Proofpoint (PFPT) 10-Q 29 Jul 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	6 Months Ended
	Jun. 30, 2019	Jul. 19, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	PFPT
Entity Registrant Name	PROOFPOINT INC.
Entity Central Index Key (CIK)	0001212458
Current Fiscal Year End Date	--12-31
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		56,069,733
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-35506
Entity Tax Identification Number	510414846
Entity Address, Address Line One	892 Ross Drive
Entity Address, City or Town	Sunnyvale
Entity Address, State or Province	California
Entity Address, Postal Zip Code	94089
City Area Code	408
Local Phone Number	517-4710

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 149,697	$ 185,392
Short-term investments	33,008	46,307
Accounts receivable, net	170,998	199,194
Inventory	356	481
Deferred product costs	1,902	1,800
Deferred commissions	40,208	37,391
Prepaid expenses and other current assets	21,300	16,872
Total current assets	417,469	487,437
Property and equipment, net	70,688	70,627
Operating lease right-of-use assets	52,156
Long-term deferred product costs	296	303
Goodwill	543,143	460,425
Intangible assets, net	136,207	136,645
Long-term deferred commissions	74,479	69,989
Other assets	15,426	7,592
Total assets	1,309,864	1,233,018
Current liabilities:
Accounts payable	18,567	20,237
Accrued liabilities	71,336	90,719
Deferred rent		829
Operating lease liabilities	22,510
Deferred revenue	515,048	490,296
Total current liabilities	627,461	602,081
Long-term deferred rent		3,757
Long-term operating lease liabilities	34,461
Other long-term liabilities	9,223	6,812
Long-term deferred revenue	113,431	107,834
Total liabilities	784,576	720,484
Commitments and contingencies (Note 7)
Stockholders’ equity:
Convertible preferred stock, $0.0001 par value; 5,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.0001 par value; 200,000 shares authorized; 56,043 and 55,149 shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively	6	6
Additional paid-in capital	1,177,800	1,107,953
Accumulated other comprehensive income (loss)	2	(7)
Accumulated deficit	(652,520)	(595,418)
Total stockholders’ equity	525,288	512,534
Total liabilities and stockholders’ equity	$ 1,309,864	$ 1,233,018

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Number of shares of common stock reserved for future issuance
Common Stock, Shares Authorized	200,000,000	200,000,000
Common stock issued (in shares)	56,043,000	55,149,000
Common stock outstanding (in shares)	56,043,000	55,149,000
Par value of common stock (USD per share)	$ 0.0001	$ 0.0001

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue:
Total revenue		$ 214,439	$ 171,875	$ 417,376	$ 334,336
Cost of revenue:
Total cost of revenue	[1],[2]	57,828	50,772	113,071	97,829
Gross profit		156,611	121,103	304,305	236,507
Operating expense:
Research and development	[1],[2]	55,185	47,527	108,434	91,259
Sales and marketing	[1],[2]	102,837	84,911	199,841	162,808
General and administrative	[1],[2]	27,881	19,029	53,706	36,554
Total operating expense	[1],[2]	185,903	151,467	361,981	290,621
Operating loss		(29,292)	(30,364)	(57,676)	(54,114)
Interest income (expense)		1,068	(3,187)	2,246	(6,008)
Other expense, net		(409)	(633)	(861)	(290)
Loss before income taxes		(28,633)	(34,184)	(56,291)	(60,412)
(Provision for) benefit from income taxes		(280)	(114)	(900)	13,958
Net loss		$ (28,913)	$ (34,298)	$ (57,191)	$ (46,454)
Net loss per share, basic and diluted		$ (0.52)	$ (0.67)	$ (1.03)	$ (0.92)
Weighted average shares outstanding, basic and diluted		55,768	50,935	55,553	50,721
Subscription
Revenue:
Total revenue		$ 210,780	$ 169,019	$ 410,364	$ 327,806
Cost of revenue:
Total cost of revenue	[1],[2]	50,648	45,618	98,900	87,816
Hardware and Service
Revenue:
Total revenue		3,659	2,856	7,012	6,530
Cost of revenue:
Total cost of revenue	[1],[2]	$ 7,180	$ 5,154	$ 14,171	$ 10,013
[1]	(1) Includes stock-based compensation expense as follows: Cost of subscription revenue $ 4,269 $ 3,448 $ 8,144 $ 6,899 Cost of hardware and services revenue $ 1,054 $ 571 $ 1,960 $ 1,162 Research and development $ 12,522 $ 9,986 $ 24,021 $ 20,021 Sales and marketing $ 15,799 $ 12,382 $ 29,553 $ 23,884 General and administrative $ 12,006 $ 7,410 $ 22,993 $ 12,903
[2]	(2) Includes intangible amortization expense as follows: Cost of subscription revenue $ 7,505 $ 7,244 $ 14,267 $ 13,020 Research and development $ — $ 15 $ — $ 30 Sales and marketing $ 3,634 $ 3,982 $ 7,171 $ 6,397

