Citrix Systems (CTXS) 10-K 18 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 12, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	ctxs
Entity Registrant Name	CITRIX SYSTEMS INC
Entity Central Index Key	877,890
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		153,979,766
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 10,767,687,991

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents		$ 368,518	$ 260,149
Short-term investments, available-for-sale		502,852	529,260
Accounts receivable, net of allowances of $7,719 and $5,976 at December 31, 2015 and 2014, respectively		669,276	674,401
Inventories, net		10,521	12,617
Prepaid expenses and other current assets		132,784	166,005
Current portion of deferred tax assets, net	[1]	0	45,892
Total current assets		1,683,951	1,688,324
Long-term investments, available-for-sale		891,964	1,073,110
Property and equipment, net		373,817	367,779
Goodwill		1,962,722	1,796,851
Other intangible assets, net		283,418	390,717
Long-term portion of deferred tax assets, net		215,196	128,198
Other assets		70,370	67,028
Total assets		5,481,438	5,512,007
Current liabilities:
Accounts payable		95,396	79,884
Accrued expenses and other current liabilities		317,468	298,079
Income taxes payable		18,351	12,053
Current portion of deferred revenues		1,249,754	1,200,093
Total current liabilities		1,680,969	1,590,109
Long-term portion of deferred revenues		414,314	357,771
Convertible notes		1,324,992	1,292,953
Other liabilities		$ 87,717	$ 97,529
Commitments and contingencies
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; 299,113 and 294,674 shares issued and outstanding at December 31, 2015 and 2014, respectively		299	295
Additional paid-in capital		4,566,919	4,292,706
Retained earnings		3,474,625	3,155,264
Accumulated other comprehensive loss		(28,527)	(36,790)
Stockholders' equity before treasury stock		8,013,316	7,411,475
Less - common stock in treasury, at cost (145,296 and 133,898 shares at December 31, 2015 and 2014, respectively)		(6,039,870)	(5,237,830)
Total stockholders' equity		1,973,446	2,173,645
Total liabilities and stockholders' equity		$ 5,481,438	$ 5,512,007
[1]	During the year ended December 31, 2015, the Company elected to early adopt an accounting standard update on income taxes on a prospective basis. The new authoritative guidance requires deferred tax liabilities and assets along with any related valuation allowance to be classified as noncurrent on the consolidated balance sheet. The December 31, 2014 consolidated balance sheet was not retrospectively adjusted.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$ 7,719	$ 5,976
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	299,113,000	294,674,000
Common stock, shares outstanding	299,113,000	294,674,000
Treasury Stock, Shares	145,296,000	133,898,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Product and licenses		$ 875,807	$ 899,736	$ 891,630
Software as a service		731,292	651,562	582,872
License updates and maintenance		1,521,007	1,416,017	1,305,053
Professional services		147,488	175,541	138,879
Total net revenues		3,275,594	3,142,856	2,918,434
Cost of net revenues:
Cost of product and license revenues		118,265	124,110	114,932
Cost of services and maintenance revenues		364,916	349,683	289,990
Amortization and impairment of product related intangible assets		131,183	146,426	97,873
Total cost of net revenues		614,364	620,219	502,795
Gross margin		2,661,230	2,522,637	2,415,639
Operating expenses:
Research and development		563,975	553,817	516,338
Sales, marketing and services		1,195,362	1,280,265	1,216,680
General and administrative		342,665	319,922	260,236
Amortization and impairment of other intangible assets		108,732	45,898	41,668
Restructuring	[1]	100,411	20,424	0
Total operating expenses		2,311,145	2,220,326	2,034,922
Income from operations		350,085	302,311	380,717
Interest income		11,675	9,421	8,194
Interest expense		44,153	28,332	128
Other expense, net		(5,730)	(7,694)	(893)
Income before income taxes		311,877	275,706	387,890
Income tax (benefit) expense		(7,484)	23,983	48,367
Net income		$ 319,361	$ 251,723	$ 339,523
Earnings per share:
Basic (USD per share)		$ 2.01	$ 1.48	$ 1.82
Diluted (USD per share)		$ 1.99	$ 1.47	$ 1.80
Weighted average shares outstanding:
Basic (in shares)		158,874	169,879	186,672
Diluted (in shares)		160,362	171,270	188,245
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 319,361	$ 251,723	$ 339,523
Other comprehensive income (loss):
Change in foreign currency translation adjustment	0	(21,804)	8,482
Available for sale securities:
Change in net unrealized losses	(2,080)	(911)	(985)
Less: reclassification adjustment for net losses (gains) included in net income	170	(1,317)	(203)
Net change (net of tax effect)	(1,910)	(2,228)	(1,188)
Gain (loss) on pension liability	4,083	(6,512)	2,500
Cash flow hedges:
Change in unrealized losses	(6,937)	(9,074)	(67)
Less: reclassification adjustment for net losses (gains) included in net income	13,027	(2,123)	2,929
Net change (net of tax effect)	6,090	(11,197)	2,862
Other comprehensive income (loss)	8,263	(41,741)	12,656
Comprehensive income	$ 327,624	$ 209,982	$ 352,179

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid In Capital	Retained Earnings	Accumulated Other Comprehensive (loss) income	Common Stock in Treasury
Beginning balance (in shares) at Dec. 31, 2012		287,123,000
Beginning balance at Dec. 31, 2012	$ 3,121,777	$ 287	$ 3,691,111	$ 2,564,018	$ (7,705)	$ (3,125,934)
Beginning balance, treasury shares (in shares) at Dec. 31, 2012						(100,781,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued under stock-based compensation plans	73,658	$ 3	73,655	0	0	$ 0
Shares issued under stock-based compensation plans (in shares)		3,545,000				0
Stock-based compensation expense	179,098	$ 0	179,098	0	0	$ 0
Common stock issued under employee stock purchase plan	30,142	$ 1	30,141	0	0	$ 0
Common stock issued under employee stock purchase plan (in shares)		410,000				0
Tax deficiency from employer stock plans, net	(620)	$ 0	(620)	0	0	$ 0
Stock repurchases, net	(406,326)	$ 0	0	0	0	$ (406,326)
Stock repurchases, net (in shares)		0				(6,564,000)
Restricted shares turned in for tax withholding	$ (31,013)	$ 0	0	0	0	$ (31,013)
Restricted shares turned in for tax withholding (in shares)	(444,657)	0				(444,000)
Other	$ 912	$ 0	912	0	0	$ 0
Other comprehensive income (loss), net of tax	12,656	0	0	0	12,656	0
Net income	339,523	$ 0	0	339,523	0	0
Ending balance (in shares) at Dec. 31, 2013		291,078,000
Ending balance at Dec. 31, 2013	3,319,807	$ 291	3,974,297	2,903,541	4,951	$ (3,563,273)
Ending balance, treasury shares (in shares) at Dec. 31, 2013						(107,789,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued under stock-based compensation plans	46,621	$ 3	46,618	0	0	$ 0
Shares issued under stock-based compensation plans (in shares)		3,031,000				0
Stock-based compensation expense	164,040	$ 0	164,040	0	0	$ 0
Common stock issued under employee stock purchase plan	33,909	$ 1	33,908	0	0	$ 0
Common stock issued under employee stock purchase plan (in shares)		565,000				0
Tax deficiency from employer stock plans, net	(14,679)	$ 0	(14,679)	0	0	$ 0
Stock repurchases, net	(1,640,885)	$ 0	0	0	0	$ (1,640,885)
Stock repurchases, net (in shares)		0				(25,549,000)
Restricted shares turned in for tax withholding	$ (33,672)	$ 0	0	0	0	$ (33,672)
Restricted shares turned in for tax withholding (in shares)	(560,239)	0				(560,000)
Other comprehensive income (loss), net of tax	$ (41,741)	$ 0	0	0	(41,741)	$ 0
Convertible note tax impact	8,166		8,166
Equity component of convertible note issuance	162,869		162,869
Purchase of convertible note hedges	(184,288)		(184,288)
Issuance of warrants	101,775	0	101,775	0	0
Net income	251,723	$ 0	0	251,723	0	0
Ending balance (in shares) at Dec. 31, 2014		294,674,000
Ending balance at Dec. 31, 2014	$ 2,173,645	$ 295	4,292,706	3,155,264	(36,790)	$ (5,237,830)
Ending balance, treasury shares (in shares) at Dec. 31, 2014	(133,898,000)					(133,898,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued under stock-based compensation plans	$ 112,285	$ 3	112,282	0	0	$ 0
Shares issued under stock-based compensation plans (in shares)		3,878,000				0
Stock-based compensation expense	139,816	$ 0	139,816	0	0	$ 0
Common stock issued under employee stock purchase plan	37,229	$ 1	37,228	0	0	$ 0
Common stock issued under employee stock purchase plan (in shares)		561,000				0
Tax deficiency from employer stock plans, net	(15,013)	$ 0	(15,013)	0	0	$ 0
Stock repurchases, net	(755,704)	$ 0	0	0	0	$ (755,704)
Stock repurchases, net (in shares)		0				(10,717,000)
Restricted shares turned in for tax withholding	$ (46,336)	$ 0	0	0	0	$ (46,336)
Restricted shares turned in for tax withholding (in shares)	(679,694)	0				(681,000)
Other	$ (100)	$ 0	(100)	0	0	$ 0
Other comprehensive income (loss), net of tax	8,263	0	0	0	8,263	0
Net income	319,361	$ 0	0	319,361	0	0
Ending balance (in shares) at Dec. 31, 2015		299,113,000
Ending balance at Dec. 31, 2015	$ 1,973,446	$ 299	$ 4,566,919	$ 3,474,625	$ (28,527)	$ (6,039,870)
Ending balance, treasury shares (in shares) at Dec. 31, 2015	(145,296,000)					(145,296,000)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income		$ 319,361	$ 251,723	$ 339,523
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and impairment of intangible assets	[1]	239,915	192,325	139,541
Depreciation and amortization of property and equipment		152,964	137,945	127,959
Amortization of debt discount and transaction costs		36,013	23,293	0
Stock-based compensation expense		147,368	169,287	183,941
Deferred income tax benefit		(89,378)	(36,982)	(51,848)
Excess tax benefit from stock-based compensation		(5,873)	(6,132)	(12,552)
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies		13,416	5,233	5,888
Other non-cash items		8,740	12,419	5,417
Total adjustments to reconcile net income to net cash provided by operating activities		503,165	497,388	398,346
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable		(7,226)	(30,962)	(22,951)
Inventories		703	(1,167)	(5,591)
Prepaid expenses and other current assets		(8,057)	(8,133)	(7,928)
Other assets		(2,550)	1,498	5,076
Income taxes, net		51,994	(79,119)	(7,374)
Accounts payable		10,959	40	3,092
Accrued expenses and other current liabilities		49,586	62,195	23,028
Deferred revenues		107,150	146,123	201,455
Other liabilities		9,463	6,395	1,667
Total changes in operating assets and liabilities, net of the effects of acquisitions		212,022	96,870	190,474
Net cash provided by operating activities		1,034,548	845,981	928,343
Investing Activities
Purchases of available-for-sale investments		(2,182,831)	(2,390,950)	(1,703,976)
Proceeds from sales of available-for-sale investments		1,745,290	1,694,886	766,192
Proceeds from maturities of available-for-sale investments		637,052	406,334	504,314
Proceeds (purchases) from cost method investments, net		6,476	425	5,243
Cash paid for acquisitions, net of cash acquired		(256,907)	(101,059)	(334,881)
Purchases of property and equipment		(160,825)	(165,417)	(162,889)
Cash paid for licensing agreements and product related intangible assets		(11,403)	(13,676)	(12,153)
Other		(1,267)	0	0
Net cash used in investing activities		(224,415)	(569,457)	(938,150)
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plans		112,285	46,618	73,655
Proceeds from issuance of convertible notes, net of issuance costs		0	1,415,717	0
Purchase of convertible note hedges		0	(184,288)	0
Proceeds from issuance of warrants		0	101,775	0
Proceeds from revolving credit facility		95,000	0	0
Repayments on credit facility		(95,000)	0	0
Repayment of acquired debt		(7,569)	(4,065)	(2,061)
Excess tax benefit from stock-based compensation		5,873	6,132	12,552
Stock repurchases, net		(755,704)	(1,640,885)	(406,326)
Cash paid for tax withholding on vested stock awards		(46,336)	(33,672)	(31,013)
Other		0	0	912
Net cash used in financing activities		(691,451)	(292,668)	(352,281)
Effect of exchange rate changes on cash and cash equivalents		(10,313)	(4,447)	(781)
Change in cash and cash equivalents		108,369	(20,591)	(362,869)
Cash and cash equivalents at beginning of period		260,149	280,740	643,609
Cash and cash equivalents at end of period		368,518	260,149	280,740
Supplemental Cash Flow Information
Cash paid for income taxes		45,827	130,502	92,672
Cash paid for interest		$ 8,215	$ 5,027	$ 127
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments

Organization

Organization	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION	ORGANIZATION Citrix Systems, Inc. ("Citrix" or the "Company"), is a Delaware corporation founded on April 17, 1989. Citrix develops and sells products and services that enable the secure and reliable delivery of applications and data over public, private or hybrid clouds or networks, to virtually any type of device. Citrix markets and licenses its products directly to customers, over the Web, and through systems integrators ("SIs"), in addition to indirectly through value-added resellers ("VARs"), value-added distributors ("VADs"), original equipment manufacturers ("OEMs"), and service providers. The Company’s revenues are derived from its Enterprise and Service Provider products, which primarily include its Workspace Services products, Delivery Networking products and related license updates and maintenance and professional services and from its Mobility Apps products, which primarily include Communications Cloud and Workflow Cloud products. Enterprise and Service Provider and Mobility Apps constitute the Company's two reportable segments. As part of the Company's continued transformation, effective January 1, 2016, the Company reorganized a part of its business by creating a new Cloud Services business unit that will include the ShareFile product line. The ShareFile product line is currently included within the Company's Workflow Cloud products under the Mobility Apps segment. The Company is currently evaluating its segment reporting and goodwill reporting units for 2016 as a result of these changes. See Note 11 for more information regarding the Company's segments.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	SIGNIFICANT ACCOUNTING POLICIES Consolidation Policy The 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. All significant transactions and balances between the Company and its subsidiaries have been eliminated in consolidation. Cash and Cash Equivalents Cash and cash equivalents at December 31, 2015 and 2014 include marketable securities, which are primarily money market funds, commercial paper, agency, and government securities, municipal securities and corporate securities with initial or remaining contractual maturities when purchased of three months or less. Investments Short-term and long-term investments at December 31, 2015 and 2014 primarily consist of agency securities, corporate securities, municipal securities and government securities. Investments classified as available-for-sale 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 4 for investment information. Accounts Receivable The Company’s accounts receivable are attributable primarily to VARs, VADs and end customers. Collateral is generally not required. The Company also maintains allowances for doubtful accounts for estimated losses resulting from the inability of the Company’s customers to make payments which includes both general and specific reserves. The Company periodically reviews these estimated allowances by conducting an analysis of the customer's payment history and creditworthiness, the age of the trade receivable balances and current economic conditions that may affect a customer’s ability to make payments. Based on this review, the Company specifically reserves for those accounts deemed uncollectible. When receivables are determined to be uncollectible, principal amounts of such receivables outstanding are deducted from the allowance. The allowance for doubtful accounts was $6.3 million and $3.8 million as of December 31, 2015 and 2014 , respectively. If the financial condition of a significant distributor or customer were to deteriorate, the Company’s operating results could be adversely affected. As of December 31, 2015 , there was no individual distributor that accounted for over 10% of gross accounts receivable. As of December 31, 2014 , two distributors, the Arrow Group and Ingram Micro, accounted for 11% and 10% of gross accounts receivable, respectively. Inventory Inventories are stated at the lower of cost or market on a standard cost basis, which approximates actual cost. The Company’s inventories primarily consist of finished goods as of December 31, 2015 and 2014 . Property and Equipment Property and equipment is stated at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which is generally three years for computer equipment and software, the lesser of the lease term or ten years for leasehold improvements, which is the estimated useful life, seven years for office equipment and furniture and the Company’s enterprise resource planning system and 40 years for buildings. During 2015 and 2014 , the Company retired $25.8 million and $11.4 million , respectively, in property and equipment that were no longer in use. At the time of retirement, the remaining net book value of the assets retired was not material and no material asset retirement obligations were associated with them. Property and equipment consist of the following: December 31, 2015 2014 (In thousands) Buildings $ 85,092 $ 85,092 Computer equipment 271,461 237,709 Software 487,191 392,009 Equipment and furniture 123,649 117,555 Leasehold improvements 217,200 211,625 1,184,593 1,043,990 Less accumulated depreciation and amortization (852,460 ) (722,691 ) Assets under construction 14,097 18,893 Land 27,587 27,587 Total $ 373,817 $ 367,779 Long-Lived Assets The Company reviews for impairment of long-lived assets and certain identifiable intangible assets to be held and used whenever events or changes in circumstances indicate that the carrying amount of such assets may not be fully recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. Measurement of an impairment loss is based on the fair value of the asset compared to its carrying value. Long-lived assets and certain identifiable intangible assets to be disposed of are reported at the lower of carrying amount or fair value less costs to sell. For the years ended December 31, 2015 and 2014 , the Company identified certain intangible assets that were impaired within our Enterprise and Service Provider segment and recorded non-cash impairment charges of $123.0 million and $59.3 million , respectively. These non-recurring fair value measurements were categorized as Level 3, as significant unobservable inputs were used in the valuation analysis. The impairment charges are included in Amortization and impairment of product related intangible assets and Amortization and impairment of other intangible assets in the accompanying consolidated statements of income. See Note 3 for more information regarding the Company's acquisitions and Note 5 for more information regarding fair value measurements. 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. There was no impairment of goodwill or indefinite lived intangible assets as a result of the annual impairment tests analyses completed during the fourth quarters of 2015 and 2014 , respectively. The authoritative guidance provides entities with an option to perform a qualitative assessment to determine whether further quantitative impairment testing is necessary. The Company performed the qualitative assessment when it performed its goodwill impairment test in the fourth quarter of 2015 . As a result of the qualitative analysis, no further quantitative impairment test was deemed necessary. In-process R&D acquired in connection with the Company's acquisitions was not significant. See Note 3 for more information regarding the Company's acquisitions and Note 11 for more information regarding the Company's segments. The following table presents the change in goodwill allocated to the Company’s reportable segments during 2015 and 2014 (in thousands): Balance at January 1, 2015 Additions Other Balance at December 31, 2015 Balance at January 1, 2014 Additions Other Balance at December 31, 2014 Enterprise and Service Provider $ 1,434,369 $ 61,641 $ (740 ) (2) $ 1,495,270 $ 1,402,156 $ 30,317 $ 1,896 (4) $ 1,434,369 Mobility Apps 362,482 104,970 — 467,452 366,793 10,694 (15,005 ) (3) 362,482 Consolidated $ 1,796,851 $ 166,611 (1) $ (740 ) $ 1,962,722 $ 1,768,949 $ 41,011 (1) $ (13,109 ) $ 1,796,851 (1) Amount primarily relates to 2015 acquisitions. See Note 3 for more information regarding the Company’s acquisitions. (2) Amount primarily relates to adjustments to purchase price allocations for certain 2014 Acquisitions. (3) Amount primarily relates to foreign currency translation. Refer to Foreign Currency discussion below for additional information. (4) Amount primarily relates to adjustments to purchase price allocations for certain 2013 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 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): December 31, 2015 Gross Carrying Amount Accumulated Amortization Weighted-Average Life (Years) Product related intangible assets $ 589,847 $ 476,141 5.67 Other 447,816 278,104 6.48 Total $ 1,037,663 $ 754,245 6.27 December 31, 2014 Gross Carrying Amount Accumulated Amortization Weighted-Average Life (Years) Product related intangible assets $ 618,336 $ 454,830 5.58 Other 492,960 265,749 7.58 Total $ 1,111,296 $ 720,579 6.47 Amortization and impairment of product related intangible assets, which consists primarily of product-related technologies and patents, was $ 131.2 million and $ 146.4 million for the year ended December 31, 2015 and 2014 , respectively, and is classified as a component of Cost of net revenues in the accompanying consolidated statements of income. Amortization and impairment of other intangible assets, which consist primarily of customer relationships, trade names and covenants not to compete was $ 108.8 million and $ 45.9 million for the year ended December 31, 2015 and 2014 , respectively, and is classified as a component of Operating expenses in the accompanying consolidated statements of income. The Company monitors its intangible assets for indicators of impairment. If the Company determines that an impairment has occurred, it will write-down the intangible asset to its fair value. For certain intangible assets where the unamortized balances exceed 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 year ended December 31, 2015 , 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 identified certain definite-lived intangible assets that were impaired within our Enterprise and Service Provider business unit, primarily customer relationships and product technologies from the acquisition of ByteMobile and Sanbolic, and recorded non-cash impairment charges of $123.0 million to write down the intangible assets to their estimated fair value of $26.8 million . Of the impairment charge, $67.1 million is included in Amortization and impairment of other intangible assets and $55.9 million is included in Amortization and impairment of product related intangible assets in the accompanying consolidated statements of income. This non-recurring fair value measurement was 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 retention rates, 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 December 31, 2015 is as follows (in thousands): Year ending December 31, 2016 $ 81,687 2017 60,013 2018 52,003 2019 36,047 2020 21,792 Thereafter 31,876 Total $ 283,418 Software Development Costs The authoritative guidance requires certain internal software development costs related to software to be sold to be capitalized upon the establishment of technological feasibility. The Company's software development costs incurred subsequent to achieving technological feasibility have not been significant and substantially all software development costs have been expensed as incurred. Internal Use Software In accordance with the authoritative guidance, the Company capitalizes external direct costs of materials and services and internal costs such as payroll and benefits of those employees directly associated with the development of new functionality in internal use software and software developed related to its Mobility Apps products. The amount of costs capitalized in 2015 and 2014 relating to internal use software was $93.9 million and $79.1 million , respectively. These costs are being amortized over the estimated useful life of the software, which is generally three to seven years, and are included in property and equipment in the accompanying consolidated balance sheets. The total amounts charged to expense relating to internal use software was approximately $81.8 million , $66.8 million and $58.6 million , during the years ended December 31, 2015 , 2014 and 2013 , respectively. Revenue Recognition Net revenues include the following categories: Product and licenses, SaaS, License updates and maintenance and Professional services. Product and licenses revenues primarily represent fees related to the licensing of the Company’s software and hardware appliances. These revenues are reflected net of sales allowances, cooperative advertising agreements, partner incentive programs and provisions for returns. SaaS revenues consist primarily of fees related to online service agreements, which are recognized ratably over the contract term, which is typically 12 months. In addition, SaaS revenues may also include set-up fees, which are recognized ratably over the contract term or the expected customer life, whichever is longer. License updates and maintenance revenues consist of fees related to the Subscription Advantage program and maintenance fees, which include technical support and hardware and software maintenance. Subscription Advantage is a renewable program that provides subscribers with immediate access to software upgrades, enhancements and maintenance releases when and if they become available during the term of the contract. Subscription Advantage and maintenance fees are recognized ratably over the term of the contract, which is typically 12 to 24 months. The Company capitalizes certain third-party commissions related to Subscription Advantage, maintenance and support renewals. The capitalized commissions are amortized to Sales, marketing and services expense at the time the related deferred revenue is recognized as revenue. Hardware and software maintenance and support contracts are typically sold separately. Hardware maintenance includes technical support, the latest software upgrades and replacement of malfunctioning appliances. Dedicated account management is available as an add-on to the program for a higher level of service. Software maintenance includes unlimited technical support, immediate access to software upgrades, enhancements and maintenance releases when and if they become available during the term of the contract. Professional services revenues are comprised of fees from consulting services related to the implementation of the Company’s products and fees from product training and certification, which are recognized as the services are provided. The Company recognizes revenue when it is earned and when all of the following criteria are met: persuasive evidence of the arrangement exists; delivery has occurred or the service has been provided and the Company has no remaining obligations; the fee is fixed or determinable; and collectability is probable. The Company defines these four criteria as follows: • Persuasive evidence of the arrangement exists. Evidence of an arrangement generally consists of a purchase order issued pursuant to the terms and conditions of a distributor, reseller or end user agreement. For SaaS, the Company generally requires the customer or the reseller to electronically accept the terms of an online services agreement or execute a contract. • Delivery has occurred and the Company has no remaining obligations. The Company considers delivery of licenses under electronic licensing agreements to have occurred when the related products are shipped and the end-user has been electronically provided the software activation keys that allow the end-user to take immediate possession of the product. For hardware appliance sales, the Company’s standard delivery method is free-on-board shipping point. Consequently, it considers delivery of appliances to have occurred when they are shipped pursuant to an agreement and purchase order. For SaaS, delivery occurs upon providing the users with their login id and password. For product training and consulting services, the Company fulfills its obligation when the services are performed. For license updates and maintenance, the Company assumes that its obligation is satisfied ratably over the respective terms of the agreements, which are typically 12 to 24 months. For SaaS, the Company assumes that its obligation is satisfied ratably over the respective terms of the agreements, which are typically 12 months. • The fee is fixed or determinable. In the normal course of business, the Company does not provide customers the right to a refund of any portion of their license fees or extended payment terms. The fees are considered fixed or determinable upon establishment of an arrangement that contains the final terms of the sale including description, quantity and price of each product or service purchased. For SaaS, the fee is considered fixed or determinable if it is not subject to refund or adjustment. • Collectability is probable. The Company assesses collectability based primarily on the creditworthiness of the customer. Management’s judgment is required in assessing the probability of collection, which is generally based on an evaluation of customer specific information, historical experience and economic market conditions. If the Company determines from the outset of an arrangement that collectability is not probable, revenue recognition is deferred until customer payment is received and the other parameters of revenue recognition described above have been achieved. The majority of the Company’s product and license revenue consists of revenue from the sale of software products. Software sales generally include a perpetual license to the Company’s software and is subject to the industry specific software revenue recognition guidance. In accordance with this guidance, the Company allocates revenue to license updates related to its stand-alone software and any other undelivered elements of the arrangement based on vendor specific objective evidence (“VSOE”) of fair value of each element and such amounts are deferred until the applicable delivery criteria and other revenue recognition criteria described above have been met. The balance of the revenues, net of any discounts inherent in the arrangement, is recognized at the outset of the arrangement using the residual method as the product licenses are delivered. If management cannot objectively determine the fair value of each undelivered element based on VSOE of fair value, revenue recognition is deferred until all elements are delivered, all services have been performed, or until fair value can be objectively determined. For hardware appliance and software transactions, the arrangement consideration is allocated to stand-alone software deliverables as a group and the non-software deliverables based on the relative selling prices using the selling price hierarchy in the revenue recognition guidance. The selling price hierarchy for a deliverable is based on its VSOE if available, third-party evidence of selling price ("TPE") if VSOE is not available, or estimated selling price ("ESP") if neither VSOE nor TPE is available. The Company then recognizes revenue on each deliverable in accordance with its policies for product and service revenue recognition. VSOE of selling price is based on the price charged when the element is sold separately. In determining VSOE, the Company requires that a substantial majority of the selling prices fall within a reasonable range based on historical discounting trends for specific products and services. TPE of selling price is established by evaluating competitor products or services in stand-alone sales to similarly situated customers. However, as the Company’s products contain a significant element of proprietary technology and its solutions offer substantially different features and functionality, the comparable pricing of products with similar functionality typically cannot be obtained. Additionally, as the Company is unable to reliably determine what competitors products’ selling prices are on a stand-alone basis, the Company is not typically able to determine TPE. The estimate of selling price is established considering multiple factors including, but not limited to, pricing practices in different geographies and through different sales channels and competitor pricing strategies. Our Citrix Service Provider ("CSP") program provides subscription-based services in which the CSP partners host software services to their end users. The fees from the CSP program are recognized based on usage and as the CSP services are provided to their end users. For the Company’s non-software transactions, it allocates the arrangement consideration based on the relative selling price of the deliverables. For the Company’s hardware appliances, it uses ESP as its selling price. For the Company’s support and services, it generally uses VSOE as its selling price. When the Company is unable to establish selling price using VSOE for its support and services, the Company uses ESP in its allocation of arrangement consideration. The Company’s Mobility Apps products are considered hosted service arrangements per the authoritative guidance, or SaaS. Generally, the Company’s Mobility Apps products are sold separately and not bundled with the Enterprise and Service Provider business unit’s products and services. In the normal course of business, the Company is not obligated to accept product returns from its distributors under any conditions, unless the product item is defective in manufacture. The Company establishes provisions for estimated returns, as well as other sales allowances, concurrently with the recognition of revenue. The provisions are established based upon consideration of a variety of factors, including, among other things, recent and historical return rates for both specific products and distributors and the impact of any new product releases and projected economic conditions. Product returns are provided for in the consolidated financial statements and have historically been within management’s expectations. Allowances for estimated product returns amounted to approximately $1.4 million and $2.2 million at December 31, 2015 and December 31, 2014 , respectively. The Company also records estimated reductions to revenue for customer programs and incentive offerings including volume-based incentives. The Company could take actions to increase its customer incentive offerings, which could result in an incremental reduction to revenue at the time the incentive is offered. Product Concentration The Company derives a substantial portion of its revenues from its Workspace Services solutions, which include its XenDesktop and XenApp products and related services, and anticipates that these products and future derivative products and product lines based upon this technology will continue to constitute a majority of its revenue. The Company has recently experienced declines in sales and could continue to experience declines in demand for its Workspace Services solutions and other products, whether as a result of general economic conditions, the delay or reduction in technology purchases, new competitive product releases, price competition, lack of success of its strategic partners, technological change or other factors. Cost of Net Revenues Cost of product and license revenues consists primarily of hardware, product media and duplication, manuals, packaging materials, shipping expense and server capacity costs. In addition, the Company is a party to licensing agreements with various entities, which give the Company the right to use certain software code in its products or in the development of future products in exchange for the payment of fixed fees or amounts based upon the sales of the related product. The licensing agreements generally have terms ranging from one to five years, and generally include renewal options. However, some agreements are perpetual unless expressly terminated. Royalties and other costs related to these agreements are included in cost of net revenues. Cost of services and maintenance revenue consists primarily of compensation and other personnel-related costs of providing technical support and consulting, as well as costs of hosting the Company’s Mobility Apps products. Also included in cost of net revenues is amortization and impairment of product related intangible assets which includes acquired core and product technology and associated patents. 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. Effective January 1, 2015, the functional currency of the Company’s wholly-owned foreign subsidiaries of its Mobility Apps business unit became the U.S. dollar as a result of a reorganization in the foreign subsidiaries' operations. Prior to January 1, 2015, the functional currency of the Company’s wholly-owned foreign subsidiaries of its Mobility Apps business unit was the currency of the country in which each subsidiary is located. The Company translated assets and liabilities of these foreign subsidiaries at exchange rates in effect at the balance sheet date and included accumulated net translation adjustments in equity as a component of Accumulated other comprehensive loss. The change in functional currency is applied on a prospective basis, therefore a ny gains and losses that were previously recorded in Accumulated other comprehensive loss remain unchanged from January 1, 2015. Foreign currency transaction gains and losses are the result of exchange rate changes on transactions denominated in currencies other than the functional currency, including U.S. dollars. The remeasurement of those foreign currency transactions is included in determining net income or loss for the period of exchange. See Note 11 for information on the Company's Enterprise and Service Provider and Mobility Apps business units. Derivatives and Hedging Activities In accordance with the authoritative guidance, the Company records derivatives at fair value as either assets or liabilities on the balance sheet. For derivatives that are designated as and qualify as effective cash flow hedges, the portion of gain or loss on the derivative instrument effective at offsetting changes in the hedged item is reported as a component of Accumulated other comprehensive loss and reclassified into earnings as operating expense, net, when the hedged transaction affects earnings. Derivatives not designated as hedging instruments are adjusted to fair value through earnings as Other expense, net, in the period during which changes in fair value occur. The application of the authoritative guidance could impact the volatility of earnings. The Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objective and strategy for undertaking various hedge transactions. This process includes attributing all derivatives that are designated as cash flow hedges to floating rate assets or liabilities or forecasted transactions. The Company also formally assesses, both at the inception of the hedge and on an ongoing basis, whether each derivative is highly effective in offsetting changes in cash flows of the hedged item. Fluctuations in the value of the derivative instruments are generally offset by changes in the hedged item; however, if it is determined that a derivative is not highly effective as a hedge or if a derivative ceases to be a highly effective hedge, the Company will discontinue hedge accounting prospectively for the affected derivative. The Company is exposed to risk of default by its hedging counterparties. Although this risk is concentrated among a limited number of counterparties, the Company’s foreign exchange hedging policy attempts to minimize this risk by placing limits on the amount of exposure that may exist with any single financial institution at a time. Pension Liability The Company provides retirement benefits to certain employees who are not U.S. based. Generally, benefits under these programs are based on an employee’s length of service and level of compensation. The majority of these programs are commonly referred to as termination indemnities, which provide retirement benefits in accordance with programs mandated by the governments of the countries in which such employees work. The Company had accrued $13.8 million and $15.6 million for these pension liabilities at December 31, 2015 and 2014 , respectively. Expenses for the programs for 2015 , 2014 and 2013 amounted to $3.8 million , $3.2 million and $3.5 million , respectively. Advertising Costs The Company expenses advertising costs as incurred. The Company has advertising agreements with, and purchases advertising from, online media providers to advertise its products. The Company also has cooperative advertising agreements with certain distributors and resellers whereby the Company will reimburse distributors and resellers for qualified advertising of Company products. Reimbursement is made once the distributor, reseller or provider provides substantiation of qualified expenses. The Company estimates the impact of these expenses and recognizes them at the time of product sales as a reduction of net revenue in the accompanying consolidated statements of income. The total costs the Company recognized related to advertising were approximately $144.1 million , $150.1 million and $146.5 million , during the years ended December 31, 2015 , 2014 and 2013 , respectively. Income Taxes The Company and one or more of its subsidiaries is subject to United States federal income taxes, as well as income taxes of multiple state and foreign jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal, state and local, or non-U.S. income tax examinations by tax authorities for years prior to 2012. In the ordinary course of global business, there are transactions for which the ultimate tax outcome is uncertain; thus, judgment is required in determining the worldwide provision for income taxes. The Company provides for income taxes on transactions based on its estimate of the probable liability. The Company adjusts its provision as appropriate for changes that impact its underlying judgments. Changes that impact provision estimates include such items as jurisdictional interpretations on tax filing positions based on the results of tax audits and general tax authority rulings. Due to the evolving nature of tax rules combined with the large number of jurisdictions in which the Company operates, estimates of its tax liability and the realizability of its deferred tax assets could change in the future, which may result in additional tax liabilities and adversely affect the Company’s results of operations, financial condition and cash flows. The Company is req

