ANSYS (ANSS) 10-K 27 Feb 14 2013 Q4 Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 20, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-K	'
Amendment Flag	'false	'
Document Period End Date	31-Dec-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q4	'
Trading Symbol	'ANSS	'
Entity Registrant Name	'ANSYS INC	'
Entity Central Index Key	'0001013462	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	92,539,594
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Entity Public Float	$5,510,000,000	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$742,486	$576,703
Short-term investments	500	452
Accounts receivable, less allowance for doubtful accounts of $5,700 and $4,800, respectively	97,845	96,598
Other receivables and current assets	200,734	216,268
Deferred income taxes	26,031	23,338
Total current assets	1,067,596	913,359
Property and equipment, net	60,538	52,253
Construction In Progress Leased Facility	18,136	0
Goodwill	1,255,704	1,251,247
Other intangible assets, net	291,390	351,173
Other long-term assets	10,586	24,393
Deferred income taxes	18,432	14,992
Total assets	2,722,382	2,607,417
Current liabilities:	'	'
Current portion of long-term debt and capital lease obligations	0	53,149
Accounts payable	7,939	4,924
Accrued bonuses and commissions	43,992	42,601
Accrued income taxes	9,333	8,182
Deferred income taxes	49	1,409
Other accrued expenses and liabilities	69,343	61,329
Deferred revenue	309,775	305,793
Total current liabilities	440,431	477,387
Long-term liabilities:	'	'
Non-Cash Obligation For Construction In Progress Leased Facility	18,136	0
Deferred income taxes	66,899	92,822
Other long-term liabilities	60,670	96,917
Total long-term liabilities	145,705	189,739
Commitments and contingencies	'	'
Stockholders’ equity:	'	'
Preferred stock, $.01 par value; 2,000,000 shares authorized; zero shares issued or outstanding	0	0
Common stock, $.01 par value; 300,000,000 shares authorized; 93,236,023 and 93,201,905 shares issued, respectively	932	932
Additional paid-in capital	926,031	927,368
Retained earnings	1,284,818	1,039,491
Treasury stock, at cost: 917,937 and 536,231 shares, respectively	-72,891	-36,151
Accumulated other comprehensive income	-2,644	8,651
Total stockholders’ equity	2,136,246	1,940,291
Total liabilities and stockholders’ equity	$2,722,382	$2,607,417

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenue:	'	'	'
Software licenses	$528,944	$501,870	$425,881
Maintenance and service	332,316	296,148	265,568
Total revenue	861,260	798,018	691,449
Cost of sales:	'	'	'
Software licenses	28,363	24,512	15,884
Amortization	38,298	40,889	33,728
Maintenance and service	80,031	74,115	69,402
Total cost of sales	146,692	139,516	119,014
Gross profit	714,568	658,502	572,435
Operating expenses:	'	'	'
Selling, general and administrative	218,907	205,178	180,357
Research and development	151,439	132,628	108,530
Amortization	22,359	26,443	17,989
Total operating expenses	392,705	364,249	306,876
Operating income	321,863	294,253	265,559
Interest expense	-1,169	-2,661	-3,332
Interest income	2,841	3,360	3,000
Other expense, net	-1,046	-1,405	-369
Income before income tax provision	322,489	293,547	264,858
Income tax provision	77,162	90,064	84,183
Net income	$245,327	$203,483	$180,675
Earnings per share – basic:	'	'	'
Basic earnings per share (in USD per share)	$2.65	$2.20	$1.96
Weighted average shares - basic	92,691	92,622	92,120
Earnings per share – diluted:	'	'	'
Diluted earnings per share (in USD per share)	$2.58	$2.14	$1.91
Weighted average shares - diluted	95,139	94,954	94,381

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Allowance for doubtful accounts	$5,700	$4,800
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	300,000,000	300,000,000
Common stock, shares issued	93,236,023	93,201,905
Common stock, shares outstanding	0	0
Treasury stock, shares	917,937	536,231
Commitments and contingencies	'	'

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]	'	'	'
Net income	$245,327	$203,483	$180,675
Other comprehensive loss:	'	'	'
Foreign currency translation adjustments	-11,295	-3,225	-5,086
Comprehensive income	$234,032	$200,258	$175,589

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:	'	'	'
Net income	$245,327	$203,483	$180,675
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Depreciation and amortization	80,701	85,422	65,955
Deferred income tax benefit	-24,025	-18,896	-3,021
Provision for bad debts	1,465	938	404
Stock-based compensation expense	35,298	32,415	23,088
Excess tax benefits from stock options	-9,971	-13,888	-10,046
Other	73	69	180
Changes in operating assets and liabilities:	'	'	'
Accounts receivable	-2,983	-12,401	-8,086
Other receivables and current assets	-44,162	-50,485	-16,926
Other long-term assets	-462	5,027	-1,390
Accounts payable, accrued expenses and current liabilities	15,737	9,548	18,222
Accrued income taxes	11,876	14,616	9,668
Deferred revenue	42,105	47,748	49,973
Other long-term liabilities	-17,996	-5,181	-1,035
Net cash provided by operating activities	332,983	298,415	307,661
Cash flows from investing activities:	'	'	'
Acquisitions, net of cash acquired	-4,224	-45,075	-269,486
Capital expenditures	-28,848	-23,977	-22,063
Purchases of short-term investments	-261	-228	-351
Maturities of short-term investments	156	324	257
Net cash used in investing activities	-33,177	-68,956	-291,643
Cash flows from financing activities:	'	'	'
Principal payments on long-term debt	-53,149	-74,408	-31,889
Principal payments on capital leases	0	-14	-87
Purchase of treasury stock	-116,132	-95,477	-12,704
Restricted stock withholding taxes paid in lieu of issued shares	-4,269	0	0
Contingent consideration payments	-3,174	-3,241	0
Proceeds from issuance of common stock under Employee Stock Purchase Plan	2,987	2,446	2,167
Proceeds from exercise of stock options	34,007	31,960	22,791
Excess tax benefits from stock options	9,971	13,888	10,046
Net cash used in financing activities	-129,759	-124,846	-9,676
Effect of exchange rate fluctuations on cash and cash equivalents	-4,264	262	-6,993
Net increase (decrease) in cash and cash equivalents	165,783	104,875	-651
Cash and cash equivalents, beginning of period	576,703	471,828	472,479
Cash and cash equivalents, end of period	742,486	576,703	471,828
Supplemental disclosures of cash flow information:	'	'	'
Income taxes paid	97,706	103,196	64,731
Interest paid	736	1,970	1,858
Construction in progress - leased facility	$18,136	$0	$0

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
In Thousands, except Share data
Balance at Dec. 31, 2010	$1,529,929	$916	$856,718	$655,333	$0	$16,962
Balance, shares at Dec. 31, 2010	'	91,647,000	'	'	0	'
Treasury shares acquired	-12,704	'	'	'	-12,704	'
Treasury shares acquired, shares	'	'	'	'	247,000	'
Stock-based compensation awards issued in Apache acquisition	3,170	'	3,170	'	'	'
Stock-based compensation activity, including tax benefit	56,322	10	43,608	'	12,704	'
Stock-based compensation activity, including tax benefit, shares	'	955,000	'	'	-247,000	'
Issuance of common stock under Employee Stock Purchase Plan	2,167	1	2,166	'	'	'
Issuance of common stock under Employee Stock Purchase Plan, shares	'	50,000	'	'	'	'
Other comprehensive gain (loss)	-5,086	'	'	'	'	-5,086
Net income for the year	180,675	'	'	180,675	'	'
Balance at Dec. 31, 2011	1,754,473	927	905,662	836,008	0	11,876
Balance, shares at Dec. 31, 2011	'	92,652,000	'	'	0	'
Treasury shares acquired	-95,477	'	'	'	95,477	'
Treasury shares acquired, shares	1,500,000	'	'	'	1,500,000	'
Stock-based compensation activity, including tax benefit	78,591	5	20,791	'	57,795	'
Stock-based compensation activity, including tax benefit, shares	'	525,000	'	'	-939,000	'
Issuance of common stock under Employee Stock Purchase Plan	2,446	'	915	'	1,531	'
Issuance of common stock under Employee Stock Purchase Plan, shares	'	25,000	'	'	-25,000	'
Other comprehensive gain (loss)	-3,225	'	'	'	'	-3,225
Net income for the year	203,483	'	'	203,483	'	'
Balance at Dec. 31, 2012	1,940,291	932	927,368	1,039,491	-36,151	8,651
Balance, shares at Dec. 31, 2012	'	93,202,000	'	'	536,000	'
Treasury shares acquired	-116,132	'	'	'	-116,132	'
Treasury shares acquired, shares	1,500,000	'	'	'	1,494,000	'
Stock-based compensation activity, including tax benefit	75,068	'	-806	'	75,874	'
Stock-based compensation activity, including tax benefit, shares	'	34,000	'	'	-1,063,000	'
Issuance of common stock under Employee Stock Purchase Plan	2,987	'	-531	'	3,518	'
Issuance of common stock under Employee Stock Purchase Plan, shares	'	'	'	'	-49,000	'
Other comprehensive gain (loss)	-11,295	'	'	'	'	-11,295
Net income for the year	245,327	'	'	245,327	'	'
Balance at Dec. 31, 2013	$2,136,246	$932	$926,031	$1,284,818	($72,891)	($2,644)
Balance, shares at Dec. 31, 2013	'	93,236,000	'	'	918,000	'

CONSOLIDATED_STATEMENTS_OF_STO1

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (PARENTHETICAL) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2010
Statement of Stockholders' Equity [Abstract]	'	'	'
Stock-based compensation activity, tax benefit	$10,033	$14,216	$9,984

Organization

Organization	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization	'
	Organization
	ANSYS, Inc. (hereafter the "Company" or "ANSYS") develops and globally markets engineering simulation software and technologies widely used by engineers, designers, researchers and students across a broad spectrum of industries and academia, including aerospace, automotive, manufacturing, electronics, biomedical, energy and defense.
	As defined by the accounting guidance, the Company operates as two segments. However, the Company determined that its two operating segments are sufficiently similar and should be aggregated under the criteria provided in the related accounting guidance.
	Given the integrated approach to the multi-discipline problem-solving needs of the Company’s customers, a single sale of software may contain components from multiple product areas and include combined technologies. The Company also has a multi-year product and integration strategy that will result in new, combined products or changes to the historical product offerings. As a result, it is impracticable for the Company to provide accurate historical or current reporting among its various product lines.

