Mandiant (MNDT) 10-Q 6 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	May. 02, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	FIREEYE, INC.
Entity Central Index Key	1,370,880
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		166,355,306

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 175,113	$ 402,102
Short-term investments	746,027	767,775
Accounts receivable, net of allowance for doubtful accounts of $1,816 and $2,021 at March 31, 2016 and December 31, 2015, respectively	141,247	172,752
Inventories	10,778	13,747
Prepaid expenses and other current assets	35,078	30,883
Total current assets	1,108,243	1,387,259
Property and equipment, net	81,324	78,368
Goodwill	974,184	750,288
Intangible assets, net	290,595	214,560
Deposits and other long-term assets	12,084	10,998
TOTAL ASSETS	2,466,430	2,441,473
CURRENT LIABILITIES:
Accounts payable	37,716	43,650
Accrued and other current liabilities	36,082	29,820
Accrued compensation	105,893	79,294
Deferred revenue, current portion	329,095	305,169
Total current liabilities	508,786	457,933
Convertible senior notes, net	714,978	706,198
Deferred revenue, non-current portion	236,987	221,829
Other long-term liabilities	9,298	11,141
Total liabilities	$ 1,470,049	$ 1,397,101
Commitments and contingencies
Stockholders' equity:
Common stock, par value of $0.0001 per share; 1,000,000 shares authorized, 166,223 shares and 161,643 shares issued and outstanding as of March 31, 2016 and December 31, 2015, respectively	$ 17	$ 16
Additional paid-in capital	2,512,269	2,403,088
Treasury stock, at cost; 3,333 shares as of March 31, 2016 and December 31, 2015	(150,000)	(150,000)
Accumulated other comprehensive loss	(62)	(2,225)
Accumulated deficit	(1,365,843)	(1,206,507)
Total stockholders’ equity	996,381	1,044,372
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 2,466,430	$ 2,441,473

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,816	$ 2,021
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (shares)	166,223,000	161,643,000
Common stock, shares outstanding (shares)	166,223,000	161,643,000
Treasury stock (shares)	3,333,000	3,333,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenue:
Product	$ 33,707	$ 40,237
Subscription and services	134,259	85,133
Total revenue	167,966	125,370
Cost of revenue:
Product	17,133	15,200
Subscription and services	54,297	36,851
Total cost of revenue	71,430	52,051
Total gross profit	96,536	73,319
Operating expenses:
Research and development	85,983	65,605
Sales and marketing	123,028	107,595
General and administrative	42,256	32,607
Restructuring charges	1,670	0
Total operating expenses	252,937	205,807
Operating loss	(156,401)	(132,488)
Interest income	1,465	269
Interest expense	(11,809)	0
Other income (expense), net	815	(768)
Loss before income taxes	(165,930)	(132,987)
Provision for (benefit from) income taxes	(10,030)	977
Net loss attributable to common stockholders	$ (155,900)	$ (133,964)
Net loss per share attributable to common stockholders, basic and diluted (usd per share)	$ (0.98)	$ (0.88)
Weighted average shares used in computing net loss per share attributable to common stockholders, basic and diluted (shares)	158,781	151,651

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (155,900)	$ (133,964)
Change in net unrealized gains/(losses) on available-for-sale investments, net of tax	2,163	403
Comprehensive loss	$ (153,737)	$ (133,561)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (155,900)	$ (133,964)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	30,503	26,581
Stock-based compensation	64,239	49,875
Non-cash interest expense related to convertible senior notes	8,780	0
Deferred income taxes	(11,053)	82
Other	938	509
Changes in operating assets and liabilities, net of business acquisitions:
Accounts receivable	43,144	32,736
Inventories	2,325	(2,554)
Prepaid expenses and other assets	(2,152)	127
Accounts payable	(3,391)	(4,219)
Accrued liabilities	902	2,068
Accrued transaction costs of acquiree	(7,727)	0
Accrued compensation	(8,989)	(2,675)
Deferred revenue	17,997	26,221
Other long-term liabilities	(2,132)	1,997
Net cash used in operating activities	(22,516)	(3,216)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment and demonstration units	(14,257)	(12,669)
Purchases of short-term investments	(88,805)	(39,857)
Proceeds from maturities of short-term investments	111,319	34,655
Business acquisitions, net of cash acquired	(204,926)	0
Lease deposits	(678)	(370)
Net cash used in investing activities	(197,347)	(18,241)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of debt of acquired business	(8,842)	0
Payment of shares withheld for taxes	(1,124)	0
Proceeds from exercise of equity awards	2,840	11,870
Net cash (used in) provided by financing activities	(7,126)	11,870
Net change in cash and cash equivalents	(226,989)	(9,587)
Cash and cash equivalents, beginning of period	402,102	146,363
Cash and cash equivalents, end of period	175,113	136,776
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for income taxes	1,888	536
Cash paid for interest	22	0
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Vesting of early exercised stock options	496	604
Common stock issued in connection with acquisitions	39,300	0
Contingent earn-out in connection with acquisitions	35,588	0
Purchases of property and equipment and demonstration units in accounts payable and accrued liabilities	$ 5,779	$ 5,382

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Summary of Significant Accounting Policies	Description of Business and Summary of Significant Accounting Policies Description of Business FireEye, Inc., with principal executive offices located in Milpitas, California, was incorporated as NetForts, Inc. on February 18, 2004, under the laws of the State of Delaware, and changed its name to FireEye, Inc. on September 7, 2005. FireEye, Inc. and its wholly owned subsidiaries (collectively, the “Company”, “we”, “us” or “our”) is a leader in stopping advanced cyber attacks that use advanced malware, zero-day exploits, and APT (“Advanced Persistent Threat”) tactics. Our solutions supplement traditional and next-generation firewalls, Intrusion Prevention Systems (“IPS”), anti-virus, and gateways, which cannot stop advanced threats, leaving security holes in networks. We offer a solution that detects and blocks attacks across Web, email, endpoint, file and mobile threat vectors, as well as latent malware resident on file shares. Our solutions address all stages of an attack lifecycle with a signature-less engine utilizing stateful attack analysis to detect zero-day threats. In February 2016, we acquired Invotas International Corporation (“Invotas”), a provider of security automation and orchestration technology. We paid upfront cash consideration of $17.7 million and issued 742,026 shares of our common stock with an estimated fair value of $11.1 million . In January 2016, we acquired iSIGHT Security, Inc. (d/b/a iSIGHT Partners, Inc.) (“iSIGHT”), one of the world’s leading providers of cyber threat intelligence for global enterprises. We paid upfront cash consideration of $192.8 million , incurred liabilities of $35.6 million contingent upon the achievement of a threat intelligence bookings target on or before the end of the second quarter of 2018, and issued 1,793,305 shares of our common stock with an estimated fair value of $28.2 million . In June 2015, we issued $460.0 million principal amount of 1.000% Convertible Senior Notes due 2035 (the “Series A Notes”) and $460.0 million principal amount of 1.625% Convertible Senior Notes due 2035 (the “Series B Notes” and together with the Series A Notes, the “Convertible Senior Notes”), in a private placement to qualified institutional purchasers pursuant to an exemption from registration provided by Section 4(a)(2) and Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). We recognized total net proceeds after the initial purchasers' discount and issuance costs of $896.5 million . In connection with the issuance of the Convertible Senior Notes, we also entered into privately negotiated prepaid forward stock purchase transactions (each a “Prepaid Forward”) with one of the initial purchasers of the Convertible Senior Notes, pursuant to which we paid approximately $150.0 million . The amount prepaid is equivalent to approximately 3.3 million shares which are to be settled on or around June 1, 2020 and June 1, 2022, respectively, subject to any early settlement in whole or part of each Prepaid Forward. We sell the majority of our products, subscriptions and services to end-customers through distributors, resellers, and strategic partners, with a lesser percentage of sales directly to end-customers. Basis of Presentation and Consolidation The accompanying unaudited condensed consolidated financial statements include the accounts of FireEye, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”), and following the requirements of the Securities and Exchange Commission (“SEC”), for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. These unaudited condensed consolidated financial statements have been prepared on the same basis as our annual consolidated financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, that are necessary for a fair statement of our financial information. The results of operations for the three months ended March 31, 2016 are not necessarily indicative of the results to be expected for the year ending December 31, 2016 or for any other interim period or for any other future year. The balance sheet as of December 31, 2015 has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for annual consolidated financial statements. The accompanying unaudited condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2015 included in our Annual Report on Form 10-K, which was filed with the SEC on February 26, 2016 . Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Such management estimates include, but are not limited to, the best estimate of selling price for our products and services, commissions expense, future taxable income, contract manufacturer liabilities, litigation and settlement costs and other loss contingencies, fair value of our stock options and the purchase price allocation of acquired businesses. We base our estimates on historical experience and also on assumptions that we believe are reasonable. Changes in facts or circumstances may cause us to change our assumptions and estimates in future periods, and it is possible that actual results could differ from current or revised future estimates. Summary of Significant Accounting Policies There have been no significant changes to our significant accounting policies as of and for the three months ended March 31, 2016 , as compared to the significant accounting policies described in our Annual Report on Form 10-K for the year ended December 31, 2015 , except with respect to changes in our policy on Stock-Based Compensation. Stock-Based Compensation As permitted under ASU 2016-09, we have elected to recognize forfeitures as they occur, and no longer estimate a forfeiture rate when calculating the stock-based compensation for our equity awards. Recent Accounting Pronouncements In March 2016, the FASB issued ASU 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (Topic 718). This standard simplifies various aspects related to how share-based payments are accounted for and presented in the financial statements, including income taxes, forfeitures and statutory tax withholding requirements. The guidance is effective for us beginning in the first quarter of 2017. Early adoption is permitted. We elected to early adopt this standard in the current quarter. As a result of adopting this standard, we have made an accounting policy election to account for forfeitures as they occur. This change has been applied on a modified retrospective basis, resulting in a cumulative-effect adjustment to decrease retained earnings by $3.4 million as of January 1, 2016; the date of adoption. The adoption of this guidance also requires excess tax benefits and tax deficiencies be recorded in the income statement as opposed to additional paid-in capital when the awards vest or are settled. This change should be applied prospectively, and therefore our tax deficiencies of less than $0.1 million for the three months ended March 31, 2016 has been recorded as a component of our benefit from income taxes. The adoption of additional amendments related to the timing of when excess tax benefits are recognized and the accounting for minimum statutory withholding tax requirements included in this guidance has no impact on our current condensed consolidated financial statements or on any prior period financial statements presented. This guidance also requires changes in the classification of shares withheld to pay employee taxes and excess tax benefits on the consolidated statements of cash flows. The amendments require cash paid by an employer when directly withholding shares for tax-withholding purposes be classified as a financing activity, and be applied retrospectively to all prior periods presented. As these cash flows have previously been presented as financing activities, there is no change resulting from the adoption of this amendment. The amendments also require excess tax benefits be classified as an operating activity, consistent with other income tax cash flows, and may be applied either on a retrospective or prospective basis. We have elected to apply this amendment on a prospective basis, as there is no impact to our prior period consolidated statements of cash flows. As such, prior periods have not been adjusted. In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments (a consensus of the Emerging Issues Task Force). This standard clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. The guidance is effective for us beginning in the first quarter of 2017 and should be applied on a modified retrospective basis to existing debt instruments as of the beginning of the fiscal year for which the amendments are effective. Early adoption is permitted. As we previously assessed the embedded call (put) options associated with our Convertible Senior Notes in accordance with the requirements in this guidance, the adoption of this standard will have no impact on our consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This standard is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The guidance is effective for us beginning in the first quarter of 2019, and should be applied on a modified retrospective basis. Early adoption is permitted. We expect the adoption of this standard to have a material impact on our consolidated financial statements and related disclosures. In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. This standard eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Under this guidance, measurement-period adjustments will be recognized during the period in which they are determined. We adopted this standard in the current quarter and the adoption did not have a material impact on our consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). This standard provides a single model for revenue arising from contracts with customers and supersedes current revenue recognition guidance. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In July 2015, the FASB decided to defer the effective date by one year, and as a result, the guidance is effective for us beginning in the first quarter of 2018. Early adoption as of the original effective date would be permitted. The guidance permits companies to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net), and in April 2016, the FASB issued ASU No. 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing. These standards were issued to address implementation issues raised by the FASB-IASB Joint Transition Resource Group for Revenue Recognition (TRG). We are currently evaluating the impact the adoption of the new revenue guidance and related updates will have on our consolidated financial statements and related disclosures. In August 2014, the FASB issued ASU 2014-15, Disclosures of Uncertainties About an Entity’s Ability to Continue as a Going Concern. This standard provides guidance on how and when reporting entities must disclose going-concern uncertainties in their financial statements. The guidance is effective for us beginning in the first quarter of 2017. Early adoption is permitted. The adoption of this standard is not expected to have an impact on our consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The accounting guidance for fair value measurements provides a framework for measuring fair value on either a recurring or nonrecurring basis, whereby the inputs used in our valuation techniques are assigned a hierarchical level. The following are the three levels of inputs to measure fair value: • Level 1: Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. • Level 2: Inputs that reflect quoted prices for identical assets or liabilities in less active markets; quoted prices for similar assets or liabilities in active markets; benchmark yields, reported trades, broker/dealer quotes, inputs other than quoted prices that are observable for the assets or liabilities; or inputs that are derived principally from or corroborated by observable market data by correlation or other means. • Level 3: Unobservable inputs that reflect our own assumptions incorporated in valuation techniques used to measure fair value. These assumptions are required to be consistent with market participant assumptions that are reasonably available. We consider an active market to be one in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis, and consider an inactive market to be one in which there are infrequent or few transactions for the asset or liability, the prices are not current, or price quotations vary substantially either over time or among market makers. Where appropriate, our own or the counterparty’s non-performance risk is considered in measuring the fair values of assets. The following table presents our assets and liabilities measured at fair value on a recurring basis using the above input categories (in thousands): As of March 31, 2016 As of December 31, 2015 Description Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents: Money market funds $ 21,330 $ — $ — $ 21,330 $ 210,533 $ — $ — $ 210,533 Total cash equivalents 21,330 — — 21,330 210,533 — — 210,533 Short-term investments: Certificates of deposit — 17,254 — 17,254 — 19,124 — 19,124 Corporate notes and bonds — 443,250 — 443,250 — 447,267 — 447,267 U.S. Government agencies — 285,523 — 285,523 — 301,384 — 301,384 Total short-term investments — 746,027 — 746,027 — 767,775 — 767,775 Total assets measured at fair value $ 21,330 $ 746,027 $ — $ 767,357 $ 210,533 $ 767,775 $ — $ 978,308 Liabilities Contingent earn-out $ — $ — $ 35,588 $ 35,588 $ — $ — $ — $ — Total liabilities measured at fair value $ — $ — $ 35,588 $ 35,588 $ — $ — $ — $ — The estimated fair value of the contingent earn-out incurred in connection with our acquisition of iSIGHT is considered to be a Level 3 measurement due to the use of significant unobservable inputs. The value was determined using a discounted risk-adjusted expected (probability-weighted) cash flow methodology, by applying a real options approach model. The real options approach incorporated management's estimates of expected quarterly growth rates in bookings (ranging from 30% to 120% ), which could not be corroborated by observable market data, with the volatility of revenue for comparable companies ( 16.5% on average) and the correlation between comparable companies' quarterly revenue growth and that of the S&P 500 Index ( 44.7% on average), which are observable in the market, to determine the probability of achieving estimated bookings within the earn-out period of performance ( 2.5 years ). The resulting expected earn-out payment was discounted back to present value using our cost of debt (ranging from 6.3% to 7.1% ). We measure certain assets, including goodwill, intangible assets and our equity-method investment in a private company at fair value on a nonrecurring basis when there are identifiable events or changes in circumstances that may have a significant adverse impact on the fair value of these assets. No such events or changes occurred during the three months ended March 31, 2016 . The estimated fair value of the Convertible Senior Notes as of March 31, 2016 was determined to be $762.9 million , based on quoted market prices. We consider the fair value of the Convertible Senior Notes to be a Level 2 measurement as they are not actively traded.

