Mandiant (MNDT) 10-Q 8 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	FIREEYE, INC.
Entity Central Index Key	1370880
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		156,330,017

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$136,776	$146,363
Short-term investments	260,838	255,845
Accounts receivable, net of allowance for doubtful accounts of $1,390 and $586 at March 31, 2015 and December 31, 2014, respectively	160,095	193,182
Inventories	10,505	7,952
Deferred tax assets, current portion	21,968	25,126
Prepaid expenses and other current assets	27,457	28,669
Total current assets	617,639	657,137
Property and equipment, net	81,030	82,298
Goodwill	750,288	750,288
Intangible assets, net	249,858	261,625
Deposits and other long-term assets	7,186	7,533
TOTAL ASSETS	1,706,001	1,758,881
CURRENT LIABILITIES:
Accounts payable	28,505	34,057
Accrued and other current liabilities	26,060	24,596
Accrued compensation	61,876	64,551
Deferred revenue, current portion	217,211	203,877
Total current liabilities	333,652	327,081
Deferred revenue, non-current portion	161,553	148,666
Deferred tax liabilities, non-current portion	21,780	24,903
Other long-term liabilities	9,400	7,403
Total liabilities	526,385	508,053
Commitments and contingencies (NOTE 8)
Stockholders' equity:
Common stock, par value of $0.0001 per share; 1,000,000 shares authorized, 156,139 shares and 152,860 shares issued and outstanding as of March 31, 2015 and December 31, 2014, respectively	16	15
Additional paid-in capital	1,980,894	1,918,546
Accumulated other comprehensive loss	-38	-441
Accumulated deficit	-801,256	-667,292
Total stockholders’ equity	1,179,616	1,250,828
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$1,706,001	$1,758,881

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$1,390	$586
Common stock, par value (usd per share)	$0.00	$0.00
Common stock, shares authorized (shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (shares)	156,139,000	152,860,000
Common stock, shares outstanding (shares)	156,139,000	152,860,000

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenue:
Product	$40,237	$24,252
Subscription and services	85,133	49,728
Total revenue	125,370	73,980
Cost of revenue:
Product	15,200	10,326
Subscription and services	36,851	24,967
Total cost of revenue	52,051	35,293
Total gross profit	73,319	38,687
Operating expenses:
Research and development	65,605	41,970
Sales and marketing	107,595	76,854
General and administrative	32,607	27,100
Total operating expenses	205,807	145,924
Operating loss	-132,488	-107,237
Interest income	269	45
Interest expense	0	-7
Other expense, net	-768	-54
Loss before income taxes	-132,987	-107,253
Provision for (benefit from) income taxes	977	-6,042
Net loss attributable to common stockholders	($133,964)	($101,211)
Net loss per share attributable to common stockholders, basic and diluted (usd per share)	($0.88)	($0.76)
Weighted average shares used in computing net loss per share attributable to common stockholders, basic and diluted (shares)	151,651	133,976

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net loss	($133,964)	($101,211)
Change in net unrealized loss on available-for-sale investments, net of tax	403	-138
Comprehensive loss	($133,561)	($101,349)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	($133,964)	($101,211)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	26,581	20,706
Stock-based compensation	49,875	25,194
Deferred income taxes	82	-7,518
Other	509	89
Changes in operating assets and liabilities, net of acquisition of business:
Accounts receivable	32,736	15,221
Inventories	-2,554	1,405
Prepaid expenses and other assets	127	-2,509
Accounts payable	-4,219	-12,396
Accrued liabilities	2,068	6,016
Accrued compensation	-2,675	5,703
Deferred revenue	26,221	25,207
Other long-term liabilities	1,997	1,505
Net cash used in operating activities	-3,216	-22,588
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment and demonstration units	-12,669	-14,187
Purchases of short-term investments	-39,857	-143,522
Proceeds from maturities of short-term investments	34,655	0
Lease deposits	-370	-360
Net cash used in investing activities	-18,241	-158,069
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of stock	0	445,934
Proceeds from exercise of equity awards	11,870	2,075
Net cash provided by financing activities	11,870	448,009
Net change in cash and cash equivalents	-9,587	267,352
Cash and cash equivalents, beginning of period	146,363	173,918
Cash and cash equivalents, end of period	136,776	441,270
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for income taxes	536	781
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid follow-on public offering costs	0	1,639
Purchases of property and equipment and demonstration units in accounts payable and accrued liabilities	$5,382	$7,980

Description_of_Business_and_Su

Description of Business and Summary of Significant Accounting Policies (Notes)	3 Months Ended
	Mar. 31, 2015
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.
	On December 30, 2013, we acquired privately held Mandiant Corporation (“Mandiant”), a leading provider of advanced endpoint security products and security incident response management solutions. The operations of Mandiant's business were integrated with our own and Mandiant's financial results were included in our consolidated financial statements as of the acquisition date.
	In March 2014, we completed our follow-on public offering in which we issued and sold 5,582,215 shares of common stock at a price of $82.00 per share. We received aggregate proceeds of $446.5 million from the sale of shares of common stock, net of underwriters’ discounts and commissions of $11.2 million, but before deducting offering expenses of approximately $2.2 million. Another 8,417,785 shares were sold by certain selling stockholders, which included 796,846 shares sold pursuant to the exercise of vested outstanding options by our employees. We did not receive any of the proceeds from the sales of shares by the selling stockholders.
	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 financial statements have been prepared on the same basis as our annual 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, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015 or for any other interim period or for any other future year. The balance sheet as of December 31, 2014 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 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, 2014 included in our Annual Report on Form 10-K, which was filed with the SEC on March 2, 2015.
	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 common and preferred stock, stock options and preferred stock warrant liability, 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, 2015, as compared to the significant accounting policies described in our Annual Report on Form 10-K for the year ended December 31, 2014.
	Recent Accounting Pronouncements
	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. The guidance is effective for us beginning in the first quarter of 2017; however, the FASB issued a proposal to have the standard take effect for reporting periods beginning after December 15, 2017 for public companies, which, if finalized, would delay the effective date to 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. We are currently evaluating the impact the adoption 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_Notes