Accounting_Policies

Accounting Policies	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Accounting Policies	'
	Accounting Policies
	Accounting Principles
	The financial statements and accompanying notes are prepared in accordance with accounting principles generally accepted in the United States.
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated.
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. Estimates also affect the amounts of revenue and expenses during the reported periods. Significant estimates included in these consolidated financial statements include:
	•	Allowances for doubtful accounts receivable
	•	Income tax accruals
	•	Uncertain tax positions
	•	Tax valuation reserves
	•	Fair value of stock-based compensation
	•	Contract revenue
	•	Useful lives for depreciation and amortization
	•	Valuations of goodwill and other intangible assets
	•	Contingent consideration
	•	Deferred compensation
	•	Loss contingencies
	Actual results could differ from these estimates. Changes in estimates are recorded in the results of operations in the period that the changes occur.
	Revenue Recognition
	Revenue is derived principally from the licensing of computer software products and from related maintenance contracts. Revenue from perpetual licenses is classified as license revenue and is recognized upon delivery of the licensed product and the utility that enables the customer to access authorization keys, provided that acceptance has occurred and a signed contractual obligation has been received, the price is fixed and determinable, and collectibility of the receivable is probable. The Company determines the fair value of PCS sold together with perpetual licenses based on the rate charged for PCS when sold separately. Revenue from PCS contracts is classified as maintenance and service revenue and is recognized ratably over the term of the contract.
	Revenue for software lease licenses is classified as license revenue and is recognized over the period of the lease contract. Typically, the Company’s software leases include PCS which, due to the short term (principally one year or less) of the Company’s software lease licenses, cannot be separated from lease revenue for accounting purposes. As a result, both the lease license and PCS are recognized ratably over the lease period. Due to the short-term nature of the software lease licenses and the frequency with which the Company provides major product upgrades (typically every 12–18 months), the Company does not believe that a significant portion of the fee paid under the arrangement is attributable to the PCS component of the arrangement and, as a result, includes the revenue for the entire arrangement within software license revenue in the consolidated statements of income.
	The Company's Apache products are typically licensed via longer term leases of 24–36 months.  The Company recognizes revenue for these licenses over the term of the lease contract.  Because the Company does not have vendor-specific objective evidence of the fair value of these leases, the Company also recognizes revenue from perpetual licenses over the term of the lease contract during the infrequent occurrence of these licenses being sold with Apache leases in multiple-element arrangements.
	Revenue from training, support and other services is recognized as the services are performed. The Company applies the specific performance method to contracts in which the service consists of a single act, such as providing a training class to a customer, and the proportional performance method to other service contracts that are longer in duration and often include multiple acts (for example, both training and consulting). In applying the proportional performance method, the Company typically utilizes output-based estimates for services with contractual billing arrangements that are not based on time and materials, and estimates output based on the total tasks completed as compared to the total tasks required for each work contract. Input-based estimates are utilized for services that involve general consultations with contractual billing arrangements based on time and materials, utilizing direct labor as the input measure.
	The Company also executes arrangements through independent channel partners in which the channel partners are authorized to market and distribute the Company’s software products to end-users of the Company’s products and services in specified territories. In sales facilitated by channel partners, the channel partner bears the risk of collection from the end-user customer. The Company recognizes revenue from transactions with channel partners when the channel partner submits a written purchase commitment, collectibility from the channel partner is probable, a signed license agreement is received from the end-user customer and delivery has occurred, provided that all other revenue recognition criteria are satisfied. Revenue from channel partner transactions is the amount remitted to the Company by the channel partners. This amount includes a fee for PCS that is compensation for providing technical enhancements and the second level of technical support to the end-user, which is based on the rate charged for PCS when sold separately, and is recognized over the period that PCS is to be provided. The Company does not offer right of return, product rotation or price protection to any of its channel partners.
	Non-income related taxes collected from customers and remitted to governmental authorities are recorded on the consolidated balance sheet as accounts receivable and accrued expenses. The collection and payment of these amounts are reported on a net basis in the consolidated statements of income and do not impact reported revenues or expenses.
	The Company warrants to its customers that its software will substantially perform as specified in the Company’s most current user manuals. The Company has not experienced significant claims related to software warranties beyond the scope of maintenance support, which the Company is already obligated to provide, and consequently the Company has not established reserves for warranty obligations.
	Cash and Cash Equivalents
	Cash and cash equivalents consist primarily of highly liquid investments such as deposits held at major banks and money market mutual funds with original maturities of three months or less. Cash equivalents are carried at cost, which approximates fair value. The Company’s cash and cash equivalents balances comprise the following:
		31-Dec-13					31-Dec-12
	(in thousands, except percentages)	Amount			% of Total		Amount				% of Total
	Cash accounts	$	439,348		59.2		$	369,724			64.1
	Money market mutual funds	303,138			40.8		206,979				35.9
	Total	$	742,486				$	576,703
	The Company held 99% and 98% of its money market mutual fund balances in various funds of a single issuer as of December 31, 2013 and December 31, 2012, respectively.
	Short-term Investments
	Short-term investments consist primarily of deposits held by certain foreign subsidiaries of the Company with original maturities of three months to one year. The Company considers investments backed by government agencies or financial institutions with maturities of less than one year to be highly liquid and classifies such investments as short-term investments. Short-term investments are recorded at fair value. The Company uses the specific identification method to determine the realized gain or loss upon the sale of such securities.
	The Company is averse to principal loss and seeks to preserve invested funds by limiting default risk, market risk and reinvestment risk by placing its investments with high-quality credit issuers.
	Property and Equipment
	Property and equipment is stated at cost. Depreciation is computed on the straight-line method over the estimated useful lives of the various classes of assets, which range from one to 40 years. Repairs and maintenance are charged to expense as incurred. Gains or losses from the sale or retirement of property and equipment are included in operating income.
	Research and Development
	Research and development costs, other than certain capitalized software development costs, are expensed as incurred.
	Software Development Costs
	Internally developed software costs required to be capitalized as defined by the accounting guidance were not material to the Company's consolidated financial statements in 2013, 2012 and 2011.
	Business Combinations
	When the Company consummates an acquisition, the assets acquired and the liabilities assumed are recognized separately from goodwill, at their acquisition date fair values. Goodwill as of the acquisition date is measured as the excess of the fair value of consideration transferred over the net of the acquisition date fair values of the assets acquired and the liabilities assumed. While best estimates and assumptions are used to accurately value assets acquired and liabilities assumed at the acquisition date as well as contingent consideration, where applicable, the Company's estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company records adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill based on refinements to information regarding what was known and knowable as of the acquisition date. Upon the earlier of the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, any subsequent adjustments are recorded in the consolidated statements of income.
	Goodwill and Other Intangible Assets
	Goodwill represents the excess of the consideration transferred over the fair value of net identifiable assets acquired. Other intangible assets consist of trademarks, customer lists, contract backlog, and acquired software and technology. Intangible assets that are not considered to have an indefinite useful life are amortized over their useful lives, which are generally three to 15 years. Amortization expense for intangible assets was $60.7 million, $67.3 million and $51.7 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	The Company tests goodwill and indefinite-lived intangible assets for impairment at least annually by performing a qualitative assessment of whether there is sufficient evidence that it is more likely than not that the fair value of each reporting unit or asset exceeds its carrying amount. Goodwill is tested at the reporting unit level and indefinite-lived intangible assets are tested at the individual asset level. The application of a qualitative assessment requires the Company to assess and make judgments regarding a variety of factors which potentially impact the fair value of the reporting unit or asset being tested, including general economic conditions, industry and market-specific conditions, customer behavior, cost factors, the Company's financial performance and trends, the Company's strategies and business plans, capital requirements, management and personnel issues, and the Company's stock price, among others. The Company then considers the totality of these and other factors, placing more weight on the events and circumstances that are judged to most affect the reporting unit's or asset's fair value and carrying amount, to reach a qualitative conclusion regarding whether it is more likely than not that the fair value of a reporting unit or asset is less than its carrying amount.
	If it is determined that it is more likely than not that the fair value of a reporting unit or asset exceeds its carrying value, no further analysis is necessary. If it is determined that it is more likely than not the reporting unit's or asset's carrying value exceeds its fair value, a quantitative two-step analysis is performed where the fair value of the reporting unit or asset is estimated and the impairment loss, if any, is recorded.
	The Company performs its annual impairment tests for goodwill and indefinite-lived intangible assets on January 1 of each year unless there is an indicator that would require a test during the year. The Company periodically reviews the carrying value of other intangible assets and will recognize impairments when events or circumstances indicate that such assets may be impaired.
	Concentrations of Credit Risk
	The Company has a concentration of credit risk with respect to revenue and trade receivables due to the use of certain significant channel partners to market and sell the Company’s products. The Company performs periodic credit evaluations of its customers’ financial condition and generally does not require collateral. The following table outlines concentrations of risk with respect to the Company’s revenue:
			Year Ended December 31,
	(as a % of revenue, except customer data)		2013		2012			2011
	Revenue from channel partners		25	%	26	%		26	%
	Largest channel partner		6	%	6	%		4	%
	2nd largest channel partner		2	%	3	%		3	%
	No single direct sale customer accounted for more than 5% of the Company's revenue in 2013, 2012 or 2011.
	In addition to the concentration of credit risk with respect to trade receivables, the Company’s cash and cash equivalents are also exposed to concentration of credit risk. The Company's cash and cash equivalent accounts are insured through various public and private bank deposit insurance programs, foreign and domestic; however, a significant portion of the Company's funds are not insured. The following table outlines concentrations of risk with respect to the Company's cash and cash equivalents:
		As of December 31,
	(in thousands)	2013			2012
	Cash and cash equivalents held domestically	$	530,680		$	399,295
Cash and cash equivalents held by foreign subsidiaries	211,806			177,408
Cash and cash equivalents held in excess of deposit insurance, foreign and domestic	717,589			559,023
Cash and cash equivalents held with one U.S. financial institution, foreign and domestic	378,562			296,270
Allowance for Doubtful Accounts
The Company makes judgments as to its ability to collect outstanding receivables and provides allowances for a portion of receivables when collection becomes doubtful. Provisions are made based upon a specific review of all significant outstanding invoices from both value and delinquency perspectives. For those invoices not specifically reviewed, provisions are provided at differing rates based upon the age of the receivable and the geographic area of origin. In determining these percentages, the Company considers its historical collection experience and current economic trends in the customer’s industry and geographic region. The Company recorded provisions for doubtful accounts of $1.5 million, $0.9 million and $0.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.
Income Taxes
The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period of the enactment date.
The Company records net deferred tax assets to the extent it believes these assets will more likely than not be realized. In making such determination, the Company considers all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial operations. In the event the Company determines that it will be able to realize deferred income tax assets in the future in excess of their net recorded amount, an adjustment to the valuation allowance would be recorded that would reduce the provision for income taxes.
Tax benefits related to uncertain tax positions taken or expected to be taken on a tax return are recorded when such benefits meet a more likely than not threshold. Otherwise, these tax benefits are recorded when a tax position has been effectively settled, which means that the statute of limitations has expired or the appropriate taxing authority has completed their examination even though the statute of limitations remains open. The Company recognizes interest and penalties related to unrecognized tax benefits within the income tax expense line in the accompanying consolidated statements of income. Accrued interest and penalties are included within the related tax liability line in the consolidated balance sheets.
Foreign Currencies
Certain of the Company’s sales and intercompany transactions are denominated in foreign currencies. These transactions are translated to the functional currency at the exchange rate on the transaction date. Assets and liabilities denominated in a currency other than the Company's or subsidiary's functional currency are translated at the effective exchange rate on the balance sheet date. Gains and losses resulting from foreign exchange transactions are included in other expense. The Company recorded net foreign exchange losses of $1.1 million, $1.4 million and $0.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.
The financial statements of the Company’s foreign subsidiaries are translated from the functional (local) currency to U.S. Dollars. Assets and liabilities are translated at the exchange rates on the balance sheet date. Results of operations are translated at average exchange rates, which approximate rates in effect when the underlying transactions occur.
Accumulated Other Comprehensive Income
Accumulated other comprehensive income is composed entirely of foreign currency translation adjustments.
Earnings Per Share
Basic earnings per share ("EPS") amounts are computed by dividing earnings by the weighted average number of common shares outstanding during the period. Diluted EPS amounts assume the issuance of common stock for all potentially dilutive equivalents outstanding. To the extent stock options are anti-dilutive, they are excluded from the calculation of diluted EPS. The details of basic and diluted EPS are as follows:
		Year Ended December 31,
(in thousands, except per share data)		2013			2012				2011
Net income		$	245,327		$	203,483			$	180,675
Weighted average shares outstanding – basic		92,691			92,622				92,120
Dilutive effect of stock plans		2,448			2,332				2,261
Weighted average shares outstanding – diluted		95,139			94,954				94,381
Basic earnings per share		$	2.65		$	2.2			$	1.96
Diluted earnings per share		$	2.58		$	2.14			$	1.91
Anti-dilutive options		885			1,506				1,421
Stock-based Compensation
The Company accounts for stock-based compensation in accordance with share-based payment accounting guidance. The guidance requires an entity to measure the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award. The cost is recognized over the period during which an employee is required to provide service in exchange for the award, typically the vesting period.
Fair Value of Financial Instruments
The Company accounts for certain assets and liabilities at fair value in accordance with the accounting guidance applicable to fair value measurements and disclosures. The carrying values of cash, cash equivalents, accounts receivable, accounts payable, accrued expenses, other accrued liabilities and short-term obligations are deemed to be reasonable estimates of their fair values because of their short-term nature. The fair values of investments are based on quoted market prices for those or similar investments.
New Accounting Guidance
Testing Indefinite-Lived Intangible Assets for Impairment: In July 2012, new accounting guidance was issued regarding the requirement to test indefinite-lived intangible assets for impairment. Previous guidance required an entity to test indefinite-lived intangible assets for impairment, on at least an annual basis, by comparing the fair value of the asset with its carrying amount. If the carrying amount of the intangible asset exceeds its fair value, an entity should recognize an impairment loss in the amount of that excess. Under the new guidance, an entity has an option not to calculate annually the fair value of an indefinite-lived intangible asset if the entity determines that it is not more likely than not that the asset is impaired. If, after assessing the totality of events or circumstances, an entity determines it is not more likely than not that the asset is impaired, then performing the quantitative test is unnecessary. However, if an entity concludes otherwise, then it is required to perform the quantitative test and record any impairment if necessary. This guidance was adopted by the Company effective January 1, 2013, and it did not have any impact on the Company's financial position, results of operations or cash flows.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions
	Reaction Design
	On January 3, 2014, the Company completed the acquisition of Reaction Design, a leading developer of chemistry simulation software, for a purchase price of approximately $19 million. Reaction Design's solutions enable transportation manufacturers and energy companies to rapidly achieve their clean technology goals by automating the analysis of chemical processes via computer simulation and modeling solutions. The operating results of Reaction Design will be included in the Company's consolidated financial statements from the date of acquisition and, accordingly, Reaction Design's operating results are not included in the financial results presented in this annual report on Form 10-K.
	EVEN - Evolutionary Engineering AG
	On April 2, 2013, the Company acquired EVEN, a leading provider of composite analysis and optimization technology. Under the terms of the agreement, ANSYS acquired 100% of EVEN for a purchase price of $8.1 million, which consisted of $4.5 million in cash and an estimated $3.6 million of contingent consideration based on EVEN's achievement of certain technical milestones during the three years following the acquisition date.
	The operating results of EVEN have been included in the Company's consolidated financial statements since the date of acquisition. The total consideration transferred was allocated to the assets and liabilities of EVEN based on management's estimates of the fair values of the assets acquired and the liabilities assumed. The allocation included $2.6 million to identifiable intangible assets, including customer lists and core technology, to be amortized over a period of five years, and $5.9 million to goodwill, which is not tax deductible. The fair values of the assets acquired and liabilities assumed are based on preliminary calculations and the estimates and assumptions for these items are subject to change as additional information about what was known and knowable at the acquisition date is obtained during the measurement period (up to one year from the acquisition date). The operating results of EVEN are not material to the consolidated financial statements.
	Esterel Technologies, S.A.
	On August 1, 2012, the Company completed its acquisition of Esterel. Under the terms of the acquisition agreement, ANSYS acquired 100% of Esterel for a purchase price of $58.2 million, which included $13.1 million in acquired cash. The acquisition agreement also includes retention provisions for key members of Esterel's management and employees, which are accounted for outside of the business combination. The Company funded the transaction entirely with existing cash balances. The operating results of Esterel have been included in the Company's consolidated financial statements since the date of acquisition.
	In valuing deferred revenue on the Esterel balance sheet as of the acquisition date, the Company applied the fair value provisions applicable to the accounting for business combinations. Although this acquisition accounting requirement had no impact on the Company’s business or cash flow, the Company’s reported revenue under accounting principles generally accepted in the United States, primarily for the first 12 months post-acquisition, is less than the sum of what would otherwise have been reported by Esterel and ANSYS absent the acquisition. Acquired deferred revenue of $1.1 million was recorded on the opening balance sheet, which was $11.0 million lower than the historical carrying value. The impact on reported revenue for the year ended December 31, 2013 was $4.1 million. The expected impact on reported revenue is $0.4 million and $1.4 million for the quarter ending March 31, 2014 and for the year ending December 31, 2014, respectively.
	The assets and liabilities of Esterel have been recorded based upon management's estimates of their fair market values as of the acquisition date. The following tables summarize the fair value of consideration transferred and the fair values of identified assets acquired and liabilities assumed at the acquisition date:
	Fair Value of Consideration Transferred:
	(in thousands)
	Cash	$	58,150
	Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed:
	(dollars in thousands)
	Cash	$	13,075
	Accounts receivable and other tangible assets	4,737
	Customer relationships (12-year life)	21,421
	Developed software (10-year life)	10,717
	Platform trade name (indefinite life)	2,695
	Accounts payable and other liabilities	(4,707		)
	Deferred revenue	(1,139		)
	Net deferred tax liabilities	(7,096		)
	Total identifiable net assets	$	39,703
	Goodwill	$	18,447
	The goodwill, which is not tax deductible, is attributed to intangible assets that do not qualify for separate recognition, including the assembled workforce of the acquired business and the synergies expected to arise as a result of the acquisition of Esterel. During the one-year measurement period since the Esterel acquisition date, the Company decreased the value of net deferred tax liabilities from $10.0 million to $7.1 million, with the offset recorded to goodwill. This adjustment was based on additional information regarding what was known and knowable in the calculation of the net deferred tax liabilities as of the acquisition date.
	Pro forma results of operations have not been presented as the effects of the Esterel business combination were not material to the Company's consolidated results of operations.
	Apache Design, Inc.
	On August 1, 2011, the Company completed its acquisition of Apache, a leading simulation software provider for advanced, low-power solutions in the electronics industry. Under the terms of the merger agreement, ANSYS acquired 100% of the outstanding shares of Apache for a purchase price of $314.0 million, which included $31.9 million in acquired cash and short-term investments on Apache’s balance sheet, $3.2 million in ANSYS replacement stock options issued to holders of partially-vested Apache stock options and $9.5 million in contingent consideration that is based on the retention of a key member of Apache’s management. The Company funded the transaction entirely with existing cash balances. The operating results of Apache have been included in the Company’s consolidated financial statements since the date of acquisition.
	The assets and liabilities of Apache have been recorded based on management’s estimates of their fair market values as of the acquisition date. The following tables summarize the fair value of consideration transferred and the fair values of identifiable assets acquired and liabilities assumed at the acquisition date:
	Fair Value of Consideration Transferred:
	(in thousands)
	Cash	$	301,306
	Contingent consideration	9,501
	ANSYS replacement stock options	3,170
	Total consideration transferred at fair value	$	313,977
	Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed:
	(dollars in thousands)
	Cash and short-term investments	$	31,948
	Accounts receivable and other tangible assets	6,011
	Developed software (7-year life)	82,500
	Customer relationships (15-year life)	36,100
	Contract backlog (3-year life)	13,500
	Platform trade names (indefinite lives)	21,900
	Apache trade name (6-year life)	2,100
	Accounts payable and other liabilities	(16,867		)
	Deferred revenue	(10,100		)
	Net deferred tax liabilities	(47,229		)
	Total identifiable net assets	$	119,863
	Goodwill	$	194,114
	The goodwill, which is not tax-deductible, is attributed to intangible assets that do not qualify for separate recognition, including the assembled workforce of the acquired business and the synergies expected to arise as a result of the acquisition of Apache.

Other_Current_Assets

Other Current Assets	12 Months Ended
	Dec. 31, 2013
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'
Other Current Assets	'
	Other Current Assets
	The Company reports accounts receivable, related to the current portion of annual lease licenses and software maintenance that has not yet been recognized as revenue, as components of other receivables and current assets. The amounts reported in other receivables and current assets totaled $140.1 million and $149.3 million as of December 31, 2013 and 2012, respectively.
	The Company reports income taxes receivable, including amounts related to overpayments and refunds, as a component of other receivables and current assets. These amounts totaled $42.4 million and $48.9 million as of December 31, 2013 and 2012, respectively.

Other_LongTerm_Liabilities

Other Long-Term Liabilities	12 Months Ended
	Dec. 31, 2013
Other Liabilities Disclosure [Abstract]	'
Other Long-Term Liabilities	'
	Other Long-Term Liabilities
	The Company reports reserves for uncertain tax positions, including estimated penalties and interest, in the consolidated balance sheets. These amounts totaled $18.8 million and $37.0 million as of December 31, 2013 and December 31, 2012, respectively.

