Citrix Systems (CTXS) 10-Q 1 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 25, 2019
Cover page.
Title of 12(b) Security	Common Stock, par value $.001 per share
Entity Incorporation, State or Country Code	DE
Document Transition Report	false
Document Quarterly Report	true
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Entity File Number	0-27084
City Area Code	954
Local Phone Number	267-3000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	CTXS
Entity Registrant Name	CITRIX SYSTEMS, INC.
Entity Central Index Key	0000877890
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		130,219,842
Entity Tax Identification Number	75-2275152
Entity Address, Address Line One	851 West Cypress Creek Road
Entity Address, City or Town	Fort Lauderdale
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33309
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Current assets:
Cash and cash equivalents	$ 493,834	$ 618,766	$ 1,205,182
Short-term investments, available-for-sale	55,372	583,615
Accounts receivable, net of allowances of $6,962 and $4,530 at September 30, 2019 and December 31, 2018, respectively	426,842	688,420
Inventories, net	18,518	21,905
Prepaid expenses and other current assets	199,434	174,195
Total current assets	1,194,000	2,086,901
Long-term investments, available-for-sale	21,374	574,319
Property and equipment, net	236,788	243,396
Operating lease right-of-use assets	218,625	0
Goodwill	1,798,408	1,802,670
Other intangible assets, net	119,055	167,187
Deferred tax assets, net	301,062	136,998
Other assets	141,781	124,578
Total assets	4,031,093	5,136,049
Current liabilities:
Accounts payable	72,659	75,551
Accrued expenses and other current liabilities	294,915	290,492
Income taxes payable	45,615	44,409
Current portion of convertible notes	0	1,155,445
Current portion of deferred revenues	1,200,496	1,345,243
Total current liabilities	1,613,685	2,911,140
Long-term portion of deferred revenues	415,076	489,329
Long-term debt	742,704	741,825
Long-term income taxes payable	259,391	285,627
Operating lease liabilities	221,032	0
Other liabilities	66,294	148,499
Commitments and contingencies
Temporary equity from convertible notes	0	8,110
Stockholders' equity:
Preferred stock at $.01 par value: 5,000 shares authorized, none issued and outstanding	0	0
Common stock at $.001 par value: 1,000,000 shares authorized; 317,549 and 309,761 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively	318	310
Additional paid-in capital	6,170,577	5,404,500
Retained earnings	4,500,876	4,169,019
Accumulated other comprehensive loss	(6,482)	(8,154)
Stockholders' equity before treasury stock	10,665,289	9,565,675
Less - common stock in treasury, at cost (187,661 and 178,327 shares at September 30, 2019 and December 31, 2018, respectively)	(9,952,378)	(9,014,156)
Total stockholders' equity	712,911	551,519
Total liabilities, temporary equity and stockholders' equity	$ 4,031,093	$ 5,136,049

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 6,962	$ 4,530
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	317,549,000	309,761,000
Common stock, shares outstanding	317,549,000	309,761,000
Common stock in treasury, shares	187,661,000	178,327,000

Condensed Consolidated Statemen

Condensed Consolidated Statements Of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Revenue	$ 732,901	$ 732,476	$ 2,200,741	$ 2,172,033
Cost of net revenues:
Total cost of net revenues	126,918	103,917	344,870	320,952
Gross margin	605,983	628,559	1,855,871	1,851,081
Operating expenses:
Research and development	126,420	111,557	390,712	323,050
Sales, marketing and services	274,874	262,562	847,958	800,505
General and administrative	80,042	86,084	238,751	227,151
Amortization of other intangible assets	4,937	4,063	11,671	11,748
Restructuring	8,879	(486)	16,022	13,138
Total operating expenses	495,152	463,780	1,505,114	1,375,592
Income from operations	110,831	164,779	350,757	475,489
Interest income	2,649	10,896	16,193	29,029
Interest expense	(8,822)	(19,962)	(37,144)	(60,840)
Other income (expense), net	3,456	3,702	3,735	(1,847)
Income before income taxes	108,114	159,415	333,541	441,831
Income tax (benefit) expense	(162,743)	558	(141,159)	31,882
Net income	$ 270,857	$ 158,857	$ 474,700	$ 409,949
Earnings per share:
Basic earnings per share (in dollars per share)	$ 2.08	$ 1.18	$ 3.62	$ 3
Diluted earnings per share (in dollars per share)	$ 2.04	$ 1.08	$ 3.48	$ 2.80
Weighted average shares outstanding:
Basic (in shares)	130,277	135,055	131,020	136,752
Diluted (in shares)	132,655	147,568	136,297	146,554
Subscription [Member]
Revenues:
Revenue	$ 159,873	$ 111,539	$ 457,312	$ 325,493
Product and License [Member]
Revenues:
Revenue	131,057	170,952	406,733	523,707
Cost of net revenues:
Cost of net revenues	27,411	27,571	75,033	91,150
Support and Services [Member]
Revenues:
Revenue	441,971	449,985	1,336,696	1,322,833
Subscription, Support and Service [Member]
Cost of net revenues:
Cost of net revenues	76,885	64,717	227,130	195,625
Product [Member]
Cost of net revenues:
Amortization and impairment of product related intangible assets	$ 22,622	$ 11,629	$ 42,707	$ 34,177

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unuaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 270,857	$ 158,857	$ 474,700	$ 409,949
Available for sale securities:
Change in net unrealized gains (losses)	57	816	2,859	(3,394)
Less: reclassification adjustment for net losses (gains) included in net income	7	62	(577)	1,307
Net change (net of tax effect)	64	878	2,282	(2,087)
Cash flow hedges:
Change in unrealized losses	(1,774)	(1,636)	(1,439)	(4,367)
Less: reclassification adjustment for net (gains) losses included in net income	(162)	1,185	829	(1,031)
Net change (net of tax effect)	(1,936)	(451)	(610)	(5,398)
Other comprehensive (loss) income	(1,872)	427	1,672	(7,485)
Comprehensive income	$ 268,985	$ 159,284	$ 476,372	$ 402,464

Condensed Consolidated Statem_3

Condensed Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating Activities
Net income	$ 474,700	$ 409,949
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	188,443	161,582
Stock-based compensation expense	202,523	144,306
Deferred income tax (benefit) expense	(184,573)	2,508
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies	2,712	7,226
Other non-cash items	7,888	5,558
Total adjustments to reconcile net income to net cash provided by operating activities	216,993	321,180
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable	256,628	296,286
Inventories	443	(7,549)
Prepaid expenses and other current assets	(13,539)	(51,726)
Other assets	(50,068)	(17,540)
Income taxes, net	(42,119)	(83,273)
Accounts payable	(2,645)	2,945
Accrued expenses and other current liabilities	(48,485)	40,503
Deferred revenues	(219,000)	(85,072)
Other liabilities	4,111	3,233
Total changes in operating assets and liabilities, net of the effects of acquisitions	(114,674)	97,807
Net cash provided by operating activities	577,019	828,936
Investing Activities
Purchases of available-for-sale investments	(19,999)	(435,876)
Proceeds from sales of available-for-sale investments	938,031	442,360
Proceeds from maturities of available-for-sale investments	165,944	320,259
Purchases of property and equipment	(50,453)	(54,289)
Cash paid for acquisitions, net of cash acquired	0	(65,983)
Cash paid for licensing agreements, patents and technology	(2,405)	(2,140)
Other	919	1,399
Net cash provided by investing activities	1,032,037	205,730
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plans	0	164
Proceeds from credit facility	200,000	0
Repayment of credit facility	(200,000)	0
Repayment of acquired debt	0	(5,674)
Repayment on convertible notes	(1,164,497)	0
Stock repurchases, net	(353,904)	(881,153)
Cash paid for tax withholding on vested stock awards	(74,794)	(53,589)
Cash paid for dividends	(137,224)	0
Net cash used in financing activities	(1,730,419)	(940,252)
Effect of exchange rate changes on cash and cash equivalents	(3,569)	(4,362)
Change in cash and cash equivalents	(124,932)	90,052
Cash and cash equivalents at beginning of period	$ 618,766	$ 1,115,130

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements of Citrix Systems, Inc. (the "Company") have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States for complete financial statements. All adjustments, which, in the opinion of management, are considered necessary for a fair presentation of the results of operations for the periods shown, are of a normal recurring nature and have been reflected in the condensed consolidated financial statements and accompanying notes. The results of operations for the periods presented are not necessarily indicative of the results expected for the full year or for any future period partially because of the seasonality of the Company’s business. Historically, the Company’s revenue for the fourth quarter of any year is typically higher than the revenue for the first quarter of the subsequent year. The information included in these condensed consolidated financial statements should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in this report and the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 . The condensed consolidated financial statements of the Company include the accounts of its wholly-owned subsidiaries in the Americas; Europe, the Middle East and Africa (“EMEA”); and Asia-Pacific and Japan (“APJ”). All significant transactions and balances between the Company and its subsidiaries have been eliminated in consolidation. The Company's revenues are derived from sales of its Digital Workspace solutions, Networking products and related Support and services. The Company operates under one

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	SIGNIFICANT ACCOUNTING POLICIES During the first quarter of 2019, the Company adopted new accounting guidance related to leases, which is described below. There have been no other significant changes in the Company’s accounting policies during the three and nine months ended September 30, 2019 as compared to the significant accounting policies described in its Annual Report on Form 10-K for the year ended December 31, 2018 Recent Accounting Pronouncements Leases In February 2016, the Financial Accounting Standards Board issued an accounting standard update on the accounting for leases (“ASC 842”). The new guidance requires that lessees in a leasing arrangement recognize a right-of-use (“ROU”) asset and a lease liability for most leases (other than leases that meet the definition of a short-term lease). The Company adopted this standard as of January 1, 2019 using a modified retrospective approach and recognized a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. In addition, the Company elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed the Company to carry forward the historical lease classification and not reassess whether any expired or existing contract is a lease or contains a lease. Adoption of this standard had a material impact in the Company’s condensed consolidated balance sheets, but did not have a material impact on its condensed consolidated income statements. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while the Company's accounting for finance leases remained substantially unchanged. Adoption of the new standard resulted in the recording of additional right-of-use assets for operating leases (net of previously recorded lease losses related to the consolidation of leased facilities of $42.2 million and deferred rent liability of $20.5 million under the old guidance) of approximately $194.5 million and operating lease liabilities of approximately $256.4 million , as of January 1, 2019. The difference between the additional lease assets and lease liabilities, net of the deferred tax impact, was recorded as an adjustment to retained earnings of $0.8 million . Adoption of this standard had no impact to cash from or used in operating, financing, or investing in the Company’s condensed consolidated cash flows statements. Adoption of this standard had no impact on the Company's debt covenant compliance under its current agreement or on liquidity. See Note 19 for additional information regarding the Company’s leases. Current Expected Credit Losses In June 2016, the Financial Accounting Standards Board issued an accounting standard update on the measurement of credit losses on financial instruments. Previously, credit losses were measured using an incurred loss approach when it was probable that a credit loss had been incurred. The new guidance changes the credit loss model from an incurred loss to an expected loss approach. It requires the application of a current expected credit loss (“CECL”) impairment model to financial assets measured at amortized cost (including trade accounts receivable) and certain off-balance-sheet credit exposures. Under the CECL model, lifetime expected credit losses on such financial assets are measured and recognized at each reporting date based on historical, current, and forecasted information. The standard also changes the impairment model for available-for-sale debt securities, eliminating the concept of other than temporary impairment and requiring credit losses to be recorded through an allowance for credit losses. The amount of the allowance for credit losses for available-for-sale debt securities is limited to the amount by which fair value is below amortized cost. The standard is effective for interim and annual periods beginning after December 15, 2019. Early adoption is permitted. A modified retrospective adoption method is required, with a cumulative-effect adjustment to the opening retained earnings balance in the period of adoption. The adoption of this standard is not expected to have a material impact on the Company's condensed consolidated financial position, results of operations and cash flows. Additionally, the Company is not planning to early adopt this standard. Premium Amortization on Call Debt Securities In March 2017, the Financial Accounting Standards Board issued an accounting standard update on the accounting for amortization of premium costs on purchased callable debt securities. The new guidance amends the amortization period for certain purchased callable debt securities held at a premium, shortening such period to the earliest call date. The standard does not require any accounting change for debt securities held at a discount; the discount continues to be amortized to maturity. The Company adopted the standard effective January 1, 2019 on a modified retrospective basis. The adoption of this standard did not have a material impact on the Company's condensed consolidated financial position, results of operations and cash flows. Accounting for Cloud Computing Costs In August 2018, the Financial Accounting Standards Board issued an accounting standard update on the accounting for implementation costs incurred by customers in cloud computing arrangements that are service contracts. The new guidance aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The Company early adopted this standard on a prospective basis effective January 1, 2019. Adoption of this standard did not have a material impact on the Company's condensed consolidated financial position, results of operations and cash flows. Fair Value Measurements 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 amounts reported in the condensed consolidated financial statements and accompanying notes. Significant estimates made by management include the standalone selling price related to revenue recognition, the provision for doubtful accounts receivable, the provision to reduce obsolete or excess inventory to market, the provision for estimated returns, as well as sales allowances, the assumptions used in the valuation of stock-based awards, the assumptions used in the discounted cash flows to mark certain of its investments to market, the valuation of the Company’s goodwill, net realizable value of product related and other intangible assets, the provision for income taxes, valuation allowance for deferred tax assets, uncertain tax positions, and the amortization and depreciation periods for contract acquisition costs, intangible and long-lived assets. While the Company believes that such estimates are fair when considered in conjunction with the condensed consolidated financial position and results of operations taken as a whole, the actual amounts of such items, when known, will vary from these estimates. Available-for-sale Investments Short-term and long-term available-for-sale investments in debt securities as of September 30, 2019 and December 31, 2018 primarily consist of agency securities, corporate securities, municipal securities and government securities. Investments classified as available-for-sale debt securities are stated at fair value with unrealized gains and losses, net of taxes, reported in Accumulated other comprehensive loss. The Company classifies its available-for-sale investments as current and non-current based on their actual remaining time to maturity. The Company does not recognize changes in the fair value of its available-for-sale investments in income unless a decline in value is considered other-than-temporary in accordance with the authoritative guidance. The Company’s investment policy is designed to limit exposure to any one issuer depending on credit quality. The Company uses information provided by third parties to adjust the carrying value of certain of its investments to fair value at the end of each period. Fair values are based on a variety of inputs and may include interest rates, known historical trades, yield curve information, benchmark data, prepayment speeds, credit quality and broker/dealer quotes. See Note 6 for additional information regarding the Company’s investments. Foreign Currency The functional currency for all of the Company’s wholly-owned foreign subsidiaries is the U.S. dollar. Monetary assets and liabilities of such subsidiaries are remeasured into U.S. dollars at exchange rates in effect at the balance sheet date, and revenues and expenses are remeasured at average rates prevailing during the year. Accounting for Stock-Based Compensation Plans The Company has various stock-based compensation plans for its employees and outside directors and accounts for stock-based compensation arrangements in accordance with the authoritative guidance, which requires the Company to measure and record compensation expense in its condensed consolidated financial statements using a fair value method. See Note 8 for further information regarding the Company’s stock-based compensation plans.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE The following is a description of the principal activities from which the Company generates revenue. Subscription Subscription revenues primarily consist of cloud-hosted offerings which provide customers a right to use, or a right to access, one or more of the Company’s cloud-hosted subscription offerings, with routine customer support, as well as revenues from the Citrix Service Provider ("CSP") program and on-premise subscription software licenses. For the Company’s cloud-hosted performance obligations, revenue is generally recognized on a ratable basis over the contract term beginning on the date that the Company's service is made available to the customer, as the Company continuously provides online access to the web-based software that the customer can use at any time. The CSP program provides subscription-based services in which the CSP partners host software services to their end users. Product and license Product and license revenues are primarily derived from perpetual offerings related to the Company’s Digital Workspace solutions and Networking products. For performance obligations related to perpetual software license agreements, the Company determined that its licenses are functional intellectual property that are distinct as the user can benefit from the software on its own. Support and services Support and services includes license updates, maintenance and professional services revenues. License updates and maintenance revenues are primarily comprised of software and hardware maintenance, when and if-available updates and technical support. For performance obligations related to license updates and maintenance, revenue is generally recognized on a straight-line basis over the period of service because the Company transfers control evenly by providing a stand-ready service. That is, the Company is continuously working on improving its products and pushing those updates through to the customer, and stands ready to provide software updates on a when and if-available basis. Services revenues are comprised of fees from consulting services primarily related to the implementation of the Company’s products and fees from product training and certification. The Company’s typical performance obligations include the following: Performance Obligation When Performance Obligation is Typically Satisfied Subscription Cloud hosted offerings Over the contract term, beginning on the date that service is made available to the customer (over time) CSP As the usage occurs (over time) On-premise subscription software licenses When software activation keys have been made available for download (point in time) Product and license Software Licenses When software activation keys have been made available for download (point in time) Hardware When control of the product passes to the customer; typically upon shipment (point in time) Support and services License updates and maintenance Ratably over the course of the service term (over time) Professional services As the services are provided (over time) Significant Judgments At contract inception, the Company assesses the solutions or services, or bundles of solutions and services, obligated in the contract with a customer to identify each performance obligation within the contract, and then evaluates whether the performance obligations are capable of being distinct and distinct within the context of the contract. Solutions and services that are not both capable of being distinct and distinct within the context of the contract are combined and treated as a single performance obligation in determining the allocation and recognition of revenue. The standalone selling price is the price at which the Company would sell a promised product or service separately to the customer. For the majority of the Company's software licenses and hardware, CSP and on-premise subscription software licenses, the Company uses the observable price in transactions with multiple performance obligations. For the majority of the Company’s support and services, and cloud-hosted subscription offerings, the Company uses the observable price when the Company sells that support and service and cloud-hosted subscription separately to similar customers. If the standalone selling price for a performance obligation is not directly observable, the Company estimates it. The Company estimates standalone selling price by taking into consideration market conditions, economics of the offering and customers’ behavior. The Company maximizes the use of observable inputs and applies estimation methods consistently in similar circumstances. The Company allocates the transaction price to each distinct performance obligation on a relative standalone selling price basis. Revenues are recognized when control of the promised products or services are transferred to customers, in an amount that reflects the consideration that the Company expects to receive in exchange for those products or services. The Company generates all of its revenues from contracts with customers. Sales tax The Company records revenue net of sales tax. Timing of revenue recognition Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In thousands) Products and services transferred at a point in time $ 159,326 $ 186,039 $ 500,450 $ 583,888 Products and services transferred over time 573,575 546,437 1,700,291 1,588,145 Total net revenues $ 732,901 $ 732,476 $ 2,200,741 $ 2,172,033 Contract balances The Company's short-term and long-term contract assets were $4.6 million and $3.7 million , respectively, as of December 31, 2018 , and $9.1 million and $17.6 million , respectively, as of September 30, 2019 . The Current portion of deferred revenues and the Long-term portion of deferred revenues were $1.35 billion and $489.3 million , respectively, as of December 31, 2018 and $1.20 billion and $415.1 million , respectively, as of September 30, 2019 . The difference in the opening and closing balances of the Company’s contract assets and liabilities primarily results from the timing difference between the Company’s performance and the customer’s payment. During the three and nine months ended September 30, 2019 , the Company recognized $478.7 million and $1.13 billion , respectively, of revenue that was included in the deferred revenue balance as of June 30, 2019 and December 31, 2018 , respectively. The Company performs its obligations under a contract with a customer by transferring solutions and services in exchange for consideration from the customer. Accounts receivable are recorded when the right to consideration becomes unconditional. The timing of the Company’s performance often differs from the timing of the customer’s payment, which results in the recognition of a contract asset or a contract liability. The Company recognizes a contract asset when the Company transfers products or services to a customer and the right to consideration is conditional on something other than the passage of time. The Company recognizes a contract liability when it has received consideration or an amount of consideration is due from the customer and the Company has a future obligation to transfer products or services. The Company had no asset impairment charges related to contract assets for the three and nine months ended September 30, 2019 and 2018 . For the Company’s software and hardware products, the timing of payment is typically upfront for its perpetual offerings and the Company’s on-premise subscriptions. Therefore, deferred revenue is created when a contract includes performance obligations such as license updates and maintenance or certain professional services that are satisfied over time. For subscription contracts, the timing of payment is typically in advance of services, and deferred revenue is created as these services are provided over time. A significant portion of the Company’s contracts have an original duration of one year or less; therefore, the Company applies a practical expedient to determine whether a significant financing component exists and does not consider the effects of the time value of money. For multi-year contracts, the Company bills annually. Transaction price allocated to the remaining performance obligations The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied at the end of the reporting period (in thousands): <1-3 years 3-5 years 5 years or more Total Subscription $ 644,959 $ 74,039 $ 1,148 $ 720,146 Support and services 1,408,910 44,587 1,362 1,454,859 Total net revenues $ 2,053,869 $ 118,626 $ 2,510 $ 2,175,005 Contract acquisition costs The Company is required to capitalize certain contract acquisition costs consisting primarily of commissions paid and related payroll taxes when contracts are signed. The asset recognized from capitalized incremental and recoverable acquisition costs is amortized on a basis consistent with the pattern of transfer of the products or services to which the asset relates. The Company’s typical contracts include performance obligations related to product and licenses and support. In these contracts, incremental costs of obtaining a contract are allocated to the performance obligations based on the relative estimated standalone selling prices and then recognized on a basis that is consistent with the transfer of the goods or services to which the asset relates. The commissions paid on annual renewals of support for product and licenses are not commensurate with the initial commission. The costs allocated to product and licenses are expensed at the time of sale, when revenue for the product and functional software licenses is recognized. The costs allocated to customer support for product and licenses are amortized ratably over a period of the greater of the contract term or the average customer life, the expected period of benefit of the asset capitalized. The Company currently estimates an average customer life of three years to five years , which it believes is appropriate based on consideration of the historical average customer life and the estimated useful life of the underlying product and license sold as part of the transaction. Amortization of contract acquisition costs related to support are limited to the contractual period of the arrangement as the Company intends to pay a commensurate commission upon renewal of the related support. For contracts that contain multi-year services or subscriptions, the amortization period of the capitalized costs is the expected period of benefit, which is the greater of the contractual term or the expected customer life. The Company elects to apply a practical expedient to expense contract acquisition costs as incurred where the expected period of benefit is one year or less. For the three and nine months ended September 30, 2019 , the Company recorded amortization of capitalized contract acquisition costs of $11.4 million and $33.0 million , respectively, and for the three and nine months ended September 30, 2018 , the Company recorded amortization of capitalized contract acquisition costs of $9.5 million and $25.7 million , respectively, which is recorded in Sales, marketing and services expense in the accompanying condensed consolidated statements of income. As of September 30, 2019 , the Company's short-term and long-term contract acquisition costs were $45.0 million and $69.7 million , respectively, and are included in Prepaid and other current assets and Other assets, respectively, in the accompanying condensed consolidated balance sheets. There was no impairment loss in relation to costs capitalized during the three and nine months ended September 30, 2019 and 2018 .