Fair Value Measurements (Notes)	3 Months Ended
	Mar. 31, 2015
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 measured at fair value on a recurring basis using the above input categories (in thousands):
		As of March 31, 2015								As of December 31, 2014
	Description	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Cash equivalents:
	Money market funds	$	13,321	$	—	$	—	$	13,321	$	13,069	$	—	$	—	$	13,069
	U.S. Government agencies	—		8,500		—		8,500		—		12,950		—		12,950
	Total cash equivalents	13,321		8,500		—		21,821		13,069		12,950		—		26,019
	Short-term investments:
	Certificates of deposit	—		4,282		—		4,282		—		4,994		—		4,994
	Corporate notes and bonds	—		144,131		—		144,131		—		142,984		—		142,984
	U.S. Government agencies	—		112,425		—		112,425		—		107,867		—		107,867
	Total short-term investments	—		260,838		—		260,838		—		255,845		—		255,845
	Total assets measured at fair value	$	13,321	$	269,338	$	—	$	282,659	$	13,069	$	268,795	$	—	$	281,864

ShortTerm_Investments_Notes

Short-Term Investments (Notes)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Short-Term Investments	Short-Term Investments
	Our investments consisted of the following available-for-sale securities (in thousands):
		As of March 31, 2015
		Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value			Cash and cash equivalents		Short-term investment
	Certificates of deposit	$	4,280	$	3		$	(1	)	$	4,282		$	—	$	4,282
	Corporate notes and bonds	144,170		16			(55		)	144,131			—		144,131
	U.S. Government agencies	120,926		31			(32		)	120,925			8,500		112,425
	Total	$	269,376	$	50		$	(88	)	$	269,338		$	8,500	$	260,838
		As of December 31, 2014
		Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value			Cash and cash equivalents		Short-term investment
	Certificates of deposit	$	5,000	$	—		$	(6	)	$	4,994		$	—	$	4,994
	Corporate notes and bonds	143,215		4			(235		)	142,984			—		142,984
	U.S. Government agencies	121,021		1			(205		)	120,817			12,950		107,867
	Total	$	269,236	$	5		$	(446	)	$	268,795		$	12,950	$	255,845
	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, 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	$	1,159	$	(1	)	$	—		$	—		$	1,159	$	(1	)
	Corporate notes and bonds	81,750		(40		)	22,740			(15		)	104,490		(55		)
	U.S. Government agencies	82,925		(32		)	—			—			82,925		(32		)
	Total	$	165,834	$	(73	)	$	22,740		$	(15	)	$	188,574	$	(88	)
		As of December 31, 2014
		Less Than 12 Months					Greater Than 12 Months						Total
		Fair Value		Unrealized Loss			Fair Value			Unrealized Loss			Fair Value		Unrealized Loss
	Certificates of deposit	$	3,793	$	(6	)	$	—		$	—		$	3,793	$	(6	)
	Corporate notes and bonds	130,920		(235		)	—			—			130,920		(235		)
	U.S. Government agencies	109,868		(205		)	—			—			109,868		(205		)
	Total	$	244,581	$	(446	)	$	—		$	—		$	244,581	$	(446	)
	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, 2015.
	The following table summarizes the contractual maturities of our investments at March 31, 2015 (in thousands):
		Amortized Cost		Fair Value
	Due within one year	$	161,047	$	161,005
	Due within one to two years	108,329		108,333
	Total	$	269,376	$	269,338
	All available-for-sale securities have been classified as current, based on management's intent and ability to use the funds in current operations.

Property_and_Equipment_Notes

Property and Equipment (Notes)	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment
	Property and equipment, net consisted of the following as of the dates below (in thousands):
		As of March 31, 2015			As of December 31, 2014
	Computer equipment and software	$	92,150		$	85,171
	Leasehold improvements	37,344			34,522
	Furniture and fixtures	12,286			12,022
	Machinery and equipment	447			447
	Total property and equipment	142,227			132,162
	Less: accumulated depreciation	(61,197		)	(49,864		)
	Total property and equipment, net	$	81,030		$	82,298
	Depreciation and amortization expense related to property and equipment and demonstration units during the three months ended March 31, 2015 and 2014 was $14.3 million and $9.7 million, respectively.

Business_Combinations_Notes

Business Combinations (Notes)	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Business Combinations	Business Combinations
	On May 9, 2014, we acquired all outstanding shares of privately held nPulse Technologies, Inc. (“nPulse”), a performance leader in network forensics based in Charlottesville, Virginia. The acquisition of nPulse strengthens our position as a leader in advanced threat detection and incident response management solutions.
	The total purchase consideration of $56.6 million consisted of $55.2 million in cash, $0.1 million of equity awards assumed, and 54,319 shares of our common stock, with a fair value of $1.3 million which will vest upon the achievement of milestones. The number of shares was fixed at the completion of the acquisition, and is the maximum number of shares that can vest over a period of approximately three and half years from the acquisition date.
	The acquisition of nPulse 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. Under the acquisition method of accounting, the total purchase consideration is allocated to the preliminary tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values. The total purchase price 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 for up to a year following the acquisition date. Total allocation of the preliminary purchase price allocation is as follows (in thousands):
		Amount
	Net tangible liabilities assumed	$	(1,833	)
	Intangible assets	24,700
	Deferred tax asset	442
	Deferred tax liability	(8,368		)
	Goodwill	41,671
	Total preliminary purchase price allocation	$	56,612
	None of the goodwill is deductible for U.S. federal income tax purposes.
	Intangible assets consist primarily of developed technology, customer relationships and in-process research and development. Developed technology intangible includes 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 and services. Customer relationships intangible relates to nPulse’s ability to sell existing, in-process and future products and services to its existing and potential customers. The in-process research and development intangible represents the estimated fair value of acquired research projects which have not reached technological feasibility at acquisition date but are expected to be developed into products and services within one year of the acquisition date. The preliminary 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	6		$	10,100
	Customer relationships	8		8,000
	In-process research and development	N/A		6,600
	Total			$	24,700
	The results of operations of nPulse have been included in our condensed consolidated statements of operations from the acquisition date. 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
	There were no changes in the carrying amount of goodwill for the three months ended March 31, 2015.
	Purchased intangible assets consisted of the following as of the dates below (in thousands):
		As of March 31, 2015				As of December 31, 2014
	Developed technology	$	78,193			$	78,193
	Content	128,600				128,600
	Customer relationships	75,300				75,300
	Contract backlog	13,800				13,800
	Trade names	12,400				12,400
	Total intangible assets	308,293				308,293
	Less: accumulated amortization	(58,435		)		(46,668		)
	Total net intangible assets	$	249,858			$	261,625
	Amortization expense of intangible assets for the three months ended March 31, 2015 and 2014 was $11.8 million and $10.8 million, respectively.
	The expected annual amortization expense of intangible assets as of March 31, 2015 is presented below (in thousands):
	Years Ending December 31,	Amount
	2015 (remaining nine months)	$	35,297
	2016	46,448
	2017	40,503
	2018	29,346
	2019	27,574
	2020 and thereafter	70,690
	Total	$	249,858