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Property and Equipment	'
	Property and Equipment
	Property and equipment consists of the following:
			December 31,
	(dollars in thousands)	Estimated Useful Lives	2013			2012
	Equipment	1-10 years	$	68,970		$	59,580
	Computer software	1-5 years	27,647			26,864
	Buildings	10-40 years	24,325			15,122
	Leasehold improvements	1-10 years	8,125			7,334
	Furniture	1-10 years	4,973			4,457
	Land		2,178			2,178
			136,218			115,535
	Less: Accumulated depreciation and amortization		(75,680		)	(63,282		)
			$	60,538		$	52,253
	Depreciation and amortization expense related to property and equipment, including the amounts acquired through capital lease commitments, was $19.9 million, $17.4 million and $13.3 million for the years ended December 31, 2013, 2012 and 2011, respectively.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets	'
	Goodwill and Intangible Assets
	Goodwill represents the excess of the fair value of the consideration transferred over the value of net tangible and identifiable intangible assets of acquired businesses. Identifiable intangible assets acquired in business combinations are recorded based on their fair values on the date of acquisition.
	During the first quarter of 2013, the Company completed the annual impairment test for goodwill and indefinite-lived intangible assets and determined that these assets had not been impaired as of the test date, January 1, 2013. The Company performed qualitative assessments to test goodwill and indefinite-lived intangible assets for impairment, and as of the test date, there was sufficient evidence that it was not more likely than not that the fair values of its reporting units and indefinite-lived intangible assets were less than their carrying amounts. No events occurred or circumstances changed during the year ended December 31, 2013 that would indicate that the fair values of the Company’s reporting units and indefinite-lived intangible assets are below their carrying amounts.
	The Company’s intangible assets and estimated useful lives are classified as follows:
		31-Dec-13						31-Dec-12
	(dollars in thousands)	Gross			Accumulated			Gross		Accumulated
		Carrying			Amortization			Carrying		Amortization
		Amount						Amount
	Finite-lived intangible assets:
	Developed software and core technologies (5 – 10 years)	$	300,493		$	(203,236	)	$	298,802	$	(175,988	)
	Customer lists and contract backlog (3 – 15 years)	237,173			(119,368		)	241,721		(100,702		)
	Trade names (6 – 10 years)	102,651			(50,990		)	102,629		(40,436		)
	Total	$	640,317		$	(373,594	)	$	643,152	$	(317,126	)
	Indefinite-lived intangible assets:
	Trade names	$	24,667					$	25,147
	Amortization expense for the intangible assets reflected above was $60.7 million, $67.3 million and $51.7 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	As of December 31, 2013, estimated future amortization expense for the intangible assets reflected above is as follows:
	(in thousands)
	2014	$	54,119
	2015	50,482
	2016	43,374
	2017	39,604
	2018	25,982
	Thereafter	53,162
	Total intangible assets subject to amortization	266,723
	Indefinite-lived trade names	24,667
	Other intangible assets, net	$	291,390
	The changes in goodwill during the years ended December 31, 2013 and 2012 are as follows:
	(in thousands)	2013			2012
	Beginning balance - January 1	$	1,251,247		$	1,225,375
	Acquisitions of EVEN and Esterel, respectively	5,936			20,866
	Currency translation and other	(1,479		)	5,006
	Ending balance - December 31	$	1,255,704		$	1,251,247

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	Long-Term Debt
	The Company paid the outstanding balance on its term loan at maturity on July 31, 2013. For the years ended December 31, 2013, 2012 and 2011, the Company recorded interest expense related to the term loan at average interest rates of 1.04%, 1.22% and 1.05%, respectively. The interest expense on the term loan and amortization related to debt financing costs are as follows:
		Year Ended December 31,
		2013				2012				2011
	(in thousands)	Interest		Amortization		Interest		Amortization		Interest		Amortization
		Expense				Expense				Expense
	July 31, 2008 term loan	$	230	$	149	$	1,342	$	698	$	1,605	$	953

Fair_Value_Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurement	'
	Fair Value Measurement
	The valuation hierarchy for disclosure of assets and liabilities reported at fair value prioritizes the inputs for such valuations into three broad levels:
	•	Level 1: quoted prices (unadjusted) in active markets for identical assets or liabilities;
	•	Level 2: quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument; or
	•	Level 3: unobservable inputs based on the Company’s own assumptions used to measure assets and liabilities at fair value.
	A financial asset's or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement.
	The following tables provide the assets and liabilities carried at fair value and measured on a recurring basis:
					Fair Value Measurements at Reporting Date Using:
	(in thousands)	31-Dec-13			Quoted Prices in			Significant Other			Significant
					Active Markets			Observable			Unobservable
					(Level 1)			Inputs			Inputs
								(Level 2)			(Level 3)
	Assets
	Cash equivalents	$	303,138		$	303,138		$	—		$	—
	Short-term investments	$	500		$	—		$	500		$	—
	Liabilities
	Contingent consideration	$	(7,389	)	$	—		$	—		$	(7,389	)
	Deferred compensation	$	(704	)	$	—		$	—		$	(704	)
					Fair Value Measurements at Reporting Date Using:
	(in thousands)	31-Dec-12			Quoted Prices in			Significant Other			Significant
					Active Markets			Observable			Unobservable
					(Level 1)			Inputs			Inputs
								(Level 2)			(Level 3)
	Assets
	Cash equivalents	$	206,979		$	206,979		$	—		$	—
	Short-term investments	$	452		$	—		$	452		$	—
	Liabilities
	Contingent consideration	$	(6,436	)	$	—		$	—		$	(6,436	)
	Deferred compensation	$	(1,394	)	$	—		$	—		$	(1,394	)
	Foreign currency future	$	(240	)	$	—		$	(240	)	$	—
	The cash equivalents in the preceding tables represent money market mutual funds and time deposits.
	The short-term investments in the preceding tables represent deposits held by certain foreign subsidiaries of the Company. The deposits have fixed interest rates with maturity dates ranging from three months to one year.
	The contingent consideration in the table above represents potential future payments related to the EVEN and Apache acquisitions in accordance with the respective merger agreements. The deferred compensation in the table above is attributable to a retention agreement for a key member of Apache management, and was accounted for outside of that business combination. The net present value calculations for the contingent consideration and deferred compensation include significant unobservable inputs in the assumption that all remaining payments will be made, and therefore the liabilities were classified as Level 3 in the fair value hierarchy.
	The foreign currency future contract was settled in August 2013 and did not have a material impact on the Company's results of operations for the year ended December 31, 2013.
	The following table presents the changes during the years ended December 31, 2013 and 2012 in the Company’s Level 3 liabilities for contingent consideration and deferred compensation that are measured at fair value on a recurring basis:
		Fair Value Measurement Using
		Significant Unobservable Inputs
	(in thousands)	Contingent			Deferred
		Consideration			Compensation
	Balance as of January 1, 2012	$	9,571		$	2,073
	Contingent payments	(3,288		)	(712		)
	Interest expense included in earnings	153			33
	Balance as of December 31, 2012	$	6,436		$	1,394
	EVEN contingent consideration	3,597			—
	Contingent payments	(3,288		)	(712		)
	Interest expense and foreign exchange activity included in earnings	644			22
	Balance as of December 31, 2013	$	7,389		$	704
	The carrying values of cash, accounts receivable, accounts payable, accrued expenses, other accrued liabilities and short-term obligations approximate their fair values because of their short-term nature.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	Income before income taxes includes the following components:
		Year Ended December 31,
	(in thousands)	2013				2012				2011
	Domestic	$	272,569			$	234,497			$	205,966
	Foreign	49,920				59,050				58,892
	Total	$	322,489			$	293,547			$	264,858
	The provision for income taxes is composed of the following:
		Year Ended December 31,
	(in thousands)	2013				2012				2011
	Current:
	Federal	$	69,268			$	79,028			$	57,423
	State	7,197				7,886				5,770
	Foreign	24,722				22,046				24,011
	Deferred:
	Federal	(23,438		)		(21,026		)		(11,768		)
	State	(2,187		)		(3,913		)		(1,314		)
	Foreign	1,600				6,043				10,061
	Total	$	77,162			$	90,064			$	84,183
	The reconciliation of the U.S. federal statutory tax rate to the consolidated effective tax rate is as follows:
		Year Ended December 31,
		2013			2012			2011
	Federal statutory tax rate	35	%		35	%		35	%
	State income taxes, net of federal benefit	1.1			1.2			1.1
	Stock-based compensation	0.9			1			1
	Changes in tax rates	0.3			0.8			2.2
	Net (benefit) tax of unrepatriated earnings	(0.9	)		0.7			—
	Uncertain tax positions	(3.7	)		0.3			0.2
	Research and experimentation credits	(2.0	)		(0.1	)		(0.9	)
	Adjustments of prior year taxes	(0.1	)		(1.3	)		(0.3	)
	Foreign rate differential	(0.9	)		(1.9	)		(1.1	)
	Benefit from restructuring activities	(2.8	)		(3.1	)		(3.5	)
	Domestic production activity benefit	(3.3	)		(3.3	)		(2.9	)
	Other	0.3			1.4			1
		23.9	%		30.7	%		31.8	%
	In general, it is the practice and intention of the Company to repatriate previously taxed earnings and to reinvest all other earnings of its non-U.S. subsidiaries. The Company has not made a provision for U.S. taxes on $173.1 million, representing the excess of the amount for financial reporting over the tax bases of investments in foreign subsidiaries that are essentially permanent in duration. Generally, such amounts become subject to U.S. taxation upon the remittance of dividends and under certain other circumstances. The residual U.S. tax cost associated with this difference is estimated to be $46.1 million. The Company has recorded a tax benefit of $0.1 million related to $15.8 million of earnings that it expects to repatriate from a foreign subsidiary.
	The components of deferred tax assets and liabilities are as follows:
		December 31,
	(in thousands)	2013				2012
	Deferred tax assets:
	Net operating loss carryforwards	$	26,204			$	26,228
	Employee benefits	18,824				17,670
	Stock-based compensation	20,006				16,092
	Foreign tax credits	403				558
	Other accruals not currently deductible	1,165				1,207
	Research and development credits	2,331				2,254
	Uncertain tax positions	7,977				7,790
	Deferred revenue	7,816				5,139
	Allowance for doubtful accounts	2,014				1,661
	Other	1,953				2,227
	Valuation allowance	(392		)		(14		)
		88,301				80,812
	Deferred tax liabilities:
	Other intangible assets	(106,115		)		(128,671		)
	Property and equipment	(4,556		)		(5,838		)
	Unremitted foreign earnings	(115		)		(2,204		)
		(110,786		)		(136,713		)
	Net deferred tax liabilities	$	(22,485	)		$	(55,901	)
	As of December 31, 2013, the Company had federal net operating loss carryforwards of $4.6 million. These losses expire between 2024 - 2029, and are subject to limitations on their utilization. The Company had total foreign net operating loss carryforwards of $70.6 million, of which $19.5 million are not currently subject to expiration dates. The remainder, $51.1 million, expires between 2019 and 2021. The Company had tax credit carryforwards of $4.1 million, of which $1.2 million are subject to limitations on their utilization. Approximately $1.8 million of these tax credit carryforwards are not currently subject to expiration dates. The remainder, $2.3 million, expires in various years between 2030 and 2033.
	In December 2013, the Company received notice from the Internal Revenue Service that the Joint Committee on Taxation took no exception to the Company's tax returns that were filed for 2009 and 2010. An $11.0 million tax benefit was recognized in the Company's 2013 financial results as the Company has effectively settled uncertainty regarding refund claims filed in connection with these returns.
	The following is a reconciliation of the total amounts of unrecognized tax benefits:
		Year Ended December 31,
	(in thousands)	2013				2012				2011
Unrecognized tax benefit as of January 1	$	37,203			$	31,582			$	19,993
Acquired unrecognized tax benefit	—				3,845				5,813
Gross increases—tax positions in prior period	320				2,048				6,814
Gross decreases—tax positions in prior period	(18,058		)		(2,167		)		(2,697		)
Gross increases—tax positions in current period	2,036				2,660				2,297
Reductions due to a lapse of the applicable statute of limitations	(1,734		)		(1,314		)		(190		)
Changes due to currency fluctuation	20				625				(448		)
Settlements	(197		)		(76		)		—
Unrecognized tax benefit as of December 31	$	19,590			$	37,203			$	31,582
The Company believes that it is reasonably possible that $0.7 million of uncertain tax positions will be resolved within the next twelve months. Of the total unrecognized tax benefit as of December 31, 2013, $15.8 million would affect the effective tax rate, if recognized.
The Company recognizes interest and penalties related to unrecognized tax benefits as income tax expense. As of December 31, 2013, the Company accrued a liability for penalties of $1.6 million and interest of $2.7 million. As of December 31, 2012, the Company accrued a liability for penalties of $2.1 million and interest of $2.5 million.
The Company is subject to taxation in the U.S. and various states and foreign jurisdictions. The Company’s 2008 through 2013 tax years are open to examination by the Internal Revenue Service. The 2008 and 2011 federal returns are currently under examination. The Company also has various foreign and state tax filings subject to examination for various years.

Pension_And_ProfitSharing_Plan

Pension And Profit-Sharing Plans	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Pension And Profit-Sharing Plans	'
	Pension and Profit-Sharing Plans
	The Company has a 401(k)/profit-sharing plan for all qualifying full-time domestic employees that permits participants to make contributions by salary reduction pursuant to Section 401(k) of the Internal Revenue Code. The Company makes matching contributions on behalf of each eligible participant in an amount equal to 100% of the first 3% and an additional 25% of the next 5%, for a maximum total of 4.25% of the employee’s compensation. The Company may make a discretionary contribution based on the participant’s eligible compensation, provided the employee is employed at the end of the year and has worked at least 1,000 hours. The Company also maintains various defined contribution and defined benefit pension arrangements for its international employees. The Company funds the foreign defined benefit and contribution plans based on the minimum required deposits according to the local statutory requirements. The unfunded portion of the defined benefit obligation for each plan is accrued in other long-term liabilities.
	Expenses related to the Company’s retirement programs were $8.0 million in 2013, $7.1 million in 2012 and $5.3 million in 2011.

NonCompete_and_Employment_Agre

Non-Compete and Employment Agreements	12 Months Ended
	Dec. 31, 2013
Non-Compete and Employment Agreements [Abstract]	'
Non-Compete and Employment Agreements	'
	Non-Compete and Employment Agreements
	Employees of the Company have signed agreements under which they have agreed not to disclose trade secrets or confidential information and, where legally permitted, that restrict engagement in or connection with any business that is competitive with the Company anywhere in the world while employed by the Company (and, in some cases, for specified periods thereafter), and that any products or technology created by them during their term of employment are the property of the Company. In addition, the Company requires all channel partners to enter into agreements not to disclose the Company’s trade secrets and other proprietary information.
	The Company has an employment agreement with the Chairman of its Board of Directors. In the event the Chairman is terminated without cause, his employment agreement provides for severance at an annual rate of $300,000 for the earlier of a period of one year after termination or when he accepts other employment. The Chairman is subject to a one-year restriction on competition following termination of employment under the circumstances described in the contract.
	The Company has an employment agreement with the Chief Executive Officer. This agreement provides for, among other things, minimum severance payments equal to his base salary, target bonus and then-existing benefits through the earlier of the second anniversary of the termination date if the Chief Executive Officer is terminated without cause or when he accepts other employment. The Chief Executive Officer is subject to a two-year restriction on competition following termination of employment under the circumstances described in the contract.
	The Company also has employment agreements with several other employees, primarily in foreign jurisdictions. The terms of these employment agreements generally include annual compensation, severance payment provisions and non-compete clauses.