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Intangible amortization expense	$ 11,139	$ 11,241	$ 21,438	$ 19,447
Cost of subscription revenue
Stock-based compensation expense	4,269	3,448	8,144	6,899
Intangible amortization expense	7,505	7,244	14,267	13,020
Cost of hardware and services revenue
Stock-based compensation expense	1,054	571	1,960	1,162
Research and development
Stock-based compensation expense	12,522	9,986	24,021	20,021
Intangible amortization expense		15		30
Sales and marketing
Stock-based compensation expense	15,799	12,382	29,553	23,884
Intangible amortization expense	3,634	3,982	7,171	6,397
General and administrative
Stock-based compensation expense	$ 12,006	$ 7,410	$ 22,993	$ 12,903

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (28,913)	$ (34,298)	$ (57,191)	$ (46,454)
Other comprehensive income, net of tax:
Unrealized gain on short-term investments, net	1	1	9	8
Comprehensive loss	$ (28,912)	$ (34,297)	$ (57,182)	$ (46,446)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adjustment from adoption | ASU 2016-16	$ (3,216)	$ 0	$ 0	$ 0	$ (3,216)
Beginning balance at Dec. 31, 2017	299,115	$ 5	787,572	(9)	(488,453)
Beginning balance (shares) at Dec. 31, 2017		50,325
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(46,454)	$ 0	0	0	(46,454)
Unrealized gain on short-term investments	8	0	0	8	0
Stock-based compensation expense	60,018	0	60,018	0	0
Common stock issued	21,870	$ 0	21,870	0	0
Common stock issued (shares)		1,174
Tax withholding upon vesting of restricted stock awards	(34,304)	$ 0	(34,304)	0	0
Tax withholding upon vesting of restricted stock awards (shares)		(308)
Ending balance at Jun. 30, 2018	297,037	$ 5	835,156	(1)	(538,123)
Ending balance (shares) at Jun. 30, 2018		51,191
Beginning balance at Mar. 31, 2018	303,694	$ 5	807,516	(2)	(503,825)
Beginning balance (shares) at Mar. 31, 2018		50,813
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(34,298)	$ 0	0	0	(34,298)
Unrealized gain on short-term investments	1	0	0	1	0
Stock-based compensation expense	30,631	0	30,631	0	0
Common stock issued	10,322	$ 0	10,322	0	0
Common stock issued (shares)		487
Tax withholding upon vesting of restricted stock awards	(13,313)	$ 0	(13,313)	0	0
Tax withholding upon vesting of restricted stock awards (shares)		(109)
Ending balance at Jun. 30, 2018	297,037	$ 5	835,156	(1)	(538,123)
Ending balance (shares) at Jun. 30, 2018		51,191
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adjustment from adoption | ASC 842	89	$ 0	0	0	89
Beginning balance at Dec. 31, 2018	512,534	$ 6	1,107,953	(7)	(595,418)
Beginning balance (shares) at Dec. 31, 2018		55,149
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(57,191)	$ 0	0	0	(57,191)
Unrealized gain on short-term investments	9	0	0	9	0
Stock-based compensation expense	76,942	0	76,942	0	0
Acquisition of businesses (Note 3)	446	$ 0	446	0	0
Acquisition of businesses (shares)		72
Common stock issued	27,343	$ 0	27,343	0	0
Common stock issued (shares)		1,130
Tax withholding upon vesting of restricted stock awards	(34,884)	$ 0	(34,884)	0	0
Tax withholding upon vesting of restricted stock awards (shares)		(308)
Ending balance at Jun. 30, 2019	525,288	$ 6	1,177,800	2	(652,520)
Ending balance (shares) at Jun. 30, 2019		56,043
Beginning balance at Mar. 31, 2019	507,111	$ 6	1,130,711	1	(623,607)
Beginning balance (shares) at Mar. 31, 2019		55,607
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(28,913)	$ 0	0	0	(28,913)
Unrealized gain on short-term investments	1	0	0	1	0
Stock-based compensation expense	42,207	0	42,207	0	0
Acquisition of businesses (Note 3)	446	$ 0	446	0	0
Acquisition of businesses (shares)		72
Common stock issued	13,587	$ 0	13,587	0	0
Common stock issued (shares)		442
Tax withholding upon vesting of restricted stock awards	(9,151)	$ 0	(9,151)	0	0
Tax withholding upon vesting of restricted stock awards (shares)		(78)
Ending balance at Jun. 30, 2019	$ 525,288	$ 6	$ 1,177,800	$ 2	$ (652,520)
Ending balance (shares) at Jun. 30, 2019		56,043