Restructuring_Charges_Notes

Restructuring Charges (Notes)	3 Months Ended
	Mar. 31, 2015
Restructuring and Related Activities [Abstract]
Restructuring Charges	Restructuring Charges
	We initiated a series of business restructuring plans beginning in August 2014 to reduce our cost structure and improve efficiency, resulting in workforce reductions and the consolidation of certain real estate facilities. These activities were substantially complete as of December 31, 2014.
	The following table sets forth a summary of restructuring activities during the three months ended March 31, 2015 (in thousands):
		Severance and related costs		Facilities costs			Total costs
	Balance, December 31, 2014	$	—	$	765		$	765
	Provision for restructuring charges	—		—			—
	Cash payments	—		(245		)	(245		)
	Balance, March 31, 2015	$	—	$	520		$	520
	The remaining restructuring balance of $0.5 million at March 31, 2015 relates to non-cancelable lease costs, which the Company expects to pay over the terms of the related obligations through the third quarter of 2017, less sublease income.

Deferred_Revenue_Notes

Deferred Revenue (Notes)	3 Months Ended
	Mar. 31, 2015
Revenue Recognition [Abstract]
Deferred Revenue	Deferred Revenue
	Deferred revenue consisted of the following as of the dates below (in thousands):
		As of March 31, 2015		As of December 31, 2014
	Product, current	$	9,697	$	10,718
	Subscription and services, current	207,514		193,159
	Total deferred revenue, current	217,211		203,877
	Product, non-current	3,950		4,891
	Subscription and services, non-current	157,603		143,775
	Total deferred revenue, non-current	161,553		148,666
	Total deferred revenue	$	378,764	$	352,543

Commitments_and_Contingencies_

Commitments and Contingencies (Notes)	3 Months Ended
	Mar. 31, 2015
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 $3.2 million and $2.6 million for the three months ended March 31, 2015 and 2014, respectively.
	The aggregate future non-cancelable minimum rental payments on our operating leases, as of March 31, 2015, are as follows (in thousands):
	Years Ending December 31,	Amount
	2015 (remaining nine months)	$	10,782
	2016	9,706
	2017	7,985
	2018	5,351
	2019	5,385
	2020 and thereafter	11,870
	Total	$	51,079
	Total future non-cancelable minimum rental payments have not been reduced by future minimum sublease rentals totaling $1.1 million.
	We are party to letters of credit totaling $1.9 million as of March 31, 2015 and December 31, 2014, 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, 2015 and December 31, 2014, we had non-cancelable open orders of $21.6 million and $23.2 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, 2015 we have not accrued any significant costs for such non-cancelable commitments.
	Purchase Obligations
	As of March 31, 2015, we had approximately $20.9 million of non-cancelable firm purchase commitments primarily for purchases of software and services. Amounts which the Company has received delivery of the goods or services under purchase orders outstanding at March 31, 2015, are reflected in the Condensed Consolidated Balance Sheet as accounts payable or accrued liabilities, and are excluded from the $20.9 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, the members of our Board of Directors, our Chief Financial Officer, 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 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.  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. The action is purportedly brought 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. The complaint seeks, among other things, compensatory damages and attorneys’ fees and costs on behalf of the putative class. 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 complaints purport to allege claims for breach of fiduciary duty and unjust enrichment. 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.
	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, 2015, there have been no claims under any indemnification provisions.

Common_Shares_Reserved_for_Iss

Common Shares Reserved for Issuance (Notes)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Common Shares Reserved for Issuance	Common Shares Reserved for Issuance
	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, 2015 and December 31, 2014. 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. There were no shares of convertible preferred stock outstanding as of March 31, 2015 or December 31, 2014.
	As of March 31, 2015 and December 31, 2014, we had reserved shares of common stock for issuance as follows (in thousands):
		As of March 31, 2015	As of December 31, 2014
	Reserved under stock award plans	43,106	38,879
	ESPP	4,212	2,683
	Total	47,318	41,562

Equity_Award_Plans_Notes

Equity Award Plans (Notes)	3 Months Ended
	Mar. 31, 2015
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 for so long as such stock remains unvested. Approximately 19.1 million shares of our common stock were reserved for future grants as of March 31, 2015 under the 2013 Plan, including 7,642,993 shares of common stock that became available for future grants under our 2013 Plan on January 1, 2015 pursuant to provisions thereof that automatically increase the share reserve under such plan each year.
	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 4,211,761 shares of common stock were available for future issuance as of March 31, 2015 under our ESPP, including 1,528,598 shares of common stock that became available for future issuance under the ESPP on January 1, 2015 pursuant to the provisions thereof that automatically increase the share reserve under such plan each year.
	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 expected to vest and options exercisable are presented below (in thousands, except per share amounts and contractual life years):
		Options Outstanding
		Number of		Weighted-			Weighted-				Weighted-	Aggregate
		Shares		Average			Average				Average	Intrinsic
				Exercise			Grant Date				Contractual	Value
				Price			Fair Value				Life (years)
							(per share)
	Balance — December 31, 2014	18,578		$	9.13						7.4	$	445,636
	Granted	—		—			$	—
	Exercised	(2,634	)	4.51								94,769
	Cancelled	(541	)	12.52
	Balance — March 31, 2015	15,403		$	9.8						7.42	$	474,031
	Options vested and expected to vest — March 31, 2015	15,082		$	9.7						7.41	$	465,292
	Options exercisable — March 31, 2015	7,269		$	7.32						6.82	$	238,324
	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 are presented below (in thousands, except per share amounts and contractual life years):
		Number of		Weighted-			Weighted-		Aggregate
		Shares		Average			Average		Intrinsic
				Grant Date			Contractual		Value
				Fair Value			Life (years)
				(per share)
	Unvested balance — December 31, 2014	8,341					1.7		$	263,416
	Granted	3,080		$	36.97
	Vested	(839	)
	Cancelled	(646	)
	Unvested balance — March 31, 2015	9,936					1.65		389,976
	Expected to vest — March 31, 2015	9,384					1.65		$	368,305
	We issued into escrow 241,362 restricted stock awards, with an estimated fair value of $6.4 million, for certain employees from the nPulse acquisition. These awards will be released from escrow to such employees if specified performance milestones are met within approximately three and a half years from May 2014, the acquisition date. These awards are also contingent upon the related employees’ continuous employment with us, and we have determined that it is probable that such performance milestones will be met. As such, compensation expense is being recorded over the requisite service period of three and half years.
	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.
	During the three months ended March 31, 2015, there was no change to the assumptions used in the Black-Scholes option-pricing model to determine fair value of our common shares to be issued under the ESPP.
	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,
		2015			2014
	Cost of product revenue	$	268		$	145
	Cost of subscription and services revenue	6,378			3,420
	Research and development	16,035			4,603
	Sales and marketing	16,454			8,688
	General and administrative	10,740			8,338
	Total	$	49,875		$	25,194
	As of March 31, 2015, total compensation cost related to stock-based awards not yet recognized was $341.0 million, net of estimated forfeitures, which is expected to be amortized on a straight-line basis over the weighted-average remaining vesting period of approximately 3 years.