Stock_Option_And_Grant_Plan

Stock Option And Grant Plan	12 Months Ended
	Dec. 31, 2013
Stock Option And Grant Plan [Abstract]	'
Stock Option And Grant Plan	'
	Stock-based Compensation
	The Company has a stock option and grant plan—the Fourth Amended and Restated 1996 Stock Option and Grant Plan ("Stock Plan"). The Stock Plan, as amended, authorizes the grant of up to 30,400,000 shares of the Company’s common stock in the form of: (i) incentive stock options ("ISOs"), (ii) nonqualified stock options or (iii) the issuance or sale of common stock with or without vesting or other restrictions. Additionally, the Stock Plan permits (a) the grant of common stock upon the attainment of specified performance goals, (b) the grant of restricted stock awards, (c) the grant of the right to receive cash dividends with the holders of the common stock as if the recipient held a specified number of shares of the common stock, (d) the grant of deferred stock awards, (e) the grant of stock appreciation rights and (f) the grant of cash-based awards.
	The Stock Plan provides that: (i) the exercise price of an ISO must be no less than the fair value of the stock at the date of grant and (ii) the exercise price of an ISO held by an optionee who possesses more than 10% of the total combined voting power of all classes of stock must be no less than 110% of the fair market value of the stock at the time of grant. The Compensation Committee of the Board of Directors has the authority to set expiration dates no later than ten years from the date of grant (or five years for an optionee who meets the 10% criteria), payment terms and other provisions for each grant. The majority of options granted have a four-year vesting period. Shares associated with unexercised options or reacquired shares of common stock (except those shares withheld as a result of tax withholding or net issuance) become available for options or issuances under the Stock Plan. The Compensation Committee of the Board of Directors may, at its sole discretion, accelerate or extend the date or dates on which all or any particular award or awards granted under the Stock Plan may vest or be exercised.
	In the event of a "sale event" as defined in the Stock Plan, all outstanding awards will be assumed or continued by the successor entity, with appropriate adjustment in the awards to reflect the transaction. In such event, except as the Compensation Committee may otherwise specify with respect to particular awards in the award agreements, if the service relationship of the holder of an award is terminated without cause within 18 months after the sale event, then all awards held by such holder will become fully vested and exercisable at that time. If there is a sale event in which the successor entity refuses to assume or continue outstanding awards, then subject to the consummation of the sale event, all awards with time-based vesting conditions will become fully vested and exercisable at the effective time of the sale event and all awards with performance-based vesting conditions may become vested and exercisable in accordance with the award agreements at the discretion of the Compensation Committee. If awards are not assumed or continued after a sale event, then all such awards will terminate at the time of the sale event. In the event of the termination of stock options or stock appreciation rights in connection with a sale event, the Compensation Committee may either make or provide for a cash payment to the holders of such awards equal to the difference between the per share transaction consideration and the exercise price of such awards or permit each holder to have at least a 15-day period to exercise such awards prior to their termination. In addition, options granted to Independent Directors and certain key executives prior to February 17, 2011 vest automatically upon a sale event.
	The Company grants deferred stock units to non-affiliate Independent Directors, which are rights to receive shares of common stock upon termination of service as a Director. The deferred stock units are issued in arrears and vest immediately. As of December 31, 2013, 115,842 deferred stock units have been earned with the underlying shares remaining unissued until the service termination of the respective Director owners. Of this amount, 26,215 units were earned during the year ended December 31, 2013.
	The Company currently issues shares related to exercised stock options from its existing pool of treasury shares and has no specific policy to repurchase treasury shares as stock options are exercised. If the treasury pool is depleted, the Company will issue new shares.
	Information regarding stock option transactions is summarized below:
			Year Ended December 31,
			2013							2012							2011
	(options in thousands)		Options			Weighted				Options			Weighted				Options		Weighted
						Average							Average						Average
						Exercise							Exercise						Exercise
						Price							Price						Price
	Outstanding, beginning of year		7,122			$	42.85			7,545			$	35.1			7,319		$	29.92
	Granted		103			$	81.87			1,109			$	67.53			1,104		$	58.5
	Issued pursuant to Apache acquisition		—			$	—			—			$	—			418		$	18.66
	Exercised		(993	)		$	34.26			(1,464	)		$	21.85			(1,179	)	$	19.33
	Forfeited		(66	)		$	53.75			(68	)		$	36.9			(117	)	$	33.27
	Outstanding, end of year		6,166			$	44.77			7,122			$	42.85			7,545		$	35.1
	Vested and Exercisable, end of year		4,351			$	38.18			4,094			$	33.91			4,251		$	27.98
			2013				2012				2011
	Weighted Average Remaining Contractual Term (in years)
	Outstanding		5.99				6.78				6.66
	Vested and Exercisable		5.13				5.48				5.2
	Aggregate Intrinsic Value (in thousands)
	Outstanding		$	261,601			$	174,383			$	168,837
	Vested and Exercisable		$	213,304			$	136,851			$	124,550
	Historical and future expected forfeitures have not been significant and, as a result, the outstanding option amounts reflected in the tables above approximate the options expected to vest.
	Total stock-based compensation expense recognized for the years ended December 31, 2013, 2012 and 2011 is as follows:
			Year Ended December 31,
	(in thousands, except per share amounts)		2013				2012				2011
	Cost of sales:
	Software licenses		$	1,349			$	1,478			$	556
	Maintenance and service		2,293				2,232				1,897
	Operating expenses:
	Selling, general and administrative		16,847				15,278				12,501
	Research and development		14,809				13,427				8,134
	Stock-based compensation expense before taxes		35,298				32,415				23,088
	Related income tax benefits		(11,096		)		(8,509		)		(5,552		)
	Stock-based compensation expense, net of taxes		$	24,202			$	23,906			$	17,536
	Net impact on earnings per share:
	Basic earnings per share		$	(0.26	)		$	(0.26	)		$	(0.19	)
	Diluted earnings per share		$	(0.25	)		$	(0.25	)		$	(0.19	)
	The fair value of each option grant is estimated on the date of grant or date of acquisition for options issued in a business combination using the Black-Scholes option pricing model, which was developed for use in estimating the fair value of traded options that have no vesting restrictions and are fully transferable. The Company’s options have characteristics significantly different from those of traded options, and changes in input assumptions can materially affect the fair value estimates. The interest rates used were determined by using the five-year Treasury Note yield at the date of grant or date of acquisition for options issued in a business combination. The volatility was determined based on the historic volatility of the Company’s stock during the preceding six years for 2013, 2012 and 2011.
	The table below presents the weighted average input assumptions used and resulting fair values for options granted or issued in business combinations during each respective year:
			Year Ended December 31,
			2013		2012		2011
	Risk-free interest rate		0.68% to 1.48%		0.59% to 1.04%		0.91% to 2.11%
	Expected dividend yield		—%		—%		—%
	Expected volatility		37%		38%		39%
	Expected term		5.8 years		6.0 years		5.8 years
	Weighted average fair value per share		$29.85		$24.82		$25.84
	As stock-based compensation expense recognized in the consolidated statements of income is based on awards ultimately expected to vest, it must be reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The effect of pre-vesting forfeitures on the Company’s recorded expense has historically been negligible due to the relatively low turnover of stock option holders.
	The Company’s determination of fair value of share-based payment awards on the date of grant using an option pricing model is affected by the Company’s stock price as well as assumptions regarding a number of variables. The total estimated grant date fair values of stock options that vested during the years ended December 31, 2013, 2012 and 2011 were $24.7 million, $23.3 million and $20.2 million, respectively. As of December 31, 2013, total unrecognized estimated compensation cost related to unvested stock options granted prior to that date was $39.9 million, which is expected to be recognized over a weighted average period of 1.7 years. The total intrinsic values of stock options exercised during the years ended December 31, 2013, 2012 and 2011 were $45.2 million, $64.7 million and $42.6 million, respectively. As of December 31, 2013, 1.8 million unvested options with an aggregate intrinsic value of $48.3 million are expected to vest and have a weighted average exercise price of $60.59 and a weighted average remaining contractual term of 8.0 years. The Company recorded cash received from the exercise of stock options of $34.0 million and related tax benefits of $21.1 million for the year ended December 31, 2013.
	Information regarding stock options outstanding as of December 31, 2013 is summarized below:
	(options in thousands)		Options Outstanding									Options Exercisable
	Range of Exercise Prices		Options			Weighted		Weighted				Options			Weighted
						Average		Average							Average
						Remaining		Exercise							Exercise
						Contractual		Price							Price
						Life (years)
	$5.91 - $28.40		1,747			3.64		$	22.4			1,662			$	22.44
	$29.97 - $40.89		1,272			4.79		$	39.54			1,269			$	39.53
$41.33 - $58.67		1,983			7.2		$	53.73			1,170			$	52.77
$60.49 - $88.35		1,164			8.64		$	68.8			250			$	67.55
Under the terms of the ANSYS, Inc. Long-Term Incentive Plan, in the first quarters of 2013, 2012 and 2011, the Company granted 94,300, 100,000 and 92,500 performance-based restricted stock units, respectively. Vesting of the full award or a portion thereof is based on the Company’s performance as measured by total shareholder return relative to the median percentage appreciation of the NASDAQ Composite Index over a specified measurement period, subject to each participant’s continued employment with the Company through the conclusion of the measurement period. The measurement period for the restricted stock units granted pursuant to the Long-Term Incentive Plan is a three-year period beginning January 1 of the year of the grant. Each restricted stock unit relates to one share of the Company’s common stock. The weighted average fair value of each restricted stock unit granted in 2013, 2012 and 2011 was estimated on the grant date to be $50.05, $33.16 and $32.05, respectively. The fair value of the restricted stock units was estimated using a Monte Carlo simulation model. The determination of the fair value of the awards was affected by the grant date and a number of variables, each of which has been identified in the chart below. Share-based compensation expense based on the fair value of the award is being recorded from the grant date through the conclusion of the three-year measurement period. On December 31, 2013, employees earned 92,500 restricted stock units, which will be issued in the first quarter of 2014. Total compensation expense associated with the awards recorded for the years ended December 31, 2013, 2012 and 2011 was $3.6 million, $2.6 million and $1.6 million, respectively. Total compensation expense associated with granted awards for the years ending December 31, 2014 and 2015 is expected to be $2.8 million and $1.7 million, respectively.
	Year Ended December 31,
Assumption used in Monte Carlo lattice pricing model	2013		2012		2011
Risk-free interest rate	0.35%		0.16%		1.35%
Expected dividend yield	—%		—%		—%
Expected volatility—ANSYS Stock Price	25%		28%		40%
Expected volatility—NASDAQ Composite Index	20%		20%		25%
Expected term	2.8 years		2.8 years		2.9 years
Correlation factor	0.7		0.75		0.7
In accordance with the Apache merger agreement, the Company granted performance-based restricted stock units to key members of Apache management and employees, with a maximum value of $13.0 million to be earned over a three-fiscal-year period beginning January 1, 2012. Vesting of the full award or a portion thereof is determined discretely for each of the three fiscal years based on the achievement of certain revenue and operating income targets by the Apache subsidiary, and the recipient’s continued employment through the measurement period. The value of each restricted stock unit on the August 1, 2011 grant date was $50.30, the closing price of ANSYS stock as of that date. Stock-based compensation expense based on the fair value of the awards is being recorded from the January 1, 2012 service inception date through the conclusion of the three-year measurement period based on management’s estimates concerning the probability of vesting. Total compensation expense associated with the awards recorded for the years ended December 31, 2013 and 2012, was $3.8 million and $3.9 million, respectively. For the year ended December 31, 2013, employees earned 75,477 restricted stock units, which will be issued in the first quarter of 2014.

Stock_Repurchase_Program

Stock Repurchase Program	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Stock Repurchase Program	'
	Stock Repurchase Program
	In February 2013, the Company announced that its Board of Directors approved an increase to its authorized stock repurchase program. Under the Company’s stock repurchase program, the Company repurchased 1.5 million shares during the year ended December 31, 2013 at an average price per share of $77.73, for a total cost of $116.1 million. During the year ended December 31, 2012, the Company repurchased 1.5 million shares at an average price per share of $63.65, for a total cost of $95.5 million. As of December 31, 2013, 1.5 million shares remained authorized for repurchase under the program.

Employee_Stock_Purchase_Plan

Employee Stock Purchase Plan	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Employee Stock Purchase Plan	'
	Employee Stock Purchase Plan
	The Company’s 1996 Employee Stock Purchase Plan (the “Purchase Plan”) was adopted by the Board of Directors on April 19, 1996 and was subsequently approved by the Company’s stockholders. The stockholders approved an amendment to the Purchase Plan on May 6, 2004 to increase the number of shares available for offerings to 1.6 million shares. The Purchase Plan was amended and restated in 2007. The Purchase Plan is administered by the Compensation Committee. Offerings under the Purchase Plan commence on each February 1 and August 1, and have a duration of six months. An employee who owns or is deemed to own shares of stock representing in excess of 5% of the combined voting power of all classes of stock of the Company may not participate in the Purchase Plan.
	During each offering, an eligible employee may purchase shares under the Purchase Plan by authorizing payroll deductions of up to 10% of his or her cash compensation during the offering period. The maximum number of shares that may be purchased by any participating employee during any offering period is limited to 3,840 shares (as adjusted by the Compensation Committee from time to time). Unless the employee has previously withdrawn from the offering, his accumulated payroll deductions will be used to purchase common stock on the last business day of the period at a price equal to 90% of the fair market value of the common stock on the first or last day of the offering period, whichever is lower. Under applicable tax rules, an employee may purchase no more than $25,000 worth of common stock in any calendar year. As of December 31, 2013, 1,282,578 shares of common stock had been issued under the Purchase Plan, of which 1,233,385 were issued as of December 31, 2012. The total compensation expense recorded under the Purchase Plan during the years ended December 31, 2013, 2012 and 2011 was $0.8 million, $0.7 million and $0.7 million, respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2013
Leases [Abstract]	'
Leases	'
	Leases
	Office Space
	The Company's executive offices and those related to certain domestic product development, marketing, production and administration are located in a 107,000 square foot office facility in Canonsburg, Pennsylvania. In May 2004, the Company entered into the first amendment to its existing lease agreement on this facility, effective January 1, 2004. The lease was extended from its original period to a period through December 31, 2014. The Company incurred lease rental expense related to this facility of $1.3 million in each of the years ended December 31, 2013, 2012 and 2011. The minimum lease payments for this facility are $1.4 million for 2014.
	On September 14, 2012, the Company entered into a lease agreement for 186,000 square feet of rentable space to be located in a to-be-built office facility in Canonsburg, Pennsylvania, which will serve as the Company's new headquarters. The lease was effective as of September 14, 2012, but because the leased premises are under construction, the Company will not be obligated to pay rent until the later of (i) three months following the date that the leased premises are delivered to ANSYS, which delivery, subject to certain limited exceptions, shall occur no later than October 1, 2014, or (ii) January 1, 2015. The term of the lease is 183 months, beginning on the date the Company takes possession of the facility. Absent the exercise of options in the lease for additional rentable space or early lease termination, the Company's base rent will be $4.3 million per annum for the first five years of the lease term, $4.5 million per annum for years six through ten and $4.7 million per annum for years eleven through fifteen.
	The Company leases a 52,000 square foot office facility in San Jose, California that was acquired through the Apache acquisition. In June 2012, the Company entered into a new lease for this property, with the lease term commencing July 1, 2012 and ending June 30, 2022. Total remaining minimum payments under the operating lease as of December 31, 2013 are $8.4 million, of which $0.9 million will be paid in 2014.
	The Company has entered into various other noncancellable operating leases for office space.
	Office space lease expense totaled $14.1 million, $13.7 million and $12.8 million for the years ended December 31, 2013, 2012 and 2011, respectively. Future minimum lease payments under noncancellable operating leases for office space in effect at December 31, 2013 are $11.7 million in 2014, $10.8 million in 2015, $8.7 million in 2016, $7.2 million in 2017 and $6.6 million in 2018.
	Sale-Leaseback Arrangement
	The lease agreement terms for the new Canonsburg headquarters facility provide that the Company is responsible for paying the cost of certain tenant improvements that exceed an allowance to be paid by the landlord. There is no cap to the Company's obligation in excess of the landlord allowance, and the improvements do not meet the definition of "normal tenant improvements" as defined in the accounting guidance. As a result, the Company is considered the owner of the building during the construction period and the lease is subject to sale-leaseback treatment.
	As of December 31, 2013, the Company has recorded an $18.1 million construction-in-progress asset and a corresponding liability for construction debt funded by the lessor on its consolidated balance sheet. Upon completion and delivery of the building, the Company will determine whether the lease meets the criteria for capital treatment under the accounting guidance, or whether it has continuing involvement in the lease. If it is determined the lease fails to meet the capitalization criteria, and the Company does not have continuing involvement in the lease, the construction-in-progress asset and liability will be removed from the consolidated balance sheet. The sale-leaseback treatment of the lease during the construction period does not have any impact on the Company's results of operations or cash flows.

Royalty_Agreements

Royalty Agreements	12 Months Ended
	Dec. 31, 2013
Royalty Agreements [Abstract]	'
Royalty Agreements	'
	Royalty Agreements
	The Company has entered into various renewable, nonexclusive license agreements under which the Company has been granted access to the licensor’s technology and the right to sell the technology in the Company’s product line. Royalties are payable to developers of the software at various rates and amounts, which generally are based upon unit sales or revenue. Royalty fees are reported in cost of goods sold and were $10.3 million, $9.3 million and $8.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.

Geographic_Information_Notes

Geographic Information (Notes)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Geographic Information [Text Block]	'
	Geographic Information
	Revenue to external customers is attributed to individual countries based upon the location of the customer. Revenue by geographic area is as follows:
		Year Ended December 31,
	(in thousands)	2013		2012		2011
	United States	$	292,323	$	265,436	$	215,924
	Japan	108,064		122,437		112,171
	Germany	93,525		82,008		72,301
	Canada	14,163		12,384		12,069
	Other European	201,614		177,069		166,551
	Other international	151,571		138,684		112,433
	Total revenue	$	861,260	$	798,018	$	691,449
	Property and equipment by geographic area is as follows:
		December 31,
	(in thousands)	2013		2012
	United States	$	45,116	$	36,716
	India	3,226		3,392
	United Kingdom	3,016		3,532
	Germany	2,328		2,087
	France	2,275		2,378
	Japan	1,383		1,253
	Canada	618		753
	Other European	1,476		1,173
	Other international	1,100		969
	Total property and equipment	$	60,538	$	52,253
Geographic Information	'
	Property and equipment by geographic area is as follows:
		December 31,
	(in thousands)	2013		2012
	United States	$	45,116	$	36,716
	India	3,226		3,392
	United Kingdom	3,016		3,532
	Germany	2,328		2,087
	France	2,275		2,378
	Japan	1,383		1,253
	Canada	618		753
	Other European	1,476		1,173
	Other international	1,100		969
	Total property and equipment	$	60,538	$	52,253

Unconditional_Purchase_Obligat

Unconditional Purchase Obligations	12 Months Ended
	Dec. 31, 2013
Unconditional Purchase Obligations (Excluding Capital Stock Redemptions) [Abstract]	'
Unconditional Purchase Obligations	'
	Unconditional Purchase Obligations
	The Company has entered into various unconditional purchase obligations which primarily include software licenses and long-term purchase contracts for network, communication and office maintenance services. The Company expended $3.3 million, $4.0 million and $5.0 million related to unconditional purchase obligations that existed as of the beginning of each year for the years ended December 31, 2013, 2012 and 2011, respectively. Future expenditures under these obligations in effect as of December 31, 2013 are $2.9 million in 2014, $0.8 million in 2015 and $0.2 million in 2016.

Contingencies_and_Commitments_

Contingencies and Commitments (Notes)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Contingencies and Commitments	'
	Contingencies and Commitments
	The Company is subject to various investigations, claims and legal proceedings that arise in the ordinary course of business, including alleged infringement of intellectual property rights, commercial disputes, labor and employment matters, tax audits and other matters. In the opinion of the Company, the resolution of pending matters is not expected to have a material, adverse effect on the Company’s consolidated results of operations, cash flows or financial position. However, each of these matters is subject to various uncertainties and it is possible that an unfavorable resolution of one or more of these proceedings could materially affect the Company’s results of operations, cash flows or financial position.
	An Indian subsidiary of the Company received a formal inquiry after a service tax audit. The service tax issues raised in the Company’s notice are very similar to the case, M/s Microsoft Corporation (I) (P) Ltd. Vs Commissions of Service Tax, currently being appealed to the Delhi Customs, Excise and Service Tax Appellate Tribunal (CESTAT). If the ruling is in favor of Microsoft, the Company expects a similar outcome for its audit case. If the ruling is unfavorable in the case of Microsoft, the Company could incur tax charges and related liabilities, including those related to the service tax audit case, of $6 million. Of the two judicial members assigned to the Microsoft appeal, one member has ruled in favor of Microsoft and one has ruled in favor of the Commission. A third deciding judge will be appointed for a final decision. The Company can provide no assurances as to the outcome of the Microsoft appeal or to the impact of the Microsoft appeal on the Company’s audit case. The Company is uncertain as to when the service tax audit will be completed.
	The Company sells software licenses and services to its customers under proprietary software license agreements. Each license agreement contains the relevant terms of the contractual arrangement with the customer, and generally includes certain provisions for indemnifying the customer against losses, expenses and liabilities from damages that are incurred by or awarded against the customer in the event the Company’s software or services are found to infringe upon a patent, copyright or other proprietary right of a third party. To date, the Company has not had to reimburse any of its customers for any losses related to these indemnification provisions and no material claims asserted under these indemnification provisions are outstanding as of December 31, 2013. For several reasons, including the lack of prior material indemnification claims, the Company cannot determine the maximum amount of potential future payments, if any, related to such indemnification provisions.