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net loss	$ (57,191)	$ (46,454)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	38,237	34,878
Stock-based compensation	86,671	64,869
Change in fair value of contingent consideration	0	(79)
Amortization of debt issuance costs and accretion of debt discount	0	6,153
Amortization of deferred commissions	23,671	16,708
Amortization of operating lease right-of-use assets	11,347	0
Deferred income taxes	(610)	(14,896)
Other	967	820
Changes in assets and liabilities:
Accounts receivable	27,860	(23,025)
Inventory	124	330
Deferred product costs	(95)	(253)
Deferred commissions	(30,978)	(21,929)
Prepaid expenses	(7,695)	(2,614)
Other current assets	459	1,657
Long-term assets	(623)	350
Accounts payable	(3,166)	4,210
Accrued liabilities	(10,371)	(4,498)
Deferred rent	0	61
Operating lease liabilities	(11,448)	0
Deferred revenue	30,350	48,698
Net cash provided by operating activities	97,509	64,986
Cash flows from investing activities
Proceeds from maturities of short-term investments	55,049	37,432
Proceeds from sales of short-term investments	0	11,931
Purchase of short-term investments	(41,768)	(23,694)
Purchase of property and equipment	(13,850)	(16,611)
Receipt from escrow account	0	555
Acquisition of business, net of cash acquired	(104,503)	(223,786)
Net cash used in investing activities	(105,072)	(214,173)
Cash flows from financing activities
Proceeds from issuance of common stock	14,691	13,001
Withholding taxes related to restricted stock net share settlement	(35,005)	(34,640)
Repayments of equipment loans and capital lease obligations	0	(16)
Contingent consideration payment	0	(555)
Net cash used in financing activities	(20,314)	(22,210)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	79	(213)
Net decrease in cash, cash equivalents and restricted cash	(27,798)	(171,610)
Cash, cash equivalents and restricted cash
Beginning of period	186,152	286,660
End of period	158,354	115,050
Supplemental disclosure of noncash investing and financing information
Unpaid purchases of property and equipment and asset retirement obligations	5,681	3,850
Operating lease right-of-use assets exchanged for lease obligations	3,979	0
Liability awards converted to equity	12,651	8,870
Reconciliation of cash, cash equivalents and restricted cash as shown in the consolidated statement of cash flows
Cash and cash equivalents	149,697	114,225
Restricted cash included in prepaid expenses and other current assets	3,414	337
Restricted cash included in other non-current assets	5,243	488
End of period	$ 158,354	$ 115,050

The Company and Summary of Sign

The Company and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
The Company and Summary of Significant Accounting Policies	1. The Company and Summary of Significant Accounting Policies The Company Proofpoint, Inc. (“Proofpoint”, “we”, “us”, “our” or the “Company”) was incorporated in Delaware in June 2002 and is headquartered in California. Proofpoint is a leading security-as-a-service provider that enables large and mid-sized organizations worldwide to defend, protect, archive and govern their most sensitive data. The Company’s security-and compliance platform is comprised of an integrated suite of threat protection, information protection, and brand protection solutions, including email protection, advanced threat protection, email authentication, data loss prevention, SaaS application protection, response orchestration and automation, digital risk, web browser isolation, email encryption, archiving, eDiscovery, supervision, secure communication, phishing simulation and security awareness computer-based training. Correction of Classification of Short-term and Long-term Deferred Revenue Management has determined that in the Company’s consolidated financial statements for the year ended December 31, 2018, short-term deferred revenue was overstated by $2,446, or 0.5%, in its consolidated balance sheet as of December 31, 2018. The Company has revised the December 31, 2018 consolidated balance sheet to correct the classification from short-term deferred revenue to long-term deferred revenue. The correction had no impact on the results of operations or cash flows of the Company. Basis of Presentation and Consolidation These condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. These condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“GAAP”), pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and note disclosures have been condensed or omitted pursuant to such rules and regulations. The accompanying Condensed Consolidated Balance Sheet as of December 31, 2018 is derived from audited financial statements as of that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the periods presented. The results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or for other interim periods or for future years. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and accompanying notes for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC. The Company’s significant accounting policies are described in Note 1 to those audited consolidated financial statements. Use of Estimates The preparation of financial statements in conformity with 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 expenses during the reporting period. Actual results could differ from those estimates and such difference may be material to the financial statements. Goodwill and Intangible Assets Goodwill represents the excess of the purchase price of the acquired enterprise over the fair value of identifiable assets acquired and liabilities assumed. The Company performs an annual goodwill impairment test during the fourth quarter of a calendar year and more frequently if an event or circumstances indicates that impairment may have occurred. For the purposes of impairment testing, the Company has determined that it has one operating segment and one reporting unit. The Company performs a two-step impairment test of goodwill whereby the fair value of the reporting unit is compared to its carrying value. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not considered impaired and further testing is not required. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, then the Company must perform the second step of the impairment test in order to determine the implied fair value of the reporting unit’s goodwill. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, then impairment loss equal to the difference is recorded. The identification and measurement of goodwill impairment involves the estimation of the fair value of the Company. The estimate of fair value of the Company, based on the best information available as of the date of the assessment, is subjective and requires judgment, including management assumptions about expected future revenue forecasts and discount rates, changes in the overall economy, trends in the stock price and other factors. No impairment indicators were identified by the Company as of June 30 , 201 9 . Intangible assets consist of developed technology, customer relationships, non-compete arrangements, trademarks and patents and order backlog. The values assigned to intangibles are based on estimates and judgments regarding expectations for success and life cycle of solutions and technologies acquired. Intangible assets are amortized on a straight-line basis over their estimated lives, which approximate the pattern in which the economic benefits of the intangible assets are consumed, as follows (in years): Low High Patents 4 5 Developed technology 3 7 Customer relationships 2 8 Order backlog 1 3 Trade names and trademarks 1 5 Comprehensive Loss Comprehensive loss includes all changes in equity that are not the result of transactions with stockholders. The Company’s comprehensive loss consists of its net loss and changes in unrealized gains (losses) from its available-for-sale investments. The Company had no material reclassifications out of accumulated other comprehensive loss into net loss for the three and six months ended June 30, 2019 and 2018. Accounting Pronouncements Adopted in 2019 In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) The Company adopted ASU 2016-02 in the first quarter of 2019, utilizing the modified retrospective transition approach through a cumulative-effect adjustment to the opening accumulated deficit balance as of January 1, 2019. Refer to Note 6 “Leases” for more information regarding the impact of the adoption of ASU 2016-02 on the Company's financial statements. Recent Accounting Pronouncements Not Yet Effective In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment purchase price allocation to measure goodwill impairment. A goodwill impairment charge will be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The update to the standard is effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted, and should be applied prospectively. The Company does not expect ASU 2017-04 to have a material impact on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