Investments

Investments	3 Months Ended
	Mar. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Investments	Investments Our investments consisted of the following (in thousands): As of March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term investment Certificates of deposit $ 17,240 $ 15 $ (1 ) $ 17,254 $ 17,254 Corporate notes and bonds 443,240 257 (247 ) 443,250 443,250 U.S. Government agencies 285,609 41 (127 ) 285,523 285,523 Total $ 746,089 $ 313 $ (375 ) $ 746,027 $ 746,027 As of December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term investment Certificates of deposit $ 19,160 $ — $ (36 ) $ 19,124 $ 19,124 Corporate notes and bonds 448,688 — (1,421 ) 447,267 447,267 U.S. Government agencies 302,152 2 (770 ) 301,384 301,384 Total $ 770,000 $ 2 $ (2,227 ) $ 767,775 $ 767,775 The following tables present the gross unrealized losses and related fair values of our investments that have been in a continuous unrealized loss position (in thousands): As of March 31, 2016 Less Than 12 Months Greater Than 12 Months Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Certificates of deposit $ 1,159 $ (1 ) $ — $ — $ 1,159 $ (1 ) Corporate notes and bonds 256,480 (234 ) 15,974 (13 ) 272,454 (247 ) U.S. Government agencies 156,623 (125 ) 8,998 (2 ) 165,621 (127 ) Total $ 414,262 $ (360 ) $ 24,972 $ (15 ) $ 439,234 $ (375 ) As of December 31, 2015 Less Than 12 Months Greater Than 12 Months Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Certificates of deposit $ 18,404 $ (36 ) $ — $ — $ 18,404 $ (36 ) Corporate notes and bonds 430,466 (1,407 ) 16,801 (15 ) 447,267 (1,422 ) U.S. Government agencies 266,541 (761 ) 8,992 (8 ) 275,533 (769 ) Total $ 715,411 $ (2,204 ) $ 25,793 $ (23 ) $ 741,204 $ (2,227 ) Unrealized losses related to these investments are due to interest rate fluctuations as opposed to credit quality. In addition, we do not intend to sell, and it is not more likely than not that we would be required to sell, these investments before recovery of their cost basis. As a result, there is no other-than-temporary impairment for these investments as of March 31, 2016 and December 31, 2015 . The following table summarizes the contractual maturities of our investments at March 31, 2016 (in thousands): Amortized Cost Fair Value Due within one year $ 371,071 $ 370,962 Due within one to two years 375,018 375,065 Total $ 746,089 $ 746,027 All available-for-sale securities have been classified as current, based on management's intent and ability to use the funds in current operations. During 2015, we invested in a privately held company, obtaining an initial 12.5% ownership interest. This investment is accounted for under the equity method based on our ability to exercise significant influence over operating and financial policies of the investee, and is classified within deposits and other long-term assets on our condensed consolidated balance sheets. The carrying value of this investment was $1.6 million and $1.8 million as of March 31, 2016 and December 31, 2015 , respectively.

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment, net consisted of the following (in thousands): As of March 31, 2016 As of December 31, 2015 Computer equipment and software $ 132,862 $ 120,886 Leasehold improvements 43,901 41,626 Furniture and fixtures 14,314 13,470 Machinery and equipment 447 447 Total property and equipment 191,524 176,429 Less: accumulated depreciation (110,200 ) (98,061 ) Total property and equipment, net $ 81,324 $ 78,368 Depreciation and amortization expense related to property and equipment and demonstration units during the three months ended March 31, 2016 and 2015 was $14.1 million and $14.3 million , respectively.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2016
Business Combinations [Abstract]
Business Combinations	Business Combinations Acquisition of iSIGHT On January 14, 2016, we acquired all of the outstanding shares of privately held iSIGHT, one of the world’s leading providers of cyber threat intelligence for global enterprises. The acquisition extends our intelligence network to create an advanced and comprehensive private cyber threat intelligence operation, providing customers with higher fidelity alerts, context to prioritize threats and the strategic insights to proactively prepare for threats that might target their industry or region. In connection with this acquisition, we paid upfront cash consideration of $192.8 million , incurred liabilities of $35.6 million contingent upon the achievement of a threat intelligence bookings target on or before the end of the second quarter of 2018, and issued 1,793,305 shares of our common stock with an estimated fair value of $28.2 million , which will be released to former stockholders of iSIGHT upon the achievement of the same threat intelligence bookings target stated above. This resulted in total purchase consideration of $256.6 million . The number of shares was fixed at the completion of the acquisition and is the maximum number of shares that can be released. The contingent earn-out liability of $35.6 million is included in accrued compensation on the condensed consolidated balance sheet as of March 31, 2016 , and will result in a cash payment of $41.3 million , if and when the threat intelligence bookings target is achieved. The acquisition of iSIGHT was accounted for in accordance with the acquisition method of accounting for business combinations with FireEye as the accounting acquirer. We expensed the related acquisition costs of $1.9 million in general and administrative expenses. We also assumed and paid liabilities of $7.0 million for transaction costs incurred by iSIGHT prior to acquisition, which were accounted for separate from consideration transferred. Under the acquisition method of accounting, the total purchase consideration is allocated to the tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values. The total purchase price of $256.6 million was allocated using information currently available to us. As a result, we may continue to adjust the preliminary purchase price allocation after obtaining more information regarding asset valuations, liabilities assumed, and revisions of preliminary estimates. Allocation of the preliminary purchase price is as follows (in thousands): Amount Net tangible liabilities assumed $ (18,366 ) Intangible assets 82,800 Deferred tax liability (10,328 ) Goodwill 202,532 Total preliminary purchase price allocation $ 256,638 The preliminary purchase price exceeded the fair value of the net tangible and identifiable intangible assets acquired, resulting in the recognition of goodwill. Goodwill is primarily attributable to expected synergies in our subscription offerings and cross-selling opportunities. None of the goodwill is expected to be deductible for U.S. federal income tax purposes. Intangible assets consist primarily of customer relationships, content, developed technology and other intangible assets. Customer relationship intangibles relate to iSIGHT's ability to sell current and future content, as well as products built around this content, to its existing customers. Content intangibles represent threat intelligence data gathered through the analysis of cyber-crimes, cyber-attacks, hacking, and cyber criminals. Intangible assets attributable to developed technology include a combination of patented and unpatented technology, trade secrets, computer software and research processes that represent the foundation for the existing and planned new products to facilitate the generation of new content. The estimated useful life and fair values of the identifiable intangible assets are as follows (in thousands): Preliminary Estimated Useful Life (in years) Amount Customer relationships 8 $ 32,600 Content 4 28,900 Developed technology 4-6 17,100 Trade name 5 3,100 Non-competition agreements 2 1,100 Total identifiable intangible assets $ 82,800 The value of customer relationships and content was estimated using the excess earnings method, an income approach (Level 3), which converts projected revenues and costs into cash flows. To reflect the fact that certain other assets contribute to the cash flows generated, the returns for these contributory assets were removed to arrive at estimated cash flows solely attributable to the customer relationships and content, which were discounted at rates of 15% and 14% , respectively. The value of developed technology and the trade name was estimated using the relief-from-royalty method, an income approach (Level 3), which estimates the cost savings that accrue to the owner of the intangibles asset that would otherwise be payable as royalties or license fees on revenues earned through the use of the asset. A royalty rate is applied to the projected revenues associated with the intangible asset to determine the amount of savings, which is then discounted to determine the fair value. The developed technology and trade name were valued using royalty rates of 10% and 1% , respectively, and discounted at rates of 14% and 15% , respectively. The results of operations of iSIGHT have been included in our condensed consolidated statements of operations from the acquisition date, and contributed $9.4 million to our consolidated revenues and $2.3 million to our consolidated net loss during the three months ended March 31, 2016 . Pro forma results of operations have not been presented because the acquisition was not material to our results of operations. Acquisition of Invotas On February 1, 2016, we acquired all of the outstanding shares of privately held Invotas, a provider of security automation and orchestration technology. This acquisition enables us to deliver a premier security orchestration capability as part of our global threat management platform to unify cyber attack detection results, threat intelligence and incident response elements of an organization’s security program into a single console, giving enterprises the ability to respond more quickly to attacks through automation. In connection with this acquisition, we paid upfront cash consideration of $17.7 million and issued 742,026 shares of our common stock with an estimated fair value of $11.1 million . This resulted in total purchase consideration of $28.8 million . Additionally, we replaced unvested option awards with grants of 95,614 restricted stock units which will vest over the requisite service period of four years, and granted an additional 1,002,748 restricted stock units which will vest upon the achievement of stated performance milestones over a period of approximately three years, subject to continuing service during that time. These awards are being recognized as operating expense over the requisite service periods as they relate to post-combination services. The acquisition of Invotas was accounted for in accordance with the acquisition method of accounting for business combinations with FireEye as the accounting acquirer. We expensed the related acquisition costs of $0.5 million in general and administrative expenses. We also assumed and paid liabilities of $0.7 million for transaction costs incurred by Invotas prior to acquisition, which were accounted for separate from consideration transferred. Under the acquisition method of accounting, the total purchase consideration is allocated to the tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values. The total purchase price of $28.8 million was allocated using information currently available to us. As a result, we may continue to adjust the preliminary purchase price allocation after obtaining more information regarding asset valuations, liabilities assumed, and revisions of preliminary estimates. Allocation of the preliminary purchase price is as follows (in thousands): Amount Net tangible liabilities assumed $ (306 ) Intangible assets 8,400 Deferred tax liability (703 ) Goodwill 21,364 Total preliminary purchase price allocation $ 28,755 The preliminary purchase price exceeded the fair value of the net tangible and identifiable intangible assets acquired, resulting in the recognition of goodwill. Goodwill is primarily attributable to increased selling opportunities. None of the goodwill is expected to be deductible for U.S. federal income tax purposes. Intangible assets consist primarily of developed technology, in-process research and development and other intangible assets. Developed technology intangibles include a combination of patented and unpatented technology, trade secrets, computer software and research processes that represent the foundation for the existing and planned new product offerings. The in-process research and development intangible represents the estimated fair value of acquired research projects which had not reached technological feasibility at acquisition date, but have since been developed into products. The estimated useful life and fair values of the identifiable intangible assets are as follows (in thousands): Preliminary Estimated Useful Life (in years) Amount Developed technology 4 $ 4,500 In-process research and development N/A 2,800 Customer relationships 10 800 Non-competition agreements 3 300 Total identifiable intangible assets $ 8,400 The value of developed technology and in-process research and development (IPR&D) was estimated using the excess earnings method, an income approach (Level 3), which converts projected revenues and costs into cash flows. To reflect that fact that certain other assets contribute to the cash flows generated, the returns for these contributory assets were removed to arrive at estimated cash flows solely attributable to the developed technology and IPR&D, which were discounted at rates of 16% and 17.3% , respectively. The results of operations of Invotas have been included in our condensed consolidated statements of operations from the acquisition date, although such results did not have a material impact on our consolidated revenues or net loss during the three months ended March 31, 2016 . Pro forma results of operations have not been presented because the acquisition was not material to our results of operations. Goodwill and Purchased Intangible Assets Changes in the carrying amount of goodwill for the three months ended March 31, 2016 are as follows (in thousands): Amount Balance as of December 31, 2015 $ 750,288 Goodwill acquired 223,896 Balance as of March 31, 2016 $ 974,184 Purchased intangible assets consisted of the following as of the dates below (in thousands): As of March 31, 2016 As of December 31, 2015 Developed technology $ 99,793 $ 78,193 Content 157,500 128,600 Customer relationships 108,700 75,300 Contract backlog 12,500 12,500 Trade names 15,500 12,400 Non-competition agreements 1,400 — Total intangible assets subject to amortization 395,393 306,993 Less: accumulated amortization (107,598 ) (92,433 ) Net intangible assets subject to amortization 287,795 214,560 In-process research and development 2,800 — Total net intangible assets $ 290,595 $ 214,560 Amortization expense of intangible assets for the three months ended March 31, 2016 and 2015 was $15.2 million and $11.8 million , respectively. The expected annual amortization expense of intangible assets as of March 31, 2016 is presented below (in thousands): Years Ending December 31, Amount 2016 (remaining nine months) $ 47,401 2017 57,378 2018 45,694 2019 43,808 2020 30,186 2021 and thereafter 63,328 Total intangible assets subject to amortization 287,795 Total intangible assets with indefinite lives 2,800 Total $ 290,595