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Basic earnings per share is calculated by dividing income available to stockholders by the weighted-average number of common shares outstanding during each period. Diluted earnings per share is computed using the weighted-average number of common and dilutive common share equivalents outstanding during the period. Dilutive common share equivalents consist of shares issuable upon the exercise or settlement of stock awards and shares issuable under the employee stock purchase plan (calculated using the treasury stock method) during the period they were outstanding and potential dilutive common shares from the conversion spread on the Company’s 0.500% Convertible Notes due 2019 (the “Convertible Notes”) during the period they were outstanding and the Company's warrants. The following table sets forth the computation of basic and diluted net income per share (in thousands, except per share information): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Numerator: Net income $ 270,857 $ 158,857 $ 474,700 $ 409,949 Denominator: Denominator for basic earnings per share - weighted-average shares outstanding 130,277 135,055 131,020 136,752 Effect of dilutive employee stock awards 1,823 2,731 2,050 2,594 Effect of dilutive Convertible Notes — 6,999 1,901 5,892 Effect of dilutive warrants 555 2,783 1,326 1,316 Denominator for diluted earnings per share - weighted-average shares outstanding 132,655 147,568 136,297 146,554 Basic earnings per share $ 2.08 $ 1.18 $ 3.62 $ 3.00 Diluted earnings per share $ 2.04 $ 1.08 $ 3.48 $ 2.80 For the three and nine months ended September 30, 2019 , the weighted-average number of shares outstanding used in the computation of diluted earnings per share includes the dilutive effect of the Company's warrants, as the average stock price during the quarters was above the weighted-average warrant strike price of $94.18 per share and $94.52 per share, respectively. For the three and nine months ended September 30, 2018 , the weighted-average number of shares outstanding used in the computation of diluted earnings per share includes the dilutive effect of the Company's warrants, as the average stock price during the quarters was above the weighted-average warrant strike price of $95.25 per share. Anti-dilutive stock-based awards excluded from the calculations of diluted earnings per share were immaterial during the periods presented. The Company uses the treasury stock method for calculating any potential dilutive effect of the conversion spread on its Convertible Notes on diluted earnings per share because upon conversion the Company paid cash up to the aggregate principal amount of the Convertible Notes converted and delivered shares of common stock in respect of the remainder of the Company’s conversion obligation in excess of the aggregate principal amount of the Convertible Notes converted. The conversion spread had a dilutive impact on diluted earnings per share when the average market price of the Company’s common stock for a given period exceeded the conversion price. For the nine months ended September 30, 2019 and three and nine months ended September 30, 2018 , the average market price of the Company's common stock exceeded the conversion price; therefore, the dilutive effect of the Convertible Notes was included in the denominator of diluted earnings per share. For the three months ended September 30, 2019 , there was no dilution as the Convertible Notes matured on April 15, 2019. See Note 11 for detailed information on the Convertible Notes offering.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS 2018 Business Combinations Sapho, Inc. On November 13, 2018, the Company acquired all of the issued and outstanding securities of Sapho, Inc. (“Sapho”), whose technology is intended to advance the Company’s development of the intelligent workspace. The acquired technology enables efficient workstyles by creating a unified and customizable notification experience for business applications. The total cash consideration for this transaction was $182.7 million , net of $3.7 million cash acquired. Transaction costs associated with the acquisition were not significant. Cedexis, Inc. On February 6, 2018, the Company acquired all of the issued and outstanding securities of Cedexis, Inc. (“Cedexis”), whose solution is a real-time data driven service for dynamically optimizing the flow of traffic across public clouds and data centers that provides a dynamic and reliable way to route and manage Internet performance for customers moving towards hybrid and multi-cloud deployments. The total cash consideration for this transaction was $66.0 million , net of $6.0 million cash acquired. Transaction costs associated with the acquisition were not significant. During the third quarter of 2019, the Company tested certain intangible assets for recoverability due to changes in facts and circumstances associated with the shift in strategic focus and reduced profitability expectations. As a result, the Company impaired a portion of the carrying value of the intangible assets related to this acquisition in the third quarter of 2019. See Note 9 for more information on the impairment.

Investments

Investments	9 Months Ended
	Sep. 30, 2019
Investments [Abstract]
INVESTMENTS	INVESTMENTS Available-for-sale Investments Investments in available-for-sale securities at fair value were as follows for the periods ended (in thousands): September 30, 2019 December 31, 2018 Description of the Securities Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Agency securities $ 1,681 $ — $ (2 ) $ 1,679 $ 314,982 $ 333 $ (2,367 ) $ 312,948 Corporate securities 61,044 1 (160 ) 60,885 612,698 116 (4,156 ) 608,658 Municipal securities — — — — 2,500 4 — 2,504 Government securities 14,179 7 (4 ) 14,182 234,668 91 (935 ) 233,824 Total $ 76,904 $ 8 $ (166 ) $ 76,746 $ 1,164,848 $ 544 $ (7,458 ) $ 1,157,934 The change in net unrealized gains (losses) on available-for-sale securities recorded in Other comprehensive income includes unrealized gains (losses) that arose from changes in market value of specifically identified securities that were held during the period, gains (losses) that were previously unrealized, but have been recognized in current period net income due to sales and other than temporary impairments, as well as prepayments of available-for-sale investments purchased at a premium. See Note 13 for more information related to comprehensive income. The average remaining maturities of the Company’s short-term and long-term available-for-sale investments at September 30, 2019 were approximately five months and two years , respectively. Realized Gains and Losses on Available-for-sale Investments For the three months ended September 30, 2019 , the Company had no proceeds from the sales of available-for-sale investments. For the nine months ended September 30, 2019 , the Company received proceeds from the sales of available-for-sale investments of $938.0 million . For the three and nine months ended September 30, 2018 , the Company received proceeds from the sales of available-for-sale investments of $7.5 million and $442.4 million , respectively. For the three months ended September 30, 2019 , the Company had no realized gains on the sales of available-for-sale investments. For the nine months ended September 30, 2019 , the Company had realized gains on the sales of available-for-sale investments of $1.5 million . For the three months ended September 30, 2018 , the Company had no realized gains on the sales of available-for-sale investments. For the nine months ended September 30, 2018 , the Company had $0.1 million in realized gains on the sales of available-for-sale investments. For the three months ended September 30, 2019 , the Company had no realized losses on available-for-sale investments. For the nine months ended September 30, 2019 , the Company had realized losses on available-for-sale investments of $0.9 million . For the three and nine months ended September 30, 2018 , the Company had realized losses on available-for-sale investments of $0.1 million and $1.5 million , respectively, primarily related to sales of these investments during these periods. All realized gains and losses related to the sales of available-for-sale investments are included in Other income (expense), net , in the accompanying condensed consolidated statements of income. Unrealized Losses on Available-for-Sale Investments The gross unrealized losses on the Company’s available-for-sale investments that are not deemed to be other-than-temporarily impaired as of September 30, 2019 and December 31, 2018 were $0.2 million and $ 2.9 million Equity Securities without Readily Determinable Fair Values The Company held direct investments in privately-held companies of $12.3 million and $13.4 million as of September 30, 2019 and December 31, 2018 , respectively, which are accounted for at cost, less impairment plus or minus adjustments resulting from observable price changes in orderly transactions for an identical or a similar investment of the same issuer. These investments are included in Other assets in the accompanying condensed consolidated balance sheets. The Company periodically reviews these investments for impairment and observable price changes on a quarterly basis, and adjusts the carrying value accordingly. The Company determined that there were no material adjustments resulting from observable price changes to the Company's investments in privately-held companies without a readily determinable fair value for the three and nine months ended September 30, 2019 . The fair value of these investments represents a Level 3 valuation as the assumptions used in valuing these investments are not directly or indirectly observable. See Note 7 for detailed information on fair value measurements. Equity Securities Accounted for at Net Asset Value The Company held equity interests in certain private equity funds of $11.9 million and $10.9 million as of September 30, 2019 and December 31, 2018 , respectively, which are accounted for under the net asset value practical expedient. These investments are included in Other assets in the accompanying condensed consolidated balance sheets. The net asset value of these investments is determined using quarterly capital statements from the funds, which are based on the Company’s contributions to the funds, allocation of profit and loss and changes in fair value of the underlying fund investments. These private equity funds focus on making venture capital investments, principally by investing in equity securities of early and late stage privately held corporations. The funds’ general partner shall determine the amount, timing and form (whether cash or in kind) of all distributions made by the funds. The Company may only transfer its investments in private equity fund interests subject to the general partner’s written consent and cannot trade its fund interests in established securities markets, secondary markets or equivalents thereof. The Company has unfunded commitments of $0.7 million as of September 30, 2019

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The authoritative guidance defines fair value as an exit price, representing the amount that would either be received to sell an asset or be paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: • Level 1. Observable inputs such as quoted prices in active markets for identical assets or liabilities; • Level 2 . Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and • Level 3 . Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Available-for-sale securities included in Level 2 are valued utilizing inputs obtained from an independent pricing service (the “Service”) which uses quoted market prices for identical or comparable instruments rather than direct observations of quoted prices in active markets. The Service applies a four level hierarchical pricing methodology to all of the Company’s fixed income securities based on the circumstances. The hierarchy starts with the highest priority pricing source, then subsequently uses inputs obtained from other third-party sources and large custodial institutions. The Service’s providers utilize a variety of inputs to determine their quoted prices. These inputs may include interest rates, known historical trades, yield curve information, benchmark data, prepayment speeds, credit quality and broker/dealer quotes. Substantially all of the Company’s available-for-sale investments are valued utilizing inputs obtained from the Service and accordingly are categorized as Level 2 in the table below. The Company periodically independently assesses the pricing obtained from the Service and historically has not adjusted the Service's pricing as a result of this assessment. Available-for-sale securities are included in Level 3 when relevant observable inputs for a security are not available. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the classification of assets and liabilities within the fair value hierarchy. In certain instances, the inputs used to measure fair value may meet the definition of more than one level of the fair value hierarchy. The input with the lowest level priority is used to determine the applicable level in the fair value hierarchy. Assets and Liabilities Measured at Fair Value on a Recurring Basis As of September 30, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Assets: Cash and cash equivalents: Cash $ 402,579 $ 402,579 $ — $ — Money market funds 74,863 74,863 — — Corporate securities 16,392 16,392 Available-for-sale securities: Agency securities 1,679 — 1,679 — Corporate securities 60,885 — 59,885 1,000 Government securities 14,182 — 14,182 — Prepaid expenses and other current assets: Foreign currency derivatives 542 — 542 — Total assets $ 571,122 $ 477,442 $ 92,680 $ 1,000 Accrued expenses and other current liabilities: Foreign currency derivatives 2,320 — 2,320 — Total liabilities $ 2,320 $ — $ 2,320 $ — As of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Assets: Cash and cash equivalents: Cash $ 505,363 $ 505,363 $ — $ — Money market funds 88,126 88,126 — — Agency securities 3,296 — 3,296 — Corporate securities 9,371 — 9,371 — Government securities 12,610 — 12,610 — Available-for-sale securities: Agency securities 312,948 — 312,948 — Corporate securities 608,658 — 607,945 713 Municipal securities 2,504 — 2,504 — Government securities 233,824 — 233,824 — Prepaid expenses and other current assets: Foreign currency derivatives 764 — 764 — Total assets $ 1,777,464 $ 593,489 $ 1,183,262 $ 713 Accrued expenses and other current liabilities: Foreign currency derivatives 2,543 — 2,543 — Total liabilities $ 2,543 $ — $ 2,543 $ — The Company’s fixed income available-for-sale security portfolio generally consists of investment grade securities from diverse issuers with a minimum credit rating of A-/A3 and a weighted-average credit rating of AA-/Aa3. The Company values these securities based on pricing from the Service, whose sources may use quoted prices in active markets for identical assets (Level 1 inputs) or inputs other than quoted prices that are observable either directly or indirectly (Level 2 inputs) in determining fair value, and accordingly, the Company classifies the majority of its fixed income available-for-sale securities as Level 2. The Company measures its cash flow hedges, which are classified as Prepaid expenses and other current assets and Accrued expenses and other current liabilities, at fair value based on indicative prices in active markets (Level 2 inputs). Assets Measured at Fair Value on a Non-recurring Basis Using Significant Unobservable Inputs (Level 3) During the three months ended September 30, 2019 , certain direct investments in privately-held companies with a carrying value of $0.5 million were determined to be impaired and written down to their fair value of $0.1 million , resulting in impairment charges of $0.4 million . During the nine months ended September 30, 2019 , certain direct investments in privately-held companies with a carrying value of $2.4 million were determined to be impaired and written down to their fair value of $0.4 million , resulting in impairment charges of $2.0 million . The impairment charges were included in Other income (expense), net in the accompanying condensed consolidated statements of income. During the three months ended September 30, 2018 , no direct investments in privately-held companies were determined to be impaired. During the nine months ended September 30, 2018 , the Company determined that certain direct investments in privately-held companies were impaired and recorded charges of $0.9 million , which were included in Other income (expense), net Additional Disclosures Regarding Fair Value Measurements The carrying value of accounts receivable, accounts payable and accrued expenses approximate their fair value due to the short maturity of these items. As of September 30, 2019 , the fair value of the $750.0 million of unsecured senior notes due December 1, 2027 (the “2027 Notes"), which was determined based on inputs that are observable in the market (Level 2) based on the closing trading price per $100 as of the last day of trading for the quarter ended September 30, 2019 , and carrying value of the 2027 Notes was as follows (in thousands): Fair Value Carrying Value 2027 Notes $ 811,485 $ 742,704