Income_Taxes_Notes

Income Taxes (Notes)	3 Months Ended
	Mar. 31, 2015
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 provision for income taxes of $1.0 million for the three months ended March 31, 2015. We recognized a benefit from income taxes of $6.0 million for the three months ended March 31, 2014. The tax provision for the three months ended March 31, 2015 is primarily due to foreign taxes and state minimum taxes. The tax benefit for the three months ended March 31, 2014 is primarily due to a decrease in the U.S. deferred tax liabilities previously established in purchase accounting due to amortization of the related intangibles and an increase in U.S. deferred tax assets primarily related to current year operating losses and stock based compensation, partially offset by foreign taxes and state minimum taxes.

Net_Loss_per_Share_Notes

Net Loss per Share (Notes)	3 Months Ended
	Mar. 31, 2015
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, and unvested restricted common stock and stock units. As we had net losses for the three months ended March 31, 2015 and 2014, 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,
		2015				2014
	Numerator:
	Net loss	$	(133,964	)		$	(101,211	)
	Denominator:
	Weighted average number of shares outstanding—basic and diluted	151,651				133,976
	Net loss per share—basic and diluted	$	(0.88	)		$	(0.76	)
	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 antidilutive (in thousands):
		As of March 31,
		2015			2014
	Options to purchase common stock	15,403			26,625
	Unvested early exercised common shares	1,959			3,793
	Unvested restricted stock awards and units	9,936			4,348
	ESPP shares	312			498

Employee_Benefit_Plan_Notes

Employee Benefit Plan (Notes)	3 Months Ended
	Mar. 31, 2015
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. In addition, until January 2015, we maintained a tax qualified plan for employees of the Mandiant subsidiary that was assumed in the Mandiant acquisition. In January 2015, the Mandiant 401(k) plan was merged into the 401(k) Plan. All participants’ interests in their deferrals are 100% vested when contributed under both 401(k) plans. We are responsible for administrative costs of the 401(k) Plan and have made no matching contributions into our 401(k) Plan since inception. The Mandiant 401(k) plan had provided for a match of 100% of the first 4% of an eligible employee’s compensation contributed. Matching contributions under the Mandiant 401(k) plan were 100% vested when made. Under both 401(k) plans, pre-tax contributions are allocated to each participant’s individual account and are then invested in selected investment alternatives according to the participants’ directions. Each 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 each 401(k) plan and earnings on those contributions are not taxable to the employees until distributed from the 401(k) plan, and all contributions are deductible by us when made. We contributed $0.7 million to the Mandiant 401(k) plan for the three months ended March 31, 2014.

Segment_Information_Notes

Segment Information (Notes)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Information	Segment 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,
		2015		2014
	Revenue:
	United States	$	89,189	$	55,728
	EMEA	16,792		9,245
	APAC	13,721		6,327
	Other	5,668		2,680
	Total revenue	$	125,370	$	73,980
	Long lived assets by geographic region based on physical location is as follows (in thousands):
		As of March 31, 2015		As of December 31, 2014
	Property and Equipment, net:
	United States	$	63,030	$	66,807
	International	18,000		15,491
	Total property and equipment, net	$	81,030	$	82,298
	For the three months ended March 31, 2015, one distributor and one reseller represented 13% and 11%, respectively, of the Company's total revenue. For the three months ended March 31, 2014, no customer represented 10% or more of the Company's total revenue. As of March 31, 2015, one reseller and one distributor represented 12% and 10%, respectively, of the Company's net accounts receivable balance. As of December 31, 2014, one distributor represented 15% of the Company's net accounts receivable balance.

Description_of_Business_and_Su1

Description of Business and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Consolidation	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 financial statements have been prepared on the same basis as our annual 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, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015 or for any other interim period or for any other future year. The balance sheet as of December 31, 2014 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 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, 2014 included in our Annual Report on Form 10-K, which was filed with the SEC on March 2, 2015.
Use of Estimates	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 common and preferred stock, stock options and preferred stock warrant liability, 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.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	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. The guidance is effective for us beginning in the first quarter of 2017; however, the FASB issued a proposal to have the standard take effect for reporting periods beginning after December 15, 2017 for public companies, which, if finalized, would delay the effective date to 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. We are currently evaluating the impact the adoption 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.
Litigation	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.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of Assets Measured at Fair Value on a Recurring Basis	The following table presents our assets measured at fair value on a recurring basis using the above input categories (in thousands):
		As of March 31, 2015								As of December 31, 2014
	Description	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Cash equivalents:
	Money market funds	$	13,321	$	—	$	—	$	13,321	$	13,069	$	—	$	—	$	13,069
	U.S. Government agencies	—		8,500		—		8,500		—		12,950		—		12,950
	Total cash equivalents	13,321		8,500		—		21,821		13,069		12,950		—		26,019
	Short-term investments:
	Certificates of deposit	—		4,282		—		4,282		—		4,994		—		4,994
	Corporate notes and bonds	—		144,131		—		144,131		—		142,984		—		142,984
	U.S. Government agencies	—		112,425		—		112,425		—		107,867		—		107,867
	Total short-term investments	—		260,838		—		260,838		—		255,845		—		255,845
	Total assets measured at fair value	$	13,321	$	269,338	$	—	$	282,659	$	13,069	$	268,795	$	—	$	281,864