Restructuring Charges

Restructuring Charges	3 Months Ended
	Mar. 31, 2016
Restructuring and Related Activities [Abstract]
Restructuring Charges	Restructuring Charges In addition to our restructuring plans initiated in August 2014, we initiated a series of business restructuring plans beginning in February 2016 to reduce our cost structure and improve efficiency, resulting in workforce reductions and the consolidation of certain real estate facilities. The following table sets forth a summary of restructuring activities during the three months ended March 31, 2016 (in thousands): Severance and related costs Facilities costs Total costs Balance, December 31, 2015 $ — $ 217 $ 217 Provision for restructuring charges 1,390 280 1,670 Cash payments (984 ) (344 ) (1,328 ) Other adjustments — 324 324 Balance, March 31, 2016 $ 406 $ 477 $ 883 The remaining restructuring balance of $0.9 million at March 31, 2016 is composed of $0.4 million of severance payments which we expect to pay during the second quarter of 2016, and $0.5 million of non-cancelable lease costs which we expect to pay over the terms of the related obligations through the second quarter of 2020, less estimated sublease income.

Deferred Revenue

Deferred Revenue	3 Months Ended
	Mar. 31, 2016
Revenue Recognition [Abstract]
Deferred Revenue	Deferred Revenue Deferred revenue consisted of the following as of the dates below (in thousands): As of March 31, 2016 As of December 31, 2015 Product, current $ 8,083 $ 8,200 Subscription and services, current 321,012 296,969 Total deferred revenue, current 329,095 305,169 Product, non-current 3,231 3,051 Subscription and services, non-current 233,756 218,778 Total deferred revenue, non-current 236,987 221,829 Total deferred revenue $ 566,082 $ 526,998 For the three months ended March 31, 2016 , deferred revenue includes $21.1 million assumed in connection with acquisitions.

Convertible Senior Notes

Convertible Senior Notes	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Convertible Senior Notes	Convertible Senior Notes Convertible Senior Notes In June 2015, we issued $460.0 million principal amount of Series A Notes and $460.0 million principal amount of Series B Notes, including the full exercise of the initial purchasers' over-allotment option, in a private placement to qualified institutional purchasers pursuant to an exemption from registration provided by Section 4(a)(2) and Rule 144A under the Securities Act. The net proceeds after the initial purchasers' discount of $23.0 million and issuance costs of $0.5 million from the Convertible Senior Notes were $896.5 million . The Series A Notes and Series B Notes bear interest at 1.000% per year and 1.625% per year, respectively, payable semiannually in arrears on June 1 and December 1 of each year, beginning December 1, 2015. The Convertible Senior Notes mature on June 1, 2035, unless earlier repurchased, redeemed or converted. The Convertible Senior Notes are unsecured obligations and rank senior in right of payment to any of our indebtedness that is expressly subordinated in right of payment to the Convertible Senior Notes. They rank equally in right of payment with all of our existing and future liabilities that are not expressly subordinated to the Convertible Senior Notes and effectively rank junior in right of payment to any of our secured indebtedness to the extent of the value of the assets securing such indebtedness. They are structurally junior to all indebtedness and other liabilities (including trade payables) of our subsidiaries. The Convertible Senior Notes do not contain any financial covenants and do not restrict us from paying dividends or issuing or repurchasing our other securities. The initial conversion rate on each series of Convertible Senior Notes is 16.4572 shares of our common stock per $1,000 principal amount of Convertible Senior Notes, which is equivalent to an initial conversion price of approximately $60.76 per share of common stock. The conversion rate of each series of Convertible Senior Notes may be adjusted upon the occurrence of certain specified events, but not for accrued and unpaid interest. Holders may convert the Convertible Senior Notes at their option in multiples of $1,000 principal amount prior to March 1, 2035, excluding the period from March 1, 2020 to June 1, 2020 in the case of the Series A Notes and March 1, 2022 to June 1, 2022 in the case of the Series B Notes, only under the following circumstances: • during any calendar quarter commencing after the calendar quarter ended on September 30, 2015 (and only during such calendar quarter), if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price for the Convertible Senior Notes of the relevant series on each applicable trading day; • during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of Series A Notes or Series B Notes, as applicable, for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate for the notes of the relevant series on each such trading day; • if we call any or all of the Convertible Senior Notes of a series for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the relevant redemption date; or • upon the occurrence of specified corporate events, as specified in each indenture governing the Convertible Senior Notes. Regardless of the foregoing conditions, holders may convert their Convertible Senior Notes at their option in multiples of $1,000 principal amount at any time during the period from March 1, 2020 to June 1, 2020 in the case of the Series A Notes and during the period from March 1, 2022 to June 1, 2022 in the case of the Series B Notes, or after March 1, 2035 until maturity for either series of Convertible Senior Notes. Upon conversion, the Convertible Senior Notes can be settled in cash, shares of our common stock or any combination thereof at our option. We may be required by holders of the Convertible Senior Notes to repurchase all or any portion of their Convertible Senior Notes at 100% of the principal amount plus accrued and unpaid interest, on each of June 1, 2020, June 1, 2025 and June 1, 2030, in the case of the Series A Notes, and each of June 1, 2022, June 1, 2025 and June 1, 2030 in the case of the Series B Notes. Holders may also require us to repurchase the Convertible Senior Notes if we undergo a "fundamental change," as defined in each indenture governing the Convertible Senior Notes, at a purchase price equal to 100% of the principal amount, plus accrued and unpaid interest. Additionally, we may redeem for cash all or any portion of the Series B Notes on or after June 1, 2020 until June 1, 2022 if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending not more than three trading days immediately preceding the date we provide notice of redemption. We also may redeem for cash all or any portion of the Series A Notes on or after June 1, 2020 until maturity and all or any portion of the Series B Notes on or after June 1, 2022 until maturity, regardless of the foregoing sale price condition. In accordance with accounting for debt with conversions and other options, we allocated the principal amount of the Convertible Senior Notes into liability and equity components. We also allocated the total amount of initial purchasers' discount and transaction costs incurred to the liability and equity components using the same proportions as the proceeds from the Convertible Senior Notes. Transaction costs of $0.4 million and $0.1 million and initial purchasers' discount of $17.6 million and $5.4 million were attributable to the liability component and equity component of the Convertible Senior Notes, respectively. The liability and equity components of the Convertible Senior Notes consisted of the following (in thousands): As of March 31, 2016 As of December 31, 2015 Series A Notes Series B Notes Series A Notes Series B Notes Liability component: Principal $ 460,000 $ 460,000 $ 460,000 $ 460,000 Less: Convertible senior notes discounts and issuance costs, net of amortization (88,726 ) (116,296 ) (93,469 ) (120,333 ) Net carrying amount $ 371,274 $ 343,704 $ 366,531 $ 339,667 Equity component, net of issuance costs $ 92,567 $ 117,834 $ 92,567 $ 117,834 The unamortized discounts and issuance costs as of March 31, 2016 will be amortized over a weighted-average remaining period of approximately five years. Interest expense related to the Convertible Senior Notes consisted of the following (in thousands): Three Months Ended March 31, 2016 Series A Notes Series B Notes Coupon interest $ 1,150 $ 1,869 Amortization of convertible senior notes discounts and issuance costs 4,743 4,037 Total interest expense recognized $ 5,893 $ 5,906 Effective interest rate on the liability component 6.4 % 7.0 % Prepaid Forward Stock Purchase In connection with the issuance of the Convertible Senior Notes, we also entered into privately negotiated Prepaid Forwards with one of the initial purchasers of the Convertible Senior Notes (the “Forward Counterparty”), pursuant to which we paid approximately $150.0 million . The amount prepaid is equivalent to approximately 3.3 million shares which are to be settled on or around June 1, 2020 and June 1, 2022, respectively, subject to any early settlement, in whole or in part, of each Prepaid Forward. The Prepaid Forwards are intended to facilitate privately negotiated derivative transactions by which investors in the Convertible Senior Notes will be able to hedge their investment in the Convertible Senior Notes. In the event we pay any cash dividends on our common stock, the Forward Counterparty will pay an equivalent amount back to us. The related shares were accounted for as a repurchase of common stock, and are presented as Treasury Stock in the unaudited condensed consolidated balance sheets. The 3.3 million shares of common stock purchased under the Prepaid Forwards are excluded from weighted-average shares outstanding for basic and diluted EPS purposes although they remain legally outstanding.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases We lease our facilities under various non-cancelable operating leases, which expire on various dates through the year ending December 31, 2024. Rent expense is recognized using the straight-line method over the term of the lease. Rent expense, net of sublease income, was $3.6 million and $3.2 million for the three months ended March 31, 2016 and 2015 , respectively. The aggregate future non-cancelable minimum rental payments on our operating leases, as of March 31, 2016 , are as follows (in thousands): Years Ending December 31, Amount 2016 (remaining nine months) $ 11,509 2017 13,754 2018 8,137 2019 5,616 2020 5,167 2021 and thereafter 7,092 Total $ 51,275 Total future non-cancelable minimum rental payments have not been reduced by future minimum sublease rentals totaling $1.0 million . We are party to letters of credit totaling $1.2 million as of March 31, 2016 and December 31, 2015 , issued primarily in support of operating leases at several of our facilities. These letters of credit are collateralized by a line with our bank. No amounts have been drawn against these letters of credit. Contract Manufacturer Commitments Our independent contract manufacturers procure components and assemble our products based on our forecasts. These forecasts are based on estimates of future demand for our products, which are in turn based on historical trends and an analysis from our sales and product marketing organizations, adjusted for overall market conditions. In order to reduce manufacturing lead times and plan for adequate supply, we may issue forecasts and orders for components and products that are non-cancelable. As of March 31, 2016 and December 31, 2015 , we had non-cancelable open orders of $14.2 million and $16.9 million , respectively. We are required to record a liability for firm, non-cancelable and unconditional purchase commitments with contract manufacturers and suppliers for quantities in excess of our future demand forecasts. As of March 31, 2016 we have not accrued any significant costs for such non-cancelable commitments. Purchase Obligations As of March 31, 2016 , we had approximately $30.8 million of non-cancelable firm purchase commitments primarily for purchases of software and services. In those situations in which we have received delivery of the goods or services as of March 31, 2016 under purchase orders outstanding as of the same date, such amounts are reflected in the condensed consolidated balance sheet as accounts payable or accrued liabilities, and are excluded from the $30.8 million . Litigation We accrue for contingencies when we believe that a loss is probable and that we can reasonably estimate the amount of any such loss. We have made an assessment of the probability of incurring any such losses and whether or not those losses are estimable. On June 20, 2014, a purported stockholder class action lawsuit was filed in the Superior Court of California, County of Santa Clara, against the Company, current and former members of our Board of Directors, current and former officers, and the underwriters of our March 2014 follow-on public offering. On July 17, 2014, a substantially similar lawsuit was filed in the same court against the same defendants. The actions were consolidated and, on March 4, 2015, an amended complaint was filed, alleging violations of the federal securities laws on behalf of a purported class consisting of purchasers of the Company's common stock pursuant or traceable to the registration statement and prospectus for the follow-on public offering, and seeking unspecified compensatory damages and other relief. On April 20, 2015, defendants filed demurrers seeking that the amended complaint be dismissed. On August 11, 2015, the court overruled defendants' demurrers. On November 16, 2015, plaintiffs filed a motion seeking certification of the putative class, currently scheduled for a hearing on May 13, 2016. On January 6, 2016, the Company and the individual defendants filed a motion for judgment on the pleadings seeking that the action be dismissed for lack of subject-matter jurisdiction, which was denied by the court on April 1, 2016. The Company intends to defend the litigation vigorously. Based on information currently available, the Company has determined that the amount of any possible loss or range of possible loss is not reasonably estimable. On November 24, 2014, a purported stockholder class action lawsuit was filed in the United States District Court for the Northern District of California against the Company and certain of its officers. On June 29, 2015, plaintiffs filed a consolidated complaint alleging violations of the federal securities laws on behalf of a putative class of all persons who purchased or otherwise acquired the Company’s securities between January 2, 2014, and November 4, 2014. Plaintiffs seek, among other things, compensatory damages and attorneys’ fees and costs on behalf of the putative class. On August 21, 2015, defendants filed a motion to dismiss, which was heard on November 12, 2015. No ruling has been issued on the motion. The Company intends to defend the litigation vigorously. Based on information currently available, the Company has determined that the amount of any possible loss or range of possible loss is not reasonably estimable. On January 28, 2015, certain of the Company’s officers and directors were named as defendants in a putative derivative action filed in the Superior Court of California, County of Santa Clara. On April 21, 2015, a substantially similar lawsuit was filed in the same court against the same defendants. The Company is named as a nominal defendant in both actions. The actions were consolidated and a consolidated complaint was filed on June 15, 2015, purporting to allege claims for breach of fiduciary duty and unjust enrichment. On July 15, 2015, defendants filed demurrers to the consolidated complaint. On December 4, 2015, the court sustained, with leave to amend, defendants’ demurrers on the basis that plaintiffs had failed adequately to allege derivative standing. Plaintiffs filed an amended complaint on May 3, 2016. Based on information currently available, the Company has determined that the amount of any possible loss or range of possible loss is not reasonably estimable. On December 15, 2015, a lawsuit was filed in the Delaware Court of Chancery by a purported stockholder against the Company, seeking production of certain books and records pursuant to Delaware law. The action was dismissed with prejudice on April 25, 2016. In February 2016, a lawsuit was filed in the Superior Court of California, County of Santa Clara, by one of the plaintiffs in the aforementioned putative derivative action against the Company, seeking production of certain books and records pursuant to Delaware and California law. At a hearing on May 3, 2016, the court indicated that it would adopt a tentative ruling sustaining the Company's demurrer to the petition and dismissing the action. We are also subject to legal proceedings, claims and litigation, including intellectual property litigation, arising in the ordinary course of business. Such matters are subject to many uncertainties and outcomes, and are not predictable with assurance. To the extent there is a reasonable possibility that a loss exceeding amounts already recognized may be incurred, and the amount of such additional loss would be material, we will either disclose the estimated additional loss or state that such an estimate cannot be made. We do not currently believe that it is reasonably possible that additional losses in connection with litigation arising in the ordinary course of business would be material. Indemnification Under the indemnification provisions of our standard sales related contracts, we agree to defend our customers against third-party claims asserting infringement of certain intellectual property rights, which may include patents, copyrights, trademarks, or trade secrets, and to pay judgments entered on such claims. Our exposure under these indemnification provisions is generally limited to the total amount paid by our customer under the agreement. However, certain agreements include indemnification provisions that could potentially expose us to losses in excess of the amount received under the agreement. In addition, we indemnify our officers, directors, and certain key employees for actions taken while they are or were serving in good faith in such capacities. Through March 31, 2016 , there have been no claims under any indemnification provisions.

