued compensation and benefits	43.6			38.6
	Other accruals not currently deductible for tax	18.4			14.5
	Purchased technology and capitalized software	13.2			23.4
	Fixed assets	16.2			17.5
	Tax loss carryforwards	16			12.6
	Deferred Revenue	48			33.1
	Other	7.4			5.1
	Total deferred tax assets	265.3			276.9
	Less: valuation allowance	(70.8		)	(67.2		)
	Net deferred tax assets	194.5			209.7
	Unremitted earnings of foreign subsidiaries	(9.4		)	(21.8		)
	Total deferred tax liability	(9.4		)	(21.8		)
	Net deferred tax assets	$	185.1		$	187.9
	Effective February 1, 2014, Autodesk prospectively adopted FASB's Accounting Standards Update (“ASU”) 2013-11
	regarding ASC Topic 740 “Income Tax.”  This ASU clarifies the guidance on the presentation of an unrecognized tax benefit, or a portion of an unrecognized tax benefit, in the consolidated financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. Research and development tax credit carryforwards and foreign tax credit carryforwards as of January 31, 2015 have been reduced by unrecognized tax benefits to the extent the tax credit carryforwards would be expected to offset tax liabilities in the event the uncertain tax positions are disallowed.
	The valuation allowance increased by $3.6 million, $15.9 million, and $3.8 million in fiscal 2015, 2014, and 2013, respectively. The fiscal 2015, 2014, and 2013 changes in valuation allowance were primarily related to U.S. and Canadian deferred taxes.
	Autodesk provides U.S. income taxes on the earnings of foreign subsidiaries, except to the extent subsidiaries' earnings are considered permanently reinvested outside the U.S. As of January 31, 2015, the cumulative amount of earnings upon which U.S. income taxes have not been provided was $1,809.4 million. The unrecognized deferred tax liability for these earnings was approximately $514.4 million.
	Realization of the net deferred tax assets of $185.1 million is dependent upon the company's ability to generate future taxable income in appropriate tax jurisdictions to obtain benefit from the reversal of temporary differences, net operating loss carryforwards and tax credits. The amount of deferred tax assets considered realizable is subject to adjustment in future periods if estimates of future taxable income are reduced and Autodesk then determines that it is not more likely than not to realize such deferred tax assets.
	As of January 31, 2015, Autodesk had $21.7 million of cumulative federal tax loss carryforwards and $354.3 million of cumulative state tax loss carryforwards, which may be available to reduce future income tax liabilities in certain jurisdictions. These federal and state tax loss carryforwards will expire beginning fiscal 2015 through fiscal 2034 and fiscal 2015 through fiscal 2034, respectively. Autodesk also had $7.4 million of cumulative UK tax loss carryforwards, which may be available to reduce future income tax liabilities indefinitely. Autodesk had $9.2 million of cumulative federal and state capital loss carryforwards as of January 31, 2015 which are available to offset future capital gains through fiscal 2018.
	As of January 31, 2015, Autodesk had $104.7 million of cumulative federal research tax credit carryforwards, $54.8 million of cumulative California state research tax credit carryforwards, and $59.8 million of cumulative Canadian federal tax credit carryforwards, which may be available to reduce future income tax liabilities in the respective jurisdictions. The federal credit carryforwards will expire beginning fiscal 2020 through fiscal 2035, the state credit carryforwards may reduce future California income tax liabilities indefinitely, and the Canadian tax credit carryforwards will expire beginning fiscal 2024 through fiscal 2034. Autodesk also has $163.6 million of cumulative foreign tax credit carryforwards, which may be available to reduce future U. S. tax liabilities. The foreign tax credit will expire beginning fiscal 2019 through fiscal 2026.
	Utilization of net operating losses and tax credits may be subject to an annual limitation due to ownership change limitations provided in the Internal Revenue Code and similar state provisions. This annual limitation may result in the expiration of net operating losses and credits before utilization.
	As a result of certain business and employment actions and capital investments undertaken by Autodesk, income earned in certain Europe and Asia Pacific countries is subject to reduced tax rates through fiscal 2016 and 2020, respectively with extensions available with incremental business and employment actions. The net income tax benefits attributable to the tax status of these business arrangements are estimated to be $1.2 million ($0.01 basic net income per share) in fiscal 2015, $9.7 million ($0.04 basic net income per share) in fiscal 2014, and $6.6 million ($0.03 basic net income per share) in fiscal 2013. The income tax benefits were offset partially by accruals of U.S. income taxes on undistributed earnings, among other factors.
	As of January 31, 2015, the company had $245.8 million of gross unrecognized tax benefits, of which $227.3 million would impact the effective tax rate, if recognized. It is possible that the amount of unrecognized tax benefits will change in the next twelve months; however an estimate of the range of the possible change cannot be made at this time.
	A reconciliation of the beginning and ending amount of the gross unrecognized tax benefits is as follows:
		Fiscal Year Ended January 31,
		2015			2014			2013
	Gross unrecognized tax benefits at the beginning of the fiscal year	$	222.1		$	212.7		$	201.1
	Increases for tax positions of prior years	3.2			1.8			0.4
	Decreases for tax positions of prior years	(2.5		)	(0.3		)	(0.4		)
Increases for tax positions related to the current year	33.2			15.3			17.8
Decreases relating to settlements with taxing authorities	(5.4		)	(4.6		)	(3.0		)
Reductions as a result of lapse of the statute of limitations	(4.8		)	(2.8		)	(3.2		)
Gross unrecognized tax benefits at the end of the fiscal year	$	245.8		$	222.1		$	212.7
It is the company's continuing practice to recognize interest and/or penalties related to income tax matters in income tax expense. Autodesk had $2.0 million, $2.8 million, and $1.9 million, net of tax benefit, accrued for interest and an immaterial amount accrued for penalties related to unrecognized tax benefits as of January 31, 2015, 2014, and 2013, respectively.
Autodesk and its subsidiaries are subject to income tax in the United States as well as numerous state and foreign jurisdictions. Autodesk's U.S. and state income tax returns for fiscal year 2003 through fiscal year 2015 remain open to examination. In addition, Autodesk files tax returns in multiple foreign taxing jurisdictions with open tax years ranging from fiscal year 2003 to 2015.

Acquisitions

Acquisitions	12 Months Ended
	Jan. 31, 2015
Business Combinations [Abstract]
Acquisitions	Acquisitions
	During the fiscal years ended January 31, 2015 and January 31, 2014, Autodesk completed the business combinations and technology purchases described below. The results of operations for the following acquisitions are included in the accompanying Consolidated Statement of Operations since their respective acquisition dates. Pro forma results of operations have not been presented because the effects of the following acquisitions, individually and in the aggregate, were not material to Autodesk's Consolidated Financial Statements.
	For acquisitions accounted for as business combinations, Autodesk recorded the tangible and intangible assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. The fair values assigned to the identifiable intangible assets acquired were based on estimates and assumptions determined by management. Autodesk recorded the excess of consideration transferred over the aggregate fair values as goodwill.
	Fiscal 2015 Acquisitions
	On June 27, 2014, Autodesk acquired Shotgun Software, Inc. (“Shotgun”) for total consideration of $54.5 million, of which $51.2 million was cash consideration. Prior to acquiring Shotgun, Autodesk had a convertible debt investment in the company with an acquisition-date fair value of $3.3 million using a market approach to value the investment. Shotgun was a privately-owned company that provided a cloud-based production management solution that enabled digital studios to track, schedule, review, and collaborate on projects and images. Shotgun has been integrated into, and the related goodwill was assigned to, Autodesk's M&E segment. Goodwill is not expected to be deductible for U.S. income tax purposes.
	On May 29, 2014, Autodesk acquired all the outstanding shares of Within Technologies Limited ("Within Technologies”) for total cash consideration of $88.0 million. Autodesk used its non-U.S.-based cash for the transaction. Within Technologies is a United Kingdom based developer of design and simulation software for next generation manufacturing processes.  The Within Technologies acquisition is expected to accelerate Autodesk’s development of tools and technologies for advanced manufacturing.  Within Technologies has been integrated into Autodesk’s PSEB reportable segment. The amount of goodwill that is expected to be deductible for U.S. income tax purposes is $78.9 million.
	On February 6, 2014, Autodesk acquired the entire issued and to be issued share capital of Delcam plc (“Delcam”), for $284.6 million. Delcam was previously listed as a public company (LON: DLC) and is a leading supplier of advanced CADCAM and industrial measurement solutions for the manufacturing industry. With this transaction Autodesk gains Delcam’s range of design, manufacturing, and inspection software that provide automated CADCAM solutions for a variety of industries, ranging from aerospace to toys and sports equipment. The transaction was structured as a cash offer for all the outstanding shares of Delcam, and Delcam has been integrated into Autodesk's MFG reportable segment. The amount of goodwill that is expected to be deductible for U.S. income tax purposes is $166.0 million.
	During the fiscal year ended January 31, 2015, Autodesk also completed 21 other business combination and technology acquisitions for total cash consideration of $234.5 million. These business combinations and technology acquisitions were not material individually or in aggregate to Autodesk's Consolidated Financial Statements.
	The following table summarizes the fair value of the assets acquired and liabilities assumed by major class for each of the business combinations and technology acquisitions completed during the fiscal year ended January 31, 2015:
		Shotgun			Within			Delcam			Other
	Developed technologies	$	5.4		$	4.6		$	28.9		$	39
	Customer relationships and other non-current intangible assets	7.5			3.6			39.7			9.8
	Trade name	1.6			1.2			16.5			6.3
	Goodwill	43.2			80.6			190.4			180.6
	Deferred Revenue (current and non-current)	(0.7		)	—			(10.4		)	(0.4		)
	Deferred tax liability	(2.6		)	(1.7		)	(13.2		)	(2.1		)
	Net tangible assets (liabilities)	0.1			(0.3		)	32.7			1.3
		$	54.5		$	88		$	284.6		$	234.5
	For Shotgun and certain other business combinations, the allocation of purchase price consideration to certain assets and liabilities is not yet finalized. Autodesk's estimates and assumptions are subject to change within the measurement period (up to one year from the acquisition date). The primary areas of the preliminary purchase price allocation that are not yet finalized are amounts for tax assets and liabilities, pending finalization of estimates and assumptions in respect of certain tax aspects of the transaction and residual goodwill.
	Fiscal 2014 Acquisitions
	On November 21, 2013, Autodesk acquired all of the outstanding shares of Graitec SA (“Graitec”) for total cash consideration of $87.0 million.  The acquisition enhances Autodesk’s current offerings for structural engineering and expands our portfolio of technology for Building Information Modeling ("BIM") for structural fabrication and detailing. Graitec has been integrated into Autodesk’s AEC segment. The amount of goodwill that is deductible for U.S. income tax purposes is $64.1 million.
	During the fiscal year ended January 31, 2014, Autodesk also completed 14 other business combination and technology acquisitions for total cash consideration of approximately $89.7 million. These business combinations and technology acquisitions were not material individually or in aggregate to Autodesk's Consolidated Financial Statements.
	The following table summarizes the fair value of the assets acquired and liabilities assumed by major class for each of the business combinations and technology acquisitions completed during the fiscal year ended January 31, 2014:
		Graitec			Other
	Developed technologies	$	15.9		$	15.9
	Customer relationships	2.2			2.8
	Trade name	1.7			1.8
	Goodwill	73.4			67
	Deferred tax (liability) asset	(6.2		)	0.7
	Net tangible assets	—			1.5
	Total	$	87		$	89.7

Deferred_Compensation

Deferred Compensation	12 Months Ended
	Jan. 31, 2015
Compensation Related Costs [Abstract]
Deferred Compensation	Deferred Compensation
	At January 31, 2015, Autodesk had marketable securities totaling $888.8 million, of which $40.3 million related to investments in debt and equity securities that are held in a rabbi trust under non-qualified deferred compensation plans. The total related deferred compensation liability was $40.3 million at January 31, 2015, of which $5.3 million was classified as current and $35.0 million was classified as non-current liabilities. The value of debt and equity securities held in the rabbi trust at January 31, 2014 was $38.9 million. The total related deferred compensation liability at January 31, 2014 was $38.9 million, of which $1.9 million was classified as current and $37.0 million was classified as non-current liabilities. The securities are recorded in the Consolidated Balance Sheets under the current portion of "Marketable Securities". The current and non-current portions of the liability are recorded in the Consolidated Balance Sheets under “Accrued compensation” and “Other liabilities,” respectively.

Borrowing_Arrangements

Borrowing Arrangements	12 Months Ended
	Jan. 31, 2015
Debt Disclosure [Abstract]
Borrowing Arrangements	Borrowing Arrangements
	In December 2012, Autodesk issued $400.0 million aggregate principal amount of 1.95% senior notes due December 15, 2017 and $350.0 million aggregate principal amount of 3.6% senior notes due December 15, 2022, (collectively, the "Senior Notes"). Autodesk received net proceeds of $739.3 million from issuance of the Senior Notes, net of a discount of $4.5 million and issuance costs of $6.1 million. Both the discount and issuance costs are being amortized to interest expense over the respective terms of the Senior Notes using the effective interest method. The proceeds of the Senior Notes are available for general corporate purposes. Autodesk may redeem the Senior Notes at any time, subject to a make whole premium. In addition, upon the occurrence of certain change of control triggering events, Autodesk may be required to repurchase the Senior Notes, at a price equal to 101% of their principal amount, plus accrued and unpaid interest to the date of repurchase. The Senior Notes contain restrictive covenants that limit our ability to create certain liens, to enter into certain sale and leaseback transactions and to consolidate or merge with, or convey, transfer, or lease all or substantially all of our assets, subject to significant qualifications and exceptions. Based on quoted market prices, the fair value of the Senior Notes was approximately $759.9 million as of January 31, 2015.
	Autodesk’s line of credit facility permits unsecured short-term borrowings of up to $400.0 million with an option to request an increase in the amount of the credit facility by up to an additional $100.0 million, and is available for working capital or other business needs. This credit agreement contains customary covenants that could restrict the imposition of liens on Autodesk’s assets, and restrict the Company’s ability to incur additional indebtedness or make dispositions of assets if Autodesk fails to maintain the financial covenants. The financial covenants consist of a leverage ratio, and an interest coverage ratio. The line of credit is syndicated with various financial institutions, including Citibank, N.A., an affiliate of Citigroup, which is one of the lead lenders and an agent. As of January 31, 2015, we were in compliance with the credit facility’s covenants. The credit facility expires in May 2018. At January 31, 2015 and January 31, 2014, Autodesk had no outstanding borrowings on this line of credit.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Jan. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Lease commitments
	Autodesk leases office space and computer equipment under non-cancellable operating lease agreements that expire at various dates through 2088. The leases generally provide that Autodesk pay taxes, insurance, and maintenance expenses related to the leased assets. Certain of these lease arrangements contain escalation clauses whereby monthly rent increases over time. At January 31, 2015, the aggregate future minimum lease payments required were as follows:
	2016	$	55.4
	2017	47.3
	2018	40.7
	2019	29.1
	2020	19.5
	Thereafter	32.6
		224.6
	Less: Sublease income	1.9
		$	222.7
	Rent expense related to these operating leases recognized on a straight-line basis over the lease period, was as follows:
		Fiscal Year Ended January 31,
		2015		2014		2013
	Rent expense	$	55	$	50.2	$	56.1
	Purchase commitments
	In the normal course of business, Autodesk enters into various purchase commitments for goods or services. Total non-cancellable purchase commitments as of January 31, 2015 were approximately $85.4 million for periods through fiscal 2020. These purchase commitments primarily result from contracts for the acquisition of IT infrastructure, marketing, and software development services.
	Autodesk has certain royalty commitments associated with the shipment and licensing of certain products. Royalty expense is generally based on a dollar amount per unit shipped or a percentage of the underlying revenue. Royalty expense, which was recorded under cost of license and other revenue on Autodesk’s Consolidated Statements of Operations, was $17.9 million in fiscal 2015, $18.0 million in fiscal 2014, and $16.4 million in fiscal 2013.
	Guarantees and Indemnifications
	In the normal course of business, Autodesk provides indemnifications of varying scopes, including limited product warranties and indemnification of customers against claims of intellectual property infringement made by third parties arising from the use of its products or services. Autodesk accrues for known indemnification issues if a loss is probable and can be reasonably estimated. Historically, costs related to these indemnifications have not been significant, and because potential future costs are highly variable, Autodesk is unable to estimate the maximum potential impact of these indemnifications on its future results of operations.
	In connection with the purchase, sale, or license of assets or businesses with third parties, Autodesk has entered into or assumed customary indemnification agreements related to the assets or businesses purchased, sold or licensed. Historically, costs related to these indemnifications have not been significant, and because potential future costs are highly variable, Autodesk is unable to estimate the maximum potential impact of these indemnifications on its future results of operations.
	As permitted under Delaware law, Autodesk has agreements whereby it indemnifies its officers and directors for certain events or occurrences while the officer or director is, or was, serving at Autodesk’s request in such capacity. The maximum potential amount of future payments Autodesk could be required to make under these indemnification agreements is unlimited; however, Autodesk has directors’ and officers’ liability insurance coverage that is intended to reduce its financial exposure and may enable Autodesk to recover a portion of any future amounts paid. Autodesk believes the estimated fair value of these indemnification agreements in excess of applicable insurance coverage is minimal.
	Legal Proceedings
	Autodesk is involved in a variety of claims, suits, investigations, and proceedings in the normal course of business activities including claims of alleged infringement of intellectual property rights, commercial, employment, piracy prosecution, business practices, and other matters. In the Company's opinion, resolution of pending matters is not expected to have a material adverse impact on its consolidated results of operations, cash flows, or its financial position. Given the unpredictable nature of legal proceedings, there is a reasonable possibility that an unfavorable resolution of one or more such proceedings could in the future materially affect the Company's results of operations, cash flows, or financial position in a particular period, however, based on the information known by the Company as of the date of this filing and the rules and regulations applicable to the preparation of the Company's financial statements, any such amount is either immaterial or it is not possible to provide an estimated amount of any such potential loss.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Jan. 31, 2015
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity
	Preferred Stock
	Under Autodesk’s Certificate of Incorporation, 2.0 million shares of preferred stock are authorized. At January 31, 2015, there were no preferred shares issued or outstanding. The Board of Directors has the authority to issue the preferred stock in one or more series and to fix rights, preferences, privileges, and restrictions, including dividends and the number of shares constituting any series or the designation of such series, without any further vote or action by the stockholders.
	Common Stock Repurchase Programs
	Autodesk has a stock repurchase program that is used to offset dilution from the issuance of stock under the Company’s employee stock plans and for such other purposes as may be in the interests of Autodesk and its stockholders, which has the effect of returning excess cash generated from the Company’s business to stockholders. Autodesk repurchased and retired 6.9 million shares in fiscal 2015 at an average repurchase price of $53.83 per share, 10.5 million shares in fiscal 2014 at an average repurchase price of $40.43 per share, and 12.5 million shares in fiscal 2013 at an average repurchase price of $34.50.
	At January 31, 2015, 14.8 million shares remained available for repurchase under the repurchase program approved by the Board of Directors. The number of shares acquired and the timing of the purchases are based on several factors, including general market and economic conditions, the number of employee stock option exercises and stock issuances, the trading price of Autodesk common stock, cash on hand and available in the United States, cash requirements for acquisitions, and Company defined trading windows.

Interest_And_Other_Income_net

Interest And Other Income, net	12 Months Ended
	Jan. 31, 2015
Interest and Other Income, net [Abstract]
Interest and Other (Expense) Income, net	Interest and Other (Expense) Income, net
	Interest and other (expense) income, net, consists of the following:
		Fiscal Year Ended January 31,
		2015			2014			2013
	Interest and investment (expense) income, net	$	(13.2	)	$	(9.8	)	$	4.9
	(Loss) gain on foreign currency	(3.9		)	4			1.2
	Loss on strategic investments	(23.3		)	(1.8		)	(4.0		)
	Other income	2.7			2.7			2
	Interest and other (expense) income, net	$	(37.7	)	$	(4.9	)	$	4.1

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss	12 Months Ended
	Jan. 31, 2015
Accumulated Other Comprehensive Income (loss) [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss
	Accumulated other comprehensive loss, net of taxes, was comprised of the following:
		Net Unrealized Gains (Losses) on Derivative Instruments			Net Unrealized Gains (Losses) on Available for Sale Securities			Defined Benefit Pension Components			Foreign Currency Translation Adjustments			Total (1)
	Balances, January 31, 2013	$	2.8		$	2.9		$	(13.1	)	$	1.7		$	(5.7	)
	Other comprehensive income (loss) before reclassifications	11.1			(0.2		)	3.9			(2.0		)	12.8
	Pre-tax (gains) losses reclassified from accumulated other comprehensive income	(11.5		)	(1.2		)	0.9			—			(11.8		)
	Tax effects	1.1			0.3			0.6			2.1			4.1
	Net current period other comprehensive income (loss)	0.7			(1.1		)	5.4			0.1			5.1
	Balances, January 31, 2014	3.5			1.8			(7.7		)	1.8			(0.6		)
	Other comprehensive income (loss) before reclassifications	47			(1.7		)	(18.3		)	(80.7		)	(53.7		)
	Pre-tax (gains) losses reclassified from accumulated other comprehensive income	(7.0		)	1.7			0.5			—			(4.8		)
	Tax effects	(0.7		)	(0.2		)	1.8			4.9			5.8
	Net current period other comprehensive income (loss)	39.3			(0.2		)	(16.0		)	(75.8		)	(52.7		)
	Balances, January 31, 2015	$	42.8		$	1.6		$	(23.7	)	$	(74.0	)	$	(53.3	)
	(1) For comparability, the presentation of prior period balances were adjusted to align with current year presentation.
	Reclassifications related to gains and losses on available for sale securities are included in Interest and other (expense) income, net. Refer to "Note 2: Financial Instruments" for the amount and location of reclassifications related to derivative instruments. Reclassifications of the defined benefit pension components are included in the computation of net periodic benefit cost. Refer to "Note 14: Retirement Benefit Plans."