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION The Company’s stock-based compensation program is a long-term retention program that is intended to attract and reward talented employees and align stockholder and employee interests. As of September 30, 2019 , the Company had one stock-based compensation plan under which it was granting equity awards. The Company is currently granting stock-based awards from its Amended and Restated 2014 Equity Incentive Plan (the "2014 Plan"), which was approved at the Company's Annual Meeting of Stockholders on June 22, 2017. In March 2019, the Company's Board of Directors adopted an amendment to the 2014 Plan, which was approved at the Company's Annual Meeting of Stockholders on June 4, 2019. The Company’s superseded stock plans with outstanding awards include the Amended and Restated 2005 Equity Incentive Plan. Under the terms of the 2014 Plan, the Company is authorized to grant incentive stock options (“ISOs”), non-qualified stock options (“NSOs”), non-vested stock, non-vested stock units, stock appreciation rights (“SARs”), and performance units and to make stock-based awards to full and part-time employees of the Company and its subsidiaries or affiliates, where legally eligible to participate, as well as to consultants and non-employee directors of the Company. ISOs, NSOs, and SARs are not currently being granted. Pursuant to the June 2019 amendment, the maximum number of shares of common stock available for issuance under the 2014 Plan was reduced to 43,400,000 . In addition, the amendment removed the fungible share adjustment used to determine shares available for issuance. Under the original terms of the 2014 Plan, shares available for issuance were adjusted by a 2.75 fungible share factor. Pursuant to the amendment, beginning on June 4, 2019, each share award granted under the 2014 Plan reduces the share reserve by one share and all share awards granted on June 4, 2019 and thereafter that are later forfeited, canceled or terminated are returned to the share reserve in the same manner. Under the 2014 Plan, NSOs must be granted at exercise prices no less than fair market value on the date of grant. Non-vested stock awards may be granted for such consideration in cash, other property or services, or a combination thereof, as determined by the Company’s Compensation Committee of its Board of Directors. Stock-based awards are generally exercisable or issuable upon vesting. The Company’s policy is to recognize compensation cost for awards with only service conditions and a graded vesting schedule on a straight-line basis over the requisite service period for the entire award. As of September 30, 2019 , there were 12,411,438 shares of common stock reserved for issuance pursuant to the Company’s stock-based compensation plans including authorization under its 2014 Plan to grant stock-based awards covering 6,129,472 shares of common stock. In December 2014, the Company’s Board of Directors approved the 2015 Employee Stock Purchase Plan (the “2015 ESPP”), which was approved by stockholders at the Company’s Annual Meeting of Stockholders held on May 28, 2015. Under the 2015 ESPP, all full-time and certain part-time employees of the Company are eligible to purchase common stock of the Company twice per year at the end of a six -month payment period (a “Payment Period”). During each Payment Period, eligible employees who so elect may authorize payroll deductions in an amount no less than 1% nor greater than 10% of his or her base pay for each payroll period in the Payment Period. At the end of each Payment Period, the accumulated deductions are used to purchase shares of common stock from the Company up to a maximum of 12,000 shares for any one employee during a Payment Period. Shares are purchased at a price equal to 85% of the fair market value of the Company's common stock, on either the first business day of the Payment Period or the last business day of the Payment Period, whichever is lower. Employees who, after exercising their rights to purchase shares of common stock in the 2015 ESPP, would own shares representing 5% or more of the voting power of the Company’s common stock, are ineligible to continue to participate under the 2015 ESPP. The 2015 ESPP provides for the issuance of a maximum of 16,000,000 shares of common stock. As of September 30, 2019 , 2,192,755 shares have been issued under the 2015 ESPP. The Company recorded stock-based compensation costs related to the 2015 ESPP of $4.0 million and $1.8 million for the three months ended September 30, 2019 and 2018 , respectively, and $9.5 million and $7.3 million for the nine months ended September 30, 2019 and 2018 , respectively. The Company used the Black-Scholes model to estimate the fair value of 2015 ESPP awards with the following weighted-average assumptions: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Expected volatility factor 0.22 - 0.29 0.26 - 0.29 0.22 - 0.29 0.26 - 0.29 Risk free interest rate 2.06% - 2.49% 1.63% - 2.19% 2.06% - 2.49% 1.12% - 2.19% Expected dividend yield 1.31% - 1.39% 0% - 1.27% 1.27% - 1.39% 0% - 1.27% Expected life (in years) 0.5 0.5 0.5 0.5 The Company determined the expected volatility factor by considering the implied volatility in six-month market-traded options of the Company's common stock based on third-party volatility quotes. The Company's decision to use implied volatility was based upon the availability of actively traded options on the Company's common stock and its assessment that implied volatility is more representative of future stock price trends than historical volatility. The risk-free interest rate was based on a U.S. Treasury instrument whose term is consistent with the expected term of the stock options. The Company's historical dividend yield input was zero in prior periods as it had not historically paid cash dividends on its common stock. The current dividend yield has been updated for expected dividend yield payout due to the Company's intention to pay a recurring quarterly dividend beginning in December 2018. The expected term is based on the term of the purchase period for grants made under the ESPP. Stock-Based Compensation The detail of the total stock-based compensation recognized by income statement classification is as follows (in thousands): Three Months Ended Nine Months Ended Income Statement Classifications September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Cost of subscription, support and services $ 2,898 $ 2,106 $ 8,056 $ 5,827 Research and development 25,505 17,009 78,761 45,517 Sales, marketing and services 23,838 18,910 68,188 52,095 General and administrative 16,728 14,714 47,518 40,867 Total $ 68,969 $ 52,739 $ 202,523 $ 144,306 Non-vested Stock Units Market Performance and Service Condition Stock Units In March 2017, the Company granted senior level employees non-vested stock unit awards representing, in the aggregate, 275,148 non-vested stock units that vest based on certain target performance and service conditions. The number of non-vested stock units underlying the award will be determined within sixty days of the three -year performance period ending December 31, 2019. The attainment level under the award will be based on the Company's relative total return to stockholders over the performance period compared to a pre-established custom index group. If the Company’s relative total return to stockholders is between the 41st percentile and the 80th percentile when compared to the index companies, the number of non-vested stock units earned will be based on interpolation. The maximum number of non-vested stock units that may vest pursuant to the awards is capped at 200% of the target number of non-vested stock units set forth in the award agreement and is earned if the Company's relative total return to stockholders when compared to the index companies is at or greater than the 80th percentile. If the Company’s total return to stockholders is negative, the number of non-vested stock units earned will be no more than 100% regardless of the Company’s relative total return to stockholders compared to the index companies. If the awardee is not employed by the Company at the end of the performance period, the extent to which the awardee will vest in the award, if at all, is dependent upon the timing and character of the termination as provided in the award agreement. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company's common stock. In December 2018, certain awards for senior level employees, none of whom were executive officers, were modified to replace the pre-established custom index group used to measure performance and related award payout with companies that are part of the Nasdaq Composite index. As a result, the awards were revalued as of the modification date. The impact of the modification was not material to the condensed consolidated financial statements. The market condition requirements are reflected in the grant date fair value of the award, and the compensation expense for the award will be recognized assuming that the requisite service is rendered regardless of whether the market conditions are achieved. The grant date fair value of the non-vested performance stock unit awards was determined through the use of a Monte Carlo simulation model, which utilized multiple input variables that determined the probability of satisfying the market condition requirements applicable to each award as follows: March 2017 Grant (Modified) March 2017 Grant Expected volatility factor 0.16-0.32 0.27-0.32 Risk free interest rate 2.67 % 1.48 % Expected dividend yield 0 % 0 % For the unmodified March 2017 grant, the range of expected volatilities utilized was based on the historical volatilities of the Company's common stock and the average of its peer group. The Company chose to use historical volatility to value these awards because historical stock prices were used to develop the correlation coefficients between the Company and its peer group in order to model the stock price movements. The volatilities used were calculated over the most recent 2.75 year period, which is commensurate with the awards' performance period at the grant date. The risk free interest rate was based on the implied yield available on U.S. Treasury zero-coupon issues with remaining terms equivalent to the performance period. In addition, the Company used a dividend yield of zero in its model. The estimated fair value of each award as of the date of grant was $104.05 . For the modified March 2017 grant, all input variables chosen are as of the modification date. The range of expected volatilities utilized was based on the historical volatilities of the Company's common stock and the average of the Nasdaq Composite index peer group. The Company chose to use historical volatility to value these awards because historical stock prices were used to develop the correlation coefficients between the Company and its peer group in order to model the stock price movements. The volatilities used were calculated over the most recent 1.06 year period, which is commensurate with the awards' remaining performance period at the modification date. The risk free interest rate was based on the implied yield available on U.S. Treasury zero-coupon issues with remaining terms equivalent to the remaining performance period. The Company used a zero dividend yield input for this award as dividends are assumed to be reinvested. The estimated incremental fair value of each modified award as of the modification date was $99.54 . Service-Based Stock Units The Company also awards senior level employees, certain other employees and new non-employee directors, non-vested stock units granted under the 2014 Plan that vest based on service. The majority of these non-vested stock unit awards generally vest 33.33% on each anniversary subsequent to the date of the award. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company’s common stock. In addition, the Company awards non-vested stock units to all of its continuing non-employee directors. These awards vest monthly in 12 equal installments based on service and, upon vesting, each stock unit represents the right to receive one share of the Company's common stock. Company Performance Stock Units In April 2019, the Company awarded senior level employees 293,991 non-vested performance stock unit awards granted under the 2014 Plan. The number of non-vested stock units underlying the award will be determined within sixty days following completion of the performance period ending December 31, 2021 and will be based on the achievement of specific corporate financial performance goals related to subscription bookings as a percentage of total subscription and product bookings measured during the period from January 1, 2021 to December 31, 2021. The number of non-vested stock units issued will be based on a graduated slope, with the maximum number of non-vested stock units issuable pursuant to the award capped at 200% of the target number of non-vested stock units set forth in the award agreement. The Company is required to estimate the attainment expected to be achieved related to the defined performance goals and the number of non-vested stock units that will ultimately be awarded in order to recognize compensation expense over the vesting period. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company’s common stock. Compensation expense will be recorded through the end of the performance period on December 31, 2021 if it is deemed probable that the performance goals will be met. If the performance goals are not met, no compensation cost will be recognized and any previously recognized compensation cost will be reversed. In February 2019, the Company awarded certain senior level employees 93,500 non-vested performance stock units granted under the 2014 Plan. The number of non-vested stock units underlying the award will be determined within sixty days following the completion of the performance period ending December 31, 2020 and will be based on the achievement of specific corporate financial performance goals related to annual free cash flow per share growth between the fiscal years ended December 31, 2018 and December 31, 2020 . Within sixty days following an interim measurement period of 12 months, the Compensation Committee will determine the number of restricted stock units that would be deemed earned based on performance to date and up to 50% of the target award may be earned based on such performance. However, any stock units that are deemed earned will remain subject to continued service vesting until the end of the performance period, or a change in control, if earlier. The number of non-vested stock units issued will be based on a graduated slope, with the maximum number of non-vested stock units issuable pursuant to the award capped at 200% of the target number of non-vested stock units set forth in the award agreement. The Company is required to estimate the attainment expected to be achieved related to the defined performance goals and the number of non-vested stock units that will ultimately be awarded in order to recognize compensation expense over the vesting period. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company’s common stock. Compensation expense will be recorded through the end of the performance period on December 31, 2020 if it is deemed probable that the performance goals will be met. If the performance goals are not met, no compensation cost will be recognized and any previously recognized compensation cost will be reversed. In March 2018, the Company awarded senior level employees 268,729 non-vested performance stock unit awards granted under the 2014 Plan. The number of non-vested stock units underlying the award will be determined within sixty days following completion of the performance period ending December 31, 2020 and will be based on the achievement of specific corporate financial performance goals related to subscription bookings as a percentage of total product bookings measured during the period from January 1, 2020 to December 31, 2020. As defined in the applicable award agreements, total product bookings includes subscription bookings. The number of non-vested stock units issued will be based on a graduated slope, with the maximum number of non-vested stock units issuable pursuant to the award capped at 200% of the target number of non-vested stock units set forth in the award agreement. The Company is required to estimate the attainment expected to be achieved related to the defined performance goals and the number of non-vested stock units that will ultimately be awarded in order to recognize compensation expense over the vesting period. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company’s common stock. Compensation expense will be recorded through the end of the performance period on December 31, 2020 if it is deemed probable that the performance goals will be met. If the performance goals are not met, no compensation cost will be recognized and any previously recognized compensation cost will be reversed. On August 1, 2017, the Company awarded certain senior level employees 184,322 non-vested performance stock units granted under the 2014 Plan. The number of non-vested stock units underlying each award will be determined within sixty days following completion of the performance period ending December 31, 2019 and will be based on achievement of specific corporate financial performance goals related to non-GAAP net operating margin and subscription bookings as a percent of total product bookings measured during the period from January 1, 2019 to December 31, 2019. As defined in the applicable award agreements, total product bookings includes subscription bookings. The number of non-vested stock units issued will be based on a graduated slope, with the maximum number of non-vested stock units issuable pursuant to the award capped at 200% of the target number of non-vested stock units set forth in the award agreement. The Company is required to estimate the attainment expected to be achieved related to the defined performance goals and the number of non-vested stock units that will ultimately be awarded in order to recognize compensation expense over the vesting period. Each non-vested stock unit, upon vesting, represents the right to receive one share of the Company’s common stock. The non-GAAP net operating margin and subscription bookings as a percent of total product bookings targets were set in the first quarter of 2018. As a result, such awards were not outstanding under U.S. GAAP until the first quarter of 2018 when the performance goals were determined and subsequently communicated to employees who received the awards. Compensation expense will be recorded through the end of the performance period on December 31, 2019 if it is deemed probable that the performance goals will be met. If the performance goals are not met, no compensation cost will be recognized and any previously recognized compensation cost will be reversed. Unrecognized Compensation Related to Stock Units As of September 30, 2019 , the total number of non-vested stock units outstanding, including company performance awards, market performance and service condition awards and service-based awards was 6,233,225 . As of September 30, 2019 , there was $411.3 million of total unrecognized compensation cost related to non-vested stock units. The unrecognized cost of the awards legally granted through September 30, 2019 is expected to be recognized over a weighted-average period of 1.74 years. Modification of Market and Company Performance Stock Units On April 22, 2019, the change in control provisions of the unvested and outstanding March 2017 market performance stock unit awards and the February 2019, March 2018 and August 2017 company performance stock unit awards were modified such that if a change in control were to occur prior to the end of the award’s performance period, the award would be deemed earned at 200% of the target award, subject to time-based vesting and the awardee’s continuous employment through the end of the award’s performance periods. Previously, the change in control provisions of these awards allowed for either pro rata vesting or vesting based on interim performance through the change in control date. No incremental compensation expense was recorded as a result of this modification given the improbable nature of a change in control event.

Goodwill And Other Intangible A

Goodwill And Other Intangible Assets	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLE ASSETS	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill The Company accounts for goodwill in accordance with the authoritative guidance, which requires that goodwill and certain intangible assets are not amortized, but are subject to an annual impairment test. The Company performed a qualitative assessment in connection with its annual goodwill impairment test in the fourth quarter of 2018 . As a result of the qualitative analysis, a quantitative impairment test was not deemed necessary. There was no impairment of goodwill or indefinite lived intangible assets as a result of the annual impairment test analysis completed during the fourth quarter of 2018 . The following table presents the change in goodwill during the nine months ended September 30, 2019 (in thousands): Balance at January 1, 2019 Additions Other Balance at September 30, 2019 Goodwill $ 1,802,670 $ — $ (4,262 ) (1) $ 1,798,408 (1) Amount relates to adjustments to the purchase price allocation associated with 2018 acquisitions. Intangible Assets The Company has intangible assets which were primarily acquired in conjunction with business combinations and technology purchases. Intangible assets with finite lives are recorded at cost, less accumulated amortization. Amortization is computed over the estimated useful lives of the respective assets, generally three to seven years , except for patents, which are amortized over the lesser of their remaining life or seven to ten years . In-process R&D is initially capitalized at fair value as an intangible asset with an indefinite life and assessed for impairment thereafter. When in-process R&D projects are completed, the corresponding amount is reclassified as an amortizable intangible asset and is amortized over the asset's estimated useful life. Intangible assets consist of the following (in thousands): September 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Product related intangible assets $ 732,699 $ 625,000 $ 746,152 $ 601,993 Other 188,773 177,417 227,922 204,894 Total $ 921,472 $ 802,417 $ 974,074 $ 806,887 Amortization and impairment of product-related intangible assets, which consists primarily of product-related technologies and patents, was $22.6 million and $11.6 million for the three months ended September 30, 2019 and 2018 , respectively, and $42.7 million and $34.2 million for the nine months ended September 30, 2019 and 2018 , respectively, and is classified as a component of Cost of net revenues in the accompanying condensed consolidated statements of income. Amortization of other intangible assets, which consist primarily of customer relationships, trade names and covenants not to compete was $4.9 million and $4.1 million for the three months ended September 30, 2019 and 2018 , respectively, and $ 11.7 million for the nine months ended September 30, 2019 and 2018 , respectively, and is classified as a component of Operating expenses in the accompanying condensed consolidated statements of income. The Company monitors its intangible assets for indicators of impairment. If the Company determines impairment has occurred, it will write-down the intangible asset to its fair value. For certain intangible assets where the unamortized balances exceeded the undiscounted future net cash flows, the Company measures the amount of the impairment by calculating the amount by which the carrying values exceed the estimated fair values, which are based on projected discounted future net cash flows. During the three months ended September 30, 2019 , the Company tested certain intangible assets for recoverability and, as a result, identified certain definite-lived intangible assets, primarily Cedexis developed technology, that were impaired and recorded non-cash impairment charges of $13.2 million to write down the intangible assets to their estimated fair value of $4.1 million . The impairment charge is included in Amortization and impairment of product related intangible assets in the accompanying condensed consolidated statements of income. These non-recurring fair value measurements were categorized as Level 3, as significant unobservable inputs were used in the valuation analysis. Key assumptions used in the valuation include forecasts of revenue and expenses over an extended period of time, customer churn rates, rate of migration to future technology, tax rates, and estimated costs of debt and equity capital to discount the projected cash flows. Certain of these assumptions involve significant judgment, are based on management’s estimate of current and forecasted market conditions and are sensitive and susceptible to change; therefore, further disruptions in the business could potentially result in additional amounts becoming impaired. Estimated future amortization expense of intangible assets with finite lives as of September 30, 2019 is as follows (in thousands): Year ending December 31, 2019 (remaining three months) $ 11,495 2020 35,059 2021 22,768 2022 20,569 2023 16,259 Thereafter 12,905 Total $ 119,055

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
SEGMENT INFORMATION	SEGMENT INFORMATION Citrix has one Revenues by product grouping were as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Net revenues: Digital Workspace revenues (1) $ 512,838 $ 508,706 $ 1,562,508 $ 1,467,087 Networking revenues (2) 188,191 195,421 537,628 611,386 Professional services (3) 31,872 28,349 100,605 93,560 Total net revenues $ 732,901 $ 732,476 $ 2,200,741 $ 2,172,033 (1) Digital Workspace revenues are primarily comprised of sales from the Company’s application virtualization solutions, which include Citrix Virtual Apps and Desktops, the Company's unified endpoint management solutions, which include Citrix Endpoint Management, related license updates and maintenance and support, Citrix Content Collaboration and cloud offerings. (2) Networking revenues primarily include Citrix ADC and Citrix SD-WAN, related license updates and maintenance and support and cloud offerings. (3) Professional services revenues are primarily comprised of revenues from consulting services and product training and certification services. The following table presents revenues by geographic location, for the following periods (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Net revenues: Americas $ 418,301 $ 432,689 $ 1,251,729 $ 1,276,873 EMEA 236,081 228,236 713,282 676,942 APJ 78,519 71,551 235,730 218,218 Total net revenues $ 732,901 $ 732,476 $ 2,200,741 $ 2,172,033 As of September 30, 2019 , one distributor, the Arrow Group, accounted for 14% of the Company's total gross accounts receivable. Strategic Service Providers The Company defines Strategic Service Providers (SSP) as its three historically largest hyperscale Networking customers. The following table summarizes SSP revenue for the following periods (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Net revenues: SSP revenue $ 38,475 $ 34,685 $ 84,307 $ 136,168 Non-SSP revenue 694,426 697,791 2,116,434 2,035,865 Total net revenues $ 732,901 $ 732,476 $ 2,200,741 $ 2,172,033 Subscription Revenue Subscription revenue relates to fees which are generally recognized ratably over the contractual term. The Company's subscription revenue includes Software as a Service (SaaS), which primarily consists of subscriptions delivered via a cloud hosted service whereby the customer does not take possession of the software and hybrid subscription offerings; and non-SaaS, which consists primarily of on-premise licensing, hybrid subscription offerings, CSP services and the related support. The Company's hybrid subscription offerings are allocated between SaaS and non-SaaS, which are generally recognized at a point in time. The following table presents subscription revenues by SaaS and non-SaaS components, for the following periods (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Subscription: SaaS $ 100,857 $ 70,768 $ 277,512 $ 195,527 Non-SaaS 59,016 40,771 179,800 129,966 Total Subscription revenue $ 159,873 $ 111,539 $ 457,312 $ 325,493