Common Shares Reserved for Issu

Common Shares Reserved for Issuance	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Common Shares Reserved for Issuance	Common Shares Reserved for Issuance We have 100,000,000 shares of convertible preferred stock with a par value of $0.0001 per share authorized, none of which were issued and outstanding as of March 31, 2016 or December 31, 2015 . Under our amended and restated certificate of incorporation, we are authorized to issue 1,000,000,000 shares of common stock with a par value of $0.0001 per share as of March 31, 2016 and December 31, 2015 . Each share of common stock outstanding is entitled to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the Board of Directors, subject to the prior rights of holders of all classes of convertible preferred stock outstanding. We had reserved shares of common stock for issuance as follows (in thousands): As of March 31, 2016 As of December 31, 2015 Reserved under stock award plans 44,443 38,500 Convertible Senior Notes 15,141 15,141 ESPP 4,830 3,214 Total 64,414 56,855

Equity Award Plans

Equity Award Plans	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Award Plans	Equity Award Plans We have operated under our 2013 Equity Incentive Plan ("2013 Plan") since our initial public offering ("IPO") in September 2013. Our 2013 Plan provides for the issuance of restricted stock and the granting of options, stock appreciation rights, performance shares, performance units and restricted stock units to our employees, officers, directors and consultants. Awards granted under the 2013 Plan vest over the periods determined by the Board of Directors or compensation committee of the Board of Directors, generally four years, and stock options granted under the 2013 Plan expire no more than ten years after the date of grant. In the case of an incentive stock option granted to an employee who at the time of grant owns stock representing more than 10% of the total combined voting power of all classes of stock, the exercise price shall be no less than 110% of the fair value per share on the date of grant, and the award shall expire five years from the date of grant. For options granted to any other employee, the per share exercise price shall be no less than 100% of the fair value per share on the date of grant. In the case of non-statutory stock options and options granted to consultants, the per share exercise price shall be no less than 100% of the fair value per share on the date of grant. Stock that is purchased prior to vesting is subject to our right of repurchase at any time following termination of the participant's service for so long as such stock remains unvested. Approximately 10.1 million shares and 7.2 million shares of our common stock were reserved for future grants as of March 31, 2016 and December 31, 2015 , respectively, under the 2013 Plan . Our 2013 Employee Stock Purchase Plan ("ESPP") allows eligible employees to acquire shares of our common stock at 85% of the lower of the fair market value of our common stock on the first trading day of each offering period or on the exercise date. Our ESPP provides for annual increases in the number of shares available for issuance on the first day of each fiscal year. An aggregate of 4,830,720 shares and 3,214,287 shares of common stock were available for future issuance as of March 31, 2016 and December 31, 2015 , respectively, under our ESPP. From time to time, we also grant restricted common stock or restricted stock awards outside of our equity incentive plans to certain employees in connection with acquisitions. Stock Option Activity A summary of the activity for our stock option changes during the reporting period and a summary of information related to options vested and options exercisable are presented below (in thousands, except per share amounts and contractual life years): Options Outstanding Number of Shares Weighted- Average Exercise Price Weighted- Average Grant Date Fair Value (per share) Weighted- Aggregate Intrinsic Value Balance — December 31, 2015 11,494 $ 10.67 6.9 $ 149,157 Granted — — $ — Exercised (601 ) 4.73 7,063 Cancelled (266 ) 16.99 Balance — March 31, 2016 10,627 $ 10.84 6.5 $ 110,382 Options exercisable — March 31, 2016 7,466 $ 9.28 6.2 $ 84,211 Restricted Stock Award (RSA) and Restricted Stock Unit (RSU) Activity A summary of the activity for our restricted common stock, RSAs and RSUs during the reporting period and a summary of information related to unvested restricted common stock, RSAs and RSUs and those expected to vest based on the achievement of a performance condition are presented below (in thousands, except per share amounts and contractual life years): Number of Weighted- Weighted- Aggregate Unvested balance — December 31, 2015 20,054 $ 33.68 1.6 $ 415,912 Granted 6,496 12.56 Vested (1,475 ) 40.45 Cancelled (1,179 ) 34.29 Unvested balance — March 31, 2016 23,896 $ 26.82 1.6 $ 429,886 Unvested awards for which the requisite service period has not been rendered but that are expected to vest based on the achievement of a performance condition — March 31, 2016 7,030 $ 21.49 1.6 $ 126,465 Included in the approximately 6.5 million shares granted in the table above are 3.6 million shares granted to employees in connection with acquisitions. Stock-Based Compensation We record stock-based compensation based on the fair value of stock options on grant date using the Black-Scholes option-pricing model. We determine the fair value of shares of common stock to be issued under the ESPP using the Black-Scholes option-pricing model. The fair value of restricted stock units and restricted stock awards equals the market value of the underlying stock on the date of grant. We grant performance-based restricted stock units and restricted stock awards to certain employees which vest upon the achievement of certain performance conditions, subject to the employees’ continued service relationship with us. We assess the probability of vesting at each reporting period and adjust our compensation cost based on this probability assessment. We recognize such compensation expense on a straight-line basis over the service provider’s requisite service period. Stock-based compensation expense related to stock options, ESPP and restricted stock units and awards is included in the condensed consolidated statements of operations as follows (in thousands): Three Months Ended March 31, 2016 2015 Cost of product revenue $ 667 $ 268 Cost of subscription and services revenue 9,601 6,378 Research and development 24,430 16,035 Sales and marketing 16,154 16,454 General and administrative 13,215 10,740 Total $ 64,067 $ 49,875 As of March 31, 2016 , total compensation cost related to stock-based awards not yet recognized was $527.7 million , which is expected to be amortized on a straight-line basis over the weighted-average remaining vesting period of approximately three years.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We account for income taxes under the asset and liability method. Under this method, deferred income tax assets and liabilities are determined based upon the difference between the financial statement carrying amounts and the tax basis of assets and liabilities and are measured using the enacted tax rate expected to apply to taxable income in the years in which the differences are expected to be reversed. We recognized a benefit from income taxes of $10.0 million for the three months ended March 31, 2016 and a provision for income taxes of $1.0 million for the three months ended March 31, 2015 . The tax benefit for the three months ended March 31, 2016 is primarily due to the release of the U.S. valuation allowance on the U.S. deferred tax assets resulting from recording a deferred tax liability on the acquisition-related intangibles for which no benefit will be derived, partially offset by foreign and state income taxes. The tax provision for the three months ended March 31, 2015 is primarily due to foreign and state income taxes.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share Basic net loss per share is calculated by dividing net loss by the weighted average number of common shares outstanding during the period, less shares subject to repurchase, and excludes any dilutive effects of employee share based awards and warrants. Diluted net income per common share is computed giving effect to all potentially dilutive common shares, including common stock issuable upon exercise of stock options, conversion of the Convertible Senior Notes, and unvested restricted common stock and stock units. As we had net losses for the three months ended March 31, 2016 and 2015 , all potential common shares were determined to be anti-dilutive. The following table sets forth the computation of net loss per common share (in thousands, except per share amounts): Three Months Ended March 31, 2016 2015 Numerator: Net loss $ (155,900 ) $ (133,964 ) Denominator: Weighted average number of shares outstanding—basic and diluted 158,781 151,651 Net loss per share—basic and diluted $ (0.98 ) $ (0.88 ) The following outstanding options and unvested shares were excluded (as common stock equivalents) from the computation of diluted net loss per common share for the periods presented as their effect would have been anti-dilutive (in thousands): As of March 31, 2016 2015 Options to purchase common stock 10,627 15,403 Unvested early exercised common shares 647 1,959 Unvested restricted stock awards and units 23,896 9,936 Convertible senior notes 15,141 — ESPP shares 667 312