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS 2015 Acquisitions Sanbolic On January 8, 2015, the Company acquired all of the issued and outstanding securities of Sanbolic, Inc. (“Sanbolic”). The Company expected the Sanbolic technology, combined with XenDesktop, XenApp, and XenMobile products, would enable it to develop a range of differentiated solutions that would have reduced the complexity of Microsoft Windows application delivery and desktop virtualization deployments. Sanbolic became part of the Company's Enterprise and Service Provider segment. The total cash consideration for this transaction was approximately $89.4 million , net of $0.2 million cash acquired. Transaction costs associated with the acquisition were $0.5 million , of which the Company expensed $0.3 million during the year ended December 31, 2015 and are included in General and administrative expense in the accompanying consolidated statements of income. In addition, in connection with the acquisition, the Company assumed non-vested stock units which were converted into the right to receive, in the aggregate, up to 37,057 shares of the Company's common stock, for which the vesting period began on the closing of the transaction. During 2015, the Company's management performed a comprehensive operational review which included an evaluation of all its products. In connection with this review, the Company determined that the Sanbolic technology was a non-core solution and that the related product offerings will no longer be developed by the Company. As a result, the Company impaired the intangible assets related to this acquisition. Refer to Note 2 for further information about intangible assets. Grasshopper On May 18, 2015, the Company acquired all of the membership interests of Grasshopper Group, LLC (“Grasshopper”), a leading provider of cloud-based phone solutions for small businesses. With the acquisition, the Company will expand its breadth of communication and collaboration solutions for small businesses, including GoToMeeting, GoToTraining, GoToWebinar, OpenVoice and ShareFile. Grasshopper became part of the Mobility Apps segment. Total cash consideration for this transaction was approximately $161.5 million , net of $3.6 million cash acquired. Transaction costs associated with the acquisition were $0.3 million , all of which the Company expensed during the year ended December 31, 2015 and are included in General and administrative expense in the accompanying consolidated statements of income. In addition, in connection with the acquisition, the Company assumed non-vested stock units which were converted into the right to receive, in the aggregate, up to 105,765 shares of the Company's common stock, for which the vesting period commenced on the closing of the transaction. Purchase Accounting for the 2015 Acquisitions The purchase prices for companies acquired during the year ended December 31, 2015 , which include Sanbolic, Grasshopper, and another 2015 acquisition (collectively, the "2015 Acquisitions"), were allocated to the acquired net tangible and intangible assets based on estimated fair values as of the date of each acquisition. The allocation of the total purchase prices is summarized below (in thousands): Sanbolic Grasshopper Other 2015 Acquisition Purchase Price Allocation Asset Life Purchase Price Allocation Asset Life Purchase Price Allocation Asset Life Current assets $ 581 $ 4,818 $ 205 Property and equipment — 467 Various — Intangible assets 45,300 Various 71,400 Various 980 5 years Goodwill 61,641 Indefinite 99,686 Indefinite 5,285 Indefinite Other assets — 80 — Assets acquired 107,522 176,451 6,470 Current liabilities assumed 1,454 11,181 42 Long-term liabilities assumed 3,175 158 — Deferred tax liabilities, non-current 13,297 — 306 Net assets acquired $ 89,596 $ 165,112 $ 6,122 Current assets acquired in connection with the 2015 Acquisitions consisted primarily of cash, accounts receivable, deferred tax assets and other short term assets. Current liabilities assumed in connection with the 2015 Acquisitions consisted primarily of accounts payable, other accrued expenses and short-term debt. Long-term liabilities assumed in connection with the Sanbolic and Grasshopper acquisitions consisted of long-term debt and other long-term liabilities. Both short-term and long-term debt were paid in full subsequent to the Sanbolic and Grasshopper acquisition dates. Goodwill from the Sanbolic acquisition was assigned to the Enterprise and Service Provider segment whereas goodwill from the Grasshopper acquisition and the other 2015 acquisition was assigned to the Mobility Apps segment. The goodwill related to the Sanbolic acquisition and the other 2015 acquisition is not deductible for tax purposes whereas the goodwill related to the Grasshopper acquisition is deductible for tax purposes. See Note 11 for segment information. The goodwill amount from the 2015 Acquisitions is comprised primarily of expected synergies from combining operations and other intangible assets that do not qualify for separate recognition. Revenue from the Sanbolic acquisition is included in the Enterprise and Service Provider segment and revenue from the Grasshopper acquisition and the other 2015 acquisition is included in the Mobility Apps segment. The Company has included the effect of the 2015 Acquisitions in its results of operations prospectively from the respective dates of acquisitions. Identifiable intangible assets acquired in connection with the 2015 Acquisitions (in thousands) and the weighted-average lives are as follows: Sanbolic Asset Life Grasshopper Asset Life Other 2015 Acquisition Asset Life Core and product technologies $ 43,800 5 and 6 years $ 25,000 7 years $ 980 5 years Customer relationships 1,500 2 years 37,900 5 years — Telecommunication carrier relationships — 7,900 2 years — Tradename — 600 2 years — Total $ 45,300 $ 71,400 $ 980 The following unaudited pro-forma information combines the consolidated results of the operations of the Company and the 2015 Acquisitions as if the acquisitions had occurred on January 1, 2014, the first day of the Company's fiscal year 2014 (in thousands, except per share data): Twelve Months Ended December 31, 2015 2014 Revenues $ 3,289,264 $ 3,170,128 Income from operations 349,577 276,344 Net income 318,794 234,957 Per share - basic 2.01 1.38 Per share - diluted 1.99 1.37 2014 Acquisitions Framehawk In January 2014, the Company acquired all of the issued and outstanding securities of Framehawk, Inc. ("Framehawk"). The Framehawk solution, which optimizes the delivery of virtual desktops and applications to mobile devices, was combined with HDX technology in the Citrix XenApp and XenDesktop products to deliver an improved user experience under adverse network conditions. Framehawk became part of the Company's Enterprise and Service Provider segment. The total cash consideration for this transaction was approximately $24.2 million , net of $0.2 million of cash acquired. Transaction costs associated with the acquisition were approximately $0.1 million , all of which the Company expensed during the year ended December 31, 2014 and are included in General and administrative expense in the accompanying consolidated statements of income. RightSignature In October 2014, the Company acquired all of the membership interests of RightSignature, LLC. ("RightSignature”). The RightSignature technology expands the Workflow Cloud beyond storage and file transfer to supporting e-signature and approval workflows. RightSignature became a part of the Company's Mobility Apps segment. The total cash consideration for this transaction was approximately $37.8 million , net of $1.1 million of cash acquired. Transaction costs associated with the acquisition were approximately $0.2 million , all of which the Company expensed during the year ended December 31, 2014 and are included in General and administrative expense in the accompanying consolidated statements of income. In addition, in connection with the acquisition, the Company assumed non-vested stock units which were converted into the right to receive, in the aggregate, up to 67,500 of the Company's common stock, for which the vesting period began on the closing of the transaction. 2014 Other Acquisitions During the second quarter of 2014, the Company acquired all of the issued and outstanding securities of a privately-held company. The total cash consideration for this transaction was approximately $17.2 million , net of $0.8 million of cash acquired. This business became part of the Company's Enterprise and Service Provider segment. Transaction costs associated with the acquisition were approximately $0.1 million , all of which the Company expensed during the year ended December 31, 2014 and are included in General and administrative expense in the accompanying consolidated statements of income. In the fourth quarter of 2014 the Company acquired all of the issued and outstanding securities of two privately-held companies for total cash consideration of approximately $19.9 million , net of $0.2 million of cash acquired. The businesses became part of the Company's Enterprise and Service Provider segment. In addition, in connection with one of the acquisitions, the Company assumed non-vested stock units which were converted into the right to receive, in the aggregate, up to 23,430 shares of the Company's common stock, for which the vesting period began on the closing of the transaction. Transaction costs associated with the acquisitions were not significant. Subsequent Event On January 8, 2016, the Company acquired certain monitoring technology from a privately-held company for total cash consideration of $23.6 million . The acquisition provides a monitoring solution for Citrix's products as it relates to Microsoft Windows applications and desktop delivery. In connection with this transaction, the Company entered into a three -year contract for outsourced development for the maintenance and roadmap updates of the acquired monitoring technology.

Investments

Investments	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [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): December 31, 2015 December 31, 2014 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 $ 530,981 $ 757 $ (1,216 ) $ 530,522 $ 637,474 $ 1,296 $ (457 ) $ 638,313 Corporate securities 699,210 90 (1,929 ) 697,371 795,255 232 (1,372 ) 794,115 Municipal securities 14,872 14 (8 ) 14,878 48,744 17 (31 ) 48,730 Government securities 152,376 9 (340 ) 152,045 121,431 37 (256 ) 121,212 Total $ 1,397,439 $ 870 $ (3,493 ) $ 1,394,816 $ 1,602,904 $ 1,582 $ (2,116 ) $ 1,602,370 The change in net unrealized (losses) gains on available-for-sale securities recorded in Other comprehensive (loss) income includes unrealized (losses) gains 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, as well as prepayments of available-for-sale investments purchased at a premium. This reclassification has no effect on total comprehensive income or equity and was not material for all periods presented. See Note 16 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 December 31, 2015 were approximately six months and three years, respectively. Realized Gains and Losses on Available-for-sale Investments For the years ended December 31, 2015 and 2014 , the Company had realized gains on the sales of available-for-sale investments of $0.8 million and $1.9 million , respectively. For the years ended December 31, 2015 and 2014 , the Company had realized losses on available-for-sale investments of $1.0 million and $0.5 million , respectively, primarily related to prepayments at par of securities purchased at a premium. All realized gains and losses related to the sales of available-for-sale investments are included in Other expense, net, in the accompanying consolidated statements of income. The Company continues to monitor its overall investment portfolio and if the credit ratings of the issuers of its investments deteriorate or if the issuers experience financial difficulty, including bankruptcy, the Company may be required to make adjustments to the carrying value of the securities in its investment portfolio and recognize impairment charges for declines in fair value that are determined to be other-than-temporary. 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 were $3.5 million and $2.1 million as of December 31, 2015 and 2014 , respectively. Because the Company does not intend to sell any of its investments in an unrealized loss position and it is more likely than not that it will not be required to sell the securities before the recovery of its amortized cost basis, which may not occur until maturity, it does not consider the securities to be other-than-temporarily impaired. Cost Method Investments The Company held direct investments in privately-held companies of approximately $19.9 million and $16.6 million as of December 31, 2015 and 2014 , respectively, which are accounted for based on the cost method and are included in Other assets in the accompanying consolidated balance sheets. The Company periodically reviews these investments for impairment. If the Company determines that an other-than-temporary impairment has occurred, it will write-down the investment to its fair value. During 2015 and 2014 , certain companies in which the Company held direct investments were acquired by third parties and as a result of these sales transactions the Company recorded gains of $8.7 million and $2.9 million , respectively, which was included in Other expense, net in the accompanying consolidated statements of income. The Company determined that certain cost method investments were impaired during 2015 , 2014 and 2013 and recorded a total charge of $3.3 million , $8.3 million , and $3.7 million , respectively, which is included in Other expense, net in the accompanying consolidated statements of income. See Note 5 for more information.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
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 gathers observable inputs for all of the Company’s fixed income securities from a variety of industry data providers including, for example, large custodial institutions and other third-party sources. Once the observable inputs are gathered by the Service, all data points are considered and an average price is determined. 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 December 31, 2015 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 $ 261,962 $ 261,962 $ — $ — Money market funds 102,968 102,968 — — Corporate securities 3,588 — 3,588 — Available-for-sale securities: Agency securities 530,522 — 530,522 — Corporate securities 697,371 — 695,809 1,562 Municipal securities 14,878 — 14,878 — Government securities 152,045 — 152,045 — Prepaid expenses and other current assets: Foreign currency derivatives 1,063 — 1,063 — Total assets $ 1,764,397 $ 364,930 $ 1,397,905 $ 1,562 Accrued expenses and other current liabilities: Foreign currency derivatives 3,678 — 3,678 — Total liabilities $ 3,678 $ — $ 3,678 $ — As of December 31, 2014 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 $ 230,370 $ 230,370 $ — $ — Money market funds 29,512 29,512 — — Corporate securities 267 — 267 — Available-for-sale securities: Agency securities 638,313 — 638,313 — Corporate securities 794,115 — 788,042 6,073 Municipal securities 48,730 — 48,730 — Government securities 121,212 — 121,212 — Prepaid expenses and other current assets: Foreign currency derivatives 1,206 — 1,206 — Total assets $ 1,863,725 $ 259,882 $ 1,597,770 $ 6,073 Accrued expenses and other current liabilities: Foreign currency derivatives 9,692 — 9,692 — Total liabilities $ 9,692 $ — $ 9,692 $ — The Company’s fixed income available-for-sale security portfolio generally consists of high quality, 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 all 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 Recurring Basis Using Significant Unobservable Inputs (Level 3) The Company has invested in convertible debt securities of certain early-stage entities that are classified as available-for-sale investments. As quoted prices in active markets or other observable inputs were not available for these investments, in order to measure them at fair value, the Company utilized a discounted cash flow model using a discount rate reflecting the market risk inherent in holding securities of an early-stage enterprise, adjusted by the probability-weighted exit possibilities associated with the convertible debt securities. This methodology required the Company to make assumptions that were not directly or indirectly observable regarding the fair value of the convertible debt securities; accordingly they are a Level 3 valuation and included in the table below. Investments (in thousands) Balance at December 31, 2014 $ 6,073 Purchases of Level 3 securities 1,775 Proceeds received on Level 3 securities (501 ) Total net realized losses included in earnings (838 ) Transfers out of Level 3 (4,947 ) Balance at December 31, 2015 $ 1,562 Transfers out of Level 3 relate to certain of the Company's investments in convertible debt securities of early-stage entities that were reclassified from available-for-sale investments to cost method investments upon conversion to equity ownership. These amounts are included in Other assets in the accompanying consolidated balance sheets. Realized losses included in earnings for the period are reported in Other expense, net in the accompanying consolidated statements of income. Assets Measured at Fair Value on a Non-recurring Basis Using Significant Unobservable Inputs (Level 3) During 2015 , certain cost method investments with a combined carrying value of $3.4 million were determined to be impaired and have been written down to their fair values of $0.1 million , resulting in impairment charges of $3.3 million . During 2014 , certain cost method investments with a combined carrying value of $8.3 million were determined to be impaired and have been written down to their fair values of zero resulting in impairment charges of $8.3 million . The impairment charges are included in Other expense, net in the accompanying consolidated financial statements for the years ended December 31, 2015 and 2014 . In determining the fair value of cost method investments, the Company considers many factors including but not limited to operating performance of the investee, the amount of cash that the investee has on-hand, the ability to obtain additional financing and the overall market conditions in which the investee operates. The fair value of the cost method investment represents a Level 3 valuation as the assumptions used in valuing these investments were not directly or indirectly observable. See Note 4 for more information regarding cost method investments. 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. These non-recurring fair value measurements are categorized as Level 3 significant unobservable inputs. See Note 2 to the Company's consolidated financial statements for detailed information related to Goodwill and Intangible Assets. Additional Disclosures Regarding Fair Value Measurements The carrying value of accounts receivable, accounts payable and accrued expenses and other current liabilities approximate their fair value due to the short maturity of these items. As of December 31, 2015 , the fair value of the Convertible 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 year ended December 31, 2015 , and carrying value of debt instruments (carrying value excludes the equity component of the Company’s Convertible Notes classified in equity) was as follows (in thousands): Fair Value Carrying Value Convertible Senior Notes $ 1,567,364 $ 1,324,992 See Note 12 for more information on the Convertible Notes.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2015
Accounts Payable and Accrued Liabilities, Current [Abstract]
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accrued expenses consist of the following: December 31, 2015 2014 (In thousands) Accrued compensation and employee benefits $ 184,286 $ 158,142 Other accrued expenses 133,182 139,937 Total $ 317,468 $ 298,079