Revenue, Deferred Revenue and D

Revenue, Deferred Revenue and Deferred Contract Costs	6 Months Ended
	Jun. 30, 2019
Revenue From Contract With Customer [Abstract]
Revenue, Deferred Revenue and Deferred Contract Costs	2. Revenue, Deferred Revenue and Deferred Contract Costs The core principle of ASC 606 is to recognize revenue to depict the transfer of services or products to customers in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services or products. The principle is achieved through the following five-step approach: • Identification of the contract, or contracts, with the customer • Identification of the performance obligation in the contract • Determination of the transaction price • Allocation of the transaction price to the performance obligations in the contract • Recognition of revenue when, or as, the Company satisfies a performance obligation The Company generates sales directly through its sales team and, to a growing extent, through its channel partners. Sales to channel partners are made at a discount and revenues are recorded at this discounted price once all revenue recognition criteria are met. Channel partners generally receive an order from an end-customer prior to placing an order with the Company, and these partners do not carry any inventory of the Company’s products or solutions. Payment from channel partners is not contingent on the partner’s success in sales to end-customers. In the event that the Company offers rebates, joint marketing funds, or other incentive programs to a partner, recorded revenues are reduced by these amounts accordingly. Payment terms on invoiced amounts are typically 30 to 45 days. Disaggregation of Revenue The Company derives its revenue primarily from: (1) subscription service revenue; (2) subscription software revenue, and (3) hardware and services, which include professional service and training revenue provided to customers related to their use of the platform. The following table presents the Company’s revenue disaggregation: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Subscription service revenue $ 207,074 $ 165,365 $ 401,476 $ 317,985 Subscription software revenue 3,706 3,654 8,888 9,821 Hardware and services 3,659 2,856 7,012 6,530 Total revenue $ 214,439 $ 171,875 $ 417,376 $ 334,336 Subscription service revenue Subscription service revenue is derived from a subscription-based enterprise licensing model with contract terms typically ranging from one to three years, and consists of (1) subscription fees from the licensing of the Company’s security-as-a-service platform and it’s various components, (2) subscription fees for software with support and related future updates where the software updates are critical to the customers’ ability to derive benefit from the software due to the fast changing nature of the technology. These function together as one performance obligation, and (3) subscription fees for the right to access the Company’s customer support services for software with significant standalone functionality and support services for hardware. The hosted on-demand service arrangements do not provide customers with the right to take possession of the software supporting the hosted services. Support revenue is derived from ongoing security updates, upgrades, bug fixes, and maintenance. A time-elapsed method is used to measure progress because the Company transfers control evenly over the contractual period. Accordingly, the fixed consideration related to subscription service revenue is generally recognized on a straight-line basis over the contract term beginning on the date access is provided, as long as other revenue recognition criteria have been met. Most of the company’s contracts are non-cancelable over the contract term. Customers typically have the right to terminate their contract for cause if the Company fails to perform in accordance with the contractual terms. Some of the Company’s customers have the option to purchase additional subscription services at a stated price. These options are evaluated on a case-by-case basis but generally do not provide a material right as they are priced at or above the Company’s SSP and, as such, would not result in a separate performance obligation. Subscription software revenue Subscription software revenue is primarily derived from term-based software that is deployed on the customers’ own servers and has significant standalone functionality, is recognized upon transfer of control to the customer. The control for subscription software is transferred at the later of delivery to the customer or the software license start date. Hardware and services Hardware revenue consists of amounts derived from the sale of the Company’s on-premise hardware appliance, which is recognized upon passage of control, which occurs upon shipment of the product. Professional services revenue consists of fees associated with consulting, implementation and training services for assisting customers in implementing and expanding the use of the Company’s services and products. These services are distinct from subscription, subscription software licenses and hardware. Professional services do not result in significant customization of the Company’s services and products. The Company recognizes revenue related to the professional services as they are performed. Contracts with multiple performance obligations Most of the Company’s contracts with customers contain multiple performance obligations that are distinct and accounted for separately. The transaction price allocated to subscription services and subscription software that does not have significant standalone functionality is determined by considering factors such as historical pricing practices, and the selling price of hardware and professional services is estimated using a cost plus model. The selling price for support of a functional subscription software license is calculated as a percentage of functional subscription software license value which is derived by analyzing internal pricing practice, customer expectations, and industry