Net_Income_Per_Share

Net Income Per Share	12 Months Ended
	Jan. 31, 2015
Earnings Per Share [Abstract]
Net Income Per Share	Net Income Per Share
	Basic net income per share is computed using the weighted average number of shares of common stock outstanding for the period, excluding stock options and restricted stock units. Diluted net income per share is based upon the weighted average number of shares of common stock outstanding for the period and potentially dilutive common shares, including the effect of stock options and restricted stock units under the treasury stock method. The following table sets forth the computation of the numerators and denominators used in the basic and diluted net income per share amounts:
		Fiscal Year Ended January 31,
		2015		2014		2013
	Numerator:
	Net income	$	81.8	$	228.8	$	247.4
	Denominator:
	Denominator for basic net income per share—weighted average shares	227.1		224		226.4
	Effect of dilutive securities	5.3		5.6		5.3
	Denominator for dilutive net income per share	232.4		229.6		231.7
	Basic net income per share	$	0.36	$	1.02	$	1.09
	Diluted net income per share	$	0.35	$	1	$	1.07
	The computation of diluted net income per share does not include shares that are anti-dilutive under the treasury stock method because their exercise prices are higher than the average market value of Autodesk’s stock during the fiscal year. For the fiscal years ended January 31, 2015, 2014, and 2013, 0.1 million, 5.4 million, and 9.6 million potentially anti-dilutive shares, respectively, were excluded from the computation of net income per share.

Segments

Segments	12 Months Ended
	Jan. 31, 2015
Segment Reporting [Abstract]
Segments	Segments
	Autodesk reports segment information based on the “management” approach. The management approach designates the internal reporting used by management for making decisions and assessing performance as the source of the Company’s reportable segments. Autodesk has four reportable segments: AEC, PSEB, MFG, and M&E. Autodesk has no material inter-segment revenue.
	The AEC, PSEB, and MFG segments derive revenue from the sale of licenses for software products and services to customers who design, build, manage, or own building, manufacturing, and infrastructure projects. Autodesk's M&E segment derives revenue from the sale of products to creative professionals, post-production facilities, and broadcasters for a variety of applications, including feature films, television programs, commercials, music and corporate videos, interactive game production, web design, and interactive web streaming.
	AEC software products help to improve the way building, civil infrastructure, process plant, and construction projects are designed, built, and managed. A broad portfolio of solutions enables greater efficiency, accuracy, and sustainability across the entire project lifecycle. Autodesk AEC solutions include advanced technology for BIM, AutoCAD-based design and documentation productivity software, sustainable design analysis applications, and collaborative project management solutions. BIM, an integrated process for building and infrastructure design, analysis, documentation, and construction, uses consistent, coordination information to improve communication and collaboration between the extended project team. AEC provides a comprehensive portfolio of BIM solutions that help customers deliver projects faster and more economically, while minimizing environmental impact. AEC’s revenue primarily includes revenue from the sales of licenses of Autodesk Building Design Suites, Autodesk Revit, Autodesk Infrastructure Design Suites, AutoCAD Civil 3D, and AutoCAD Map 3D.
	PSEB includes Autodesk’s design product, AutoCAD. Autodesk’s AutoCAD product is a platform product that underpins the Company’s design product offerings for the industries it serves. For example, AEC and MFG offer tailored versions of AutoCAD software for the industries they serve. Autodesk’s AutoCAD product also provides a platform for Autodesk’s developer partners to build custom solutions for a range of diverse design-oriented markets. PSEB's revenue primarily includes revenue from sales of AutoCAD and AutoCAD LT, the AutoCAD Design Suite and many other design products, including consumer design products, as well as from sales of licenses of other Autodesk's design products.
	MFG provides the manufacturers in automotive and transportation, industrial machinery, consumer products and building products with comprehensive digital prototyping solutions that bring together design data from all phases of the product development process to develop a single digital model created in Autodesk Inventor software. Autodesk’s solutions for digital prototyping enable a broad group of manufacturers to realize benefits with minimal disruption to existing workflows. MFG’s revenue primarily includes revenue from the sales of licenses of Autodesk Product Design Suites, Autodesk Inventor, AutoCAD Mechanical, and Autodesk Moldflow products.
	M&E consists of two product groups: Animation, including design visualization, and Creative Finishing. Animation products, such as Autodesk 3ds Max, Autodesk Maya, and the Autodesk Entertainment Creation Suites, provide tools for digital sculpting, modeling, animation, effects, rendering and compositing, for design visualization, visual effects, and games production. M&E products are also included in a number of PSEB, AEC, and MFG focused suites. Creative Finishing products, such as Autodesk Flame, Autodesk Smoke, and Autodesk Lustre, provide editing, finishing, and visual effects design and color grading.
	All of Autodesk’s reportable segments distribute their respective products primarily through authorized resellers and distributors and, to a lesser extent, through direct sales to end-users.
	The accounting policies of the reportable segments are the same as those described in Note 1, “Business and Summary of Significant Accounting Policies.” Autodesk evaluates each segment’s performance on the basis of gross profit. Autodesk currently does not separately accumulate and report asset information by segment, except for goodwill, which is disclosed in Note 1, “Business and Summary of Significant Accounting Policies.”
	Information concerning the operations of Autodesk’s reportable segments is as follows:
		Fiscal year ended January 31,
		2015			2014			2013
	Net revenue:
	Architecture, Engineering, and Construction (1)	$	872.6		$	730.6		$	701.1
	Platform Solutions and Emerging Business (1)	796.7			789.2			843
	Manufacturing	675.6			579.4			573.8
	Media and Entertainment (1)	167.3			174.7			194.3
		$	2,512.20		$	2,273.90		$	2,312.20
	Gross profit:
	Architecture, Engineering, and Construction (1)	$	785.8		$	663.8		$	642
	Platform Solutions and Emerging Business (1)	712.3			716.8			788.8
	Manufacturing	604			531.5			531.3
	Media and Entertainment	127.3			137.8			156.5
	Unallocated (2)	(59.3		)	(50.3		)	(44.9		)
		$	2,170.10		$	1,999.60		$	2,073.70
	Depreciation, amortization and accretion:
	Architecture, Engineering, and Construction	$	1.3		$	0.2		$	0.2
	Platform Solutions and Emerging Business	6.8			5.5			1.8
	Manufacturing	3			0.9			0.5
	Media and Entertainment	0.3			0.2			0.4
	Unallocated	134.5			122.1			124.9
		$	145.9		$	128.9		$	127.8
	_______________
	-1	Prior period segment revenue amounts have been updated to conform to the current period's presentation.
	-2	Unallocated amounts primarily relate to corporate expenses and other costs and expenses that are managed outside the reportable segments, including stock-based compensation expense.
	Information regarding Autodesk’s operations by geographic area is as follows:
		Fiscal year ended January 31,
		2015			2014			2013
	Net revenue:
	Americas
	U.S.	$	736.4		$	672.3		$	672.1
	Other Americas	161.6			146.6			164.1
	Total Americas	898			818.9			836.2
	Europe, Middle East, and Africa	980			851.8			868.5
	Asia Pacific
	Japan	269			274.5			278.3
	Other Asia Pacific	365.2			328.7			329.2
	Total Asia Pacific	634.2			603.2			607.5
	Total net revenue	$	2,512.20		$	2,273.90		$	2,312.20
	Information regarding Autodesk’s long-lived assets by geographic area is as follows:
		January 31,
		2015			2014
	Long-lived assets (1):
	Americas
	U.S.	$	108.8		$	89
	Other Americas	3.1			2.9
	Total Americas	111.9			91.9
	Europe, Middle East, and Africa	25			27.2
	Asia Pacific	22.3			11.2
	Total long-lived assets	$	159.2		$	130.3
	____________________
	-1	Long-lived assets exclude deferred tax assets, marketable securities, goodwill, and other intangible assets. Prior period amounts have been updated to conform to the current period's presentation.

Retirement_Benefit_Plans

Retirement Benefit Plans	12 Months Ended
	Jan. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Retirement Benefit Plans	Retirement Benefit Plans
	Pretax Savings Plan
	Autodesk has a 401(k) plan that covers nearly all U.S. employees. Eligible employees may contribute up to 50% of their pretax salary, subject to limitations mandated by the Internal Revenue Service. Autodesk makes voluntary cash contributions and matches a portion of employee contributions in cash. Autodesk’s contributions were $11.2 million in fiscal 2015, $8.1 million in fiscal 2014, and $7.9 million in fiscal 2013. Autodesk does not allow participants to invest in Autodesk common stock through the 401(k) plan.
	Defined Benefit Pension Plans
	Autodesk maintains certain defined benefit pension plans to employees primarily located in countries outside of the U.S, particularly the United Kingdom, Switzerland, and Japan. The Company deposits funds for specific plans, consistent with the requirements of local law, with insurance companies, third-party trustees, or into government-managed accounts, and accrues for the unfunded portion of the obligation, where material. Depending on the design of the plan, local customs, and market circumstances, the liabilities of a plan may exceed qualified plan assets.
	Benefit obligation and plan assets
	The changes in the projected benefit obligations and plan assets for the plans described above were as follows:
		Fiscal year ended January 31,
		2015				2014
	Beginning projected benefit obligation	$	62.2			$	61.5
	Service cost	4.6				5.4
	Interest cost	3.9				1.1
	Actuarial loss (gain)	18.8				(3.2		)
	Benefits paid	(7.5		)		(5.9		)
	Foreign currency exchange rate changes	(1.2		)		0.8
	Curtailments and settlements	(2.9		)		—
	Contributions by plan participants	5.9				2.5
	Business combinations	60.9				—
	Ending projected benefit obligation	$	144.7			$	62.2
	Beginning fair value of plan assets	$	40.7			$	37.5
	Actual return on plan assets	4.1				0.9
	Contributions paid by employer	4.9				5.2
	Contributions paid by plan participants	5.9				2.5
	Benefit payments	(7.5		)		(5.9		)
	Curtailments and settlements	(2.9		)		—
	Foreign currency exchange rate changes	(1.2		)		0.5
	Business combinations	60.2				—
	Ending fair value of plan assets	$	104.2			$	40.7
	Funded status	$	(40.5	)		$	(21.5	)
	Amounts included within the business combinations line above represent plan assets and liabilities assumed under the acquisition of Delcam.
	The amounts recognized on the consolidated balance sheets at the end of each period were as follows:
		Fiscal Year Ended January 31,
		2015				2014
	Other long-term liabilities	$	40.5			$	21.5
	Accumulated other comprehensive loss, before tax	26.6				8.7
	Net amount recognized	$	67.1			$	30.2
	On a worldwide basis, our defined benefit plans were 72% funded as of January 31, 2015. Funded status is not indicative of our ability to pay ongoing pension benefits or of Autodesk's obligation to fund retirement accounts.
	As of January 31, 2015, the aggregate accumulated benefit obligation was $124.3 million for the pension plans ($45.3 million as of January 31, 2014). Included in the aggregate data in the following tables are the amounts applicable to our defined benefit plans, with accumulated benefit obligations in excess of plan assets, as well as plans with projected benefit obligations in excess of plan assets. Amounts related to such plans at the end of each period were as follows:
			Fiscal Year Ended January 31,
			2015				2014
	Plans with accumulated benefit obligations in excess of plan assets:
	Accumulated benefit obligations		$	124			$	45.3
	Plan Assets		103.9				40.7
	Plans with projected benefit obligations in excess of plan assets:
	Projected benefit obligations		$	144.7			$	62.2
	Plan Assets		104.2				40.7
	Pension Plan Assets
	The investments of the plans are managed by insurance companies or third-party investment managers selected by Autodesk's Trustees, consistent with regulations or market practice of the country where the assets are invested. Investments managed by qualified insurance companies or third-party investment managers under standard contracts follow local regulations, and Autodesk is not actively involved in their investment strategies.
	Pension plan assets measured at fair value on a recurring basis consisted of the following investment categories at the end of each period as follows:
		Fiscal Year Ended January 31,
		2015													2014
		Level 1				Level 2				Level 3			Total		Total
	Investment fund	$	55.7			$	4.9			$	—		$	60.6	$	—
	Insurance contracts	—				43.5				—			43.5		40.2
	Total assets measured at fair value	55.7				48.4				—			104.1		40.2
	Cash	0.1				—				—			0.1		0.5
	Total pension plan assets at fair value	$	55.8			$	48.4			$	—		$	104.2	$	40.7
	The assets held in the investment fund in the preceding table are invested in a diversified growth fund actively managed by Russell Investments in association with Aon Hewitt. The objective of the fund is to generate capital appreciation on a long-term basis through a diversified portfolio of investments. The fund aims to deliver equity-like returns in the medium to long term with around two-thirds the volatility of equity markets. The fair value of the assets held in the investment fund classified as Level 1 are priced daily using observable inputs for identical assets. The fair value of the assets held in the investment fund classified as Level 2 are priced monthly at net asset value with quarterly redemption attributes.
	The insurance contracts in the preceding table represent the immediate cash surrender value of assets managed by qualified insurance companies. Autodesk does not have control over the target allocation or visibility of the investment strategies of those investments. Insurance contracts and investments held by insurance companies made up 42% of total plan assets as of January 31, 2015 (99% as of January 31, 2014).
	Estimated Future Benefit Payments
	Estimated benefit payments over the next 10 fiscal years are as follows:
		Pension Benefits
	2016	$	3.5
	2017	3.4
2018	3.5
2019	3.3
2020	3.1
2021-2025	17.5
Funding Expectations
Our expected required funding for the plans during fiscal 2016 is approximately $4.6 million.
Net Periodic Benefit Cost
The components of net periodic pension cost for the defined benefit pension plans for fiscal 2015, 2014, and 2013 are as follows:
	Fiscal Year Ended January 31,
	2015				2014				2013
Service cost for benefits earned during the period	$	4.6			$	5.4			$	4.5
Interest cost on projected benefit obligation	3.9				1.1				1.3
Expected return on plan assets	(4.6		)		(0.8		)		(0.8		)
Amortization of prior service credit	(0.1		)		(0.1		)		(0.1		)
Amortization of loss	0.6				1				0.7
Net periodic benefit cost	$	4.4			$	6.6			$	5.6
Amounts Recorded in OCI
The components of other comprehensive income for the defined benefit pension plans before taxes for fiscal 2015, 2014, and 2013 are as follows:
	Fiscal Year Ended January 31,
	2015				2014				2013
Net loss (gain) for period	$	18.4			$	(3.9	)		$	6.3
Amortization of prior service credit	0.1				0.1				0.1
Amortization of net loss	(0.6		)		(1.0		)		(0.7		)
Other comprehensive loss (income)	$	17.9			$	(4.8	)		$	5.7
Amounts Recorded in AOCI
The amounts recorded in accumulated other comprehensive income loss before taxes at the end of each period were as follows:
	Fiscal Year Ended January 31,
	2015				2014
Net prior service credit	$	(1.8	)		$	(1.9	)
Net actuarial loss	28.4				10.6
Accumulated other comprehensive loss, before tax	$	26.6			$	8.7
The estimated amounts that will be amortized from AOCI into net periodic benefit cost over the next fiscal year for the qualified defined benefit pension plan and other benefit plans are as follows:
	Pension Benefits
Amortization of prior service credit	$	0.1
Amortization of the net loss	(1.5		)
Total amortization	$	(1.4	)
Assumptions
Weighted average actuarial assumptions used to determine costs for the plans for each period were as follows:
	Fiscal Year Ended January 31,
	2015			2014			2013
Discount rate	3.3	%		2.3	%		1.8	%
Expected long-term rate of return on plan assets	3.9	%		1.9	%		2	%
Rate of compensation increase	2.2	%		2.2	%		2.1	%
The weighted-average expected long-term rate of return for the plan assets is 3.9%. The weighted-average expected long-term rate of return on plan assets is based on the interest rates guaranteed under the insurance contracts, and the expected rate of return appropriate for each category of assets weighted for the distribution within the diversified investment fund. The assumptions used for the plans are based upon customary rates and practices for the location of the plans. Factors such as asset class allocations, long-term rates of return (actual and expected), and results of periodic asset liability modeling studies are considered when constructing the long-term rate of return assumption for our pension plans.
Weighted average actuarial assumptions used to determine benefit obligations for the plans at the end of each period were as follows:
	Fiscal Year Ended January 31,
	2015			2014			2013
Discount rate	2.4	%		2.2	%		1.8	%
Rate of compensation increase	1.2	%		2.2	%		2	%
In selecting the appropriate discount rate for the plans, the Company uses country-specific information, adjusted to reflect the duration of the particular plan. The discount rate was based on highly rated long-term bond indexes and yield curves that match the duration of the plan’s benefit obligations.
Defined Contribution Plans
Autodesk also provides defined contribution plans in certain foreign countries where required by statute. Autodesk’s funding policy for foreign defined contribution plans is consistent with the local requirements in each country. Autodesk’s contributions to these plans were $23.5 million in fiscal 2015, $22.3 million in fiscal 2014, and $21.5 million in fiscal 2013.
Other Plans
In addition, Autodesk offers a non-qualified deferred compensation plan to certain key employees whereby they may defer a portion (or all) of their annual compensation until retirement or a different date specified by the employee in accordance with terms of the plan. See Note 6, “Deferred Compensation,” for further discussion.

Restructuring_Reserves

Restructuring Reserves	12 Months Ended
	Jan. 31, 2015
Restructuring and Related Activities [Abstract]
Restructuring Reserves	Restructuring Reserves
	During fiscal 2014, the Board of Directors of the Company approved a world-wide restructuring plan in order to re-balance staffing levels to better align them with the evolving needs of the business. The Company authorized plan included a reduction of approximately 85 positions and the consolidation of four leased facilities, with a total cost of approximately $15.0 million ("Fiscal 2014 Plan"). By July 31, 2014, the personnel and facilities related actions included in this restructuring plan were substantially complete.
	During fiscal 2013, the Board of Directors of the Company approved a world-wide restructuring plan in line with the Company's strategy, including its continuing shift to cloud and mobile computing ("Fiscal 2013 Plan"). The approved plan resulted in a reduction of approximately 500 positions and the consolidation of eight leased facilities, with an aggregate charge of $46.2 million to date. By January 31, 2014, the personnel and facilities related actions included in this restructuring plan were substantially complete.
	The following table sets forth the restructuring activities for the fiscal years ended January 31, 2015 and 2014:
		Balances, January 31, 2014		Additions		Payments			Adjustments (1)			Balances, January 31, 2015
	Fiscal 2013 Plan
	Employee termination costs	$	0.1	$	—	$	—		$	(0.1	)	$	—
	Lease termination and asset costs	0.2		0.3		(0.3		)				0.2
	Fiscal 2014 Plan
	Employee termination costs	3.5		2.5		(6.0		)	—			—
	Lease termination and asset costs	1.3		0.3		(0.5		)	0.3			1.4
	Total	$	5.1	$	3.1	$	(6.8	)	$	0.2		$	1.6
	Current portion (2)	$	4									$	0.7
	Non-current portion (2)	1.1										0.9
	Total	$	5.1									$	1.6
	____________________
	-1	Adjustments include the impact of foreign currency translation.
	-2	The current and non-current portions of the reserve are recorded in the Consolidated Balance Sheets under “Other accrued liabilities” and “Other liabilities,” respectively.
		Balances, January 31, 2013		Additions		Payments			Adjustments (1)			Balances, January 31, 2014
	Fiscal 2013 Plan
	Employee termination costs	$	4.5	$	0.8	$	(5.0	)	(0.2		)	$	0.1
	Lease termination and asset costs	2.8		1.5		(4.2		)	0.1			0.2
	Fiscal 2014 Plan
	Employee termination costs	—		9.4		(5.7		)	(0.2		)	3.5
	Lease termination and asset costs	—		1.1					0.2			1.3
	Total	$	7.3	$	12.8	$	(14.9	)	$	(0.1	)	$	5.1
	Current portion (2)	$	5.8									$	4
	Non-current portion (2)	1.5										1.1
	Total	$	7.3									$	5.1
	_______________
	-1	Adjustments include the impact of foreign currency translation.
	-2	The current and non-current portions of the reserve are recorded in the Consolidated Balance Sheets under “Other accrued liabilities” and “Other liabilities,” respectively.