ShortTerm_Investments_Tables

Short-Term Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Summary of Investments	Our investments consisted of the following available-for-sale securities (in thousands):
		As of March 31, 2015
		Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value			Cash and cash equivalents		Short-term investment
	Certificates of deposit	$	4,280	$	3		$	(1	)	$	4,282		$	—	$	4,282
	Corporate notes and bonds	144,170		16			(55		)	144,131			—		144,131
	U.S. Government agencies	120,926		31			(32		)	120,925			8,500		112,425
	Total	$	269,376	$	50		$	(88	)	$	269,338		$	8,500	$	260,838
		As of December 31, 2014
		Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value			Cash and cash equivalents		Short-term investment
	Certificates of deposit	$	5,000	$	—		$	(6	)	$	4,994		$	—	$	4,994
	Corporate notes and bonds	143,215		4			(235		)	142,984			—		142,984
	U.S. Government agencies	121,021		1			(205		)	120,817			12,950		107,867
	Total	$	269,236	$	5		$	(446	)	$	268,795		$	12,950	$	255,845
Summary of Unrealized Losses on Investments	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, 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	$	1,159	$	(1	)	$	—		$	—		$	1,159	$	(1	)
	Corporate notes and bonds	81,750		(40		)	22,740			(15		)	104,490		(55		)
	U.S. Government agencies	82,925		(32		)	—			—			82,925		(32		)
	Total	$	165,834	$	(73	)	$	22,740		$	(15	)	$	188,574	$	(88	)
		As of December 31, 2014
		Less Than 12 Months					Greater Than 12 Months						Total
		Fair Value		Unrealized Loss			Fair Value			Unrealized Loss			Fair Value		Unrealized Loss
	Certificates of deposit	$	3,793	$	(6	)	$	—		$	—		$	3,793	$	(6	)
	Corporate notes and bonds	130,920		(235		)	—			—			130,920		(235		)
	U.S. Government agencies	109,868		(205		)	—			—			109,868		(205		)
	Total	$	244,581	$	(446	)	$	—		$	—		$	244,581	$	(446	)
Summary of Contractual Maturities	The following table summarizes the contractual maturities of our investments at March 31, 2015 (in thousands):
		Amortized Cost		Fair Value
	Due within one year	$	161,047	$	161,005
	Due within one to two years	108,329		108,333
	Total	$	269,376	$	269,338

Property_and_Equipment_Tables

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment, net consisted of the following as of the dates below (in thousands):
		As of March 31, 2015			As of December 31, 2014
	Computer equipment and software	$	92,150		$	85,171
	Leasehold improvements	37,344			34,522
	Furniture and fixtures	12,286			12,022
	Machinery and equipment	447			447
	Total property and equipment	142,227			132,162
	Less: accumulated depreciation	(61,197		)	(49,864		)
	Total property and equipment, net	$	81,030		$	82,298

Business_Combinations_Tables

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Schedule of Preliminary Purchase Price Allocation	Total allocation of the preliminary purchase price allocation is as follows (in thousands):
		Amount
	Net tangible liabilities assumed	$	(1,833	)
	Intangible assets	24,700
	Deferred tax asset	442
	Deferred tax liability	(8,368		)
	Goodwill	41,671
	Total preliminary purchase price allocation	$	56,612
Schedule of Preliminary Estimated Useful Life and Fair Values of the Identifiable Intangible Assets	The preliminary 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	6		$	10,100
	Customer relationships	8		8,000
	In-process research and development	N/A		6,600
	Total			$	24,700
Schedule of Purchased Intangible Assets	Purchased intangible assets consisted of the following as of the dates below (in thousands):
		As of March 31, 2015				As of December 31, 2014
	Developed technology	$	78,193			$	78,193
	Content	128,600				128,600
	Customer relationships	75,300				75,300
	Contract backlog	13,800				13,800
	Trade names	12,400				12,400
	Total intangible assets	308,293				308,293
	Less: accumulated amortization	(58,435		)		(46,668		)
	Total net intangible assets	$	249,858			$	261,625
Schedule of Expected Annual Amortization Expense of Intangible Assets	The expected annual amortization expense of intangible assets as of March 31, 2015 is presented below (in thousands):
	Years Ending December 31,	Amount
	2015 (remaining nine months)	$	35,297
	2016	46,448
	2017	40,503
	2018	29,346
	2019	27,574
	2020 and thereafter	70,690
	Total	$	249,858

Restructuring_Charges_Tables

Restructuring Charges (Tables)	3 Months Ended
	Mar. 31, 2015
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, 2015 (in thousands):
		Severance and related costs		Facilities costs			Total costs
	Balance, December 31, 2014	$	—	$	765		$	765
	Provision for restructuring charges	—		—			—
	Cash payments	—		(245		)	(245		)
	Balance, March 31, 2015	$	—	$	520		$	520

Deferred_Revenue_Tables

Deferred Revenue (Tables)	3 Months Ended
	Mar. 31, 2015
Revenue Recognition [Abstract]
Schedule of Deferred Revenue	Deferred revenue consisted of the following as of the dates below (in thousands):
		As of March 31, 2015		As of December 31, 2014
	Product, current	$	9,697	$	10,718
	Subscription and services, current	207,514		193,159
	Total deferred revenue, current	217,211		203,877
	Product, non-current	3,950		4,891
	Subscription and services, non-current	157,603		143,775
	Total deferred revenue, non-current	161,553		148,666
	Total deferred revenue	$	378,764	$	352,543

Commitments_and_Contingencies_1

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	The aggregate future non-cancelable minimum rental payments on our operating leases, as of March 31, 2015, are as follows (in thousands):
	Years Ending December 31,	Amount
	2015 (remaining nine months)	$	10,782
	2016	9,706
	2017	7,985
	2018	5,351
	2019	5,385
	2020 and thereafter	11,870
	Total	$	51,079

Common_Shares_Reserved_for_Iss1

Common Shares Reserved for Issuance (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Issuance	As of March 31, 2015 and December 31, 2014, we had reserved shares of common stock for issuance as follows (in thousands):
		As of March 31, 2015	As of December 31, 2014
	Reserved under stock award plans	43,106	38,879
	ESPP	4,212	2,683
	Total	47,318	41,562