Debt

Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
DEBT	DEBT Senior Notes On November 15, 2017, the Company issued $750.0 million of unsecured senior notes due December 1, 2027. The 2027 Notes accrue interest at a rate of 4.500% per annum. Interest on the 2027 Notes is due semi-annually on June 1 and December 1 of each year, beginning on June 1, 2018. The net proceeds from this offering were approximately $741.0 million , after deducting the underwriting discount and estimated offering expenses payable by the Company. Net proceeds from this offering were used to repurchase shares of the Company's common stock through an Accelerated Share Repurchase ("ASR") transaction which the Company entered into with Citibank, N.A. (the "ASR Counterparty") on November 13, 2017. The 2027 Notes will mature on December 1, 2027, unless earlier redeemed in accordance with their terms prior to such date. The Company may redeem the 2027 Notes at its option at any time in whole or from time to time in part prior to September 1, 2027 at a redemption price equal to the greater of (i) 100% of the aggregate principal amount of the 2027 Notes to be redeemed and (ii) the sum of the present values of the remaining scheduled payments under such 2027 Notes, plus in each case, accrued and unpaid interest to, but excluding, the redemption date. Among other terms, under certain circumstances, holders of the 2027 Notes may require the Company to repurchase their 2027 Notes upon the occurrence of a change of control prior to maturity for cash at a repurchase price equal to 101% of the principal amount of the 2027 Notes to be repurchased plus accrued and unpaid interest to, but excluding, the repurchase date. Credit Facility Effective January 7, 2015, the Company entered into a credit agreement (the "Credit Agreement") with a group of financial institutions (the “Lenders”). The credit facility provides for a five -year revolving line of credit in the aggregate amount of $250.0 million , subject to continued covenant compliance. The Company may elect to increase the revolving credit facility by up to $250.0 million if existing or new lenders provide additional revolving commitments in accordance with the terms of the Credit Agreement. A portion of the revolving line of credit (i) in the aggregate amount of $25.0 million may be available for issuances of letters of credit and (ii) in the aggregate amount of $10.0 million may be available for swing line loans, as part of, not in addition to, the aggregate revolving commitments. The credit facility bears interest at LIBOR plus 1.10% and adjusts in the range of 1.00% to 1.30% above LIBOR based on the ratio of the Company’s total debt to its adjusted earnings before interest, taxes, depreciation, amortization and certain other items (“EBITDA”) as defined in the Credit Agreement. In addition, the Company is required to pay a quarterly facility fee ranging from 0.125% to 0.20% of the aggregate revolving commitments under the credit facility and based on the ratio of the Company’s total debt to the Company’s consolidated EBITDA. During the three months ended September 30, 2019 , the Company borrowed and repaid $200.0 million under the credit facility. As of September 30, 2019 , there were no amounts outstanding under the credit facility. The Credit Agreement contains certain financial covenants that require the Company to maintain a consolidated leverage ratio of not more than 3.5 : 1.0 and a consolidated interest coverage ratio of not less than 3.0 : 1.0 . In addition, the Credit Agreement contains customary affirmative and negative covenants, including covenants that limit or restrict the ability of the Company to grant liens, merge, dissolve or consolidate, dispose of all or substantially all of its assets, pay dividends during the existence of a default under the Credit Agreement, change its business and incur subsidiary indebtedness, in each case subject to customary exceptions for a credit facility of this size and type. The Company was in compliance with these covenants as of September 30, 2019 . Convertible Notes During 2014, the Company completed a private placement of approximately $1.44 billion principal amount of 0.500% Convertible Notes due 2019. As of October 15, 2018, the Company had received conversion notices from noteholders with respect to $273.0 million in aggregate principal amount of Convertible Notes requesting conversion as a result of the sales price condition having been met during the second and third quarter of 2018. In accordance with the terms of the Convertible Notes, in the fourth quarter of 2018, the Company made cash payments of this aggregate principal amount and delivered 1.3 million newly issued shares of its common stock in respect of the remainder of the Company's conversion obligation in excess of the aggregate principal amount of the Convertible Notes being converted, in full satisfaction of such converted notes. The Company received shares of its common stock under the Bond Hedges (as defined below) that offset the issuance of shares of common stock upon conversion of the Convertible Notes. In addition, on or after October 15, 2018 until the close of business on the second scheduled trading day immediately preceding the April 15, 2019 maturity date, holders of the Convertible Notes had the right to convert their notes at any time, regardless of whether the sales price condition was met. All Convertible Notes were converted by their beneficial owners prior to their maturity on April 15, 2019 . In accordance with the terms of the indenture governing the Convertible Notes, on April 15, 2019 the Company paid $1.16 billion in the outstanding aggregate principal amount of the Convertible Notes and delivered 4.9 million newly issued shares of its common stock in respect of the remainder of the Company's conversion obligation in excess of the aggregate principal amount of the Convertible Notes being converted, in full satisfaction of such converted notes. The Company received shares of its common stock under the Bond Hedges that offset the issuance of shares of common stock upon conversion of the Convertible Notes. In accounting for the settlement of the Convertible Notes, the Company allocated the fair value of the settlement consideration remitted to the noteholders between the liability and equity components. The portion of the settlement consideration allocated to the extinguishment of the liability component was based on the fair value of that component immediately before extinguishment. The Company allocated the remaining settlement consideration to the reacquisition of the equity component and recognized this amount as a reduction of Stockholders' equity. The following table includes total interest expense recognized related to the Convertible Notes and the 2027 Notes (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Contractual interest expense $ 8,438 $ 9,721 $ 26,945 $ 30,283 Amortization of debt issuance costs 182 1,199 1,488 3,578 Amortization of debt discount 41 8,836 8,232 26,312 $ 8,661 $ 19,756 $ 36,665 $ 60,173 See Note 7 to the Company's condensed consolidated financial statements for fair value disclosures related to the Company's 2027 Notes. Convertible Note Hedge and Warrant Transactions To minimize the impact of potential dilution upon conversion of the Convertible Notes, the Company entered into convertible note hedge transactions relating to approximately 16.0 million shares of common stock (the "Bond Hedges") and also entered into separate warrant transactions (the "Warrant Transactions") with each of the Option Counterparties relating to approximately 16.0 million shares of common stock to offset any payments in cash or shares of common stock at the Company’s election. As a result of the spin-off of its GoTo Business, the number of shares of the Company's common stock covered by the Bond Hedges and Warrant Transactions was adjusted to approximately 20.0 million shares. As noted above, the Bond Hedges reduced the dilution upon conversion of the Convertible Notes, as the market price per share of common stock, as measured under the terms of the Bond Hedges, was greater than the strike price of the Bond Hedges, which initially corresponded to the conversion price of the Convertible Notes and was subject to anti-dilution adjustments substantially similar to those applicable to the conversion rate of the Convertible Notes. The Warrant Transactions will separately have a dilutive effect to the extent that the market value per share of common stock, as measured under the terms of the Warrant Transactions, exceeds the applicable strike price of the warrants issued pursuant to the Warrant Transactions (the “Warrants”). The strike price of the Warrants was further adjusted to $93.92 per share and the number of shares of the Company's common stock covered by the remaining Warrant Transactions was adjusted to approximately 11.9 million shares as a result of the cash dividend paid in September 2019. The Warrants expire in ratable portions on a series of expiration dates that commenced on July 15, 2019 and which conclude on November 18, 2019. During the quarter ended September 30, 2019 , 7.0 million Warrants were exercised, and the Company delivered 0.2 million shares of its common stock as the volume weighted average stock price was above the Warrant strike price. Additionally, as of September 30, 2019 , 5.4 million Warrants had expired unexercised on various dates and 7.9 million

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	DERIVATIVE FINANCIAL INSTRUMENTS Derivatives Designated as Hedging Instruments As of September 30, 2019 , the Company’s derivative assets and liabilities primarily resulted from cash flow hedges related to its forecasted operating expenses transacted in local currencies. A substantial portion of the Company’s overseas expenses are and will continue to be transacted in local currencies. To protect against fluctuations in operating expenses and the volatility of future cash flows caused by changes in currency exchange rates, the Company has established a program that uses foreign exchange forward contracts to hedge its exposure to these potential changes. The terms of these instruments, and the hedged transactions to which they relate, generally do not exceed 12 months. Generally, when the dollar is weak, foreign currency denominated expenses will be higher, and these higher expenses will be partially offset by the gains realized from the Company’s hedging contracts. Conversely, if the dollar is strong, foreign currency denominated expenses will be lower. These lower expenses will in turn be partially offset by the losses incurred from the Company’s hedging contracts. Derivative instruments are recognized as either assets or liabilities and are measured at fair value. The accounting for changes in the fair value of a derivative depends on the intended use of the derivative and the resulting designation. Gains and losses on derivatives that are designated as cash flow hedges are initially reported as a component of Accumulated other comprehensive loss and are subsequently recognized in income when the hedged exposure is recognized in income. Gains and losses from changes in fair values of derivatives that are not designated as hedges are recognized in Other income (expense), net . The total cumulative unrealized loss on cash flow derivative instruments was $1.6 million and $1.0 million at September 30, 2019 and December 31, 2018 , respectively, and is included in Accumulated other comprehensive loss in the accompanying condensed consolidated balance sheets. See Note 13 for more information related to comprehensive income. The net unrealized loss as of September 30, 2019 is expected to be recognized in income over the next 12 months at the same time the hedged items are recognized in income. Derivatives not Designated as Hedging Instruments A substantial portion of the Company’s overseas assets and liabilities are and will continue to be denominated in local currencies. To protect against fluctuations in earnings caused by changes in currency exchange rates when remeasuring the Company’s balance sheet, it utilizes foreign exchange forward contracts to hedge its exposure to this potential volatility. These contracts are not designated for hedge accounting treatment under the authoritative guidance. Accordingly, changes in the fair value of these contracts are recorded in Other income (expense), net . Fair Values of Derivative Instruments Asset Derivatives Liability Derivatives (In thousands) September 30, 2019 December 31, 2018 September 30, 2019 December 31, 2018 Derivatives Designated as Hedging Instruments Balance Sheet Location Fair Value Balance Sheet Location Fair Value Balance Sheet Location Fair Value Balance Sheet Location Fair Value Foreign currency forward contracts Prepaid expenses and other current assets $362 Prepaid expenses and other current assets $708 Accrued expenses and other current liabilities $2,102 Accrued expenses and other current liabilities $1,811 Asset Derivatives Liability Derivatives (In thousands) September 30, 2019 December 31, 2018 September 30, 2019 December 31, 2018 Derivatives Not Designated as Hedging Instruments Balance Sheet Location Fair Value Balance Sheet Location Fair Value Balance Sheet Location Fair Value Balance Sheet Location Fair Value Foreign currency forward contracts Prepaid expenses and other current assets $180 Prepaid $56 Accrued expenses and other current liabilities $218 Accrued expenses and other current liabilities $732 The Effect of Derivative Instruments on Financial Performance For the Three Months Ended September 30, (In thousands) Derivatives in Cash Flow Hedging Relationships Amount of Loss Recognized in Other Comprehensive (Loss) Income Location of Gain (Loss) Reclassified Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss 2019 2018 2019 2018 Foreign currency forward contracts $ (1,936 ) $ (451 ) Operating expenses $ 162 $ (1,185 ) For the Nine Months Ended September 30, (In thousands) Derivatives in Cash Flow Hedging Relationships Amount of Loss Recognized in Other Comprehensive (Loss) Income Location of (Loss) Gain Reclassified Amount of (Loss) Gain Reclassified from Accumulated Other Comprehensive Loss 2019 2018 2019 2018 Foreign currency forward contracts $ (610 ) $ (5,398 ) Operating expenses $ (829 ) $ 1,031 For the Three Months Ended September 30, (In thousands) Derivatives Not Designated as Hedging Instruments Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative 2019 2018 Foreign currency forward contracts Other income (expense), net $ 4,108 $ 4,452 For the Nine Months Ended September 30, (In thousands) Derivatives Not Designated as Hedging Instruments Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative 2019 2018 Foreign currency forward contracts Other income (expense), net $ 2,128 $ 8,054 Outstanding Foreign Currency Forward Contracts As of September 30, 2019 , the Company had the following net notional foreign currency forward contracts outstanding (in thousands): Foreign Currency Currency Denomination Australian Dollar AUD 20,300 Brazilian Real BRL 1,900 Pounds Sterling GBP 1,800 Canadian Dollar CAD 2,050 Chinese Yuan Renminbi CNY 59,880 Czech Koruna CZK 78,000 Danish Krone DKK 9,300 Euro EUR 5,564 Hong Kong Dollar HKD 33,700 Indian Rupee INR 599,000 Japanese Yen JPY 78,001 Korean Won KRW 609,000 Singapore Dollar SGD 13,400 Swiss Franc CHF 15,418 Swedish Krona SEK 7,600

Comprehensive Income

Comprehensive Income	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
COMPREHENSIVE INCOME	COMPREHENSIVE INCOME The changes in Accumulated other comprehensive loss by component, net of tax, are as follows: Foreign currency Unrealized loss on available-for-sale securities Unrealized loss on derivative instruments Other comprehensive loss on pension liability Total (In thousands) Balance at December 31, 2018 $ (2,946 ) $ (2,440 ) $ (985 ) $ (1,783 ) $ (8,154 ) Other comprehensive income (loss) before reclassifications — 2,859 (1,439 ) — 1,420 Amounts reclassified from accumulated other comprehensive loss — (577 ) 829 — 252 Net current period other comprehensive income — 2,282 (610 ) — 1,672 Balance at September 30, 2019 $ (2,946 ) $ (158 ) $ (1,595 ) $ (1,783 ) $ (6,482 ) Income tax expense or benefit allocated to each component of other comprehensive loss is not material. Reclassifications out of Accumulated other comprehensive loss are as follows: For the Three Months Ended September 30, 2019 (In thousands) Details about accumulated other comprehensive loss components Amount reclassified from accumulated other comprehensive loss, net of tax Affected line item in the Condensed Consolidated Statements of Income Unrealized net loss on available-for-sale securities $ 7 Other income (expense), net Unrealized net gains on cash flow hedges (162 ) Operating expenses * $ (155 ) For the Nine Months Ended September 30, 2019 (In thousands) Details about accumulated other comprehensive loss components Amount reclassified from accumulated other comprehensive loss, net of tax Affected line item in the Condensed Consolidated Statements of Income Unrealized net gains on available-for-sale securities $ (577 ) Other income (expense), net Unrealized net losses on cash flow hedges 829 Operating expenses * $ 252

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company is required to estimate its income taxes in each of the jurisdictions in which it operates as part of the process of preparing its condensed consolidated financial statements. The Company maintains certain strategic management and operational activities in overseas subsidiaries and its foreign earnings are taxed at rates that are generally lower than in the United States. The Company’s effective tax rate generally differs from the U.S. federal statutory rate primarily due to lower tax rates on earnings generated by the Company’s foreign operations that are taxed primarily in Switzerland. The Company’s effective tax rate was (150.5)% and 0.4% for the three months ended September 30, 2019 and 2018 , respectively. The decrease in the effective tax rate when comparing the three months ended September 30, 2019 to the three months ended September 30, 2018 was primarily due to tax items unique to the period ended September 30, 2019 . These amounts include an estimated income tax benefit of $157.7 million due to the recognition of Swiss deferred tax assets related to the enactment of Switzerland’s Federal Act on Tax Reform and AHV Financing (“TRAF”), as well as a $17.3 million tax benefit attributable to the 2015 U.S. federal income tax return statute of limitations closing during the three months ended September 30, 2019 . The Company’s effective tax rate was (42.3)% and 7.2% for the nine months ended September 30, 2019 and 2018 , respectively. The decrease in the effective tax rate when comparing the nine months ended September 30, 2019 to the nine months ended September 30, 2018 was primarily due to tax items unique to the period ended September 30, 2019 . These amounts include an estimated income tax benefit of $157.7 million due to the recognition of Swiss deferred tax assets related to the enactment of Switzerland’s TRAF, as well as a $17.3 million tax benefit attributable to the 2015 U.S. federal income tax return statute of limitations closing during the three months ended September 30, 2019 . The Company considers the income tax impact of the TRAF to be an estimate based on the Company's current interpretation of the TRAF and is subject to change upon valuation, further legislative guidance and the Swiss tax authority review of the federal tax filing. This additional federal benefit is expected to be fully realized over a 10 year amortization period. Additionally, there may be further updates due to the pending implementation of Swiss tax reform on the cantonal level anticipated in the fourth quarter of 2019 or first quarter of 2020. The Company will review any further issued guidance and continue to evaluate the federal and cantonal income tax impact of tax reform in Switzerland. The Company’s net unrecognized tax benefits totaled $84.3 million and $89.9 million as of September 30, 2019 and December 31, 2018 , respectively. At September 30, 2019 , $57.3 million included in the balance for tax positions would affect the annual effective tax rate if recognized. The Company recognizes interest accrued related to uncertain tax positions and penalties in income tax expense. As of September 30, 2019 , the Company has accrued $4.0 million for the payment of interest. The Company and one or more of its subsidiaries are subject to U.S. federal income taxes in the United States, as well as income taxes of multiple state and foreign jurisdictions. The Company is not currently under examination by the United States Internal Revenue Service. With few exceptions, the Company is generally not subject to examination for state and local income tax, or in non-U.S. jurisdictions, by tax authorities for years prior to 2016 . The Company's U.S. liquidity needs are currently satisfied using cash flows generated from its U.S. operations, borrowings, or both. The Company also utilizes a variety of tax planning strategies in an effort to ensure that its worldwide cash is available in locations in which it is needed. The Company expects to repatriate a substantial portion of its foreign earnings over time, to the extent that the foreign earnings are not restricted by local laws or result in significant incremental costs associated with repatriating the foreign earnings. At September 30, 2019 , the Company had $300.3 million in net deferred tax assets. The authoritative guidance requires a valuation allowance to reduce the deferred tax assets reported if, based on the weight of the evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company reviews deferred tax assets periodically for recoverability and makes estimates and judgments regarding the expected geographic sources of taxable income and gains from investments, as well as tax planning strategies in assessing the need for a valuation allowance. If the estimates and assumptions used in the Company's determination change in the future, the Company could be required to revise its estimates of the valuation allowances against its deferred tax assets and adjust its provisions for additional income taxes. On July 24, 2018, the U.S. Ninth Circuit Court of Appeals overturned the U.S. Tax Court’s unanimous decision in Altera v. Commissioner, where the Tax Court held the Treasury regulation requiring participants in a qualified cost sharing arrangement to share stock-based compensation costs to be invalid. On August 7, 2018, the U.S. Ninth Circuit Court of Appeals, on its own motion, withdrew its July 24, 2018 opinion to allow time for a reconstituted panel to confer. Given the increased uncertainty as to the Ninth Circuit panel's eventual ruling and the impact it will have on the Internal Revenue Service’s ability to challenge the technical merits of the Company's position, the Company accrued amounts for this uncertain tax position as of the year ended December 31, 2018

Treasury Stock

Treasury Stock	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
TREASURY STOCK	TREASURY STOCK Stock Repurchase Program The Company’s Board of Directors authorized an ongoing stock repurchase program, of which $750.0 million was approved in October 2018 and an additional $600.0 million was approved in October 2019. The Company may use the approved dollar authority to repurchase stock at any time until the approved amount is exhausted. The objective of the Company’s stock repurchase program is to improve stockholders’ returns. At September 30, 2019 , approximately $414.0 million was available to repurchase common stock pursuant to the stock repurchase program. All shares repurchased are recorded as treasury stock. A portion of the funds used to repurchase stock over the course of the program was provided by net proceeds from the Convertible Notes and 2027 Notes offerings, as well as proceeds from employee stock awards and the related tax benefit. The Company is authorized to make purchases of its common stock using general corporate funds through open market purchases, pursuant to a Rule 10b5-1 plan or in privately negotiated transactions. In February 2018, the Company entered into an ASR transaction with a counterparty to pay an aggregate of $750.0 million in exchange for the delivery of approximately 6.5 million shares of its common stock based on current market prices. The purchase price per share under the ASR was based on the volume-weighted average price of the Company's common stock during the term of the ASR, less a discount. The ASR was entered into pursuant to the Company's existing share repurchase program. Final settlement of the ASR agreement was completed in April 2018 and the Company received delivery of an additional 1.6 million additional shares of its common stock. During the three months ended September 30, 2019 , the Company expended approximately $103.9 million on open market purchases under the stock repurchase program, repurchasing 1,130,100 shares of common stock at an average price of $91.94 . During the nine months ended September 30, 2019 , the Company expended approximately $353.9 million on open market purchases under the stock repurchase program, repurchasing 3,640,982 shares of common stock at an average price of $97.20 . During the three months ended September 30, 2018 , the Company expended approximately $116.2 million on open market purchases under the stock repurchase program, repurchasing 1.0 million shares of common stock at an average price of $111.11 . During the nine months ended September 30, 2018 , the Company expended approximately $131.2 million on open market purchases under the stock repurchase program, repurchasing 1.2 million shares of common stock at an average price of $110.60 . Shares for Tax Withholding During the three and nine months ended September 30, 2019 , the Company withheld 44,829 shares and 742,946 shares, respectively, from equity awards that vested, totaling $4.2 million and $74.8 million , respectively, to satisfy minimum tax withholding obligations that arose on the vesting of such equity awards. During the three and nine months ended September 30, 2018 , the Company withheld 32,813 shares and 570,589 shares, respectively, from equity awards that vested, totaling $3.7 million and $53.6 million , respectively, to satisfy minimum tax withholding obligations that arose on the vesting of such equity awards. These shares are reflected as treasury stock in the Company’s condensed consolidated balance sheets and the related cash outlays do not reduce the Company’s total stock repurchase authority.