practice. Variable Consideration Revenue from sales is recorded at the net sales price, which is the transaction price, and includes estimates of variable consideration. The amount of variable consideration that is included in the transaction price is constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue will not occur when the uncertainty is resolved. If the Company’s services or products do not meet certain service level commitments, the Company’s customers are entitled to receive service credits representing a form of variable consideration. The Company has not historically experienced any significant incidents affecting the defined levels of reliability and performance as required by the Company’s subscription contracts. Accordingly, any estimated refunds related to these contracts in the condensed consolidated financial statements are not material during the periods presented. Unbilled accounts receivables Unbilled accounts receivable represents amounts for which the Company has recognized revenue, pursuant to its revenue recognition policy, for software licenses already delivered and professional services already performed, but billed in arrears and for which the Company believes it has an unconditional right to payment. The unbilled accounts receivable balance, included in accounts receivable in the condensed consolidated balance sheet, was $1,861 Deferred commissions The Company capitalizes sales commissions and associated payroll taxes paid to internal sales personnel, and referral fees paid to independent third-parties, that are incremental to the acquisition of customer contracts. These costs are recorded as deferred commissions on the condensed consolidated balance sheets. The Company determines whether costs should be deferred based on its sales compensation plans, if the commissions are incremental and would not have occurred absent the customer contract. Sales commissions for renewal of a subscription contract are not considered commensurate with the commissions paid for the acquisition of the initial subscription contract given the substantive difference in commission rate between new and renewal contracts. Commissions paid upon the initial acquisition of a contract are amortized over an estimated period of benefit of five years while commissions paid related to renewal contracts are amortized over a contractual renewal period. Amortization is recognized based on the expected future revenue streams under the customer contracts. Amortization of deferred sales commissions is included in sales and marketing expense in the accompanying condensed consolidated statements of operations. The Company determines the period of benefit for commissions paid for the acquisition of the initial subscription contract by taking into consideration its initial estimated customer life and the technological life of the Company’s software and related significant features. The Company classifies deferred commissions as current or long-term based on the timing of when the Company expects to recognize the expense. The Company periodically reviews these deferred commission costs to determine whether events or changes in circumstances have occurred that could impact the period of benefit of these deferred contract acquisition costs. There were no material impairment losses recorded during the periods presented. For the three months ended June 30, 2019 and 2018, the Company capitalized $18,063 and $12,715 of commission costs, respectively, and amortized $12,400 and $8,334, respectively. For the six months ended June 30, 2019 and 2018, the Company capitalized $30,978 and $21,929 of commission costs, respectively, and amortized $23,671 and $16,708, respectively. Deferred product costs Deferred product costs are the incremental costs to fulfill a contract that are directly associated with each non-cancellable customer contract and primarily consist of royalty payments made to third parties, from whom the Company has obtained licenses to integrate certain software into its products. The deferred product costs are recognized based on the contractual term, and included in cost of revenue in the accompanying condensed consolidated statements of operations. The Company classifies deferred product costs as current or long-term based on the timing of when the Company expects to recognize the expense. For the three months ended June 30, 2019 and 2018, the Company capitalized $889 and $758 of deferred product costs, respectively, and amortized $694 and $611, respectively. For the six months ended June 30, 2019 and 2018, the Company capitalized $1,576 and $1,436 of deferred product costs, respectively, and amortized $1,481and $1,183, respectively. Deferred revenue The Company records deferred revenue when cash payments are received, or invoices are issued in advance of the Company’s performance, and generally recognizes revenue over the contractual term. The Company recognized $187,447 and $149,817 of revenue during the three months ended June 30, 2019 and 2018, respectively, that was included in the deferred revenue balances at the beginning of the respective periods. The Company recognized $328,985 and $237,395 of revenue during the six months ended June 30, 2019 and 2018, respectively, that was included in the deferred revenue balances at the beginning of the respective periods. The Company recognized $1,639 and $2,091 of revenue during the three months ended June 30, 2019 and 2018, respectively, related to the performance obligations satisfied in prior periods. The Company recognized $1,811 and $2,584 of revenue during the six months ended June 30, 2019 and 2018, respectively, related to the performance obligations satisfied in prior periods. Remaining performance obligations Contracted revenue as of June 30, 2019 that has not yet been recognized (“contracted not recognized”) was $499,452, which includes deferred revenue and non-cancellable amounts that will be invoiced and recognized as revenue in future periods and excludes contracts with an original expected length of one year or less. The Company expects 60% 37%