Selected_Quarterly_Financial_I

Selected Quarterly Financial Information (Unaudited)	12 Months Ended
	Jan. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Information (Unaudited)	Selected Quarterly Financial Information (Unaudited)
	Summarized quarterly financial information for fiscal 2015 and 2014 is as follows:
	2015	1st quarter			2nd quarter			3rd quarter			4th quarter			Fiscal year
	Net revenue	$	592.5		$	637.1		$	618		$	664.6		$	2,512.20
	Gross profit	513.8			549.2			532			575.1			2,170.10
	Income from operations	42.2			49.9			14.6			14			120.7
	Provision for income taxes	(7.3		)	(11.6		)	(0.9		)	18.6			(1.2		)
	Net income	28.3			31.3			10.7			11.5			81.8
	Basic net income per share	$	0.12		$	0.14		$	0.05		$	0.05		$	0.36
	Diluted net income per share	$	0.12		$	0.13		$	0.05		$	0.05		$	0.35
	Income from operations includes the following items:
	Stock-based compensation expense	$	33.6		$	39.8		$	43.1		$	49.1		$	165.6
	Amortization of acquisition related intangibles	23.9			24.6			22.6			21.9			93
	Restructuring charges, net	2.3			0.8			—			—			3.1
	2014	1st quarter			2nd quarter			3rd quarter			4th quarter			Fiscal year
	Net revenue	$	570.4		$	561.7		$	555.2		$	586.6		$	2,273.90
	Gross profit	502.9			493.9			488.1			514.7			1,999.60
	Income from operations	81.4			83.6			68.1			51.7			284.8
	Provision for income taxes	(17.0		)	(20.1		)	(11.6		)	(2.4		)	(51.1		)
	Net income	55.6			61.7			57.6			53.9			228.8
	Basic net income per share	$	0.25		$	0.28		$	0.26		$	0.24		$	1.02
	Diluted net income per share	$	0.24		$	0.27		$	0.25		$	0.23		$	1
	Income from operations includes the following items:
	Stock-based compensation expense	$	33.5		$	31		$	31.6		$	36.1		$	132.2
	Amortization of acquisition related intangibles	21.6			20.3			18.2			20.6			80.7
	Restructuring charges, net	0.4			1.7			4.4			6.3			12.8

FINANCIAL_STATEMENT_SCHEDULE_I

FINANCIAL STATEMENT SCHEDULE II	12 Months Ended
	Jan. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Financial Statement Schedule II	FINANCIAL STATEMENT SCHEDULE II
	Description	Balance at		Additions		Deductions		Balance at
		Beginning		Charged to		and		End of Fiscal Year
		of Fiscal Year		Costs and		Write-Offs
				Expenses or
				Revenues
		(in millions)
	Fiscal Year Ended January 31, 2015
	Allowance for doubtful accounts	$	4.9	$	1.6	$	0.2	$	6.3
	Product returns reserves	4		17.4		18.8		2.6
	Partner Program reserves (1)	38.4		237.3		239.2		36.5
	Restructuring	5.6		3.2		7.2		1.6
	Fiscal Year Ended January 31, 2014
	Allowance for doubtful accounts	$	5.6	$	1.3	$	2	$	4.9
	Product returns reserves	4.9		23.1		24		4
	Partner Program reserves (1)	48.3		278.6		288.5		38.4
	Restructuring	8.9		12.8		16.1		5.6
	Fiscal Year Ended January 31, 2013
	Allowance for doubtful accounts	$	5.5	$	1.5	$	1.4	$	5.6
	Product returns reserves	5.8		25.8		26.7		4.9
	Partner Program reserves (1)	36.5		286.9		275.1		48.3
	Restructuring	2.4		45.1		38.6		8.9
	____________________
	-1	The partner program reserves balance impacts "Accounts receivable, net" and "Accounts payable" on the accompanying Consolidated Balance Sheets.

Business_and_Summary_of_Signif1

Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Jan. 31, 2015
Accounting Policies [Abstract]
Business	Business
	Autodesk, Inc. (“Autodesk” or the “Company”) is a world leading design software and services company, offering customers productive business solutions through powerful technology products and services. The Company serves customers in the architecture, engineering, and construction; manufacturing; and digital media, consumer, and entertainment industries. The Company’s sophisticated software products enable its customers to experience their ideas before they are real by allowing them to imagine, design, and create their ideas and to visualize, simulate, and analyze real-world performance early in the design process by creating digital prototypes. These capabilities allow Autodesk’s customers to foster innovation, optimize and improve their designs, help save time and money, improve quality, and collaborate with others. Autodesk software products are sold globally, both directly to customers and through a network of resellers and distributors.
Principles of Consolidation	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of Autodesk and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.
Reclassifications	Reclassifications
	During the first quarter of fiscal 2014, Autodesk combined maintenance revenue and cloud services offering-related revenue into one category named “Subscription.” As a result, revenue and cost of revenue related to cloud service offerings previously reflected in “License and other revenue” and “Cost of license and other revenue” were reclassified to “Subscription revenue” and “Cost of subscription revenue.”
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in Autodesk’s consolidated financial statements and notes thereto. These estimates are based on information available as of the date of the consolidated financial statements. On a regular basis, management evaluates these estimates and assumptions. Actual results may differ materially from these estimates.
	Examples of significant estimates and assumptions made by management involve the determination of the fair value of acquired assets and liabilities, goodwill, financial instruments, long-lived assets and other intangible assets, the realizability of deferred tax assets, and the fair value of stock awards. The Company also makes assumptions, judgments, and estimates in determining the accruals for uncertain tax positions, variable compensation, partner incentive programs, product returns reserves, allowances for doubtful accounts, asset retirement obligations, and legal contingencies.
Foreign Currency Translation and Transactions	Foreign Currency Translation and Transactions
	The assets and liabilities of Autodesk’s foreign subsidiaries are translated from their respective functional currencies into U.S. dollars at the rates in effect at the balance sheet date, and revenue and expense amounts are translated at exchange rates that approximate those rates in effect during the period in which the underlying transactions occur. Foreign currency translation adjustments are recorded as other comprehensive income (loss).
	Gains and losses realized from foreign currency transactions, those transactions denominated in currencies other than the foreign subsidiary’s functional currency, are included in interest and other income, net. Monetary assets and liabilities are remeasured using foreign currency exchange rates at the end of the period, and non-monetary assets are remeasured based on historical exchange rates.
Derivative Financial Instruments	Derivative Financial Instruments
	Under its risk management strategy, Autodesk uses derivative instruments to manage its short-term exposures to fluctuations in foreign currency exchange rates which exist as part of ongoing business operations. Autodesk’s general practice is to hedge a majority of transaction exposures denominated in euros, Japanese yen, Swiss francs, British pounds, Canadian dollars, and Australian dollars. These instruments have maturities between one to 12 months in the future. Autodesk does not enter into any derivative instruments for trading or speculative purposes.
	The bank counterparties in all contracts expose Autodesk to credit-related losses in the event of their nonperformance. However, to mitigate that risk, Autodesk only contracts with counterparties who meet the Company’s minimum requirements under its counterparty risk assessment process. Autodesk monitors ratings, credit spreads, and potential downgrades on at least a quarterly basis. Based on Autodesk’s on-going assessment of counterparty risk, the Company will adjust its exposure to various counterparties. Autodesk generally enters into master netting arrangements, which reduce credit risk by permitting net settlement of transactions with the same counterparty. However, Autodesk does not have any master netting arrangements in place with collateral features.
	Autodesk accounts for its derivative instruments as either assets or liabilities on the balance sheet and carries them at fair value. Gains and losses resulting from changes in fair value are accounted for depending on the use of the derivative and whether it is designated and qualifies for hedge accounting. Derivatives that do not qualify for hedge accounting are adjusted to fair value through earnings.
Cash and Cash Equivalents	Cash and Cash Equivalents
	Autodesk considers all highly liquid investments with insignificant interest rate risk and remaining maturities of three months or less at the date of purchase to be cash equivalents. Cash equivalents are recorded at cost, which approximates fair value.
Marketable Securities	Marketable Securities
	Marketable securities are stated at fair value. Marketable securities maturing within one year that are not restricted are classified as current assets.
	Autodesk determines the appropriate classification of its marketable securities at the time of purchase and re-evaluates such classification as of each balance sheet date. Autodesk carries all “available-for-sale securities” at fair value, with unrealized gains and losses, net of tax, reported in stockholders’ equity until disposition or maturity. Autodesk carries all “trading securities” at fair value, with unrealized gains and losses, recorded in “Interest and other income, net” in the Company’s Consolidated Statements of Operations.
	All of Autodesk’s marketable securities are subject to a periodic impairment review. The Company recognizes an impairment charge when a decline in the fair value of its investments below the cost basis is judged to be other-than-temporary. Autodesk considers various factors in determining whether to recognize an impairment charge, including the length of time and extent to which the fair value has been less than Autodesk’s cost basis, the financial condition and near-term prospects of the investee, and Autodesk’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in the market value.
Accounts Receivable, Net	Allowances for uncollectible trade receivables are based upon historical loss patterns, the number of days that billings are past due, and an evaluation of the potential risk of loss associated with problem accounts.
	The product returns reserves are based on historical experience of actual product returns, estimated channel inventory levels, the timing of new product introductions, channel sell-in for applicable markets, and other factors.
	As part of the indirect channel model, Autodesk has a partner incentive program that uses quarterly attainment of monetary rewards to motivate distributors and resellers to achieve mutually agreed upon business goals in a specified time period. A portion of these incentives reduce license and other revenue in the current period. The remainder, which relates to incentives on our Subscription Program, is recorded as a reduction to deferred revenue in the period the maintenance transaction is billed and subsequently recognized as a reduction to maintenance revenue over the contract period. These incentive balances do not require significant assumptions or judgments. The reserves associated with the partner incentive program are treated on the consolidated balance sheet as either contra account receivable (when due to distributors and direct resellers) or accounts payable (when due to indirect resellers).
Concentration of Credit Risk	Concentration of Credit Risk
	Autodesk places its cash, cash equivalents, and marketable securities in highly liquid instruments with, and in the custody of, diversified financial institutions globally with high credit ratings and limits the amounts invested with any one institution, type of security, and issuer.
Computer Equipment, Software, Furniture and Leasehold Improvements, Net	Computer Equipment, Software, Furniture, and Leasehold Improvements, Net
	Computer equipment, software, and furniture are depreciated using the straight-line method over the estimated useful lives of the assets, which range from three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the lease term.
	Costs incurred for computer software developed or obtained for internal use are capitalized for application development activities, if material, and immediately expensed for preliminary project activities and post-implementation activities. These capitalized costs are amortized over the software’s expected useful life, which is generally three years.
Software Development Costs	Software Development Costs
	Software development costs incurred prior to the establishment of technological feasibility are included in research and development expenses. Autodesk defines establishment of technological feasibility as the completion of a working model. Software development costs incurred subsequent to the establishment of technological feasibility through the period of general market availability of the products are capitalized and generally amortized over a three year period, if material.
Other Intangible Assets, Net	Other Intangible Assets, Net
	Other intangible assets include developed technologies, customer relationships, trade names, patents, user lists, and the related accumulated amortization. These assets are shown as “Developed technologies, net” and as part of “Other assets” in the Consolidated Balance Sheet. The majority of Autodesk’s other intangible assets are amortized to expense over the estimated economic life of the product, which ranges from one to ten years.
Goodwill	Goodwill
	Goodwill consists of the excess of the consideration transferred over the fair value of net assets acquired in business combinations. Autodesk assigns goodwill to the reporting unit associated with each business combination, and tests goodwill for impairment annually in its fourth fiscal quarter or more often if circumstances indicate a potential impairment. For purposes of the goodwill impairment test, a reporting unit is an operating segment or one level below.
	Autodesk has the option to perform an assessment of qualitative factors of impairment (“optional assessment”) prior to necessitating a two-step quantitative impairment test. Should the optional assessment be utilized for any given fiscal year, qualitative factors to consider include cost factors; financial performance; legal, regulatory, contractual, political, business, or other factors; entity specific factors; industry and market considerations, macroeconomic conditions, and other relevant events and factors affecting the reporting unit. If, after assessing the totality of events or circumstances, it is more likely than not that the fair value of the reporting unit is greater than its carrying value, then performing the two-step impairment test is unnecessary.
	Therefore, the two-step quantitative impairment test is necessary when either Autodesk does not utilize the optional assessment or, as a result of the optional assessment, it is not more likely than not that the fair value of the reporting unit is greater than its carrying value. In performing the two-step impairment test, Autodesk uses discounted cash flow models which include assumptions regarding projected cash flows. Variances in these assumptions could have a significant impact on Autodesk's conclusion as to whether goodwill is impaired, or the amount of any impairment charge. Impairment charges, if any, result from instances where the fair values of net assets associated with goodwill are less than their carrying values. As changes in business conditions and assumptions occur, Autodesk may be required to record impairment charges. The process of evaluating the potential impairment of goodwill is subjective and requires significant judgment at many points during the analysis. The value of Autodesk’s goodwill could also be impacted by future adverse changes such as: (i) declines in Autodesk’s actual financial results, (ii) a sustained decline in Autodesk’s market capitalization, (iii) significant slowdown in the worldwide economy or the industries Autodesk serves, or (iv) changes in Autodesk’s business strategy or internal financial forecast results.
	For the fiscal 2015 annual goodwill impairment testing, Autodesk had five reporting units: PSEB, Manufacturing ("MFG"), Architecture, Engineering, and Construction ("AEC"), Media and Entertainment ("M&E"), and Delcam.
	For the annual impairment assessment in fiscal 2015, Autodesk utilized the optional assessment for Delcam. Based on a review of the qualitative factors described above, we determined that for our Delcam reporting unit, it was more likely than not that the fair value of the reporting unit exceeded the carrying value. As a result, we concluded that performing the two-step impairment test was not necessary for Delcam.
	For each of the remaining four reporting units, Autodesk did not utilize the optional assessment but rather performed the quantitative two-step impairment test. In performing the quantitative two-step test, Autodesk used a discounted cash flow model which included assumptions regarding projected cash flows.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
	At least annually or more frequently as circumstances dictate, Autodesk reviews its long-lived assets for impairment whenever impairment indicators exist.  Autodesk continually monitors events and changes in circumstances that could indicate the carrying amounts of its long-lived assets may not be recoverable. When such events or changes in circumstances occur, Autodesk assesses recoverability of these assets.  Recoverability is measured by comparison of the carrying amounts of the assets to the future undiscounted cash flows the assets are expected to generate.  If the long-lived assets are considered to be impaired, the impairment to be recognized is equal to the amount by which the carrying value of the assets exceeds its fair market value. Autodesk did not recognize any impairment of long-lived assets during the fiscal years ended January 31, 2015, 2014, and 2013, respectively.
	In addition to the recoverability assessments, Autodesk routinely reviews the remaining estimated useful lives of its long-lived assets. Any reduction in the useful life assumption will result in increased depreciation and amortization expense in the quarter when such determinations are made, as well as in subsequent quarters.
Deferred Tax Assets	Deferred Tax Assets
	Deferred tax assets arise primarily from tax credits, net operating losses, and timing differences for reserves, accrued liabilities, stock options, deferred revenue, purchased technologies, and capitalized intangibles, partially offset by the establishment of U.S. deferred tax liabilities on unremitted earnings from certain foreign subsidiaries, and valuation allowances against U.S. and foreign deferred tax assets. We perform a quarterly assessment of the recoverability of these net deferred tax assets and believe that we will generate sufficient future taxable income in appropriate tax jurisdictions to realize the net deferred tax assets. They are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. Valuation allowances are established when necessary to reduce gross deferred tax assets to the amount “more likely than not” expected to be realized.
Revenue Recognition	Revenue Recognition
	Autodesk recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable, and collection is probable.
	For multiple element arrangements containing only software and software-related elements, Autodesk allocates the sales price among each of the deliverables using the residual method, under which revenue is allocated to undelivered elements based on their vendor-specific objective evidence (“VSOE”) of fair value. VSOE is the price charged when an element is sold separately or a price set by management with the relevant authority. If Autodesk does not have VSOE of an undelivered element, revenue recognition is deferred on the entire sales arrangement until all elements for which Autodesk does not have VSOE are delivered. If Autodesk does not have VSOE for undelivered maintenance or services, the revenue for the arrangement is recognized over the longest contractual service period in the arrangement. Revenue recognition for significant lines of business is discussed further below.
	For multiple element arrangements involving non-software elements, including cloud subscription services, our revenue recognition policy is based upon the accounting guidance contained in ASC 605, Revenue Recognition. For these arrangements, Autodesk first allocates the total arrangement consideration based on the relative selling prices of the software group of elements as a whole and the non-software elements. Autodesk then further allocates consideration within the software group to the respective elements within that group using the residual method as described above. Autodesk exercises judgment and uses estimates in connection with the determination of the amount of revenue to be recognized in each accounting period.
	Autodesk allocates the total arrangement consideration among the various elements based on a selling price hierarchy. The selling price for a deliverable is based on its VSOE if available, third-party evidence ("TPE") if VSOE is not available, or the best estimated selling price ("BESP") if neither VSOE nor TPE is available. BESP represents the price at which Autodesk would transact for the deliverable if it were sold regularly on a standalone basis. To establish BESP for those elements for which neither VSOE nor TPE are available, Autodesk performs a quantitative analysis of pricing data points for historical standalone transactions involving such elements for a twelve-month period. As part of this analysis, Autodesk monitors and evaluates the BESP against actual pricing to ensure that it continues to represent a reasonable estimate of the standalone selling price, considering several other external and internal factors including, but not limited to, pricing and discounting practices, contractually stated prices, the geographies in which Autodesk offers products and services, and the type of customer (i.e. distributor, value-added reseller, and direct end user, among others). Autodesk analyzes BESP at least annually or on a more frequent basis if a significant change in our business necessitates a more timely analysis, or if significant selling price variances are experienced.
	Autodesk’s assessment of likelihood of collection is also a critical element in determining the timing of revenue recognition. If collection is not probable, the revenue will be deferred until the earlier of when collection is deemed probable or cash is received.
	License and other revenue are comprised of two components: (1) all forms of product license revenue and (2) other revenue.
	(1) All Forms of Product License Revenue
	Product license revenue includes: software license revenue from the sale of new seat licenses and upgrades and product revenue for Creative Finishing.
	(2) Other Revenue
	Other revenue includes revenue from consulting, training, Autodesk Developers Network, and Creative Finishing customer support, and is recognized over time, as the services are performed.
	Autodesk's Subscription revenue consists of two components: maintenance revenue for our software products and revenue for our cloud service offerings, including Autodesk 360. Autodesk's maintenance program provides our commercial and educational customers of perpetual products with a cost effective and predictable budgetary option to obtain the productivity benefits of our new releases and enhancements when and if released during the term of their contracts. Under Autodesk's maintenance program, customers are eligible to receive unspecified upgrades when and if available, downloadable training courses, and online support. Autodesk recognizes maintenance revenue ratably over the term of the maintenance agreement, which is generally between one and three years but can occasionally be as long as five years. Revenue for Autodesk's cloud service offerings is recognized ratably over the contract term commencing with the date Autodesk's service is made available to customers and all other revenue recognition criteria have been satisfied.
Taxes Collected from Customers	Taxes Collected from Customers
	Autodesk nets taxes collected from customers against those remitted to government authorities in the consolidated financial statements. Accordingly, taxes collected from customers are not reported as revenue.
Shipping and Handling Cost	Shipping and Handling Costs
	Shipping and handling costs are included in cost of revenue for all periods presented.
Stock-Based Compensation Expense	Autodesk estimates expected volatility for stock-based awards based on the average of the following two measures. The first is a measure of historical volatility in the trading market for the Company’s common stock, and the second is the implied volatility of traded forward call options to purchase shares of the Company’s common stock. The expected volatility for PSUs subject to market conditions includes the expected volatility of Autodesk's peer companies within the S&P Computer Software Select Index.
	Autodesk estimates the expected life of stock-based awards using both exercise behavior and post-vesting termination behavior as well as consideration of outstanding options.
	Autodesk did not pay cash dividends in fiscal 2015, 2014, or 2013 and does not anticipate paying any cash dividends in the foreseeable future. Consequently, an expected dividend yield of zero is used in the Black-Scholes-Merton option pricing model and the Monte Carlo simulation model.
	The risk-free interest rate used in the BSM option pricing model and the Monte Carlo simulation model for stock-based awards is the historical yield on U.S. Treasury securities with equivalent remaining lives.
	Autodesk recognizes expense only for the stock-based awards that are ultimately expected to vest. Therefore, Autodesk has developed an estimate of the number of awards expected to cancel prior to vesting (“forfeiture rate”). The forfeiture rate is estimated based on historical pre-vest cancellation experience and is applied to all stock-based awards. The Company estimates forfeitures at the time of grant and revises those estimates in subsequent periods if actual forfeitures differ from those estimates.
	Autodesk determines the grant-date fair value of its share-based payment awards using a Black-Scholes Merton Option ("BSM") pricing model or the quoted stock price on the date of grant, unless the awards are subject to market conditions, in which case Autodesk uses a binomial-lattice model (e.g., Monte Carlo simulation model). The Monte Carlo simulation model utilizes multiple input variables to estimate the probability that market conditions will be achieved.
Advertising Expenses	Advertising Expenses
	Advertising costs are expensed as incurred.
Net Income Per Share	Net Income Per Share
	Basic net income per share is computed based on the weighted average number of shares of common stock outstanding for the period, excluding stock options and restricted stock units. Diluted net income per share is computed based upon the weighted average shares of common shares outstanding for the period and potentially dilutive common shares, including the effect of stock options and restricted stock units under the treasury stock method.
Defined Benefit Pension Plans	Defined Benefit Pension Plans
	The funded status of Autodesk's defined benefit pension plans is recognized in the Consolidated Balance Sheets. The funded status is measured as the difference between the fair value of plan assets and the projected benefit obligation for the fiscal years presented. The projected benefit obligation represents the actuarial present value of benefits expected to be paid upon retirement based on employee services already rendered and estimated future compensation levels. The fair value of plan assets represents the current market value of Autodesk's cumulative company and participant contributions made to the various plans in effect.
	Net periodic benefit cost is recorded in the Consolidated Statements of Operations and includes service cost, interest cost, expected return on plan assets, amortization of prior service costs, and gains or losses previously recognized as a component of other comprehensive income. Certain events, such as changes in the employee base, plan amendments, and changes in actuarial assumptions may result in a change in the defined benefit obligation and the corresponding change to other comprehensive income.
	Gains and losses and prior service costs not recognized as a component of net periodic benefit cost in the Consolidated Statements of Operations as they arise are recognized as a component of other comprehensive income in the Consolidated Statements of Comprehensive Income. Those gains and losses and prior service costs are subsequently amortized as a component of net periodic benefit cost over the average remaining service lives of the plan participants using a corridor approach to determine the portion of gain or loss subject to amortization.
	The measurement of projected benefit obligations and net periodic benefit cost is based on estimates and assumptions that reflect the terms of the plans and use participant-specific information such as compensation, age and years of services, as well as certain assumptions, including estimates of discount rates, expected return of plan assets, rate of compensation increases, interest rates, and mortality rates.
Accounting Standards in Fiscal 2015	Accounting Standards in Fiscal 2015
	With the exception of those discussed below, there have been no recent changes in accounting pronouncements issued by the FASB or adopted by the Company during the fiscal year ended January 31, 2015, that are of significance, or potential significance, to the Company.
	Accounting Standards Adopted
	Effective February 1, 2014, Autodesk prospectively adopted FASB's Accounting Standards Update (“ASU”) 2013-11 regarding ASC Topic 740 “Income Tax.” This ASU clarifies the guidance on the presentation of an unrecognized tax benefit, or a portion of an unrecognized tax benefit, in the consolidated financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The adoption of this ASU resulted in an $81.9M reduction of both our long term taxes payable and long-term deferred tax assets as of January 31, 2015.
	Recently Issued Accounting Standards
	On May 28, 2014, the FASB issued ASU 2014-09 regarding ASC Topic 606 “Revenue from Contracts with Customers.” This ASU provides principles for recognizing revenue for the transfer of promised goods or services to customers with the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU will be effective for Autodesk’s fiscal year beginning February 1, 2017. Early adoption is not permitted. Autodesk is currently evaluating the accounting, transition, and disclosure requirements of the standard and cannot currently estimate the financial statement impact of adoption.