Employee Stock-Based Compensati

Employee Stock-Based Compensation and Benefit Plans	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
EMPLOYEE STOCK-BASED COMPENSATION AND BENEFIT PLANS	EMPLOYEE STOCK-BASED COMPENSATION AND BENEFIT PLANS Plans 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 December 31, 2015 , 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 2014 Equity Incentive Plan (the "2014 Plan"). 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. The 2015 ESPP has replaced the Company's Amended and Restated 2005 Employee Stock Purchase Plan (as amended, the "2005 ESPP"). In connection with certain of the Company’s acquisitions, the Company has assumed certain plans from acquired companies. The Company’s Board of Directors has provided that no new awards will be granted under the Company’s acquired stock plans. Awards previously granted under the Company's superseded and expired stock plans that are still outstanding typically expire between five and ten years from the date of grant and will continue to be subject to all the terms and conditions of such plans, as applicable. The Company’s superseded and expired stock plan includes 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. SARs and ISOs are not currently being granted. Currently, the 2014 Plan provides for the issuance of a maximum of 29,000,000 shares of common stock. In addition, shares of common stock underlying any awards granted under the Company’s Amended and Restated 2005 Equity Incentive Plan, as amended, that are forfeited, canceled or otherwise terminated (other than by exercise) are added to its shares of common stock available for issuance under the 2014 Plan. 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 December 31, 2015 , there were 26,917,012 shares of common stock reserved for issuance pursuant to the Company’s stock-based compensation plans, and the Company had authorization under its 2014 Plan to grant stock-based awards covering 20,271,829 shares of common stock. 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 the last business day of a Payment Period. 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 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 December 31, 2015 , 3,872,661 shares had been issued under the 2005 ESPP. As of December 31, 2015 , 245,029 shares have been issued under the 2015 ESPP. The Company recorded stock-based compensation costs related to its employee stock purchase plans of $7.6 million , $5.2 million and $4.9 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. Effective with the Payment Period beginning in July 2015, the purchase price to participating employees will be 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. The Company used the Black-Scholes model to estimate the fair value of its Employee Stock Purchase Plan awards with the following weighted-average assumptions: Year Ended December 31, 2015 Expected volatility factor 0.35 Risk free interest rate 0.25 % Expected dividend yield 0 % Expected life (in years) 0.5 Expense Information under the Authoritative Guidance As required by the authoritative guidance, the Company estimates forfeitures of stock awards and recognizes compensation costs only for those awards expected to vest. Forfeiture rates are determined based on historical experience. The Company also considers whether there have been any significant changes in facts and circumstances that would affect its forfeiture rate quarterly. Estimated forfeitures are adjusted to actual forfeiture experience as needed. The Company recorded stock-based compensation costs, related deferred tax assets and tax benefits of $147.4 million , $46.1 million and $52.7 million , respectively, in 2015 , $169.3 million , $46.9 million and $43.9 million , respectively, in 2014 and $183.9 million , $57.1 million and $55.7 million , respectively, in 2013 . The detail of the total stock-based compensation recognized by income statement classification is as follows (in thousands): Income Statement Classifications 2015 2014 2013 Cost of services and maintenance revenues $ 2,940 $ 2,560 $ 2,540 Research and development 47,723 55,560 63,448 Sales, marketing and services 49,315 61,925 65,549 General and administrative 47,390 49,242 52,404 Total $ 147,368 $ 169,287 $ 183,941 Non-vested Stock Units Market Performance and Service Condition Stock Units In March 2015, 2014 and 2013, the Company granted senior level employees non-vested stock unit awards representing, in the aggregate, 393,464 , 378,022 and 399,029 non-vested stock units, respectively, that vest based on certain target market performance and service conditions. The number of non-vested stock units underlying each award will be determined within sixty days of the calendar year following the end of a three -year performance period ending December 31, 2017 for the March 2015 awards, December 31, 2016 for the March 2014 awards and December 31, 2015 for the March 2013 awards. The attainment level under the award will be based on the Company's total return to stockholders over the performance period compared to the return on the Nasdaq Composite Total Return Index (the "XCMP"). If the Company's return is positive and meets or exceeds the indexed return, the number of non-vested stock units issued will be based on interpolation, 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 if the Company's return exceeds the indexed return by 40% or more. If the Company's return over the performance period is positive but underperforms the index, a number of non-vested stock units will be issued, below the target award, based on interpolation; however, no non-vested stock units will be issued if the Company's return underperforms the index by more than 20% over the performance period. In the event the Company's return to stockholders is negative but still meets or exceeds the indexed return, only 75% of the target award shall be issued. 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. 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 2015 Grant March 2014 Grant March 2013 Grant Expected volatility factor 0.14 - 0.29 0.19 - 0.38 0.16 - 0.42 Risk free interest rate 0.85 % 0.81 % 0.33 % Expected dividend yield 0 % 0 % 0 % The range of expected volatilities utilized was based on the historical volatilities of the Company's common stock and the XCMP. 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 the XCMP in order to model the stock price movements. The volatilities used were calculated over the most recent 2.76 year period, which was the remaining term of the performance period at the date of grant. 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 does not intend to pay dividends on its common stock in the foreseeable future. Accordingly, 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 $61.01 for the March 2015 grant, $56.94 for the March 2014 grant and $89.93 for the March 2013 grant. The performance metrics under the March 2013 grant were not met and therefore no stock units will be issued under this grant. Service Based Stock Units The Company also awards senior level and certain other employees 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. The remaining awards vest 100% on the third anniversary of the grant date. The Company also assumes non-vested stock units in connection with certain of its acquisitions. The assumed awards have the same three year vesting schedule. 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 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. Performance Stock Units During 2015, the Company awarded certain senior level employees 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 of the calendar year following completion of the one-year performance period ending December 31, 2016 and will be based on achievement of a specific corporate financial performance goal determined at the time of the award. 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 100% of the base 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 to 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. If the performance goals are not met, no compensation cost will be recognized and any previously recognized compensation cost will be reversed. The following table summarizes the Company's non-vested stock unit activity for the year ended December 31, 2015 : Number of Shares Weighted- Average Fair Value at Grant Date Non-vested stock units at December 31, 2014 5,037,295 $ 66.20 Granted 3,415,207 66.70 Assumed from acquisitions 142,822 64.78 Vested (1,971,312 ) 64.10 Forfeited (1,476,086 ) 69.38 Non-vested stock units at December 31, 2015 5,147,926 65.00 For the years ended December 31, 2015 , 2014 and 2013 , the Company recognized stock-based compensation expense of $135.9 million , $143.1 million and $130.2 million , respectively, related to non-vested stock units. The fair value of the non-vested stock units released in 2015 , 2014 , and 2013 was $132.9 million , $118.3 million and $95.4 million , respectively. As of December 31, 2015 , there was $238.6 million of total unrecognized compensation cost related to non-vested stock units. The unrecognized cost is expected to be recognized over a weighted-average period of 1.80 years. Stock Options Stock options granted under the 2014 Plan typically have a five -year life and vest over three years, with 33.3% of the shares underlying the option vesting on the first anniversary of the date of grant and the remainder of the underlying shares vesting in equal installments at a rate of 2.78% thereafter (the "Standard Vesting Rate"). The Company may assume stock options from certain of its acquisitions for which the vesting period is typically reset to vest over three years at the Standard Vesting Rate. See Note 3 for more information related to acquisitions. A summary of the status and activity of the Company’s fixed option awards is as follows: Options Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2014 3,577,549 $ 67.60 1.29 Exercised (1,875,339 ) 59.87 Forfeited or expired (390,098 ) 77.36 Outstanding at December 31, 2015 1,312,112 75.72 0.58 $ 5,978 Vested or expected to vest 1,311,936 75.73 0.58 $ 5,977 Exercisable at December 31, 2015 1,307,487 75.82 0.57 $ 5,857 The Company recognized stock-based compensation expense of $2.5 million , $20.9 million and $48.9 million related to options for the years ended December 31, 2015 , 2014 and 2013 , respectively. As of December 31, 2015 , unrecognized compensation cost related to stock options was not material. The total intrinsic value of stock options exercised during 2015 , 2014 and 2013 was $23.0 million , $37.1 million and $77.7 million , respectively. Stock Option Valuation Information The Company uses the Black-Scholes option pricing model to determine the fair value of stock options. There were no stock options granted and/or assumed during the year ended December 31, 2015 and 2014 . The weighted-average fair value of stock options granted and/or assumed during the year ended December 31, 2013 was $56.97 . The assumptions used to value options granted and/or assumed are as follows: Stock options granted or assumed during 2013 Expected volatility factor 0.39 Approximate risk free interest rate 0.4% Expected term (in years) 3.35 Expected dividend yield 0% Benefit Plan The Company maintains a 401(k) benefit plan allowing eligible U.S.-based employees to contribute up to 90% of their annual eligible earnings to the plan on a pretax and after-tax basis, including Roth contributions, limited to an annual maximum amount as set periodically by the IRS. The Company, at its discretion, may contribute up to $ 0.50 for each dollar of employee contribution. The Company’s total matching contribution to an employee is typically made at 3% of the employee’s annual compensation. The Company’s matching contributions were $15.9 million , $14.4 million and $12.7 million in 2015 , 2014 and 2013 , respectively. Prior to June 2015, the Company’s contributions vested over a four -year period at 25% per year. Effective in June 2015, all matching contributions vest immediately.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
CAPITAL STOCK	CAPITAL STOCK Stock Repurchase Programs The Company’s Board of Directors authorized an ongoing stock repurchase program with a total repurchase authority granted to the Company of $6.3 billion , of which $500.0 million was approved in September 2015 and an additional $400.0 million was approved in January 2016. 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 December 31, 2015 , approximately $32.7 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 offering, as well as proceeds from employee stock option exercises and the related tax benefit. The Company is authorized to make open market 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. During the year ended December 31, 2015 , the Company expended approximately $755.7 million on open market purchases under the stock repurchase program, repurchasing 10,716,850 shares of outstanding common stock at an average price of $70.52 . During the second quarter of 2014, the Company used a portion of the net proceeds from the Convertible Notes offering and existing cash and investments to repurchase an aggregate of approximately $1.5 billion of its common stock as authorized under the stock repurchase program. Of this $1.5 billion , the Company used approximately $101.0 million to purchase 1.7 million shares from certain purchasers of the Convertible Notes in privately negotiated transactions concurrently with the closing of the offering, and the remaining $1.4 billion to purchase additional shares of common stock under an Accelerated Share Repurchase ("ASR") which the Company entered into with Citibank, N.A. ("Citibank") on April 25, 2014 (the "ASR Agreement"). Under the ASR agreement, the Company paid $1.4 billion to Citibank upon consummation of the ASR and received, in the aggregate, approximately 21.8 million shares of its common stock from Citibank, including approximately 2.6 million shares delivered in October 2014 in final settlement in connection with Citibank's election to accelerate the ASR. The total number of shares of common stock that the Company repurchased under the ASR Agreement was based on the average of the daily volume-weighted average prices of the common stock during the term of the ASR Agreement, less a discount. In addition to the repurchases described above, during the year ended December 31, 2014 , the Company expended approximately $139.9 million on open market purchases under the stock repurchase program, repurchasing 2,046,400 shares of outstanding common stock at an average price of $68.36 . During the year ended December 31, 2013 , the Company expended approximately $406.3 million on open market purchases, repurchasing 6,563,986 shares of outstanding common stock at an average price of $61.90 . Shares for Tax Withholding During the years ended December 31, 2015 , 2014 and 2013 , the Company withheld 679,694 shares, 560,239 shares and 444,657 shares, respectively, from stock awards that vested. Amounts withheld to satisfy minimum tax withholding obligations that arose on the vesting of stock awards was $46.3 million , $33.7 million and $31.0 million , for 2015 , 2014 and 2013 , respectively. These shares are reflected as treasury stock in the Company's consolidated balance sheets and statements of equity. Preferred Stock The Company is authorized to issue 5,000,000 shares of preferred stock, $0.01 par value per share. No shares of such preferred stock were issued and outstanding at December 31, 2015 or 2014 .

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Leases The Company leases certain office space and equipment under various operating leases. In addition to rent, the leases require the Company to pay for taxes, insurance, maintenance and other operating expenses. Certain of these leases contain stated escalation clauses while others contain renewal options. The Company recognizes rent expense on a straight-line basis over the term of the lease, excluding renewal periods, unless renewal of the lease is reasonably assured. Rental expense for the year ended December 31, 2015 totaled approximately $97.1 million , of which $22.1 million related to charges for the consolidation of leased facilities related to restructuring activities. Rental expense for the years ended December 31, 2014 and 2013 totaled approximately $77.1 million and $70.9 million , respectively. Sublease income for the years ended December 31, 2015 , 2014 and 2013 was approximately $0.4 million , $0.3 million and $0.3 million , respectively. Lease commitments under non-cancelable operating leases with initial or remaining terms in excess of one year and sublease income associated with non-cancelable subleases, are as follows: Operating Leases Sublease Income (In thousands) Years ending December 31, 2016 $ 64,539 $ 272 2017 52,243 218 2018 46,199 204 2019 43,119 — 2020 35,363 — Thereafter 153,139 — Total $ 394,602 $ 694 Liabilities for Loss on Lease Obligations The Company recognizes liabilities for costs that will continue to be incurred under operating lease obligations for their remaining terms without economic benefit to the Company. The liabilities are measured and recorded at their fair values as of the cease-use date (the date the Company vacates the leased space and no longer derives economic benefit from the leases). The liabilities are included in Accrued expenses and other current liabilities and Other long-term liabilities in the consolidated balance sheets and the related expense is included in Restructuring expenses in the consolidated statements of income. The fair values of the liabilities are determined by discounting certain future cash flows related to the leases using a credit-adjusted risk-free interest rate as of the cease-use date (Level 3). The future cash flows that are discounted include the remaining base rentals due under the leases, reduced by the estimated sublease rentals that could be reasonably obtained for the properties even if the Company has no intention to enter into a sublease. The estimate of sublease rentals may change, which would require future changes to the liabilities for loss on lease obligations. As of December 31, 2015 , the Company's liabilities for loss on lease obligations total approximately $20.7 million , of which approximately $15.0 million relates to the Company's Santa Clara Office. The calculation of these liabilities requires judgment in estimating the timing of securing subleases for the vacant space, as well as the terms of possible subleases, including the length of the sublease periods, sublease rentals, rent concessions and other tenant incentives. While the Company believes that the assumptions used in the calculation of these liabilities are reasonable, due to the inherent uncertainties related to such assumptions, there can be no assurance that the Company will be able to secure such subleases within the timing assumed in its calculations, or at all, and with terms consistent with the assumptions used. 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 claims, suits, assessments, investigations or legal proceedings change, changes in the Company's accrued liabilities would be recorded in the period in which such determination is made. For the Other Matters referenced below, the amount of liability is not probable or the amount cannot be reasonably estimated; and, therefore, accruals have not been 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. In April 2014, John Calma, ostensibly on behalf of the Company, filed a shareholder derivative complaint against certain of the directors of the Company (and the Company as a nominal defendant) in the Court of Chancery of the State of Delaware. The complaint alleges breach of fiduciary duty, waste of corporate assets and unjust enrichment related to stock awards that they received under the Company's director compensation program. The complaint seeks the recovery of monetary damages and other relief for damages allegedly caused to the Company. The Company believes that its directors and the Company have meritorious defenses to these allegations and that it is not reasonably possible that the ultimate outcome of this suit will materially and adversely affect the Company's business, financial condition, results of operations or cash flows. Due to the nature of the Company's business, the Company is subject to patent infringement claims, including current suits against it or one or more of its wholly-owned subsidiaries alleging infringement by various Company products and services. The Company believes that it has meritorious defenses to the allegations made in its pending cases and intends to vigorously defend these lawsuits; 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 a defendant in various litigation matters generally arising out of the normal course of business. Although it is difficult to predict the ultimate outcomes of these cases, the Company believes that it is not reasonably possible that the ultimate outcomes will materially and adversely affect its business, financial position, results of operations or cash flows. 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 as of December 31, 2015 . 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. Purchase Obligations The Company has agreements with suppliers to purchase inventory and estimates its non-cancelable obligations under these agreements for the fiscal year ended December 31, 2016 to be approximately $11.4 million . The Company also has contingent obligations to purchase inventory for the fiscal year ended December 31, 2016 , which are based on amount of usage, of approximately $18.7 million . The Company does not have any purchase obligations beyond December 31, 2016 .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The United States and foreign components of income before income taxes are as follows: 2015 2014 2013 (In thousands) United States $ (3,332 ) $ 82,032 $ 142,085 Foreign 315,209 193,674 245,805 Total $ 311,877 $ 275,706 $ 387,890 The components of the provision for income taxes are as follows: 2015 2014 2013 (In thousands) Current: Federal $ 27,860 $ 22,377 $ 51,389 Foreign 43,796 30,878 37,221 State 10,238 7,710 11,605 Total current 81,894 60,965 100,215 Deferred: Federal (75,479 ) (26,922 ) (34,897 ) Foreign (2,746 ) (1,023 ) (8,413 ) State (11,153 ) (9,037 ) (8,538 ) Total deferred (89,378 ) (36,982 ) (51,848 ) Total provision $ (7,484 ) $ 23,983 $ 48,367 The following table presents the breakdown between current and non-current net deferred tax assets: December 31, 2015 2014 (In thousands) Deferred tax assets - current (1) $ — $ 45,892 Deferred tax liabilities - current (1) — (1,053 ) Deferred tax assets- non current 215,196 128,198 Deferred tax liabilities - non current (3,903 ) (8,722 ) Total net deferred tax assets $ 211,293 $ 164,315 (1) During the year ended December 31, 2015, the Company elected to early adopt an accounting standard update on income taxes on a prospective basis. The new authoritative guidance requires deferred tax liabilities and assets along with any related valuation allowance to be classified as noncurrent on the consolidated balance sheet. The December 31, 2014 consolidated balance sheet was not retrospectively adjusted. The significant components of the Company’s deferred tax assets and liabilities consisted of the following: December 31, 2015 2014 (In thousands) Deferred tax assets: Accruals and reserves $ 36,628 $ 27,105 Deferred revenue 84,631 65,541 Tax credits 41,444 43,211 Net operating losses 50,466 75,318 Other 7,527 12,878 Stock based compensation 46,582 63,993 Valuation allowance (16,673 ) (15,167 ) Total deferred tax assets 250,605 272,879 Deferred tax liabilities: Depreciation and amortization (16,113 ) (16,835 ) Acquired technology (15,825 ) (82,357 ) Prepaid expenses (7,374 ) (9,372 ) Total deferred tax liabilities (39,312 ) (108,564 ) Total net deferred tax assets $ 211,293 $ 164,315 The authoritative guidance requires a valuation allowance to reduce the deferred tax assets reported if it is not more likely than not that some portion or all of the deferred tax assets will be realized. At December 31, 2015 , the Company determined that a $16.7 million valuation allowance relating to deferred tax assets for net operating losses and tax credits was necessary. The Company does not expect to remit earnings from its foreign subsidiaries. Undistributed earnings of the Company’s foreign subsidiaries amounted to approximately $2.33 billion at December 31, 2015 and are primarily held by its foreign subsidiary in the Cayman Islands. Those earnings are considered to be permanently reinvested and, accordingly, no U.S. federal and state income taxes have been provided thereon. Upon distribution of those earnings in the form of dividends or otherwise, the Company could be subject to both U.S. income taxes (subject to an adjustment for foreign tax credits) and withholding taxes payable to various foreign countries. 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. At December 31, 2015 , the Company had $113.1 million of remaining net operating loss carry forwards in the United States from acquisitions. The utilization of these net operating loss carry forwards are limited in any one year pursuant to Internal Revenue Code Section 382 and begin to expire in 2020. At December 31, 2015 , the Company had $32.3 million of remaining net operating loss carry forwards in foreign jurisdictions that do not expire. At December 31, 2015 , the Company had research and development tax credit carry forwards of $65.6 million that begin to expire in 2018. A reconciliation of the Company’s effective tax rate to the statutory federal rate is as follows: Year Ended December 31, 2015 2014 2013 Federal statutory taxes 35.0 % 35.0 % 35.0 % State income taxes, net of federal tax benefit 0.9 1.2 1.2 Foreign operations (22.3 ) (13.8 ) (14.8 ) Permanent differences 6.1 3.3 (1.1 ) Change in deferred tax liability related to acquired intangibles (6.6 ) (5.9 ) — Tax credits (13.4 ) (13.7 ) (10.9 ) Stock option compensation 0.5 1.9 0.4 Change in accruals for uncertain tax positions (3.2 ) (0.3 ) 3.3 Other 0.6 1.0 (0.6 ) (2.4 )% 8.7 % 12.5 % The Company’s effective tax rate generally differs from the U.S. federal statutory rate of 35% due primarily to lower tax rates on earnings generated by the Company’s foreign operations that are taxed primarily in Switzerland. The Company has not provided for U.S. taxes for those earnings because it plans to reinvest all of those earnings indefinitely outside the United States. It was not practicable to determine the amount of unrecognized deferred tax liability for temporary differences related to investments in foreign and domestic subsidiaries. The Company and certain of its subsidiaries are subject to U.S. federal income taxes, as well as income taxes of multiple state and foreign jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal, state and local, or non-U.S. income tax examinations by tax authorities for years prior to 2012. During the quarter ended June 30, 2015, the Internal Revenue Service (“IRS”) concluded its field examination of the Company’s 2011 and 2012 tax years and issued proposed adjustments primarily related to transfer pricing and the research and development tax credit. In June 2015, the Company finalized its tax deficiency calculations and formally closed the audit with the IRS for the 2011 and 2012 tax years. As a result, the Company recognized a net tax benefit of $20.3 million during the second quarter of 2015 related to the settlement. The Company's effective tax rate was approximately (2.4)% and 8.7% for the year ended December 31, 2015 and 2014, respectively. The decrease in the effective tax rate when comparing the year ended December 31, 2015 to the year ended December 31, 2014 was primarily due to a change in the combination of income between the Company's U.S. and foreign operations, the decline in reserve for uncertain tax positions, as well as the impact of discrete tax benefits related to the extension of the 2015 federal research and development tax credit. A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, 2015 and 2014 is as follows (in thousands): Balance at January 1, 2014 $ 63,792 Additions based on tax positions related to the current year 5,711 Additions for tax positions of prior years 12,998 Reductions related to the expiration of statutes of limitations (4,118 ) Settlements (11,465 ) Balance at December 31, 2014 66,918 Additions based on tax positions related to the current year 6,613 Additions for tax positions of prior years 4,675 Reductions related to the expiration of statutes of limitations (9,521 ) Settlements (14,064 ) Balance at December 31, 2015 $ 54,621 The Company does not anticipate the total amount of unrecognized tax benefits will change significantly over the next 12 months. As of December 31, 2015 the Company is offsetting unrecognized tax benefits of $25.4 million against long-term deferred tax assets. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in income tax expense. During the year ended December 31, 2015 , amounts recognized related to interest and penalties were immaterial. The federal research and development credit expired on December 31, 2013. On December 19, 2014, the Tax Increase Prevention Act of 2014 was signed into law. Under this act, the federal research and development credit was retroactively extended for amounts paid or incurred after December 31, 2013 and before January 1, 2015. The effects of these changes in the tax law result in net tax benefits of approximately $12.3 million , which was recognized in the fourth quarter of 2014, the quarter in which the law was enacted. The Protecting Americans from Tax Hikes Act of 2015 was signed into law on December 18, 2015, permanently extending the research credit under Section 41 for amounts paid or incurred after December 31, 2014. Accordingly, the Company recognized $19.2 million of federal research and development credit in the fourth quarter of 2015.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
SEGMENT INFORMATION	SEGMENT INFORMATION The Enterprise and Service Provider the Mobility Apps business units constitute the Company’s two reportable segments. The Company does not engage in intercompany revenue transfers between segments. The Company’s chief operating decision maker (“CODM”) evaluates the Company’s performance based primarily on profitability from its Enterprise and Service Provider and Mobility Apps products. Segment profit for each segment includes certain research and development, sales, marketing, general and administrative expenses directly attributable to the segment as well as other corporate costs allocated to the segment and excludes certain expenses that are managed outside of the reportable segments. Costs excluded from segment profit primarily consist of certain restructuring charges, separation costs, stock-based compensation costs, charges or benefits related to significant litigation that are not anticipated to be ongoing costs, amortization and impairment of product related intangible assets, amortization and impairment of other intangible assets, net interest and other expense, net. Accounting policies of the Company’s segments are the same as its consolidated accounting policies. As part of its continued transformation, effective January 1, 2016, the Company reorganized a part of its business by creating a new Cloud Services business unit that will include the ShareFile product line. The ShareFile product line is currently included within the Company's Workflow Cloud products under the Mobility Apps segment. The Company is currently evaluating its segment reporting and goodwill reporting units for 2016 as a result of these changes. International revenues (sales outside of the United States) accounted for approximately 43.1% , 45.2% and 45.4% of the Company’s net revenues for the year ended December 31, 2015 , 2014 , and 2013 , respectively. Net revenues and segment profit for 2015 , 2014 and 2013 classified by the Company’s reportable segments, are presented below: 2015 2014 2013 (In thousands) Net revenues: Enterprise and Service Provider $ 2,544,302 $ 2,491,294 $ 2,335,562 Mobility Apps 731,292 651,562 582,872 Consolidated $ 3,275,594 $ 3,142,856 $ 2,918,434 Segment profit (1) : Enterprise and Services Provider $ 759,614 $ 589,076 $ 588,138 Mobility Apps 83,535 115,998 116,061 Unallocated expenses (2) : Amortization and impairment of intangible assets (239,915 ) (192,325 ) (139,541 ) Patent litigation charge — (20,727 ) — Other 982 — — Restructuring (100,411 ) (20,424 ) — Net interest and other (expense) income, net (38,208 ) (26,605 ) 7,173 Stock-based compensation (147,368 ) (169,287 ) (183,941 ) Separation costs (6,352 ) — — Consolidated income before income taxes $ 311,877 $ 275,706 $ 387,890 (1) Effective January 1, 2015, the Company revised its methodology for allocating certain corporate costs within General and administrative expenses to more closely align these costs to the employees directly utilizing the related services within each of its reporting segments in connection with organizational structure changes that changed the manner in which shared support services are provided. This change in presentation does not affect the Company's consolidated financial position, results from operations or cash flows. (2) Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments. Identifiable assets classified by the Company’s reportable segments are shown below. Long-lived assets consist of property and equipment, net, and are shown below. December 31, 2015 2014 (In thousands) Identifiable assets: Enterprise and Service Provider $ 4,578,436 $ 4,879,513 Mobility Apps 903,002 632,494 Total identifiable assets $ 5,481,438 $ 5,512,007 December 31, 2015 2014 (In thousands) Property and equipment, net: United States $ 294,982 $ 284,463 United Kingdom 28,851 29,556 Other countries 49,984 53,760 Total property and equipment, net $ 373,817 $ 367,779 The decreases in identifiable assets are primarily due to decreases in the Company's available for sale investments. See Note 4 for additional information regarding the Company’s investments. In fiscal years 2014 and 2013 , one distributor, Ingram Micro, accounted for 13% and 14% , respectively, of the Company’s total net revenues. The Company’s distributor arrangements with Ingram Micro consist of several non-exclusive, independently negotiated agreements with its subsidiaries, each of which covers different countries or regions. Each of these agreements is separately negotiated and is independent of any other contract (such as a master distribution agreement), one of which was individually responsible for over 10% of the Company’s total net revenues in fiscal years 2014 and 2013 . Total net revenues associated with Ingram Micro are included in the Company's Enterprise and Service Provider business unit. Revenues by product grouping for the Company’s Enterprise and Service Provider and Mobility Apps business units were as follows for the years ended: December 31, 2015 2014 2013 (In thousands) Net revenues: Enterprise and Service Provider Workspace Services revenues (1) $ 1,645,331 $ 1,606,903 $ 1,549,383 Delivery Networking revenues (2) 741,121 695,734 634,598 Professional services (3) 147,488 175,541 138,879 Other 10,362 13,116 12,702 Total Enterprise and Service Provider revenues 2,544,302 2,491,294 2,335,562 Mobility Apps revenues 731,292 651,562 582,872 Total net revenues $ 3,275,594 $ 3,142,856 $ 2,918,434 (1) Workspace Services revenues are primarily comprised of sales from the Company’s windows app delivery products, which includes XenDesktop and XenApp, and the Company's mobile app delivery products, which include XenMobile and related license updates and maintenance and support. (2) Delivery Networking revenues primarily include NetScaler, ByteMobile Smart Capacity and CloudBridge products and related license updates and maintenance and support. (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 segment and geographic location, for the years ended: December 31, 2015 2014 2013 (In thousands) Net revenues: Enterprise and Service Provider Americas $ 1,394,985 $ 1,328,851 $ 1,263,673 EMEA 866,775 859,404 785,862 Asia-Pacific 282,542 303,039 286,027 Total Enterprise and Service Provider revenues 2,544,302 2,491,294 2,335,562 Mobility Apps Americas 616,900 541,145 488,307 EMEA 91,324 87,705 73,529 Asia-Pacific 23,068 22,712 21,036 Total Mobility Apps revenues 731,292 651,562 582,872 Total net revenues $ 3,275,594 $ 3,142,856 $ 2,918,434 Export revenue represents shipments of finished goods and services from the United States to international customers, primarily in Latin America and Canada. Shipments from the United States to international customers for 2015 , 2014 and 2013 were $180.2 million , $193.8 million and $215.3 million , respectively.