Equity_Award_Plans_Tables

Equity Award Plans (Tables)	3 Months Ended
	Mar. 31, 2015
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 expected to vest and options exercisable are presented below (in thousands, except per share amounts and contractual life years):
		Options Outstanding
		Number of		Weighted-			Weighted-				Weighted-	Aggregate
		Shares		Average			Average				Average	Intrinsic
				Exercise			Grant Date				Contractual	Value
				Price			Fair Value				Life (years)
							(per share)
	Balance — December 31, 2014	18,578		$	9.13						7.4	$	445,636
	Granted	—		—			$	—
	Exercised	(2,634	)	4.51								94,769
	Cancelled	(541	)	12.52
	Balance — March 31, 2015	15,403		$	9.8						7.42	$	474,031
	Options vested and expected to vest — March 31, 2015	15,082		$	9.7						7.41	$	465,292
	Options exercisable — March 31, 2015	7,269		$	7.32						6.82	$	238,324
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 are presented below (in thousands, except per share amounts and contractual life years):
		Number of		Weighted-			Weighted-		Aggregate
		Shares		Average			Average		Intrinsic
				Grant Date			Contractual		Value
				Fair Value			Life (years)
				(per share)
	Unvested balance — December 31, 2014	8,341					1.7		$	263,416
	Granted	3,080		$	36.97
	Vested	(839	)
	Cancelled	(646	)
	Unvested balance — March 31, 2015	9,936					1.65		389,976
	Expected to vest — March 31, 2015	9,384					1.65		$	368,305
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,
		2015			2014
	Cost of product revenue	$	268		$	145
	Cost of subscription and services revenue	6,378			3,420
	Research and development	16,035			4,603
	Sales and marketing	16,454			8,688
	General and administrative	10,740			8,338
	Total	$	49,875		$	25,194

Net_Loss_per_Share_Tables

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2015
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,
		2015				2014
	Numerator:
	Net loss	$	(133,964	)		$	(101,211	)
	Denominator:
	Weighted average number of shares outstanding—basic and diluted	151,651				133,976
	Net loss per share—basic and diluted	$	(0.88	)		$	(0.76	)
Schedule of Outstanding Options and Unvested Shares Excluded from Diluted Net Loss Per Share Computation	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 antidilutive (in thousands):
		As of March 31,
		2015			2014
	Options to purchase common stock	15,403			26,625
	Unvested early exercised common shares	1,959			3,793
	Unvested restricted stock awards and units	9,936			4,348
	ESPP shares	312			498

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2015
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,
		2015		2014
	Revenue:
	United States	$	89,189	$	55,728
	EMEA	16,792		9,245
	APAC	13,721		6,327
	Other	5,668		2,680
	Total revenue	$	125,370	$	73,980
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, 2015		As of December 31, 2014
	Property and Equipment, net:
	United States	$	63,030	$	66,807
	International	18,000		15,491
	Total property and equipment, net	$	81,030	$	82,298

Description_of_Business_and_Su2

Description of Business and Summary of Significant Accounting Policies - Narrative (Details) (USD $)	1 Months Ended	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Common stock issued and sold (shares)	5,582,215
Price per share (usd per share)	$82
Proceeds from initial public offering, net of underwriting discounts and commissions	$446.50
Underwriters discounts and commissions	11.2
Offering expenses	$2.20
Common stock sold from certain selling stockholders (shares)	8,417,785
Exercised (shares)	796,846	2,634,000

Fair_Value_Measurements_Schedu

Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	$21,821	$26,019
Total short-term investments	260,838	255,845
Total assets measured at fair value	282,659	281,864
Certificates of deposit [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	4,282	4,994
Corporate notes and bonds [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	144,131	142,984
U.S. Government agencies [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	112,425	107,867
Money market funds [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	13,321	13,069
U.S. Government agencies [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	8,500	12,950
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	13,321	13,069
Total short-term investments	0	0
Total assets measured at fair value	13,321	13,069
Level 1 [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 1 [Member] | Corporate notes and bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 1 [Member] | U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 1 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	13,321	13,069
Level 1 [Member] | U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	8,500	12,950
Total short-term investments	260,838	255,845
Total assets measured at fair value	269,338	268,795
Level 2 [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	4,282	4,994
Level 2 [Member] | Corporate notes and bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	144,131	142,984
Level 2 [Member] | U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	112,425	107,867
Level 2 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0	0
Level 2 [Member] | U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	8,500	12,950
Level 3 [Member]
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
Level 3 [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 3 [Member] | Corporate notes and bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 3 [Member] | U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0	0
Level 3 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0	0
Level 3 [Member] | U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	$0	$0

ShortTerm_Investments_Summary_

Short-Term Investments - Summary of Investments (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents	$136,776	$146,363	$441,270	$173,918
Short-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	269,376	269,236
Gross Unrealized Gains	50	5
Gross Unrealized Losses	-88	-446
Estimated Fair Value	269,338	268,795
Cash and cash equivalents	8,500	12,950
Short-term investment	260,838	255,845
Short-term investments [Member] | Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,280	5,000
Gross Unrealized Gains	3	0
Gross Unrealized Losses	-1	-6
Estimated Fair Value	4,282	4,994
Cash and cash equivalents	0	0
Short-term investment	4,282	4,994
Short-term investments [Member] | Corporate notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	144,170	143,215
Gross Unrealized Gains	16	4
Gross Unrealized Losses	-55	-235
Estimated Fair Value	144,131	142,984
Cash and cash equivalents	0	0
Short-term investment	144,131	142,984
Short-term investments [Member] | U.S. Government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	120,926	121,021
Gross Unrealized Gains	31	1
Gross Unrealized Losses	-32	-205
Estimated Fair Value	120,925	120,817
Cash and cash equivalents	8,500	12,950
Short-term investment	$112,425	$107,867

ShortTerm_Investments_Summary_1

Short-Term Investments - Summary of Unrealized Losses on Investments (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	$165,834	$244,581
Unrealized Loss, Less Than 12 Months	-73	-446
Fair Value, Greater Than 12 Months	22,740	0
Unrealized Loss, Greater Than 12 Months	-15	0
Fair Value	188,574	244,581
Unrealized Loss	-88	-446
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	1,159	3,793
Unrealized Loss, Less Than 12 Months	-1	-6
Fair Value, Greater Than 12 Months	0	0
Unrealized Loss, Greater Than 12 Months	0	0
Fair Value	1,159	3,793
Unrealized Loss	-1	-6
Corporate notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	81,750	130,920
Unrealized Loss, Less Than 12 Months	-40	-235
Fair Value, Greater Than 12 Months	22,740	0
Unrealized Loss, Greater Than 12 Months	-15	0
Fair Value	104,490	130,920
Unrealized Loss	-55	-235
U.S. Government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	82,925	109,868
Unrealized Loss, Less Than 12 Months	-32	-205
Fair Value, Greater Than 12 Months	0	0
Unrealized Loss, Greater Than 12 Months	0	0
Fair Value	82,925	109,868
Unrealized Loss	($32)	($205)

ShortTerm_Investments_Narrativ

Short-Term Investments - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Other than temporary impairment	$0