Business_and_Summary_of_Signif2

Business and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Jan. 31, 2015
Accounting Policies [Abstract]
Schedule of Reclassification Amount	These revenues and expenses have been reclassified in the Consolidated Statements of Operations for fiscal year 2013 to conform to the current period presentation as follows:
			Fiscal year ended January 31,
			2013
	Reclassifications within revenue:
	Decrease to License and other revenue		$	(26.5	)
	Increase to Subscription revenue		26.5
	Reclassifications within cost of revenue:
	Decrease to Cost of license and other revenue		$	(32.1	)
	Increase to Cost of subscription revenue		32.1
	During the second quarter of fiscal 2015, Autodesk elected to present amortization of purchased customer relationships, trade names, patents, and user lists as a separate line item within operating expenses. As a result, amortization previously reflected in “General and Administrative” expense was reclassified to “Amortization of Purchased Intangibles" within Operating Expenses. These expenses have been reclassified in the Consolidated Statements of Operations for fiscal years 2014 and 2013 to conform to the current period presentation as follows:
		Fiscal year ended January 31,
		2014				2013
	Reclassifications within operating expenses:
	(Decrease) to general and administrative	$	(36.5	)		$	(42.1	)
	Increase to amortization of purchased intangibles	36.5				42.1
Schedule of Accounts, Notes, Loans and Financing Receivable	Accounts receivable, net, consisted of the following as of January 31:
		2015				2014
	Trade accounts receivable	$	495.4			$	464.6
	Less: Allowance for doubtful accounts	(6.3		)		(4.9		)
	Product returns reserve	(2.6		)		(4.0		)
	Partner programs and other obligations	(27.6		)		(32.0		)
	Accounts receivable, net	$	458.9			$	423.7
Concentration Risk Disclosure	Geographical concentrations of consolidated cash, cash equivalents, and marketable securities held by Autodesk as of January 31:
		2015			2014
	United States	19	%		25	%
	Other Americas	1	%		1	%
	Europe, Middle East, and Africa (“EMEA”)	56	%		57	%
	Asia Pacific (“APAC”)	24	%		17	%
Property, Plant and Equipment	Computer equipment, software, furniture, leasehold improvements and the related accumulated depreciation at January 31 were as follows:
		2015				2014
	Computer hardware, at cost	$	194			$	163
	Computer software, at cost	84.9				80.9
	Leasehold improvements, land, and buildings, at cost	176.3				163.7
	Furniture and equipment, at cost	53				51.7
	Computer software, hardware, leasehold improvements, furniture, and equipment, at cost	508.2				459.3
	Less: Accumulated depreciation	(349.0		)		(329.0		)
	Computer software, hardware, leasehold improvements, furniture, and equipment, net	$	159.2			$	130.3
Schedule of Finite-Lived Intangible Assets by Major Class	Other intangible assets and related accumulated amortization at January 31 were as follows:
		2015				2014
	Developed technologies, at cost	$	538.4			$	462.4
	Customer relationships, trade names, patents, and user lists, at cost (1)	348.9				268.1
		887.3				730.5
	Less: Accumulated amortization	(715.4		)		(626.2		)
	Other intangible assets, net	$	171.9			$	104.3
	_______________
	-1	Included as a net balance in “Other assets” in the Consolidated Balance Sheet. Customer relationships and trade names include the effects of foreign currency translation.
Schedule of Expected Amortization Expense	Expected future amortization expense for developed technologies, customer relationships, trade names, patents, and user lists for each of the fiscal years ended thereafter is as follows:
		Fiscal Year ended January 31,
	2016	$	73.2
	2017	49.7
	2018	24
	2019	15.5
	2020	5.3
	Thereafter	4.2
	Total	$	171.9
Schedule of Goodwill	The change in the carrying amount of goodwill during the fiscal year ended January 31, 2015 is as follows:
		Platform Solutions and Emerging Business				Architecture, Engineering, and Construction				Manufacturing				Media and Entertainment			Delcam			Total
	Balance as of January 31, 2014
	Goodwill	$	142.3			$	415.2			$	411.6			$	190		$	—		$	1,159.10
	Accumulated impairment losses	—				—				—				(149.2		)	—			(149.2		)
		142.3				415.2				411.6				40.8			—			1,009.90
	Delcam plc	—				—				—				—			196.1			196.1
	Within Technologies Limited	80.6				—				—				—						80.6
	Shotgun Software Inc.	—				—				—				43.2						43.2
	Goodwill acquired from other acquisitions	117.8				28.1				20.1				15.3						181.3
	Effect of foreign currency translation, purchase accounting adjustments, and other	(13.2		)		(16.3		)		(9.0		)		(3.3		)	(13.1		)	(54.9		)
	Balance as of January 31, 2015
	Goodwill	327.5				427				422.7				245.2			183			1,605.40
	Accumulated impairment losses	—				—				—				(149.2		)	—			(149.2		)
		$	327.5			$	427			$	422.7			$	96		$	183		$	1,456.20
	The change in the carrying amount of goodwill during the fiscal year ended January 31, 2014 is as follows:
		Platform Solutions and Emerging Business				Architecture, Engineering, and Construction				Manufacturing				Media and Entertainment			Total
	Balance as of January 31, 2013
	Goodwill	$	129.5			$	310.3			$	389.9			$	191		$	1,020.70
	Accumulated impairment losses	—				—				—				(149.2		)	(149.2		)
		129.5				310.3				389.9				41.8			871.5
	Graitec SA	—				73.4				—				—			73.4
	Goodwill acquired from other acquisitions	12.8				32				22.2				—			67
	Effect of foreign currency translation, purchase accounting adjustments, and other	—				(0.5		)		(0.5		)		(1.0		)	(2.0		)
	Balance as of January 31, 2014
	Goodwill	142.3				415.2				411.6				190			1,159.10
	Accumulated impairment losses	—				—				—				(149.2		)	(149.2		)
		$	142.3			$	415.2			$	411.6			$	40.8		$	1,009.90
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	The following table summarizes stock-based compensation expense for fiscal 2015, 2014, and 2013, respectively, as follows:
		Fiscal Year Ended January 31,
		2015				2014				2013
	Cost of license and other revenue	$	4.6			$	3.8			$	3.7
	Cost of subscription	4.3				2.2				1.5
	Marketing and sales	72.4				58.6				64.3
	Research and development	56				43.7				61.8
	General and administrative	28.3				23.9				25
	Stock-based compensation expense related to stock awards and ESP Plan purchases	165.6				132.2				156.3
	Tax benefit	(45.2		)		(36.4		)		(35.5		)
	Stock-based compensation expense related to stock awards and ESP Plan purchases, net	$	120.4			$	95.8			$	120.8
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award	Autodesk uses the following assumptions to estimate the fair value of stock-based awards:
			Fiscal Year Ended				Fiscal Year Ended				Fiscal Year Ended
			January 31, 2015				January 31, 2014				January 31, 2013
			Performance Stock Unit (1)		ESP Plan		Performance Stock Unit (1)		ESP Plan		Stock Option (2)		ESP Plan
	Range of expected volatilities		30%		29 - 33%		34%		27 - 36%		41 - 45%		41 - 44%
	Range of expected lives (in years)		N/A		0.5 - 2.0		N/A		0.5 - 2.0		3.6 - 4.6		0.5 - 2.0
	Expected dividends		—%		—%		—%		—%		—%		—%
	Range of risk-free interest rates		0.10%		0.0 - 0.6%		0.10%		0.1 - 0.4%		0.5 - 0.8%		0.1 - 0.3%
	_______________
	-1	Autodesk did not grant PSUs in fiscal 2013 that were subject to market conditions.
	-2	Autodesk did not grant stock options in fiscal 2015 or 2014.

Financial_Instruments_Tables

Financial Instruments (Tables)	12 Months Ended
	Jan. 31, 2015																							Jan. 31, 2014
Investments, All Other Investments [Abstract]
Cost and Fair Value of Financial Instruments Disclosure	The following tables summarize the Company's financial instruments' amortized cost, gross unrealized gains, gross unrealized losses, and fair value by significant investment category as of January 31, 2015 and 2014.
																											January 31, 2014
				January 31, 2015																							Amortized Cost		Gross unrealized gains		Gross unrealized losses			Fair Value		Level 1		Level 2		Level 3
				Amortized Cost				Gross unrealized gains				Gross unrealized losses				Fair Value		Level 1		Level 2		Level 3		Cash equivalents (1):
	Cash equivalents (1):																								Certificates of deposit and time deposits		$	280.7	$	—	$	—		$	280.7	$	30.4	$	250.3	$	—
		Corporate debt securities		$	258.6			$	—			$	—			$	258.6	$	258.6	$	—	$	—
																									Municipal securities		2		—		—			2		2		—		—
		Custody cash deposit		141.5				—				—				141.5		141.5		—		—
																									Commercial paper		280.5		—		—			280.5		—		280.5		—
		Commercial paper		161				—				—				161		—		161		—
																									Money market funds		262.8		—		—			262.8		—		262.8		—
		Corporate bond		11.5				—				—				11.5		11.5		—		—
																								Marketable securities:
		Money market funds		127.3				—				—				127.3		—		127.3		—			Short-term available for sale
																										Commercial paper and corporate debt securities	261		—		—			261		95.4		165.6		—
	Marketable securities:
		Short-term available for sale																								Time deposits	37.1		—		—			37.1		—		37.1		—
			Agency bond	37.9				—				—				37.9		37.9		—		—
																										U.S. government agency securities	11.3		—		—			11.3		11.3		—		—
			Corporate debt securities	148				0.1				(0.1		)		148		148		—		—
																										Agency bond	42.7		—		—			42.7		42.7		—		—
			Municipal bond	29.2				0.1				—				29.3		29.3		—		—
																										Municipal securities	11.7		—		—			11.7		11.7		—		—
			Certificate of deposit	101.9				—				—				101.9		101.9		—		—
																										Other (2)	11.4		—		—			11.4		11.4		—		—
			Commercial paper	258.4				—				—				258.4		—		258.4		—
																									Short-term trading securities
		Short-term trading securities																								Mutual funds	35.6		3.3		—			38.9		38.9		—		—
			Mutual funds	36.9				3.4				—				40.3		40.3		—		—
																									Long-term available for sale
		Long-term available for sale																								Corporate debt securities	179.7		0.7		(0.1		)	180.3		180.3		—		—
			Agency bond	50.6				0.2				—				50.8		50.8		—		—
																										Agency bond	43.3		0.1		—			43.4		43.4		—		—
			Corporate debt securities	199.4				0.6				(0.2		)		199.8		199.8		—		—
																										U.S. government agency securities	9.8		—		—			9.8		9.8		—		—
			Municipal securities	13.3				0.1				—				13.4		13.4		—		—
																										Municipal securities	43.5		0.3		—			43.8		43.8		—		—
			U.S. government agency securities	8.9				0.1				—				9		9		—		—
																								Convertible Debt Securities (3)			21.4		3.2		(4.4		)	20.2		—		—		20.2
	Convertible debt securities (2)			4.7				2.5				(2.1		)		5.1		—		—		5.1
																								Derivative contracts (4)			10.8		14.8		(6.0		)	19.6		—		10.5		9.1
	Derivative contracts (3)			3.5				19.5				(7.0		)		16		—		15.1		0.9
																										Total	$	1,545.30	$	22.4	$	(10.5	)	$	1,557.20	$	521.1	$	1,006.80	$	29.3
			Total	$	1,592.60			$	26.6			$	(9.4	)		$	1,609.80	$	1,042.00	$	561.8	$	6
																								____________________
	____________________
																								-1	Included in “Cash and cash equivalents” in the accompanying Consolidated Balance Sheets.
	-1	Included in “Cash and cash equivalents” in the accompanying Consolidated Balance Sheets.
																								-2	Consists of agency discount notes, U.S. treasury bills, and other short-term securities.
	-2	Considered "available for sale" and included in "Other assets" in the accompanying Consolidated Balance Sheets.
																								-3	Considered "available for sale" securities and included in "Other assets" in the accompanying Consolidated Balance Sheets.
	-3	Included in “Prepaid expenses and other current assets,” "Other assets," or “Other accrued liabilities” in the accompanying Consolidated Balance Sheets.
																								-4	Included in “Prepaid expenses and other current assets,” "Other assets," or “Other accrued liabilities” in the accompanying Consolidated Balance Sheets.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	A reconciliation of the change in Autodesk’s Level 3 items for the fiscal years ended January 31, 2015 and 2014 was as follows:
		Fair Value Measurements Using
		Significant Unobservable Inputs
		(Level 3)
			Derivative Contracts				Convertible Debt Securities				Taxable Auction-Rate Securities				Total
	Balance at January 31, 2013		$	10.7			$	17.5			$	4.2			$	32.4
	Purchases		1.3				3.1				—				4.4
	Settlements		—				—				(4.0		)		(4.0		)
	Losses included in earnings (1)		(2.9		)		—				(0.2		)		(3.1		)
	Losses included in OCI (1)		—				(0.4		)		—				(0.4		)
	Balance at January 31, 2014		9.1				20.2				—				29.3
	Purchases		0.1				0.6				—				0.7
	Settlements		(0.8		)		(3.0		)		—				(3.8		)
	Losses included in earnings		(7.5		)		(13.3		)		—				(20.8		)
	Gains included in OCI		—				0.6				—				0.6
	Balance at January 31, 2015		$	0.9			$	5.1			$	—			$	6
	(1) For comparability, the presentation of prior period balances were adjusted to align with current year presentation.
Available-for-sale Securities	The following table summarizes the estimated fair value of Autodesk's “available-for-sale securities” classified by the contractual maturity date of the security:
		January 31, 2015
		Cost				Fair Value
	Due in 1 year	$	575.4			$	575.5
	Due in 1 year through 5 years	276.9				278.1
	Total	$	852.3			$	853.6
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The fair value of derivative instruments in Autodesk’s Consolidated Balance Sheets were as follows as of January 31, 2015 and January 31, 2014:
		Balance Sheet Location		Fair Value at
				January 31, 2015				January 31, 2014
	Derivative Assets
	Foreign currency contracts designated as cash flow hedges	Prepaid expenses and other current assets (1)		$	20.4			$	4.4
	Derivatives not designated as hedging instruments	Prepaid expenses and other current assets and Other assets		0.9				16.9
	Total derivative assets			$	21.3			$	21.3
	Derivative Liabilities
	Foreign currency contracts designated as cash flow hedges	Other accrued liabilities (2)		$	5.4			$	1.7
	Total derivative liabilities			$	5.4			$	1.7
	_______________
	-1	Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $23.8 million and $5.9 million at January 31, 2015 and January 31, 2014, respectively.
	-2	Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $8.7 million and $3.2 million at January 31, 2015 and January 31, 2014, respectively.
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	The effects of derivatives designated as hedging instruments on Autodesk’s Consolidated Statements of Operations were as follows for the fiscal years ended January 31, 2015, 2014, and 2013, respectively (amounts presented include any income tax effects):
		Foreign Currency Contracts
		Fiscal Year Ended January 31,
		2015				2014				2013
	Amount of gain recognized in accumulated other comprehensive income on derivatives (effective portion)	$	46.4			$	12.2			$	5.1
	Amount and location of gain reclassified from accumulated other comprehensive income into income (effective portion)
	Net revenue	$	10.5			$	13.1			$	16
	Operating expenses	(3.5		)		(1.6		)		(4.6		)
	Total	$	7			$	11.5			$	11.4
	Amount and location of gain (loss) recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing)
	Interest and other (expense) income, net	$	0.9			$	(0.1	)		$	(0.2	)
	The effects of derivatives not designated as hedging instruments on Autodesk’s Consolidated Statements of Operations were as follows for the fiscal years ended January 31, 2015, 2014, and 2013, respectively (amounts presented include any income tax effects):
		Foreign Exchange Contracts
		Fiscal Year Ended January 31,
		2015				2014				2013
	Amount and location of (loss) gain recognized in income on derivative
	Interest and other (expense) income, net	$	(25.5	)		$	12.8			$	1.5

Employee_and_Director_Stock_Pl1

Employee and Director Stock Plans (Tables)	12 Months Ended
	Jan. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	A summary of stock option activity for the fiscal year ended January 31, 2015 is as follows:
		Number of Shares		Weighted average exercise price per share				Weighted average remaining contractual term		Aggregate Intrinsic Value (3)
		(in millions)						(in years)		(in millions)
	Options outstanding at January 31, 2014	5.9		$	33.54
	Granted (1)	—		—
	Exercised	(3.2	)	32.76
	Canceled/Forfeited	—		—
	Options outstanding at January 31, 2015	2.7		$	34.46			4.2		$	53.1
	Options vested and exercisable at January 31, 2015	2.5		$	33.72			3.9		$	49.9
	Options vested and exercisable as of January 31, 2015 and expected to vest thereafter (2)	2.7		$	34.46			4.2		$	53.1
	Options available for grant at January 31, 2015	14.3
	_______________
	-1	Autodesk did not grant stock options in the twelve months ended January 31, 2015.
	-2	Options expected to vest reflect an estimated forfeiture rate.
	-3	Represents the total pre-tax intrinsic value, based on Autodesk’s closing stock price of $54.01 per share as of January 31, 2015, which would have been received by the option holders had all option holders exercised their options as of that date.
Intrinsic Value of Options Exercised and Weighted Average Grant Date Fair Value of Stock Options Granted	The following table summarizes information about the pre-tax intrinsic value of options exercised and the weighted average grant date fair value per share of options granted during the fiscal years ended January 31, 2015, 2014, and 2013:
		Fiscal year ended January 31,
		2015			2014				2013
	Intrinsic value of options exercised (1)	$	67.6		$	149			$	90.9
	Weighted average grant date fair value per share of stock options granted (2)	$	—		$	—			$	13.4
	——————
	-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 Black-Scholes Merton ("BSM") option pricing model. For the twelve months ended January 31, 2015 and 2014, Autodesk did not grant stock options.
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range	The following table summarizes information about options vested and exercisable, and outstanding at January 31, 2015:
		Options Vested and Exercisable										Options Outstanding
		Number of Shares (in millions)		Weighted average contractual life (in years)		Weighted average exercise price per share				Aggregate intrinsic value(1) (in millions)		Number of Shares (in millions)	Weighted average contractual life (in years)	Weighted average exercise price per share		Aggregate intrinsic value(1) (in millions)
	Range of per-share exercise prices:
	$12.31 - $29.49	0.9				$	23.76					0.9		$	23.83
	$29.50 - $41.62	1.2				38.73						1.3		38.85
	$42.39 - $43.81	0.4				43.8						0.5		43.79
		2.5		3.9		$	33.72			$	49.9	2.7	4.2	$	34.46	$	53.1
	____________________
	-1	Represents the total pre-tax intrinsic value, based on Autodesk’s closing stock price of $54.01 per share as of January 31, 2015, which would have been received by the option holders had all option holders exercised their options as of that date.
Restricted Share Activity Disclosure	A summary of restricted stock unit activity for the fiscal year ended January 31, 2015 is as follows:
		Unreleased Restricted Stock Units		Weighted average grant date fair value
		(in thousands)
	Unreleased restricted stock units at January 31, 2014	6,515.60		$	39.15
	Granted	4,481.80		54.17
	Vested	(2,675.6	)	37.36
	Canceled/Forfeited	(445.8	)	41.43
	Performance Adjustment (1)	(74.7	)	42.23
	Unreleased restricted stock units at January 31, 2015	7,801.30		$	48.46
	_______________
	-1	Based on Autodesk's financial results for the performance period, the fiscal 2014 and 2013 performance stock units were earned at 65.8% and 92.3% of the target award, respectively. The vesting of the performance stock units is subject to the holders satisfying the remaining service condition of the awards.
Employee and Director Stock Options Outstanding	The following table summarizes the number of outstanding options granted to employees and directors, as well as the number of securities remaining available for future issuance under these plans as of January 31, 2015:
		(a)		(b)				(c)
	Plan category	Number of securities to be issued upon exercise of outstanding options		Weighted-average exercise price of outstanding options				Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column (a)) (in millions)
	Equity compensation plans approved by security holders	10.5		$	34.46			55		-1
	Total	10.5		$	34.46			55
	____________________
	-1	Included in this amount are 40.7 million securities available for future issuance under Autodesk’s ESP Plan.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Jan. 31, 2015
Income Tax Disclosure [Abstract]
Provision for income taxes	The provision for income taxes consists of the following:
		Fiscal year ended January 31,
		2015			2014			2013
	Federal:
	Current	$	(43.8	)	$	29.1		$	30.9
	Deferred	(11.9		)	(41.4		)	(13.3		)
	State:
	Current	(13.2		)	0.6			7.8
	Deferred	9			—			(18.6		)
	Foreign:
	Current	69.5			63.9			54.3
	Deferred	(8.4		)	(1.1		)	1.5
		$	1.2		$	51.1		$	62.6
Differences between the U.S. statutory rate and the aggregate income tax provision	The differences between the U.S. statutory rate and the aggregate income tax provision are as follows:
		Fiscal year ended January 31,
		2015			2014			2013
	Income tax provision at U.S. Federal statutory rate	$	29		$	98		$	108.5
	State income tax benefit, net of the U.S. Federal benefit	(4.0		)	(2.9		)	(1.7		)
	Foreign income taxed at rates different from the U.S. statutory rate	(40.0		)	(57.1		)	(54.5		)
	U.S. valuation allowance	2.9			2.1			1.7
	Tax effect of non-deductible stock-based compensation	15.7			10.8			21.1
	Research and development tax credit benefit	(7.2		)	(8.8		)	(7.0		)
	Tax (benefit) expense from closure of income tax audits and changes in uncertain tax positions	(0.7		)	3.6			(2.8		)
	Tax effect of officer compensation in excess of $1.0 million	2.4			3			1.8
	U.S. Manufacturer's deduction	—			(0.1		)	(4.9		)
	Other	3.1			2.5			0.4
		$	1.2		$	51.1		$	62.6
Components of Deferred Tax Assets and Liabilities	Significant components of Autodesk’s deferred tax assets and liabilities are as follows:
		January 31,
		2015			2014
	Stock-based compensation	$	39.9		$	37.4
	Research and development tax credit carryforwards	62.6			78.4
	Foreign tax credit carryforwards	—			16.3
	Accrued compensation and benefits	43.6			38.6
	Other accruals not currently deductible for tax	18.4			14.5
	Purchased technology and capitalized software	13.2			23.4
	Fixed assets	16.2			17.5
	Tax loss carryforwards	16			12.6
	Deferred Revenue	48			33.1
	Other	7.4			5.1
	Total deferred tax assets	265.3			276.9
	Less: valuation allowance	(70.8		)	(67.2		)
	Net deferred tax assets	194.5			209.7
	Unremitted earnings of foreign subsidiaries	(9.4		)	(21.8		)
	Total deferred tax liability	(9.4		)	(21.8		)
	Net deferred tax assets	$	185.1		$	187.9
Unrecognized Tax Benefits Reconciliation, Table	A reconciliation of the beginning and ending amount of the gross unrecognized tax benefits is as follows:
		Fiscal Year Ended January 31,
		2015			2014			2013
	Gross unrecognized tax benefits at the beginning of the fiscal year	$	222.1		$	212.7		$	201.1
	Increases for tax positions of prior years	3.2			1.8			0.4
	Decreases for tax positions of prior years	(2.5		)	(0.3		)	(0.4		)
	Increases for tax positions related to the current year	33.2			15.3			17.8
	Decreases relating to settlements with taxing authorities	(5.4		)	(4.6		)	(3.0		)
	Reductions as a result of lapse of the statute of limitations	(4.8		)	(2.8		)	(3.2		)
	Gross unrecognized tax benefits at the end of the fiscal year	$	245.8		$	222.1		$	212.7