Schedule_II_Valuation_and_Qual

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2013
Valuation and Qualifying Accounts [Abstract]	'
Valuation and Qualifying Accounts	'
	ANSYS, INC. AND SUBSIDIARIES
	Valuation and Qualifying Accounts
	(in thousands)	Balance  at		Additions–		Deductions–		Balance at
	Description	Beginning		Charges to Costs		Returns and		End
		of Year		and Expenses		Write-Offs		of Year
	Year ended December 31, 2013	$	4,800	$	1,465	$	565	$	5,700
	Allowance for doubtful accounts
	Year ended December 31, 2012	$	4,101	$	938	$	239	$	4,800
	Allowance for doubtful accounts
	Year ended December 31, 2011	$	4,503	$	404	$	806	$	4,101
	Allowance for doubtful accounts

Summary_Of_Significant_Account

Summary Of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Accounting Principles	'
	The financial statements and accompanying notes are prepared in accordance with accounting principles generally accepted in the United States.
Principles Of Consolidation	'
	The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated.
Use Of Estimates	'
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. Estimates also affect the amounts of revenue and expenses during the reported periods. Significant estimates included in these consolidated financial statements include:
	•	Allowances for doubtful accounts receivable
	•	Income tax accruals
	•	Uncertain tax positions
	•	Tax valuation reserves
	•	Fair value of stock-based compensation
	•	Contract revenue
	•	Useful lives for depreciation and amortization
	•	Valuations of goodwill and other intangible assets
	•	Contingent consideration
	•	Deferred compensation
	•	Loss contingencies
	Actual results could differ from these estimates. Changes in estimates are recorded in the results of operations in the period that the changes occur.
Revenue Recognition	'
	Revenue is derived principally from the licensing of computer software products and from related maintenance contracts. Revenue from perpetual licenses is classified as license revenue and is recognized upon delivery of the licensed product and the utility that enables the customer to access authorization keys, provided that acceptance has occurred and a signed contractual obligation has been received, the price is fixed and determinable, and collectibility of the receivable is probable. The Company determines the fair value of PCS sold together with perpetual licenses based on the rate charged for PCS when sold separately. Revenue from PCS contracts is classified as maintenance and service revenue and is recognized ratably over the term of the contract.
	Revenue for software lease licenses is classified as license revenue and is recognized over the period of the lease contract. Typically, the Company’s software leases include PCS which, due to the short term (principally one year or less) of the Company’s software lease licenses, cannot be separated from lease revenue for accounting purposes. As a result, both the lease license and PCS are recognized ratably over the lease period. Due to the short-term nature of the software lease licenses and the frequency with which the Company provides major product upgrades (typically every 12–18 months), the Company does not believe that a significant portion of the fee paid under the arrangement is attributable to the PCS component of the arrangement and, as a result, includes the revenue for the entire arrangement within software license revenue in the consolidated statements of income.
	The Company's Apache products are typically licensed via longer term leases of 24–36 months.  The Company recognizes revenue for these licenses over the term of the lease contract.  Because the Company does not have vendor-specific objective evidence of the fair value of these leases, the Company also recognizes revenue from perpetual licenses over the term of the lease contract during the infrequent occurrence of these licenses being sold with Apache leases in multiple-element arrangements.
	Revenue from training, support and other services is recognized as the services are performed. The Company applies the specific performance method to contracts in which the service consists of a single act, such as providing a training class to a customer, and the proportional performance method to other service contracts that are longer in duration and often include multiple acts (for example, both training and consulting). In applying the proportional performance method, the Company typically utilizes output-based estimates for services with contractual billing arrangements that are not based on time and materials, and estimates output based on the total tasks completed as compared to the total tasks required for each work contract. Input-based estimates are utilized for services that involve general consultations with contractual billing arrangements based on time and materials, utilizing direct labor as the input measure.
	The Company also executes arrangements through independent channel partners in which the channel partners are authorized to market and distribute the Company’s software products to end-users of the Company’s products and services in specified territories. In sales facilitated by channel partners, the channel partner bears the risk of collection from the end-user customer. The Company recognizes revenue from transactions with channel partners when the channel partner submits a written purchase commitment, collectibility from the channel partner is probable, a signed license agreement is received from the end-user customer and delivery has occurred, provided that all other revenue recognition criteria are satisfied. Revenue from channel partner transactions is the amount remitted to the Company by the channel partners. This amount includes a fee for PCS that is compensation for providing technical enhancements and the second level of technical support to the end-user, which is based on the rate charged for PCS when sold separately, and is recognized over the period that PCS is to be provided. The Company does not offer right of return, product rotation or price protection to any of its channel partners.
	Non-income related taxes collected from customers and remitted to governmental authorities are recorded on the consolidated balance sheet as accounts receivable and accrued expenses. The collection and payment of these amounts are reported on a net basis in the consolidated statements of income and do not impact reported revenues or expenses.
	The Company warrants to its customers that its software will substantially perform as specified in the Company’s most current user manuals. The Company has not experienced significant claims related to software warranties beyond the scope of maintenance support, which the Company is already obligated to provide, and consequently the Company has not established reserves for warranty obligations.
Cash And Cash Equivalents	'
	Cash and cash equivalents consist primarily of highly liquid investments such as deposits held at major banks and money market mutual funds with original maturities of three months or less. Cash equivalents are carried at cost, which approximates fair value. The Company’s cash and cash equivalents balances comprise the following:
		31-Dec-13					31-Dec-12
	(in thousands, except percentages)	Amount			% of Total		Amount				% of Total
	Cash accounts	$	439,348		59.2		$	369,724			64.1
	Money market mutual funds	303,138			40.8		206,979				35.9
	Total	$	742,486				$	576,703
	The Company held 99% and 98% of its money market mutual fund balances in various funds of a single issuer as of December 31, 2013 and December 31, 2012, respectively.
Short-Term Investments	'
	Short-term investments consist primarily of deposits held by certain foreign subsidiaries of the Company with original maturities of three months to one year. The Company considers investments backed by government agencies or financial institutions with maturities of less than one year to be highly liquid and classifies such investments as short-term investments. Short-term investments are recorded at fair value. The Company uses the specific identification method to determine the realized gain or loss upon the sale of such securities.
	The Company is averse to principal loss and seeks to preserve invested funds by limiting default risk, market risk and reinvestment risk by placing its investments with high-quality credit issuers.
Property And Equipment	'
	Property and equipment is stated at cost. Depreciation is computed on the straight-line method over the estimated useful lives of the various classes of assets, which range from one to 40 years. Repairs and maintenance are charged to expense as incurred. Gains or losses from the sale or retirement of property and equipment are included in operating income.
Research And Development Costs	'
	Research and development costs, other than certain capitalized software development costs, are expensed as incurred.
Capitalized Software	'
	Internally developed software costs required to be capitalized as defined by the accounting guidance were not material to the Company's consolidated financial statements in 2013, 2012 and 2011.
Business Combinations Policy [Policy Text Block]	'
	When the Company consummates an acquisition, the assets acquired and the liabilities assumed are recognized separately from goodwill, at their acquisition date fair values. Goodwill as of the acquisition date is measured as the excess of the fair value of consideration transferred over the net of the acquisition date fair values of the assets acquired and the liabilities assumed. While best estimates and assumptions are used to accurately value assets acquired and liabilities assumed at the acquisition date as well as contingent consideration, where applicable, the Company's estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company records adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill based on refinements to information regarding what was known and knowable as of the acquisition date. Upon the earlier of the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, any subsequent adjustments are recorded in the consolidated statements of income.
Goodwill And Other Intangible Assets	'
	Goodwill represents the excess of the consideration transferred over the fair value of net identifiable assets acquired. Other intangible assets consist of trademarks, customer lists, contract backlog, and acquired software and technology. Intangible assets that are not considered to have an indefinite useful life are amortized over their useful lives, which are generally three to 15 years. Amortization expense for intangible assets was $60.7 million, $67.3 million and $51.7 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	The Company tests goodwill and indefinite-lived intangible assets for impairment at least annually by performing a qualitative assessment of whether there is sufficient evidence that it is more likely than not that the fair value of each reporting unit or asset exceeds its carrying amount. Goodwill is tested at the reporting unit level and indefinite-lived intangible assets are tested at the individual asset level. The application of a qualitative assessment requires the Company to assess and make judgments regarding a variety of factors which potentially impact the fair value of the reporting unit or asset being tested, including general economic conditions, industry and market-specific conditions, customer behavior, cost factors, the Company's financial performance and trends, the Company's strategies and business plans, capital requirements, management and personnel issues, and the Company's stock price, among others. The Company then considers the totality of these and other factors, placing more weight on the events and circumstances that are judged to most affect the reporting unit's or asset's fair value and carrying amount, to reach a qualitative conclusion regarding whether it is more likely than not that the fair value of a reporting unit or asset is less than its carrying amount.
	If it is determined that it is more likely than not that the fair value of a reporting unit or asset exceeds its carrying value, no further analysis is necessary. If it is determined that it is more likely than not the reporting unit's or asset's carrying value exceeds its fair value, a quantitative two-step analysis is performed where the fair value of the reporting unit or asset is estimated and the impairment loss, if any, is recorded.
	The Company performs its annual impairment tests for goodwill and indefinite-lived intangible assets on January 1 of each year unless there is an indicator that would require a test during the year. The Company periodically reviews the carrying value of other intangible assets and will recognize impairments when events or circumstances indicate that such assets may be impaired.
Concentrations Of Credit Risk	'
	The Company has a concentration of credit risk with respect to revenue and trade receivables due to the use of certain significant channel partners to market and sell the Company’s products. The Company performs periodic credit evaluations of its customers’ financial condition and generally does not require collateral. The following table outlines concentrations of risk with respect to the Company’s revenue:
			Year Ended December 31,
	(as a % of revenue, except customer data)		2013		2012			2011
	Revenue from channel partners		25	%	26	%		26	%
	Largest channel partner		6	%	6	%		4	%
	2nd largest channel partner		2	%	3	%		3	%
	No single direct sale customer accounted for more than 5% of the Company's revenue in 2013, 2012 or 2011.
	In addition to the concentration of credit risk with respect to trade receivables, the Company’s cash and cash equivalents are also exposed to concentration of credit risk. The Company's cash and cash equivalent accounts are insured through various public and private bank deposit insurance programs, foreign and domestic; however, a significant portion of the Company's funds are not insured. The following table outlines concentrations of risk with respect to the Company's cash and cash equivalents:
		As of December 31,
	(in thousands)	2013			2012
	Cash and cash equivalents held domestically	$	530,680		$	399,295
	Cash and cash equivalents held by foreign subsidiaries	211,806			177,408
	Cash and cash equivalents held in excess of deposit insurance, foreign and domestic	717,589			559,023
	Cash and cash equivalents held with one U.S. financial institution, foreign and domestic	378,562			296,270
Allowance For Doubtful Accounts	'
	The Company makes judgments as to its ability to collect outstanding receivables and provides allowances for a portion of receivables when collection becomes doubtful. Provisions are made based upon a specific review of all significant outstanding invoices from both value and delinquency perspectives. For those invoices not specifically reviewed, provisions are provided at differing rates based upon the age of the receivable and the geographic area of origin. In determining these percentages, the Company considers its historical collection experience and current economic trends in the customer’s industry and geographic region. The Company recorded provisions for doubtful accounts of $1.5 million, $0.9 million and $0.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.
Income Taxes	'
	The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period of the enactment date.
	The Company records net deferred tax assets to the extent it believes these assets will more likely than not be realized. In making such determination, the Company considers all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial operations. In the event the Company determines that it will be able to realize deferred income tax assets in the future in excess of their net recorded amount, an adjustment to the valuation allowance would be recorded that would reduce the provision for income taxes.
	Tax benefits related to uncertain tax positions taken or expected to be taken on a tax return are recorded when such benefits meet a more likely than not threshold. Otherwise, these tax benefits are recorded when a tax position has been effectively settled, which means that the statute of limitations has expired or the appropriate taxing authority has completed their examination even though the statute of limitations remains open. The Company recognizes interest and penalties related to unrecognized tax benefits within the income tax expense line in the accompanying consolidated statements of income. Accrued interest and penalties are included within the related tax liability line in the consolidated balance sheets.
Foreign Currencies	'
	Certain of the Company’s sales and intercompany transactions are denominated in foreign currencies. These transactions are translated to the functional currency at the exchange rate on the transaction date. Assets and liabilities denominated in a currency other than the Company's or subsidiary's functional currency are translated at the effective exchange rate on the balance sheet date. Gains and losses resulting from foreign exchange transactions are included in other expense. The Company recorded net foreign exchange losses of $1.1 million, $1.4 million and $0.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	The financial statements of the Company’s foreign subsidiaries are translated from the functional (local) currency to U.S. Dollars. Assets and liabilities are translated at the exchange rates on the balance sheet date. Results of operations are translated at average exchange rates, which approximate rates in effect when the underlying transactions occur.
Accumulated Other Comprehensive Income	'
	Accumulated other comprehensive income is composed entirely of foreign currency translation adjustments.
Earnings Per Share	'
	Basic earnings per share ("EPS") amounts are computed by dividing earnings by the weighted average number of common shares outstanding during the period. Diluted EPS amounts assume the issuance of common stock for all potentially dilutive equivalents outstanding. To the extent stock options are anti-dilutive, they are excluded from the calculation of diluted EPS. The details of basic and diluted EPS are as follows:
			Year Ended December 31,
	(in thousands, except per share data)		2013			2012				2011
	Net income		$	245,327		$	203,483			$	180,675
	Weighted average shares outstanding – basic		92,691			92,622				92,120
	Dilutive effect of stock plans		2,448			2,332				2,261
	Weighted average shares outstanding – diluted		95,139			94,954				94,381
	Basic earnings per share		$	2.65		$	2.2			$	1.96
	Diluted earnings per share		$	2.58		$	2.14			$	1.91
	Anti-dilutive options		885			1,506				1,421
Stock-Based Compensation	'
	The Company accounts for stock-based compensation in accordance with share-based payment accounting guidance. The guidance requires an entity to measure the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award. The cost is recognized over the period during which an employee is required to provide service in exchange for the award, typically the vesting period.
Fair Value Of Financial Instruments	'
	The Company accounts for certain assets and liabilities at fair value in accordance with the accounting guidance applicable to fair value measurements and disclosures. The carrying values of cash, cash equivalents, accounts receivable, accounts payable, accrued expenses, other accrued liabilities and short-term obligations are deemed to be reasonable estimates of their fair values because of their short-term nature. The fair values of investments are based on quoted market prices for those or similar investments.