Commitments And Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Matters The Company accrues a liability for legal contingencies when it believes that it is both probable that a liability has been incurred and that it can reasonably estimate the amount of the loss. The Company reviews these accruals and adjusts them to reflect ongoing negotiations, settlements, rulings, advice of legal counsel and other relevant information. To the extent new information is obtained and the Company's views on the probable outcomes of any pending claims, suits, assessments, regulatory investigations, or other legal proceedings change, changes in the Company's accrued liabilities would be recorded in the period in which such determination is made. In addition, in accordance with the relevant authoritative guidance, for matters in which the likelihood of material loss is at least reasonably possible, the Company provides disclosure of the possible loss or range of loss. If a reasonable estimate cannot be made, however, the Company will provide disclosure to that effect. Due to the nature of the Company's business, the Company is subject to patent infringement claims, including current litigation alleging infringement by various Company solutions and services. The Company believes that it has meritorious defenses to the allegations made in its pending litigation and intends to vigorously defend itself; however, it is unable currently to determine the ultimate outcome of these or similar matters or the potential exposure to loss, if any. In addition, the Company is subject to various other legal proceedings, including suits, assessments, regulatory actions and investigations generally arising out of the normal course of business. Although it is difficult to predict the ultimate outcomes of these matters, the Company believes that outcomes that will materially and adversely affect its business, financial position, results of operations or cash flows are reasonably possible but not estimable at this time. The Company was the victim of a previously disclosed cyber attack during which international cyber criminals gained intermittent access to Citrix’s internal network. The Company has conducted an investigation into this incident. The Company’s investigation confirmed that between October 13, 2018 and March 8, 2019, international cyber criminals gained intermittent access to Citrix’s internal network through “password spraying”, and over a limited number of days stole business documents and files from a shared network drive and a drive associated with a web-based tool used in the Company's consulting practice. The shared drive from which documents and files were stolen was used to store current and historical business documents and files, such as human resources and employee records, some of which contained sensitive and personal identification information of the Company's current and former employees and, in some cases, their beneficiaries, dependents and others; customer engagement documents, including consulting services project materials, statements of work and proofs of concept, some of which were also stored on the drive associated with a web-based tool used in the Company's consulting practice; marketing materials; sales and finance documents; contracts and other legal records; and a wide assortment of other company records. The cyber criminals also may have accessed the individual virtual drives of a very limited number of compromised users, accessed the company email accounts of the same very limited number of compromised users, and launched without further exploitation a limited number of internal applications. The Company is completing its review of documents and files that may have been accessed or were stolen in this incident, which include files stolen from the shared network drive and the drive associated with the web-based tool used in the Company's consulting practice, and the accessed documents and files on the individual virtual drives and the Company email accounts of the very limited number of compromised users. The Company’s investigation found no indication that the cyber criminals discovered and exploited any vulnerabilities in the Company’s products or customer cloud services to gain entry, and no indication that the security of any Citrix product or customer cloud service was compromised. The Company found no impact to its financial reporting systems from this cyberattack. Additionally, the Company has taken steps to enhance its internal controls over financial reporting and disclosure controls and procedures related to cyberattacks. Further, the Company has a program of network-security (or cyber risk) insurance policies that, with standard exclusions, insure against the costs of detecting and mitigating cyber breaches, the cost of credit monitoring, and reasonable expenses for defending and settling privacy and network security lawsuits. These policies are subject to a $500,000 self-insured retention and a total insurance limit of $200.0 million . There can be no assurance, however, that this insurance coverage is sufficient to cover this or any other cyberattack. In addition to these insurance policies, the Company maintains customary business coverage under its crime, commercial general liability, and director and officer insurance policies. Although it is difficult to predict the ultimate outcomes of this cyberattack, to date, three putative class action lawsuits have been filed against the Company in the United States District Court for the Southern District of Florida. These matters, Howard v. Citrix, Jackson and Sargent v. Citrix, and Ramus, Young and Charles v. Citrix, were filed on May 24, 2019, May 30, 2019, and June 23, 2019, respectively, and have been consolidated. The plaintiffs, who purport to represent various classes of current and former employees (and their dependents) of the Company, generally claim to have been harmed by the Company’s alleged actions and/or omissions in connection with this incident and their personal data. They assert a variety of common law and statutory claims seeking monetary damages or other related relief. The Company is unable to currently determine the ultimate outcome of these legal proceedings or the potential exposure or loss, if any, because the legal proceedings remain in the early stages, there is uncertainty as to the likelihood of a class or classes being certified or the ultimate size of any class if certified, and there are significant factual and legal issues to be resolved. Beyond the matters described above, the Company believes that it is reasonably possible that outcomes from potential unasserted claims related to this cyberattack could materially and adversely affect its business, financial position, results of operations or cash flows. However, it is not possible to estimate the amount or a range of potential loss, if any, at this time, and the Company will continue to evaluate information as it becomes known, and will record an accrual for estimated losses at the time or times it is determined that a loss is both probable and reasonably estimable. Guarantees The authoritative guidance requires certain guarantees to be recorded at fair value and requires a guarantor to make disclosures, even when the likelihood of making any payments under the guarantee is remote. For those guarantees and indemnifications that do not fall within the initial recognition and measurement requirements of the authoritative guidance, the Company must continue to monitor the conditions that are subject to the guarantees and indemnifications, as required under existing generally accepted accounting principles, to identify if a loss has been incurred. If the Company determines that it is probable that a loss has been incurred, any such estimable loss would be recognized. The initial recognition and measurement requirements do not apply to the provisions contained in the majority of the Company’s software license agreements that indemnify licensees of the Company’s software from damages and costs resulting from claims alleging that the Company’s software infringes the intellectual property rights of a third party. The Company has not made material payments pursuant to these provisions. The Company has not identified any losses that are probable under these provisions and, accordingly, the Company has not recorded a liability related to these indemnification provisions. In June 2019, the Company entered into an amended agreement with a third-party provider, in the ordinary course of business, for the Company's use of certain cloud services through June 2021. Under the amended agreement, the Company is committed to a purchase of $25.0 million in fiscal year 2020.

Restructuring

Restructuring	9 Months Ended
	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
RESTRUCTURING	RESTRUCTURING The Company has implemented multiple restructuring plans to reduce its cost structure, align resources with its product strategy and improve efficiency, which has resulted in workforce reductions and the consolidation of certain leased facilities. For the three and nine months ended September 30, 2019 and 2018 , restructuring charges were comprised of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Employee severance and related costs $ 6,213 $ 22 $ 13,356 $ 2,341 Consolidation of leased facilities 2,666 (508 ) 2,666 10,797 Total Restructuring charges $ 8,879 $ (486 ) $ 16,022 $ 13,138 For the three and nine months ended September 30, 2019, the Company incurred costs related to initiatives intended to accelerate the transformation to a cloud-based subscription business, increase strategic focus, and improve operational efficiency. For the three months ended September 30, 2019 , the Company incurred costs of $6.2 million related to employee severance and related costs and $2.7 million related to the consolidation of leased facilities. For the nine months ended September 30, 2019 , the Company incurred costs of $13.4 million related to employee severance and related costs and $2.7 million related to the consolidation of leased facilities. Total costs incurred for the three months ended September 30, 2018 were not material. During the nine months ended September 30, 2018 , the Company incurred costs of $2.3 million related to employee severance and related costs. In connection with the Company's restructuring initiatives, the Company had previously vacated or consolidated properties and subsequently reassessed its obligations on non-cancelable leases. The fair value estimate of these non-cancelable leases was based on the contractual lease costs over the remaining term, partially offset by estimated future sublease rental income. During the three months ended September 30, 2018 , the Company recorded a credit of $0.5 million as a reversal of the original estimated charge as a result of a reassessment, which decreased restructuring charges related to the lease exit costs. In addition, during the nine months ended September 30, 2018 , the Company incurred costs of $10.8 million related to the consolidation of leased facilities. Restructuring accruals The activity in the Company’s restructuring accruals for the nine months ended September 30, 2019 is summarized as follows (in thousands): Total Balance at January 1, 2019 $ 45,095 Adjustment for ASC 842 (42,248 ) Employee severance and related costs 13,356 Payments (10,507 ) Balance at September 30, 2019 $ 5,696 As of September 30, 2019 , the $5.7 million in outstanding restructuring accruals primarily relate to employee severance and related costs. As a result of the adoption of the new lease standard, the provision for lease losses was reclassified, resulting in a reduction to operating lease right-of-use assets as of January 1, 2019. Refer to Note 2 for additional information on adoption of the lease standard.

Statement of Changes in Equity

Statement of Changes in Equity	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Statement of Changes in Equity	STATEMENT OF CHANGES IN EQUITY The following tables presents the changes in total stockholders' equity during the three and nine months ended September 30, 2019 (in thousands): Common Stock Additional Paid In Capital Retained Earnings Accumulated Other Comprehensive Loss Common Stock in Treasury Total Equity Shares Amount Shares Amount Balance at June 30, 2019 316,969 $ 317 $ 6,078,960 $ 4,277,586 $ (4,610 ) (186,486 ) $ (9,844,231 ) $ 508,022 Shares issued under stock-based compensation plans 123 — — — — — — — Stock-based compensation expense — — 68,969 — — — — 68,969 Common stock issued under employee stock purchase plan 255 1 20,454 — — — — 20,455 Stock repurchases, net — — — — — (1,130 ) (103,905 ) (103,905 ) Restricted shares turned in for tax withholding — — — — — (45 ) (4,242 ) (4,242 ) Cash dividends declared — — — (45,373 ) — — — (45,373 ) Settlement of warrants 202 — — — — — — — Other — — 2,194 (2,194 ) — — — — Other comprehensive loss, net of tax — — — (1,872 ) — — (1,872 ) Net income — — — 270,857 — — — 270,857 Balance at September 30, 2019 317,549 $ 318 $ 6,170,577 $ 4,500,876 $ (6,482 ) (187,661 ) (9,952,378 ) $ 712,911 Common Stock Additional Paid In Capital Retained Earnings Accumulated Other Comprehensive loss Common Stock in Treasury Total Equity Shares Amount Shares Amount Balance at December 31, 2018 309,761 $ 310 $ 5,404,500 $ 4,169,019 $ (8,154 ) (178,327 ) $ (9,014,156 ) $ 551,519 Shares issued under stock-based compensation plans 2,167 2 (2 ) — — — — — Stock-based compensation expense — — 202,523 — — — — 202,523 Temporary equity reclassification — — 8,110 — — — — 8,110 Common stock issued under employee stock purchase plan 471 1 39,470 — — — — 39,471 Stock repurchases, net — — — — — (3,641 ) (353,904 ) (353,904 ) Restricted shares turned in for tax withholding — — — — — (743 ) (74,794 ) (74,794 ) Cash dividends declared — — — (137,224 ) — — — (137,224 ) Settlement of convertible notes and hedges 4,950 5 509,519 — — (4,950 ) (509,524 ) — Settlement of warrants 202 — — — — — — — Cumulative-effect adjustment from adoption of accounting standard — — — 838 — — — 838 Other (2 ) — 6,457 (6,457 ) — — — — Other comprehensive income, net of tax — — — — 1,672 — — 1,672 Net income — — — 474,700 — — — 474,700 Balance at September 30, 2019 317,549 $ 318 $ 6,170,577 $ 4,500,876 $ (6,482 ) (187,661 ) $ (9,952,378 ) $ 712,911 The following tables presents the changes in total stockholders' equity during the three and nine months ended September 30, 2018 (in thousands): Common Stock Additional Paid In Capital Retained Earnings Accumulated Other Comprehensive loss Common Stock in Treasury Total Equity Shares Amount Shares Amount Balance at June 30, 2018 307,662 $ 308 $ 5,116,339 $ 3,893,354 $ (18,718 ) (172,244 ) $ (8,355,107 ) $ 636,176 Shares issued under stock-based compensation plans 110 — 50 — — — — 50 Stock-based compensation expense — — 52,739 — — — — 52,739 Temporary equity reclassification — — 8,796 — — — — 8,796 Common stock issued under employee stock purchase plan 209 — 16,004 — — — — 16,004 Stock repurchases, net — — — — — (1,046 ) (116,175 ) (116,175 ) Restricted shares turned in for tax withholding — — — — — (32 ) (3,654 ) (3,654 ) Other comprehensive income, net of tax — — — — 427 — — 427 Net income — — — 158,857 — — — 158,857 Balance at September 30, 2018 307,981 $ 308 $ 5,193,928 $ 4,052,211 $ (18,291 ) (173,322 ) $ (8,474,936 ) $ 753,220 Common Stock Additional Paid In Capital Retained Earnings Accumulated Other Comprehensive loss Common Stock in Treasury Total Equity Shares Amount Shares Amount Balance at December 31, 2017 305,751 $ 306 $ 4,883,670 $ 3,509,484 $ (10,806 ) (162,044 ) $ (7,390,193 ) $ 992,461 Shares issued under stock-based compensation plans 1,769 2 162 — — — — 164 Stock-based compensation expense — — 145,920 — — — — 145,920 Temporary equity reclassification — — (19,286 ) — — — — (19,286 ) Common stock issued under employee stock purchase plan 461 — 33,462 — — — — 33,462 Stock repurchases, net — — 150,000 — — (10,708 ) (1,031,154 ) (881,154 ) Restricted shares turned in for tax withholding — — — — — (570 ) (53,589 ) (53,589 ) Cumulative-effect adjustment from adoption of accounting standards — — — 132,778 — — — 132,778 Other comprehensive loss, net of tax — — — — (7,485 ) — — (7,485 ) Net income — — — 409,949 — — — 409,949 Balance at September 30, 2018 307,981 $ 308 $ 5,193,928 $ 4,052,211 $ (18,291 ) (173,322 ) $ (8,474,936 ) $ 753,220 Cash Dividend The following table provides information with respect to quarterly dividends on common stock during the nine months ended September 30, 2019 . Declaration Date Dividends per Share Record Date Payable Date January 23, 2019 $ 0.35 March 8, 2019 March 22, 2019 April 24, 2019 $ 0.35 June 7, 2019 June 21, 2019 July 24, 2019 $ 0.35 September 6, 2019 September 20, 2019 Subsequent Event On October 24, 2019 the Company announced that its Board of Directors approved a quarterly cash dividend of $0.35 per share which will be paid on December 20, 2019 to all shareholders of record as of the close of business on December 6, 2019.

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	LEASES The Company leases certain office space and equipment under various leases. In addition to rent, the leases require the Company to pay for taxes, insurance, maintenance and other operating expenses. The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use assets, accrued expenses and other current liabilities, and operating lease liabilities in the Company’s condensed consolidated balance sheets. Finance leases are included in property and equipment, net, accrued expenses and other current liabilities and other long-term liabilities in the Company’s condensed consolidated balance sheets. Finance leases were not material to the condensed consolidated financial statements as of September 30, 2019 . ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at the later of the adoption date of the new standard or the commencement date. The lease liability is based on the present value of lease payments over the lease term (or the remaining term in the case of existing leases at time the Company adopted ASC 842). The Company uses the implicit rate when readily determinable. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The operating lease ROU asset is based on the lease liability, subject to adjustment, such as for initial direct costs, and excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that it will exercise that option. For most operating leases, expense for lease payments is recognized on a straight-line basis over the lease term. Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Company recognizes lease expense for these leases on a straight-line basis over the lease term. The Company has lease agreements with lease components (e.g., fixed payments including rent, real estate taxes and insurance costs) and non-lease components (e.g., common-area maintenance costs), which are generally accounted for as a single lease component, such as for real estate leases. For certain equipment leases, such as colocation facilities, the Company accounts for the lease and non-lease components separately. The components of lease expense were as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2019 Classification Operating lease cost Operating expenses $ 12,599 $ 37,376 Variable lease cost Operating expenses 2,748 7,566 Sublease income Other income (expense), net (236 ) (667 ) Net lease cost $ 15,111 $ 44,275 Supplemental cash flow information related to leases was as follows (in thousands): Nine Months Ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 41,199 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 52,179 Lease Term and Discount Rate September 30, 2019 Weighted-average remaining lease term (years) Operating leases 6.2 Weighted-average discount rate Operating leases 5.00 % Maturities of lease liabilities as of September 30, 2019 were as follows (in thousands): Year ending December 31, Operating Leases 2019 (remaining three months) $ 11,907 2020 61,054 2021 52,483 2022 44,406 2023 40,931 After 2023 102,716 Total lease payments $ 313,497 Less: imputed interest (45,136 ) Present value of lease liabilities $ 268,361 Supplemental balance sheet information related to leases was as follows (in thousands): Operating Leases September 30, 2019 Operating lease right-of-use assets $ 218,625 Accrued expenses and other current liabilities $ 47,329 Operating lease liabilities 221,032 Total operating lease liabilities $ 268,361

Significant Accounting Polici_2

Significant Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Leases In February 2016, the Financial Accounting Standards Board issued an accounting standard update on the accounting for leases (“ASC 842”). The new guidance requires that lessees in a leasing arrangement recognize a right-of-use (“ROU”) asset and a lease liability for most leases (other than leases that meet the definition of a short-term lease). The Company adopted this standard as of January 1, 2019 using a modified retrospective approach and recognized a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. In addition, the Company elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed the Company to carry forward the historical lease classification and not reassess whether any expired or existing contract is a lease or contains a lease. Adoption of this standard had a material impact in the Company’s condensed consolidated balance sheets, but did not have a material impact on its condensed consolidated income statements. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while the Company's accounting for finance leases remained substantially unchanged. Adoption of the new standard resulted in the recording of additional right-of-use assets for operating leases (net of previously recorded lease losses related to the consolidation of leased facilities of $42.2 million and deferred rent liability of $20.5 million under the old guidance) of approximately $194.5 million and operating lease liabilities of approximately $256.4 million , as of January 1, 2019. The difference between the additional lease assets and lease liabilities, net of the deferred tax impact, was recorded as an adjustment to retained earnings of $0.8 million . Adoption of this standard had no impact to cash from or used in operating, financing, or investing in the Company’s condensed consolidated cash flows statements. Adoption of this standard had no impact on the Company's debt covenant compliance under its current agreement or on liquidity. See Note 19 for additional information regarding the Company’s leases. Current Expected Credit Losses In June 2016, the Financial Accounting Standards Board issued an accounting standard update on the measurement of credit losses on financial instruments. Previously, credit losses were measured using an incurred loss approach when it was probable that a credit loss had been incurred. The new guidance changes the credit loss model from an incurred loss to an expected loss approach. It requires the application of a current expected credit loss (“CECL”) impairment model to financial assets measured at amortized cost (including trade accounts receivable) and certain off-balance-sheet credit exposures. Under the CECL model, lifetime expected credit losses on such financial assets are measured and recognized at each reporting date based on historical, current, and forecasted information. The standard also changes the impairment model for available-for-sale debt securities, eliminating the concept of other than temporary impairment and requiring credit losses to be recorded through an allowance for credit losses. The amount of the allowance for credit losses for available-for-sale debt securities is limited to the amount by which fair value is below amortized cost. The standard is effective for interim and annual periods beginning after December 15, 2019. Early adoption is permitted. A modified retrospective adoption method is required, with a cumulative-effect adjustment to the opening retained earnings balance in the period of adoption. The adoption of this standard is not expected to have a material impact on the Company's condensed consolidated financial position, results of operations and cash flows. Additionally, the Company is not planning to early adopt this standard. Premium Amortization on Call Debt Securities In March 2017, the Financial Accounting Standards Board issued an accounting standard update on the accounting for amortization of premium costs on purchased callable debt securities. The new guidance amends the amortization period for certain purchased callable debt securities held at a premium, shortening such period to the earliest call date. The standard does not require any accounting change for debt securities held at a discount; the discount continues to be amortized to maturity. The Company adopted the standard effective January 1, 2019 on a modified retrospective basis. The adoption of this standard did not have a material impact on the Company's condensed consolidated financial position, results of operations and cash flows. Accounting for Cloud Computing Costs In August 2018, the Financial Accounting Standards Board issued an accounting standard update on the accounting for implementation costs incurred by customers in cloud computing arrangements that are service contracts. The new guidance aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The Company early adopted this standard on a prospective basis effective January 1, 2019. Adoption of this standard did not have a material impact on the Company's condensed consolidated financial position, results of operations and cash flows. Fair Value Measurements
Use of Estimates	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 amounts reported in the condensed consolidated financial statements and accompanying notes. Significant estimates made by management include the standalone selling price related to revenue recognition, the provision for doubtful accounts receivable, the provision to reduce obsolete or excess inventory to market, the provision for estimated returns, as well as sales allowances, the assumptions used in the valuation of stock-based awards, the assumptions used in the discounted cash flows to mark certain of its investments to market, the valuation of the Company’s goodwill, net realizable value of product related and other intangible assets, the provision for income taxes, valuation allowance for deferred tax assets, uncertain tax positions, and the amortization and depreciation periods for contract acquisition costs, intangible and long-lived assets. While the Company believes that such estimates are fair when considered in conjunction with the condensed consolidated financial position and results of operations taken as a whole, the actual amounts of such items, when known, will vary from these estimates.
Available-for-sale Investments	Available-for-sale Investments Short-term and long-term available-for-sale investments in debt securities as of September 30, 2019 and December 31, 2018 primarily consist of agency securities, corporate securities, municipal securities and government securities. Investments classified as available-for-sale debt securities are stated at fair value with unrealized gains and losses, net of taxes, reported in Accumulated other comprehensive loss. The Company classifies its available-for-sale investments as current and non-current based on their actual remaining time to maturity. The Company does not recognize changes in the fair value of its available-for-sale investments in income unless a decline in value is considered other-than-temporary in accordance with the authoritative guidance. The Company’s investment policy is designed to limit exposure to any one issuer depending on credit quality. The Company uses information provided by third parties to adjust the carrying value of certain of its investments to fair value at the end of each period. Fair values are based on a variety of inputs and may include interest rates, known historical trades, yield curve information, benchmark data, prepayment speeds, credit quality and broker/dealer quotes. See Note 6 for additional information regarding the Company’s investments.
Foreign Currency	Foreign Currency The functional currency for all of the Company’s wholly-owned foreign subsidiaries is the U.S. dollar. Monetary assets and liabilities of such subsidiaries are remeasured into U.S. dollars at exchange rates in effect at the balance sheet date, and revenues and expenses are remeasured at average rates prevailing during the year.
Accounting for Stock-Based Compensation Plans	Accounting for Stock-Based Compensation Plans The Company has various stock-based compensation plans for its employees and outside directors and accounts for stock-based compensation arrangements in accordance with the authoritative guidance, which requires the Company to measure and record compensation expense in its condensed consolidated financial statements using a fair value method. See Note 8 for further information regarding the Company’s stock-based compensation plans.