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Jan. 31, 2015
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table summarizes the fair value of the assets acquired and liabilities assumed by major class for each of the business combinations and technology acquisitions completed during the fiscal year ended January 31, 2014:
		Graitec			Other
	Developed technologies	$	15.9		$	15.9
	Customer relationships	2.2			2.8
	Trade name	1.7			1.8
	Goodwill	73.4			67
	Deferred tax (liability) asset	(6.2		)	0.7
	Net tangible assets	—			1.5
	Total	$	87		$	89.7
	The following table summarizes the fair value of the assets acquired and liabilities assumed by major class for each of the business combinations and technology acquisitions completed during the fiscal year ended January 31, 2015:
		Shotgun			Within			Delcam			Other
	Developed technologies	$	5.4		$	4.6		$	28.9		$	39
	Customer relationships and other non-current intangible assets	7.5			3.6			39.7			9.8
	Trade name	1.6			1.2			16.5			6.3
	Goodwill	43.2			80.6			190.4			180.6
	Deferred Revenue (current and non-current)	(0.7		)	—			(10.4		)	(0.4		)
	Deferred tax liability	(2.6		)	(1.7		)	(13.2		)	(2.1		)
	Net tangible assets (liabilities)	0.1			(0.3		)	32.7			1.3
		$	54.5		$	88		$	284.6		$	234.5

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Jan. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Aggregate Future Minimum Lease Payments	At January 31, 2015, the aggregate future minimum lease payments required were as follows:
	2016	$	55.4
	2017	47.3
	2018	40.7
	2019	29.1
	2020	19.5
	Thereafter	32.6
		224.6
	Less: Sublease income	1.9
		$	222.7
Rent Expense Related to Operating Leases	Rent expense related to these operating leases recognized on a straight-line basis over the lease period, was as follows:
		Fiscal Year Ended January 31,
		2015		2014		2013
	Rent expense	$	55	$	50.2	$	56.1

Interest_And_Other_Income_net_

Interest And Other Income, net (Tables)	12 Months Ended
	Jan. 31, 2015
Interest and Other Income, net [Abstract]
Interest and Other (Expense) Income, net	Interest and other (expense) income, net, consists of the following:
		Fiscal Year Ended January 31,
		2015			2014			2013
	Interest and investment (expense) income, net	$	(13.2	)	$	(9.8	)	$	4.9
	(Loss) gain on foreign currency	(3.9		)	4			1.2
	Loss on strategic investments	(23.3		)	(1.8		)	(4.0		)
	Other income	2.7			2.7			2
	Interest and other (expense) income, net	$	(37.7	)	$	(4.9	)	$	4.1

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Jan. 31, 2015
Accumulated Other Comprehensive Income (loss) [Abstract]
Schedule of Accumulated Other Comprehensive (Loss) Income	Accumulated other comprehensive loss, net of taxes, was comprised of the following:
		Net Unrealized Gains (Losses) on Derivative Instruments			Net Unrealized Gains (Losses) on Available for Sale Securities			Defined Benefit Pension Components			Foreign Currency Translation Adjustments			Total (1)
	Balances, January 31, 2013	$	2.8		$	2.9		$	(13.1	)	$	1.7		$	(5.7	)
	Other comprehensive income (loss) before reclassifications	11.1			(0.2		)	3.9			(2.0		)	12.8
	Pre-tax (gains) losses reclassified from accumulated other comprehensive income	(11.5		)	(1.2		)	0.9			—			(11.8		)
	Tax effects	1.1			0.3			0.6			2.1			4.1
	Net current period other comprehensive income (loss)	0.7			(1.1		)	5.4			0.1			5.1
	Balances, January 31, 2014	3.5			1.8			(7.7		)	1.8			(0.6		)
	Other comprehensive income (loss) before reclassifications	47			(1.7		)	(18.3		)	(80.7		)	(53.7		)
	Pre-tax (gains) losses reclassified from accumulated other comprehensive income	(7.0		)	1.7			0.5			—			(4.8		)
	Tax effects	(0.7		)	(0.2		)	1.8			4.9			5.8
	Net current period other comprehensive income (loss)	39.3			(0.2		)	(16.0		)	(75.8		)	(52.7		)
	Balances, January 31, 2015	$	42.8		$	1.6		$	(23.7	)	$	(74.0	)	$	(53.3	)
	(1) For comparability, the presentation of prior period balances were adjusted to align with current year presentation.

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	12 Months Ended
	Jan. 31, 2015
Earnings Per Share [Abstract]
Schedule of Calculation of Numerator and Denominator in Earnings Per Share	The following table sets forth the computation of the numerators and denominators used in the basic and diluted net income per share amounts:
		Fiscal Year Ended January 31,
		2015		2014		2013
	Numerator:
	Net income	$	81.8	$	228.8	$	247.4
	Denominator:
	Denominator for basic net income per share—weighted average shares	227.1		224		226.4
	Effect of dilutive securities	5.3		5.6		5.3
	Denominator for dilutive net income per share	232.4		229.6		231.7
	Basic net income per share	$	0.36	$	1.02	$	1.09
	Diluted net income per share	$	0.35	$	1	$	1.07

Segments_Tables

Segments (Tables)	12 Months Ended
	Jan. 31, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Information concerning the operations of Autodesk’s reportable segments is as follows:
		Fiscal year ended January 31,
		2015			2014			2013
	Net revenue:
	Architecture, Engineering, and Construction (1)	$	872.6		$	730.6		$	701.1
	Platform Solutions and Emerging Business (1)	796.7			789.2			843
	Manufacturing	675.6			579.4			573.8
	Media and Entertainment (1)	167.3			174.7			194.3
		$	2,512.20		$	2,273.90		$	2,312.20
	Gross profit:
	Architecture, Engineering, and Construction (1)	$	785.8		$	663.8		$	642
	Platform Solutions and Emerging Business (1)	712.3			716.8			788.8
	Manufacturing	604			531.5			531.3
	Media and Entertainment	127.3			137.8			156.5
	Unallocated (2)	(59.3		)	(50.3		)	(44.9		)
		$	2,170.10		$	1,999.60		$	2,073.70
	Depreciation, amortization and accretion:
	Architecture, Engineering, and Construction	$	1.3		$	0.2		$	0.2
	Platform Solutions and Emerging Business	6.8			5.5			1.8
	Manufacturing	3			0.9			0.5
	Media and Entertainment	0.3			0.2			0.4
	Unallocated	134.5			122.1			124.9
		$	145.9		$	128.9		$	127.8
	_______________
	-1	Prior period segment revenue amounts have been updated to conform to the current period's presentation.
	-2	Unallocated amounts primarily relate to corporate expenses and other costs and expenses that are managed outside the reportable segments, including stock-based compensation expense.
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	Information regarding Autodesk’s operations by geographic area is as follows:
		Fiscal year ended January 31,
		2015			2014			2013
	Net revenue:
	Americas
	U.S.	$	736.4		$	672.3		$	672.1
	Other Americas	161.6			146.6			164.1
	Total Americas	898			818.9			836.2
	Europe, Middle East, and Africa	980			851.8			868.5
	Asia Pacific
	Japan	269			274.5			278.3
	Other Asia Pacific	365.2			328.7			329.2
	Total Asia Pacific	634.2			603.2			607.5
	Total net revenue	$	2,512.20		$	2,273.90		$	2,312.20
	Information regarding Autodesk’s long-lived assets by geographic area is as follows:
		January 31,
		2015			2014
	Long-lived assets (1):
	Americas
	U.S.	$	108.8		$	89
	Other Americas	3.1			2.9
	Total Americas	111.9			91.9
	Europe, Middle East, and Africa	25			27.2
	Asia Pacific	22.3			11.2
	Total long-lived assets	$	159.2		$	130.3
	____________________
	-1	Long-lived assets exclude deferred tax assets, marketable securities, goodwill, and other intangible assets. Prior period amounts have been updated to conform to the current period's presentation.

Retirement_Benefit_Plans_Table

Retirement Benefit Plans (Tables)	12 Months Ended
	Jan. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Schedule of Changes in Projected Benefit Obligations	The changes in the projected benefit obligations and plan assets for the plans described above were as follows:
		Fiscal year ended January 31,
		2015				2014
	Beginning projected benefit obligation	$	62.2			$	61.5
	Service cost	4.6				5.4
	Interest cost	3.9				1.1
	Actuarial loss (gain)	18.8				(3.2		)
	Benefits paid	(7.5		)		(5.9		)
	Foreign currency exchange rate changes	(1.2		)		0.8
	Curtailments and settlements	(2.9		)		—
	Contributions by plan participants	5.9				2.5
	Business combinations	60.9				—
	Ending projected benefit obligation	$	144.7			$	62.2
	Beginning fair value of plan assets	$	40.7			$	37.5
	Actual return on plan assets	4.1				0.9
	Contributions paid by employer	4.9				5.2
	Contributions paid by plan participants	5.9				2.5
	Benefit payments	(7.5		)		(5.9		)
	Curtailments and settlements	(2.9		)		—
	Foreign currency exchange rate changes	(1.2		)		0.5
	Business combinations	60.2				—
	Ending fair value of plan assets	$	104.2			$	40.7
	Funded status	$	(40.5	)		$	(21.5	)
Schedule of Amounts Recognized in Balance Sheet	The amounts recognized on the consolidated balance sheets at the end of each period were as follows:
		Fiscal Year Ended January 31,
		2015				2014
	Other long-term liabilities	$	40.5			$	21.5
	Accumulated other comprehensive loss, before tax	26.6				8.7
	Net amount recognized	$	67.1			$	30.2
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	Included in the aggregate data in the following tables are the amounts applicable to our defined benefit plans, with accumulated benefit obligations in excess of plan assets, as well as plans with projected benefit obligations in excess of plan assets. Amounts related to such plans at the end of each period were as follows:
			Fiscal Year Ended January 31,
			2015				2014
	Plans with accumulated benefit obligations in excess of plan assets:
	Accumulated benefit obligations		$	124			$	45.3
	Plan Assets		103.9				40.7
	Plans with projected benefit obligations in excess of plan assets:
	Projected benefit obligations		$	144.7			$	62.2
	Plan Assets		104.2				40.7
Schedule of Allocation of Plan Assets	Pension plan assets measured at fair value on a recurring basis consisted of the following investment categories at the end of each period as follows:
		Fiscal Year Ended January 31,
		2015													2014
		Level 1				Level 2				Level 3			Total		Total
	Investment fund	$	55.7			$	4.9			$	—		$	60.6	$	—
	Insurance contracts	—				43.5				—			43.5		40.2
	Total assets measured at fair value	55.7				48.4				—			104.1		40.2
	Cash	0.1				—				—			0.1		0.5
	Total pension plan assets at fair value	$	55.8			$	48.4			$	—		$	104.2	$	40.7
Schedule of Expected Benefit Payments	Estimated benefit payments over the next 10 fiscal years are as follows:
		Pension Benefits
	2016	$	3.5
	2017	3.4
	2018	3.5
	2019	3.3
	2020	3.1
	2021-2025	17.5
Schedule of Net Benefit Costs	The components of net periodic pension cost for the defined benefit pension plans for fiscal 2015, 2014, and 2013 are as follows:
		Fiscal Year Ended January 31,
		2015				2014				2013
	Service cost for benefits earned during the period	$	4.6			$	5.4			$	4.5
	Interest cost on projected benefit obligation	3.9				1.1				1.3
	Expected return on plan assets	(4.6		)		(0.8		)		(0.8		)
	Amortization of prior service credit	(0.1		)		(0.1		)		(0.1		)
	Amortization of loss	0.6				1				0.7
	Net periodic benefit cost	$	4.4			$	6.6			$	5.6
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	The components of other comprehensive income for the defined benefit pension plans before taxes for fiscal 2015, 2014, and 2013 are as follows:
		Fiscal Year Ended January 31,
		2015				2014				2013
	Net loss (gain) for period	$	18.4			$	(3.9	)		$	6.3
	Amortization of prior service credit	0.1				0.1				0.1
	Amortization of net loss	(0.6		)		(1.0		)		(0.7		)
	Other comprehensive loss (income)	$	17.9			$	(4.8	)		$	5.7
Schedule of Net Periodic Benefit Cost Not yet Recognized	The amounts recorded in accumulated other comprehensive income loss before taxes at the end of each period were as follows:
		Fiscal Year Ended January 31,
		2015				2014
	Net prior service credit	$	(1.8	)		$	(1.9	)
	Net actuarial loss	28.4				10.6
	Accumulated other comprehensive loss, before tax	$	26.6			$	8.7
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year	The estimated amounts that will be amortized from AOCI into net periodic benefit cost over the next fiscal year for the qualified defined benefit pension plan and other benefit plans are as follows:
		Pension Benefits
	Amortization of prior service credit	$	0.1
	Amortization of the net loss	(1.5		)
	Total amortization	$	(1.4	)
Schedule of Assumptions Used	Weighted average actuarial assumptions used to determine benefit obligations for the plans at the end of each period were as follows:
		Fiscal Year Ended January 31,
		2015			2014			2013
	Discount rate	2.4	%		2.2	%		1.8	%
	Rate of compensation increase	1.2	%		2.2	%		2	%
	Weighted average actuarial assumptions used to determine costs for the plans for each period were as follows:
		Fiscal Year Ended January 31,
		2015			2014			2013
	Discount rate	3.3	%		2.3	%		1.8	%
	Expected long-term rate of return on plan assets	3.9	%		1.9	%		2	%
	Rate of compensation increase	2.2	%		2.2	%		2.1	%

Restructuring_Reserves_Tables

Restructuring Reserves (Tables)	12 Months Ended
	Jan. 31, 2015
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Reserve by Type of Cost	The following table sets forth the restructuring activities for the fiscal years ended January 31, 2015 and 2014:
		Balances, January 31, 2014		Additions		Payments			Adjustments (1)			Balances, January 31, 2015
	Fiscal 2013 Plan
	Employee termination costs	$	0.1	$	—	$	—		$	(0.1	)	$	—
	Lease termination and asset costs	0.2		0.3		(0.3		)				0.2
	Fiscal 2014 Plan
	Employee termination costs	3.5		2.5		(6.0		)	—			—
	Lease termination and asset costs	1.3		0.3		(0.5		)	0.3			1.4
	Total	$	5.1	$	3.1	$	(6.8	)	$	0.2		$	1.6
	Current portion (2)	$	4									$	0.7
	Non-current portion (2)	1.1										0.9
	Total	$	5.1									$	1.6
	____________________
	-1	Adjustments include the impact of foreign currency translation.
	-2	The current and non-current portions of the reserve are recorded in the Consolidated Balance Sheets under “Other accrued liabilities” and “Other liabilities,” respectively.
		Balances, January 31, 2013		Additions		Payments			Adjustments (1)			Balances, January 31, 2014
	Fiscal 2013 Plan
	Employee termination costs	$	4.5	$	0.8	$	(5.0	)	(0.2		)	$	0.1
	Lease termination and asset costs	2.8		1.5		(4.2		)	0.1			0.2
	Fiscal 2014 Plan
	Employee termination costs	—		9.4		(5.7		)	(0.2		)	3.5
	Lease termination and asset costs	—		1.1					0.2			1.3
	Total	$	7.3	$	12.8	$	(14.9	)	$	(0.1	)	$	5.1
	Current portion (2)	$	5.8									$	4
	Non-current portion (2)	1.5										1.1
	Total	$	7.3									$	5.1
	_______________
	-1	Adjustments include the impact of foreign currency translation.
	-2	The current and non-current portions of the reserve are recorded in the Consolidated Balance Sheets under “Other accrued liabilities” and “Other liabilities,” respectively.