Summary_Of_Significant_Account1

Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Summary Of Cash And Cash Equivalents	'
	The Company’s cash and cash equivalents balances comprise the following:
		31-Dec-13					31-Dec-12
	(in thousands, except percentages)	Amount			% of Total		Amount				% of Total
	Cash accounts	$	439,348		59.2		$	369,724			64.1
	Money market mutual funds	303,138			40.8		206,979				35.9
	Total	$	742,486				$	576,703
Schedule Of Risk Concentration	'
	The following table outlines concentrations of risk with respect to the Company’s revenue:
			Year Ended December 31,
	(as a % of revenue, except customer data)		2013		2012			2011
	Revenue from channel partners		25	%	26	%		26	%
	Largest channel partner		6	%	6	%		4	%
	2nd largest channel partner		2	%	3	%		3	%
Basic And Diluted Earnings Per Share	'
	The details of basic and diluted EPS are as follows:
			Year Ended December 31,
	(in thousands, except per share data)		2013			2012				2011
	Net income		$	245,327		$	203,483			$	180,675
	Weighted average shares outstanding – basic		92,691			92,622				92,120
	Dilutive effect of stock plans		2,448			2,332				2,261
	Weighted average shares outstanding – diluted		95,139			94,954				94,381
	Basic earnings per share		$	2.65		$	2.2			$	1.96
	Diluted earnings per share		$	2.58		$	2.14			$	1.91
	Anti-dilutive options		885			1,506				1,421

Accounting_Policies_Cash_And_C

Accounting Policies Cash And Cash Equivalents Concentrations of Risk (Tables)	12 Months Ended
	Dec. 31, 2013
Cash and Cash Equivalents [Line Items]	'
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	'
	The following table outlines concentrations of risk with respect to the Company’s revenue:
			Year Ended December 31,
	(as a % of revenue, except customer data)		2013		2012		2011
	Revenue from channel partners		25	%	26	%	26	%
	Largest channel partner		6	%	6	%	4	%
	2nd largest channel partner		2	%	3	%	3	%
Concentration Risk Type [Domain]	'
Cash and Cash Equivalents [Line Items]	'
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	'
	The following table outlines concentrations of risk with respect to the Company's cash and cash equivalents:
		As of December 31,
	(in thousands)	2013			2012
	Cash and cash equivalents held domestically	$	530,680		$	399,295
	Cash and cash equivalents held by foreign subsidiaries	211,806			177,408
	Cash and cash equivalents held in excess of deposit insurance, foreign and domestic	717,589			559,023
	Cash and cash equivalents held with one U.S. financial institution, foreign and domestic	378,562			296,270

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2013
Esterel Technologies, S.A.	'
Business Acquisition [Line Items]	'
Fair Value of Consideration Transferred	'
	r Value of Consideration Transferred:
	(in thousands)
	Cash	$	58,150
	Re
Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed	'
	ognized Amounts of Identifiable Assets Acquired and Liabilities Assumed:
	(dollars in thousands)
	Cash	$	13,075
	Accounts receivable and other tangible assets	4,737
	Customer relationships (12-year life)	21,421
	Developed software (10-year life)	10,717
	Platform trade name (indefinite life)	2,695
	Accounts payable and other liabilities	(4,707		)
	Deferred revenue	(1,139		)
	Net deferred tax liabilities	(7,096		)
	Total identifiable net assets	$	39,703
	Goodwill	$	18,447
	Th
Apache Design Inc [Member]	'
Business Acquisition [Line Items]	'
Fair Value of Consideration Transferred	'
	r Value of Consideration Transferred:
	(in thousands)
	Cash	$	301,306
	Contingent consideration	9,501
	ANSYS replacement stock options	3,170
	Total consideration transferred at fair value	$	313,977
	Re
Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed	'
	ognized Amounts of Identifiable Assets Acquired and Liabilities Assumed:
	(dollars in thousands)
	Cash and short-term investments	$	31,948
	Accounts receivable and other tangible assets	6,011
	Developed software (7-year life)	82,500
	Customer relationships (15-year life)	36,100
	Contract backlog (3-year life)	13,500
	Platform trade names (indefinite lives)	21,900
	Apache trade name (6-year life)	2,100
	Accounts payable and other liabilities	(16,867		)
	Deferred revenue	(10,100		)
	Net deferred tax liabilities	(47,229		)
	Total identifiable net assets	$	119,863
	Goodwill	$	194,114
	Th

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Components Of Property and Equipment	'
	Property and equipment consists of the following:
			December 31,
	(dollars in thousands)	Estimated Useful Lives	2013			2012
	Equipment	1-10 years	$	68,970		$	59,580
	Computer software	1-5 years	27,647			26,864
	Buildings	10-40 years	24,325			15,122
	Leasehold improvements	1-10 years	8,125			7,334
	Furniture	1-10 years	4,973			4,457
	Land		2,178			2,178
			136,218			115,535
	Less: Accumulated depreciation and amortization		(75,680		)	(63,282		)
			$	60,538		$	52,253

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Intangible Assets and Estimated Useful Lives	'
	The Company’s intangible assets and estimated useful lives are classified as follows:
		31-Dec-13						31-Dec-12
	(dollars in thousands)	Gross			Accumulated			Gross		Accumulated
		Carrying			Amortization			Carrying		Amortization
		Amount						Amount
	Finite-lived intangible assets:
	Developed software and core technologies (5 – 10 years)	$	300,493		$	(203,236	)	$	298,802	$	(175,988	)
	Customer lists and contract backlog (3 – 15 years)	237,173			(119,368		)	241,721		(100,702		)
	Trade names (6 – 10 years)	102,651			(50,990		)	102,629		(40,436		)
	Total	$	640,317		$	(373,594	)	$	643,152	$	(317,126	)
	Indefinite-lived intangible assets:
	Trade names	$	24,667					$	25,147
Estimated Future Amortization Expense for Intangible Assets	'
	As of December 31, 2013, estimated future amortization expense for the intangible assets reflected above is as follows:
	(in thousands)
	2014	$	54,119
	2015	50,482
	2016	43,374
	2017	39,604
	2018	25,982
	Thereafter	53,162
	Total intangible assets subject to amortization	266,723
	Indefinite-lived trade names	24,667
	Other intangible assets, net	$	291,390
Changes in Goodwill	'
	The changes in goodwill during the years ended December 31, 2013 and 2012 are as follows:
	(in thousands)	2013			2012
	Beginning balance - January 1	$	1,251,247		$	1,225,375
	Acquisitions of EVEN and Esterel, respectively	5,936			20,866
	Currency translation and other	(1,479		)	5,006
	Ending balance - December 31	$	1,255,704		$	1,251,247

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Interest Expense on Term Loan and Amortization Related to Debt Financing Costs	'
	The interest expense on the term loan and amortization related to debt financing costs are as follows:
		Year Ended December 31,
		2013				2012				2011
	(in thousands)	Interest		Amortization		Interest		Amortization		Interest		Amortization
		Expense				Expense				Expense
	July 31, 2008 term loan	$	230	$	149	$	1,342	$	698	$	1,605	$	953

Fair_Value_Measurement_Tables

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Assets and Liabilities Measured on Recurring Basis	'
	The following tables provide the assets and liabilities carried at fair value and measured on a recurring basis:
					Fair Value Measurements at Reporting Date Using:
	(in thousands)	31-Dec-13			Quoted Prices in			Significant Other			Significant
					Active Markets			Observable			Unobservable
					(Level 1)			Inputs			Inputs
								(Level 2)			(Level 3)
	Assets
	Cash equivalents	$	303,138		$	303,138		$	—		$	—
	Short-term investments	$	500		$	—		$	500		$	—
	Liabilities
	Contingent consideration	$	(7,389	)	$	—		$	—		$	(7,389	)
	Deferred compensation	$	(704	)	$	—		$	—		$	(704	)
					Fair Value Measurements at Reporting Date Using:
	(in thousands)	31-Dec-12			Quoted Prices in			Significant Other			Significant
					Active Markets			Observable			Unobservable
					(Level 1)			Inputs			Inputs
								(Level 2)			(Level 3)
	Assets
	Cash equivalents	$	206,979		$	206,979		$	—		$	—
	Short-term investments	$	452		$	—		$	452		$	—
	Liabilities
	Contingent consideration	$	(6,436	)	$	—		$	—		$	(6,436	)
	Deferred compensation	$	(1,394	)	$	—		$	—		$	(1,394	)
	Foreign currency future	$	(240	)	$	—		$	(240	)	$	—
Changes in Level 3 Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs	'
	The following table presents the changes during the years ended December 31, 2013 and 2012 in the Company’s Level 3 liabilities for contingent consideration and deferred compensation that are measured at fair value on a recurring basis:
		Fair Value Measurement Using
		Significant Unobservable Inputs
	(in thousands)	Contingent			Deferred
		Consideration			Compensation
	Balance as of January 1, 2012	$	9,571		$	2,073
	Contingent payments	(3,288		)	(712		)
	Interest expense included in earnings	153			33
	Balance as of December 31, 2012	$	6,436		$	1,394
	EVEN contingent consideration	3,597			—
	Contingent payments	(3,288		)	(712		)
	Interest expense and foreign exchange activity included in earnings	644			22
	Balance as of December 31, 2013	$	7,389		$	704

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Components Of Income Before Income Taxes	'
	Income before income taxes includes the following components:
		Year Ended December 31,
	(in thousands)	2013				2012				2011
	Domestic	$	272,569			$	234,497			$	205,966
	Foreign	49,920				59,050				58,892
	Total	$	322,489			$	293,547			$	264,858
Components Of Provision For Income Taxes	'
	The provision for income taxes is composed of the following:
		Year Ended December 31,
	(in thousands)	2013				2012				2011
	Current:
	Federal	$	69,268			$	79,028			$	57,423
	State	7,197				7,886				5,770
	Foreign	24,722				22,046				24,011
	Deferred:
	Federal	(23,438		)		(21,026		)		(11,768		)
	State	(2,187		)		(3,913		)		(1,314		)
	Foreign	1,600				6,043				10,061
	Total	$	77,162			$	90,064			$	84,183
Reconciliation Of U.S. Federal Statutory Tax Rate To Consolidated Effective Tax Rate	'
	The reconciliation of the U.S. federal statutory tax rate to the consolidated effective tax rate is as follows:
		Year Ended December 31,
		2013			2012			2011
	Federal statutory tax rate	35	%		35	%		35	%
	State income taxes, net of federal benefit	1.1			1.2			1.1
	Stock-based compensation	0.9			1			1
	Changes in tax rates	0.3			0.8			2.2
	Net (benefit) tax of unrepatriated earnings	(0.9	)		0.7			—
	Uncertain tax positions	(3.7	)		0.3			0.2
	Research and experimentation credits	(2.0	)		(0.1	)		(0.9	)
	Adjustments of prior year taxes	(0.1	)		(1.3	)		(0.3	)
	Foreign rate differential	(0.9	)		(1.9	)		(1.1	)
	Benefit from restructuring activities	(2.8	)		(3.1	)		(3.5	)
	Domestic production activity benefit	(3.3	)		(3.3	)		(2.9	)
	Other	0.3			1.4			1
		23.9	%		30.7	%		31.8	%
Components Of Deferred Tax Assets And Liabilities	'
	The components of deferred tax assets and liabilities are as follows:
		December 31,
	(in thousands)	2013				2012
	Deferred tax assets:
	Net operating loss carryforwards	$	26,204			$	26,228
	Employee benefits	18,824				17,670
	Stock-based compensation	20,006				16,092
	Foreign tax credits	403				558
	Other accruals not currently deductible	1,165				1,207
	Research and development credits	2,331				2,254
	Uncertain tax positions	7,977				7,790
	Deferred revenue	7,816				5,139
	Allowance for doubtful accounts	2,014				1,661
	Other	1,953				2,227
	Valuation allowance	(392		)		(14		)
		88,301				80,812
	Deferred tax liabilities:
	Other intangible assets	(106,115		)		(128,671		)
	Property and equipment	(4,556		)		(5,838		)
	Unremitted foreign earnings	(115		)		(2,204		)
		(110,786		)		(136,713		)
	Net deferred tax liabilities	$	(22,485	)		$	(55,901	)
Reconciliation Of Unrecognized Tax Benefits	'
	The following is a reconciliation of the total amounts of unrecognized tax benefits:
		Year Ended December 31,
	(in thousands)	2013				2012				2011
	Unrecognized tax benefit as of January 1	$	37,203			$	31,582			$	19,993
	Acquired unrecognized tax benefit	—				3,845				5,813
	Gross increases—tax positions in prior period	320				2,048				6,814
	Gross decreases—tax positions in prior period	(18,058		)		(2,167		)		(2,697		)
	Gross increases—tax positions in current period	2,036				2,660				2,297
	Reductions due to a lapse of the applicable statute of limitations	(1,734		)		(1,314		)		(190		)
	Changes due to currency fluctuation	20				625				(448		)
	Settlements	(197		)		(76		)		—
	Unrecognized tax benefit as of December 31	$	19,590			$	37,203			$	31,582

Stock_Option_And_Grant_Plan_Ta

Stock Option And Grant Plan (Tables)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Summary Of Stock Options	'
	Information regarding stock option transactions is summarized below:
			Year Ended December 31,
			2013							2012							2011
	(options in thousands)		Options			Weighted				Options			Weighted				Options		Weighted
						Average							Average						Average
						Exercise							Exercise						Exercise
						Price							Price						Price
	Outstanding, beginning of year		7,122			$	42.85			7,545			$	35.1			7,319		$	29.92
	Granted		103			$	81.87			1,109			$	67.53			1,104		$	58.5
	Issued pursuant to Apache acquisition		—			$	—			—			$	—			418		$	18.66
	Exercised		(993	)		$	34.26			(1,464	)		$	21.85			(1,179	)	$	19.33
	Forfeited		(66	)		$	53.75			(68	)		$	36.9			(117	)	$	33.27
	Outstanding, end of year		6,166			$	44.77			7,122			$	42.85			7,545		$	35.1
	Vested and Exercisable, end of year		4,351			$	38.18			4,094			$	33.91			4,251		$	27.98
			2013				2012				2011
	Weighted Average Remaining Contractual Term (in years)
	Outstanding		5.99				6.78				6.66
	Vested and Exercisable		5.13				5.48				5.2
	Aggregate Intrinsic Value (in thousands)
	Outstanding		$	261,601			$	174,383			$	168,837
	Vested and Exercisable		$	213,304			$	136,851			$	124,550
Stock-Based Compensation Expense	'
	Total stock-based compensation expense recognized for the years ended December 31, 2013, 2012 and 2011 is as follows:
			Year Ended December 31,
	(in thousands, except per share amounts)		2013				2012				2011
	Cost of sales:
	Software licenses		$	1,349			$	1,478			$	556
	Maintenance and service		2,293				2,232				1,897
	Operating expenses:
	Selling, general and administrative		16,847				15,278				12,501
	Research and development		14,809				13,427				8,134
	Stock-based compensation expense before taxes		35,298				32,415				23,088
	Related income tax benefits		(11,096		)		(8,509		)		(5,552		)
	Stock-based compensation expense, net of taxes		$	24,202			$	23,906			$	17,536
	Net impact on earnings per share:
	Basic earnings per share		$	(0.26	)		$	(0.26	)		$	(0.19	)
	Diluted earnings per share		$	(0.25	)		$	(0.25	)		$	(0.19	)
Information Regarding Stock Options Outstanding	'
	Information regarding stock options outstanding as of December 31, 2013 is summarized below:
	(options in thousands)		Options Outstanding									Options Exercisable
	Range of Exercise Prices		Options			Weighted		Weighted				Options			Weighted
						Average		Average							Average
						Remaining		Exercise							Exercise
						Contractual		Price							Price
						Life (years)
	$5.91 - $28.40		1,747			3.64		$	22.4			1,662			$	22.44
	$29.97 - $40.89		1,272			4.79		$	39.54			1,269			$	39.53
	$41.33 - $58.67		1,983			7.2		$	53.73			1,170			$	52.77
	$60.49 - $88.35		1,164			8.64		$	68.8			250			$	67.55
Stock Options [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Assumptions To Estimate Fair Value Of Stock Awards	'
	The table below presents the weighted average input assumptions used and resulting fair values for options granted or issued in business combinations during each respective year:
			Year Ended December 31,
			2013		2012		2011
	Risk-free interest rate		0.68% to 1.48%		0.59% to 1.04%		0.91% to 2.11%
	Expected dividend yield		—%		—%		—%
	Expected volatility		37%		38%		39%
	Expected term		5.8 years		6.0 years		5.8 years
	Weighted average fair value per share		$29.85		$24.82		$25.84
Restricted Stock Units (RSUs) [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Assumptions To Estimate Fair Value Of Stock Awards	'
		Year Ended December 31,
	Assumption used in Monte Carlo lattice pricing model	2013		2012		2011
	Risk-free interest rate	0.35%		0.16%		1.35%
	Expected dividend yield	—%		—%		—%
	Expected volatility—ANSYS Stock Price	25%		28%		40%
	Expected volatility—NASDAQ Composite Index	20%		20%		25%
	Expected term	2.8 years		2.8 years		2.9 years
	Correlation factor	0.7		0.75		0.7

Geographic_Information_Tables

Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area	'
	Revenue by geographic area is as follows:
		Year Ended December 31,
	(in thousands)	2013		2012		2011
	United States	$	292,323	$	265,436	$	215,924
	Japan	108,064		122,437		112,171
	Germany	93,525		82,008		72,301
	Canada	14,163		12,384		12,069
	Other European	201,614		177,069		166,551
	Other international	151,571		138,684		112,433
	Total revenue	$	861,260	$	798,018	$	691,449
Geographic Information	'
	Property and equipment by geographic area is as follows:
		December 31,
	(in thousands)	2013		2012
	United States	$	45,116	$	36,716
	India	3,226		3,392
	United Kingdom	3,016		3,532
	Germany	2,328		2,087
	France	2,275		2,378
	Japan	1,383		1,253
	Canada	618		753
	Other European	1,476		1,173
	Other international	1,100		969
	Total property and equipment	$	60,538	$	52,253

Organization_Additional_Inform

Organization - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2013
	Segment
Disclosure Organization Additional Information [Abstract]	'
Number of operating segments	2

Summary_Of_Significant_Account2

Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Amortization	$60,700,000	$67,300,000	$51,700,000
Amortization expense related to software costs	38,298,000	40,889,000	33,728,000
Provisions for doubtful accounts	1,465,000	938,000	404,000
Net foreign exchange losses	$1,100,000	$1,400,000	$400,000
Minimum [Member]	'	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Frequency period of major product upgrades (months)	'12 months	'	'
Property and equipment, estimated useful lives (years)	'1 year	'	'
Maximum [Member]	'	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Frequency period of major product upgrades (months)	'18 months	'	'
Property and equipment, estimated useful lives (years)	'40 years	'	'
Customer Concentration Risk [Member]	'	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Number Of Customers With More Than Five percent Of Revenue	0	0	0
Money Market Funds [Member] | Cash and Cash Equivalents [Member]	'	'	'
Summary Of Significant Accounting Policies [Line Items]	'	'	'
Concentration Risk, Percentage	99.00%	98.00%	'