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Acquisitions	3. Acquisitions Acquisitions are accounted for under the purchase method of accounting in which the tangible and identifiable intangible assets and liabilities of each acquired company are recorded at their respective fair values as of each acquisition date, including an amount for goodwill representing the difference between the respective acquisition consideration and fair values of identifiable net assets. The Company believes that for the acquisitions below, the combined entities will achieve savings in corporate overhead costs and opportunities for growth through expanded geographic and customer segment diversity with the ability to leverage additional products and capabilities. These factors, among others, contributed to a purchase price in excess of the estimated fair value of the acquired companies’ net identifiable assets acquired and, as a result, goodwill was recorded in connection with the acquisitions. Goodwill related to the acquisition of Meta Networks, Ltd. is deductible for tax purposes, and goodwill related to the acquisition of Wombat Security Technologies, Inc. is not deductible for tax purposes. While the Company uses its best estimates and assumptions as part of the purchase price allocation process to value assets acquired and liabilities assumed at the acquisition date, these estimates and assumptions are subject to refinement. When additional information becomes available, such as finalization of negotiations of working capital adjustments and tax related matters, the Company may revise its preliminary purchase price allocation. As a result, during the preliminary purchase price allocation period, which may be up to one year from the acquisition date, the Company may record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. Subsequent to the purchase price allocation period, adjustments to assets acquired or liabilities assumed are recognized in the operating results. 2019 Acquisition Meta Networks, Ltd. On May 15, 2019 (the “Meta Networks Acquisition Date”), pursuant to the terms of the share purchase agreement, the Company acquired all shares of Meta Networks, Ltd. (“Meta Networks”), an innovator in zero trust network access. By combining Meta Networks’ innovative zero trust network access technology with the Company’s people-centric security capabilities the Company will make it far simpler for enterprises to precisely control employee and contractor access to on-premises, cloud, and consumer applications. These factors, among others, contributed to a purchase price in excess of the estimated fair value of acquired net identifiable assets and, as a result, goodwill was recorded in connection with the acquisition. The Company has estimated fair values of acquired tangible assets, intangible assets and liabilities at the Meta Networks Acquisition Date. The amounts reported are considered provisional as the Company is completing the valuation work to determine the fair value of certain assets and liabilities acquired, largely with respect to working capital adjustments. The results of operations and the provisional fair values of the acquired assets and liabilities assumed have been included in the accompanying condensed consolidated financial statements since the Meta Networks Acquisition Date. At the Meta Networks Acquisition Date, the consideration transferred was $104,895, net of cash acquired of $104. Of the consideration transferred, $12,500 was held in escrow to secure indemnification obligations, which has not been released as of the issuance of the condensed consolidated financial statements. The Company incurred $853 in acquisition-related costs which were recorded within operating expenses for the six months ended June 30, 2019. The revenue from Meta Networks was not material for the six months ended June 30, 2019, and due to the continued integration of the combined businesses, it was impractical to determine the earnings. Per the terms of the share purchase agreement, unvested stock options and unvested restricted stock units held by Meta Networks employees were canceled and exchanged for the Company’s unvested stock options and unvested restricted stock units, respectively. The fair value of $185 of these unvested awards was attributed to pre-combination services and included in consideration transferred. The fair value of $12,918 was allocated to post-combination services. The unvested awards are subject to the recipient’s continued service with the Company, and $12,918 will be recognized ratably as stock-based compensation expense over the required remaining service period. Also, as part of the share purchase The following table summarizes the fair values of tangible assets acquired, liabilities assumed, intangible assets and goodwill: Estimated Fair Value Estimated Useful Life (in years) Current assets $ 356 N/A Fixed assets 68 N/A Core/developed technology 21,000 3 Deferred tax liability, net (1,854 ) N/A Other liabilities (440 ) N/A Goodwill 85,869 Indefinite $ 104,999 2018 Acquisition Wombat Security Technologies, Inc. On February 28, 2018 (the “Wombat Acquisition Date”), pursuant to the terms of the merger agreement, the Company acquired all shares of Wombat Security Technologies, Inc. (“Wombat”), a leader for phishing simulation and security awareness computer-based training. By collecting data from Wombat’s PhishAlarm solution, the Company has access to data on phishing campaigns as seen by non-Company customers, providing broader visibility and insight to the Proofpoint Nexus platform. With this acquisition, the Company’s customers can leverage the industry’s first solution combining the Company’s advanced threat protection with Wombat’s phishing simulation and computer-based security awareness training. With the combined solutions, the Company’s customers can: • Use real detected phishing attacks for simulations, assessing users based on the threats that are actually targeting them; • Both investigate and take action on user-reporting phishing, leveraging orchestration and automation to find real attacks, quarantine emails in users’ inboxes, and lock user accounts to limit risk; • Train users in the moment immediately after they click for both simulated and real phishing attacks. The Company also expects to achieve savings in corporate overhead costs for the combined entities. These factors, among others, contributed to a purchase price in excess of the estimated fair value of acquired net identifiable assets and, as a result, goodwill was recorded in connection with the acquisition. At the Wombat Acquisition Date, the consideration transferred was $222,215, net of cash acquired of $13,452. Of the consideration transferred, $22,500 was held in escrow to secure indemnification obligations, which has not been released as of the filing date of this Quarterly Report on Form 10-Q. Per the terms of the merger agreement, unvested in-the-money stock options held by Wombat employees were canceled and paid off using the same amount per option as for the common share less applicable exercise price for each option. The fair value of $1,580 of these unvested options was attributed to pre-combination service and included in consideration transferred. The fair value of unvested options of $1,571 was allocated to post-combination services and expensed in the three months ended March 31, 2018. Also, as part of the merger agreement, 51 shares of the Company’s common stock were deferred for certain key employees with the total fair value of $5,458 (see Note 9 “Equity Award Plans”), which was not included in the purchase price. The deferred shares are subject to forfeiture if employment terminates prior to the lapse of the restrictions, and their fair value is expensed as stock-based compensation expense over the vesting period. The following table summarizes the fair values of tangible assets acquired, liabilities assumed, intangible assets and goodwill: Fair Value Estimated Useful Life (in years) Current assets $ 23,344 N/A Fixed assets 954 N/A Customer relationships 37,800 7 Order backlog 6,800 2 Core/developed technology 35,200 4 Trade name 2,400 4 Deferred revenue (14,700 ) N/A Deferred tax liability, net (14,725 ) N/A Other liabilities (1,120 ) N/A Goodwill 159,714 Indefinite $ 235,667 Pro Forma Financial Information (unaudited) The following unaudited pro forma financial information presents the combined results of operations for the three and six months ended June 30, 2019 and 2018 as though the Meta Networks and Wombat acquisitions that occurred during the reporting periods had occurred as of the beginning of the comparable prior reporting periods, with adjustments to give effect to pro forma events that are directly attributable to the acquisition such as amortization expense of acquired intangible assets, stock-based compensation directly attributable to the acquisition and acquisition-related transaction costs. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the acquisition had occurred at the beginning of the period presented, nor are they indicative of future results of operations: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Total revenue $ 214,477 $ 171,880 $ 417,484 $ 340,981 Net loss $ (30,440 ) $ (38,841 ) $ (62,894 ) $ (56,419 ) Basic and diluted net loss per share $ (0.55 ) $ (0.76 ) $ (1.14 ) $ (1.11 )