Selected_Quarterly_Financial_I1

Selected Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Jan. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information	Summarized quarterly financial information for fiscal 2015 and 2014 is as follows:
	2015	1st quarter			2nd quarter			3rd quarter			4th quarter			Fiscal year
	Net revenue	$	592.5		$	637.1		$	618		$	664.6		$	2,512.20
	Gross profit	513.8			549.2			532			575.1			2,170.10
	Income from operations	42.2			49.9			14.6			14			120.7
	Provision for income taxes	(7.3		)	(11.6		)	(0.9		)	18.6			(1.2		)
	Net income	28.3			31.3			10.7			11.5			81.8
	Basic net income per share	$	0.12		$	0.14		$	0.05		$	0.05		$	0.36
	Diluted net income per share	$	0.12		$	0.13		$	0.05		$	0.05		$	0.35
	Income from operations includes the following items:
	Stock-based compensation expense	$	33.6		$	39.8		$	43.1		$	49.1		$	165.6
	Amortization of acquisition related intangibles	23.9			24.6			22.6			21.9			93
	Restructuring charges, net	2.3			0.8			—			—			3.1
	2014	1st quarter			2nd quarter			3rd quarter			4th quarter			Fiscal year
	Net revenue	$	570.4		$	561.7		$	555.2		$	586.6		$	2,273.90
	Gross profit	502.9			493.9			488.1			514.7			1,999.60
	Income from operations	81.4			83.6			68.1			51.7			284.8
	Provision for income taxes	(17.0		)	(20.1		)	(11.6		)	(2.4		)	(51.1		)
	Net income	55.6			61.7			57.6			53.9			228.8
	Basic net income per share	$	0.25		$	0.28		$	0.26		$	0.24		$	1.02
	Diluted net income per share	$	0.24		$	0.27		$	0.25		$	0.23		$	1
	Income from operations includes the following items:
	Stock-based compensation expense	$	33.5		$	31		$	31.6		$	36.1		$	132.2
	Amortization of acquisition related intangibles	21.6			20.3			18.2			20.6			80.7
	Restructuring charges, net	0.4			1.7			4.4			6.3			12.8

Business_and_Summary_of_Signif3

Business and Summary of Significant Accounting Policies - Reclassifications (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
Accounting Policies [Abstract]
Decrease to License and other revenue		($26.50)
Increase to Subscription revenue		26.5
Decrease to Cost of license and other revenue		-32.1
Increase to Cost of subscription revenue		32.1
(Decrease) to general and administrative	-36.5	-42.1
Increase to amortization of purchased intangibles	$36.50	$42.10

Business_and_Summary_of_Signif4

Business and Summary of Significant Accounting Policies - Accounts Receivable, Net (Details) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Millions, unless otherwise specified
Accounting Policies [Abstract]
Trade accounts receivable	$495.40	$464.60
Less: Allowance for doubtful accounts	-6.3	-4.9
Product returns reserve	-2.6	-4
Partner programs and other obligations	-27.6	-32
Accounts receivable, net	$458.90	$423.70

Business_and_Summary_of_Signif5

Business and Summary of Significant Accounting Policies - Concentration of Credit Risk (Details) (USD $)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Concentration Risk [Line Items]
Maximum borrowing capacity	400,000,000
Tech Data | Sales Revenue, Net
Concentration Risk [Line Items]
Concentration risk, percentage	25.00%	24.00%	23.00%
Tech Data | Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	22.00%	24.00%
United States
Concentration Risk [Line Items]
Concentration risk, percentage	19.00%	25.00%
Other Americas
Concentration Risk [Line Items]
Concentration risk, percentage	1.00%	1.00%
Europe, Middle East, and Africa (“EMEA”)
Concentration Risk [Line Items]
Concentration risk, percentage	56.00%	57.00%
Asia Pacific (“APAC”)
Concentration Risk [Line Items]
Concentration risk, percentage	24.00%	17.00%

Business_and_Summary_of_Signif6

Business and Summary of Significant Accounting Policies - Computer Equipment, Software, Furniture and Leasehold Improvements, Net (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Property, Plant and Equipment [Abstract]
Depreciation	$52.10	$47.20	$45.60
Computer hardware, at cost	194	163
Computer software, at cost	84.9	80.9
Leasehold improvements, land, and buildings, at cost	176.3	163.7
Furniture and equipment, at cost	53	51.7
Computer software, hardware, leasehold improvements, furniture, and equipment, at cost	508.2	459.3
Less: Accumulated depreciation	-349	-329
Computer software, hardware, leasehold improvements, furniture, and equipment, net	159.2	130.3
Write off of fully depreciated assets	$25.80
Software and Software Development Costs
Property, Plant and Equipment [Abstract]
Useful Life	3 years
Minimum
Property, Plant and Equipment [Abstract]
Useful Life	3 years
Maximum
Property, Plant and Equipment [Abstract]
Useful Life	5 years

Business_and_Summary_of_Signif7

Business and Summary of Significant Accounting Policies - Other Intangible Assets and Related Accumulated Amortization (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of intangible assets	$39.80		$36.50		$42.10
Developed technologies, at cost	538.4		462.4
Customer relationships, trade names, patents, and user lists, at cost	348.9	[1]	268.1	[1]
Other intangible assets, gross	887.3		730.5
Less: Accumulated amortization	-715.4		-626.2
Other intangible assets, net	171.9		104.3
Weighted average useful life	4 years 2 months 5 days
Customer Relationships, Trade Names, Patents, and User List
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of intangible assets	$92.90		$80.70		$82
Customer Relationships, Trade Names, Patents, and User List | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Customer Relationships, Trade Names, Patents, and User List | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years
[1]	Included as a net balance in “Other assets” in the Consolidated Balance Sheet. Customer relationships and trade names include the effects of foreign currency translation.

Expected_Future_Amortization_E

- Expected Future Amortization Expense for Purchased Technologies, Customer Relationships and Trade Names (Details) (USD $)	Jan. 31, 2015
In Millions, unless otherwise specified
Expected Future Amortization Expense for Purcahsed Technologies, Customer Relationships and Trade Name [Abstract]
2016	$73.20
2017	49.7
2018	24
2019	15.5
2020	5.3
Thereafter	4.2
Total	$171.90

Business_and_Summary_of_Signif8

Business and Summary of Significant Accounting Policies - Changes In the Carrying Amount of Goodwill (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Feb. 06, 2014	29-May-14
Goodwill [Roll Forward]
Goodwill before accumulated impairments	$1,159.10	$1,020.70
Accumulated impairment losses	-149.2	-149.2
Goodwill, beginning of period	1,009.90	871.5
Effect of foreign currency translation, purchase accounting adjustments, and other	-54.9	-2
Goodwill before accumulated impairments	1,605.40	1,159.10	1,020.70
Accumulated impairment losses	-149.2	-149.2	-149.2
Goodwill, end of period	1,456.20	1,009.90	871.5
Impairment loss	0	0	0
Delcam plc
Goodwill [Roll Forward]
Goodwill, beginning of period				166
Goodwill acquired during period	196.1
Goodwill, end of period	190.4			166
Within Technologies Limited
Goodwill [Roll Forward]
Goodwill, beginning of period					78.9
Goodwill acquired during period	80.6
Goodwill, end of period	80.6				78.9
Shotgun Software Inc.
Goodwill [Roll Forward]
Goodwill acquired during period	43.2
Goodwill, end of period	43.2
Graitec SA
Goodwill [Roll Forward]
Goodwill acquired during period		73.4
Goodwill acquired from other acquisitions
Goodwill [Roll Forward]
Goodwill acquired during period	181.3	67
Platform Solutions and Emerging Business
Goodwill [Roll Forward]
Goodwill before accumulated impairments	142.3	129.5
Accumulated impairment losses	0	0
Goodwill, beginning of period	142.3	129.5
Effect of foreign currency translation, purchase accounting adjustments, and other	-13.2	0
Goodwill before accumulated impairments	327.5	142.3
Accumulated impairment losses	0	0
Goodwill, end of period	327.5	142.3
Platform Solutions and Emerging Business | Delcam plc
Goodwill [Roll Forward]
Goodwill acquired during period	0
Platform Solutions and Emerging Business | Within Technologies Limited
Goodwill [Roll Forward]
Goodwill acquired during period	80.6
Platform Solutions and Emerging Business | Shotgun Software Inc.
Goodwill [Roll Forward]
Goodwill acquired during period	0
Platform Solutions and Emerging Business | Graitec SA
Goodwill [Roll Forward]
Goodwill acquired during period		0
Platform Solutions and Emerging Business | Goodwill acquired from other acquisitions
Goodwill [Roll Forward]
Goodwill acquired during period	117.8	12.8
Architecture, Engineering, and Construction
Goodwill [Roll Forward]
Goodwill before accumulated impairments	415.2	310.3
Accumulated impairment losses	0	0
Goodwill, beginning of period	415.2	310.3
Effect of foreign currency translation, purchase accounting adjustments, and other	-16.3	-0.5
Goodwill before accumulated impairments	427	415.2
Accumulated impairment losses	0	0
Goodwill, end of period	427	415.2
Architecture, Engineering, and Construction | Delcam plc
Goodwill [Roll Forward]
Goodwill acquired during period	0
Architecture, Engineering, and Construction | Within Technologies Limited
Goodwill [Roll Forward]
Goodwill acquired during period	0
Architecture, Engineering, and Construction | Shotgun Software Inc.
Goodwill [Roll Forward]
Goodwill acquired during period	0
Architecture, Engineering, and Construction | Graitec SA
Goodwill [Roll Forward]
Goodwill acquired during period		73.4
Architecture, Engineering, and Construction | Goodwill acquired from other acquisitions
Goodwill [Roll Forward]
Goodwill acquired during period	28.1	32
Manufacturing
Goodwill [Roll Forward]
Goodwill before accumulated impairments	411.6	389.9
Accumulated impairment losses	0	0
Goodwill, beginning of period	411.6	389.9
Effect of foreign currency translation, purchase accounting adjustments, and other	-9	-0.5
Goodwill before accumulated impairments	422.7	411.6
Accumulated impairment losses	0	0
Goodwill, end of period	422.7	411.6
Manufacturing | Delcam plc
Goodwill [Roll Forward]
Goodwill acquired during period	0
Manufacturing | Within Technologies Limited
Goodwill [Roll Forward]
Goodwill acquired during period	0
Manufacturing | Shotgun Software Inc.
Goodwill [Roll Forward]
Goodwill acquired during period	0
Manufacturing | Graitec SA
Goodwill [Roll Forward]
Goodwill acquired during period		0
Manufacturing | Goodwill acquired from other acquisitions
Goodwill [Roll Forward]
Goodwill acquired during period	20.1	22.2
Media and Entertainment
Goodwill [Roll Forward]
Goodwill before accumulated impairments	190	191
Accumulated impairment losses	-149.2	-149.2
Goodwill, beginning of period	40.8	41.8
Effect of foreign currency translation, purchase accounting adjustments, and other	-3.3	-1
Goodwill before accumulated impairments	245.2	190
Accumulated impairment losses	-149.2	-149.2
Goodwill, end of period	96	40.8
Media and Entertainment | Delcam plc
Goodwill [Roll Forward]
Goodwill acquired during period	0
Media and Entertainment | Within Technologies Limited
Goodwill [Roll Forward]
Goodwill acquired during period	0
Media and Entertainment | Shotgun Software Inc.
Goodwill [Roll Forward]
Goodwill acquired during period	43.2
Media and Entertainment | Graitec SA
Goodwill [Roll Forward]
Goodwill acquired during period		0
Media and Entertainment | Goodwill acquired from other acquisitions
Goodwill [Roll Forward]
Goodwill acquired during period	15.3	0
Delcam plc
Goodwill [Roll Forward]
Goodwill before accumulated impairments	0
Accumulated impairment losses	0
Goodwill, beginning of period	0
Effect of foreign currency translation, purchase accounting adjustments, and other	-13.1
Goodwill before accumulated impairments	183
Accumulated impairment losses	0
Goodwill, end of period	183
Delcam plc | Delcam plc
Goodwill [Roll Forward]
Goodwill acquired during period	196.1
Delcam plc | Within Technologies Limited
Goodwill [Roll Forward]
Goodwill acquired during period
Delcam plc | Shotgun Software Inc.
Goodwill [Roll Forward]
Goodwill acquired during period
Delcam plc | Goodwill acquired from other acquisitions
Goodwill [Roll Forward]
Goodwill acquired during period

Business_and_Summary_of_Signif9

Business and Summary of Significant Accounting Policies - Stock Based Compensation Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$165.60	$132.20	$156.30
Tax benefit	-45.2	-36.4	-35.5
Stock-based compensation expense related to stock awards and ESP Plan purchases, net	120.4	95.8	120.8
Cost of license and other revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	4.6	3.8	3.7
Cost of subscription
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	4.3	2.2	1.5
Marketing and sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	72.4	58.6	64.3
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	56	43.7	61.8
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$28.30	$23.90	$25

Recovered_Sheet1

Business and Summary of Significant Accounting Policies - Assumption Used to Estimate the Fair Value of Stock-Based Awards (Details)	12 Months Ended
	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
Performance Stock Unit
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Range of expected volatilities	30.00%	[1]
Expected dividends	0.00%	[1]
Range of risk-free interest rates	0.10%	[1]
Employee Qualified Stock Purchase Plan 1998 ESP Plan
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Expected dividends	0.00%		0.00%		0.00%
Employee Qualified Stock Purchase Plan 1998 ESP Plan | Minimum
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Range of expected volatilities	29.00%		27.00%		41.00%
Range of expected lives	2 years		2 years		2 years
Range of risk-free interest rates	0.00%		0.10%		0.10%
Employee Qualified Stock Purchase Plan 1998 ESP Plan | Maximum
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Range of expected volatilities	33.00%		36.00%		44.00%
Range of expected lives	6 months		6 months		6 months
Range of risk-free interest rates	0.60%		0.40%		0.30%
Stock Options Plan
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Range of expected volatilities			34.00%	[1]
Expected dividends			0.00%	[1]	0.00%	[2]
Range of risk-free interest rates			0.10%	[1]
Stock Options Plan | Minimum
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Range of expected volatilities					41.00%	[2]
Range of expected lives					4 years 7 months 6 days	[2]
Range of risk-free interest rates					0.50%	[2]
Stock Options Plan | Maximum
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Range of expected volatilities					45.00%	[2]
Range of expected lives					3 years 7 months 6 days	[2]
Range of risk-free interest rates					0.80%	[2]
[1]	Autodesk did not grant PSUs in fiscal 2013 that were subject to market conditions.
[2]	Autodesk did not grant stock options in fiscal 2015 or 2014.

Recovered_Sheet2

Business and Summary of Significant Accounting Policies - Advertising Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Accounting Policies [Abstract]
Advertising Expense	$23.90	$15.60	$15.60

Recovered_Sheet3

Business and Summary of Significant Accounting Policies - New Accounting Standards (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015
Long-term Taxes Payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$81.90
Long-term Deferred Tax Asset
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$81.90

Financial_Instruments_Cost_and

Financial Instruments - Cost and Fair Value of Financial Instruments (Details) (USD $)	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013	Jan. 31, 2012
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents	$1,410.60		$1,853		$1,612.20	$1,156.90
Derivative Instruments And Hedges at Amortized Cost	3.5	[1]	10.8	[1]
Unrealized Gain on Foreign Currency Derivatives	19.5	[1]	14.8	[1]
Unrealized Loss on Foreign Currency Derivatives	-7	[1]	-6	[1]
Derivative Contracts, Fair Value	16	[1]	19.6	[1]
Amortized Cost Securities	1,592.60		1,545.30
Unrealized Gain on Securities	26.6		22.4
Unrealized Loss on Securities	-9.4		-10.5
Total	1,609.80		1,557.20
Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Trading Securities, Cost	36.9		35.6
Trading Securities, Unrealized Holding Gain	3.4		3.3
Trading Securities, Unrealized Holding Loss	0		0
Trading Securities	40.3		38.9
Other Assets
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost			21.4	[2]
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain			3.2	[2]
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss			-4.4	[2]
Available-for-sale Securities, Fair Value			20.2	[2]
Convertible Debt Securities, Amortized Cost	4.7	[3]
Convertible Debt Securities, Unrealized Gains	2.5	[3]
Convertible Debt Securities, Unrealized Losses	-2.1	[3]
Convertible Debt Securities, Fair Value	5.1	[3]
Level 1
Schedule of Available-for-sale Securities [Line Items]
Derivative Contracts, Fair Value	0	[1]	0	[1]
Total	1,042		521.1
Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Trading Securities	40.3		38.9
Level 1 | Other Assets
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0	[2]
Convertible Debt Securities, Fair Value	0	[3]
Level 2
Schedule of Available-for-sale Securities [Line Items]
Derivative Contracts, Fair Value	15.1	[1]	10.5	[1]
Total	561.8		1,006.80
Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Trading Securities	0		0
Level 2 | Other Assets
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0	[2]
Convertible Debt Securities, Fair Value	0	[3]
Level 3
Schedule of Available-for-sale Securities [Line Items]
Derivative Contracts, Fair Value	0.9	[1]	9.1	[1]
Total	6		29.3
Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Trading Securities	0		0
Level 3 | Other Assets
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			20.2	[2]
Convertible Debt Securities, Fair Value	5.1	[3]
Agency bond | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	37.9		42.7
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0		0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	0		0
Available-for-sale Securities, Fair Value	37.9		42.7
Agency bond | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	50.6		43.3
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0.2		0.1
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	0		0
Available-for-sale Securities, Fair Value	50.8		43.4
Agency bond | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	37.9		42.7
Agency bond | Level 1 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	50.8		43.4
Agency bond | Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Agency bond | Level 2 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Agency bond | Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Agency bond | Level 3 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Corporate debt securities | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	148
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0.1
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	-0.1
Available-for-sale Securities, Fair Value	148
Corporate debt securities | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	199.4		179.7
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0.6		0.7
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	-0.2		-0.1
Available-for-sale Securities, Fair Value	199.8		180.3
Corporate debt securities | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	148
Corporate debt securities | Level 1 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	199.8		180.3
Corporate debt securities | Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0
Corporate debt securities | Level 2 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Corporate debt securities | Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0
Corporate debt securities | Level 3 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Municipal bond | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	29.2		11.7
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0.1		0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	0		0
Available-for-sale Securities, Fair Value	29.3		11.7
Municipal bond | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	13.3		43.5
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0.1		0.3
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	0		0
Available-for-sale Securities, Fair Value	13.4		43.8
Municipal bond | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	29.3		11.7
Municipal bond | Level 1 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	13.4		43.8
Municipal bond | Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Municipal bond | Level 2 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Municipal bond | Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Municipal bond | Level 3 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Certificate of deposit | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	101.9
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	0
Available-for-sale Securities, Fair Value	101.9
Certificate of deposit | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	101.9
Commercial paper | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	258.4
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	0
Available-for-sale Securities, Fair Value	258.4
Commercial paper | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0
Commercial paper | Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	258.4
Commercial paper | Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0
U.S. government agency securities | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost			11.3
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain			0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss			0
Available-for-sale Securities, Fair Value			11.3
U.S. government agency securities | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	8.9		9.8
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain	0.1		0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss	0		0
Available-for-sale Securities, Fair Value	9		9.8
U.S. government agency securities | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			11.3
U.S. government agency securities | Level 1 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	9		9.8
U.S. government agency securities | Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0
U.S. government agency securities | Level 2 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
U.S. government agency securities | Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0
U.S. government agency securities | Level 3 | Marketable Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value	0		0
Commercial paper and corporate debt securities | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost			261
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain			0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss			0
Available-for-sale Securities, Fair Value			261
Commercial paper and corporate debt securities | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			95.4
Commercial paper and corporate debt securities | Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			165.6
Commercial paper and corporate debt securities | Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0
Time deposits | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost			37.1
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain			0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss			0
Available-for-sale Securities, Fair Value			37.1
Time deposits | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0
Time deposits | Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			37.1
Time deposits | Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0
Other securities | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost			11.4
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain			0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss			0
Available-for-sale Securities, Fair Value			11.4
Other securities | Level 1 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			11.4
Other securities | Level 2 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0
Other securities | Level 3 | Marketable Securities, Current
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Fair Value			0
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents	258.6	[4]
Cash and Cash Equivalents, Fair Value Disclosure	258.6	[4]
Corporate debt securities | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	258.6	[4]
Corporate debt securities | Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]
Corporate debt securities | Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]
Certificates of deposit and time deposits
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents			280.7	[4]
Cash and Cash Equivalents, Fair Value Disclosure			280.7	[4]
Certificates of deposit and time deposits | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			30.4	[4]
Certificates of deposit and time deposits | Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			250.3	[4]
Certificates of deposit and time deposits | Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure			0	[4]
Custody cash deposit
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents	141.5	[4]
Cash and Cash Equivalents, Fair Value Disclosure	141.5	[4]
Custody cash deposit | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	141.5	[4]
Custody cash deposit | Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]
Custody cash deposit | Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents	161	[4]	280.5	[4]
Cash and Cash Equivalents, Fair Value Disclosure	161	[4]	280.5	[4]
Commercial paper | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]	0	[4]
Commercial paper | Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	161	[4]	280.5	[4]
Commercial paper | Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]	0	[4]
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents	11.5	[4]	2	[4]
Cash and Cash Equivalents, Fair Value Disclosure	11.5	[4]	2	[4]
Municipal securities | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	11.5	[4]	2	[4]
Municipal securities | Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]	0	[4]
Municipal securities | Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]	0	[4]
Money market funds
Schedule of Available-for-sale Securities [Line Items]
Cash equivalents	127.3	[4]	262.8	[4]
Cash and Cash Equivalents, Fair Value Disclosure	127.3	[4]	262.8	[4]
Money market funds | Level 1
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	[4]	0	[4]
Money market funds | Level 2
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	127.3	[4]	262.8	[4]
Money market funds | Level 3
Schedule of Available-for-sale Securities [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	$0	[4]	$0	[4]
[1]	Included in “Prepaid expenses and other current assets,” "Other assets," or “Other accrued liabilities” in the accompanying Consolidated Balance Sheets.
[2]	Considered "available for sale" securities and included in "Other assets" in the accompanying Consolidated Balance Sheets.
[3]	Considered "available for sale" and included in "Other assets" in the accompanying Consolidated Balance Sheets.
[4]	Included in “Cash and cash equivalents” in the accompanying Consolidated Balance Sheets.

Financial_Instruments_Reconcil

Financial Instruments - Reconciliation of the Change in Level 3 Items (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$29.30	$32.40
Purchases	0.7	4.4
Settlements	-3.8	-4
Losses included in earnings	-20.8	-3.1	[1]
Gains included in OCI	0.6	-0.4	[1]
Ending Balance	6	29.3
Derivative Contracts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9.1	10.7
Purchases	0.1	1.3
Settlements	-0.8	0
Losses included in earnings	-7.5	-2.9	[1]
Gains included in OCI	0	0	[1]
Ending Balance	0.9	9.1
Convertible Debt Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	20.2	17.5
Purchases	0.6	3.1
Settlements	-3	0
Losses included in earnings	-13.3	0	[1]
Gains included in OCI	0.6	-0.4	[1]
Ending Balance	5.1	20.2
Taxable Auction-Rate Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0	4.2
Purchases	0	0
Settlements	0	-4
Losses included in earnings	0	-0.2	[1]
Gains included in OCI	0
Ending Balance	$0	$0
[1]	For comparability, the presentation of prior period balances were adjusted to align with current year presentation.