ShortTerm_Investments_Summary_2

Short-Term Investments - Summary of Contractual Maturities (Details) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Due within one year, amortized cost	$161,047
Due within one to two years, amortized cost	108,329
Total, amortized cost	269,376
Due within one year, fair value	161,005
Due within one to two years, fair value	108,333
Total, fair value	$269,338

Property_and_Equipment_Schedul

Property and Equipment - Schedule of Property and Equipment (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Total property and equipment	$142,227	$132,162
Less: accumulated depreciation	-61,197	-49,864
Total property and equipment, net	81,030	82,298
Computer equipment and software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	92,150	85,171
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	37,344	34,522
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	12,286	12,022
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$447	$447

Property_and_Equipment_Narrati

Property and Equipment - Narrative (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$14.30	$9.70

Business_Combinations_Narrativ

Business Combinations - Narrative (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	9-May-14
Business Acquisition [Line Items]
Changes in carrying amount of goodwill	$0
Amortization of intangible assets	11,800,000	10,800,000
nPulse Technologies [Member]
Business Acquisition [Line Items]
Total purchase consideration			56,600,000
Purchase consideration, cash paid			55,200,000
Purchase consideration, fair value of common stock			1,300,000
Performance milestone determination period			3 years 6 months
Goodwill deductible for U.S. federal income tax purposes			0
Unvested stock options and restricted stock [Member] | nPulse Technologies [Member]
Business Acquisition [Line Items]
Purchase consideration, equity awards assumed			100,000
General and administrative [Member] | nPulse Technologies [Member]
Business Acquisition [Line Items]
Acquisition costs			$500,000
Maximum [Member] | nPulse Technologies [Member]
Business Acquisition [Line Items]
Purchase consideration, shares issued for acquisition (shares)			54,319

Business_Combinations_Schedule

Business Combinations - Schedule of Preliminary Purchase Price Allocation (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	9-May-14
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Goodwill	$750,288	$750,288
nPulse Technologies [Member]
Business Acquisition [Line Items]
Net tangible liabilities assumed			-1,833
Intangible assets			24,700
Deferred tax asset			442
Deferred tax liability			-8,368
Goodwill			41,671
Total preliminary purchase price allocation			$56,612

Business_Combinations_Schedule1

Business Combinations - Schedule of Preliminary Estimated Useful Life and Fair Values of the Identifiable Intangible Assets (Details) (nPulse Technologies [Member], USD $)	0 Months Ended
In Thousands, unless otherwise specified	9-May-14	9-May-14
Finite-Lived Intangible Assets [Line Items]
Total	$24,700	$24,700
In Process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite lived acquired assets	6,600	6,600
Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Finite lived acquired assets, useful life	6 years
Finite lived acquired assets	10,100	10,100
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite lived acquired assets, useful life	8 years
Finite lived acquired assets	$8,000	$8,000

Business_Combinations_Schedule2

Business Combinations - Schedule of Purchased Intangible Assets (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]
Total intangible assets	$308,293	$308,293
Less: accumulated amortization	-58,435	-46,668
Total net intangible assets	249,858	261,625
Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Total intangible assets	78,193	78,193
Content [Member]
Finite-Lived Intangible Assets [Line Items]
Total intangible assets	128,600	128,600
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Total intangible assets	75,300	75,300
Contract backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Total intangible assets	13,800	13,800
Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Total intangible assets	$12,400	$12,400

Business_Combinations_Schedule3

Business Combinations - Schedule of Expected Annual Amortization Expense of Intangible Assets (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Business Combinations [Abstract]
2015 (remaining nine months)	$35,297
2016	46,448
2017	40,503
2018	29,346
2019	27,574
2020 and thereafter	70,690
Total net intangible assets	$249,858	$261,625

Restructuring_Charges_Summary_

Restructuring Charges - Summary of Restructuring Activities (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Restructuring Reserve [Roll Forward]
Balance, December 31, 2014	$765
Provision for restructuring charges	0
Cash payments	-245
Balance, March 31, 2015	520
Severance and related costs [Member]
Restructuring Reserve [Roll Forward]
Balance, December 31, 2014	0
Provision for restructuring charges	0
Cash payments	0
Balance, March 31, 2015	0
Facilities costs [Member]
Restructuring Reserve [Roll Forward]
Balance, December 31, 2014	765
Provision for restructuring charges	0
Cash payments	-245
Balance, March 31, 2015	$520

Restructuring_Charges_Narrativ

Restructuring Charges - Narrative (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Restructuring and Related Activities [Abstract]
Restructuring reserve	$520	$765

Deferred_Revenue_Schedule_of_D

Deferred Revenue - Schedule of Deferred Revenue (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	$217,211	$203,877
Total deferred revenue, non-current	161,553	148,666
Total deferred revenue	378,764	352,543
Product [Member]
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	9,697	10,718
Total deferred revenue, non-current	3,950	4,891
Subscription and services [Member]
Deferred Revenue Arrangement [Line Items]
Total deferred revenue, current	207,514	193,159
Total deferred revenue, non-current	$157,603	$143,775

Commitments_and_Contingencies_2

Commitments and Contingencies - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
	claim
Long-term Purchase Commitment [Line Items]
Rent expense	$3,200,000	$2,600,000
Future minimum sublease rentals	1,100,000
Letters of credit available	1,900,000		1,900,000
Amount drawn against letters of credit	0
Non-cancellable open orders	21,600,000		23,200,000
Number of claims	0
Software and Services [Member]
Long-term Purchase Commitment [Line Items]
Non-cancellable open orders	$20,900,000

Commitments_and_Contingencies_3

Commitments and Contingencies - Schedule of Future Minimum Rental Payments for Operating Leases (Details) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
2015 (remaining nine months)	$10,782
2016	9,706
2017	7,985
2018	5,351
2019	5,385
2020 and thereafter	11,870
Total	$51,079

Common_Shares_Reserved_for_Iss2

Common Shares Reserved for Issuance - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
	vote_per_share
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)	$0.00	$0.00
Voting right per common share	1
Convertible preferred stock [Member]
Class of Stock [Line Items]
Convertible preferred stock outstanding (shares)	0	0

Common_Shares_Reserved_for_Iss3

Common Shares Reserved for Issuance - Schedule of Reserved Shares of Common Stock for Issuance (Details)	Mar. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Shares reserved for future issuance (shares)	47,318,000	41,562,000
ESPP [Member]
Class of Stock [Line Items]
Shares reserved for future issuance (shares)	4,212,000	2,683,000
Reserved under stock award plans [Member]
Class of Stock [Line Items]
Shares reserved for future issuance (shares)	43,106,000	38,879,000