Employee Benefit Plan

Employee Benefit Plan	3 Months Ended
	Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plan	Employee Benefit Plan 401(k) Plan We have established a 401(k) tax-deferred savings plan (the “401(k) Plan”) which permits participants to make contributions by salary deduction pursuant to Section 401(k) of the Internal Revenue Code of 1986, as amended. All participants’ interests in their deferrals are 100% vested when contributed. We are responsible for administrative costs of the 401(k) Plan and have made no matching contributions into our 401(k) Plan since inception. Under the 401(k) Plan, pre-tax contributions are allocated to each participant’s individual account and are then invested in selected investment alternatives according to the participants’ directions. The 401(k) Plan is intended to qualify under Sections 401(a) and 501(a) of the Code. As a tax-qualified retirement plan, contributions to the 401(k) Plan and earnings on those contributions are not taxable to the employees until distributed, and all contributions are deductible by us when made.

Segment and Major Customers Inf

Segment and Major Customers Information	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Segment and Major Customers Information	Segment and Major Customers Information We conduct business globally and are primarily managed on a geographic basis. Our Chief Executive Officer, who is our chief operating decision maker, reviews financial information presented on a consolidated basis accompanied by information about revenue by geographic region for purposes of allocating resources and evaluating financial performance. There are no segment managers who are held accountable for operations, operating results, and plans for levels, components, or types of products or services below the consolidated unit level. Accordingly, we are considered to be in a single reportable segment and operating unit structure. Revenue by geographic region based on the billing address is as follows (in thousands): Three Months Ended March 31, 2016 2015 Revenue: United States $ 115,852 $ 89,189 EMEA 24,442 16,792 APAC 21,823 13,721 Other 5,849 5,668 Total revenue $ 167,966 $ 125,370 Long lived assets by geographic region based on physical location is as follows (in thousands): As of March 31, 2016 As of December 31, 2015 Property and Equipment, net: United States $ 58,099 $ 57,537 International 23,225 20,831 Total property and equipment, net $ 81,324 $ 78,368 For the three months ended March 31, 2016 , one distributor represented 17% and one reseller represented 11% of the Company's total revenue. For the three months ended March 31, 2015 , one distributor represented 13% and one reseller represented 11% of the Company's total revenue. As of March 31, 2016 , no customer represented 10% or more of the Company's net accounts receivable balance. As of December 31, 2015 , two distributors represented 20% and 12% , respectively, of the Company's net accounts receivable balance.

Description of Business and S22

Description of Business and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Consolidation	The accompanying unaudited condensed consolidated financial statements include the accounts of FireEye, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”), and following the requirements of the Securities and Exchange Commission (“SEC”), for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. These unaudited condensed consolidated financial statements have been prepared on the same basis as our annual consolidated financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, that are necessary for a fair statement of our financial information. The results of operations for the three months ended March 31, 2016 are not necessarily indicative of the results to be expected for the year ending December 31, 2016 or for any other interim period or for any other future year. The balance sheet as of December 31, 2015 has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for annual consolidated financial statements. The accompanying unaudited condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2015 included in our Annual Report on Form 10-K, which was filed with the SEC on February 26, 2016 .
Use of Estimates	The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Such management estimates include, but are not limited to, the best estimate of selling price for our products and services, commissions expense, future taxable income, contract manufacturer liabilities, litigation and settlement costs and other loss contingencies, fair value of our stock options and the purchase price allocation of acquired businesses. We base our estimates on historical experience and also on assumptions that we believe are reasonable. Changes in facts or circumstances may cause us to change our assumptions and estimates in future periods, and it is possible that actual results could differ from current or revised future estimates.
Stock-Based Compensation	As permitted under ASU 2016-09, we have elected to recognize forfeitures as they occur, and no longer estimate a forfeiture rate when calculating the stock-based compensation for our equity awards.
Recent Accounting Pronouncements	In March 2016, the FASB issued ASU 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (Topic 718). This standard simplifies various aspects related to how share-based payments are accounted for and presented in the financial statements, including income taxes, forfeitures and statutory tax withholding requirements. The guidance is effective for us beginning in the first quarter of 2017. Early adoption is permitted. We elected to early adopt this standard in the current quarter. As a result of adopting this standard, we have made an accounting policy election to account for forfeitures as they occur. This change has been applied on a modified retrospective basis, resulting in a cumulative-effect adjustment to decrease retained earnings by $3.4 million as of January 1, 2016; the date of adoption. The adoption of this guidance also requires excess tax benefits and tax deficiencies be recorded in the income statement as opposed to additional paid-in capital when the awards vest or are settled. This change should be applied prospectively, and therefore our tax deficiencies of less than $0.1 million for the three months ended March 31, 2016 has been recorded as a component of our benefit from income taxes. The adoption of additional amendments related to the timing of when excess tax benefits are recognized and the accounting for minimum statutory withholding tax requirements included in this guidance has no impact on our current condensed consolidated financial statements or on any prior period financial statements presented. This guidance also requires changes in the classification of shares withheld to pay employee taxes and excess tax benefits on the consolidated statements of cash flows. The amendments require cash paid by an employer when directly withholding shares for tax-withholding purposes be classified as a financing activity, and be applied retrospectively to all prior periods presented. As these cash flows have previously been presented as financing activities, there is no change resulting from the adoption of this amendment. The amendments also require excess tax benefits be classified as an operating activity, consistent with other income tax cash flows, and may be applied either on a retrospective or prospective basis. We have elected to apply this amendment on a prospective basis, as there is no impact to our prior period consolidated statements of cash flows. As such, prior periods have not been adjusted. In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments (a consensus of the Emerging Issues Task Force). This standard clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. The guidance is effective for us beginning in the first quarter of 2017 and should be applied on a modified retrospective basis to existing debt instruments as of the beginning of the fiscal year for which the amendments are effective. Early adoption is permitted. As we previously assessed the embedded call (put) options associated with our Convertible Senior Notes in accordance with the requirements in this guidance, the adoption of this standard will have no impact on our consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This standard is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The guidance is effective for us beginning in the first quarter of 2019, and should be applied on a modified retrospective basis. Early adoption is permitted. We expect the adoption of this standard to have a material impact on our consolidated financial statements and related disclosures. In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. This standard eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Under this guidance, measurement-period adjustments will be recognized during the period in which they are determined. We adopted this standard in the current quarter and the adoption did not have a material impact on our consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). This standard provides a single model for revenue arising from contracts with customers and supersedes current revenue recognition guidance. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In July 2015, the FASB decided to defer the effective date by one year, and as a result, the guidance is effective for us beginning in the first quarter of 2018. Early adoption as of the original effective date would be permitted. The guidance permits companies to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net), and in April 2016, the FASB issued ASU No. 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing. These standards were issued to address implementation issues raised by the FASB-IASB Joint Transition Resource Group for Revenue Recognition (TRG). We are currently evaluating the impact the adoption of the new revenue guidance and related updates will have on our consolidated financial statements and related disclosures. In August 2014, the FASB issued ASU 2014-15, Disclosures of Uncertainties About an Entity’s Ability to Continue as a Going Concern. This standard provides guidance on how and when reporting entities must disclose going-concern uncertainties in their financial statements. The guidance is effective for us beginning in the first quarter of 2017. Early adoption is permitted. The adoption of this standard is not expected to have an impact on our consolidated financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Assets Measured at Fair Value on a Recurring Basis	The following table presents our assets and liabilities measured at fair value on a recurring basis using the above input categories (in thousands): As of March 31, 2016 As of December 31, 2015 Description Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents: Money market funds $ 21,330 $ — $ — $ 21,330 $ 210,533 $ — $ — $ 210,533 Total cash equivalents 21,330 — — 21,330 210,533 — — 210,533 Short-term investments: Certificates of deposit — 17,254 — 17,254 — 19,124 — 19,124 Corporate notes and bonds — 443,250 — 443,250 — 447,267 — 447,267 U.S. Government agencies — 285,523 — 285,523 — 301,384 — 301,384 Total short-term investments — 746,027 — 746,027 — 767,775 — 767,775 Total assets measured at fair value $ 21,330 $ 746,027 $ — $ 767,357 $ 210,533 $ 767,775 $ — $ 978,308 Liabilities Contingent earn-out $ — $ — $ 35,588 $ 35,588 $ — $ — $ — $ — Total liabilities measured at fair value $ — $ — $ 35,588 $ 35,588 $ — $ — $ — $ —

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Summary of Investments	Our investments consisted of the following (in thousands): As of March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term investment Certificates of deposit $ 17,240 $ 15 $ (1 ) $ 17,254 $ 17,254 Corporate notes and bonds 443,240 257 (247 ) 443,250 443,250 U.S. Government agencies 285,609 41 (127 ) 285,523 285,523 Total $ 746,089 $ 313 $ (375 ) $ 746,027 $ 746,027 As of December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Short-term investment Certificates of deposit $ 19,160 $ — $ (36 ) $ 19,124 $ 19,124 Corporate notes and bonds 448,688 — (1,421 ) 447,267 447,267 U.S. Government agencies 302,152 2 (770 ) 301,384 301,384 Total $ 770,000 $ 2 $ (2,227 ) $ 767,775 $ 767,775
Summary of Gross Unrealized Losses and Fair Value of Investments in a Continuous Unrealized Loss Position	The following tables present the gross unrealized losses and related fair values of our investments that have been in a continuous unrealized loss position (in thousands): As of March 31, 2016 Less Than 12 Months Greater Than 12 Months Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Certificates of deposit $ 1,159 $ (1 ) $ — $ — $ 1,159 $ (1 ) Corporate notes and bonds 256,480 (234 ) 15,974 (13 ) 272,454 (247 ) U.S. Government agencies 156,623 (125 ) 8,998 (2 ) 165,621 (127 ) Total $ 414,262 $ (360 ) $ 24,972 $ (15 ) $ 439,234 $ (375 ) As of December 31, 2015 Less Than 12 Months Greater Than 12 Months Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Certificates of deposit $ 18,404 $ (36 ) $ — $ — $ 18,404 $ (36 ) Corporate notes and bonds 430,466 (1,407 ) 16,801 (15 ) 447,267 (1,422 ) U.S. Government agencies 266,541 (761 ) 8,992 (8 ) 275,533 (769 ) Total $ 715,411 $ (2,204 ) $ 25,793 $ (23 ) $ 741,204 $ (2,227 )
Summary of Contractual Maturities of Investments	The following table summarizes the contractual maturities of our investments at March 31, 2016 (in thousands): Amortized Cost Fair Value Due within one year $ 371,071 $ 370,962 Due within one to two years 375,018 375,065 Total $ 746,089 $ 746,027

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment, net consisted of the following (in thousands): As of March 31, 2016 As of December 31, 2015 Computer equipment and software $ 132,862 $ 120,886 Leasehold improvements 43,901 41,626 Furniture and fixtures 14,314 13,470 Machinery and equipment 447 447 Total property and equipment 191,524 176,429 Less: accumulated depreciation (110,200 ) (98,061 ) Total property and equipment, net $ 81,324 $ 78,368