Financial_Instruments_Contract

Financial Instruments - Contractual Maturities of Types of Securities (Details) (USD $)	Jan. 31, 2015
In Millions, unless otherwise specified
Cost
Due in 1 year	$575.40
Due in 1 year through 5 years	276.9
Total	852.3
Fair Value
Due in 1 year	575.5
Due in 1 year through 5 years	278.1
Total	$853.60

Financial_Instruments_Availabl

Financial Instruments - Available for Sale Securities (Detail) (USD $)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Derivative [Line Items]
Cost Method Investments	$52,600,000	$49,800,000
Other than Temporary Impairment Losses, Investments	19,200,000	0
Available-for-sale securities gross gains (losses)	700,000	-200,000
Proceeds from Sale and Maturity of Marketable Securities	1,159,000,000	1,279,100,000
Notional amount of foreign currency forward contracts not designated as cash flow hedges	336,600,000	351,700,000
Net loss expected to be recognized into earnings	42,800,000	3,500,000	2,800,000
Foreign Exchange Contract
Derivative [Line Items]
Notional amount of foreign currency forward contracts not designated as cash flow hedges	$44,600,000	$205,500,000

Financial_Instruments_Fair_Val

Financial Instruments - Fair Value of Derivative Instruments (Detail) (USD $)	Jan. 31, 2015		Jan. 31, 2014
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]
Notional amount of foreign currency forward contracts not designated as cash flow hedges	$336.60		$351.70
Derivative asset, net	21.3		21.3
Derivative liability, net	5.4		1.7
Foreign Exchange Contracts
Derivatives, Fair Value [Line Items]
Notional amount of foreign currency forward contracts not designated as cash flow hedges	44.6		205.5
Designated as Hedging Instrument | Foreign Exchange Contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, net	20.4	[1]	4.4	[1]
Derivative asset, gross	23.8		5.9
Designated as Hedging Instrument | Foreign Exchange Contracts | Other Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, net	5.4	[2]	1.7	[2]
Derivative liability, gross	8.7		3.2
Not Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative asset, net	$0.90		$16.90
[1]	Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $23.8 million and $5.9 million at January 31, 2015 and January 31, 2014, respectively.
[2]	Considering Autodesk's master netting arrangements, these contracts are presented net settled. The gross balance is $8.7 million and $3.2 million at January 31, 2015 and January 31, 2014, respectively.

Financial_Instruments_Effects_

Financial Instruments - Effects of Derivative Instruments on Condensed Consolidated Statements of Operations (Detail) (Foreign Exchange Contracts, USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain recognized in accumulated other comprehensive income on derivatives (effective portion)	$46.40	$12.20	$5.10
Amount and location of gain reclassified from accumulated other comprehensive income into income (effective portion)	7	11.5	11.4
Designated as Hedging Instrument | Net revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount and location of gain reclassified from accumulated other comprehensive income into income (effective portion)	10.5	13.1	16
Designated as Hedging Instrument | Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
Amount and location of gain reclassified from accumulated other comprehensive income into income (effective portion)	-3.5	-1.6	-4.6
Designated as Hedging Instrument | Interest and other (expense) income, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount and location of gain (loss) recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing)	0.9	-0.1	-0.2
Not Designated as Hedging Instrument | Interest and other (expense) income, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount and location of (loss) gain recognized in income on derivative	($25.50)	$12.80	$1.50

Employee_and_Director_Stock_Pl2

Employee and Director Stock Plans - Schedule Of Share-based Compensation Options Activity (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jan. 31, 2015
Number of Shares
Options outstanding (in shares)	5.9
Granted (in shares)	0	[1]
Exercised (in shares)	-3.2
Canceled/Forfeited (in shares)	0
Options outstanding (in shares)	2.7
Options exercisable (in shares)	2.5
Options vested and exercisable and expected to vest (in shares)	2.7	[2]
Options available for grant (in shares)	14.3
Weighted average price per share
Options outstanding (per share)	$33.54
Granted (per share)	$0	[1]
Exercised (per share)	$32.76
Canceled/Forfeited (per share)	$0
Options outstanding (per share)	$34.46
Options exercisable (per share)	$33.72
Options vested and exercisable and expected to vest (per share)	$34.46	[2]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options outstanding, Weighted average contractual term	4 years 2 months 12 days
Options outstanding, Aggregate Intrinsic Value	$53.10	[3]
Options vested and exercisable, Weighted average contractual term	3 years 10 months 24 days
Options vested and exercisable, Aggregate Intrinsic Value	49.9	[3]
Options vested and exercisable and expected to vest, Weighted average remaining contractual term	4 years 2 months 12 days	[2]
Options vested and exercisable and expected to vest, Aggregate Intrinsic Value	$53.10	[2],[3]
[1]	Autodesk did not grant stock options in the twelve months ended January 31, 2015.
[2]	Options expected to vest reflect an estimated forfeiture rate.
[3]	Represents the total pre-tax intrinsic value, based on Autodesk’s closing stock price of $54.01 per share as of January 31, 2015, which would have been received by the option holders had all option holders exercised their options as of that date.

Employee_and_Director_Stock_Pl3

Employee and Director Stock Plans - Intrinsic Value of Options Exercised and Weighted Average Grant Date Fair Value of Stock Options Granted (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Intrinsic value of options exercised	$67.60	[1]	$149	[1]	$90.90	[1]
Weighted average grant date fair value per share of stock options granted	$0	[2]	$0	[2]	$13.40	[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 Black-Scholes Merton ("BSM") option pricing model. For the twelve months ended January 31, 2015 and 2014, Autodesk did not grant stock options.

Employee_and_Director_Stock_Pl4

Employee and Director Stock Plans - Options Outstanding and Exercisable (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jan. 31, 2015		Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Vested and Exercisable, Number of Shares	2.5
Options Vested and Exercisable, Weighted average contractual life (in years)	3 years 10 months 24 days
Options Vested and Exercisable, Weighted average exercise price	$33.72
Options Vested and Exercisable, Aggregate intrinsic value	$49.90	[1]
Options Outstanding, Number of Shares	2.7		5.9
Options Outstanding, Weighted average contractual life (in years)	4 years 2 months 12 days
Options Outstanding, Weighted average exercise price	$34.46		$33.54
Options Outstanding, Aggregate Intrinsic Value	$53.10	[1]
Closing stock price (in dollars per share)	$54.01
$12.31 - $29.49
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of per-share exercise prices, Lower Limit	$12.31
Range of per-share exercise prices, Upper Limit	$29.49
Options Vested and Exercisable, Number of Shares	0.9
Options Vested and Exercisable, Weighted average exercise price	$23.76
Options Outstanding, Number of Shares	0.9
Options Outstanding, Weighted average exercise price	$23.83
$29.50 - $41.62
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of per-share exercise prices, Lower Limit	$29.50
Range of per-share exercise prices, Upper Limit	$41.62
Options Vested and Exercisable, Number of Shares	1.2
Options Vested and Exercisable, Weighted average exercise price	$38.73
Options Outstanding, Number of Shares	1.3
Options Outstanding, Weighted average exercise price	$38.85
$42.39 - $43.81
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of per-share exercise prices, Lower Limit	$42.39
Range of per-share exercise prices, Upper Limit	$43.81
Options Vested and Exercisable, Number of Shares	0.4
Options Vested and Exercisable, Weighted average exercise price	$43.80
Options Outstanding, Number of Shares	0.5
Options Outstanding, Weighted average exercise price	$43.79
[1]	Represents the total pre-tax intrinsic value, based on Autodesk’s closing stock price of $54.01 per share as of January 31, 2015, which would have been received by the option holders had all option holders exercised their options as of that date.

Employee_and_Director_Stock_Pl5

Employee and Director Stock Plans - Summary of Restricted Stock Award and Restricted Stock Unit Activity (Detail) (USD $)	12 Months Ended
	Jan. 31, 2015		Jan. 31, 2014	Jan. 31, 2013
Restricted Stock Units (RSUs) and Performance Stock Units (PSUs)
Unreleased restricted stock
Unreleased restricted stock units at January 31, 2014	6,515,600
Granted	4,481,800
Vested	-2,675,600
Canceled/Forfeited	-445,800
Performance adjustment	-74,700	[1]
Unreleased restricted stock units at January 31, 2015	7,801,300		6,515,600
Weighted average grant date fair value
Unreleased restricted stock units at January 31, 2014	$39.15
Granted	$54.17		$42.37	$33.32
Vested	$37.36
Canceled/Forfeited	$41.43
Performance adjustment	$42.23	[1]
Unreleased restricted stock units at January 31, 2015	$48.46		$39.15
Performance Stock Units (PSUs)
Unreleased restricted stock
Granted	500,000
Unreleased restricted stock units at January 31, 2015	900,000
Weighted average grant date fair value
Equity instruments other than options, percent of target	65.80%		92.30%
[1]	Based on Autodesk's financial results for the performance period, the fiscal 2014 and 2013 performance stock units were earned at 65.8% and 92.3% of the target award, respectively. The vesting of the performance stock units is subject to the holders satisfying the remaining service condition of the awards.

Employee_and_Director_Stock_Pl6

Employee and Director Stock Plans - Stock-Based Compensation Expense - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Jan. 14, 2014	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
		Plan
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Number of Active Stock Plans		2
Number of Expired Plans		3
Number of additional share authorized (in shares)	11,400,000
Shares granted to shares issued (in shares)		2.11
Grants in period, net of forfeitures (in shares)		0	[1]
Shares available for future issuance (in shares)		55,000,000
Total compensation costs related to non-vested options		$0.60
Total compensation costs related to non-vested options, expected to be recognized over a weighted average period (in years)		2 months 12 days
Share based compensation expense, restricted stock units						0
Percentage of compensation that eligible employees can use to purchase common stock, maximum		15.00%
Percentage of fair market value eligible employees can purchase common stock, minimum		85.00%
Shares available for future issuance, increases on the first trading day of each fiscal year (In shares)		10,000,000
Shares available for future issuance, percentage of outstanding shares plus any shares repurchased by Autodesk (as a percent)		2.00%
Weighted average grant date fair value (in dollars per share)		$0	[2]	$0	[2]	$13.40	[2]
Employee Stock Plan 2012
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares of common stock reserved for issuance (in shares)		32,600,000
Restricted stock award, net of forfeitures (in shares)		26,600,000
Shares forfeited (in shares)		6,000,000
Shares granted to shares issued (in shares)		1.79
Shares available for future issuance (in shares)		12,300,000
Vesting period		3 years
Outside directors stock plan 2012
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares of common stock reserved for issuance (in shares)		2,600,000
Shares available for future issuance (in shares)		2,000,000
Outside directors stock plan 2012 | Minimum
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period		1 year
Outside directors stock plan 2012 | Maximum
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting period		3 years
ESP Plan
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Shares available for future issuance (in shares)		40,700,000
Shares issued under the ESP plan (in dollars per share)		2,100,000		2,900,000		2,900,000
Shares issued under the ESP Plan, average price (in dollars per share)		$33.91		$22.61		$21.79
Weighted average grant date fair value (in dollars per share)		$15.14		$11.80		$12.21
Employee Service Share Based Compensation recognized Compensation Costs On Nonvested Restricted Shares		23.9		22.9		34
Stock Options and Restricted Stock | Employee Stock Plan 2012
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Grants in period, net of forfeitures (in shares)		22,100,000
Share based payment award options expiration term (in years)		10 years
Restricted Stock Units (RSUs) and Performance Stock Units (PSUs)
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Granted (in dollars per share)		$54.17		$42.37		$33.32
Fair value of units vested in period		100		73.8		33.6
Restricted stock granted (in shares)		4,481,800
Number of awards granted but unreleased		7,801,300		6,515,600
Restricted Stock Units (RSUs)
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Restricted stock granted (in shares)		4,000,000
Share based compensation expense, restricted stock units		118.9		74.9		70.5
Total compensation cost related to non-vested awards not yet recognized		245
Total compensation cost related to non-vested awards not yet recognized, weighted average period of recognition (in years)		1 year 9 months 29 days
Number of awards granted but unreleased		6,900,000
Restricted Stock Units (RSUs) | Outside directors stock plan 2012
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Grants in period, net of forfeitures (in shares)		600,000
Performance Stock Units (PSUs)
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Restricted stock granted (in shares)		500,000
Share based compensation expense, restricted stock units		17.5		8.7		8.1
Total compensation cost related to non-vested awards not yet recognized		2.5
Total compensation cost related to non-vested awards not yet recognized, weighted average period of recognition (in years)		9 months 14 days
Number of awards granted but unreleased		900,000
Performance Stock Units (PSUs) | Year One
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting percentage (up to percentage)		33.33%
Performance Stock Units (PSUs) | Year Two
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting percentage (up to percentage)		33.33%
Performance Stock Units (PSUs) | Year Three
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Vesting percentage (up to percentage)		33.33%
Goodwill acquired from other acquisitions | Restricted Stock Units (RSUs)
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Share based compensation expense, restricted stock units						$16.60
[1]	Autodesk did not grant stock options in the twelve months ended January 31, 2015.
[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 Black-Scholes Merton ("BSM") option pricing model. For the twelve months ended January 31, 2015 and 2014, Autodesk did not grant stock options.

Employee_and_Director_Stock_Pl7

Employee and Director Stock Plans - Options Outstanding (Details) (USD $)	Jan. 31, 2015		Jan. 31, 2014
In Millions, except Per Share data, unless otherwise specified
Number of securities to be issued upon exercise of outstanding options	10.5
Weighted Average Exercise Price	$34.46		$33.54
Shares available for future issuance	55
Equity Compensation Plans Approved by Security Holders
Number of securities to be issued upon exercise of outstanding options	10.5
Weighted Average Exercise Price	$34.46
Shares available for future issuance	55	[1]
[1]	Included in this amount are 40.7 million securities available for future issuance under Autodesk’s ESP Plan.

Income_Taxes_Provision_for_inc

Income Taxes - Provision for income taxes (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Federal:
Current									($43.80)	$29.10	$30.90
Deferred									-11.9	-41.4	-13.3
State:
Current									-13.2	0.6	7.8
Deferred									9	0	-18.6
Foreign:
Current									69.5	63.9	54.3
Deferred									-8.4	-1.1	1.5
Income tax expense	($18.60)	$0.90	$11.60	$7.30	$2.40	$11.60	$20.10	$17	$1.20	$51.10	$62.60

Income_Taxes_Differences_betwe

- Income Taxes Differences between the U.S. statutory rate and the aggregate income tax provision (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Income Tax Disclosure [Abstract]
Income tax provision at U.S. Federal statutory rate									$29	$98	$108.50
State income tax benefit, net of the U.S. Federal benefit									-4	-2.9	-1.7
Foreign income taxed at rates different from the U.S. statutory rate									-40	-57.1	-54.5
U.S. valuation allowance									2.9	2.1	1.7
Tax effect of non-deductible stock-based compensation									15.7	10.8	21.1
Research and development tax credit benefit									-7.2	-8.8	-7
Tax (benefit) expense from closure of income tax audits and changes in uncertain tax positions									-0.7	3.6	-2.8
Tax effect of officer compensation in excess of $1.0 million									2.4	3	1.8
U.S. Manufacturer's deduction									0	-0.1	-4.9
Other									3.1	2.5	0.4
Income tax expense	($18.60)	$0.90	$11.60	$7.30	$2.40	$11.60	$20.10	$17	$1.20	$51.10	$62.60

Income_Taxes_Components_Of_Def

- Income Taxes Components Of Deferred Tax Assets and Liabilities (Details) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Millions, unless otherwise specified
Income Tax Disclosure [Abstract]
Stock-based compensation	$39.90	$37.40
Research and development tax credit carryforwards	62.6	78.4
Foreign tax credit carryforwards	0	16.3
Accrued compensation and benefits	43.6	38.6
Other accruals not currently deductible for tax	18.4	14.5
Purchased technology and capitalized software	13.2	23.4
Fixed assets	16.2	17.5
Tax loss carryforwards	16	12.6
Deferred Revenue	48	33.1
Other	7.4	5.1
Total deferred tax assets	265.3	276.9
Less: valuation allowance	-70.8	-67.2
Net deferred tax assets	194.5	209.7
Unremitted earnings of foreign subsidiaries	-9.4	-21.8
Total deferred tax liability	-9.4	-21.8
Net deferred tax assets	$185.10	$187.90

Income_Taxes_Unrecognized_Tax_

- Income Taxes Unrecognized Tax Benefits Reconciliation, Table (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits at the beginning of the fiscal year	$222.10	$212.70	$201.10
Increases for tax positions of prior years	3.2	1.8	0.4
Decreases for tax positions of prior years	-2.5	-0.3	-0.4
Increases for tax positions related to the current year	33.2	15.3	17.8
Decreases relating to settlements with taxing authorities	-5.4	-4.6	-3
Reductions as a result of lapse of the statute of limitations	-4.8	-2.8	-3.2
Gross unrecognized tax benefits at the end of the fiscal year	$245.80	$222.10	$212.70

Income_Taxes_Additional_Inform

- Income Taxes Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Income Taxes [Line Items]
Increase Decrease In Income taxes Payable Current	$0.50
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits	217.9
Income (Loss) from Continuing Operations before Income Taxes, Foreign	302.5	380.5	383.3
Valuation Allowance, Deferred Tax Asset, Change in Amount	3.6	15.9	3.8
Deferred Tax Liability Not Recognized, Cumulative Amount of Temporary Difference	1,809.40
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability	514.4
Net deferred tax assets	185.1	187.9
Foreign Income Tax Expense (Benefit), Continuing Operations	1.2	9.7	6.6
Income Tax Holiday, Income Tax Benefits Per Share	$0.01	$0.04	$0.03
Current Foreign Tax Expense (Benefit)	69.5	63.9	54.3
Gross unrecognized tax benefits	245.8	222.1	212.7	201.1
Amount of gross unrecognized tax benefits that would impact the effective tax rate, if recognized	227.3
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	2	2.8	1.9
Domestic Country
Income Taxes [Line Items]
Operating Loss Carryforwards	21.7
State and Local Jurisdiction
Income Taxes [Line Items]
Operating Loss Carryforwards	354.3
State and Local Jurisdiction and the Internal Revenue Service
Income Taxes [Line Items]
Deferred Tax Assets, Capital Loss Carryforwards	9.2
Research
Income Taxes [Line Items]
Tax Credit Carryforward, Amount	104.7
California State Research
Income Taxes [Line Items]
Tax Credit Carryforward, Amount	54.8
Canadian
Income Taxes [Line Items]
Tax Credit Carryforward, Amount	59.8
Foreign Country
Income Taxes [Line Items]
Operating Loss Carryforwards	7.4
Tax Credit Carryforward, Amount	$163.60

Acquisitions_Summary_of_Fair_V

Acquisitions - Summary of Fair Value of Assets Acquired and Liabilities Assumed by Major Class (Detail) (USD $)	0 Months Ended		12 Months Ended		0 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	29-May-14	Jan. 31, 2015	Jan. 31, 2014	Nov. 21, 2013	Jan. 31, 2013	Feb. 06, 2014
Business Acquisition [Line Items]
Goodwill			$1,456.20	$1,009.90		$871.50
Shotgun Software Inc.
Business Acquisition [Line Items]
Goodwill			43.2
Deferred Revenue			-0.7
Deferred tax (liability) asset			-2.6
Net tangible assets			0.1
Total			54.5
Payments to acquire business	51.2
Shotgun Software Inc. | Developed technologies
Business Acquisition [Line Items]
Intangible assets			5.4
Shotgun Software Inc. | Customer relationships
Business Acquisition [Line Items]
Intangible assets			7.5
Shotgun Software Inc. | Trade name
Business Acquisition [Line Items]
Intangible assets			1.6
Within Technologies Limited
Business Acquisition [Line Items]
Goodwill		78.9	80.6
Deferred Revenue			0
Deferred tax (liability) asset			-1.7
Net tangible assets			-0.3
Total			88
Payments to acquire business		88
Within Technologies Limited | Developed technologies
Business Acquisition [Line Items]
Intangible assets			4.6
Within Technologies Limited | Customer relationships
Business Acquisition [Line Items]
Intangible assets			3.6
Within Technologies Limited | Trade name
Business Acquisition [Line Items]
Intangible assets			1.2
Delcam plc
Business Acquisition [Line Items]
Goodwill			190.4				166
Deferred Revenue			-10.4
Deferred tax (liability) asset			-13.2
Net tangible assets			32.7
Total			284.6
Delcam plc | Developed technologies
Business Acquisition [Line Items]
Intangible assets			28.9
Delcam plc | Customer relationships
Business Acquisition [Line Items]
Intangible assets			39.7
Delcam plc | Trade name
Business Acquisition [Line Items]
Intangible assets			16.5
Other
Business Acquisition [Line Items]
Goodwill			180.6	67
Deferred Revenue			-0.4
Deferred tax (liability) asset			-2.1	0.7
Net tangible assets			1.3	1.5
Total				89.7
Payments to acquire business			234.5	89.7
Other | Developed technologies
Business Acquisition [Line Items]
Intangible assets			39	15.9
Other | Customer relationships
Business Acquisition [Line Items]
Intangible assets			9.8	2.8
Other | Trade name
Business Acquisition [Line Items]
Intangible assets			6.3	1.8
Graitec SA
Business Acquisition [Line Items]
Goodwill				73.4	64.1
Deferred tax (liability) asset				-6.2
Net tangible assets				0
Total				87
Payments to acquire business					87
Graitec SA | Developed technologies
Business Acquisition [Line Items]
Intangible assets				15.9
Graitec SA | Customer relationships
Business Acquisition [Line Items]
Intangible assets				2.2
Graitec SA | Trade name
Business Acquisition [Line Items]
Intangible assets				$1.70

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Details) (USD $)	0 Months Ended				12 Months Ended
In Millions, unless otherwise specified	Jun. 27, 2014	29-May-14	Feb. 06, 2014	Nov. 21, 2013	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
					Entity	Entity
Business Acquisition [Line Items]
Goodwill					$1,456.20	$1,009.90	$871.50
Shotgun Software Inc.
Business Acquisition [Line Items]
Consideration transferred	54.5
Payments to acquire business	51.2
Fair value of original convertible debt investment	3.3
Goodwill					43.2
Within Technologies Limited
Business Acquisition [Line Items]
Payments to acquire business		88
Goodwill		78.9			80.6
Delcam plc
Business Acquisition [Line Items]
Consideration transferred			284.6
Goodwill			166		190.4
Graitec SA
Business Acquisition [Line Items]
Payments to acquire business				87
Goodwill				64.1		73.4
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Payments to acquire business					234.5	89.7
Goodwill					$180.60	$67
Number of Businesses Acquired					21	14