Equity_Award_Plans_Narrative_D

Equity Award Plans - Narrative (Details) (USD $)	3 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015	Jan. 01, 2015	9-May-14	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance (shares)	47,318,000			41,562,000
Compensation cost not yet recognized	$341
Compensation cost not yet recognized, period for recognition	3 years
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance (shares)	4,211,761
Acquisition price at lower of fair market value, percentage	85.00%
Additional shares authorized (shares)		1,528,598
2013 Plan [Member]
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)	19,100,000
Shares available for future grants (shares)		7,642,993
Minimum [Member] | 2013 Plan [Member] | Employee stock option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value, percentage	100.00%
nPulse Technologies [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance milestone determination period			3 years 6 months
nPulse Technologies [Member] | Performance shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued for acquisition (shares)			241,362
Contingent obligation, employee performance award			6.4

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 $)	1 Months Ended	3 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options outstanding (shares)		18,578,000
Granted (shares)		0
Exercised (shares)	-796,846	-2,634,000
Cancelled (shares)		-541,000
Ending balance, options outstanding (shares)		15,403,000	18,578,000
Option vested and expected to vest (shares)		15,082,000
Option exercisable (shares)		7,269,000
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)		$9.13
Granted, weighted average exercise price (usd per share)		$0
Exercised, weighted average exercise price (usd per share)		$4.51
Cancelled, weighted average exercise price (usd per share)		$12.52
Ending balance, weighted average exercise price (usd per share)		$9.80	$9.13
Option vested and expected to vest, weighted average exercise price (usd per share)		$9.70
Option exercisable, weighted average exercise price (usd per share)		$7.32
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		7 years 5 months 1 day	7 years 4 months 24 days
Ending balance, options outstanding, weighted average contractual life		7 years 5 months 1 day	7 years 4 months 24 days
Option vested and expected to vest, weighted average contractual life		7 years 4 months 28 days
Option exercisable, weighted average contractual life		6 years 9 months 26 days
Beginning balance, options outstanding, aggregate intrinsic value		$445,636
Exercised, aggregate intrinsic value		94,769
Ending balance, options outstanding, aggregate intrinsic value		474,031	445,636
Option vested and expected to vest, aggregate intrinsic value		465,292
Option exercisable, aggregate intrinsic value		$238,324

Equity_Award_Plans_Summary_of_1

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) (Restricted Stock Awards and Restricted Stock Units [Member], USD $)	3 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Restricted Stock Awards and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Beginning balance, unvested (shares)	8,341
Granted (shares)	3,080
Vested (shares)	-839
Cancelled (shares)	-646
Ending balance, unvested (shares)	9,936	8,341
Expected to vest (shares)	9,384
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted- Average Grant Date Fair Value (per share)	$36.97
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 24 days	1 year 8 months 12 days
Ending balance, weighted-average remaining contractual term	1 year 7 months 24 days	1 year 8 months 12 days
Expected to vest, weighted-average remaining contractual term	1 year 7 months 24 days
Beginning balance, aggregate intrinsic value	$263,416
Ending balance, aggregate intrinsic value	389,976	263,416
Expected to vest, aggregate intrinsic value	$368,305

Equity_Award_Plans_Schedule_of

Equity Award Plans - Schedule of Stock-Based Compensation Expense Related to Stock Options, ESPP and Restricted Stock Units and Awards (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$49,875	$25,194
Cost of product revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	268	145
Cost of subscription and services revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	6,378	3,420
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	16,035	4,603
Sales and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	16,454	8,688
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$10,740	$8,338

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Tax Disclosure [Abstract]
Provision for (benefit from) income taxes	$977	($6,042)

Net_Loss_per_Share_Schedule_of

Net Loss per Share - Schedule of Computation of Net Loss Per Common Share (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Net loss	($133,964)	($101,211)
Denominator:
Weighted average number of shares outstanding—basic and diluted (shares)	151,651	133,976
Net loss per share—basic and diluted (usd per share)	($0.88)	($0.76)

Net_Loss_per_Share_Schedule_of1

Net Loss per Share - Schedule of Outstanding Options and Unvested Shares Excluded from Diluted Net Loss Per Share Computation (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Option to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	15,403	26,625
Unvested early exercised common shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	1,959	3,793
Unvested restricted stock awards and units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	9,936	4,348
ESPP shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from net loss per share (shares)	312	498

Employee_Benefit_Plan_Narrativ

Employee Benefit Plan - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Employer contributions vested percentage	100.00%
Employer contributions to 401(k)	0
Mandiant, Inc. [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions vested percentage	100.00%
Employer contributions to 401(k)		$700,000
Employers match	100.00%
Employees contribution	4.00%

Segment_Information_Schedule_o

Segment Information - Schedule of Revenue by Geographic Region (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$125,370	$73,980
Operating segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	125,370	73,980
Operating segments [Member] | United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	89,189	55,728
Operating segments [Member] | EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	16,792	9,245
Operating segments [Member] | APAC [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	13,721	6,327
Operating segments [Member] | Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$5,668	$2,680

Segment_Information_Summary_of

Segment Information - Summary of Long lived Assets by Geographic Region Based on Physical Location (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Entity Location [Line Items]
Total property and equipment, net	$81,030	$82,298
United States [Member]
Entity Location [Line Items]
Total property and equipment, net	63,030	66,807
International [Member]
Entity Location [Line Items]
Total property and equipment, net	$18,000	$15,491

Segment_Information_Narrative_

Segment Information - Narrative (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
	reporting_segment	customer	customer
Revenue, Major Customer [Line Items]
Number of reportable segment and operating unit structure	1
Customer concentration risk [Member] | Sales revenue, net [Member]
Revenue, Major Customer [Line Items]
Number of major customers		0
Customer concentration risk [Member] | Distributor [Member] | Sales revenue, net [Member]
Revenue, Major Customer [Line Items]
Number of major customers	1
Concentration risk percentage	13.00%
Customer concentration risk [Member] | Distributor [Member] | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Number of major customers	1		1
Concentration risk percentage	10.00%		15.00%
Customer concentration risk [Member] | Reseller [Member] | Sales revenue, net [Member]
Revenue, Major Customer [Line Items]
Number of major customers	1
Concentration risk percentage	11.00%
Customer concentration risk [Member] | Reseller [Member] | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Number of major customers	1
Concentration risk percentage	12.00%