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2016
Business Acquisition [Line Items]
Schedule of Goodwill	Changes in the carrying amount of goodwill for the three months ended March 31, 2016 are as follows (in thousands): Amount Balance as of December 31, 2015 $ 750,288 Goodwill acquired 223,896 Balance as of March 31, 2016 $ 974,184
Schedule of Purchased Intangible Assets	Purchased intangible assets consisted of the following as of the dates below (in thousands): As of March 31, 2016 As of December 31, 2015 Developed technology $ 99,793 $ 78,193 Content 157,500 128,600 Customer relationships 108,700 75,300 Contract backlog 12,500 12,500 Trade names 15,500 12,400 Non-competition agreements 1,400 — Total intangible assets subject to amortization 395,393 306,993 Less: accumulated amortization (107,598 ) (92,433 ) Net intangible assets subject to amortization 287,795 214,560 In-process research and development 2,800 — Total net intangible assets $ 290,595 $ 214,560
Schedule of Expected Annual Amortization Expense of Intangible Assets	The expected annual amortization expense of intangible assets as of March 31, 2016 is presented below (in thousands): Years Ending December 31, Amount 2016 (remaining nine months) $ 47,401 2017 57,378 2018 45,694 2019 43,808 2020 30,186 2021 and thereafter 63,328 Total intangible assets subject to amortization 287,795 Total intangible assets with indefinite lives 2,800 Total $ 290,595
iSIGHT Security
Business Acquisition [Line Items]
Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block]	The estimated useful life and fair values of the identifiable intangible assets are as follows (in thousands): Preliminary Estimated Useful Life (in years) Amount Customer relationships 8 $ 32,600 Content 4 28,900 Developed technology 4-6 17,100 Trade name 5 3,100 Non-competition agreements 2 1,100 Total identifiable intangible assets $ 82,800
Schedule of Purchase Price Allocation	Allocation of the preliminary purchase price is as follows (in thousands): Amount Net tangible liabilities assumed $ (18,366 ) Intangible assets 82,800 Deferred tax liability (10,328 ) Goodwill 202,532 Total preliminary purchase price allocation $ 256,638
Invotas International Corporation
Business Acquisition [Line Items]
Schedule of Purchase Price Allocation	Allocation of the preliminary purchase price is as follows (in thousands): Amount Net tangible liabilities assumed $ (306 ) Intangible assets 8,400 Deferred tax liability (703 ) Goodwill 21,364 Total preliminary purchase price allocation $ 28,755
Schedule of Estimated Useful Life and Fair Values of the Identifiable Intangible Assets	The estimated useful life and fair values of the identifiable intangible assets are as follows (in thousands): Preliminary Estimated Useful Life (in years) Amount Developed technology 4 $ 4,500 In-process research and development N/A 2,800 Customer relationships 10 800 Non-competition agreements 3 300 Total identifiable intangible assets $ 8,400

Restructuring Charges (Tables)

Restructuring Charges (Tables)	3 Months Ended
	Mar. 31, 2016
Restructuring and Related Activities [Abstract]
Summary of Restructuring Activities	The following table sets forth a summary of restructuring activities during the three months ended March 31, 2016 (in thousands): Severance and related costs Facilities costs Total costs Balance, December 31, 2015 $ — $ 217 $ 217 Provision for restructuring charges 1,390 280 1,670 Cash payments (984 ) (344 ) (1,328 ) Other adjustments — 324 324 Balance, March 31, 2016 $ 406 $ 477 $ 883

Deferred Revenue (Tables)

Deferred Revenue (Tables)	3 Months Ended
	Mar. 31, 2016
Revenue Recognition [Abstract]
Schedule of Deferred Revenue	Deferred revenue consisted of the following as of the dates below (in thousands): As of March 31, 2016 As of December 31, 2015 Product, current $ 8,083 $ 8,200 Subscription and services, current 321,012 296,969 Total deferred revenue, current 329,095 305,169 Product, non-current 3,231 3,051 Subscription and services, non-current 233,756 218,778 Total deferred revenue, non-current 236,987 221,829 Total deferred revenue $ 566,082 $ 526,998

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Schedule of the Liability and Equity Components of the Convertible Senior Notes	he liability and equity components of the Convertible Senior Notes consisted of the following (in thousands): As of March 31, 2016 As of December 31, 2015 Series A Notes Series B Notes Series A Notes Series B Notes Liability component: Principal $ 460,000 $ 460,000 $ 460,000 $ 460,000 Less: Convertible senior notes discounts and issuance costs, net of amortization (88,726 ) (116,296 ) (93,469 ) (120,333 ) Net carrying amount $ 371,274 $ 343,704 $ 366,531 $ 339,667 Equity component, net of issuance costs $ 92,567 $ 117,834 $ 92,567 $ 117,834
Schedule of Interest Expense related to the Convertible Senior Notes	Interest expense related to the Convertible Senior Notes consisted of the following (in thousands): Three Months Ended March 31, 2016 Series A Notes Series B Notes Coupon interest $ 1,150 $ 1,869 Amortization of convertible senior notes discounts and issuance costs 4,743 4,037 Total interest expense recognized $ 5,893 $ 5,906 Effective interest rate on the liability component 6.4 % 7.0 %

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Non-cancelable Minimum Rental Payments for Operating Leases	The aggregate future non-cancelable minimum rental payments on our operating leases, as of March 31, 2016 , are as follows (in thousands): Years Ending December 31, Amount 2016 (remaining nine months) $ 11,509 2017 13,754 2018 8,137 2019 5,616 2020 5,167 2021 and thereafter 7,092 Total $ 51,275

Common Shares Reserved for Is31

Common Shares Reserved for Issuance (Tables)	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Issuance	We had reserved shares of common stock for issuance as follows (in thousands): As of March 31, 2016 As of December 31, 2015 Reserved under stock award plans 44,443 38,500 Convertible Senior Notes 15,141 15,141 ESPP 4,830 3,214 Total 64,414 56,855

Equity Award Plans (Tables)

Equity Award Plans (Tables)	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of the Activity for Stock Option Changes and Summary of Information Related to Options Vested and Expected to Vest and Options Exercisable	A summary of the activity for our stock option changes during the reporting period and a summary of information related to options vested and options exercisable are presented below (in thousands, except per share amounts and contractual life years): Options Outstanding Number of Shares Weighted- Average Exercise Price Weighted- Average Grant Date Fair Value (per share) Weighted- Aggregate Intrinsic Value Balance — December 31, 2015 11,494 $ 10.67 6.9 $ 149,157 Granted — — $ — Exercised (601 ) 4.73 7,063 Cancelled (266 ) 16.99 Balance — March 31, 2016 10,627 $ 10.84 6.5 $ 110,382 Options exercisable — March 31, 2016 7,466 $ 9.28 6.2 $ 84,211
Summary of Activity for Restricted Common Stock, RSAs and RSUs and Summary of Information Related to Unvested Restricted Common Stock, RSAs and RSUs and those Expected to Vest	A summary of the activity for our restricted common stock, RSAs and RSUs during the reporting period and a summary of information related to unvested restricted common stock, RSAs and RSUs and those expected to vest based on the achievement of a performance condition are presented below (in thousands, except per share amounts and contractual life years): Number of Weighted- Weighted- Aggregate Unvested balance — December 31, 2015 20,054 $ 33.68 1.6 $ 415,912 Granted 6,496 12.56 Vested (1,475 ) 40.45 Cancelled (1,179 ) 34.29 Unvested balance — March 31, 2016 23,896 $ 26.82 1.6 $ 429,886 Unvested awards for which the requisite service period has not been rendered but that are expected to vest based on the achievement of a performance condition — March 31, 2016 7,030 $ 21.49 1.6 $ 126,465
Schedule of Stock-Based Compensation Expense Related to Stock Options, ESPP and Restricted Stock Units and Awards	Stock-based compensation expense related to stock options, ESPP and restricted stock units and awards is included in the condensed consolidated statements of operations as follows (in thousands): Three Months Ended March 31, 2016 2015 Cost of product revenue $ 667 $ 268 Cost of subscription and services revenue 9,601 6,378 Research and development 24,430 16,035 Sales and marketing 16,154 16,454 General and administrative 13,215 10,740 Total $ 64,067 $ 49,875

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Schedule of Computation of Net Loss per Common Share	The following table sets forth the computation of net loss per common share (in thousands, except per share amounts): Three Months Ended March 31, 2016 2015 Numerator: Net loss $ (155,900 ) $ (133,964 ) Denominator: Weighted average number of shares outstanding—basic and diluted 158,781 151,651 Net loss per share—basic and diluted $ (0.98 ) $ (0.88 )
Schedule of Outstanding Options and Unvested Shares Excluded from Computation of Diluted Net Loss per Share	The following outstanding options and unvested shares were excluded (as common stock equivalents) from the computation of diluted net loss per common share for the periods presented as their effect would have been anti-dilutive (in thousands): As of March 31, 2016 2015 Options to purchase common stock 10,627 15,403 Unvested early exercised common shares 647 1,959 Unvested restricted stock awards and units 23,896 9,936 Convertible senior notes 15,141 — ESPP shares 667 312

Segment and Major Customers I34

Segment and Major Customers Information (Tables)	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Schedule of Revenue by Geographic Region	Revenue by geographic region based on the billing address is as follows (in thousands): Three Months Ended March 31, 2016 2015 Revenue: United States $ 115,852 $ 89,189 EMEA 24,442 16,792 APAC 21,823 13,721 Other 5,849 5,668 Total revenue $ 167,966 $ 125,370
Summary of Long lived Assets by Geographic Region Based on Physical Location	Long lived assets by geographic region based on physical location is as follows (in thousands): As of March 31, 2016 As of December 31, 2015 Property and Equipment, net: United States $ 58,099 $ 57,537 International 23,225 20,831 Total property and equipment, net $ 81,324 $ 78,368

Description of Business and S35

Description of Business and Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	Feb. 01, 2016	Jan. 14, 2016	Jun. 30, 2015	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Liabilities incurred				$ 35,588,000	$ 0
Consideration transferred, equity interests				39,300,000	$ 0
Debt Instrument [Line Items]
Stock repurchased during period			$ 150,000,000
Stock repurchase during period (shares)			3,300,000
New Accounting Pronouncement, Early Adoption [Line Items]
Income tax deficiencies, less than				$ 100,000
Convertible Senior Notes
Debt Instrument [Line Items]
Net proceeds from issuance of convertible senior notes			$ 896,500,000
Invotas International Corporation
Business Acquisition [Line Items]
Purchase consideration, cash paid	$ 17,700,000
iSIGHT Security
Business Acquisition [Line Items]
Purchase consideration, cash paid		$ 192,800,000
Liabilities incurred		$ 35,600,000
Common Stock | Invotas International Corporation
Business Acquisition [Line Items]
Equity interest issuable, number of shares	742,026
Consideration transferred, equity interests	$ 11,100,000
Common Stock | iSIGHT Security
Business Acquisition [Line Items]
Equity interest issuable, number of shares		1,793,305
Consideration transferred, equity interests		$ 28,200,000
Series A Notes | Convertible Senior Notes
Debt Instrument [Line Items]
Principal amount			$ 460,000,000
Interest rate			1.00%
Series B Notes | Convertible Senior Notes
Debt Instrument [Line Items]
Principal amount			$ 460,000,000
Interest rate			1.625%
Accounting Standards Update 2016-09 | New Accounting Pronouncement, Early Adoption, Effect | Retained Earnings
New Accounting Pronouncement, Early Adoption [Line Items]
Cumulative-effect adjustment to retained earnings						$ 3,400,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	$ 21,330	$ 210,533
Total short-term investments	746,027	767,775
Total assets measured at fair value	767,357	978,308
Contingent earn-out	35,588	0
Total liabilities measured at fair value	35,588	0
Certificates of deposit | Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	17,254	19,124
Corporate notes and bonds | Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	443,250	447,267
U.S. Government agencies | Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	285,523	301,384
Money market funds | Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	21,330	210,533
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	21,330	210,533
Total short-term investments	0	0
Total assets measured at fair value	21,330	210,533
Contingent earn-out	0	0
Total liabilities measured at fair value	0	0
Level 1 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 1 | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 1 | U.S. Government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	21,330	210,533
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0	0
Total short-term investments	746,027	767,775
Total assets measured at fair value	746,027	767,775
Contingent earn-out	0	0
Total liabilities measured at fair value	0	0
Level 2 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	17,254	19,124
Level 2 | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	443,250	447,267
Level 2 | U.S. Government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	285,523	301,384
Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0	0
Total short-term investments	0	0
Total assets measured at fair value	0	0
Contingent earn-out	35,588	0
Total liabilities measured at fair value	35,588	0
Level 3 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 3 | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 3 | U.S. Government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	$ 0	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Level 3 | iSIGHT Security
Debt Instrument [Line Items]
Earn-out period of performance	2 years 6 months
Level 3 | Minimum | iSIGHT Security
Debt Instrument [Line Items]
Quarterly revenue growth	30.00%
Discount rate	6.30%
Level 3 | Maximum | iSIGHT Security
Debt Instrument [Line Items]
Quarterly revenue growth	120.00%
Discount rate	7.10%
Level 3 | Weighted Average | iSIGHT Security
Debt Instrument [Line Items]
Expected volatility	16.50%
Fair Value Assumptions, Comparable Company Revenue Growth Correlated To Market	44.70%
Level 2 | Convertible Senior Notes
Debt Instrument [Line Items]
Fair value of debt	$ 762.9