Deferred_Compensation_Addition

Deferred Compensation - Additional Information (Detail) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Millions, unless otherwise specified
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Marketable securities	$888.80
Rabbi Trust
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation liability current	5.3	1.9
Deferred compensation liability non-current	35	37
Marketable Securities, Current
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Trading securities	40.3	38.9
Marketable Securities, Current | Rabbi Trust
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Trading securities	$40.30	$38.90

Borrowing_Arrangements_Detail

Borrowing Arrangements (Detail) (USD $)	12 Months Ended	1 Months Ended
	Jan. 31, 2015	Dec. 31, 2012	Jan. 31, 2014
Debt Disclosure [Line Items]
Unsecured revolving credit facility	$400,000,000
Unsecured revolving credit facility, option to request an increase in the amount of the credit facility up to	100,000,000
Line of credit facility, expiration	31-May-18
Line of credit facility, outstanding borrowings	0		0
Senior Notes | Senior Notes 2017
Debt Disclosure [Line Items]
Face Amount		400,000,000
Stated interest rate		1.95%
Maturity Date		15-Dec-17
Senior Notes | Senior Notes 2022
Debt Disclosure [Line Items]
Face Amount		350,000,000
Stated interest rate		3.60%
Maturity Date		15-Dec-22
Senior Notes | Senior Notes
Debt Disclosure [Line Items]
Proceeds from Debt, Net of Issuance Costs		739,300,000
Unamortized Discount		4,500,000
Debt Issuance Cost		6,100,000
Debt redemption percentage of principle amount (as a percent)		101.00%
Fair Value Disclosure	$759,900,000

Commitments_and_Contingencies_1

Commitments and Contingencies - Future Minimum Lease Payments (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Future Minimum Lease Payments [Abstract]
2016	$55.40
2017	47.3
2018	40.7
2019	29.1
2020	19.5
Thereafter	32.6
Future minimum lease payments required	224.6
Less: Sublease income	1.9
Future minimum lease payments required, net	222.7
Rent expense	$55	$50.20	$56.10

Commitments_and_Contingencies_2

Commitments and Contingencies - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Total non cancellable purchase commitments	$85.40
Total non-cancellable purchase commitments, term	for periods through fiscal 2020
Royalty expense recorded under cost of license and other revenue	$17.90	$18	$16.40

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Stockholders Equity Note [Line Items]
Preferred stock, shares authorized	2	2
Common Stock Repurchase Program
Stockholders Equity Note [Line Items]
Repurchase and retirement of common shares (in shares)	6.9	10.5	12.5
Average repurchase price per share (usd per share)	$53.83	$40.43	$34.50
Common Stock shares remained available for repurchase under repurchase plans	14.8

Interest_And_Other_Income_net_1

Interest And Other Income, net (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Interest and Other Income, net [Abstract]
Interest and investment (expense) income, net	($13.20)	($9.80)	$4.90
(Loss) gain on foreign currency	-3.9	4	1.2
Loss on strategic investments	-23.3	-1.8	-4
Other income	2.7	2.7	2
Interest and other (expense) income, net	($37.70)	($4.90)	$4.10

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014		Jan. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net gain on derivative instruments	$3.50	$2.80
Net unrealized gain on available-for-sale securities	1.8	2.9
Defined benefit pension items	-7.7	-13.1
Foreign currency translation adjustments	1.8	1.7
Accumulated other comprehensive loss	-0.6	-5.7
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	47	11.1
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments and Tax	-1.7	-0.2
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments and Tax	-18.3	3.9
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax	-80.7	-2
Other Comprehensive Income (Loss), before Reclassifications, before Tax	-53.7	12.8	[1]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	-7	-11.5
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI for Write-down of Securities, before Tax	1.7	-1.2
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	0.5	0.9
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0	0
Pre-tax reclassifications from Accumulated other comprehensive (loss)	-4.8	-11.8	[1]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	-0.7	1.1
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI for Write-down of Securities, Tax	-0.2	0.3
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax	1.8	0.6
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	4.9	2.1
Other Comprehensive Income (Loss), Tax	5.8	4.1	[1]
Net gain (loss) on derivative instruments (net of tax effect of ($0.7), $1.1, and ($0.5))	39.3	0.7		-6.4
Change in net unrealized gain (loss) on available-for-sale securities (net of tax effect of ($0.2), $0.3, and ($0.6))	-0.2	-1.1		2
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	16	-5.4		6.1
Net change in cumulative foreign currency translation (loss) gain (net of tax effect of $4.9, $2.1, and $2.1)	-75.8	0.1		-1.1
Other comprehensive income (loss)	-52.7	5.1		-11.6
Net gain on derivative instruments	42.8	3.5		2.8
Net unrealized gain on available-for-sale securities	1.6	1.8		2.9
Defined benefit pension items	-23.7	-7.7		-13.1
Foreign currency translation adjustments	-74	1.8		1.7
Accumulated other comprehensive loss	($53.30)	($0.60)		($5.70)
[1]	For comparability, the presentation of prior period balances were adjusted to align with current year presentation.

Net_Income_Per_Share_Computati

Net Income Per Share - Computation of Net Income Per Share Amounts (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Numerator:
Net income	$11.50	$10.70	$31.30	$28.30	$53.90	$57.60	$61.70	$55.60	$81.80	$228.80	$247.40
Denominator:
Denominator for basic net income per share—weighted average shares									227.1	224	226.4
Effect of dilutive securities									5.3	5.6	5.3
Denominator for dilutive net income per share									232.4	229.6	231.7
Basic net income per share (usd per share)	$0.05	$0.05	$0.14	$0.12	$0.24	$0.26	$0.28	$0.25	$0.36	$1.02	$1.09
Diluted net income per share (usd per share)	$0.05	$0.05	$0.13	$0.12	$0.23	$0.25	$0.27	$0.24	$0.35	$1	$1.07

Net_Income_Per_Share_Additiona

Net Income Per Share - Additional Information (Detail)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Earnings Per Share [Abstract]
Potentially dilutive shares excluded from the computation of diluted net income per share	0.1	5.4	9.6

Segments_Concerning_the_Operat

Segments - Concerning the Operations Of Reportable Segments (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
Segment Reporting Information [Line Items]
Net revenue	$664.60	$618	$637.10	$592.50	$586.60	$555.20	$561.70	$570.40	$2,512.20		$2,273.90		$2,312.20
Gross profit	575.1	532	549.2	513.8	514.7	488.1	493.9	502.9	2,170.10		1,999.60		2,073.70
Depreciation and Amortization									145.9		128.9		127.8
Architecture, Engineering, and Construction
Segment Reporting Information [Line Items]
Net revenue									872.6	[1]	730.6	[1]	701.1	[1]
Gross profit									785.8	[1]	663.8	[1]	642	[1]
Depreciation and Amortization									1.3		0.2		0.2
Platform Solutions and Emerging Business
Segment Reporting Information [Line Items]
Net revenue									796.7	[1]	789.2	[1]	843	[1]
Gross profit									712.3	[1]	716.8	[1]	788.8	[1]
Depreciation and Amortization									6.8		5.5		1.8
Manufacturing
Segment Reporting Information [Line Items]
Net revenue									675.6		579.4		573.8
Gross profit									604		531.5		531.3
Depreciation and Amortization									3		0.9		0.5
Media and Entertainment
Segment Reporting Information [Line Items]
Net revenue									167.3	[1]	174.7	[1]	194.3	[1]
Gross profit									127.3		137.8		156.5
Depreciation and Amortization									0.3		0.2		0.4
Unallocated
Segment Reporting Information [Line Items]
Gross profit									-59.3	[2]	-50.3	[2]	-44.9	[2]
Depreciation and Amortization									$134.50		$122.10		$124.90
[1]	Prior period segment revenue amounts have been updated to conform to the current period's presentation.
[2]	Unallocated amounts primarily relate to corporate expenses and other costs and expenses that are managed outside the reportable segments, including stock-based compensation expense.

Segments_Operations_by_geograp

Segments - Operations by geographic area (Details) (USD $)	3 Months Ended										12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015		Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014		Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
Segment Reporting Information [Line Items]
Net revenue	$664.60		$618	$637.10	$592.50	$586.60		$555.20	$561.70	$570.40	$2,512.20		$2,273.90		$2,312.20
Total long-lived assets	159.2	[1]				130.3	[1]				159.2	[1]	130.3	[1]
Americas
Segment Reporting Information [Line Items]
Net revenue											898		818.9		836.2
Total long-lived assets	111.9	[1]				91.9	[1]				111.9	[1]	91.9	[1]
Americas | U.S.
Segment Reporting Information [Line Items]
Net revenue											736.4		672.3		672.1
Total long-lived assets	108.8	[1]				89	[1]				108.8	[1]	89	[1]
Americas | Other Americas
Segment Reporting Information [Line Items]
Net revenue											161.6		146.6		164.1
Total long-lived assets	3.1	[1]				2.9	[1]				3.1	[1]	2.9	[1]
Europe Middle East And Africa [Member]
Segment Reporting Information [Line Items]
Net revenue											980		851.8		868.5
Europe, Middle East, and Africa | Europe Middle East And Africa [Member]
Segment Reporting Information [Line Items]
Total long-lived assets	25	[1]				27.2	[1]				25	[1]	27.2	[1]
Asia Pacific
Segment Reporting Information [Line Items]
Net revenue											634.2		603.2		607.5
Total long-lived assets	22.3	[1]				11.2	[1]				22.3	[1]	11.2	[1]
Asia Pacific | Japan
Segment Reporting Information [Line Items]
Net revenue											269		274.5		278.3
Asia Pacific | Other Asia Pacific
Segment Reporting Information [Line Items]
Net revenue											$365.20		$328.70		$329.20
[1]	Long-lived assets exclude deferred tax assets, marketable securities, goodwill, and other intangible assets. Prior period amounts have been updated to conform to the current period's presentation.

Retirement_Benefit_Plans_Addit

Retirement Benefit Plans - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Funded percentage	72.00%
Accumulated benefit obligation	$124.30	$45.30
Actual plan asset allocations	42.00%	99.00%
Estimated future employer contributions in next fiscal year	4.6
Expected long-term rate of return on plan assets	3.90%	1.90%	2.00%
United States Pension Plan of US Entity
Defined Contribution Plan Disclosure [Line Items]
Maximum annual contributions per employee	50.00%
Cost Recognized	11.2	8.1	7.9
Foreign Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Contributions paid by employer	$23.50	$22.30	21.5

Retirement_Benefit_Plans_Funde

Retirement Benefit Plans - Funded Status (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning projected benefit obligation	$62.20	$61.50
Service cost	4.6	5.4	4.5
Interest cost	3.9	1.1	1.3
Actuarial loss (gain)	18.8	-3.2
Benefits paid	-7.5	-5.9
Foreign currency exchange rate changes	-1.2	0.8
Curtailments and settlements	-2.9	0
Contributions by plan participants	5.9	2.5
Business combinations	60.9	0
Ending projected benefit obligation	144.7	62.2	61.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning fair value of plan assets	40.7	37.5
Actual return on plan assets	4.1	0.9
Contributions paid by employer	4.9	5.2
Contributions paid by plan participants	5.9	2.5
Benefit payments	-7.5	-5.9
Curtailments and settlements	-2.9	0
Foreign currency exchange rate changes	-1.2	0.5
Business combinations	60.2	0
Ending fair value of plan assets	104.2	40.7	37.5
Funded status	($40.50)	($21.50)

Retirement_Benefit_Plans_Balan

Retirement Benefit Plans - Balance Sheet (Details) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]
Amounts Recognized in Balance Sheet	$67.10	$30.20
Other long-term liabilities
Defined Benefit Plan Disclosure [Line Items]
Amounts Recognized in Balance Sheet	40.5	21.5
Accumulated other comprehensive loss, before tax
Defined Benefit Plan Disclosure [Line Items]
Amounts Recognized in Balance Sheet	$26.60	$8.70

Retirement_Benefit_Plans_Plan_

Retirement Benefit Plans - Plan Assets (Details) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Millions, unless otherwise specified
Plans with accumulated benefit obligations in excess of plan assets:
Accumulated benefit obligations	$124	$45.30
Plan Assets	103.9	40.7
Plans with projected benefit obligations in excess of plan assets:
Projected benefit obligations	144.7	62.2
Plan Assets	$104.20	$40.70

Retirement_Benefit_Plans_Alloc

Retirement Benefit Plans - Allocation of Plan Assets (Details) (USD $)	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
In Millions, unless otherwise specified
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	$104.20	$40.70	$37.50
Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	55.8
Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	48.4
Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	0
Investment fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	60.6	0
Investment fund | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	55.7
Investment fund | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	4.9
Investment fund | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	0
Insurance contracts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	43.5	40.2
Insurance contracts | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	0
Insurance contracts | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	43.5
Insurance contracts | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	0
Investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	104.1	40.2
Investments | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	55.7
Investments | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	48.4
Investments | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	0
Cash
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	0.1	0.5
Cash | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	0.1
Cash | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	0
Cash | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Value of Plan Assets	$0

Retirement_Benefit_Plans_Estim

Retirement Benefit Plans - Estimated Payments (Details) (USD $)	Jan. 31, 2015
In Millions, unless otherwise specified
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2016	$3.50
2017	3.4
2018	3.5
2019	3.3
2020	3.1
2021-2025	$17.50

Retirement_Benefit_Plans_Net_P

Retirement Benefit Plans - Net Periodic Benefit Cost (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Service cost for benefits earned during the period	$4.60	$5.40	$4.50
Interest cost on projected benefit obligation	3.9	1.1	1.3
Expected return on plan assets	-4.6	-0.8	-0.8
Amortization of prior service credit	-0.1	-0.1	-0.1
Amortization of loss	0.6	1	0.7
Net periodic benefit cost	$4.40	$6.60	$5.60

Retirement_Benefit_Plans_Other

Retirement Benefit Plans - Other Comprehensive Income (Loss) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent [Abstract]
Net loss (gain) for period	$18.40	($3.90)	$6.30
Amortization of prior service credit	0.1	0.1	0.1
Amortization of net loss	-0.6	-1	-0.7
Other comprehensive loss (income)	$17.90	($4.80)	$5.70

Retirement_Benefit_Plans_Accum

Retirement Benefit Plans - Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	Jan. 31, 2015	Jan. 31, 2014
In Millions, unless otherwise specified
Compensation and Retirement Disclosure [Abstract]
Net prior service credit	($1.80)	($1.90)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	-28.4	-10.6
Accumulated other comprehensive loss, before tax	$26.60	$8.70

Retirement_Benefit_Plans_AOCI_

Retirement Benefit Plans - AOCI Next Fiscal Year (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year [Abstract]
Amortization of prior service credit	$0.10
Amortization of the net loss	-1.5
Total amortization	($1.40)

Retirement_Benefit_Plans_Benef

Retirement Benefit Plans - Benefit Cost Assumptions (Details)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Discount rate	3.30%	2.30%	1.80%
Expected long-term rate of return on plan assets	3.90%	1.90%	2.00%
Rate of compensation increase	2.20%	2.20%	2.10%

Retirement_Benefit_Plans_Benef1

Retirement Benefit Plans - Benefit Obligation Assumptions (Details)	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Discount rate	2.40%	2.20%	1.80%
Rate of compensation increase	1.20%	2.20%	2.00%

Restructuring_Reserves_Details

Restructuring Reserves (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
Restructuring Cost and Reserve [Line Items]
Additions	$3.10		$12.80
Restructuring Reserve [Roll Forward]
Beginning Balance	5.1		7.3
Additions	3.1		12.8
Payments	-6.8		-14.9
Adjustments	0.2	[1]	-0.1	[1]
Ending Balance	1.6		5.1
Current portion	0.7	[2]	4	[2]
Non-current portion	0.9	[2]	1.1	[2]
Total	1.6		5.1
Fiscal 2013 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs incurred to date			46.2
Restructuring Reserve [Roll Forward]
Beginning Balance					7.3
Ending Balance					7.3
Current portion					5.8	[3]
Non-current portion					1.5	[3]
Total					7.3
Fiscal 2014 Plan
Restructuring Cost and Reserve [Line Items]
Additions	15
Restructuring Reserve [Roll Forward]
Additions	15
One-time Termination Benefits | Fiscal 2013 Plan
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated			500
One-time Termination Benefits | Fiscal 2014 Plan
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated	85
Facility Closing | Fiscal 2013 Plan
Restructuring Cost and Reserve [Line Items]
Number of facilities consolidated			8
Facility Closing | Fiscal 2014 Plan
Restructuring Cost and Reserve [Line Items]
Number of facilities consolidated	4
Employee Severance | Fiscal 2013 Plan
Restructuring Cost and Reserve [Line Items]
Additions	0		0.8
Restructuring Reserve [Roll Forward]
Beginning Balance	0.1		4.5
Additions	0		0.8
Payments	0		-5
Adjustments	-0.1	[1]	-0.2	[1]
Ending Balance	0		0.1
Total	0		0.1
Employee Severance | Fiscal 2014 Plan
Restructuring Cost and Reserve [Line Items]
Additions	2.5		9.4
Restructuring Reserve [Roll Forward]
Beginning Balance	3.5		0
Additions	2.5		9.4
Payments	-6		-5.7
Adjustments	0	[1]	-0.2	[1]
Ending Balance	0		3.5
Total	0		3.5
Lease Termination | Fiscal 2013 Plan
Restructuring Cost and Reserve [Line Items]
Additions	0.3		1.5
Restructuring Reserve [Roll Forward]
Beginning Balance	0.2		2.8
Additions	0.3		1.5
Payments	-0.3		-4.2
Adjustments		[1]	0.1	[1]
Ending Balance	0.2		0.2
Total	0.2		0.2
Lease Termination | Fiscal 2014 Plan
Restructuring Cost and Reserve [Line Items]
Additions	0.3		1.1
Restructuring Reserve [Roll Forward]
Beginning Balance	1.3		0
Additions	0.3		1.1
Payments	-0.5
Adjustments	0.3	[1]	0.2	[1]
Ending Balance	1.4		1.3
Total	$1.40		$1.30
[1]	Adjustments include the impact of foreign currency translation.
[2]	The current and non-current portions of the reserve are recorded in the Consolidated Balance Sheets under “Other accrued liabilities” and “Other liabilities,” respectively
[3]	The current and non-current portions of the reserve are recorded in the Consolidated Balance Sheets under “Other accrued liabilities” and “Other liabilities,” respectively.

Selected_Quarterly_Financial_I2

Selected Quarterly Financial Information (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Net revenue	$664.60	$618	$637.10	$592.50	$586.60	$555.20	$561.70	$570.40	$2,512.20	$2,273.90	$2,312.20
Gross profit	575.1	532	549.2	513.8	514.7	488.1	493.9	502.9	2,170.10	1,999.60	2,073.70
Income from operations	14	14.6	49.9	42.2	51.7	68.1	83.6	81.4	120.7	284.8	305.9
Provision for income taxes	18.6	-0.9	-11.6	-7.3	-2.4	-11.6	-20.1	-17	-1.2	-51.1	-62.6
Net income	11.5	10.7	31.3	28.3	53.9	57.6	61.7	55.6	81.8	228.8	247.4
Basic net income per share	$0.05	$0.05	$0.14	$0.12	$0.24	$0.26	$0.28	$0.25	$0.36	$1.02	$1.09
Diluted net income per share	$0.05	$0.05	$0.13	$0.12	$0.23	$0.25	$0.27	$0.24	$0.35	$1	$1.07
Income from operations includes following items [Abstract]
Stock-based compensation expense	49.1	43.1	39.8	33.6	36.1	31.6	31	33.5	165.6	132.2	156.3
Amortization of acquisition related intangibles	21.9	22.6	24.6	23.9	20.6	18.2	20.3	21.6	93	80.7
Additions	$0	$0	$0.80	$2.30	$6.30	$4.40	$1.70	$0.40	$3.10	$12.80	$43.90

FINANCIAL_STATEMENT_SCHEDULE_I1

FINANCIAL STATEMENT SCHEDULE II (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2015		Jan. 31, 2014		Jan. 31, 2013
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year	$4.90		$5.60		$5.50
Valuation Allowances and Reserves, Charged to Cost and Expense	1.6		1.3		1.5
Deductions and Write-Offs	0.2		2		1.4
Balance at End of Year	6.3		4.9		5.6
Product returns reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year	4		4.9		5.8
Valuation Allowances and Reserves, Charged to Cost and Expense	17.4		23.1		25.8
Deductions and Write-Offs	18.8		24		26.7
Balance at End of Year	2.6		4		4.9
Partner Program reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year	38.4	[1]	48.3	[1]	36.5	[1]
Valuation Allowances and Reserves, Charged to Cost and Expense	237.3	[1]	278.6	[1]	286.9	[1]
Deductions and Write-Offs	239.2	[1]	288.5	[1]	275.1	[1]
Balance at End of Year	36.5	[1]	38.4	[1]	48.3	[1]
Restructuring
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year	5.6		8.9		2.4
Valuation Allowances and Reserves, Charged to Cost and Expense	3.2		12.8		45.1
Deductions and Write-Offs	7.2		16.1		38.6
Balance at End of Year	$1.60		$5.60		$8.90
[1]	The partner program reserves balance impacts "Accounts receivable, net" and "Accounts payable" on the accompanying Consolidated Balance Sheets.