Convertible Senior Notes

Convertible Senior Notes	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
CONVERTIBLE SENIOR NOTES	CONVERTIBLE SENIOR NOTES Convertible Notes Offering During 2014, the Company completed a private placement of approximately $1.44 billion principal amount of 0.500% Convertible Notes due 2019. The net proceeds from this offering were approximately $1.42 billion , after deducting the initial purchasers’ discounts and commissions and the offering expenses payable by the Company. The Company used approximately $82.6 million of the net proceeds to pay the cost of the Bond Hedges described below (after such cost was partially offset by the proceeds to the Company from the Warrant Transactions described below). The Company used the remainder of the net proceeds from the offering and a portion of its existing cash and investments to purchase an aggregate of approximately $1.5 billion of its common stock, as authorized under its share repurchase program. The Company used approximately $101.0 million to purchase shares of common stock from certain purchasers of the Convertible Notes in privately negotiated transactions concurrently with the closing of the offering, and the remaining $1.4 billion to purchase additional shares of common stock through an Accelerated Share Repurchase ("ASR") which the Company entered into with Citibank, N.A. (the “ASR Counterparty”) on April 25, 2014 (the “ASR Agreement”). The Convertible Notes are governed by the terms of an indenture, dated as of April 30, 2014 (the “Indenture”), between the Company and Wilmington Trust, National Association, as trustee (the “Trustee”). The Convertible Notes are the senior unsecured obligations of the Company and bear interest at a rate of 0.500% per annum, payable semi-annually in arrears on April 15 and October 15 of each year. The Convertible Notes will mature on April 15, 2019, unless earlier repurchased or converted. Upon conversion, the Company will pay cash up to the aggregate principal amount of the Convertible Notes to be converted and pay or deliver, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock, at the Company’s election, in respect of the remainder, if any, of the Company’s conversion obligation in excess of the aggregate principal amount of the Convertible Notes being converted. As of December 31, 2015 , none of the conditions allowing holders of the Notes to convert had been met. The conversion rate for the Convertible Notes is 11.1111 shares of common stock per $1,000 principal amount of Convertible Notes, which corresponds to a conversion price of approximately $90.00 per share of common stock. The conversion rate is subject to adjustment from time to time upon the occurrence of certain events, including, but not limited to, the issuance of certain stock dividends on common stock, the issuance of certain rights or warrants, subdivisions, combinations, distributions of capital stock, indebtedness, or assets, the payment of cash dividends and certain issuer tender or exchange offers. The Company may not redeem the Convertible Notes prior to the maturity date and no “sinking fund” is provided for the Convertible Notes, which means that the Company is not required to periodically redeem or retire the Convertible Notes. Upon the occurrence of certain fundamental changes involving the Company, holders of the Convertible Notes may require the Company to repurchase for cash all or part of their Convertible Notes in principal amounts of $1,000 or an integral multiple thereof at a repurchase price equal to 100% of the principal amount of the Convertible Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. In accounting for the issuance of the Convertible Notes, the Company separated the Convertible Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the estimated fair value of a similar liability that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the face value of the Convertible Notes as a whole. The excess of the principal amount of the liability component over its carrying amount ("debt discount") is amortized to interest expense over the term of the Convertible Notes using the effective interest method with an effective interest rate of 3.0 percent per annum. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. In accounting for the transaction costs related to the Convertible Note issuance, the Company allocated the total amount incurred to the liability and equity components based on their relative values. Issuance costs attributable to the $1.3 billion liability component are being amortized to expense over the term of the Convertible Notes, and issuance costs attributable to the $162.9 million equity component are included along with the equity component in stockholders' equity. Additionally, a deferred tax liability of $8.2 million related to a portion of the equity component transaction costs which are deductible for tax purposes is included in Other liabilities in the accompanying consolidated balance sheets. The Convertible Notes consist of the following (in thousands): December 31, 2015 Liability component Principal $ 1,437,500 Less: note discount (112,508 ) Net carrying amount 1,324,992 Equity component * $ 162,869 * Recorded in the consolidated balance sheet within additional paid-in capital. The following table includes total interest expense recognized related to the Convertible Notes (in thousands): Year Ended December 31, 2015 2014 Contractual interest expense $ 7,188 $ 4,792 Amortization of debt issuance costs 3,974 2,461 Amortization of debt discount 32,039 20,832 $ 43,201 $ 28,085 See Note 5 to the Company's consolidated financial statements for fair value disclosures related to the Company's Convertible Notes. Convertible Note Hedge and Warrant Transactions In connection with the pricing 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"), with JPMorgan Chase Bank, National Association, London Branch; Goldman, Sachs & Co.; Bank of America, N.A.; and Royal Bank of Canada (the “Option Counterparties”) and also entered into separate warrant transactions (the "Initial Warrant Transactions") with each of the Option Counterparties relating to approximately 16.0 million shares of common stock. The Bond Hedges are generally expected to reduce the potential dilution upon conversion of the Convertible Notes and/or offset any payments in cash, shares of common stock or a combination of cash and shares of common stock, at the Company’s election, that the Company is required to make in excess of the principal amount of the Convertible Notes upon conversion of any Convertible Notes, as the case may be, in the event that the market price per share of common stock, as measured under the terms of the Bond Hedges, is greater than the strike price of the Bond Hedges, which initially corresponds to the conversion price of the Convertible Notes and is 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 initial strike price of the Warrants is $120.00 per share. The Warrants will expire in ratable portions on a series of expiration dates commencing after the maturity of the Convertible Notes. The Bond Hedges and Warrants are not marked to market. The value of the Bond Hedges and Warrants were initially recorded in stockholders' equity and continue to be classified within stockholders' equity. As of December 31, 2015 , no warrants have been exercised. Aside from the initial payment of a premium to the Option Counterparties under the Bond Hedges, which amount is partially offset by the receipt of a premium under the Warrant Transactions, the Company is not required to make any cash payments to the Option Counterparties under the Bond Hedges and will not receive any proceeds if the Warrants are exercised.

Credit Facility

Credit Facility	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Credit Facility	CREDIT FACILITY Effective January 7, 2015, the Company entered into a Credit Facility 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. The proceeds of borrowings under the Credit Agreement may be used for working capital and general corporate purposes, including future acquisitions. 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 the 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 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. The weighted average interest rate for the period that amounts were outstanding under the Credit Facility was 1.82% . As of December 31, 2015 , 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 December 31, 2015 .

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	DERIVATIVE FINANCIAL INSTRUMENTS Derivatives Designated as Hedging Instruments As of December 31, 2015 , 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 twelve months and the maximum term is eighteen 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. The change in the derivative component in Accumulated other comprehensive loss includes unrealized gains or losses that arose from changes in market value of the effective portion of derivatives that were held during the period, and gains or losses that were previously unrealized but have been recognized in the same line item as the forecasted transaction in current period net income due to termination or maturities of derivative contracts. This reclassification has no effect on total comprehensive income or equity. The total cumulative unrealized loss on cash flow derivative instruments was $2.3 million at December 31, 2015 and the total cumulative unrealized loss on cash flow derivative instruments was $8.3 million at December 31, 2014 , and is included in Accumulated other comprehensive loss in the accompanying consolidated balance sheets. The net unrealized loss as of December 31, 2015 is expected to be recognized in income over the next twelve 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 expense, net. Fair Values of Derivative Instruments Asset Derivatives Liability Derivatives (In thousands) December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 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 $436 Prepaid expenses and other current assets $435 Accrued expenses and other current liabilities $2,895 Accrued expenses and other current liabilities $9,364 Asset Derivatives Liability Derivatives (In thousands) December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 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 $627 Prepaid expenses and other current assets $771 Accrued expenses and other current liabilities $783 Accrued expenses and other current liabilities $328 The Effect of Derivative Instruments on Financial Performance For the Year ended December 31, (In thousands) Derivatives in Cash Flow Hedging Relationships Amount of Gain (Loss) Recognized in Other Location of (Loss) Gain Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) Amount of (Loss) Gain Reclassified from 2015 2014 2015 2014 Foreign currency forward contracts $ 6,090 $ (11,197 ) Operating expenses $ (13,027 ) $ 2,123 There was no material ineffectiveness in the Company’s foreign currency hedging program in the periods presented. For the Year ended December 31, (In thousands) Derivatives Not Designated as Hedging Instruments Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative 2015 2014 Foreign currency forward contracts Other expense, net $ 1,669 $ 3,551 Outstanding Foreign Currency Forward Contracts As of December 31, 2015 , the Company had the following net notional foreign currency forward contracts outstanding (in thousands): Foreign Currency Currency Denomination Australian dollars AUD 1,433 Brazilian Real BRL 5,700 British pounds sterling GBP 21,510 Canadian dollars CAD 4,700 Chinese renminbi CNY 35,000 Danish krone DKK 19,000 Euro EUR 1,500 Hong Kong dollars HKD 50,813 Indian rupees INR 660,475 Japanese yen JPY 449,015 Singapore dollars SGD 11,629 Swiss francs CHF 20,400

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE The following table sets forth the computation of basic and diluted net income per share (in thousands, except per share information): Year Ended December 31, 2015 2014 2013 Numerator: Net income $ 319,361 $ 251,723 $ 339,523 Denominator: Denominator for basic earnings per share - weighted-average shares outstanding 158,874 169,879 186,672 Effect of dilutive employee stock awards: Employee stock awards 1,488 1,391 1,573 Denominator for diluted earnings per share - weighted-average shares outstanding 160,362 171,270 188,245 Basic earnings per share $ 2.01 $ 1.48 $ 1.82 Diluted earnings per share $ 1.99 $ 1.47 $ 1.80 Anti-dilutive weighted-average shares 2,151 3,026 3,647 The weighted-average number of shares outstanding used in the computation of basic and diluted earnings per share does not include the effect of the potential outstanding common stock from the Company's convertible senior notes and warrants. The effects of these potentially outstanding shares were not included in the calculation of diluted earnings per share because the effect would have been anti-dilutive. The Company uses the treasury stock method for calculating any potential dilutive effect of the conversion spread on its Convertible Senior Notes (the "Convertible Notes") on diluted earnings per share, if applicable, as upon conversion, the Company will pay cash up to the aggregate principal amount of the Convertible Notes to be converted and pay or deliver, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock, at the Company’s election, in respect of the remainder, if any, of the Company’s conversion obligation in excess of the aggregate principal amount of the Convertible Notes being converted. The conversion spread will have a dilutive impact on diluted earnings per share when the average market price of the Company’s common shares for a given period exceeds the conversion price of $90.00 per share. For the year ended December 31, 2015 , the Convertible Notes have been excluded from the computation of diluted earnings per share as the effect would be anti-dilutive since the conversion price of the Convertible Notes exceeded the average market price of the Company’s common stock. In addition, the Company uses the treasury stock method for calculating any potential dilutive effect related to the warrants. See Note 12 to the Company's consolidated financial statements for detailed information on the Convertible Notes offering.

Comprehensive Income

Comprehensive Income	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
COMPREHENSIVE INCOME	COMPREHENSIVE INCOME The changes in Accumulated other comprehensive loss by component, net of tax, are as follows (in thousands): Foreign currency Unrealized gain (loss) on available-for-sale securities Unrealized gain (loss) on derivative instruments Other comprehensive loss on pension liability Total (In thousands) Balance at December 31, 2014 $ (16,346 ) $ (990 ) $ (8,345 ) $ (11,109 ) $ (36,790 ) Other comprehensive income (loss) before reclassifications — (2,080 ) (6,937 ) 4,083 (4,934 ) Amounts reclassified from Accumulated other comprehensive loss — 170 13,027 — 13,197 Net current period other comprehensive income (loss) — (1,910 ) 6,090 4,083 8,263 Balance at December 31, 2015 $ (16,346 ) $ (2,900 ) $ (2,255 ) $ (7,026 ) $ (28,527 ) 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 (in thousands): For the Twelve Months Ended December 31, 2015 (In thousands) Details about Accumulated other comprehensive loss components Amount reclassified from Accumulated other comprehensive loss, net of tax Affected line item in the Consolidated Statements of Income Unrealized net loss on available-for-sale securities $ 170 Other expense, net Unrealized net loss on cash flow hedges 13,027 Operating expenses * $ 13,197 * Operating expenses amounts allocated to Research and development, Sales, marketing and services, and General and administrative are not individually significant.

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
RESTRUCTURING	RESTRUCTURING 2015 Other Restructuring Program On November 17, 2015, the Company announced the implementation of a restructuring program that will focus on simplification of the Company’s enterprise go-to-market motion and roles while improving coverage, reflect changes in the Company’s product focus, and balance resources with demand across the Company’s marketing, general and administration areas. The 2015 Other Restructuring Program calls for the elimination of approximately 700 full-time positions, of which 350 were communicated in 2015. During the year ended December 31, 2015 , the Company incurred costs of $29.7 million associated with the program. The Company currently expects to record in the aggregate approximately $55.0 million to $60.0 million in pre-tax restructuring charges associated with this program. The majority of these charges are related to employee severance, outplacement, professional service fees, and facility closing costs. The Company currently anticipates completing the activities related to the 2015 Other Restructuring Program during the first half of fiscal year 2016. 2015 Restructuring Program On January 28, 2015, the Company announced the implementation of a restructuring program designed to increase strategic focus and operational efficiency and began to execute against the program in February 2015. As a result, the Company eliminated approximately 700 full-time positions in the first half of 2015. During the year ended December 31, 2015 , the Company incurred costs of $68.9 million , primarily related to employee severance arrangements and the consolidation of leased facilities. The majority of the activities related to the 2015 Restructuring Program were substantially completed by the end of 2015. 2014 Restructuring Program During the first quarter of 2014, the Company announced the implementation of the 2014 Restructuring Program. The purpose of this program was to better align resources to strategic initiatives and resulted in the Company reducing its headcount by approximately 325 full-time positions. The pre-tax charges incurred were primarily related to severance and other costs directly related to the reduction of the Company's workforce. The activities under the 2014 Restructuring Program were substantially completed as of the end of the first quarter of 2015. As of December 31, 2015 , total charges related to the 2014 Restructuring Program incurred since inception were $22.2 million , primarily related to employee severance and related costs. Restructuring Charges by Segment Restructuring charges related to the reduction of the Company's headcount by segment consists of the following (in thousands): Year ended Year ended December 31, 2015 December 31, 2014 2014 Restructuring Program Enterprise and Service Provider $ 1,724 $ 14,092 Mobility Apps 50 6,332 2015 Restructuring Program Enterprise and Service Provider 67,548 — Mobility Apps 1,357 — 2015 Other Restructuring Program Enterprise and Service Provider 27,680 — Mobility Apps 2,052 — Total restructuring charges $ 100,411 $ 20,424 Restructuring accruals The activity in the Company’s restructuring accruals for the year ended December 31, 2015 is summarized as follows (in thousands): 2014 Restructuring Program 2015 Restructuring Program 2015 Other Restructuring Program Total Balance at January 1, 2015 $ 2,780 $ — $ — $ 2,780 Employee severance and related costs 2,060 44,837 29,732 76,629 Consolidation of leased facilities — 22,100 — 22,100 Payments (3,433 ) (44,243 ) (13,151 ) (60,827 ) Reversal of previous charges (286 ) — — (286 ) Balance at December 31, 2015 $ 1,121 $ 22,694 $ 16,581 $ 40,396 As of December 31, 2015 , the $40.4 million in outstanding restructuring accruals primarily relates to the Enterprise and Service Provider segment.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2015
New Accounting Pronouncement or Change in Accounting Principle, Retrospective Adjustments [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS In November 2015, the Financial Accounting Standards Board issued an accounting standard update on income taxes. The new authoritative guidance requires deferred tax liabilities and assets, along with any related valuation allowance, to be classified as noncurrent on the consolidated balance sheet. This standard is required to be adopted for annual periods beginning after December 15, 2016, including interim periods within that annual period, with early adoption permitted. The amendment may be applied either prospectively to all deferred tax liabilities and assets or retrospectively to all periods presented. The Company elected to prospectively adopt the accounting standard in the beginning of the fourth quarter of 2015. Prior periods in the Company's Consolidated Financial Statements were not retrospectively adjusted. In September 2015, the Financial Accounting Standards Board issued an accounting standard update on business combinations. The new guidance requires that an acquirer in a business combination recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined, including the cumulative effect of the change in provisional amount as if the accounting had been completed as of the acquisition date. The adjustments related to previous reporting periods since the acquisition date must be disclosed by income statement line item either on the face of the income statement or in the notes. The guidance becomes effective for fiscal years and interim reporting periods beginning on or after December 15, 2015, with early adoption permitted. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial position, results of operations and cash flows. In April 2015, the Financial Accounting Standards Board issued an accounting standard update on the presentation of debt issuance costs. The new guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The guidance becomes effective for fiscal years and interim reporting periods beginning on or after December 15, 2015, with early adoption permitted. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial position, results of operations and cash flows. In May 2014, the Financial Accounting Standards Board issued an accounting standard update on revenue recognition. The new guidance creates a single, principle-based model for revenue recognition and expands and improves disclosures about revenue. In July 2015, the Financial Accounting Standards Board issued an accounting standard update that defers the effective date of the new revenue recognition standard by one year. The new guidance is effective for annual reporting periods beginning on or after December 15, 2017, and must be adopted using either a full retrospective approach for all periods presented in the period of adoption or a modified retrospective approach. The Company has initiated an assessment of its systems, data and processes related to the implementation of this accounting standard, which is expected to be completed during 2016. The Company is currently evaluating the potential impact of this standard on its financial position and results of operations.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Data [Abstract]
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)	CITRIX SYSTEMS, INC. SUPPLEMENTAL FINANCIAL INFORMATION QUARTERLY FINANCIAL INFORMATION (UNAUDITED) First Quarter Second Quarter Third Quarter Fourth Quarter Total Year (In thousands, except per share amounts) 2015 Net revenues $ 760,802 $ 796,759 $ 813,270 $ 904,763 $ 3,275,594 Gross margin 628,196 664,008 667,016 702,010 2,661,230 Income from operations 51,732 122,149 63,798 112,406 350,085 Net income 28,887 103,275 55,925 131,274 319,361 Earnings per share - basic 0.18 0.64 0.35 0.85 2.01 Earnings per share - diluted 0.18 0.64 0.35 0.84 1.99 First Quarter Second Quarter Third Quarter Fourth Quarter Total Year (In thousands, except per share amounts) 2014 Net revenues $ 750,819 $ 781,560 $ 758,994 $ 851,483 $ 3,142,856 Gross margin 616,493 606,304 623,009 676,831 2,522,637 Income from operations 71,887 54,419 58,597 117,408 302,311 Net income 55,939 53,024 47,532 95,228 251,723 Earnings per share - basic 0.30 0.31 0.29 0.59 1.48 Earnings per share - diluted 0.30 0.31 0.29 0.58 1.47 The sum of the quarterly net income per share amounts do not add to the annual earnings per share amount due to the weighting of common and common equivalent shares outstanding during each of the respective periods.