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Summary of Performance Obligations	The Company’s typical performance obligations include the following: Performance Obligation When Performance Obligation is Typically Satisfied Subscription Cloud hosted offerings Over the contract term, beginning on the date that service is made available to the customer (over time) CSP As the usage occurs (over time) On-premise subscription software licenses When software activation keys have been made available for download (point in time) Product and license Software Licenses When software activation keys have been made available for download (point in time) Hardware When control of the product passes to the customer; typically upon shipment (point in time) Support and services License updates and maintenance Ratably over the course of the service term (over time) Professional services As the services are provided (over time)
Disaggregation of Revenue	Timing of revenue recognition Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (In thousands) Products and services transferred at a point in time $ 159,326 $ 186,039 $ 500,450 $ 583,888 Products and services transferred over time 573,575 546,437 1,700,291 1,588,145 Total net revenues $ 732,901 $ 732,476 $ 2,200,741 $ 2,172,033
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied at the end of the reporting period (in thousands): <1-3 years 3-5 years 5 years or more Total Subscription $ 644,959 $ 74,039 $ 1,148 $ 720,146 Support and services 1,408,910 44,587 1,362 1,454,859 Total net revenues $ 2,053,869 $ 118,626 $ 2,510 $ 2,175,005

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Income Per Share Basic And Diluted	The following table sets forth the computation of basic and diluted net income per share (in thousands, except per share information): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Numerator: Net income $ 270,857 $ 158,857 $ 474,700 $ 409,949 Denominator: Denominator for basic earnings per share - weighted-average shares outstanding 130,277 135,055 131,020 136,752 Effect of dilutive employee stock awards 1,823 2,731 2,050 2,594 Effect of dilutive Convertible Notes — 6,999 1,901 5,892 Effect of dilutive warrants 555 2,783 1,326 1,316 Denominator for diluted earnings per share - weighted-average shares outstanding 132,655 147,568 136,297 146,554 Basic earnings per share $ 2.08 $ 1.18 $ 3.62 $ 3.00 Diluted earnings per share $ 2.04 $ 1.08 $ 3.48 $ 2.80

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2019
Investments [Abstract]
Schedule of investments in available-for-sale securities at fair values	Investments in available-for-sale securities at fair value were as follows for the periods ended (in thousands): September 30, 2019 December 31, 2018 Description of the Securities Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Agency securities $ 1,681 $ — $ (2 ) $ 1,679 $ 314,982 $ 333 $ (2,367 ) $ 312,948 Corporate securities 61,044 1 (160 ) 60,885 612,698 116 (4,156 ) 608,658 Municipal securities — — — — 2,500 4 — 2,504 Government securities 14,179 7 (4 ) 14,182 234,668 91 (935 ) 233,824 Total $ 76,904 $ 8 $ (166 ) $ 76,746 $ 1,164,848 $ 544 $ (7,458 ) $ 1,157,934

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Assets And Liabilities Measured At Fair Value On A Recurring Basis	Assets and Liabilities Measured at Fair Value on a Recurring Basis As of September 30, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Assets: Cash and cash equivalents: Cash $ 402,579 $ 402,579 $ — $ — Money market funds 74,863 74,863 — — Corporate securities 16,392 16,392 Available-for-sale securities: Agency securities 1,679 — 1,679 — Corporate securities 60,885 — 59,885 1,000 Government securities 14,182 — 14,182 — Prepaid expenses and other current assets: Foreign currency derivatives 542 — 542 — Total assets $ 571,122 $ 477,442 $ 92,680 $ 1,000 Accrued expenses and other current liabilities: Foreign currency derivatives 2,320 — 2,320 — Total liabilities $ 2,320 $ — $ 2,320 $ — As of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Assets: Cash and cash equivalents: Cash $ 505,363 $ 505,363 $ — $ — Money market funds 88,126 88,126 — — Agency securities 3,296 — 3,296 — Corporate securities 9,371 — 9,371 — Government securities 12,610 — 12,610 — Available-for-sale securities: Agency securities 312,948 — 312,948 — Corporate securities 608,658 — 607,945 713 Municipal securities 2,504 — 2,504 — Government securities 233,824 — 233,824 — Prepaid expenses and other current assets: Foreign currency derivatives 764 — 764 — Total assets $ 1,777,464 $ 593,489 $ 1,183,262 $ 713 Accrued expenses and other current liabilities: Foreign currency derivatives 2,543 — 2,543 — Total liabilities $ 2,543 $ — $ 2,543 $ —
Fair Value, by Balance Sheet Grouping	As of September 30, 2019 , the fair value of the $750.0 million of unsecured senior notes due December 1, 2027 (the “2027 Notes"), which was determined based on inputs that are observable in the market (Level 2) based on the closing trading price per $100 as of the last day of trading for the quarter ended September 30, 2019 , and carrying value of the 2027 Notes was as follows (in thousands): Fair Value Carrying Value 2027 Notes $ 811,485 $ 742,704

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions	The Company used the Black-Scholes model to estimate the fair value of 2015 ESPP awards with the following weighted-average assumptions: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Expected volatility factor 0.22 - 0.29 0.26 - 0.29 0.22 - 0.29 0.26 - 0.29 Risk free interest rate 2.06% - 2.49% 1.63% - 2.19% 2.06% - 2.49% 1.12% - 2.19% Expected dividend yield 1.31% - 1.39% 0% - 1.27% 1.27% - 1.39% 0% - 1.27% Expected life (in years) 0.5 0.5 0.5 0.5
Schedule of Total Stock-based Compensation Recognized by Income Statement Classification	The detail of the total stock-based compensation recognized by income statement classification is as follows (in thousands): Three Months Ended Nine Months Ended Income Statement Classifications September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 Cost of subscription, support and services $ 2,898 $ 2,106 $ 8,056 $ 5,827 Research and development 25,505 17,009 78,761 45,517 Sales, marketing and services 23,838 18,910 68,188 52,095 General and administrative 16,728 14,714 47,518 40,867 Total $ 68,969 $ 52,739 $ 202,523 $ 144,306
Schedule of Assumptions Used to Value Nonvested Share Grants	The grant date fair value of the non-vested performance stock unit awards was determined through the use of a Monte Carlo simulation model, which utilized multiple input variables that determined the probability of satisfying the market condition requirements applicable to each award as follows: March 2017 Grant (Modified) March 2017 Grant Expected volatility factor 0.16-0.32 0.27-0.32 Risk free interest rate 2.67 % 1.48 % Expected dividend yield 0 % 0 %

Goodwill And Other Intangible_2

Goodwill And Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule Of The Change In Goodwill	The following table presents the change in goodwill during the nine months ended September 30, 2019 (in thousands): Balance at January 1, 2019 Additions Other Balance at September 30, 2019 Goodwill $ 1,802,670 $ — $ (4,262 ) (1) $ 1,798,408 (1) Amount relates to adjustments to the purchase price allocation associated with 2018 acquisitions.
Schedule Of Intangible Assets	Intangible assets consist of the following (in thousands): September 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Product related intangible assets $ 732,699 $ 625,000 $ 746,152 $ 601,993 Other 188,773 177,417 227,922 204,894 Total $ 921,472 $ 802,417 $ 974,074 $ 806,887
Schedule Of Estimated Future Amortization Expense	Estimated future amortization expense of intangible assets with finite lives as of September 30, 2019 is as follows (in thousands): Year ending December 31, 2019 (remaining three months) $ 11,495 2020 35,059 2021 22,768 2022 20,569 2023 16,259 Thereafter 12,905 Total $ 119,055

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Revenues by Product Grouping	Revenues by product grouping were as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Net revenues: Digital Workspace revenues (1) $ 512,838 $ 508,706 $ 1,562,508 $ 1,467,087 Networking revenues (2) 188,191 195,421 537,628 611,386 Professional services (3) 31,872 28,349 100,605 93,560 Total net revenues $ 732,901 $ 732,476 $ 2,200,741 $ 2,172,033 (1) Digital Workspace revenues are primarily comprised of sales from the Company’s application virtualization solutions, which include Citrix Virtual Apps and Desktops, the Company's unified endpoint management solutions, which include Citrix Endpoint Management, related license updates and maintenance and support, Citrix Content Collaboration and cloud offerings. (2) Networking revenues primarily include Citrix ADC and Citrix SD-WAN, related license updates and maintenance and support and cloud offerings. (3) Professional services revenues are primarily comprised of revenues from consulting services and product training and certification services.
Revenues by Geographic Location	The following table presents revenues by geographic location, for the following periods (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Net revenues: Americas $ 418,301 $ 432,689 $ 1,251,729 $ 1,276,873 EMEA 236,081 228,236 713,282 676,942 APJ 78,519 71,551 235,730 218,218 Total net revenues $ 732,901 $ 732,476 $ 2,200,741 $ 2,172,033
Schedule of Revenue by Major Customers	The Company defines Strategic Service Providers (SSP) as its three historically largest hyperscale Networking customers. The following table summarizes SSP revenue for the following periods (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Net revenues: SSP revenue $ 38,475 $ 34,685 $ 84,307 $ 136,168 Non-SSP revenue 694,426 697,791 2,116,434 2,035,865 Total net revenues $ 732,901 $ 732,476 $ 2,200,741 $ 2,172,033
Schedule of Subscription Revenues	The following table presents subscription revenues by SaaS and non-SaaS components, for the following periods (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Subscription: SaaS $ 100,857 $ 70,768 $ 277,512 $ 195,527 Non-SaaS 59,016 40,771 179,800 129,966 Total Subscription revenue $ 159,873 $ 111,539 $ 457,312 $ 325,493

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Interest Expense Recognized Related to Convertible Notes	The following table includes total interest expense recognized related to the Convertible Notes and the 2027 Notes (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Contractual interest expense $ 8,438 $ 9,721 $ 26,945 $ 30,283 Amortization of debt issuance costs 182 1,199 1,488 3,578 Amortization of debt discount 41 8,836 8,232 26,312 $ 8,661 $ 19,756 $ 36,665 $ 60,173

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule Of The Fair Values Of Derivative Instruments	Fair Values of Derivative Instruments Asset Derivatives Liability Derivatives (In thousands) September 30, 2019 December 31, 2018 September 30, 2019 December 31, 2018 Derivatives Designated as Hedging Instruments Balance Sheet Location Fair Value Balance Sheet Location Fair Value Balance Sheet Location Fair Value Balance Sheet Location Fair Value Foreign currency forward contracts Prepaid expenses and other current assets $362 Prepaid expenses and other current assets $708 Accrued expenses and other current liabilities $2,102 Accrued expenses and other current liabilities $1,811 Asset Derivatives Liability Derivatives (In thousands) September 30, 2019 December 31, 2018 September 30, 2019 December 31, 2018 Derivatives Not Designated as Hedging Instruments Balance Sheet Location Fair Value Balance Sheet Location Fair Value Balance Sheet Location Fair Value Balance Sheet Location Fair Value Foreign currency forward contracts Prepaid expenses and other current assets $180 Prepaid $56 Accrued expenses and other current liabilities $218 Accrued expenses and other current liabilities $732
Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss)	The Effect of Derivative Instruments on Financial Performance For the Three Months Ended September 30, (In thousands) Derivatives in Cash Flow Hedging Relationships Amount of Loss Recognized in Other Comprehensive (Loss) Income Location of Gain (Loss) Reclassified Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss 2019 2018 2019 2018 Foreign currency forward contracts $ (1,936 ) $ (451 ) Operating expenses $ 162 $ (1,185 ) For the Nine Months Ended September 30, (In thousands) Derivatives in Cash Flow Hedging Relationships Amount of Loss Recognized in Other Comprehensive (Loss) Income Location of (Loss) Gain Reclassified Amount of (Loss) Gain Reclassified from Accumulated Other Comprehensive Loss 2019 2018 2019 2018 Foreign currency forward contracts $ (610 ) $ (5,398 ) Operating expenses $ (829 ) $ 1,031
Schedule Of Effect Of Derivative Instruments On Financial Performance	For the Three Months Ended September 30, (In thousands) Derivatives Not Designated as Hedging Instruments Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative 2019 2018 Foreign currency forward contracts Other income (expense), net $ 4,108 $ 4,452 For the Nine Months Ended September 30, (In thousands) Derivatives Not Designated as Hedging Instruments Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative 2019 2018 Foreign currency forward contracts Other income (expense), net $ 2,128 $ 8,054
Schedule Of Net Notional Foreign Currency Forward Contracts Outstanding	As of September 30, 2019 , the Company had the following net notional foreign currency forward contracts outstanding (in thousands): Foreign Currency Currency Denomination Australian Dollar AUD 20,300 Brazilian Real BRL 1,900 Pounds Sterling GBP 1,800 Canadian Dollar CAD 2,050 Chinese Yuan Renminbi CNY 59,880 Czech Koruna CZK 78,000 Danish Krone DKK 9,300 Euro EUR 5,564 Hong Kong Dollar HKD 33,700 Indian Rupee INR 599,000 Japanese Yen JPY 78,001 Korean Won KRW 609,000 Singapore Dollar SGD 13,400 Swiss Franc CHF 15,418 Swedish Krona SEK 7,600

Comprehensive Income (Tables)

Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Schedule of changes in accumulated other comprehensive income by component	The changes in Accumulated other comprehensive loss by component, net of tax, are as follows: Foreign currency Unrealized loss on available-for-sale securities Unrealized loss on derivative instruments Other comprehensive loss on pension liability Total (In thousands) Balance at December 31, 2018 $ (2,946 ) $ (2,440 ) $ (985 ) $ (1,783 ) $ (8,154 ) Other comprehensive income (loss) before reclassifications — 2,859 (1,439 ) — 1,420 Amounts reclassified from accumulated other comprehensive loss — (577 ) 829 — 252 Net current period other comprehensive income — 2,282 (610 ) — 1,672 Balance at September 30, 2019 $ (2,946 ) $ (158 ) $ (1,595 ) $ (1,783 ) $ (6,482 )
Schedule of reclassification out of accumulated other comprehensive income	Reclassifications out of Accumulated other comprehensive loss are as follows: For the Three Months Ended September 30, 2019 (In thousands) Details about accumulated other comprehensive loss components Amount reclassified from accumulated other comprehensive loss, net of tax Affected line item in the Condensed Consolidated Statements of Income Unrealized net loss on available-for-sale securities $ 7 Other income (expense), net Unrealized net gains on cash flow hedges (162 ) Operating expenses * $ (155 ) For the Nine Months Ended September 30, 2019 (In thousands) Details about accumulated other comprehensive loss components Amount reclassified from accumulated other comprehensive loss, net of tax Affected line item in the Condensed Consolidated Statements of Income Unrealized net gains on available-for-sale securities $ (577 ) Other income (expense), net Unrealized net losses on cash flow hedges 829 Operating expenses * $ 252

Restructuring (Tables)

Restructuring (Tables)	9 Months Ended
	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Charges by Segment	For the three and nine months ended September 30, 2019 and 2018 , restructuring charges were comprised of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Employee severance and related costs $ 6,213 $ 22 $ 13,356 $ 2,341 Consolidation of leased facilities 2,666 (508 ) 2,666 10,797 Total Restructuring charges $ 8,879 $ (486 ) $ 16,022 $ 13,138
Schedule of Restructuring Accruals	The activity in the Company’s restructuring accruals for the nine months ended September 30, 2019 is summarized as follows (in thousands): Total Balance at January 1, 2019 $ 45,095 Adjustment for ASC 842 (42,248 ) Employee severance and related costs 13,356 Payments (10,507 ) Balance at September 30, 2019 $ 5,696

Statement of Changes in Equity

Statement of Changes in Equity (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Schedule of Stockholders Equity	The following tables presents the changes in total stockholders' equity during the three and nine months ended September 30, 2019 (in thousands): Common Stock Additional Paid In Capital Retained Earnings Accumulated Other Comprehensive Loss Common Stock in Treasury Total Equity Shares Amount Shares Amount Balance at June 30, 2019 316,969 $ 317 $ 6,078,960 $ 4,277,586 $ (4,610 ) (186,486 ) $ (9,844,231 ) $ 508,022 Shares issued under stock-based compensation plans 123 — — — — — — — Stock-based compensation expense — — 68,969 — — — — 68,969 Common stock issued under employee stock purchase plan 255 1 20,454 — — — — 20,455 Stock repurchases, net — — — — — (1,130 ) (103,905 ) (103,905 ) Restricted shares turned in for tax withholding — — — — — (45 ) (4,242 ) (4,242 ) Cash dividends declared — — — (45,373 ) — — — (45,373 ) Settlement of warrants 202 — — — — — — — Other — — 2,194 (2,194 ) — — — — Other comprehensive loss, net of tax — — — (1,872 ) — — (1,872 ) Net income — — — 270,857 — — — 270,857 Balance at September 30, 2019 317,549 $ 318 $ 6,170,577 $ 4,500,876 $ (6,482 ) (187,661 ) (9,952,378 ) $ 712,911 Common Stock Additional Paid In Capital Retained Earnings Accumulated Other Comprehensive loss Common Stock in Treasury Total Equity Shares Amount Shares Amount Balance at December 31, 2018 309,761 $ 310 $ 5,404,500 $ 4,169,019 $ (8,154 ) (178,327 ) $ (9,014,156 ) $ 551,519 Shares issued under stock-based compensation plans 2,167 2 (2 ) — — — — — Stock-based compensation expense — — 202,523 — — — — 202,523 Temporary equity reclassification — — 8,110 — — — — 8,110 Common stock issued under employee stock purchase plan 471 1 39,470 — — — — 39,471 Stock repurchases, net — — — — — (3,641 ) (353,904 ) (353,904 ) Restricted shares turned in for tax withholding — — — — — (743 ) (74,794 ) (74,794 ) Cash dividends declared — — — (137,224 ) — — — (137,224 ) Settlement of convertible notes and hedges 4,950 5 509,519 — — (4,950 ) (509,524 ) — Settlement of warrants 202 — — — — — — — Cumulative-effect adjustment from adoption of accounting standard — — — 838 — — — 838 Other (2 ) — 6,457 (6,457 ) — — — — Other comprehensive income, net of tax — — — — 1,672 — — 1,672 Net income — — — 474,700 — — — 474,700 Balance at September 30, 2019 317,549 $ 318 $ 6,170,577 $ 4,500,876 $ (6,482 ) (187,661 ) $ (9,952,378 ) $ 712,911 The following tables presents the changes in total stockholders' equity during the three and nine months ended September 30, 2018 (in thousands): Common Stock Additional Paid In Capital Retained Earnings Accumulated Other Comprehensive loss Common Stock in Treasury Total Equity Shares Amount Shares Amount Balance at June 30, 2018 307,662 $ 308 $ 5,116,339 $ 3,893,354 $ (18,718 ) (172,244 ) $ (8,355,107 ) $ 636,176 Shares issued under stock-based compensation plans 110 — 50 — — — — 50 Stock-based compensation expense — — 52,739 — — — — 52,739 Temporary equity reclassification — — 8,796 — — — — 8,796 Common stock issued under employee stock purchase plan 209 — 16,004 — — — — 16,004 Stock repurchases, net — — — — — (1,046 ) (116,175 ) (116,175 ) Restricted shares turned in for tax withholding — — — — — (32 ) (3,654 ) (3,654 ) Other comprehensive income, net of tax — — — — 427 — — 427 Net income — — — 158,857 — — — 158,857 Balance at September 30, 2018 307,981 $ 308 $ 5,193,928 $ 4,052,211 $ (18,291 ) (173,322 ) $ (8,474,936 ) $ 753,220 Common Stock Additional Paid In Capital Retained Earnings Accumulated Other Comprehensive loss Common Stock in Treasury Total Equity Shares Amount Shares Amount Balance at December 31, 2017 305,751 $ 306 $ 4,883,670 $ 3,509,484 $ (10,806 ) (162,044 ) $ (7,390,193 ) $ 992,461 Shares issued under stock-based compensation plans 1,769 2 162 — — — — 164 Stock-based compensation expense — — 145,920 — — — — 145,920 Temporary equity reclassification — — (19,286 ) — — — — (19,286 ) Common stock issued under employee stock purchase plan 461 — 33,462 — — — — 33,462 Stock repurchases, net — — 150,000 — — (10,708 ) (1,031,154 ) (881,154 ) Restricted shares turned in for tax withholding — — — — — (570 ) (53,589 ) (53,589 ) Cumulative-effect adjustment from adoption of accounting standards — — — 132,778 — — — 132,778 Other comprehensive loss, net of tax — — — — (7,485 ) — — (7,485 ) Net income — — — 409,949 — — — 409,949 Balance at September 30, 2018 307,981 $ 308 $ 5,193,928 $ 4,052,211 $ (18,291 ) (173,322 ) $ (8,474,936 ) $ 753,220
Quarterly Dividends on Common Stock	The following table provides information with respect to quarterly dividends on common stock during the nine months ended September 30, 2019 . Declaration Date Dividends per Share Record Date Payable Date January 23, 2019 $ 0.35 March 8, 2019 March 22, 2019 April 24, 2019 $ 0.35 June 7, 2019 June 21, 2019 July 24, 2019 $ 0.35 September 6, 2019 September 20, 2019