Summary_Of_Significant_Account3

Summary Of Significant Accounting Policies (Summary Of Cash And Cash Equivalents) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Accounting Policies [Abstract]	'	'	'	'
Cash accounts	$439,348	$369,724	'	'
Money market mutual funds	303,138	206,979	'	'
Cash and cash equivalents	$742,486	$576,703	$471,828	$472,479
Cash accounts, % of Total	59.20%	64.10%	'	'
Money market mutual funds, % of Total	40.80%	35.90%	'	'

Summary_Of_Significant_Account4

Summary Of Significant Accounting Policies (Schedule Of Risk Concentration) (Details) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

In Thousands, unless otherwise specified

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

1st Largest Channel Partner [Member]

1st Largest Channel Partner [Member]

1st Largest Channel Partner [Member]

2nd Largest Channel Partner [Member]

2nd Largest Channel Partner [Member]

2nd Largest Channel Partner [Member]

UNITED STATES

UNITED STATES

Foreign [Member]

Foreign [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Concentration Risk [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash and Cash Equivalents, at Carrying Value

$742,486

$576,703

$471,828

$472,479

'

'

'

'

'

'

'

'

'

$530,680

$399,295

$211,806

$177,408

Revenue from channel partners

'

'

'

'

25.00%

26.00%

26.00%

6.00%

6.00%

4.00%

2.00%

3.00%

3.00%

'

'

'

'

Direct sale customers exceeding 5% of revenue

'

'

'

'

0

0

0

'

'

'

'

'

'

'

'

'

'

Cash and cash equivalents held in excess of deposit insurance, foreign and domestic

717,589

559,023

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash and cash equivalents held with one U.S. financial institution, foreign and domestic

$378,562

$296,270

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Summary_Of_Significant_Account5

Summary Of Significant Accounting Policies (Basic And Diluted Earnings Per Share) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]	'	'	'
Net income	$245,327	$203,483	$180,675
Weighted average shares outstanding - basic	92,691	92,622	92,120
Dilutive effect of stock plans	2,448	2,332	2,261
Weighted average shares outstanding - diluted	95,139	94,954	94,381
Basic earnings per share (in USD per share)	$2.65	$2.20	$1.96
Diluted earnings per share (in USD per share)	$2.58	$2.14	$1.91
Anti-dilutive options	885	1,506	1,421

Acquisition_Additional_Informa

Acquisition - Additional Information (Detail) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Aug. 01, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Jan. 03, 2014

Apr. 03, 2013

Aug. 01, 2011

Aug. 01, 2012

Dec. 31, 2013

Aug. 01, 2013

Apache Performance Restricted Stock Units

Apache Performance Restricted Stock Units

Reaction Design [Member]

EVEN-Evolutionary Engineering Aktiengesellschaft [Member]

Apache Design Inc [Member]

Esterel Technologies, S.A.

Esterel Technologies, S.A.

Esterel Technologies, S.A.

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Business acquisition, acquisition percentage

'

'

'

'

'

'

'

100.00%

100.00%

'

'

100.00%

Total consideration transferred at fair value

'

'

'

'

'

'

$19,000,000

$8,100,000

$313,977,000

$58,150,000

'

'

Payments to Acquire Businesses, Gross

'

'

'

'

'

'

'

4,500,000

301,306,000

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents

'

'

'

'

'

'

'

'

31,948,000

13,075,000

'

'

Acquired deferred revenue, amount lower than the historical carrying value recorded on the opening balance sheet

'

'

'

'

'

'

'

'

'

-10,973,000

'

'

Acquired deferred revenue, impact on reported revenue

'

'

'

'

'

'

'

'

'

'

4,136,000

'

Acquired deferred revenue, expected impact on reported revenue in next quarter

'

'

'

'

'

'

'

'

'

'

390,000

'

Acquired deferred revenue, expected impact on reported revenue in next fiscal year

'

'

'

'

'

'

'

'

'

'

1,408,000

'

ANSYS replacement stock options

'

'

'

'

'

'

'

'

3,170,000

'

'

'

Business Combination, Contingent Consideration, Liability

'

'

'

'

'

'

'

3,600,000

-9,501,000

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue

'

'

'

'

'

'

'

'

10,100,000

1,139,000

'

'

Business acquisition, potential performance equity awards

'

'

'

'

13,000,000

'

'

'

'

'

'

'

Value of each restricted stock unit on grant date

'

'

'

'

$50.30

'

'

'

'

'

'

'

Stock-based compensation expense

'

'

'

'

3,800,000

3,900,000

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent

'

'

10,000,000

'

'

'

'

'

-47,229,000

-7,096,000

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill

'

'

'

'

'

'

'

2,600,000

'

'

'

'

Goodwill

$1,255,704,000

$1,251,247,000

'

$1,225,375,000

'

'

'

$5,900,000

$194,114,000

$18,447,000

'

'

Fair_Value_of_Consideration_Tr

Fair Value of Consideration Transferred (Detail) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Aug. 01, 2012	Aug. 01, 2011
	Esterel Technologies, S.A.	Apache Design Inc [Member]
Business Acquisition [Line Items]	'	'
Payments to Acquire Businesses, Gross	'	$301,306
Contingent consideration	'	9,501
ANSYS replacement stock options	'	3,170
Total consideration transferred at fair value	$58,150	$313,977

Recognized_Amounts_of_Identifi

Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed (Detail) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Aug. 01, 2012

Dec. 31, 2011

Aug. 01, 2012

Aug. 01, 2012

Aug. 01, 2012

Aug. 01, 2011

Aug. 01, 2011

Aug. 01, 2011

Aug. 01, 2011

Aug. 01, 2011

Aug. 01, 2012

Aug. 01, 2011

In Thousands, unless otherwise specified

Esterel Technologies, S.A.

Esterel Technologies, S.A.

Esterel Technologies, S.A.

Apache Design Inc [Member]

Apache Design Inc [Member]

Apache Design Inc [Member]

Apache Design Inc [Member]

Apache Design Inc [Member]

Platform Trade Names

Platform Trade Names

Developed Software

Customer Relationships

Developed Software

Customer Relationships

Contract Backlog

Apache Trade Name

Esterel Technologies, S.A.

Apache Design Inc [Member]

Business Combination, Separately Recognized Transactions [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Contingent Consideration, Liability

'

'

'

'

'

'

'

($9,501)

'

'

'

'

'

'

Cash and short-term investments

'

'

'

'

13,075

'

'

31,948

'

'

'

'

'

'

Accounts receivable and other tangible assets

'

'

'

'

4,737

'

'

6,011

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill

'

'

'

'

'

10,717

21,421

'

82,500

36,100

13,500

2,100

2,695

21,900

Accounts payable and other liabilities

'

'

'

'

-4,707

'

'

-16,867

'

'

'

'

'

'

Deferred revenue

'

'

'

'

-1,139

'

'

-10,100

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent

'

'

10,000

'

-7,096

'

'

-47,229

'

'

'

'

'

'

Total identifiable net assets

'

'

'

'

39,703

'

'

119,863

'

'

'

'

'

'

Goodwill

$1,255,704

$1,251,247

'

$1,225,375

$18,447

'

'

$194,114

'

'

'

'

'

'

Recognized_Amounts_of_Identifi1

Recognized Amounts of Identifiable Assets Acquired and Liabilities Assumed (Parenthetical) (Detail)	1 Months Ended				0 Months Ended
	Aug. 01, 2011	Aug. 01, 2011	Aug. 01, 2011	Aug. 01, 2011	Aug. 01, 2012	Aug. 01, 2012
	Apache Design Inc [Member]	Apache Design Inc [Member]	Apache Design Inc [Member]	Apache Design Inc [Member]	Esterel Technologies, S.A.	Esterel Technologies, S.A.
	Developed Software	Customer Relationships	Contract Backlog	Apache Trade Name	Developed Software	Customer Relationships
Business Combination, Separately Recognized Transactions [Line Items]	'	'	'	'	'	'
Useful life of intangible assets acquired, in years	'7 years	'15 years	'3 years	'6 years	'10 years	'12 years

Other_Current_Assets_Additiona

Other Current Assets - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Supplemental Balance Sheet Information [Line Items]	'	'
Other receivables and current assets	$200,734	$216,268
Accounts Receivable Current Portion Of Annual Lease Licenses And Software Maintenance [Member]	'	'
Supplemental Balance Sheet Information [Line Items]	'	'
Other receivables and current assets	140,100	149,300
Taxes Receivable Related To Overpayments And Refunds	'	'
Supplemental Balance Sheet Information [Line Items]	'	'
Other receivables and current assets	$42,400	$48,900

Other_LongTerm_Liabilities_Det

Other Long-Term Liabilities (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Other Liabilities Disclosure [Abstract]	'	'
Uncertain tax positions	$18.80	$37

Property_and_Equipment_Narrati

Property and Equipment (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Abstract]	'	'	'
Depreciation and amortization expense related to property and equipment	$19.90	$17.40	$13.30

Property_and_Equipment_Compone

Property and Equipment (Components Of Property and Equipment) (Details) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

In Thousands, unless otherwise specified

Equipment

Equipment

Developed Software and Core Technologies

Developed Software and Core Technologies

Buildings

Buildings

Leasehold Improvements

Leasehold Improvements

Furniture

Furniture

Land

Land

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Equipment

Developed Software and Core Technologies

Buildings

Leasehold Improvements

Furniture

Equipment

Developed Software and Core Technologies

Buildings

Leasehold Improvements

Furniture

Property, Plant and Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property and equipment, gross

$136,218

$115,535

$68,970

$59,580

$27,647

$26,864

$24,325

$15,122

$8,125

$7,334

$4,973

$4,457

$2,178

$2,178

'

'

'

'

'

'

'

'

'

'

'

'

Less: Accumulated depreciation and amortization

-75,680

-63,282

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property and equipment, net

$60,538

$52,253

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property and equipment, estimated useful lives (years)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'1 year

'1 year

'1 year

'10 years

'1 year

'1 year

'40 years

'10 years

'5 years

'40 years

'10 years

'10 years

Intangible_Assets_and_Estimate

Intangible Assets and Estimated Useful Lives (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Intangible Assets [Line Items]	'	'
Amortized intangible assets, Gross Carrying Amount	$640,317	$643,152
Amortized intangible assets, Accumulated Amortization	-373,594	-317,126
Unamortized intangible assets, Gross Carrying Amount	24,667	'
Developed Software and Core Technologies	'	'
Intangible Assets [Line Items]	'	'
Amortized intangible assets, Gross Carrying Amount	300,493	298,802
Amortized intangible assets, Accumulated Amortization	-203,236	-175,988
Customer lists and contract backlog	'	'
Intangible Assets [Line Items]	'	'
Amortized intangible assets, Gross Carrying Amount	237,173	241,721
Amortized intangible assets, Accumulated Amortization	-119,368	-100,702
Trade Names [Member]	'	'
Intangible Assets [Line Items]	'	'
Amortized intangible assets, Gross Carrying Amount	102,651	102,629
Amortized intangible assets, Accumulated Amortization	-50,990	-40,436
Trade Names [Member]	'	'
Intangible Assets [Line Items]	'	'
Unamortized intangible assets, Gross Carrying Amount	$24,667	$25,147

Intangible_Assets_and_Estimate1

Intangible Assets and Estimated Useful Lives (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2013
Minimum [Member] | Developed Software and Core Technologies	'
Intangible Assets [Line Items]	'
Useful life of intangible assets acquired, in years	'5 years
Minimum [Member] | Customer lists and contract backlog	'
Intangible Assets [Line Items]	'
Useful life of intangible assets acquired, in years	'3 years
Minimum [Member] | Trade Names [Member]	'
Intangible Assets [Line Items]	'
Useful life of intangible assets acquired, in years	'6 years
Maximum [Member] | Developed Software and Core Technologies	'
Intangible Assets [Line Items]	'
Useful life of intangible assets acquired, in years	'10 years
Maximum [Member] | Customer lists and contract backlog	'
Intangible Assets [Line Items]	'
Useful life of intangible assets acquired, in years	'15 years
Maximum [Member] | Trade Names [Member]	'
Intangible Assets [Line Items]	'
Useful life of intangible assets acquired, in years	'10 years

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'
Amortization	$60.70	$67.30	$51.70

Estimated_Future_Amortization_

Estimated Future Amortization Expense for Intangible Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'	'
2014	$54,119	'
2015	50,482	'
2016	43,374	'
2017	39,604	'
2018	25,982	'
Thereafter	53,162	'
Total intangible assets subject to amortization	266,723	'
Indefinite-lived trade names	24,667	'
Other intangible assets, net	$291,390	$351,173

Changes_in_Goodwill_Detail

Changes in Goodwill (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Roll Forward]	'	'
Beginning balance	$1,251,247	$1,225,375
Acquisitions	5,936	20,866
Currency translation and other	-1,479	5,006
Ending balance	$1,255,704	$1,251,247

Borrowings_Detail

Borrowings (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Less current portion	$0	($53,149)

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]	'	'	'
Aggregate principal payments	$53,149	$74,408	$31,889
Interest rate on term loan	1.04%	1.22%	1.05%

Interest_Expense_on_Term_Loan_

Interest Expense on Term Loan and Amortization Related to Debt Financing Costs (Detail) (July 31, 2008 Term Loan, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
July 31, 2008 Term Loan	'	'	'
Debt Disclosure [Line Items]	'	'	'
Interest Expense	$230	$1,342	$1,605
Amortization	$149	$698	$953

Fair_Value_of_Assets_and_Liabi

Fair Value of Assets and Liabilities Measured on Recurring Basis (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	$303,138	$206,979
Short-term investments	500	452
Contingent consideration	-7,389	-6,436
Foreign currency future	'	-240
Deferred compensation liability	-704	-1,394
Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	303,138	206,979
Short-term investments	0	0
Contingent consideration	0	0
Foreign currency future	'	0
Deferred compensation liability	0	0
Significant Other Observable Inputs (Level 2)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	0	0
Short-term investments	500	452
Contingent consideration	0	0
Foreign currency future	'	-240
Deferred compensation liability	0	0
Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash equivalents	0	0
Short-term investments	0	0
Contingent consideration	-7,389	-6,436
Foreign currency future	'	0
Deferred compensation liability	($704)	($1,394)

Fair_Value_Measurement_Additio

Fair Value Measurement - Additional Information (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Aug. 01, 2011	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified			Apache Design Inc [Member]	Significant Unobservable Inputs (Level 3)	Significant Unobservable Inputs (Level 3)
Fair Value Measurements [Line Items]	'	'	'	'	'
Short-term investment time deposits maturity minimum, in months	'3 months	'	'	'	'
Short-term investment time deposits maturity maximum, in years	'1 year	'	'	'	'
Foreign currency future	'	$240	'	'	$0
Deferred compensation liability	-704	-1,394	'	-704	-1,394
Contingent consideration liability	'	'	($9,501)	'	'

Changes_in_Level_3_Liabilities

Changes in Level 3 Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Detail) (Significant Unobservable Inputs (Level 3), USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Apr. 03, 2013
Contingent Consideration	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Beginning balance	$6,436	$9,571	'
Contingent payments	-3,288	-3,288	'
Business Combination, Contingent Consideration, Liability	'	'	3,597
Interest expense included in earnings	644	153	'
Ending balance	7,389	6,436	'
Deferred Compensation	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Beginning balance	1,394	2,073	'
Contingent payments	-712	-712	'
Business Combination, Contingent Consideration, Liability	0	'	'
Interest expense included in earnings	22	33	'
Ending balance	$704	$1,394	'

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$0.70	'
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	15.8	'
Tax credit carryforwards	4.1	'
Liability for penalties	1.6	2.1
Liability for interest	2.7	2.5
Tax Benefit From Effective Settlement Of 2009 and 2010 Refund Claims	11	'
Not Subject To Expiration [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Tax credit carryforwards	1.8	'
Subject To Expiration [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Tax credit carryforwards	2.3	'
Federal Domestic [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Net operating loss carryforwards	4.6	'
Foreign Country [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Net operating loss carryforwards	70.6	'
Foreign Country [Member] | Subject To Expiration [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Net operating loss carryforwards	51.1	'
Operating Loss Carryforward With No Expiration Date [Member] | Foreign Country [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Net operating loss carryforwards	19.5	'
Subject To Utilization Limitations [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Tax credit carryforwards	1.2	'
Minimum [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Years open to examination	'2008	'
Years under examination	'2008	'
Maximum [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Years open to examination	'2013	'
Years under examination	'2011	'
Foreign Subsidiary Earnings Repatriation [Member]	'	'
Income Tax Contingency [Line Items]	'	'
Amount in excess of the amount for financial reporting over the tax bases	173.1	'
Deferred Tax Liabilities, Undistributed Foreign Earnings	46.1	'
Income Tax Expense (Benefit), Repatriation of Foreign Earnings, Expected in Next Twelve Months	0.1	'
Expected foreign subsidiary earnings repatriation	$15.80	'