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
VALUATION AND QUALIFYING ACCOUNTS	CITRIX SYSTEMS, INC. SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS Beginning of Period Charged to Expense Charged to Other Accounts Deductions Balance at End of Period (In thousands) 2015 Deducted from asset accounts: Allowance for doubtful accounts $ 3,791 $ 5,664 $ — $ 3,174 (2 ) $ 6,281 Allowance for returns 2,185 — 3,276 (1 ) 4,023 (4 ) 1,438 Valuation allowance for deferred tax assets 15,167 — 1,506 (5 ) — 16,673 2014 Deducted from asset accounts: Allowance for doubtful accounts $ 3,292 $ 2,861 $ 76 (3 ) $ 2,438 (2 ) $ 3,791 Allowance for returns 2,062 — 5,049 (1 ) 4,926 (4 ) 2,185 Valuation allowance for deferred tax assets 26,465 — (11,298 ) (5 ) — 15,167 2013 Deducted from asset accounts: Allowance for doubtful accounts $ 3,883 $ 1,046 $ — $ 1,637 (2 ) $ 3,292 Allowance for returns 2,564 — 4,473 (1 ) 4,975 (4 ) 2,062 Valuation allowance for deferred tax assets 18,185 — 8,280 (5 ) — 26,465 (1) Charged against revenues. (2) Uncollectible accounts written off, net of recoveries. (3) Adjustments from acquisitions. (4) Credits issued for returns. (5) Related to deferred tax assets on foreign tax credits, net operating loss carryforwards, and depreciation.

Significant Accounting Polici28

Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Consolidation Policy	Consolidation Policy The 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. All significant transactions and balances between the Company and its subsidiaries have been eliminated in consolidation.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents at December 31, 2015 and 2014 include marketable securities, which are primarily money market funds, commercial paper, agency, and government securities, municipal securities and corporate securities with initial or remaining contractual maturities when purchased of three months or less.
Investments	Investments Short-term and long-term investments at December 31, 2015 and 2014 primarily consist of agency securities, corporate securities, municipal securities and government securities. Investments classified as available-for-sale 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 4 for investment information.
Accounts Receivable	Accounts Receivable The Company’s accounts receivable are attributable primarily to VARs, VADs and end customers. Collateral is generally not required. The Company also maintains allowances for doubtful accounts for estimated losses resulting from the inability of the Company’s customers to make payments which includes both general and specific reserves. The Company periodically reviews these estimated allowances by conducting an analysis of the customer's payment history and creditworthiness, the age of the trade receivable balances and current economic conditions that may affect a customer’s ability to make payments. Based on this review, the Company specifically reserves for those accounts deemed uncollectible. When receivables are determined to be uncollectible, principal amounts of such receivables outstanding are deducted from the allowance.
Inventory	Inventory Inventories are stated at the lower of cost or market on a standard cost basis, which approximates actual cost.
Property and Equipment	Property and Equipment Property and equipment is stated at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which is generally three years for computer equipment and software, the lesser of the lease term or ten years for leasehold improvements, which is the estimated useful life, seven years for office equipment and furniture and the Company’s enterprise resource planning system and 40 years for buildings.
Long-Lived Assets	Long-Lived Assets The Company reviews for impairment of long-lived assets and certain identifiable intangible assets to be held and used whenever events or changes in circumstances indicate that the carrying amount of such assets may not be fully recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. Measurement of an impairment loss is based on the fair value of the asset compared to its carrying value. Long-lived assets and certain identifiable intangible assets to be disposed of are reported at the lower of carrying amount or fair value less costs to sell.
Goodwill	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. There was no impairment of goodwill or indefinite lived intangible assets as a result of the annual impairment tests analyses completed during the fourth quarters of 2015 and 2014 , respectively. The authoritative guidance provides entities with an option to perform a qualitative assessment to determine whether further quantitative impairment testing is necessary. The Company performed the qualitative assessment when it performed its goodwill impairment test in the fourth quarter of 2015 . As a result of the qualitative analysis, no further quantitative impairment test was deemed necessary. In-process R&D acquired in connection with the Company's acquisitions was not significant.
Intangible Assets	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 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.
Software Development Costs	Software Development Costs The authoritative guidance requires certain internal software development costs related to software to be sold to be capitalized upon the establishment of technological feasibility. The Company's software development costs incurred subsequent to achieving technological feasibility have not been significant and substantially all software development costs have been expensed as incurred.
Internal Use Software	Internal Use Software In accordance with the authoritative guidance, the Company capitalizes external direct costs of materials and services and internal costs such as payroll and benefits of those employees directly associated with the development of new functionality in internal use software and software developed related to its Mobility Apps products. The amount of costs capitalized in 2015 and 2014 relating to internal use software was $93.9 million and $79.1 million , respectively. These costs are being amortized over the estimated useful life of the software, which is generally three to seven years, and are included in property and equipment in the accompanying consolidated balance sheets.
Revenue Recognition	Revenue Recognition Net revenues include the following categories: Product and licenses, SaaS, License updates and maintenance and Professional services. Product and licenses revenues primarily represent fees related to the licensing of the Company’s software and hardware appliances. These revenues are reflected net of sales allowances, cooperative advertising agreements, partner incentive programs and provisions for returns. SaaS revenues consist primarily of fees related to online service agreements, which are recognized ratably over the contract term, which is typically 12 months. In addition, SaaS revenues may also include set-up fees, which are recognized ratably over the contract term or the expected customer life, whichever is longer. License updates and maintenance revenues consist of fees related to the Subscription Advantage program and maintenance fees, which include technical support and hardware and software maintenance. Subscription Advantage is a renewable program that provides subscribers with immediate access to software upgrades, enhancements and maintenance releases when and if they become available during the term of the contract. Subscription Advantage and maintenance fees are recognized ratably over the term of the contract, which is typically 12 to 24 months. The Company capitalizes certain third-party commissions related to Subscription Advantage, maintenance and support renewals. The capitalized commissions are amortized to Sales, marketing and services expense at the time the related deferred revenue is recognized as revenue. Hardware and software maintenance and support contracts are typically sold separately. Hardware maintenance includes technical support, the latest software upgrades and replacement of malfunctioning appliances. Dedicated account management is available as an add-on to the program for a higher level of service. Software maintenance includes unlimited technical support, immediate access to software upgrades, enhancements and maintenance releases when and if they become available during the term of the contract. Professional services revenues are comprised of fees from consulting services related to the implementation of the Company’s products and fees from product training and certification, which are recognized as the services are provided. The Company recognizes revenue when it is earned and when all of the following criteria are met: persuasive evidence of the arrangement exists; delivery has occurred or the service has been provided and the Company has no remaining obligations; the fee is fixed or determinable; and collectability is probable. The Company defines these four criteria as follows: • Persuasive evidence of the arrangement exists. Evidence of an arrangement generally consists of a purchase order issued pursuant to the terms and conditions of a distributor, reseller or end user agreement. For SaaS, the Company generally requires the customer or the reseller to electronically accept the terms of an online services agreement or execute a contract. • Delivery has occurred and the Company has no remaining obligations. The Company considers delivery of licenses under electronic licensing agreements to have occurred when the related products are shipped and the end-user has been electronically provided the software activation keys that allow the end-user to take immediate possession of the product. For hardware appliance sales, the Company’s standard delivery method is free-on-board shipping point. Consequently, it considers delivery of appliances to have occurred when they are shipped pursuant to an agreement and purchase order. For SaaS, delivery occurs upon providing the users with their login id and password. For product training and consulting services, the Company fulfills its obligation when the services are performed. For license updates and maintenance, the Company assumes that its obligation is satisfied ratably over the respective terms of the agreements, which are typically 12 to 24 months. For SaaS, the Company assumes that its obligation is satisfied ratably over the respective terms of the agreements, which are typically 12 months. • The fee is fixed or determinable. In the normal course of business, the Company does not provide customers the right to a refund of any portion of their license fees or extended payment terms. The fees are considered fixed or determinable upon establishment of an arrangement that contains the final terms of the sale including description, quantity and price of each product or service purchased. For SaaS, the fee is considered fixed or determinable if it is not subject to refund or adjustment. • Collectability is probable. The Company assesses collectability based primarily on the creditworthiness of the customer. Management’s judgment is required in assessing the probability of collection, which is generally based on an evaluation of customer specific information, historical experience and economic market conditions. If the Company determines from the outset of an arrangement that collectability is not probable, revenue recognition is deferred until customer payment is received and the other parameters of revenue recognition described above have been achieved. The majority of the Company’s product and license revenue consists of revenue from the sale of software products. Software sales generally include a perpetual license to the Company’s software and is subject to the industry specific software revenue recognition guidance. In accordance with this guidance, the Company allocates revenue to license updates related to its stand-alone software and any other undelivered elements of the arrangement based on vendor specific objective evidence (“VSOE”) of fair value of each element and such amounts are deferred until the applicable delivery criteria and other revenue recognition criteria described above have been met. The balance of the revenues, net of any discounts inherent in the arrangement, is recognized at the outset of the arrangement using the residual method as the product licenses are delivered. If management cannot objectively determine the fair value of each undelivered element based on VSOE of fair value, revenue recognition is deferred until all elements are delivered, all services have been performed, or until fair value can be objectively determined. For hardware appliance and software transactions, the arrangement consideration is allocated to stand-alone software deliverables as a group and the non-software deliverables based on the relative selling prices using the selling price hierarchy in the revenue recognition guidance. The selling price hierarchy for a deliverable is based on its VSOE if available, third-party evidence of selling price ("TPE") if VSOE is not available, or estimated selling price ("ESP") if neither VSOE nor TPE is available. The Company then recognizes revenue on each deliverable in accordance with its policies for product and service revenue recognition. VSOE of selling price is based on the price charged when the element is sold separately. In determining VSOE, the Company requires that a substantial majority of the selling prices fall within a reasonable range based on historical discounting trends for specific products and services. TPE of selling price is established by evaluating competitor products or services in stand-alone sales to similarly situated customers. However, as the Company’s products contain a significant element of proprietary technology and its solutions offer substantially different features and functionality, the comparable pricing of products with similar functionality typically cannot be obtained. Additionally, as the Company is unable to reliably determine what competitors products’ selling prices are on a stand-alone basis, the Company is not typically able to determine TPE. The estimate of selling price is established considering multiple factors including, but not limited to, pricing practices in different geographies and through different sales channels and competitor pricing strategies. Our Citrix Service Provider ("CSP") program provides subscription-based services in which the CSP partners host software services to their end users. The fees from the CSP program are recognized based on usage and as the CSP services are provided to their end users. For the Company’s non-software transactions, it allocates the arrangement consideration based on the relative selling price of the deliverables. For the Company’s hardware appliances, it uses ESP as its selling price. For the Company’s support and services, it generally uses VSOE as its selling price. When the Company is unable to establish selling price using VSOE for its support and services, the Company uses ESP in its allocation of arrangement consideration. The Company’s Mobility Apps products are considered hosted service arrangements per the authoritative guidance, or SaaS. Generally, the Company’s Mobility Apps products are sold separately and not bundled with the Enterprise and Service Provider business unit’s products and services. In the normal course of business, the Company is not obligated to accept product returns from its distributors under any conditions, unless the product item is defective in manufacture. The Company establishes provisions for estimated returns, as well as other sales allowances, concurrently with the recognition of revenue. The provisions are established based upon consideration of a variety of factors, including, among other things, recent and historical return rates for both specific products and distributors and the impact of any new product releases and projected economic conditions. Product returns are provided for in the consolidated financial statements and have historically been within management’s expectations.
Product Concentration	Product Concentration The Company derives a substantial portion of its revenues from its Workspace Services solutions, which include its XenDesktop and XenApp products and related services, and anticipates that these products and future derivative products and product lines based upon this technology will continue to constitute a majority of its revenue. The Company has recently experienced declines in sales and could continue to experience declines in demand for its Workspace Services solutions and other products, whether as a result of general economic conditions, the delay or reduction in technology purchases, new competitive product releases, price competition, lack of success of its strategic partners, technological change or other factors.
Cost of Net Revenues	Cost of Net Revenues Cost of product and license revenues consists primarily of hardware, product media and duplication, manuals, packaging materials, shipping expense and server capacity costs. In addition, the Company is a party to licensing agreements with various entities, which give the Company the right to use certain software code in its products or in the development of future products in exchange for the payment of fixed fees or amounts based upon the sales of the related product. The licensing agreements generally have terms ranging from one to five years, and generally include renewal options. However, some agreements are perpetual unless expressly terminated. Royalties and other costs related to these agreements are included in cost of net revenues. Cost of services and maintenance revenue consists primarily of compensation and other personnel-related costs of providing technical support and consulting, as well as costs of hosting the Company’s Mobility Apps products. Also included in cost of net revenues is amortization and impairment of product related intangible assets which includes acquired core and product technology and associated patents.
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. Effective January 1, 2015, the functional currency of the Company’s wholly-owned foreign subsidiaries of its Mobility Apps business unit became the U.S. dollar as a result of a reorganization in the foreign subsidiaries' operations. Prior to January 1, 2015, the functional currency of the Company’s wholly-owned foreign subsidiaries of its Mobility Apps business unit was the currency of the country in which each subsidiary is located. The Company translated assets and liabilities of these foreign subsidiaries at exchange rates in effect at the balance sheet date and included accumulated net translation adjustments in equity as a component of Accumulated other comprehensive loss. The change in functional currency is applied on a prospective basis, therefore a ny gains and losses that were previously recorded in Accumulated other comprehensive loss remain unchanged from January 1, 2015. Foreign currency transaction gains and losses are the result of exchange rate changes on transactions denominated in currencies other than the functional currency, including U.S. dollars. The remeasurement of those foreign currency transactions is included in determining net income or loss for the period of exchange.
Derivatives and Hedging Activities	Derivatives and Hedging Activities In accordance with the authoritative guidance, the Company records derivatives at fair value as either assets or liabilities on the balance sheet. For derivatives that are designated as and qualify as effective cash flow hedges, the portion of gain or loss on the derivative instrument effective at offsetting changes in the hedged item is reported as a component of Accumulated other comprehensive loss and reclassified into earnings as operating expense, net, when the hedged transaction affects earnings. Derivatives not designated as hedging instruments are adjusted to fair value through earnings as Other expense, net, in the period during which changes in fair value occur. The application of the authoritative guidance could impact the volatility of earnings. The Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objective and strategy for undertaking various hedge transactions. This process includes attributing all derivatives that are designated as cash flow hedges to floating rate assets or liabilities or forecasted transactions. The Company also formally assesses, both at the inception of the hedge and on an ongoing basis, whether each derivative is highly effective in offsetting changes in cash flows of the hedged item. Fluctuations in the value of the derivative instruments are generally offset by changes in the hedged item; however, if it is determined that a derivative is not highly effective as a hedge or if a derivative ceases to be a highly effective hedge, the Company will discontinue hedge accounting prospectively for the affected derivative. The Company is exposed to risk of default by its hedging counterparties. Although this risk is concentrated among a limited number of counterparties, the Company’s foreign exchange hedging policy attempts to minimize this risk by placing limits on the amount of exposure that may exist with any single financial institution at a time.
Pension Liability	Pension Liability The Company provides retirement benefits to certain employees who are not U.S. based. Generally, benefits under these programs are based on an employee’s length of service and level of compensation. The majority of these programs are commonly referred to as termination indemnities, which provide retirement benefits in accordance with programs mandated by the governments of the countries in which such employees work.
Advertising Costs	Advertising Costs The Company expenses advertising costs as incurred. The Company has advertising agreements with, and purchases advertising from, online media providers to advertise its products. The Company also has cooperative advertising agreements with certain distributors and resellers whereby the Company will reimburse distributors and resellers for qualified advertising of Company products. Reimbursement is made once the distributor, reseller or provider provides substantiation of qualified expenses. The Company estimates the impact of these expenses and recognizes them at the time of product sales as a reduction of net revenue in the accompanying consolidated statements of income.
Income Taxes	Income Taxes The Company and one or more of its subsidiaries is subject to United States federal income taxes, as well as income taxes of multiple state and foreign jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal, state and local, or non-U.S. income tax examinations by tax authorities for years prior to 2012. In the ordinary course of global business, there are transactions for which the ultimate tax outcome is uncertain; thus, judgment is required in determining the worldwide provision for income taxes. The Company provides for income taxes on transactions based on its estimate of the probable liability. The Company adjusts its provision as appropriate for changes that impact its underlying judgments. Changes that impact provision estimates include such items as jurisdictional interpretations on tax filing positions based on the results of tax audits and general tax authority rulings. Due to the evolving nature of tax rules combined with the large number of jurisdictions in which the Company operates, estimates of its tax liability and the realizability of its deferred tax assets could change in the future, which may result in additional tax liabilities and adversely affect the Company’s results of operations, financial condition and cash flows. 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 consolidated financial statements. 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.
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 consolidated financial statements and accompanying notes. Significant estimates made by management include 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 fair value of convertible senior notes, the provision for lease losses, the provision for income taxes and the amortization and depreciation periods for intangible and long-lived assets. While the Company believes that such estimates are fair when considered in conjunction with the consolidated financial position and results of operations taken as a whole, the actual amounts of such items, when known, will vary from these estimates.
Accounting for Stock-Based Compensation	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 consolidated financial statements using a fair value method.
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 vesting or exercise of stock awards (calculated using the treasury stock method) during the period they were outstanding. Certain shares under the Company’s stock-based compensation programs were excluded from the computation of diluted earnings per share due to their anti-dilutive effect for the respective periods in which they were outstanding. Additionally, the computation of diluted earnings per share does not include the effect of the potential outstanding common stock from the Company's convertible senior notes and warrants because the effect would have been anti-dilutive.
Reclassifications	Reclassifications Certain reclassifications of the prior years' amounts have been made to conform to the current year's presentation.
New Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS In November 2015, the Financial Accounting Standards Board issued an accounting standard update on income taxes. The new authoritative guidance requires deferred tax liabilities and assets, along with any related valuation allowance, to be classified as noncurrent on the consolidated balance sheet. This standard is required to be adopted for annual periods beginning after December 15, 2016, including interim periods within that annual period, with early adoption permitted. The amendment may be applied either prospectively to all deferred tax liabilities and assets or retrospectively to all periods presented. The Company elected to prospectively adopt the accounting standard in the beginning of the fourth quarter of 2015. Prior periods in the Company's Consolidated Financial Statements were not retrospectively adjusted. In September 2015, the Financial Accounting Standards Board issued an accounting standard update on business combinations. The new guidance requires that an acquirer in a business combination recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined, including the cumulative effect of the change in provisional amount as if the accounting had been completed as of the acquisition date. The adjustments related to previous reporting periods since the acquisition date must be disclosed by income statement line item either on the face of the income statement or in the notes. The guidance becomes effective for fiscal years and interim reporting periods beginning on or after December 15, 2015, with early adoption permitted. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial position, results of operations and cash flows. In April 2015, the Financial Accounting Standards Board issued an accounting standard update on the presentation of debt issuance costs. The new guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The guidance becomes effective for fiscal years and interim reporting periods beginning on or after December 15, 2015, with early adoption permitted. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial position, results of operations and cash flows. In May 2014, the Financial Accounting Standards Board issued an accounting standard update on revenue recognition. The new guidance creates a single, principle-based model for revenue recognition and expands and improves disclosures about revenue. In July 2015, the Financial Accounting Standards Board issued an accounting standard update that defers the effective date of the new revenue recognition standard by one year. The new guidance is effective for annual reporting periods beginning on or after December 15, 2017, and must be adopted using either a full retrospective approach for all periods presented in the period of adoption or a modified retrospective approach. The Company has initiated an assessment of its systems, data and processes related to the implementation of this accounting standard, which is expected to be completed during 2016. The Company is currently evaluating the potential impact of this standard on its financial position and results of operations.

Significant Accounting Polici29

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Schedule of Property and Equipment	Property and equipment consist of the following: December 31, 2015 2014 (In thousands) Buildings $ 85,092 $ 85,092 Computer equipment 271,461 237,709 Software 487,191 392,009 Equipment and furniture 123,649 117,555 Leasehold improvements 217,200 211,625 1,184,593 1,043,990 Less accumulated depreciation and amortization (852,460 ) (722,691 ) Assets under construction 14,097 18,893 Land 27,587 27,587 Total $ 373,817 $ 367,779
Schedule of Changes in Goodwill	The following table presents the change in goodwill allocated to the Company’s reportable segments during 2015 and 2014 (in thousands): Balance at January 1, 2015 Additions Other Balance at December 31, 2015 Balance at January 1, 2014 Additions Other Balance at December 31, 2014 Enterprise and Service Provider $ 1,434,369 $ 61,641 $ (740 ) (2) $ 1,495,270 $ 1,402,156 $ 30,317 $ 1,896 (4) $ 1,434,369 Mobility Apps 362,482 104,970 — 467,452 366,793 10,694 (15,005 ) (3) 362,482 Consolidated $ 1,796,851 $ 166,611 (1) $ (740 ) $ 1,962,722 $ 1,768,949 $ 41,011 (1) $ (13,109 ) $ 1,796,851 (1) Amount primarily relates to 2015 acquisitions. See Note 3 for more information regarding the Company’s acquisitions. (2) Amount primarily relates to adjustments to purchase price allocations for certain 2014 Acquisitions. (3) Amount primarily relates to foreign currency translation. Refer to Foreign Currency discussion below for additional information. (4) Amount primarily relates to adjustments to purchase price allocations for certain 2013 Acquisitions.
Schedule of Intangible Assets	Intangible assets consist of the following (in thousands): December 31, 2015 Gross Carrying Amount Accumulated Amortization Weighted-Average Life (Years) Product related intangible assets $ 589,847 $ 476,141 5.67 Other 447,816 278,104 6.48 Total $ 1,037,663 $ 754,245 6.27 December 31, 2014 Gross Carrying Amount Accumulated Amortization Weighted-Average Life (Years) Product related intangible assets $ 618,336 $ 454,830 5.58 Other 492,960 265,749 7.58 Total $ 1,111,296 $ 720,579 6.47
Schedule of Estimated Future Annual Amortization Expense of Intangible Assets	Estimated future amortization expense of intangible assets with finite lives as of December 31, 2015 is as follows (in thousands): Year ending December 31, 2016 $ 81,687 2017 60,013 2018 52,003 2019 36,047 2020 21,792 Thereafter 31,876 Total $ 283,418

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Schedule of Allocation of Purchase Price	The allocation of the total purchase prices is summarized below (in thousands): Sanbolic Grasshopper Other 2015 Acquisition Purchase Price Allocation Asset Life Purchase Price Allocation Asset Life Purchase Price Allocation Asset Life Current assets $ 581 $ 4,818 $ 205 Property and equipment — 467 Various — Intangible assets 45,300 Various 71,400 Various 980 5 years Goodwill 61,641 Indefinite 99,686 Indefinite 5,285 Indefinite Other assets — 80 — Assets acquired 107,522 176,451 6,470 Current liabilities assumed 1,454 11,181 42 Long-term liabilities assumed 3,175 158 — Deferred tax liabilities, non-current 13,297 — 306 Net assets acquired $ 89,596 $ 165,112 $ 6,122
Schedule of Intangible Assets Acquired	Identifiable intangible assets acquired in connection with the 2015 Acquisitions (in thousands) and the weighted-average lives are as follows: Sanbolic Asset Life Grasshopper Asset Life Other 2015 Acquisition Asset Life Core and product technologies $ 43,800 5 and 6 years $ 25,000 7 years $ 980 5 years Customer relationships 1,500 2 years 37,900 5 years — Telecommunication carrier relationships — 7,900 2 years — Tradename — 600 2 years — Total $ 45,300 $ 71,400 $ 980
Schedule of Pro Forma Information	The following unaudited pro-forma information combines the consolidated results of the operations of the Company and the 2015 Acquisitions as if the acquisitions had occurred on January 1, 2014, the first day of the Company's fiscal year 2014 (in thousands, except per share data): Twelve Months Ended December 31, 2015 2014 Revenues $ 3,289,264 $ 3,170,128 Income from operations 349,577 276,344 Net income 318,794 234,957 Per share - basic 2.01 1.38 Per share - diluted 1.99 1.37

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Schedule Of Available-For-Sale Securities	Investments in available-for-sale securities at fair value were as follows for the periods ended (in thousands): December 31, 2015 December 31, 2014 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 $ 530,981 $ 757 $ (1,216 ) $ 530,522 $ 637,474 $ 1,296 $ (457 ) $ 638,313 Corporate securities 699,210 90 (1,929 ) 697,371 795,255 232 (1,372 ) 794,115 Municipal securities 14,872 14 (8 ) 14,878 48,744 17 (31 ) 48,730 Government securities 152,376 9 (340 ) 152,045 121,431 37 (256 ) 121,212 Total $ 1,397,439 $ 870 $ (3,493 ) $ 1,394,816 $ 1,602,904 $ 1,582 $ (2,116 ) $ 1,602,370