Investments - Summary of Invest

Investments - Summary of Investments (Details) - Short-term investments - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 746,089	$ 770,000
Gross Unrealized Gains	313	2
Gross Unrealized Losses	(375)	(2,227)
Estimated Fair Value	746,027	767,775
Short-term investment	746,027	767,775
Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,240	19,160
Gross Unrealized Gains	15	0
Gross Unrealized Losses	(1)	(36)
Estimated Fair Value	17,254	19,124
Short-term investment	17,254	19,124
Corporate notes and bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	443,240	448,688
Gross Unrealized Gains	257	0
Gross Unrealized Losses	(247)	(1,421)
Estimated Fair Value	443,250	447,267
Short-term investment	443,250	447,267
U.S. Government agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	285,609	302,152
Gross Unrealized Gains	41	2
Gross Unrealized Losses	(127)	(770)
Estimated Fair Value	285,523	301,384
Short-term investment	$ 285,523	$ 301,384

Investments - Summary of Gross

Investments - Summary of Gross Unrealized Losses and Fair Value of Investments in a Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	$ 414,262	$ 715,411
Unrealized Loss, Less Than 12 Months	(360)	(2,204)
Fair Value, Greater Than 12 Months	24,972	25,793
Unrealized Loss, Greater Than 12 Months	(15)	(23)
Fair Value	439,234	741,204
Unrealized Loss	(375)	(2,227)
Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	1,159	18,404
Unrealized Loss, Less Than 12 Months	(1)	(36)
Fair Value, Greater Than 12 Months	0	0
Unrealized Loss, Greater Than 12 Months	0	0
Fair Value	1,159	18,404
Unrealized Loss	(1)	(36)
Corporate notes and bonds
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	256,480	430,466
Unrealized Loss, Less Than 12 Months	(234)	(1,407)
Fair Value, Greater Than 12 Months	15,974	16,801
Unrealized Loss, Greater Than 12 Months	(13)	(15)
Fair Value	272,454	447,267
Unrealized Loss	(247)	(1,422)
U.S. Government agencies
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	156,623	266,541
Unrealized Loss, Less Than 12 Months	(125)	(761)
Fair Value, Greater Than 12 Months	8,998	8,992
Unrealized Loss, Greater Than 12 Months	(2)	(8)
Fair Value	165,621	275,533
Unrealized Loss	$ (127)	$ (769)

Investments - Narrative (Detail

Investments - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Other than temporary impairment	$ 0	$ 0
Ownership percentage		12.50%
Investment, carrying value	$ 1,600,000	$ 1,800,000

Investments - Summary of Contra

Investments - Summary of Contractual Maturities of Investments (Details) $ in Thousands	Mar. 31, 2016USD ($)
Investments, Debt and Equity Securities [Abstract]
Due within one year, amortized cost	$ 371,071
Due within one to two years, amortized cost	375,018
Amortized Cost	746,089
Due within one year, fair value	370,962
Due within one to two years, fair value	375,065
Fair Value	$ 746,027

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 191,524	$ 176,429
Less: accumulated depreciation	(110,200)	(98,061)
Total property and equipment, net	81,324	78,368
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	132,862	120,886
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	43,901	41,626
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	14,314	13,470
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 447	$ 447

Property and Equipment - Narrat

Property and Equipment - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 14.1	$ 14.3

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($)	Feb. 01, 2016	Jan. 14, 2016	Mar. 31, 2016	Mar. 31, 2015
Business Acquisition [Line Items]
Contingent earn-out in connection with acquisitions			$ 35,588,000	$ 0
Consideration transferred, equity interests			$ 39,300,000	0
Granted (shares)			6,496,000
Amortization of intangible assets			$ 15,200,000	$ 11,800,000
iSIGHT Security
Business Acquisition [Line Items]
Purchase consideration, cash paid		$ 192,800,000
Contingent earn-out in connection with acquisitions		35,600,000
Total purchase consideration		256,600,000
Contingent earn-out			41,300,000
Acquisition costs		7,000,000
Goodwill deductible for U.S. federal income tax purposes		$ 0
Business acquisition, pro forma revenue			9,400,000
Business combination, pro forma net loss			$ 2,300,000
iSIGHT Security | Customer relationships
Business Acquisition [Line Items]
Discount rate		15.00%
iSIGHT Security | Content
Business Acquisition [Line Items]
Discount rate		14.00%
iSIGHT Security | Developed technology
Business Acquisition [Line Items]
Discount rate		14.00%
Royalty percentage		10.00%
iSIGHT Security | Trade name
Business Acquisition [Line Items]
Discount rate		15.00%
Royalty percentage		1.00%
iSIGHT Security | General and administrative
Business Acquisition [Line Items]
Acquisition related costs		$ 1,900,000
iSIGHT Security | Common Stock
Business Acquisition [Line Items]
Equity interest issuable, number of shares		1,793,305
Consideration transferred, equity interests		$ 28,200,000
Invotas International Corporation
Business Acquisition [Line Items]
Purchase consideration, cash paid	$ 17,700,000
Requisite service period	4 years
Performance milestone determination period	3 years
Total purchase consideration	$ 29,000,000
Acquisition costs	700,000
Goodwill deductible for U.S. federal income tax purposes	$ 0
Invotas International Corporation | In-process research and development
Business Acquisition [Line Items]
Discount rate	17.00%
Invotas International Corporation | Developed technology
Business Acquisition [Line Items]
Discount rate	16.00%
Invotas International Corporation | Restricted Stock Units (RSUs)
Business Acquisition [Line Items]
Granted (shares)	1,002,748
Invotas International Corporation | General and administrative
Business Acquisition [Line Items]
Acquisition related costs	$ 500,000
Invotas International Corporation | Common Stock
Business Acquisition [Line Items]
Equity interest issuable, number of shares	742,026
Consideration transferred, equity interests	$ 11,100,000
Invotas International Corporation | Unvested Restricted Stock Awards And Restricted Stock Units
Business Acquisition [Line Items]
Granted (shares)	95,614

Business Combinations - Schedul

Business Combinations - Schedule of Purchase Price Allocation (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Feb. 01, 2016	Jan. 14, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 974,184			$ 750,288
Invotas International Corporation
Business Acquisition [Line Items]
Net tangible liabilities assumed		$ (306)
Intangible assets		8,400
Deferred tax liability		(703)
Goodwill		21,364
Total preliminary purchase price allocation		$ 28,755
iSIGHT Security
Business Acquisition [Line Items]
Net tangible liabilities assumed			$ (18,366)
Intangible assets			82,800
Deferred tax liability			(10,328)
Goodwill			202,532
Total preliminary purchase price allocation			$ 256,638

Business Combinations - Sched46

Business Combinations - Schedule of Estimated Useful Life and Fair Values of the Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Feb. 01, 2016	Jan. 14, 2016
Invotas International Corporation
Business Acquisition [Line Items]
Intangible assets	$ 8,400
iSIGHT Security
Business Acquisition [Line Items]
Intangible assets		$ 82,800
In-process research and development | Invotas International Corporation
Business Acquisition [Line Items]
Intangible assets	$ 2,800
Customer relationships | Invotas International Corporation
Business Acquisition [Line Items]
Finite lived acquired assets, useful life	10 years
Intangible assets	$ 800
Customer relationships | iSIGHT Security
Business Acquisition [Line Items]
Finite lived acquired assets, useful life		8 years
Intangible assets		$ 32,600
Content | iSIGHT Security
Business Acquisition [Line Items]
Finite lived acquired assets, useful life		4 years
Intangible assets		$ 28,900
Developed technology | Invotas International Corporation
Business Acquisition [Line Items]
Finite lived acquired assets, useful life	4 years
Intangible assets	$ 4,500
Developed technology | iSIGHT Security
Business Acquisition [Line Items]
Intangible assets		$ 17,100
Developed technology | iSIGHT Security | Minimum
Business Acquisition [Line Items]
Finite lived acquired assets, useful life		4 years
Developed technology | iSIGHT Security | Maximum
Business Acquisition [Line Items]
Finite lived acquired assets, useful life		6 years
Trade name | iSIGHT Security
Business Acquisition [Line Items]
Finite lived acquired assets, useful life		5 years
Intangible assets		$ 3,100
Non-competition agreements | Invotas International Corporation
Business Acquisition [Line Items]
Finite lived acquired assets, useful life	3 years
Intangible assets	$ 300
Non-competition agreements | iSIGHT Security
Business Acquisition [Line Items]
Finite lived acquired assets, useful life		2 years
Intangible assets		$ 1,100

Business Combinations - Sched47

Business Combinations - Schedule of Purchased Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Goodwill, beginning	$ 750,288
Goodwill acquired	223,896
Goodwill, ending	974,184
Total intangible assets subject to amortization	395,393	$ 306,993
Less: accumulated amortization	(107,598)	(92,433)
Total intangible assets subject to amortization	287,795	214,560
Total intangible assets with indefinite lives	2,800
Total net intangible assets	290,595	214,560
In-process research and development
Goodwill [Roll Forward]
Total intangible assets with indefinite lives	2,800	0
Developed technology
Goodwill [Roll Forward]
Total intangible assets subject to amortization	99,793	78,193
Content
Goodwill [Roll Forward]
Total intangible assets subject to amortization	157,500	128,600
Customer relationships
Goodwill [Roll Forward]
Total intangible assets subject to amortization	108,700	75,300
Contract backlog
Goodwill [Roll Forward]
Total intangible assets subject to amortization	12,500	12,500
Trade names
Goodwill [Roll Forward]
Total intangible assets subject to amortization	15,500	12,400
Non-competition agreements
Goodwill [Roll Forward]
Total intangible assets subject to amortization	$ 1,400	$ 0

Business Combinations - Sched48

Business Combinations - Schedule of Expected Annual Amortization Expense of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
2016 (remaining nine months)	$ 47,401
2,017	57,378
2,018	45,694
2,019	43,808
2,020	30,186
2021 and thereafter	63,328
Total intangible assets subject to amortization	287,795	$ 214,560
Total intangible assets with indefinite lives	2,800
Total net intangible assets	$ 290,595	$ 214,560

Restructuring Charges - Summary

Restructuring Charges - Summary of Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Restructuring Reserve [Roll Forward]
Balance, December 31, 2015	$ 217
Provision for restructuring charges	1,670	$ 0
Cash payments	(1,328)
Other adjustments	324
Balance, March 31, 2016	883
Severance and related costs
Restructuring Reserve [Roll Forward]
Balance, December 31, 2015	0
Provision for restructuring charges	1,390
Cash payments	(984)
Other adjustments	0
Balance, March 31, 2016	406
Facilities costs
Restructuring Reserve [Roll Forward]
Balance, December 31, 2015	217
Provision for restructuring charges	280
Cash payments	(344)
Other adjustments	324
Balance, March 31, 2016	$ 477

Restructuring Charges - Narrati

Restructuring Charges - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 883	$ 217
Severance and related costs
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	406	0
Facilities costs
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 477	$ 217

Deferred Revenue - Schedule of

Deferred Revenue - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	$ 329,095	$ 305,169
Total deferred revenue, non-current	236,987	221,829
Total deferred revenue	566,082	526,998
Deferred revenue in connection with acquisitions	21,100
Product
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	8,083	8,200
Total deferred revenue, non-current	3,231	3,051
Subscription and services
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	321,012	296,969
Total deferred revenue, non-current	$ 233,756	$ 218,778