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	4. Goodwill and Intangible Assets The goodwill activity and balances are presented below: Beginning balance as of December 31, 2018 $ 460,425 Acquisition during period 85,869 Purchase accounting adjustments (3,151 ) Closing balance as of June 30, 2019 $ 543,143 Intangible assets, excluding goodwill, consisted of the following: June 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed technology $ 175,069 $ (93,792 ) $ 81,277 $ 154,069 $ (79,525 ) $ 74,544 Customer relationships 71,400 (20,237 ) 51,163 71,400 (15,166 ) 56,234 Trade names and patents 3,330 (1,830 ) 1,500 3,330 (1,430 ) 1,900 Order backlog 6,800 (4,533 ) 2,267 6,800 (2,833 ) 3,967 $ 256,599 $ (120,392 ) $ 136,207 $ 235,599 $ (98,954 ) $ 136,645 Amortization of intangible assets expense was $11,139 and $11,241 for the three months ended June 30, 2019 and 2018, respectively, and $21,438 and $19,447 for the six months ended June 30, 2019 and 2018, respectively. Future estimated amortization of intangible assets expense as of June 30, 2019 are presented below: Year ending December 31, 2019, remainder $ 22,896 2020 41,966 2021 38,098 2022 16,017 2023 7,312 Thereafter 9,918 $ 136,207

Fair Value Measurements and Inv

Fair Value Measurements and Investments	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements and Investments	5. Fair Value Measurements and Investments Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (i.e., the “exit price”) in an orderly transaction between market participants at the measurement date. A hierarchy for inputs used in measuring fair value has been defined to minimize the use of unobservable inputs by requiring the use of observable market data when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on active market data. Unobservable inputs are inputs that reflect the Company’s assumptions about the assumptions market participants would use in pricing the asset or liability based on the best information available in the circumstances. The fair value hierarchy prioritizes the inputs into three broad levels: • Level 1: Quoted (unadjusted) prices in active markets for identical assets or liabilities. The Company’s Level 1 assets generally consist of money market funds. • Level 2: Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability. The Company’s Level 2 assets and liabilities generally consist of corporate debt securities, commercial papers, U.S. agency and Treasury securities. • Level 3: Unobservable inputs to the valuation methodology that are supported by little or no market activity and that are significant to the measurement of the fair value of the assets or liabilities. Level 3 assets and liabilities include those whose fair value measurements are determined using pricing models, discounted cash flow methodologies or similar valuation techniques, as well as significant management judgment or estimation. The following tables summarize, for each category of assets or liabilities carried at fair value, the respective fair value as of June 30, 2019 and December 31, 2018 and the classification by level of input within the fair value hierarchy: June 30, 2019 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 117,031 $ 117,031 $ — $ — Commercial paper 5,995 — 5,995 — Short-term investments: Commercial paper 25,901 — 25,901 — Corporate debt securities 5,108 — 5,108 — U.S. Treasury securities 1,999 — 1,999 — Total financial assets $ 156,034 $ 117,031 $ 39,003 $ — December 31, 2018 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 133,202 $ 133,202 $ — $ — Commercial paper 12,478 — 12,478 — Short-term investments: Corporate debt securities 13,470 — 13,470 — Commercial paper 30,838 — 30,838 — U.S. Treasury securities 1,999 — 1,999 — Total financial assets $ 191,987 $ 133,202 $ 58,785 $ — Investments The cost and fair value of the Company’s cash and cash equivalents and available-for-sale investments as of June 30, 2019 and December 31, 2018 were as follows: June 30, 2019 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 26,671 $ — $ — $ 26,671 Money market funds 117,031 — — 117,031 Commercial paper 5,995 — — 5,995 Total $ 149,697 $ — $ — $ 149,697 Short-term investments: Commercial paper $ 25,901 $ — $ — $ 25,901 Corporate debt securities 5,106 2 — 5,108 U.S. Treasury securities 1,999 — — 1,999 Total $ 33,006 $ 2 $ — $ 33,008 December 31, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 39,712 $ — $ — $ 39,712 Money market funds 133,202 — — 133,202 Commercial paper 12,478 — — 12,478 Total $ 185,392 $ — $ — $ 185,392 Short-term investments: Corporate debt securities $ 13,477 $ — $ (7 ) $ 13,470 Commercial paper 30,838 — — 30,838 U.S. Treasury securities 1,999 — — 1,999 Total $ 46,314 $ — $ (7 ) $ 46,307 As of June 30, 2019 and December 31, 2018, all investments mature in less than one year. Estimated fair values for marketable securities are based on quoted market prices for the same or similar instruments. The Company reviews its investments on a quarterly basis to identify and evaluate investments that have an indication of possible impairment and has determined that no other-than-temporary impairments were required to be recognized during the three and six months ended June 30, 2019 and 2018.