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
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 December 31, 2015 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 $ 261,962 $ 261,962 $ — $ — Money market funds 102,968 102,968 — — Corporate securities 3,588 — 3,588 — Available-for-sale securities: Agency securities 530,522 — 530,522 — Corporate securities 697,371 — 695,809 1,562 Municipal securities 14,878 — 14,878 — Government securities 152,045 — 152,045 — Prepaid expenses and other current assets: Foreign currency derivatives 1,063 — 1,063 — Total assets $ 1,764,397 $ 364,930 $ 1,397,905 $ 1,562 Accrued expenses and other current liabilities: Foreign currency derivatives 3,678 — 3,678 — Total liabilities $ 3,678 $ — $ 3,678 $ — As of December 31, 2014 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 $ 230,370 $ 230,370 $ — $ — Money market funds 29,512 29,512 — — Corporate securities 267 — 267 — Available-for-sale securities: Agency securities 638,313 — 638,313 — Corporate securities 794,115 — 788,042 6,073 Municipal securities 48,730 — 48,730 — Government securities 121,212 — 121,212 — Prepaid expenses and other current assets: Foreign currency derivatives 1,206 — 1,206 — Total assets $ 1,863,725 $ 259,882 $ 1,597,770 $ 6,073 Accrued expenses and other current liabilities: Foreign currency derivatives 9,692 — 9,692 — Total liabilities $ 9,692 $ — $ 9,692 $ —
Assets Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs	This methodology required the Company to make assumptions that were not directly or indirectly observable regarding the fair value of the convertible debt securities; accordingly they are a Level 3 valuation and included in the table below. Investments (in thousands) Balance at December 31, 2014 $ 6,073 Purchases of Level 3 securities 1,775 Proceeds received on Level 3 securities (501 ) Total net realized losses included in earnings (838 ) Transfers out of Level 3 (4,947 ) Balance at December 31, 2015 $ 1,562
Fair Value, by Balance Sheet Grouping	As of December 31, 2015 , the fair value of the Convertible 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 year ended December 31, 2015 , and carrying value of debt instruments (carrying value excludes the equity component of the Company’s Convertible Notes classified in equity) was as follows (in thousands): Fair Value Carrying Value Convertible Senior Notes $ 1,567,364 $ 1,324,992

Accrued Expenses and Other Cu33

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Accounts Payable and Accrued Liabilities, Current [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses consist of the following: December 31, 2015 2014 (In thousands) Accrued compensation and employee benefits $ 184,286 $ 158,142 Other accrued expenses 133,182 139,937 Total $ 317,468 $ 298,079

Employee Stock-Based Compensa34

Employee Stock-Based Compensation and Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Assumptions Used To Value Option Grants	The Company used the Black-Scholes model to estimate the fair value of its Employee Stock Purchase Plan awards with the following weighted-average assumptions: Year Ended December 31, 2015 Expected volatility factor 0.35 Risk free interest rate 0.25 % Expected dividend yield 0 % Expected life (in years) 0.5
Detail Of The 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): Income Statement Classifications 2015 2014 2013 Cost of services and maintenance revenues $ 2,940 $ 2,560 $ 2,540 Research and development 47,723 55,560 63,448 Sales, marketing and services 49,315 61,925 65,549 General and administrative 47,390 49,242 52,404 Total $ 147,368 $ 169,287 $ 183,941
Schedule of Nonvested Stock Unit Activity	The following table summarizes the Company's non-vested stock unit activity for the year ended December 31, 2015 : Number of Shares Weighted- Average Fair Value at Grant Date Non-vested stock units at December 31, 2014 5,037,295 $ 66.20 Granted 3,415,207 66.70 Assumed from acquisitions 142,822 64.78 Vested (1,971,312 ) 64.10 Forfeited (1,476,086 ) 69.38 Non-vested stock units at December 31, 2015 5,147,926 65.00
Schedule of Stock Option Activity	A summary of the status and activity of the Company’s fixed option awards is as follows: Options Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2014 3,577,549 $ 67.60 1.29 Exercised (1,875,339 ) 59.87 Forfeited or expired (390,098 ) 77.36 Outstanding at December 31, 2015 1,312,112 75.72 0.58 $ 5,978 Vested or expected to vest 1,311,936 75.73 0.58 $ 5,977 Exercisable at December 31, 2015 1,307,487 75.82 0.57 $ 5,857
Employee stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Assumptions Used To Value Option Grants	The assumptions used to value options granted and/or assumed are as follows: Stock options granted or assumed during 2013 Expected volatility factor 0.39 Approximate risk free interest rate 0.4% Expected term (in years) 3.35 Expected dividend yield 0%
Non-vested stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Assumptions Used To Value Option 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 2015 Grant March 2014 Grant March 2013 Grant Expected volatility factor 0.14 - 0.29 0.19 - 0.38 0.16 - 0.42 Risk free interest rate 0.85 % 0.81 % 0.33 % Expected dividend yield 0 % 0 % 0 %

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Lease Commitments	Lease commitments under non-cancelable operating leases with initial or remaining terms in excess of one year and sublease income associated with non-cancelable subleases, are as follows: Operating Leases Sublease Income (In thousands) Years ending December 31, 2016 $ 64,539 $ 272 2017 52,243 218 2018 46,199 204 2019 43,119 — 2020 35,363 — Thereafter 153,139 — Total $ 394,602 $ 694

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
United States and Foreign Components of Income Before Income Taxes	The United States and foreign components of income before income taxes are as follows: 2015 2014 2013 (In thousands) United States $ (3,332 ) $ 82,032 $ 142,085 Foreign 315,209 193,674 245,805 Total $ 311,877 $ 275,706 $ 387,890
Components of the Provision for Income Taxes	The components of the provision for income taxes are as follows: 2015 2014 2013 (In thousands) Current: Federal $ 27,860 $ 22,377 $ 51,389 Foreign 43,796 30,878 37,221 State 10,238 7,710 11,605 Total current 81,894 60,965 100,215 Deferred: Federal (75,479 ) (26,922 ) (34,897 ) Foreign (2,746 ) (1,023 ) (8,413 ) State (11,153 ) (9,037 ) (8,538 ) Total deferred (89,378 ) (36,982 ) (51,848 ) Total provision $ (7,484 ) $ 23,983 $ 48,367
Components of Deferred Tax Assets and Liabilities	The following table presents the breakdown between current and non-current net deferred tax assets: December 31, 2015 2014 (In thousands) Deferred tax assets - current (1) $ — $ 45,892 Deferred tax liabilities - current (1) — (1,053 ) Deferred tax assets- non current 215,196 128,198 Deferred tax liabilities - non current (3,903 ) (8,722 ) Total net deferred tax assets $ 211,293 $ 164,315 (1) During the year ended December 31, 2015, the Company elected to early adopt an accounting standard update on income taxes on a prospective basis. The new authoritative guidance requires deferred tax liabilities and assets along with any related valuation allowance to be classified as noncurrent on the consolidated balance sheet. The December 31, 2014 consolidated balance sheet was not retrospectively adjusted. The significant components of the Company’s deferred tax assets and liabilities consisted of the following: December 31, 2015 2014 (In thousands) Deferred tax assets: Accruals and reserves $ 36,628 $ 27,105 Deferred revenue 84,631 65,541 Tax credits 41,444 43,211 Net operating losses 50,466 75,318 Other 7,527 12,878 Stock based compensation 46,582 63,993 Valuation allowance (16,673 ) (15,167 ) Total deferred tax assets 250,605 272,879 Deferred tax liabilities: Depreciation and amortization (16,113 ) (16,835 ) Acquired technology (15,825 ) (82,357 ) Prepaid expenses (7,374 ) (9,372 ) Total deferred tax liabilities (39,312 ) (108,564 ) Total net deferred tax assets $ 211,293 $ 164,315
Reconciliation of The Company's Effective Tax Rate to The Statutory Federal Rate	A reconciliation of the Company’s effective tax rate to the statutory federal rate is as follows: Year Ended December 31, 2015 2014 2013 Federal statutory taxes 35.0 % 35.0 % 35.0 % State income taxes, net of federal tax benefit 0.9 1.2 1.2 Foreign operations (22.3 ) (13.8 ) (14.8 ) Permanent differences 6.1 3.3 (1.1 ) Change in deferred tax liability related to acquired intangibles (6.6 ) (5.9 ) — Tax credits (13.4 ) (13.7 ) (10.9 ) Stock option compensation 0.5 1.9 0.4 Change in accruals for uncertain tax positions (3.2 ) (0.3 ) 3.3 Other 0.6 1.0 (0.6 ) (2.4 )% 8.7 % 12.5 %
Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, 2015 and 2014 is as follows (in thousands): Balance at January 1, 2014 $ 63,792 Additions based on tax positions related to the current year 5,711 Additions for tax positions of prior years 12,998 Reductions related to the expiration of statutes of limitations (4,118 ) Settlements (11,465 ) Balance at December 31, 2014 66,918 Additions based on tax positions related to the current year 6,613 Additions for tax positions of prior years 4,675 Reductions related to the expiration of statutes of limitations (9,521 ) Settlements (14,064 ) Balance at December 31, 2015 $ 54,621

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Net Revenues And Profit By Segment	Net revenues and segment profit for 2015 , 2014 and 2013 classified by the Company’s reportable segments, are presented below: 2015 2014 2013 (In thousands) Net revenues: Enterprise and Service Provider $ 2,544,302 $ 2,491,294 $ 2,335,562 Mobility Apps 731,292 651,562 582,872 Consolidated $ 3,275,594 $ 3,142,856 $ 2,918,434 Segment profit (1) : Enterprise and Services Provider $ 759,614 $ 589,076 $ 588,138 Mobility Apps 83,535 115,998 116,061 Unallocated expenses (2) : Amortization and impairment of intangible assets (239,915 ) (192,325 ) (139,541 ) Patent litigation charge — (20,727 ) — Other 982 — — Restructuring (100,411 ) (20,424 ) — Net interest and other (expense) income, net (38,208 ) (26,605 ) 7,173 Stock-based compensation (147,368 ) (169,287 ) (183,941 ) Separation costs (6,352 ) — — Consolidated income before income taxes $ 311,877 $ 275,706 $ 387,890 (1) Effective January 1, 2015, the Company revised its methodology for allocating certain corporate costs within General and administrative expenses to more closely align these costs to the employees directly utilizing the related services within each of its reporting segments in connection with organizational structure changes that changed the manner in which shared support services are provided. This change in presentation does not affect the Company's consolidated financial position, results from operations or cash flows. (2) Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments
Identifiable Assets By Segment	Identifiable assets classified by the Company’s reportable segments are shown below. Long-lived assets consist of property and equipment, net, and are shown below. December 31, 2015 2014 (In thousands) Identifiable assets: Enterprise and Service Provider $ 4,578,436 $ 4,879,513 Mobility Apps 903,002 632,494 Total identifiable assets $ 5,481,438 $ 5,512,007
Identifiable and Long-Lived Assets by Product Grouping and Countries	December 31, 2015 2014 (In thousands) Property and equipment, net: United States $ 294,982 $ 284,463 United Kingdom 28,851 29,556 Other countries 49,984 53,760 Total property and equipment, net $ 373,817 $ 367,779
Revenues By Product Grouping	Revenues by product grouping for the Company’s Enterprise and Service Provider and Mobility Apps business units were as follows for the years ended: December 31, 2015 2014 2013 (In thousands) Net revenues: Enterprise and Service Provider Workspace Services revenues (1) $ 1,645,331 $ 1,606,903 $ 1,549,383 Delivery Networking revenues (2) 741,121 695,734 634,598 Professional services (3) 147,488 175,541 138,879 Other 10,362 13,116 12,702 Total Enterprise and Service Provider revenues 2,544,302 2,491,294 2,335,562 Mobility Apps revenues 731,292 651,562 582,872 Total net revenues $ 3,275,594 $ 3,142,856 $ 2,918,434 (1) Workspace Services revenues are primarily comprised of sales from the Company’s windows app delivery products, which includes XenDesktop and XenApp, and the Company's mobile app delivery products, which include XenMobile and related license updates and maintenance and support. (2) Delivery Networking revenues primarily include NetScaler, ByteMobile Smart Capacity and CloudBridge products and related license updates and maintenance and support. (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 segment and geographic location, for the years ended: December 31, 2015 2014 2013 (In thousands) Net revenues: Enterprise and Service Provider Americas $ 1,394,985 $ 1,328,851 $ 1,263,673 EMEA 866,775 859,404 785,862 Asia-Pacific 282,542 303,039 286,027 Total Enterprise and Service Provider revenues 2,544,302 2,491,294 2,335,562 Mobility Apps Americas 616,900 541,145 488,307 EMEA 91,324 87,705 73,529 Asia-Pacific 23,068 22,712 21,036 Total Mobility Apps revenues 731,292 651,562 582,872 Total net revenues $ 3,275,594 $ 3,142,856 $ 2,918,434

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Convertible Debt	The Convertible Notes consist of the following (in thousands): December 31, 2015 Liability component Principal $ 1,437,500 Less: note discount (112,508 ) Net carrying amount 1,324,992 Equity component * $ 162,869 * Recorded in the consolidated balance sheet within additional paid-in capital.
Schedule of Interest Expense Recognized Related to Convertible Notes	The following table includes total interest expense recognized related to the Convertible Notes (in thousands): Year Ended December 31, 2015 2014 Contractual interest expense $ 7,188 $ 4,792 Amortization of debt issuance costs 3,974 2,461 Amortization of debt discount 32,039 20,832 $ 43,201 $ 28,085

Derivative Financial Instrume39

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
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) December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 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 $436 Prepaid expenses and other current assets $435 Accrued expenses and other current liabilities $2,895 Accrued expenses and other current liabilities $9,364 Asset Derivatives Liability Derivatives (In thousands) December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 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 $627 Prepaid expenses and other current assets $771 Accrued expenses and other current liabilities $783 Accrued expenses and other current liabilities $328
Schedule of Effect of Derivative Instruments on Financial Performance	The Effect of Derivative Instruments on Financial Performance For the Year ended December 31, (In thousands) Derivatives in Cash Flow Hedging Relationships Amount of Gain (Loss) Recognized in Other Location of (Loss) Gain Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion) Amount of (Loss) Gain Reclassified from 2015 2014 2015 2014 Foreign currency forward contracts $ 6,090 $ (11,197 ) Operating expenses $ (13,027 ) $ 2,123 For the Year ended December 31, (In thousands) Derivatives Not Designated as Hedging Instruments Location of Gain Recognized in Income on Derivative Amount of Gain Recognized in Income on Derivative 2015 2014 Foreign currency forward contracts Other expense, net $ 1,669 $ 3,551
Currency Forward Contracts Outstanding	As of December 31, 2015 , the Company had the following net notional foreign currency forward contracts outstanding (in thousands): Foreign Currency Currency Denomination Australian dollars AUD 1,433 Brazilian Real BRL 5,700 British pounds sterling GBP 21,510 Canadian dollars CAD 4,700 Chinese renminbi CNY 35,000 Danish krone DKK 19,000 Euro EUR 1,500 Hong Kong dollars HKD 50,813 Indian rupees INR 660,475 Japanese yen JPY 449,015 Singapore dollars SGD 11,629 Swiss francs CHF 20,400

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
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): Year Ended December 31, 2015 2014 2013 Numerator: Net income $ 319,361 $ 251,723 $ 339,523 Denominator: Denominator for basic earnings per share - weighted-average shares outstanding 158,874 169,879 186,672 Effect of dilutive employee stock awards: Employee stock awards 1,488 1,391 1,573 Denominator for diluted earnings per share - weighted-average shares outstanding 160,362 171,270 188,245 Basic earnings per share $ 2.01 $ 1.48 $ 1.82 Diluted earnings per share $ 1.99 $ 1.47 $ 1.80 Anti-dilutive weighted-average shares 2,151 3,026 3,647

Comprehensive Income (Tables)

Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2015
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 (in thousands): Foreign currency Unrealized gain (loss) on available-for-sale securities Unrealized gain (loss) on derivative instruments Other comprehensive loss on pension liability Total (In thousands) Balance at December 31, 2014 $ (16,346 ) $ (990 ) $ (8,345 ) $ (11,109 ) $ (36,790 ) Other comprehensive income (loss) before reclassifications — (2,080 ) (6,937 ) 4,083 (4,934 ) Amounts reclassified from Accumulated other comprehensive loss — 170 13,027 — 13,197 Net current period other comprehensive income (loss) — (1,910 ) 6,090 4,083 8,263 Balance at December 31, 2015 $ (16,346 ) $ (2,900 ) $ (2,255 ) $ (7,026 ) $ (28,527 )
Schedule of Reclassification out of Accumulated Other Comprehensive Income	Reclassifications out of Accumulated other comprehensive loss are as follows (in thousands): For the Twelve Months Ended December 31, 2015 (In thousands) Details about Accumulated other comprehensive loss components Amount reclassified from Accumulated other comprehensive loss, net of tax Affected line item in the Consolidated Statements of Income Unrealized net loss on available-for-sale securities $ 170 Other expense, net Unrealized net loss on cash flow hedges 13,027 Operating expenses * $ 13,197 * Operating expenses amounts allocated to Research and development, Sales, marketing and services, and General and administrative are not individually significant.

Restructuring (Tables)

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Charges by Segment	Restructuring charges related to the reduction of the Company's headcount by segment consists of the following (in thousands): Year ended Year ended December 31, 2015 December 31, 2014 2014 Restructuring Program Enterprise and Service Provider $ 1,724 $ 14,092 Mobility Apps 50 6,332 2015 Restructuring Program Enterprise and Service Provider 67,548 — Mobility Apps 1,357 — 2015 Other Restructuring Program Enterprise and Service Provider 27,680 — Mobility Apps 2,052 — Total restructuring charges $ 100,411 $ 20,424
Schedule of Restructuring Reserve	The activity in the Company’s restructuring accruals for the year ended December 31, 2015 is summarized as follows (in thousands): 2014 Restructuring Program 2015 Restructuring Program 2015 Other Restructuring Program Total Balance at January 1, 2015 $ 2,780 $ — $ — $ 2,780 Employee severance and related costs 2,060 44,837 29,732 76,629 Consolidation of leased facilities — 22,100 — 22,100 Payments (3,433 ) (44,243 ) (13,151 ) (60,827 ) Reversal of previous charges (286 ) — — (286 ) Balance at December 31, 2015 $ 1,121 $ 22,694 $ 16,581 $ 40,396

Quarterly Financial Informati43

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Data [Abstract]
Schedule of quarterly financial information (unaudited)	First Quarter Second Quarter Third Quarter Fourth Quarter Total Year (In thousands, except per share amounts) 2015 Net revenues $ 760,802 $ 796,759 $ 813,270 $ 904,763 $ 3,275,594 Gross margin 628,196 664,008 667,016 702,010 2,661,230 Income from operations 51,732 122,149 63,798 112,406 350,085 Net income 28,887 103,275 55,925 131,274 319,361 Earnings per share - basic 0.18 0.64 0.35 0.85 2.01 Earnings per share - diluted 0.18 0.64 0.35 0.84 1.99 First Quarter Second Quarter Third Quarter Fourth Quarter Total Year (In thousands, except per share amounts) 2014 Net revenues $ 750,819 $ 781,560 $ 758,994 $ 851,483 $ 3,142,856 Gross margin 616,493 606,304 623,009 676,831 2,522,637 Income from operations 71,887 54,419 58,597 117,408 302,311 Net income 55,939 53,024 47,532 95,228 251,723 Earnings per share - basic 0.30 0.31 0.29 0.59 1.48 Earnings per share - diluted 0.30 0.31 0.29 0.58 1.47

Significant Accounting Polici44

Significant Accounting Policies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)customer	Dec. 31, 2014USD ($)customer	Dec. 31, 2013USD ($)
Significant Accounting Policies [Line Items]
Allowance for doubtful accounts	$ 6.3	$ 3.8
Estimated useful lives of intangible assets	6 years 3 months 7 days	6 years 5 months 20 days
Amount capitalized related to internal use software	$ 93.9	$ 79.1
Amount expensed related to internal use software	81.8	66.8	$ 58.6
Allowance for estimated product returns	1.4	2.2
Advertising costs	144.1	150.1	146.5
Foreign postretirement benefit plans
Significant Accounting Policies [Line Items]
Termination indemnities	13.8	15.6
Termination indemnities, compensation expense	$ 3.8	$ 3.2	$ 3.5
Online service agreements
Significant Accounting Policies [Line Items]
Revenue recognition, period for recognition	12 months
Minimum
Significant Accounting Policies [Line Items]
Estimated useful lives of intangible assets	3 years
Licensing agreement term	1 year
Minimum | License update
Significant Accounting Policies [Line Items]
Revenue recognition, period for recognition	12 months
Maximum
Significant Accounting Policies [Line Items]
Estimated useful lives of intangible assets	7 years
Licensing agreement term	5 years
Maximum | License update
Significant Accounting Policies [Line Items]
Revenue recognition, period for recognition	24 months
Weighted average | Online service agreements
Significant Accounting Policies [Line Items]
Revenue recognition, period for recognition	12 months
Customer concentration risk | Accounts receivable
Significant Accounting Policies [Line Items]
Number of customers meeting concentration risk threshold | customer	0	2
Customer concentration risk | Accounts receivable | Arrow Group
Significant Accounting Policies [Line Items]
Concentration risk percentage		11.00%
Customer concentration risk | Accounts receivable | Ingram Micro
Significant Accounting Policies [Line Items]
Concentration risk percentage		10.00%

Significant Accounting Polici45

Significant Accounting Policies (Property and Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Retirement of property and equipment	$ 25,800	$ 11,400
Property and equipment, gross	1,184,593	1,043,990
Less accumulated depreciation and amortization	(852,460)	(722,691)
Total property and equipment, net	$ 373,817	367,779
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful lives of property and equipment	40 years
Property and equipment, gross	$ 85,092	85,092
Computer equipment
Property, Plant and Equipment [Line Items]
Estimated useful lives of property and equipment	3 years
Property and equipment, gross	$ 271,461	237,709
Software
Property, Plant and Equipment [Line Items]
Estimated useful lives of property and equipment	3 years
Property and equipment, gross	$ 487,191	392,009
Equipment and furniture
Property, Plant and Equipment [Line Items]
Estimated useful lives of property and equipment	7 years
Property and equipment, gross	$ 123,649	117,555
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 217,200	211,625
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of property and equipment	10 years
Assets under construction
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 14,097	18,893
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27,587	27,587
Enterprise and Service Provider
Property, Plant and Equipment [Line Items]
Asset Impairment Charges	$ 123,000	$ 59,300

Significant Accounting Polici46

Significant Accounting Policies (Changes in Goodwill) (Details) - USD ($)		3 Months Ended		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015		Dec. 31, 2014
Goodwill [Line Items]
Goodwill and intangible asset impairment		$ 0	$ 0
Goodwill [Roll Forward]
Beginning balance				$ 1,796,851,000		$ 1,768,949,000
Additions	[1]			166,611,000		41,011,000
Other				(740,000)		(13,109,000)
Ending balance		1,962,722,000	1,796,851,000	1,962,722,000		1,796,851,000
Enterprise and Service Provider
Goodwill [Roll Forward]
Beginning balance				1,434,369,000		1,402,156,000
Additions				61,641,000		30,317,000
Other				(740,000)	[2]	1,896,000	[3]
Ending balance		1,495,270,000	1,434,369,000	1,495,270,000		1,434,369,000
Mobility Apps division
Goodwill [Roll Forward]
Beginning balance				362,482,000		366,793,000
Additions				104,970,000		10,694,000
Other	[4]			0		(15,005,000)
Ending balance		$ 467,452,000	$ 362,482,000	$ 467,452,000		$ 362,482,000
[1]	Amount primarily relates to 2015 acquisitions. See Note 3 for more information regarding the Company’s acquisitions.
[2]	Amount primarily relates to adjustments to purchase price allocations for certain 2014 Acquisitions.
[3]	Amount primarily relates to adjustments to purchase price allocations for certain 2013 Acquisitions.
[4]	Amount primarily relates to foreign currency translation. Refer to Foreign Currency discussion below for additional information.