Convertible Senior Notes - Narr

Convertible Senior Notes - Narrative - Convertible Senior Notes (Details) - Convertible Senior Notes	1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2015USD ($)day$ / shares	Mar. 31, 2016	Jun. 30, 2015USD ($)$ / shares
Debt Instrument [Line Items]
Initial purchaser's discount	$ 23,000,000		$ 23,000,000
Debt issuance costs	500,000		$ 500,000
Net proceeds from issuance of convertible senior notes	$ 896,500,000
Conversion price | $ / shares	$ 60.76		$ 60.76
Threshold note trading days | day	5
Threshold consecutive note trading days	5 days
Threshold percentage of note price trigger	98.00%
Redemption price, percentage	100.00%
Redemption price triggered by fundamental change, percentage	100.00%
Remaining discount and issuance cost, weighted average amortization period		5 years
Conversion ratio			0.0164572
Subsequent to September 30, 2015
Debt Instrument [Line Items]
Threshold trading days | day	20
Threshold consecutive trading days	30 days
Threshold percentage of stock price trigger	130.00%
Series A Notes
Debt Instrument [Line Items]
Principal amount	$ 460,000,000		$ 460,000,000
Interest rate	1.00%		1.00%
Series B Notes
Debt Instrument [Line Items]
Principal amount	$ 460,000,000		$ 460,000,000
Interest rate	1.625%		1.625%
Series B Notes | On or after June 1, 2020 until June 1, 2022
Debt Instrument [Line Items]
Threshold trading days | day	20
Threshold consecutive trading days	30 days
Threshold percentage of stock price trigger	130.00%
Series B Notes | On or after June 1, 2020 until June 1, 2022 | Maximum
Debt Instrument [Line Items]
Required trading days since notice of redemption	3 days
Debt, Liability Component
Debt Instrument [Line Items]
Initial purchaser's discount	$ 17,600,000		$ 17,600,000
Debt issuance costs	400,000		400,000
Debt, Equity Component
Debt Instrument [Line Items]
Initial purchaser's discount	5,400,000		5,400,000
Debt issuance costs	$ 100,000		$ 100,000

Convertible Senior Notes - Sche

Convertible Senior Notes - Schedule of the Liability and Equity Components of the Convertible Senior Notes (Details) - Convertible Senior Notes - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Series A Notes
Debt Instrument [Line Items]
Principal	$ 460,000	$ 460,000
Less: Convertible senior notes discounts and issuance costs, net of amortization	(88,726)	(93,469)
Net carrying amount	371,274	366,531
Equity component, net of issuance costs	92,567	92,567
Series B Notes
Debt Instrument [Line Items]
Principal	460,000	460,000
Less: Convertible senior notes discounts and issuance costs, net of amortization	(116,296)	(120,333)
Net carrying amount	343,704	339,667
Equity component, net of issuance costs	$ 117,834	$ 117,834

Convertible Senior Notes - Sc54

Convertible Senior Notes - Schedule of Interest Expense related to the Convertible Senior Notes (Details) - Convertible Senior Notes $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)
Series A Notes
Debt Instrument [Line Items]
Coupon interest	$ 1,150
Amortization of convertible senior notes discounts and issuance costs	4,743
Total interest expense recognized	$ 5,893
Effective interest rate on the liability component	6.40%
Series B Notes
Debt Instrument [Line Items]
Coupon interest	$ 1,869
Amortization of convertible senior notes discounts and issuance costs	4,037
Total interest expense recognized	$ 5,906
Effective interest rate on the liability component	7.00%

Convertible Senior Notes - Na55

Convertible Senior Notes - Narrative - Prepaid Forward Stock Purchase (Details) shares in Millions, $ in Millions	1 Months Ended
	Jun. 30, 2015USD ($)shares
Debt Disclosure [Abstract]
Stock repurchased during period | $	$ 150
Stock repurchase during period (shares) | shares	3.3

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details)	3 Months Ended
	Mar. 31, 2016USD ($)claim	Mar. 31, 2015USD ($)	Dec. 31, 2015USD ($)
Long-term Purchase Commitment [Line Items]
Rent expense	$ 3,600,000	$ 3,200,000
Future minimum sublease rentals	1,000,000
Letters of credit available	1,200,000		$ 1,200,000
Amount drawn against letters of credit	0
Non-cancellable open orders	$ 14,200,000		$ 16,900,000
Number of claims | claim	0
Software and Services
Long-term Purchase Commitment [Line Items]
Non-cancellable open orders	$ 30,800,000

Commitments and Contingencies57

Commitments and Contingencies - Schedule of Future Non-cancelable Minimum Rental Payments for Operating Leases (Details) $ in Thousands	Mar. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
2016 (remaining nine months)	$ 11,509
2,017	13,754
2,018	8,137
2,019	5,616
2,020	5,167
2021 and thereafter	7,092
Total	$ 51,275

Common Shares Reserved for Is58

Common Shares Reserved for Issuance - Narrative (Details)	3 Months Ended
	Mar. 31, 2016vote_per_share$ / sharesshares	Dec. 31, 2015$ / sharesshares
Class of Stock [Line Items]
Common stock, shares authorized (shares)	1,000,000,000	1,000,000,000
Common stock, par value (usd per share) | $ / shares	$ 0.0001	$ 0.0001
Voting right per common share | vote_per_share	1
Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock authorized (shares)	100,000,000	100,000,000
Preferred stock, par value (usd per share) | $ / shares	$ 0.0001	$ 0.0001
Preferred stock, shares issued (shares)	0	0
Preferred stock outstanding (shares)	0	0

Common Shares Reserved for Is59

Common Shares Reserved for Issuance - Schedule of Reserved Shares of Common Stock for Issuance (Details) - shares shares in Thousands	Mar. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Shares reserved for future issuance (shares)	64,414	56,855
ESPP
Class of Stock [Line Items]
Shares reserved for future issuance (shares)	4,830	3,214
Convertible Senior Notes
Class of Stock [Line Items]
Shares reserved for future issuance (shares)	15,141	15,141
Reserved under stock award plans
Class of Stock [Line Items]
Shares reserved for future issuance (shares)	44,443	38,500

Equity Award Plans - Narrative

Equity Award Plans - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance (shares)	64,414,000	56,855,000
Granted (shares)	6,496,000
Compensation cost not yet recognized	$ 527.7
Compensation cost not yet recognized, period for recognition	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Acquisitions	3,600,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Acquisition price at lower of fair market value, percentage	85.00%
Shares reserved for future issuance (shares)	4,830,720	3,214,287
2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
General vesting period	4 years
Award expiration period from grant date	10 years
Employee stock ownership, combined voting power of all stock	10.00%
Minimum exercise price as a percentage of the fair value per share	110.00%
Award expiration period, for excess voting power grants	5 years
Shares reserved for future issuance (shares)	10,100,000	7,200,000
2013 Plan | Employee stock option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value, percentage	100.00%

Equity Award Plans - Summary of

Equity Award Plans - Summary of the Activity for Stock Option Changes and Summary of Information Related to Options Vested and Expected to Vest and Options Exercisable (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options outstanding (shares)	11,494
Granted (shares)	0
Exercised (shares)	(601)
Cancelled (shares)	(266)
Ending balance, options outstanding (shares)	10,627	11,494
Options exercisable (shares)	7,466
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning balance, weighted average exercise price (usd per share)	$ 10.67
Granted, weighted average exercise price (usd per share)	0
Exercised, weighted average exercise price (usd per share)	4.73
Cancelled, weighted average exercise price (usd per share)	16.99
Ending balance, weighted average exercise price (usd per share)	10.84	$ 10.67
Options exercisable, weighted average exercise price (usd per share)	9.28
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options weighted-average grant date fair value per share (usd per share)	$ 0
Beginning balance, options outstanding, weighted average contractual life	6 years 6 months	6 years 10 months 24 days
Ending balance, options outstanding, weighted average contractual life	6 years 6 months	6 years 10 months 24 days
Options exercisable, weighted average contractual life	6 years 2 months 12 days
Beginning balance, options outstanding, aggregate intrinsic value	$ 149,157
Exercised, aggregate intrinsic value	7,063
Ending balance, options outstanding, aggregate intrinsic value	110,382	$ 149,157
Options exercisable, aggregate intrinsic value	$ 84,211

Equity Award Plans - Summary 62

Equity Award Plans - Summary of Activity for Restricted Common Stock, RSAs and RSUs and Summary of Information Related to Unvested Restricted Common Stock, RSAs and RSUs and those Expected to Vest (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Beginning balance, unvested (shares)	20,054
Granted (shares)	6,496
Vested (shares)	(1,475)
Cancelled (shares)	(1,179)
Ending balance, unvested (shares)	23,896	20,054
Expected to vest (shares)	7,030
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance, unvested, weighted average grant date fair value (per share)	$ 33.68
Weighted average grant date fair value, granted (per share)	12.56
Weighted average grant date fair value, vested (per share)	40.45
Weighted average grant date fair value, cancelled (per share)	34.29
Ending balance, unvested, weighted average grant date fair value (per share)	26.82	$ 33.68
Weighted average grant date fair value, expected to vest (per share)	$ 21.49
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Beginning balance, weighted-average remaining contractual term	1 year 7 months 6 days	1 year 7 months 6 days
Ending balance, weighted-average remaining contractual term	1 year 7 months 6 days	1 year 7 months 6 days
Expected to vest, weighted-average remaining contractual term	1 year 7 months 6 days
Beginning balance, aggregate intrinsic value	$ 415,912
Ending balance, aggregate intrinsic value	429,886	$ 415,912
Expected to vest, aggregate intrinsic value	$ 126,465

Equity Award Plans - Schedule o

Equity Award Plans - Schedule of Stock-Based Compensation Expense Related to Stock Options, ESPP and Restricted Stock Units and Awards (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 64,067	$ 49,875
Cost of product revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	667	268
Cost of subscription and services revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	9,601	6,378
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	24,430	16,035
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	16,154	16,454
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 13,215	$ 10,740

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Provision for (benefit from) income taxes	$ (10,030)	$ 977

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Computation of Net Loss per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Numerator:
Net loss	$ (155,900)	$ (133,964)
Denominator:
Weighted average number of shares outstanding—basic and diluted (shares)	158,781	151,651
Net loss per share—basic and diluted (usd per share)	$ (0.98)	$ (0.88)

Net Loss per Share - Schedule66

Net Loss per Share - Schedule of Outstanding Options and Unvested Shares Excluded from Computation of Diluted Net Loss per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	10,627	15,403
Unvested early exercised common shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	647	1,959
Unvested restricted stock awards and units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	23,896	9,936
Convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	15,141	0
ESPP shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	667	312

Employee Benefit Plan - Narrati

Employee Benefit Plan - Narrative (Details)	3 Months Ended
	Mar. 31, 2016USD ($)
Compensation and Retirement Disclosure [Abstract]
Employer contributions vested percentage	100.00%
Employer contributions to 401(k)	$ 0

Segment and Major Customers I68

Segment and Major Customers Information - Schedule of Revenue by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 167,966	$ 125,370
Reportable Geographical Components | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	115,852	89,189
Reportable Geographical Components | EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	24,442	16,792
Reportable Geographical Components | APAC
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	21,823	13,721
Reportable Geographical Components | Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 5,849	$ 5,668

Segment and Major Customers I69

Segment and Major Customers Information - Summary of Long lived Assets by Geographic Region Based on Physical Location (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Entity Location [Line Items]
Total property and equipment, net	$ 81,324	$ 78,368
Reportable Geographical Components | United States
Entity Location [Line Items]
Total property and equipment, net	58,099	57,537
Reportable Geographical Components | International
Entity Location [Line Items]
Total property and equipment, net	$ 23,225	$ 20,831

Segment and Major Customers I70

Segment and Major Customers Information - Narrative (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2016reporting_segmentcustomer	Mar. 31, 2015customer	Dec. 31, 2015customer
Revenue, Major Customer [Line Items]
Number of reportable segment and operating unit structure | reporting_segment	1
Customer concentration risk | Sales revenue, net | Distributor One
Revenue, Major Customer [Line Items]
Number of major customers	1	1
Concentration risk percentage	17.00%	13.00%
Customer concentration risk | Sales revenue, net | Reseller
Revenue, Major Customer [Line Items]
Number of major customers	1	1
Concentration risk percentage	11.00%	11.00%
Customer concentration risk | Accounts Receivable
Revenue, Major Customer [Line Items]
Number of major customers	0		2
Customer concentration risk | Accounts Receivable | Distributor One
Revenue, Major Customer [Line Items]
Concentration risk percentage			20.00%
Customer concentration risk | Accounts Receivable | Distributor Two
Revenue, Major Customer [Line Items]
Concentration risk percentage			12.00%