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Lease Cost	The components of lease expense were as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2019 Classification Operating lease cost Operating expenses $ 12,599 $ 37,376 Variable lease cost Operating expenses 2,748 7,566 Sublease income Other income (expense), net (236 ) (667 ) Net lease cost $ 15,111 $ 44,275
Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases was as follows (in thousands): Nine Months Ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 41,199 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 52,179
Lease Term and Discount Rate	Lease Term and Discount Rate September 30, 2019 Weighted-average remaining lease term (years) Operating leases 6.2 Weighted-average discount rate Operating leases 5.00 %
Maturity of Operating Lease Liabilities	Maturities of lease liabilities as of September 30, 2019 were as follows (in thousands): Year ending December 31, Operating Leases 2019 (remaining three months) $ 11,907 2020 61,054 2021 52,483 2022 44,406 2023 40,931 After 2023 102,716 Total lease payments $ 313,497 Less: imputed interest (45,136 ) Present value of lease liabilities $ 268,361
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases was as follows (in thousands): Operating Leases September 30, 2019 Operating lease right-of-use assets $ 218,625 Accrued expenses and other current liabilities $ 47,329 Operating lease liabilities 221,032 Total operating lease liabilities $ 268,361

Basis of Presentation (Details)

Basis of Presentation (Details)	9 Months Ended
	Sep. 30, 2019segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	1

Significant Accounting Polici_3

Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Accounting Policies [Abstract]
Lease losses related to consolidation of leased assets		$ (42,248)		$ 42,200
Deferred rent liability				20,500
Operating lease right-of-use assets	$ 194,500	218,625		$ 0
Operating lease liabilities	256,400	268,361
Adjustment to retained earnings	$ 800	$ 838	$ 132,778

Revenue (Details)

Revenue (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total net revenues	$ 732,901,000	$ 732,476,000	$ 2,200,741,000	$ 2,172,033,000
Short-term contract assets	9,100,000		9,100,000		$ 4,600,000
Long-term contract assets	17,600,000		17,600,000		3,700,000
Short-term contract liabilities	1,200,496,000		1,200,496,000		1,345,243,000
Long-term portion of deferred revenues	415,076,000		415,076,000		$ 489,329,000
Deferred revenue recognized	478,700,000		1,130,000,000
Impairment charges related to contract assets	0	0	0	0
Short-term contract acquisition costs	45,000,000		45,000,000
Long-term contract acquisition costs	69,700,000		69,700,000
Impairment of capitalized costs	0	0	0	0
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Total net revenues	159,326,000	186,039,000	500,450,000	583,888,000
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Total net revenues	573,575,000	546,437,000	$ 1,700,291,000	1,588,145,000
Minimum [Member]
Disaggregation of Revenue [Line Items]
Intangible asset life			3 years
Maximum [Member]
Disaggregation of Revenue [Line Items]
Intangible asset life			7 years
Customer Relationships [Member] | Minimum [Member]
Disaggregation of Revenue [Line Items]
Intangible asset life			3 years
Customer Relationships [Member] | Maximum [Member]
Disaggregation of Revenue [Line Items]
Intangible asset life			5 years
Sales, Marketing and Services Expense [Member]
Disaggregation of Revenue [Line Items]
Amortization of capitalized contract acquisition costs	$ 11,400,000	$ 9,500,000	$ 33,000,000	$ 25,700,000

Revenue - Remaining Performance

Revenue - Remaining Performance Obligations (Details)	Sep. 30, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01 | Subscription [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01 | Support and Services [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01 | Subscription [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01 | Support and Services [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01 | Subscription [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01 | Support and Services [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period

Revenue - Remaining Performan_2

Revenue - Remaining Performance Obligation Revenue (Details) $ in Thousands	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 2,053,869
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	118,626
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	2,510
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	2,175,005
Subscription [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	644,959
Subscription [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	74,039
Subscription [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	1,148
Subscription [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	720,146
Support and Services [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	1,408,910
Support and Services [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	44,587
Support and Services [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	1,362
Support and Services [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1,454,859

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2014
Numerator:
Net income	$ 270,857	$ 158,857	$ 474,700	$ 409,949
Denominator:
Denominator for basic net earnings per share - weighted-average shares outstanding (shares)	130,277	135,055	131,020	136,752
Effect of dilutive employee stock awards (shares)	1,823	2,731	2,050	2,594
Effect of dilutive Convertible Notes (shares)	0	6,999	1,901	5,892
Effect of dilutive warrants (shares)	555	2,783	1,326	1,316
Denominator for net diluted earnings per share - weighted-average shares outstanding (shares)	132,655	147,568	136,297	146,554
Basic earnings per share (in dollars per share)	$ 2.08	$ 1.18	$ 3.62	$ 3
Diluted earnings per share (in dollars per share)	$ 2.04	1.08	$ 3.48	$ 2.80
Senior Notes Due 2019 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stated interest rate percentage	0.50%		0.50%		0.50%
Weighted-average warrant strike price (in USD per share)	$ 94.18	$ 95.25	$ 94.52

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) - USD ($) $ in Thousands	Nov. 13, 2018	Feb. 06, 2018	Sep. 30, 2019	Sep. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Cash paid for acquisitions, net of cash acquired			$ 0	$ 65,983
Sapho, Inc. [Member]
Finite-Lived Intangible Assets [Line Items]
Cash paid for acquisitions, net of cash acquired	$ 182,700
Cash acquired in business combination	$ 3,700
Cedexis, Inc. [Member]
Finite-Lived Intangible Assets [Line Items]
Cash paid for acquisitions, net of cash acquired		$ 66,000
Cash acquired in business combination		$ 6,000

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Investment [Line Items]
Average remaining maturities for short-term available for sale investments			5 months
Average remaining maturities for long-term available for sale investments			2 years
Proceeds from available-for-sale of investments	$ 0	$ 7.5	$ 938	$ 442.4
Available-for-sale investments not deemed to be other-than-temporarily impaired	0.2		0.2		$ 2.9
Unfunded commitments	0.7		0.7
Private Equity Funds [Member]
Investment [Line Items]
Alternative Investment	11.9		11.9		10.9
Other Income (Expense) [Member]
Investment [Line Items]
Realized gains on sales of available-for-sale investments	0	0	1.5	0.1
Realized losses on available-for-sale securities	0	$ 0.1	0.9	$ 1.5
Other Assets [Member]
Investment [Line Items]
Direct investments in privately-held companies	$ 12.3		$ 12.3		$ 13.4

Investments (Schedule of Availa

Investments (Schedule of Available-for-sale Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 76,904	$ 1,164,848
Gross Unrealized Gains	8	544
Gross Unrealized Losses	(166)	(7,458)
Fair Value	76,746	1,157,934
Agency securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,681	314,982
Gross Unrealized Gains	0	333
Gross Unrealized Losses	(2)	(2,367)
Fair Value	1,679	312,948
Corporate securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	61,044	612,698
Gross Unrealized Gains	1	116
Gross Unrealized Losses	(160)	(4,156)
Fair Value	60,885	608,658
Municipal securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	0	2,500
Gross Unrealized Gains	0	4
Gross Unrealized Losses	0	0
Fair Value	0	2,504
Government securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	14,179	234,668
Gross Unrealized Gains	7	91
Gross Unrealized Losses	(4)	(935)
Fair Value	$ 14,182	$ 233,824

Fair Value Measurements (Assets

Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Total assets	$ 477,442	$ 593,489
Liabilities, Fair Value Disclosure [Abstract]
Total liabilities	0	0
Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Total assets	92,680	1,183,262
Liabilities, Fair Value Disclosure [Abstract]
Total liabilities	2,320	2,543
Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Total assets	1,000	713
Liabilities, Fair Value Disclosure [Abstract]
Total liabilities	0	0
Cash and Cash Equivalents [Member] | Cash [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	402,579	505,363
Cash and Cash Equivalents [Member] | Cash [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Cash and Cash Equivalents [Member] | Cash [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Cash and Cash Equivalents [Member] | Money Market Funds [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	74,863	88,126
Cash and Cash Equivalents [Member] | Money Market Funds [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Cash and Cash Equivalents [Member] | Money Market Funds [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Cash and Cash Equivalents [Member] | Corporate Securities [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		0
Cash and Cash Equivalents [Member] | Corporate Securities [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	16,392	9,371
Cash and Cash Equivalents [Member] | Corporate Securities [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		0
Cash and Cash Equivalents [Member] | Agency Securities [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		0
Cash and Cash Equivalents [Member] | Agency Securities [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		3,296
Cash and Cash Equivalents [Member] | Agency Securities [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		0
Cash and Cash Equivalents [Member] | Government securities [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		0
Cash and Cash Equivalents [Member] | Government securities [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		12,610
Cash and Cash Equivalents [Member] | Government securities [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		0
Available-for-sale Securities [Member] | Corporate Securities [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale Securities [Member] | Corporate Securities [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	59,885	607,945
Available-for-sale Securities [Member] | Corporate Securities [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	1,000	713
Available-for-sale Securities [Member] | Agency Securities [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale Securities [Member] | Agency Securities [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	1,679	312,948
Available-for-sale Securities [Member] | Agency Securities [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale Securities [Member] | Municipal securities [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities		0
Available-for-sale Securities [Member] | Municipal securities [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities		2,504
Available-for-sale Securities [Member] | Municipal securities [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities		0
Available-for-sale Securities [Member] | Government securities [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale Securities [Member] | Government securities [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	14,182	233,824
Available-for-sale Securities [Member] | Government securities [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member] | Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Prepaid expenses and other current assets	0	0
Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member] | Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Prepaid expenses and other current assets	542	764
Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member] | Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Prepaid expenses and other current assets	0	0
Foreign Exchange Contract [Member] | Accrued Expenses and Other Current Liabilities [Member] | Level 1 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency derivatives	0	0
Foreign Exchange Contract [Member] | Accrued Expenses and Other Current Liabilities [Member] | Level 2 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency derivatives	2,320	2,543
Foreign Exchange Contract [Member] | Accrued Expenses and Other Current Liabilities [Member] | Level 3 [Member]
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency derivatives	0	0
Estimate of Fair Value Measurement [Member]
Assets, Fair Value Disclosure [Abstract]
Total assets	571,122	1,777,464
Liabilities, Fair Value Disclosure [Abstract]
Total liabilities	2,320	2,543
Estimate of Fair Value Measurement [Member] | Cash and Cash Equivalents [Member] | Cash [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	402,579	505,363
Estimate of Fair Value Measurement [Member] | Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	74,863	88,126
Estimate of Fair Value Measurement [Member] | Cash and Cash Equivalents [Member] | Corporate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	16,392	9,371
Estimate of Fair Value Measurement [Member] | Cash and Cash Equivalents [Member] | Agency Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		3,296
Estimate of Fair Value Measurement [Member] | Cash and Cash Equivalents [Member] | Government securities [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		12,610
Estimate of Fair Value Measurement [Member] | Available-for-sale Securities [Member] | Corporate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	60,885	608,658
Estimate of Fair Value Measurement [Member] | Available-for-sale Securities [Member] | Agency Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	1,679	312,948
Estimate of Fair Value Measurement [Member] | Available-for-sale Securities [Member] | Municipal securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities		2,504
Estimate of Fair Value Measurement [Member] | Available-for-sale Securities [Member] | Government securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	14,182	233,824
Estimate of Fair Value Measurement [Member] | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Assets, Fair Value Disclosure [Abstract]
Prepaid expenses and other current assets	542	764
Estimate of Fair Value Measurement [Member] | Foreign Exchange Contract [Member] | Accrued Expenses and Other Current Liabilities [Member]
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency derivatives	$ 2,320	$ 2,543

Fair Value Measurements (Asse_2

Fair Value Measurements (Assets and Liabilities on a Nonrecurring Basis) (Details) - Nonrecurring [Member] - Level 3 [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying amount of direct investments in privately-held companies, impaired during the period	$ 0.5		$ 2.4
Estimated fair value of direct investments in privately-held companies	0.1		0.4
Other (Expense) Income, Net [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge	$ 0.4	$ 0	$ 2	$ 0.9

Fair Value Measurements (Additi

Fair Value Measurements (Additional Information Regarding Fair Value Measurements) (Details) - USD ($)	Sep. 30, 2019	Nov. 15, 2017
Senior Notes Due 2019 [Member] | Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Closing trading price per $100 as of the last day of trading for the quarter	$ 100
Unsecured Debt [Member] | 2027 Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, face amount	750,000,000	$ 750,000,000
Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Value	742,704,000
Senior Notes [Member] | Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 811,485,000

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details)	Apr. 22, 2019USD ($)	Aug. 01, 2017shares	Apr. 30, 2019shares	Feb. 28, 2019shares	Mar. 31, 2018shares	Mar. 31, 2017$ / sharesshares	Sep. 30, 2019USD ($)planshares	Mar. 31, 2019	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)installmentplanshares	Sep. 30, 2018USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans offered | plan							1			1
Stock-based compensation cost | $							$ 68,969,000		$ 52,739,000	$ 202,523,000	$ 144,306,000
Market Performance and Service Condition Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested stock unit awards granted to senior level employees (shares)						275,148
Minimum return to shareholders as percentile of peer group to reach target share cap, minimum						80.00%
Total return to shareholders as percentile of peer group, minimum						41.00%
Total return to shareholders as percentile of peer group, maximum						80.00%
Performance share earned share cap based on maximum shareholder return (percent)						100.00%
Performance share earned share cap based on minimum shareholder return (percent)						200.00%
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period for grants						3 years
Performance share earned share cap based on minimum shareholder return (percent)			200.00%		200.00%
Performance share period to determine actual stock grant following end of interim measurement period		60 days	60 days	60 days	60 days	60 days
Performance share interim measurement period				12 months
Maximum percent of target award that can be earned based on interim performance period (percent)				50.00%
Maximum Percentage of Market and Service Condition Stock Units That will Ultimately Vest		200.00%
Non-vested Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)						2 years 9 months
The estimated fair value of each award (in dollars per share) | $ / shares						$ 104.05
Share based awards granted and outstanding (shares)							6,233,225			6,233,225
Total unrecognized compensation cost related to stock-based compensation | $							$ 411,300,000			$ 411,300,000
Total unrecognized compensation cost recognition period										1 year 8 months 26 days
Non-vested Stock Unit Awards, Modified Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)						1 year 21 days
The estimated fair value of each award (in dollars per share) | $ / shares						$ 99.54
Market Performance Stock Units and Company Performance Stock Units, Change in Control Modification [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation cost | $	$ 0
Maximum percentage of market and service condition stock units that will ultimately vest with change of control (percent)	200.00%
2014 Plan [Member] | Non-vested Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares per non-vested stock unit										1
Stock-based compensation award vesting period, number of monthly installments | installment										12
2014 Plan [Member] | Annual vesting on each anniversary [Member] | Non-vested Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage										33.33%
2015 ESPP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance under the Plan (shares)							16,000,000			16,000,000
Employee Stock Purchase Plan, payment period										6 months
Employee Stock Purchase Plan, maximum number of shares per period that employees can purchase										12,000
Employee Stock Purchase Plan, purchase price as a percentage of fair market value										85.00%
Employee Stock Purchase Plan, employee disqualification, ownership percent of outstanding stock										5.00%
Employee Stock Purchase Plan, total shares issued under plan (shares)							2,192,755			2,192,755
Expected life (in years)							6 months		6 months	6 months	6 months
2015 ESPP Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Purchase Plan, option to purchase shares through payroll deduction, payroll deduction amount per pay period per employee, as a percentage of base pay										1.00%
2015 ESPP Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Purchase Plan, option to purchase shares through payroll deduction, payroll deduction amount per pay period per employee, as a percentage of base pay										10.00%
ESPPs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation cost | $							$ 4,000,000		$ 1,800,000	$ 9,500,000	$ 7,300,000
Common Stock [Member] | 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance under the Plan (shares)							43,400,000			43,400,000
Fungible share factor under original terms of the Plan								2.75
Shares reserved for issuance under the stock-based compensation plans (shares)							12,411,438			12,411,438
Shares available for grant under the 2014 Plan (shares)							6,129,472			6,129,472
Senior Level Employees [Member] | Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested stock unit awards granted to senior level employees (shares)		184,322	293,991	93,500	268,729

Stock-Based Compensation (Assum

Stock-Based Compensation (Assumptions Used To Value Option Grants, Stock Awards and ESPP Shares) (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Non-vested Stock Unit Awards, Modified Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Risk free interest rate	2.67%
Expected dividend yield	0.00%
Expected life (in years)	1 year 21 days
Non-vested Stock Unit Awards, Modified Grant [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor	16.00%
Non-vested Stock Unit Awards, Modified Grant [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor	32.00%
Non-vested Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Risk free interest rate	1.48%
Expected dividend yield	0.00%
Expected life (in years)	2 years 9 months
Non-vested Stock Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor	27.00%
Non-vested Stock Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor	32.00%
2015 ESPP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected life (in years)		6 months	6 months	6 months	6 months
2015 ESPP Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor		22.00%	26.00%	22.00%	26.00%
Risk free interest rate		2.06%	1.63%	2.06%	1.12%
Expected dividend yield		1.31%	0.00%	1.27%	0.00%
2015 ESPP Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor		29.00%	29.00%	29.00%	29.00%
Risk free interest rate		2.49%	2.19%	2.49%	2.19%
Expected dividend yield		1.39%	1.27%	1.39%	1.27%

Stock-Based Compensation (Detai

Stock-Based Compensation (Detail Of The Total Stock-Based Compensation Recognized By Income Statement Classification) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 68,969	$ 52,739	$ 202,523	$ 144,306
Cost of subscription, support and services revenues [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	2,898	2,106	8,056	5,827
Research and development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	25,505	17,009	78,761	45,517
Sales, marketing and services [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	23,838	18,910	68,188	52,095
General and administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 16,728	$ 14,714	$ 47,518	$ 40,867

Goodwill And Other Intangible_3

Goodwill And Other Intangible Assets (Schedule Of Change In Goodwill) (Details) - USD ($)		3 Months Ended	9 Months Ended
		Dec. 31, 2018	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment of goodwill and intangible assets		$ 0
Goodwill [Roll Forward]
Balance at January 1, 2019			$ 1,802,670,000
Additions			0
Other	[1]		(4,262,000)
Balance at September 30, 2019		$ 1,802,670,000	$ 1,798,408,000
[1]	Amount relates to adjustments to the purchase price allocation associated with 2018 acquisitions.