Significant Accounting Polici47

Significant Accounting Policies (Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,037,663	$ 1,111,296
Accumulated Amortization	$ 754,245	$ 720,579
Weighted-Average Life (Years)	6 years 3 months 7 days	6 years 5 months 20 days
Finite-Lived Intangible Assets, Net	$ 283,418
Product related intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	589,847	$ 618,336
Accumulated Amortization	$ 476,141	$ 454,830
Weighted-Average Life (Years)	5 years 7 months 31 days	5 years 6 months 29 days
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 447,816	$ 492,960
Accumulated Amortization	$ 278,104	$ 265,749
Weighted-Average Life (Years)	6 years 5 months 22 days	7 years 6 months 28 days
Patents
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life (Years)	10 years
Minimum
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life (Years)	3 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Life (Years)	7 years
Cost of net revenues [Member] | Product related intangible assets
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 131,200	$ 146,400
Operating expenses | Other
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	108,800	$ 45,900
Enterprise and Service Provider | ByteMobile [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Finite-lived	123,000
Enterprise and Service Provider | Amortization and Impairment of Other Intangible Assets [Member] | ByteMobile [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Finite-lived	67,100
Enterprise and Service Provider | Amortization of Product Related Intangibles [Member] | ByteMobile [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Finite-lived	55,900
Estimate of Fair Value Measurement | Enterprise and Service Provider | ByteMobile [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	$ 26,800

Significant Accounting Polici48

Significant Accounting Policies (Estimated Future Annual Amortization Expense of Intangible Assets) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2,016	$ 81,687
2,017	60,013
2,018	52,003
2,019	36,047
2,020	21,792
Thereafter	31,876
Total	$ 283,418

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) - USD ($) $ in Thousands	Jan. 08, 2016	May. 18, 2015	Jan. 08, 2015	Oct. 31, 2014	Jan. 31, 2014	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2015
Sanbolic, Inc. [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions			$ 89,400
Cash acquired from the acquisition			200
Acquisition transaction costs			$ 500
Stock options converted and assumed (in shares)			37,057
Finite-lived Intangible assets acquired			$ 45,300
Grasshopper Group, LLC [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions		$ 161,500
Cash acquired from the acquisition		$ 3,600
Stock options converted and assumed (in shares)		105,765
Finite-lived Intangible assets acquired		$ 71,400
Other 2015 Acquisition [Member]
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired								$ 980
Framehawk, Inc. [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions					$ 24,200
Cash acquired from the acquisition					$ 200
Acquisition transaction costs						$ 100
RightSignature, LLC [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions				$ 37,800
Cash acquired from the acquisition				$ 1,100
Acquisition transaction costs						200
Stock options converted and assumed (in shares)				67,500
Other 2014 Acquisition [Member]
Business Acquisition [Line Items]
Total consideration in business acquisitions						19,900	$ 17,200
Cash acquired from the acquisition						$ 200	$ 800
Stock options converted and assumed (in shares)						23,430
General and administrative | Sanbolic, Inc. [Member]
Business Acquisition [Line Items]
Acquisition related costs								300
General and administrative | Grasshopper Group, LLC [Member]
Business Acquisition [Line Items]
Acquisition related costs								$ 300
General and administrative | Other 2014 Acquisition [Member]
Business Acquisition [Line Items]
Acquisition transaction costs						$ 100
Subsequent Event [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 23,600
Outsourced development and maintenance agreement, term of contract	3 years

Acquisitions (Allocation of Tot

Acquisitions (Allocation of Total Purchase Prices) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	May. 18, 2015	Jan. 08, 2015	Dec. 31, 2014	Dec. 31, 2013
Purchase Price Allocation
Goodwill	$ 1,962,722			$ 1,796,851	$ 1,768,949
Sanbolic, Inc. [Member]
Purchase Price Allocation
Current assets			$ 581
Property and equipment			0
Intangible assets			45,300
Goodwill			61,641
Other assets			0
Assets acquired			107,522
Current liabilities assumed			1,454
Long-term liabilities assumed			3,175
Deferred tax liabilities, non-current			13,297
Net assets acquired			$ 89,596
Grasshopper Group, LLC [Member]
Purchase Price Allocation
Current assets		$ 4,818
Property and equipment		467
Intangible assets		71,400
Goodwill		99,686
Other assets		80
Assets acquired		176,451
Current liabilities assumed		11,181
Long-term liabilities assumed		158
Deferred tax liabilities, non-current		0
Net assets acquired		$ 165,112
Other 2015 Acquisition [Member]
Purchase Price Allocation
Current assets	205
Property and equipment	0
Intangible assets	980
Goodwill	5,285
Other assets	0
Assets acquired	6,470
Current liabilities assumed	42
Long-term liabilities assumed	0
Deferred tax liabilities, non-current	306
Net assets acquired	$ 6,122
Finite-lived intangible assets acquired, Asset Life	5 years
Core and product technologies | Sanbolic, Inc. [Member]
Purchase Price Allocation
Intangible assets	$ 43,800
Core and product technologies | Sanbolic, Inc. [Member] | Minimum
Purchase Price Allocation
Finite-lived intangible assets acquired, Asset Life	5 years
Core and product technologies | Sanbolic, Inc. [Member] | Maximum
Purchase Price Allocation
Finite-lived intangible assets acquired, Asset Life	6 years
Core and product technologies | Grasshopper Group, LLC [Member]
Purchase Price Allocation
Intangible assets	$ 25,000
Finite-lived intangible assets acquired, Asset Life	7 years
Core and product technologies | Other 2015 Acquisition [Member]
Purchase Price Allocation
Intangible assets	$ 980
Finite-lived intangible assets acquired, Asset Life	5 years

Acquisitions (Identifiable Inta

Acquisitions (Identifiable Intangible Assets Acquired) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	May. 18, 2015	Jan. 08, 2015
Sanbolic, Inc. [Member]
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired			$ 45,300
Intangible assets acquired	$ 45,300
Sanbolic, Inc. [Member] | Core and product technologies
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	43,800
Sanbolic, Inc. [Member] | Customer relationships
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 1,500
Finite-lived intangible assets acquired, Asset Life	2 years
Sanbolic, Inc. [Member] | Telecommunication carrier relationships
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 0
Sanbolic, Inc. [Member] | Trade names
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	0
Grasshopper Group, LLC [Member]
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired		$ 71,400
Intangible assets acquired	71,400
Grasshopper Group, LLC [Member] | Core and product technologies
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 25,000
Finite-lived intangible assets acquired, Asset Life	7 years
Grasshopper Group, LLC [Member] | Customer relationships
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 37,900
Finite-lived intangible assets acquired, Asset Life	5 years
Grasshopper Group, LLC [Member] | Telecommunication carrier relationships
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 7,900
Finite-lived intangible assets acquired, Asset Life	2 years
Grasshopper Group, LLC [Member] | Trade names
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 600
Finite-lived intangible assets acquired, Asset Life	2 years
Other 2015 Acquisition [Member]
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 980
Finite-lived intangible assets acquired, Asset Life	5 years
Intangible assets acquired	$ 980
Other 2015 Acquisition [Member] | Core and product technologies
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 980
Finite-lived intangible assets acquired, Asset Life	5 years
Other 2015 Acquisition [Member] | Customer relationships
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 0
Other 2015 Acquisition [Member] | Telecommunication carrier relationships
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	0
Other 2015 Acquisition [Member] | Trade names
Business Acquisition [Line Items]
Finite-lived Intangible assets acquired	$ 0
Minimum | Sanbolic, Inc. [Member] | Core and product technologies
Business Acquisition [Line Items]
Finite-lived intangible assets acquired, Asset Life	5 years
Maximum | Sanbolic, Inc. [Member] | Core and product technologies
Business Acquisition [Line Items]
Finite-lived intangible assets acquired, Asset Life	6 years

Acquisitions Acquisitions (Pro

Acquisitions Acquisitions (Pro Forma) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Business Combinations [Abstract]
Revenues	$ 3,289,264	$ 3,170,128
Income from operations	349,577	276,344
Net income	$ 318,794	$ 234,957
Per share - basic (in USD per share)	$ 2.01	$ 1.38
Per share - diluted (in USD per share)	$ 1.99	$ 1.37

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]
Average remaining maturities for short-term available for sale investments, in months	6 months
Average remaining maturities for long-term available for sale investments, in years	3 years
Realized gains on the sales of available-for-sale investments	$ 800	$ 1,900
Realized losses on the sales of available-for-sale investments	1,000	500
Available-for-sale investments, carrying value	1,397,439	1,602,904
Available-for-sale investments, fair value	1,394,816	1,602,370
Gross unrealized losses	3,493	2,116
Cost method investments	19,900	16,600
Cost method investments, gain recorded on cost method investments	8,700	2,900
Cost method investment, impairment charge included other income	$ 3,300	$ 8,300	$ 3,700

Investments (Schedule Of Availa

Investments (Schedule Of Available-For-Sale Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Investment [Line Items]
Amortized Cost	$ 1,397,439	$ 1,602,904
Gross Unrealized Gains	870	1,582
Gross Unrealized Losses	(3,493)	(2,116)
Fair Value	1,394,816	1,602,370
Agency securities
Investment [Line Items]
Amortized Cost	530,981	637,474
Gross Unrealized Gains	757	1,296
Gross Unrealized Losses	(1,216)	(457)
Fair Value	530,522	638,313
Corporate securities
Investment [Line Items]
Amortized Cost	699,210	795,255
Gross Unrealized Gains	90	232
Gross Unrealized Losses	(1,929)	(1,372)
Fair Value	697,371	794,115
Municipal securities
Investment [Line Items]
Amortized Cost	14,872	48,744
Gross Unrealized Gains	14	17
Gross Unrealized Losses	(8)	(31)
Fair Value	14,878	48,730
Government securities
Investment [Line Items]
Amortized Cost	152,376	121,431
Gross Unrealized Gains	9	37
Gross Unrealized Losses	(340)	(256)
Fair Value	$ 152,045	$ 121,212

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Total assets	$ 364,930	$ 259,882
Liabilities, Fair Value Disclosure [Abstract]
Total liabilities	0	0
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total assets	1,397,905	1,597,770
Liabilities, Fair Value Disclosure [Abstract]
Total liabilities	3,678	9,692
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Total assets	1,562	6,073
Liabilities, Fair Value Disclosure [Abstract]
Total liabilities	0	0
Cash and cash equivalents | Corporate securities | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0
Cash and cash equivalents | Corporate securities | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	3,588
Cash and cash equivalents | Corporate securities | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0
Cash and cash equivalents | Recurring basis | Cash | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	261,962	230,370
Cash and cash equivalents | Recurring basis | Cash | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Cash and cash equivalents | Recurring basis | Cash | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Cash and cash equivalents | Recurring basis | Money market funds | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	102,968	29,512
Cash and cash equivalents | Recurring basis | Money market funds | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Cash and cash equivalents | Recurring basis | Money market funds | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Cash and cash equivalents | Recurring basis | Corporate securities | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		0
Cash and cash equivalents | Recurring basis | Corporate securities | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		267
Cash and cash equivalents | Recurring basis | Corporate securities | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		0
Available-for-sale securities | Recurring basis | Corporate securities | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale securities | Recurring basis | Corporate securities | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	695,809	788,042
Available-for-sale securities | Recurring basis | Corporate securities | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	1,562	6,073
Available-for-sale securities | Recurring basis | Agency securities | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale securities | Recurring basis | Agency securities | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	530,522	638,313
Available-for-sale securities | Recurring basis | Agency securities | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale securities | Recurring basis | Municipal securities | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale securities | Recurring basis | Municipal securities | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	14,878	48,730
Available-for-sale securities | Recurring basis | Municipal securities | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale securities | Recurring basis | Government securities | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Available-for-sale securities | Recurring basis | Government securities | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	152,045	121,212
Available-for-sale securities | Recurring basis | Government securities | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	0	0
Accrued expenses and other current liabilities | Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1)
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency derivatives	0	0
Accrued expenses and other current liabilities | Recurring basis | Significant Other Observable Inputs (Level 2)
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency derivatives	3,678	9,692
Accrued expenses and other current liabilities | Recurring basis | Significant Unobservable Inputs (Level 3)
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency derivatives	0	0
Estimate of Fair Value Measurement | Recurring basis
Assets, Fair Value Disclosure [Abstract]
Total assets	1,764,397	1,863,725
Liabilities, Fair Value Disclosure [Abstract]
Total liabilities	3,678	9,692
Estimate of Fair Value Measurement | Cash and cash equivalents | Corporate securities
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	3,588
Estimate of Fair Value Measurement | Cash and cash equivalents | Recurring basis | Cash
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	261,962	230,370
Estimate of Fair Value Measurement | Cash and cash equivalents | Recurring basis | Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	102,968	29,512
Estimate of Fair Value Measurement | Cash and cash equivalents | Recurring basis | Corporate securities
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents		267
Estimate of Fair Value Measurement | Available-for-sale securities | Recurring basis | Corporate securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	697,371	794,115
Estimate of Fair Value Measurement | Available-for-sale securities | Recurring basis | Agency securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	530,522	638,313
Estimate of Fair Value Measurement | Available-for-sale securities | Recurring basis | Municipal securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	14,878	48,730
Estimate of Fair Value Measurement | Available-for-sale securities | Recurring basis | Government securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	152,045	121,212
Estimate of Fair Value Measurement | Accrued expenses and other current liabilities | Recurring basis
Liabilities, Fair Value Disclosure [Abstract]
Foreign currency derivatives	3,678	9,692
Foreign currency | Prepaid expenses and other current assets | Recurring basis | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets, Fair Value Disclosure [Abstract]
Derivative assets fair value	0	0
Foreign currency | Prepaid expenses and other current assets | Recurring basis | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Derivative assets fair value	1,063	1,206
Foreign currency | Prepaid expenses and other current assets | Recurring basis | Significant Unobservable Inputs (Level 3)
Assets, Fair Value Disclosure [Abstract]
Derivative assets fair value	0	0
Foreign currency | Estimate of Fair Value Measurement | Prepaid expenses and other current assets | Recurring basis
Assets, Fair Value Disclosure [Abstract]
Derivative assets fair value	$ 1,063	$ 1,206

Fair Value Measurements (Asse56

Fair Value Measurements (Assets Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Cost method investments	$ 19,900	$ 16,600
Cost method investments, fair value of impaired investment	100	0
Cost method investment, impairment charge	3,300	8,300	$ 3,700
Impaired investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Cost method investments	3,400	8,300
Convertible debt securities | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at December 31, 2014	6,073
Purchases of Level 3 securities	1,775
Proceeds received on Level 3 securities	(501)
Total net realized losses included in earnings	(838)
Transfers out of Level 3	(4,947)
Balance at December 31, 2015	$ 1,562	$ 6,073

Fair Value Measurements (Additi

Fair Value Measurements (Additional Disclosures Regarding Fair Value Measurements) (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible Senior Notes	$ 1,324,992,000	$ 1,292,953,000
Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Closing trading price per $100 as of the last day of trading for the year	100
Convertible Senior Notes	1,567,364,000
Senior Notes Due 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible Senior Notes	$ 1,324,992,000

Accrued Expenses and Other Cu58

Accrued Expenses and Other Current Liabilities (Schedule of Accrued Expenses and Other Current Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued compensation and employee benefits	$ 184,286	$ 158,142
Other accrued expenses	133,182	139,937
Total	$ 317,468	$ 298,079

Employee Stock-Based Compensa59

Employee Stock-Based Compensation and Benefit Plans (Narrative) (Details) $ / shares in Units, $ in Thousands		1 Months Ended				12 Months Ended
		Jul. 31, 2015	Mar. 31, 2015$ / sharesshares	Mar. 31, 2014$ / sharesshares	Mar. 31, 2013$ / sharesshares	Dec. 31, 2015USD ($)installmentplan$ / sharesshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans offered | plan						1
Stock-based compensation | $	[1]					$ 147,368	$ 169,287	$ 183,941
Deferred Tax Asset Related to Stock-Based Compensation | $						46,100	46,900	57,100
Tax benefit from compensation expense | $						$ 52,700	$ 43,900	$ 55,700
The weighted average fair value per share of stock options granted (in dollars per share) | $ / shares								$ 56.97
Stock options granted in period (shares) | shares						0	0
401(k) Benefit Plan [Abstract]
Maximum annual contribution per employee (as a percent)						90.00%
Contribution per dollar of employee contribution						50.00%
Matching percent						3.00%
Defined Contribution Plan, Cost Recognized | $						$ 15,900	$ 14,400	$ 12,700
Employer contributions, vesting period						4 years
Employer contributions, annual vesting rate						25.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award expiration period						5 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award expiration period						10 years
Employee stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation | $						$ 2,500	20,900	48,900
Award expiration period						5 years
Stock option vesting period						3 years
Options assumed from acquisitions, award vesting period						3 years
The total intrinsic value of options exercised | $						$ 23,000	37,100	$ 77,700
Employee stock option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility rate, calculation basis, period								3 years 4 months 6 days
Employee stock option | First anniversary of date of grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage						33.30%
Employee stock option | Equal monthly installments after first anniversary of date of grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage						2.78%
Non-vested stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation | $						$ 1,400
Non-vested stock unit awards granted to senior level employees | shares						102,851
Total unrecognized compensation cost related to stock-based compensation | $						$ 7,100
Total unrecognized compensation cost recognition period (in years)						9 months 28 days
Non-vested stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period						1 year
Non-vested stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting period						3 years
Market and service condition stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested stock unit awards granted to senior level employees | shares			393,464	378,022	399,029
Period to determine actual stock grant following end of performance period						60 days
Performance period						3 years
Maximum percentage of market and service condition stock units that will ultimately vest						200.00%
Minimum overperformance percentage against benchmark index return for maximum stock issuance, percentage						40.00%
Maximum underperformance against benchmark index return before company discontinues issuance of stock, percentage (more than 20%)						20.00%
Percent of award issued if return is negative but benchmark index is met						75.00%
Non-vested stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation | $						$ 135,900	143,100	$ 130,200
Non-vested stock unit awards granted to senior level employees | shares						3,415,207
Number of shares represented by each award upon vesting | shares						1
Expected volatility rate, calculation basis, period						2 years 9 months 2 days
Granted (in dollars per share) | $ / shares			$ 61.01	$ 56.94	$ 89.93	$ 66.70
Maximum non-vested stock units issuable as percent of base number set forth in award agreement (percent)						100.00%
Share-based compensation award, stock vesting period, monthly installments | installment						12
Fair value of awards released | $						$ 132,900	118,300	95,400
Total unrecognized compensation cost related to stock-based compensation | $						$ 238,600
Total unrecognized compensation cost recognition period (in years)						1 year 9 months 17 days
Non-vested stock | Annual vesting on each anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage						33.33%
Non-vested stock | Third anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage						100.00%
2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance under 2005 Equity Incentive Plan | shares						29,000,000
Shares reserved for issuance under the 2005 Equity Incentive Plan | shares						26,917,012
Shares available for grant under the 2005 Equity Incentive Plan | shares						20,271,829
2005 ESPP Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Purchase Plan, total shares issued under plan | shares						3,872,661
Stock-based compensation | $						$ 7,600	$ 5,200	$ 4,900
2015 ESPP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance under 2005 Equity Incentive Plan | shares						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 | shares						12,000
Employee Stock Purchase Plan, purchase price offered as a percentage of fair market value on last day of payment period (percent)						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						245,029
Employee Stock Purchase Plan, purchase price offered as a percentage of fair market value on lower of first or last day of payment period (percent)		85.00%
Expected volatility rate, calculation basis, period						6 months
2015 ESPP Plan [Member] | Minimum
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
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%
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments

Employee Stock-Based Compensa60

Employee Stock-Based Compensation and Benefit Plans (Detail of the Total Stock-Based Compensation Recognized by Income Statement Classification) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	[1]	$ 147,368	$ 169,287	$ 183,941
Cost of services and maintenance revenues
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation		2,940	2,560	2,540
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation		47,723	55,560	63,448
Sales, marketing and services
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation		49,315	61,925	65,549
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation		$ 47,390	$ 49,242	$ 52,404
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments

Employee Stock-Based Compensa61

Employee Stock-Based Compensation and Benefit Plans (Assumptions Used To Value Option Grants) (Details)	1 Months Ended			12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2013
Employee stock option
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected dividend yield					0.00%
Employee stock option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor					0.39%
Approximate risk free interest rate					0.40%
Expected term (in years)					3 years 4 months 6 days
Non-vested stock
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Approximate risk free interest rate	0.85%	0.81%	0.33%
Expected term (in years)				2 years 9 months 2 days
Expected dividend yield	0.00%	0.00%	0.00%
Non-vested stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor	14.00%	19.00%	16.00%
Non-vested stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor	29.00%	38.00%	42.00%
ESPP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility factor				35.00%
Approximate risk free interest rate				0.25%
Expected term (in years)				6 months
Expected dividend yield				0.00%

Employee Stock-Based Compensa62

Employee Stock-Based Compensation and Benefit Plans (Schedule of Non-vested Stock Unit Activity) (Details) - Non-vested stock - $ / shares	1 Months Ended			12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2015
Number of Shares
Non-vested stock units at December 31, 2013 (in shares)				5,037,295
Granted (in shares)				3,415,207
Assumed from acquisitions (in shares)				142,822
Vested (in shares)				(1,971,312)
Forfeited (in shares)				(1,476,086)
Non-vested stock units at December 31, 2014 (in shares)				5,147,926
Weighted- Average Fair Value at Grant Date
Non-vested stock units at December 31, 2013 (in dollars per share)				$ 66.20
Granted (in dollars per share)	$ 61.01	$ 56.94	$ 89.93	66.70
Assumed (in dollars per share)				64.78
Vested (in dollars per share)				64.10
Forfeited (in dollars per share)				69.38
Non-vested stock units at December 31, 2014 (in dollars per share)				$ 65

Employee Stock-Based Compensa63

Employee Stock-Based Compensation and Benefit Plans (Schedule of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Number of Options
Outstanding at December 31, 2013 (in shares)	3,577,549
Exercised (in shares)	(1,875,339)
Forfeited or expired (in shares)	(390,098)
Outstanding at December 31, 2014 (in shares)	1,312,112	3,577,549
Weighted- Average Exercise Price
Outstanding at December 31, 2013 (in dollars per share)	$ 67.60
Exercised (in dollars per share)	59.87
Forfeited or expired (in dollars per share)	77.36
Outstanding at December 31, 2014 (in dollars per share)	$ 75.72	$ 67.60
Additional Disclosures on Options
Weighted- Average Remaining Contractual Life, Outstanding at December 31, 2013 (in years)	7 months	1 year 3 months 15 days
Aggregate Intrinsic Value, Outstanding at December 31, 2014	$ 5,978
Weighted- Average Remaining Contractual Life, Outstanding at December 31, 2014 (in years)	7 months	1 year 3 months 15 days
Exercisable at December 31, 2014 (in shares)	1,307,487
Weighted Average Exercise Price, Exercisable at December 31, 2014 (in dollars per share)	$ 75.82
Weighted-Average Remaining Contractual Life, Exercisable at December 31, 2014 (in years)	6 months 26 days
Aggregate intrinsic value, options exercisable at December 31, 2014	$ 5,857
Vested or expected to vest
Vested or expected to vest (in shares)	1,311,936
Weighted- Average Exercise Price (in dollars per share)	$ 75.73
Weighted- Average Remaining Contractual Life (in years)	6 months 28 days
Aggregate Intrinsic Value	$ 5,977

Capital Stock (Narrative) (Deta

Capital Stock (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 31, 2016	Sep. 30, 2015
Class of Stock [Line Items]
Stock repurchase program, authorized amount			$ 1,500,000,000	$ 6,300,000,000				$ 500,000,000
Available to repurchase common stock				32,700,000
Amount expended on share repurchases in open market transactions				755,704,000	$ 1,640,885,000	$ 406,326,000
Payments for Repurchase of Common Stock				$ 755,704,000	$ 1,640,885,000	$ 406,326,000
Total tax withholdings for share-based compensation (in shares)				679,694	560,239	444,657
Total tax withholdings for share-based compensation				$ 46,336,000	$ 33,672,000	$ 31,013,000
Preferred stock, shares authorized				5,000,000	5,000,000
Preferred stock, par value (in dollars per share)				$ 0.01	$ 0.01
Privately Negotiated Transaction [Member]
Class of Stock [Line Items]
Number of shares repurchased			1,700,000
Payments for Repurchase of Common Stock			$ 101,000,000
Purchase From Accelerated Share Repurchase [Member]
Class of Stock [Line Items]
Number of shares repurchased	2,600,000		21,800,000
Shares repurchased under the ASR		$ 1,400,000,000	$ 1,400,000,000
Open Market Purchases [Member]
Class of Stock [Line Items]
Amount expended on share repurchases in open market transactions				$ 755,700,000	$ 139,900,000	$ 406,300,000
Number of shares repurchased				10,716,850	2,046,400	6,563,986
Average per share price on share repurchases in open market transactions (in dollars per share)				$ 70.52	$ 68.36	$ 61.90
Subsequent Event [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount							$ 400,000,000

Commitments and Contingencies65

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loss Contingencies [Line Items]
Rental expense		$ 97,100	$ 77,100	$ 70,900
Restructuring	[1]	100,411	20,424	0
Sublease income		400	$ 300	$ 300
Liability for loss on lease obligation		20,700
Purchase obligations anticipated for 2015		11,400
Contingent obligations to purchase inventory		18,700
Santa Clara Office
Loss Contingencies [Line Items]
Liability for loss on lease obligation		15,000
2015 Restructuring Program [Member]
Loss Contingencies [Line Items]
Restructuring		68,900
Facility Closing [Member]
Loss Contingencies [Line Items]
Restructuring		22,100
Facility Closing [Member] | 2015 Restructuring Program [Member]
Loss Contingencies [Line Items]
Restructuring		$ 22,100
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments

Commitments and Contingencies66

Commitments and Contingencies (Schedule of Lease Commitments) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Operating Leases
2,016	$ 64,539
2,017	52,243
2,018	46,199
2,019	43,119
2,020	35,363
Thereafter	153,139
Total	394,602
Sublease Income
2,016	272
2,017	218
2,018	204
2,019	0
2,020	0
Thereafter	0
Total	$ 694

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ (16,673)		$ (15,167)	$ (16,673)	$ (15,167)
Decrease in unrecognized tax benefits for closed tax years		$ 20,300		14,064	11,465
Unrecognized tax benefits offsetting against short-term tax assets	25,400			25,400
Income tax (benefit) expense				(7,484)	$ 23,983	$ 48,367
Research
Operating Loss Carryforwards [Line Items]
Undistributed earnings from foreign subsidiaries	2,330,000			2,330,000
Tax credit carryforward	65,600			65,600
Income tax (benefit) expense	19,200		$ 12,300
United States
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	113,100			113,100
Foreign jurisdictions
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	$ 32,300			$ 32,300

Income Taxes (United States and

Income Taxes (United States and Foreign Components of Income Before Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Expense (Benefit), Continuing Operations, by Jurisdiction [Abstract]
United States	$ (3,332)	$ 82,032	$ 142,085
Foreign	315,209	193,674	245,805
Income before income taxes	$ 311,877	$ 275,706	$ 387,890

Income Taxes (Components of the

Income Taxes (Components of the Provision for Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Federal	$ 27,860	$ 22,377	$ 51,389
Foreign	43,796	30,878	37,221
State	10,238	7,710	11,605
Total current	81,894	60,965	100,215
Deferred:
Federal	(75,479)	(26,922)	(34,897)
Foreign	(2,746)	(1,023)	(8,413)
State	(11,153)	(9,037)	(8,538)
Total deferred	(89,378)	(36,982)	(51,848)
Total provision	$ (7,484)	$ 23,983	$ 48,367

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Liabilities by Balance Sheet Classification (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Assets and Liabilities by Balance Sheet Classification [Abstract]
Deferred tax assets - current	[1]	$ 0	$ 45,892
Deferred tax liabilities - current	[1]	0	(1,053)
Deferred tax assets- non current		215,196	128,198
Deferred tax liabilities - non current		(3,903)	(8,722)
Total net deferred tax assets		$ 211,293	$ 164,315
[1]	During the year ended December 31, 2015, the Company elected to early adopt an accounting standard update on income taxes on a prospective basis. The new authoritative guidance requires deferred tax liabilities and assets along with any related valuation allowance to be classified as noncurrent on the consolidated balance sheet. The December 31, 2014 consolidated balance sheet was not retrospectively adjusted.