Income_Taxes_Components_Of_Inc

Income Taxes (Components Of Income Before Income Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Domestic	$272,569	$234,497	$205,966
Foreign	49,920	59,050	58,892
Income before income tax provision	$322,489	$293,547	$264,858

Income_Taxes_Components_Of_Pro

Income Taxes (Components Of Provision For Income Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Current, Federal	$69,268	$79,028	$57,423
Current, State	7,197	7,886	5,770
Current, Foreign	24,722	22,046	24,011
Deferred, Federal	-23,438	-21,026	-11,768
Deferred, State	-2,187	-3,913	-1,314
Deferred, Foreign	1,600	6,043	10,061
Total	$77,162	$90,064	$84,183

Income_Taxes_Reconciliation_Of

Income Taxes (Reconciliation Of U.S. Federal Statutory Tax Rate To Consolidated Effective Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Federal statutory tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	1.10%	1.20%	1.10%
Stock-based compensation	0.90%	1.00%	1.00%
Changes in tax rates	0.30%	0.80%	2.20%
Net tax (benefit) of unrepatriated earnings	-0.90%	0.70%	0.00%
Uncertain tax positions	-3.70%	0.30%	0.20%
Benefit from restructuring activities	-2.80%	-3.10%	-3.50%
Domestic production activity benefit	-3.30%	-3.30%	-2.90%
Foreign rate differential	-0.90%	-1.90%	-1.10%
Research and experimentation credits	-2.00%	-0.10%	-0.90%
Adjustments of prior year taxes	-0.10%	-1.30%	-0.30%
Other	0.30%	1.40%	1.00%
Consolidated effective tax rate	23.90%	30.70%	31.80%

Income_Taxes_Components_Of_Def

Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Net operating loss carryforwards	$26,204	$26,228
Employee benefits	18,824	17,670
Stock-based compensation	20,006	16,092
Foreign tax credits	403	558
Other accruals not currently deductible	1,165	1,207
Research and development credits	2,331	2,254
Uncertain tax positions	7,977	7,790
Deferred revenue	7,816	5,139
Allowance for doubtful accounts	2,014	1,661
Other	1,953	2,227
Valuation allowance	-392	-14
Deferred tax assets	88,301	80,812
Other intangible assets	-106,115	-128,671
Property and equipment	-4,556	-5,838
Unremitted foreign earnings	-115	-2,204
Deferred tax liabilities	-110,786	-136,713
Net deferred tax liability	($22,485)	($55,901)

Income_Taxes_Reconciliation_Of1

Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]	'	'	'
Unrecognized tax benefit as of January 1	$37,203	$31,582	$19,993
Acquired unrecognized tax benefit	0	3,845	5,813
Gross increases-tax positions in prior period	320	2,048	6,814
Gross decreases-tax positions in prior period	-18,058	-2,167	-2,697
Gross increases-tax positions in current period	2,036	2,660	2,297
Reductions due to a lapse of the applicable statute of limitations	-1,734	-1,314	-190
Changes due to currency fluctuation	20	625	-448
Settlements	-197	-76	0
Unrecognized tax benefit as of December 31	$19,590	$37,203	$31,582

Pension_And_ProfitSharing_Plan1

Pension And Profit-Sharing Plans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
401(k)/Profit-Sharing Plan	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Matching contributions by employer, description	'The Company makes matching contributions on behalf of each eligible participant in an amount equal to 100% of the first 3% and an additional 25% of the next 5%, for a maximum total of 4.25% of the employee’s compensation.	'	'
Percentage of employee pay employer matches	4.25%	'	'
Minimum working hours per employee required to be eligible for discretionary contribution	'1000 hours	'	'
Expenses related to retirement programs	$8	$7.10	$5.30
First 3% Of Employee Pay	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Percentage of employee pay employer matches	3.00%	'	'
Percentage of employee contribution employer matches	100.00%	'	'
More Than 3% up to 5% Of Employee Pay [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Percentage of employee pay employer matches	5.00%	'	'
Percentage of employee contribution employer matches	25.00%	'	'

Recovered_Sheet1

Non-Compete And Employment Agreements (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Board Of Directors Chairman [Member]	'
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'
Expected severance costs in the event of termination of chairman	$300,000
Maximum [Member]	'
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'
Severance pay period	'1 year

Stock_Option_And_Grant_Plan_Na

Stock Option And Grant Plan (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Shares authorized for grant under the plan	30,400,000	'	'
Percentage of voting interest to be held by optionee	10.00%	'	'
Exercise price as a percentage of fair value at the time of grant	110.00%	'	'
Expiration period of options from the date of grant	'10 years	'	'
Expiration period for optionee who meets the 10% criteria	'5 years	'	'
Vesting period	'4 years	'	'
Maximum months after sale event where awards fully vest when service relationship terminated without cause	'18 months	'	'
Maximum number of days that may be granted to terminated employee to exercise awards prior to termination	'15 days	'	'
Total estimated grant date fair values of stock options vested during period	$24,700,000	$23,300,000	$20,200,000
Total unrecognized estimated compensation cost	39,900,000	'	'
Weighted average period of recognition of unrecognized compensation cost (years)	'1 year 8 months 12 days	'	'
Total intrinsic value of options exercised during the period	45,200,000	64,700,000	42,600,000
Unvested options	1,800,000	'	'
Aggregate intrinsic value of unvested options	48,300,000	'	'
Weighted average exercise price of unvested options	$60.59	'	'
Weighted average remaining contractual term of unvested stock options (years)	'8 years	'	'
Cash received from the exercise of stock options	34,007,000	31,960,000	22,791,000
Tax benefit from exercise of stock options	21,100,000	'	'
Excess tax benefit from exercise of stock options	9,971,000	13,888,000	10,046,000
Deferred Stock Units [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Deferred stock units earned with underlying shares remaining unissued until the service termination	115,842	'	'
Deferred stock units earned during the period	26,215	'	'
Performance Based Restricted Stock Units [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Number of performance-based restricted stock units granted	94,300	100,000	92,500
Value of the restricted stock units on the grant date	$50.05	$33.16	$32.05
Number of shares available for offerings under purchase plan	92,500	'	'
Stock-based compensation expense	3,600,000	2,600,000	1,600,000
Compensation expense expected to be recorded in 2014	2,800,000	'	'
Compensation expense expected to be recorded in 2015	1,700,000	'	'
Apache Performance Restricted Stock Units	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Value of the restricted stock units on the grant date	$50.30	'	'
Stock-based compensation expense	3,800,000	3,900,000	'
Business acquisition, potential performance equity awards	$13,000,000	'	'
Restricted Stock Units Earned	75,477	'	'

Stock_Option_And_Grant_Plan_Su

Stock Option And Grant Plan (Summary Of Stock Options) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'	'	'
Outstanding, beginning of year, Options	7,122	7,545	7,319
Granted, Options	103	1,109	1,104
Issued pursuant to apache Acquisition, Options	0	0	418
Exercised, Options	-993	-1,464	-1,179
Forfeited, Options	-66	-68	-117
Outstanding, end of year, Options	6,166	7,122	7,545
Vested and Exercisable, end of year, Options	4,351	4,094	4,251
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]	'	'	'
Outstanding, beginning of period, Weighted Average Exercise Price	$42.85	$35.10	$29.92
Granted, Weighted Average Exercise Price	$81.87	$67.53	$58.50
Issued pursuant to Apache acquisition	$0	$0	$18.66
Exercised, Weighted Average Exercise Price	$34.26	$21.85	$19.33
Forfeited, Weighted Average Exercise Price	$53.75	$36.90	$33.27
Outstanding, end of period, Weighted Average Exercise Price	$44.77	$42.85	$35.10
Vested and Exercisable, end of period, Weighted Average Exercise Price	$38.18	$33.91	$27.98
Outstanding, Weighted Average Remaining Contractual Term (in years)	'5 years 11 months 26 days	'6 years 9 months 11 days	'6 years 7 months 28 days
Vested and Exercisable, Weighted Average Remaining Contractual Term (in years)	'5 years 1 month 17 days	'5 years 5 months 23 days	'5 years 2 months 12 days
Outstanding, Aggregate Intrinsic Value	$261,601	$174,383	$168,837
Vested and Exercisable, Aggregate Intrinsic Value	$213,304	$136,851	$124,550

Stock_Option_And_Grant_Plan_St

Stock Option And Grant Plan (Stock-Based Compensation Expense) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Stock-based compensation expense before taxes	$35,298	$32,415	$23,088
Related income tax benefits	-11,096	-8,509	-5,552
Stock-based compensation expense, net of taxes	24,202	23,906	17,536
Basic earnings per share	($0.26)	($0.26)	($0.19)
Diluted earnings per share	($0.25)	($0.25)	($0.19)
Software Licenses	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Stock-based compensation expense before taxes	1,349	1,478	556
Maintenance And Service [Member]	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Stock-based compensation expense before taxes	2,293	2,232	1,897
Selling, General And Administrative [Member]	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Stock-based compensation expense before taxes	16,847	15,278	12,501
Research And Development [Member]	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Stock-based compensation expense before taxes	$14,809	$13,427	$8,134

Stock_Option_And_Grant_Plan_As

Stock Option And Grant Plan (Assumptions To Estimate Fair Value Of Stock Awards) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Risk-free interest rate, minimum	0.68%	0.59%	0.91%
Risk-free interest rate, maximum	1.48%	1.04%	2.11%
Expected dividend yield	0.00%	0.00%	0.00%
Expected volatility	37.00%	38.00%	39.00%
Expected term (in years)	'5 years 9 months 6 days	'6 years	'5 years 9 months 18 days
Weighted average fair value per share	$29.85	$24.82	$25.84
Restricted Stock Unit Compensation Expense [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Risk-free interest rate	0.35%	0.16%	1.35%
Expected dividend yield	0.00%	0.00%	0.00%
Expected term (in years)	'2 years 9 months 18 days	'2 years 9 months 18 days	'2 years 10 months 24 days
Correlation factor	0.7	0.75	0.7
Restricted Stock Unit Compensation Expense [Member] | ANSYS Stock Price [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected volatility	25.00%	28.00%	40.00%
Restricted Stock Unit Compensation Expense [Member] | NASDAQ Composite Index [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected volatility	20.00%	20.00%	25.00%

Stock_Option_And_Grant_Plan_In

Stock Option And Grant Plan (Information Regarding Stock Options Outstanding) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013
$5.91 - $28.40	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Limit	$5.91
Range of Exercise Prices, Upper Limit	$28.40
Options Outstanding, Options	1,747
Options Outstanding, Weighted Average Remaining Contractual Life (years)	'3 years 7 months 20 days
Options Outstanding, Weighted Average Exercise Price	$22.40
Options Exercisable, Options	1,662
Options Exercisable, Weighted Average Exercise Price	$22.44
$29.97 - $40.89	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Limit	$29.97
Range of Exercise Prices, Upper Limit	$40.89
Options Outstanding, Options	1,272
Options Outstanding, Weighted Average Remaining Contractual Life (years)	'4 years 9 months 14 days
Options Outstanding, Weighted Average Exercise Price	$39.54
Options Exercisable, Options	1,269
Options Exercisable, Weighted Average Exercise Price	$39.53
$41.33 - $58.67	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Limit	$41.33
Range of Exercise Prices, Upper Limit	$58.67
Options Outstanding, Options	1,983
Options Outstanding, Weighted Average Remaining Contractual Life (years)	'7 years 2 months 12 days
Options Outstanding, Weighted Average Exercise Price	$53.73
Options Exercisable, Options	1,170
Options Exercisable, Weighted Average Exercise Price	$52.77
$60.49 - $88.35	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'
Range of Exercise Prices, Lower Limit	$60.49
Range of Exercise Prices, Upper Limit	$88.35
Options Outstanding, Options	1,164
Options Outstanding, Weighted Average Remaining Contractual Life (years)	'8 years 7 months 20 days
Options Outstanding, Weighted Average Exercise Price	$68.80
Options Exercisable, Options	250
Options Exercisable, Weighted Average Exercise Price	$67.55

Stock_Repurchase_Program_Addit

Stock Repurchase Program - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, except Share data in Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure Stock Repurchase Program Additional Information [Abstract]	'	'	'
Number of shares repurchased under stock repurchase program	1.5	1.5	'
Average repurchase price per share	$77.73	$63.65	'
Payments for Repurchase of Common Stock	$116,132	$95,477	$12,704
Remaining number of shares authorized to be repurchased under stock repurchase program	1.5	'	'

Employee_Stock_Purchase_Plan_E

Employee Stock Purchase Plan Employee Stock Purchase Plan (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]	'	'	'
Number of shares available for offerings	30,400,000	'	'
Employee Stock | ANSYS 1996 Employee Stock Purchase Plan [Member]	'	'	'
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]	'	'	'
Number of shares available for offerings	1,600,000	'	'
Maximum number of shares per employee	3,840	'	'
Shares of common stock issued under Purchase Plan	1,282,578	1,233,385	'
Stock-based compensation expense	$765	$706	$650
Maximum [Member] | Employee Stock | ANSYS 1996 Employee Stock Purchase Plan [Member]	'	'	'
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]	'	'	'
Eligibility, ownership percentage of voting power of all classes of stock of the company	5.00%	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	10.00%	'	'
Purchase price of common stock, percent	90.00%	'	'
Maximum employee subscription rate, value	$25	'	'

Leases_Details

Leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	sqft
Operating Leased Assets [Line Items]	'	'	'
Construction In Progress Leased Facility	$18,136,000	$0	'
Canonsburg Office | Amended Lease Agreement Effective January 1, 2004	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Area of Real Estate Property	107,000	'	'
Lease rental expense incurred	1,300,000	1,300,000	1,300,000
Operating Leases, Future Minimum Payments Due, Next Twelve Months	1,400,000	'	'
Canonsburg Office, New Company Headquarters | Lease Agreement Effective September 14, 2012	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Area of Real Estate Property	186,000	'	'
Period of leased property (years)	'183 months	'	'
Base rent, years one through five	4,300,000	'	'
Base rent, years six through ten	4,500,000	'	'
Base rent, years eleven through fifteen	4,700,000	'	'
Pittsburgh Office	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Future minimum lease payments, Year Two	570,000	'	'
Global Office Space	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Lease rental expense incurred	14,100,000	13,700,000	12,800,000
Operating Leases, Future Minimum Payments Due, Next Twelve Months	11,700,000	'	'
Future minimum lease payments, Year Two	10,800,000	'	'
Future minimum lease payments, Year 3	8,700,000	'	'
Future minimum lease payments, Year 4	7,200,000	'	'
Future minimum lease payments, Year 5	6,600,000	'	'
Apache Design Inc [Member] | San Jose Office [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Area of Real Estate Property	52,000	'	'
Future minimum lease payments	8,400,000	'	'
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$900,000	'	'

Royalty_Agreements_Details

Royalty Agreements (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Royalty Agreements [Abstract]	'	'	'
Royalty fees reported in cost of goods sold	$10.30	$9.30	$8.40

Revenue_by_Geographic_Area_Det

Revenue by Geographic Area (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Total revenue	$861,260	$798,018	$691,449
UNITED STATES	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Total revenue	292,323	265,436	215,924
Japan	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Total revenue	108,064	122,437	112,171
Germany	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Total revenue	93,525	82,008	72,301
Canada	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Total revenue	14,163	12,384	12,069
Other European	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Total revenue	201,614	177,069	166,551
Other International	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'
Total revenue	$151,571	$138,684	$112,433

Property_and_Equipment_by_Geog

Property and Equipment by Geographic Area (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	$60,538	$52,253
UNITED STATES	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	45,116	36,716
United Kingdom	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	3,016	3,532
India	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	3,226	3,392
France	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	2,275	2,378
Germany	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	2,328	2,087
Japan	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	1,383	1,253
Canada	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	618	753
Other European	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	1,476	1,173
Other International	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'
Total property and equipment	$1,100	$969

Unconditional_Purchase_Obligat1

Unconditional Purchase Obligations (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Unconditional Purchase Obligations (Excluding Capital Stock Redemptions) [Abstract]	'	'	'
Unconditional purchase obligations, beginning of year	$3,300,000	$4,000,000	$5,000,000
Future expenditures under purchase obligations, Next Twelve Months	2,900,000	'	'
Future expenditures under purchase obligations, Year Two	800,000	'	'
Future expenditures under purchase obligations, Year Three	$200,000	'	'

Contingencies_and_Commitments_1

Contingencies and Commitments - Additional Information (Detail) (Maximum [Member], USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Maximum [Member]	'
Other Commitments And Contingencies [Line Items]	'
Tax charges and related liabilities if the ruling is unfavorable	$6

Schedule_II_Valuation_and_Qual1

Schedule II - Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Valuation and Qualifying Accounts Disclosure [Line Items]	'	'	'
Provisions for doubtful accounts	$1,465	$938	$404
Allowance for Doubtful Accounts	'	'	'
Valuation and Qualifying Accounts Disclosure [Line Items]	'	'	'
Provisions for doubtful accounts	1,465	938	404
Movement in Valuation Allowances and Reserves [Roll Forward]	'	'	'
Balance at Beginning of Year	4,800	4,101	4,503
Deductions - Returns and Write-Offs	565	239	806
Balance at End of Year	$5,700	$4,800	$4,101