Goodwill And Other Intangible_4

Goodwill And Other Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Intangible Assets [Abstract]
Gross carrying amount	$ 921,472		$ 921,472		$ 974,074
Accumulated amortization	802,417		802,417		806,887
Fair value of definite-lived intangible assets	119,055		119,055
Product Related Intangible Assets [Member]
Intangible Assets [Abstract]
Gross carrying amount	732,699		732,699		746,152
Accumulated amortization	625,000		625,000		601,993
Other [Member]
Intangible Assets [Abstract]
Gross carrying amount	188,773		188,773		227,922
Accumulated amortization	177,417		177,417		$ 204,894
Primarily Cedexis Developed Technology [Member]
Intangible Assets [Abstract]
Non-cash impairment charges	13,200
Fair value of definite-lived intangible assets	4,100		$ 4,100
Minimum [Member]
Statement [Line Items]
Intangible asset life			3 years
Minimum [Member] | Patents [Member]
Statement [Line Items]
Intangible asset life			7 years
Maximum [Member]
Statement [Line Items]
Intangible asset life			7 years
Maximum [Member] | Patents [Member]
Statement [Line Items]
Intangible asset life			10 years
Cost of net revenues [Member] | Product Related Intangible Assets [Member]
Intangible Assets [Abstract]
Amortization expense	22,600	$ 11,600	$ 42,700	$ 34,200
Operating Expense [Member] | Other [Member]
Intangible Assets [Abstract]
Amortization expense	$ 4,900	$ 4,100	$ 11,700	$ 11,700

Goodwill And Other Intangible_5

Goodwill And Other Intangible Assets (Schedule Of Estimated Future Amortization Expense) (Details) $ in Thousands	Sep. 30, 2019USD ($)
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2019 (remaining three months)	$ 11,495
2020	35,059
2021	22,768
2022	20,569
2023	16,259
Thereafter	12,905
Total	$ 119,055

Segment Information (Additional

Segment Information (Additional Information) (Details)	9 Months Ended
	Sep. 30, 2019segmentcustomerdistributor
Concentration Risk [Line Items]
Number of reportable segments | segment	1
Arrow Group [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Number of significant customers | distributor	1
Percent of gross accounts receivable (percent)	14.00%
Strategic Service Provider [Member]
Concentration Risk [Line Items]
Number of significant customers | customer	3

Segment Information (Revenues B

Segment Information (Revenues By Product Grouping) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue		$ 732,901	$ 732,476	$ 2,200,741	$ 2,172,033
Digital Workspace [Member]
Segment Reporting Information [Line Items]
Revenue	[1]	512,838	508,706	1,562,508	1,467,087
Networking revenues [Member]
Segment Reporting Information [Line Items]
Revenue	[2]	188,191	195,421	537,628	611,386
Professional Services [Member]
Segment Reporting Information [Line Items]
Revenue	[3]	$ 31,872	$ 28,349	$ 100,605	$ 93,560
[1]	Digital Workspace revenues are primarily comprised of sales from the Company’s application virtualization solutions, which include Citrix Virtual Apps and Desktops, the Company's unified endpoint management solutions, which include Citrix Endpoint Management, related license updates and maintenance and support, Citrix Content Collaboration and cloud offerings.
[2]	Networking revenues primarily include Citrix ADC and Citrix SD-WAN, related license updates and maintenance and support and cloud offerings.
[3]	Professional services revenues are primarily comprised of revenues from consulting services and product training and certification services.

Segment Information (Revenues_2

Segment Information (Revenues By Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 732,901	$ 732,476	$ 2,200,741	$ 2,172,033
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	418,301	432,689	1,251,729	1,276,873
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	236,081	228,236	713,282	676,942
APJ [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 78,519	$ 71,551	$ 235,730	$ 218,218

Segment Information (Revenue by

Segment Information (Revenue by Customer Type) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue, Major Customer [Line Items]
Revenue	$ 732,901	$ 732,476	$ 2,200,741	$ 2,172,033
Strategic Service Provider [Member]
Revenue, Major Customer [Line Items]
Revenue	38,475	34,685	84,307	136,168
Non-strategic Service Provider [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 694,426	$ 697,791	$ 2,116,434	$ 2,035,865

Segment Information (Subscripti

Segment Information (Subscription Revenues) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total Subscription revenue	$ 732,901	$ 732,476	$ 2,200,741	$ 2,172,033
Subscription [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	159,873	111,539	457,312	325,493
Subscription, SaaS [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	100,857	70,768	277,512	195,527
Subscription, Non-SaaS [Member]
Segment Reporting Information [Line Items]
Total Subscription revenue	$ 59,016	$ 40,771	$ 179,800	$ 129,966

Debt (Narrative) (Details)

Debt (Narrative) (Details)	Apr. 15, 2019USD ($)shares	Nov. 15, 2017USD ($)	Jan. 07, 2015USD ($)	Apr. 30, 2014shares	Sep. 30, 2019USD ($)$ / sharesshares	Dec. 31, 2018shares	Sep. 30, 2019USD ($)$ / sharesshares	Sep. 30, 2018USD ($)	Oct. 15, 2018USD ($)	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Warrants exercised (shares) | shares					7,000,000
Shares issued upon exercise of warrants (shares) | shares					200,000
Warrants expired unexercised (shares) | shares					5,400,000
Warrants outstanding (shares) | shares					7,900,000		7,900,000
Proceeds from credit facility							$ 200,000,000	$ 0
Amount repaid under credit facility during the period							$ 200,000,000	$ 0
Conversion notices received, amount									$ 273,000,000
Warrant transaction (shares) | shares				16,000,000
Adjustment to number of shares of common stock covered by note hedges and warrant transactions (shares) | shares					20,000,000
Warrant strike price (in USD per share) | $ / shares					$ 93.92		$ 93.92
Shares of common stock covered by warrant transactions (shares) | shares							11,900,000
Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Stated interest rate percentage					0.50%		0.50%			0.50%
Convertible debt										$ 1,440,000,000
Debt repaid	$ 1,160,000,000
Shares issued upon conversion of debt (shares) | shares	4.9
Unsecured Debt [Member] | 2027 Notes [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 750,000,000			$ 750,000,000		$ 750,000,000
Stated interest rate percentage		4.50%
Proceeds from issuance of 2027 Notes, net of issuance costs		$ 741,000,000
Line of Credit [Member]
Debt Instrument [Line Items]
Debt instrument, term			5 years
Credit facility, maximum borrowing capacity			$ 250,000,000
Additional borrowing capacity			$ 250,000,000
Proceeds from credit facility					200,000,000
Amount repaid under credit facility during the period					200,000,000
Amount outstanding					$ 0		$ 0
Consolidated leverage ratio			3.5
Consolidated interest coverage ratio			3
Prior to September 1, 2017 [Member] | Unsecured Debt [Member] | 2027 Notes [Member]
Debt Instrument [Line Items]
Redemption price as percent of aggregate principle amount (percent)		100.00%
Upon Change of Control Prior to Maturity [Member] | Unsecured Debt [Member] | 2027 Notes [Member]
Debt Instrument [Line Items]
Redemption price as percent of aggregate principle amount (percent)		101.00%
Letter of Credit [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity			$ 25,000,000
Swing Line Loans [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity			$ 10,000,000
London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Basis spread on LIBOR (percent)							1.10%
Minimum [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Quarterly facility fee (percent)							0.125%
Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Basis spread on LIBOR (percent)							1.00%
Maximum [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Quarterly facility fee (percent)							0.20%
Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Basis spread on LIBOR (percent)							1.30%
Common Stock [Member]
Debt Instrument [Line Items]
Shares issued upon exercise of warrants (shares) | shares					202,000		202,000
Shares issued upon conversion of debt (shares) | shares						1,300,000	4,950,000

Debt - Schedule of Interest Exp

Debt - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Disclosure [Abstract]
Contractual interest expense	$ 8,438	$ 9,721	$ 26,945	$ 30,283
Amortization of debt issuance costs	182	1,199	1,488	3,578
Amortization of debt discount	41	8,836	8,232	26,312
Debt Instrument, Interest Expense, Total	$ 8,661	$ 19,756	$ 36,665	$ 60,173

Derivative Financial Instrume_3

Derivative Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash flow hedge instrument term, maximum	12 months
Cumulative unrealized gain (loss) on cash flow derivative instruments in accumulated other comprehensive loss	$ (1.6)	$ (1)

Derivative Financial Instrume_4

Derivative Financial Instruments (Schedule Of The Fair Values Of Derivative Instruments) (Details) - Cash Flow Hedging [Member] - Foreign Exchange Contract [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Asset Derivatives
Asset derivatives	$ 362	$ 708
Designated as Hedging Instrument [Member] | Accrued Expenses and Other Current Liabilities [Member]
Liability Derivatives
Liability derivatives	2,102	1,811
Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Asset Derivatives
Asset derivatives	180	56
Not Designated as Hedging Instrument [Member] | Accrued Expenses and Other Current Liabilities [Member]
Liability Derivatives
Liability derivatives	$ 218	$ 732

Derivative Financial Instrume_5

Derivative Financial Instruments (Schedule Of Effect Of Derivative Instruments On Financial Performance) (Details) - Foreign Exchange Contract [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Not Designated as Hedging Instrument [Member] | Other (Expense) Income, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain Recognized in Income on Derivative	$ 4,108	$ 4,452	$ 2,128	$ 8,054
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Loss Recognized in Other Comprehensive (Loss) Income	(1,936)	(451)	(610)	(5,398)
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Operating Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss	$ 162	$ (1,185)	$ (829)	$ 1,031

Derivative Financial Instrume_6

Derivative Financial Instruments (Schedule Of Net Notional Foreign Currency Forward Contracts Outstanding) (Details) - Sep. 30, 2019 € in Thousands, ₩ in Thousands, ₨ in Thousands, ¥ in Thousands, ¥ in Thousands, £ in Thousands, kr in Thousands, kr in Thousands, SFr in Thousands, R$ in Thousands, Kč in Thousands, $ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands

GBP (£)

KRW (₩)

SEK (kr)

DKK (kr)

INR (₨)

JPY (¥)

CHF (SFr)

AUD ($)

CZK (Kč)

HKD ($)

BRL (R$)

EUR (€)

SGD ($)

CAD ($)

CNY (¥)

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Net notional foreign currency forward contracts outstanding

£ 1,800

₩ 609,000

kr 7,600

kr 9,300

₨ 599,000

¥ 78,001

SFr 15,418

$ 20,300

Kč 78,000

$ 33,700

R$ 1900

€ 5,564

$ 13,400

$ 2,050

¥ 59,880

Comprehensive Income (Changes i

Comprehensive Income (Changes in Accumulated Other Comprehensive Loss by Component) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			$ (8,154)
Other comprehensive income (loss) before reclassifications			1,420
Amounts reclassified from accumulated other comprehensive loss			252
Other comprehensive (loss) income	$ (1,872)	$ 427	1,672	$ (7,485)
Balance at September 30, 2019	(6,482)		(6,482)
Foreign Currency [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			(2,946)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from accumulated other comprehensive loss			0
Other comprehensive (loss) income			0
Balance at September 30, 2019	(2,946)		(2,946)
Unrealized Loss on Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			(2,440)
Other comprehensive income (loss) before reclassifications			2,859
Amounts reclassified from accumulated other comprehensive loss			(577)
Other comprehensive (loss) income			2,282
Balance at September 30, 2019	(158)		(158)
Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			(985)
Other comprehensive income (loss) before reclassifications			(1,439)
Amounts reclassified from accumulated other comprehensive loss			829
Other comprehensive (loss) income			(610)
Balance at September 30, 2019	(1,595)		(1,595)
Other Comprehensive Loss on Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2018			(1,783)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from accumulated other comprehensive loss			0
Other comprehensive (loss) income			0
Balance at September 30, 2019	$ (1,783)		$ (1,783)

Comprehensive Income (Reclassif

Comprehensive Income (Reclassifications out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net		$ (3,456)	$ (3,702)	$ (3,735)	$ 1,847
Operating expenses		495,152	463,780	1,505,114	1,375,592
Net income		(270,857)	$ (158,857)	(474,700)	$ (409,949)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income		(155)		252
Unrealized Net (Loss) Gains on Available-for-sale Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net		7		(577)
Unrealized Net Gains (Losses) on Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating expenses	[1]	$ (162)		$ 829
[1]	Operating expenses amounts allocated to Research and development, Sales, marketing and services, and General and administrative are not individually significant.

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Effective tax rate	(150.50%)	0.40%	(42.30%)	7.20%
Income tax benefit due to remeasurement of Swiss deferred tax assets	$ 157.7		$ 157.7
Tax benefit attributable to the 2015 U.S. federal income tax return statute of limitations closing	17.3		17.3
Net unrecognized tax benefit	84.3		84.3		$ 89.9
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	57.3		57.3
Income tax interest and penalties accrued	4		4
Net deferred tax assets	$ 300.3		$ 300.3

Treasury Stock (Details)

Treasury Stock (Details) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended
	Apr. 30, 2018	Feb. 28, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Oct. 31, 2019	Oct. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount								$ 750,000,000
Document Period End Date					Sep. 30, 2019
Available to repurchase common stock			$ 414,000,000		$ 414,000,000
Amount expended on share repurchases in open market transactions			$ 103,905,000	$ 116,175,000	$ 353,904,000	$ 881,154,000
Number of shares withheld to satisfy minimum tax withholding obligations			44,829	32,813	742,946	570,589
Payment for tax withholding related to vested stock units			$ 4,200,000	$ 3,700,000	$ 74,800,000	$ 53,600,000
Open Market Purchases [Member]
Equity, Class of Treasury Stock [Line Items]
Amount expended on share repurchases in open market transactions			$ 103,900,000	$ 116,200,000	$ 353,900,000	$ 131,200,000
Stock repurchases net (shares)			1,130,100	1,000,000	3,640,982	1,200,000
Average per share price on share repurchases in open market transactions (in dollars per share)			$ 91.94	$ 111.11	$ 97.20	$ 110.60
ASR Counterparty [Member]
Equity, Class of Treasury Stock [Line Items]
Amount expended on share repurchases in open market transactions		$ 750,000,000
Stock repurchases net (shares)	1,600,000	6,500,000
Subsequent Event [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount							$ 600,000,000

Commitments and Contingencies (

Commitments and Contingencies (Details)	9 Months Ended
	Sep. 30, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Self-insured retention	$ 500,000
Total insurance limit	200,000,000
Purchase commitment in fiscal year 2020	$ 25,000,000

Restructuring Restructuring (De

Restructuring Restructuring (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Employee severance and related costs	$ 6,213	$ 22	$ 13,356	$ 2,341
Consolidation of leased facilities	2,666	(508)	2,666	10,797
Total Restructuring charges	$ 8,879	$ (486)	$ 16,022	$ 13,138

Restructuring (Narrative) (Deta

Restructuring (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Employee severance and related costs	$ 6,213	$ 22	$ 13,356	$ 2,341
Consolidation of leased facilities	2,666	$ (508)	2,666	$ 10,797
Outstanding restructuring accruals	$ 5,696		$ 5,696		$ 45,095

Restructuring (Activity in Rest

Restructuring (Activity in Restructuring Accruals) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Balance at January 1, 2019			$ 45,095
Adjustment for ASC 842			(42,248)		$ 42,200
Employee severance and related costs	$ 6,213	$ 22	13,356	$ 2,341
Payments			(10,507)
Balance at September 30, 2019	$ 5,696		$ 5,696		$ 45,095

Statement of Changes in Equit_2

Statement of Changes in Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 20, 2019	Jun. 21, 2019	Mar. 22, 2019	Jan. 01, 2019	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Cash dividend paid (in dollars per share)	$ 0.35	$ 0.35	$ 0.35
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				$ 551,519	$ 508,022	$ 753,220	$ 636,176	$ 551,519	$ 992,461
Shares issued under stock-based compensation plans					0		50	0	164
Stock-based compensation expense					68,969		52,739	202,523	145,920
Temporary equity reclassification							8,796	8,110	(19,286)
Common stock issued under employee stock purchase plan					20,455		16,004	39,471	33,462
Stock repurchases, net					$ (103,905)		$ (116,175)	$ (353,904)	$ (881,154)
Restricted shares turned in for tax withholding (in shares)					(44,829)		(32,813)	(742,946)	(570,589)
Restricted shares turned in for tax withholding					$ (4,242)		$ (3,654)	$ (74,794)	$ (53,589)
Other comprehensive income, net of tax					(1,872)		427	1,672	(7,485)
Cash dividends declared					$ (45,373)			(137,224)
Settlement of convertible notes and hedges								0
Settlement of warrants (in shares)					200,000
Cumulative-effect adjustment from adoption of accounting standards				$ 800				838	132,778
Net income					$ 270,857		158,857	474,700	409,949
Ending balance					$ 712,911	$ 551,519	$ 753,220	$ 712,911	$ 753,220
Beginning balance, treasury shares (in shares)				(178,327,000)				(178,327,000)
Ending balance, treasury shares (in shares)					(187,661,000)	(178,327,000)		(187,661,000)
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				309,761,000	316,969,000	307,981,000	307,662,000	309,761,000	305,751,000
Shares issued under stock compensation plans (shares)					123,000		110,000	2,167,000	1,769,000
Common stock issued under employee stock purchase plan (shares)					255,000		209,000	471,000	461,000
Ending balance (in shares)					317,549,000	309,761,000	307,981,000	317,549,000	307,981,000
Beginning balance				$ 310	$ 317	$ 308	$ 308	$ 310	$ 306
Shares issued under stock-based compensation plans								$ 2	2
Common stock issued under employee stock purchase plan					$ 1
Shares issued upon conversion of debt (shares)						(1,300,000)		(4,950,000)
Settlement of convertible notes and hedges								$ (5)
Settlement of warrants (in shares)					202,000			202,000
Other								(2,000)
Ending balance					$ 318	$ 310	308	$ 318	308
Additional Paid-in Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				5,404,500	6,078,960	5,193,928	5,116,339	5,404,500	4,883,670
Shares issued under stock-based compensation plans							50	(2)	162
Stock-based compensation expense					68,969		52,739	202,523	145,920
Temporary equity reclassification							8,796	8,110	(19,286)
Common stock issued under employee stock purchase plan					20,454		16,004	39,470	33,462
Accelerated stock repurchase program									150,000
Settlement of convertible notes and hedges								(509,519)
Other					2,194			6,457
Ending balance					6,170,577	5,404,500	5,193,928	6,170,577	5,193,928
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				4,169,019	4,277,586	4,052,211	3,893,354	4,169,019	3,509,484
Cash dividends declared					(45,373)			(137,224)
Cumulative-effect adjustment from adoption of accounting standards								838	132,778
Other					(2,194)			(6,457)
Net income					270,857		158,857	474,700	409,949
Ending balance					4,500,876	4,169,019	4,052,211	4,500,876	4,052,211
Accumulated Other Comprehensive Loss [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				(8,154)	(4,610)	(18,291)	(18,718)	(8,154)	(10,806)
Other comprehensive income, net of tax					(1,872)		427	1,672	(7,485)
Ending balance					(6,482)	(8,154)	(18,291)	(6,482)	(18,291)
Common Stock in Treasury [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				$ (9,014,156)	$ (9,844,231)	(8,474,936)	$ (8,355,107)	$ (9,014,156)	$ (7,390,193)
Stock repurchases net (shares)					(1,130,000)		(1,046,000)	(3,641,000)	(10,708,000)
Stock repurchases, net					$ (103,905)		$ (116,175)	$ (353,904)	$ (1,031,154)
Restricted shares turned in for tax withholding (in shares)					(45,000)		(32,000)	(743,000)	(570,000)
Restricted shares turned in for tax withholding					$ (4,242)		$ (3,654)	$ (74,794)	$ (53,589)
Shares issued upon conversion of debt (shares)								(4,950,000)
Settlement of convertible notes and hedges								$ (509,524)
Ending balance					$ (9,952,378)	$ (9,014,156)	$ (8,474,936)	$ (9,952,378)	$ (8,474,936)
Beginning balance, treasury shares (in shares)				(178,327,000)	(186,486,000)	(173,322,000)	(172,244,000)	(178,327,000)	(162,044,000)
Ending balance, treasury shares (in shares)					(187,661,000)	(178,327,000)	(173,322,000)	(187,661,000)	(173,322,000)

Statement of Changes in Equit_3

Statement of Changes in Equity - Subsequent Event (Details)	Oct. 24, 2019$ / shares
Subsequent Event [Member]
Quarterly dividend approved (per share)	$ 0.35

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 12,599	$ 37,376
Variable lease cost	2,748	7,566
Sublease income	(236)	(667)
Net lease cost	$ 15,111	$ 44,275

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 41,199
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 52,179

Leases - Lease Term and Discoun

Leases - Lease Term and Discount Rate (Details)	Sep. 30, 2019
Weighted-average remaining lease term (years)
Operating leases	6 years 2 months 12 days
Weighted-average discount rate
Operating leases (percent)	5.00%

Leases - Maturity of Lease Liab

Leases - Maturity of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Operating Leases
2019 (remaining three months)	$ 11,907
2020	61,054
2021	52,483
2022	44,406
2023	40,931
After 2023	102,716
Total lease payments	313,497
Less: imputed interest	(45,136)
Present value of lease liabilities	$ 268,361	$ 256,400

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leases
Operating lease right-of-use assets	$ 218,625	$ 194,500	$ 0
Total operating lease liabilities	268,361	$ 256,400
Accrued Expenses and Other Current Liabilities [Member]
Operating Leases
Total operating lease liabilities	47,329
Operating Lease Liabilities [Member]
Operating Leases
Total operating lease liabilities	$ 221,032