Income Taxes (Components of Def

Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Accruals and reserves	$ 36,628	$ 27,105
Deferred revenue	84,631	65,541
Tax credits	41,444	43,211
Net operating losses	50,466	75,318
Other	7,527	12,878
Stock based compensation	46,582	63,993
Valuation allowance	(16,673)	(15,167)
Total deferred tax assets	250,605	272,879
Deferred tax liabilities:
Depreciation and amortization	(16,113)	(16,835)
Acquired technology	(15,825)	(82,357)
Prepaid expenses	(7,374)	(9,372)
Total deferred tax liabilities	(39,312)	(108,564)
Total net deferred tax assets	$ 211,293	$ 164,315

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of the Company's Effective Tax Rate to the Statutory Federal Rate) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Federal statutory taxes	35.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	0.90%	1.20%	1.20%
Foreign operations	(22.30%)	(13.80%)	(14.80%)
Permanent differences	6.10%	3.30%	(1.10%)
Change in deferred tax liability related to acquired intangibles	(6.60%)	(5.90%)	0.00%
Tax credits	(13.40%)	(13.70%)	(10.90%)
Stock option compensation	0.50%	1.90%	0.40%
Change in accruals for uncertain tax positions	(3.20%)	(0.30%)	3.30%
Other	0.60%	1.00%	(0.60%)
Effective income tax rate	(2.40%)	8.70%	12.50%

Income Taxes (Reconciliation 73

Income Taxes (Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits [Roll Forward]
Beginning balance		$ 66,918	$ 63,792
Additions based on tax positions related to the current year		6,613	5,711
Additions for tax positions of prior years		4,675	12,998
Reductions related to the expiration of statutes of limitations		(9,521)	(4,118)
Settlements	$ (20,300)	(14,064)	(11,465)
Ending balance		$ 54,621	$ 66,918

Segment Information (Narrative)

Segment Information (Narrative) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015USD ($)customer	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)customer	Sep. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2015USD ($)customersegment	Dec. 31, 2014USD ($)customer	Dec. 31, 2013USD ($)customer
Concentration Risk [Line Items]
Net revenues | $	$ 904,763	$ 813,270	$ 796,759	$ 760,802	$ 851,483	$ 758,994	$ 781,560	$ 750,819	$ 3,275,594	$ 3,142,856	$ 2,918,434
Number of reportable segments | segment									2
Percentage of international revenues accounting for the Company's net revenues									43.10%	45.20%	45.40%
US to International Revenues
Concentration Risk [Line Items]
Net revenues | $									$ 180,200	$ 193,800	$ 215,300
Net revenues | Customer concentration risk
Concentration Risk [Line Items]
Number of customers meeting concentration risk threshold | customer	0								0
Ingram Micro | Net revenues | Customer concentration risk
Concentration Risk [Line Items]
Number of customers meeting concentration risk threshold | customer					1					1	1
Concentration risk percentage										13.00%	14.00%

Segment Information (Net Revenu

Segment Information (Net Revenues And Profit By Segment) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net revenues		$ 904,763	$ 813,270	$ 796,759	$ 760,802	$ 851,483	$ 758,994	$ 781,560	$ 750,819	$ 3,275,594	$ 3,142,856	$ 2,918,434
Segment profit		$ 112,406	$ 63,798	$ 122,149	$ 51,732	$ 117,408	$ 58,597	$ 54,419	$ 71,887	350,085	302,311	380,717
Amortization and impairment of intangible assets	[1]									(239,915)	(192,325)	(139,541)
Patent litigation charge	[1]									0	(20,727)	0
Restructuring	[1]									(100,411)	(20,424)	0
Net interest and other (expense) income, net	[1]									(38,208)	(26,605)	7,173
Stock-based compensation	[1]									(147,368)	(169,287)	(183,941)
Separation Related Costs	[1]									(6,352)	0	0
Consolidated income before income taxes										311,877	275,706	387,890
Enterprise and Service Provider
Segment Reporting Information [Line Items]
Net revenues										2,544,302	2,491,294	2,335,562
Segment profit	[2]									759,614	589,076	588,138
Mobility Apps division
Segment Reporting Information [Line Items]
Net revenues										731,292	651,562	582,872
Segment profit	[2]									83,535	115,998	116,061
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Other	[1]									$ 982	$ 0	$ 0
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments
[2]	Effective January 1, 2015, the Company revised its methodology for allocating certain corporate costs within General and administrative expenses to more closely align these costs to the employees directly utilizing the related services within each of its reporting segments in connection with organizational structure changes that changed the manner in which shared support services are provided. This change in presentation does not affect the Company's consolidated financial position, results from operations or cash flows.

Segment Information (Identifiab

Segment Information (Identifiable Assets By Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Identifiable assets	$ 5,481,438	$ 5,512,007
Long-lived assets	373,817	367,779
United States
Segment Reporting Information [Line Items]
Long-lived assets	294,982	284,463
United Kingdom
Segment Reporting Information [Line Items]
Long-lived assets	28,851	29,556
Other countries
Segment Reporting Information [Line Items]
Long-lived assets	49,984	53,760
Enterprise and Service Provider
Segment Reporting Information [Line Items]
Identifiable assets	4,578,436	4,879,513
Mobility Apps division
Segment Reporting Information [Line Items]
Identifiable assets	$ 903,002	$ 632,494

Segment Information (Revenues B

Segment Information (Revenues By Product Grouping) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net revenues		$ 904,763	$ 813,270	$ 796,759	$ 760,802	$ 851,483	$ 758,994	$ 781,560	$ 750,819	$ 3,275,594	$ 3,142,856	$ 2,918,434
Enterprise and Service Provider
Segment Reporting Information [Line Items]
Net revenues										2,544,302	2,491,294	2,335,562
Enterprise and Service Provider | Workspace Services revenues
Segment Reporting Information [Line Items]
Net revenues	[1]									1,645,331	1,606,903	1,549,383
Enterprise and Service Provider | Delivery Networking revenues
Segment Reporting Information [Line Items]
Net revenues	[2]									741,121	695,734	634,598
Enterprise and Service Provider | Professional services
Segment Reporting Information [Line Items]
Net revenues	[3]									147,488	175,541	138,879
Enterprise and Service Provider | Other
Segment Reporting Information [Line Items]
Net revenues										10,362	13,116	12,702
Mobility Apps division
Segment Reporting Information [Line Items]
Net revenues										$ 731,292	$ 651,562	$ 582,872
[1]	Workspace Services revenues are primarily comprised of sales from the Company’s windows app delivery products, which includes XenDesktop and XenApp, and the Company's mobile app delivery products, which include XenMobile and related license updates and maintenance and support.
[2]	Delivery Networking revenues primarily include NetScaler, ByteMobile Smart Capacity and CloudBridge products and related license updates and maintenance and support.
[3]	Professional services revenues are primarily comprised of revenues from consulting services and product training and certification services.

Segment Information (Revenues78

Segment Information (Revenues By Geographic Location) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 904,763	$ 813,270	$ 796,759	$ 760,802	$ 851,483	$ 758,994	$ 781,560	$ 750,819	$ 3,275,594	$ 3,142,856	$ 2,918,434
Enterprise and Service Provider
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									2,544,302	2,491,294	2,335,562
Enterprise and Service Provider | Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									1,394,985	1,328,851	1,263,673
Enterprise and Service Provider | EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									866,775	859,404	785,862
Enterprise and Service Provider | Asia-Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									282,542	303,039	286,027
Mobility Apps division
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									731,292	651,562	582,872
Mobility Apps division | Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									616,900	541,145	488,307
Mobility Apps division | EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									91,324	87,705	73,529
Mobility Apps division | Asia-Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									$ 23,068	$ 22,712	$ 21,036

Convertible Senior Notes (Detai

Convertible Senior Notes (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Net carrying amount		$ 1,324,992	$ 1,292,953
Senior Notes Due 2019
Debt Instrument [Line Items]
Principal		1,437,500
Less: note discount		(112,508)
Net carrying amount		1,324,992
Equity component	[1]	$ 162,869
[1]	Recorded in the consolidated balance sheet within additional paid-in capital.

Convertible Senior Notes - Sche

Convertible Senior Notes - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Amortization of debt discount	$ 36,013	$ 23,293	$ 0
Senior Notes Due 2019
Debt Instrument [Line Items]
Contractual interest expense	7,188	4,792
Amortization of debt issuance costs	3,974	2,461
Amortization of debt discount	32,039	20,832
Interest Expense, Debt	$ 43,201	$ 28,085

Convertible Senior Notes - Addi

Convertible Senior Notes - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions		Apr. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2015
Debt Instrument [Line Items]
Proceeds from convertible debt offering					$ 0	$ 1,415,717,000	$ 0
Stock repurchase program, authorized amount				$ 1,500,000,000	6,300,000,000			$ 500,000,000
Payments for Repurchase of Common Stock					755,704,000	1,640,885,000	$ 406,326,000
Convertible Senior Notes					$ 1,324,992,000	$ 1,292,953,000
Senior Notes Due 2019
Debt Instrument [Line Items]
Shares Of Common Stock Covered By Note Hedges		16
Debt Instrument, Convertible, Conversion Ratio		0.011111
Convertible Debt		$ 1,440,000,000
Debt Instrument, Interest Rate, Stated Percentage		0.50%
Proceeds from convertible debt offering		$ 1,420,000,000
Payments for (Proceeds from) Hedge, Investing Activities		82,600,000
Convertible debt, conversion price (in dollars per share)					$ 90
Debt Instrument, Face Amount		$ 1,000
Repurchase Price as a Percent of Principal Amount		100.00%
Amortization, Effective Interest Method, Percent					3.00%
Convertible Senior Notes					$ 1,324,992,000
Equity component	[1]				162,869,000
Deferred Tax Liabilities, Deferred Expense, Deferred Financing Costs					$ 8,200,000
Additional Warrant Transaction		16
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 120
Privately Negotiated Transaction [Member]
Debt Instrument [Line Items]
Payments for Repurchase of Common Stock				101,000,000
Purchase From Accelerated Share Repurchase [Member]
Debt Instrument [Line Items]
Shares repurchased under the ASR			$ 1,400,000,000	$ 1,400,000,000
[1]	Recorded in the consolidated balance sheet within additional paid-in capital.

Credit Facility (Details)

Credit Facility (Details)	Jan. 07, 2015USD ($)	Dec. 31, 2015USD ($)
Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility term	5 years
Unsecured credit facility maximum amount	$ 250,000,000
Potential increase in revolving credit facility commitment	$ 250,000,000
Consolidated leverage ratio (note more than)	3.5
Consolidated interest coverage ratio (not less than)	3
Line of Credit [Member]
Line of Credit Facility [Line Items]
Weighted average interest rate (percent)		1.82%
Amount outstanding		$ 0
Line of Credit [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Unsecured credit facility maximum amount	$ 25,000,000
Line of Credit [Member] | Swing Line Loans [Member]
Line of Credit Facility [Line Items]
Unsecured credit facility maximum amount	$ 10,000,000
London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Basis spread on LIBOR (percent)		1.10%
Minimum | Line of Credit [Member]
Line of Credit Facility [Line Items]
Quarterly facility fee (percent)		0.125%
Minimum | London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Basis spread on LIBOR (percent)		1.00%
Maximum | Line of Credit [Member]
Line of Credit Facility [Line Items]
Quarterly facility fee (percent)		0.20%
Maximum | London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Basis spread on LIBOR (percent)		1.30%

Derivative Financial Instrume83

Derivative Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash flow hedge instrument term, maximum historical term	12 months
Cash flow hedge instrument term, maximum	18 months
Cumulative unrealized gain (loss) on cash flow derivative instruments in accumulated other comprehensive loss	$ 2.3	$ 8.3

Derivative Financial Instrume84

Derivative Financial Instruments (Schedule Of The Fair Values Of Derivative Instruments) (Details) - Cash flow hedging - Foreign currency - Forward contracts - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivatives Designated as Hedging Instruments | Prepaid expenses and other current assets
Asset Derivatives
Derivative assets fair value	$ 436	$ 435
Derivatives Designated as Hedging Instruments | Accrued expenses and other current liabilities
Liability Derivatives
Derivative liabilities fair value	2,895	9,364
Derivatives Not Designated as Hedging Instruments | Prepaid expenses and other current assets
Asset Derivatives
Derivative assets fair value	627	771
Derivatives Not Designated as Hedging Instruments | Accrued expenses and other current liabilities
Liability Derivatives
Derivative liabilities fair value	$ 783	$ 328

Derivative Financial Instrume85

Derivative Financial Instruments (Schedule Of Effect Of Derivative Instruments On Financial Performance) (Details) - Cash flow hedging - Foreign currency - Forward contracts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivatives Designated as Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive (Loss) Income (Effective Portion)	$ 6,090	$ (11,197)
Derivatives Designated as Hedging Instruments | Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) Gain Reclassified from Accumulated Other Comprehensive Loss (Effective Portion)	(13,027)	2,123
Derivatives Not Designated as Hedging Instruments | Other expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain Recognized in Income on Derivative	$ 1,669	$ 3,551

Derivative Financial Instrume86

Derivative Financial Instruments (Schedule Of Net Notional Foreign Currency Forward Contracts Outstanding) (Details) - Dec. 31, 2015 € in Thousands, ₨ in Thousands, ¥ in Thousands, ¥ in Thousands, £ in Thousands, SGD in Thousands, SFr in Thousands, HKD in Thousands, DKK in Thousands, CAD in Thousands, BRL in Thousands, AUD in Thousands

AUD

INR (₨)

DKK

GBP (£)

JPY (¥)

CNY (¥)

CHF (SFr)

HKD

BRL

SGD

EUR (€)

CAD

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Net notional foreign currency forward contracts outstanding

AUD 1,433

₨ 660,475

DKK 19,000

£ 21,510

¥ 449,015

¥ 35,000

SFr 20,400

HKD 50,813

BRL 5,700

SGD 11,629

€ 1,500

CAD 4,700

Earnings Per Share (Net Income

Earnings Per Share (Net Income Per Share Basic And Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerator:
Net income	$ 131,274	$ 55,925	$ 103,275	$ 28,887	$ 95,228	$ 47,532	$ 53,024	$ 55,939	$ 319,361	$ 251,723	$ 339,523
Denominator:
Denominator for basic earnings per share - weighted-average shares outstanding									158,874	169,879	186,672
Effect of dilutive employee stock awards:
Employee stock awards									1,488	1,391	1,573
Denominator for diluted earnings per share - weighted-average shares outstanding									160,362	171,270	188,245
Net income per share attributable to Citrix Systems, Inc. stockholders - basic (in dollars per share)	$ 0.85	$ 0.35	$ 0.64	$ 0.18	$ 0.59	$ 0.29	$ 0.31	$ 0.30	$ 2.01	$ 1.48	$ 1.82
Net income per share attributable to Citrix Systems, Inc. stockholders - diluted (in dollars per share)	0.84	$ 0.35	$ 0.64	$ 0.18	$ 0.58	$ 0.29	$ 0.31	$ 0.30	$ 1.99	$ 1.47	$ 1.80
Anti-dilutive weighted-average shares									2,151	3,026	3,647
Senior Notes Due 2019
Effect of dilutive employee stock awards:
Convertible debt, conversion price (in dollars per share)	$ 90								$ 90

Comprehensive Income (Changes i

Comprehensive Income (Changes in Accumulated Other Comprehensive Loss by Component) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2014	$ (36,790)
Other comprehensive income (loss) before reclassifications	(4,934)
Amounts reclassified from Accumulated other comprehensive loss	13,197
Other comprehensive income (loss)	8,263	$ (41,741)	$ 12,656
Balance at December 31, 2015	(28,527)	(36,790)
Foreign currency
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2014	(16,346)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from Accumulated other comprehensive loss	0
Other comprehensive income (loss)	0
Balance at December 31, 2015	(16,346)	(16,346)
Unrealized gain (loss) on available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2014	(990)
Other comprehensive income (loss) before reclassifications	(2,080)
Amounts reclassified from Accumulated other comprehensive loss	170
Other comprehensive income (loss)	(1,910)
Balance at December 31, 2015	(2,900)	(990)
Unrealized gain (loss) on derivative instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2014	(8,345)
Other comprehensive income (loss) before reclassifications	(6,937)
Amounts reclassified from Accumulated other comprehensive loss	13,027
Other comprehensive income (loss)	6,090
Balance at December 31, 2015	(2,255)	(8,345)
Other comprehensive loss on pension liability
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at December 31, 2014	(11,109)
Other comprehensive income (loss) before reclassifications	4,083
Amounts reclassified from Accumulated other comprehensive loss	0
Other comprehensive income (loss)	4,083
Balance at December 31, 2015	$ (7,026)	$ (11,109)

Comprehensive Income (Reclassif

Comprehensive Income (Reclassifications out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense, net										$ 5,730	$ 7,694	$ 893
Operating expenses										(2,311,145)	(2,220,326)	(2,034,922)
Net income		$ (131,274)	$ (55,925)	$ (103,275)	$ (28,887)	$ (95,228)	$ (47,532)	$ (53,024)	$ (55,939)	(319,361)	$ (251,723)	$ (339,523)
Amount reclassified from Accumulated other comprehensive loss, net of tax
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income										13,197
Amount reclassified from Accumulated other comprehensive loss, net of tax | Unrealized net loss on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense, net										170
Amount reclassified from Accumulated other comprehensive loss, net of tax | Unrealized net loss on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating expenses	[1]									$ 13,027
[1]	Operating expenses amounts allocated to Research and development, Sales, marketing and services, and General and administrative are not individually significant.

Restructuring - (Restructuring

Restructuring - (Restructuring Plans) (Details) $ in Thousands		Feb. 18, 2016position	Dec. 31, 2015USD ($)position	Jun. 30, 2015position	Dec. 31, 2015USD ($)position	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring	[1]				$ 100,411	$ 20,424	$ 0
2015 Other Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Number of full-time positions eliminated | position			350
Restructuring					29,732
2015 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Number of full-time positions eliminated | position				700
Restructuring					$ 68,900
2014 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Number of full-time positions eliminated | position					325
Restructuring costs since inception of the program			$ 22,200		$ 22,200
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring					76,629
Employee Severance [Member] | 2015 Other Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring					29,732
Employee Severance [Member] | 2015 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring					44,837
Employee Severance [Member] | 2014 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring					2,060
Minimum | Employee Severance [Member] | 2015 Other Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Total expected restructuring cost			55,000		55,000
Maximum | Employee Severance [Member] | 2015 Other Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Total expected restructuring cost			$ 60,000		$ 60,000
Scenario, Forecast | 2015 Other Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Number of full-time positions eliminated | position		700
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments

Restructuring - (Restructurin91

Restructuring - (Restructuring Charges by Segment) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring	[1]	$ 100,411	$ 20,424	$ 0
Enterprise and Service Provider | 2014 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		1,724	14,092
Enterprise and Service Provider | 2015 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		67,548	0
Enterprise and Service Provider | 2015 Other Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		27,680	0
Mobility Apps division | 2014 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		50	6,332
Mobility Apps division | 2015 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		1,357	0
Mobility Apps division | 2015 Other Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		$ 2,052	$ 0
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments

Restructuring - (Activity in Re

Restructuring - (Activity in Restructuring Accruals) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]
Balance, beginning		$ 2,780
Employee severance and consolidation of leased facility costs	[1]	100,411	$ 20,424	$ 0
Payments		(60,827)
Reversal of previous charges		(286)
Balance, ending		40,396	2,780
2014 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning		2,780
Payments		(3,433)
Reversal of previous charges		(286)
Balance, ending		1,121	2,780
2015 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning		0
Employee severance and consolidation of leased facility costs		68,900
Payments		(44,243)
Reversal of previous charges		0
Balance, ending		22,694	0
2015 Other Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning		0
Employee severance and consolidation of leased facility costs		29,732
Payments		(13,151)
Reversal of previous charges		0
Balance, ending		16,581	$ 0
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Employee severance and consolidation of leased facility costs		76,629
Balance, ending		40,400
Employee Severance [Member] | 2014 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Employee severance and consolidation of leased facility costs		2,060
Employee Severance [Member] | 2015 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Employee severance and consolidation of leased facility costs		44,837
Employee Severance [Member] | 2015 Other Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Employee severance and consolidation of leased facility costs		29,732
Facility Closing [Member]
Restructuring Reserve [Roll Forward]
Employee severance and consolidation of leased facility costs		22,100
Facility Closing [Member] | 2014 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Employee severance and consolidation of leased facility costs		0
Facility Closing [Member] | 2015 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Employee severance and consolidation of leased facility costs		22,100
Facility Closing [Member] | 2015 Other Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Employee severance and consolidation of leased facility costs		$ 0
[1]	Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments

Quarterly Financial Informati93

Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Data [Abstract]
Net revenues	$ 904,763	$ 813,270	$ 796,759	$ 760,802	$ 851,483	$ 758,994	$ 781,560	$ 750,819	$ 3,275,594	$ 3,142,856	$ 2,918,434
Gross margin	702,010	667,016	664,008	628,196	676,831	623,009	606,304	616,493	2,661,230	2,522,637	2,415,639
Income from operations	112,406	63,798	122,149	51,732	117,408	58,597	54,419	71,887	350,085	302,311	380,717
Net income	$ 131,274	$ 55,925	$ 103,275	$ 28,887	$ 95,228	$ 47,532	$ 53,024	$ 55,939	$ 319,361	$ 251,723	$ 339,523
Basic (USD per share)	$ 0.85	$ 0.35	$ 0.64	$ 0.18	$ 0.59	$ 0.29	$ 0.31	$ 0.30	$ 2.01	$ 1.48	$ 1.82
Diluted (USD per share)	$ 0.84	$ 0.35	$ 0.64	$ 0.18	$ 0.58	$ 0.29	$ 0.31	$ 0.30	$ 1.99	$ 1.47	$ 1.80

Valuation and Qualifying Acco94

Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		$ 2,200
Balance at End of Period		1,400	$ 2,200
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		3,791	3,292		$ 3,883
Charged to Expense		5,664	2,861		1,046
Charged to Other Accounts	[1]	0	76		0
Deductions	[2]	3,174	2,438		1,637
Balance at End of Period		6,281	3,791		3,292
Allowance for returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		2,185	2,062		2,564
Charged to Expense		0	0		0
Charged to Other Accounts	[3]	3,276	5,049		4,473
Deductions	[4]	4,023	4,926		4,975
Balance at End of Period		1,438	2,185		2,062
Valuation allowance for deferred tax assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		15,167	26,465		18,185
Charged to Expense		0	0		0
Charged to Other Accounts		1,506	(11,298)	[5]	8,280	[5]
Deductions		0	0		0
Balance at End of Period		$ 16,673	$ 15,167		$ 26,465
[1]	Adjustments from acquisitions.
[2]	Uncollectible accounts written off, net of recoveries.
[3]	Charged against revenues.
[4]	Credits issued for returns.
[5]	Related to deferred tax assets on foreign tax credits, net operating loss carryforwards, and depreciation.