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	6. Leases The Company determines if an arrangement is, or contains, a lease at inception. Operating leases are included in operating right-of-use assets and operating lease liabilities in the condensed consolidated balance sheets. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments based on the lease contracts. Operating lease ROU assets and liabilities were recognized at adoption date or lease commencement date, if the commencement date was after January 1, 2019, based on the present value of lease payments over the remaining lease term. The Company’s lease contracts do not provide an implicit rate, as such the Company used its incremental borrowing rate based on the information available at adoption date or lease commencement date, if the commencement date was after January 1, 2019, in determining the present value of lease payments. The operating lease ROU assets also include any lease payments made to the lessors at or before the lease commencement date, and excludes lease incentives. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense is recognized on a straight-line basis over the lease term. The Company has operating leases for corporate offices, research and development facilities, sales and marketing offices, and data centers. The Company adopted ASC 842 in the first quarter of 2019, utilizing the modified retrospective transition approach through a cumulative-effect adjustment to the opening accumulated deficit as of January 1, 2019. Upon adoption of ASC 842, the Company elected: • The package of practical expedients which allows for not reassessing (1) whether existing contracts contain leases, (2) the lease classification for existing leases, and (3) whether existing initial direct costs meet the new definition. • The practical expedient in ASC Subtopic 842-10 to not separate non-lease components from lease components for its real estate and data center leases and instead account for each separate lease component and non-lease components associated with that lease component as a single lease component. • Not to recognize ROU assets and lease liabilities for short-term leases, which have a lease term of twelve months or less. The following table summarizes the effects of adopting ASC 842: Ending Balance as of December 31, 2018 Adjustments Opening Balance as of January 1, 2019 Assets Prepaid expenses and other current assets $ 16,872 $ (81 ) $ 16,791 Operating lease right-of-use assets $ — $ 59,549 $ 59,549 Liabilities Accounts payable $ 20,237 $ (216 ) $ 20,021 Deferred rent $ 829 $ (829 ) $ — Operating lease liabilities $ — $ 24,820 $ 24,820 Long-term operating lease liabilities $ — $ 39,361 $ 39,361 Long-term deferred rent $ 3,757 $ (3,757 ) $ — Stockholders’ Equity Accumulated deficit $ (595,418 ) $ 89 $ (595,329 ) The real estate leases have remaining lease terms for one to eight years, some of which include options to extend the lease period up to ten years. The data center leases have remaining lease terms of one year to three years, some of which have renewal periods of one year. In October 2018, the Company entered into a 127 month lease agreement to lease approximately 242,400 square feet of corporate office space in Sunnyvale, California, which is expected to become the Company’s new corporate headquarters beginning in 2020. The property will be constructed by the landlord, with the completion date expected to occur between April and August 2020 which is when the lease is expected to commence, as such no ROU assets or related lease liabilities were recorded in the condensed financial statements for the three and six months ended June 30, 2019. The lease contains a rent holiday period, scheduled rent increases, lease incentives, and renewal option which allow the lease term to be extended by 5 years. Base rental payments will be approximately $161,300 over the lease term. The components of lease expense were as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Operating lease cost $ 6,391 $ 12,731 Short-term lease cost 709 1,347 Variable lease cost 853 1,708 Total lease cost $ 7,953 $ 15,786 Supplemental information related to leases was as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Cash paid for amounts included in the measurement of operating lease liabilities $ 5,938 $ 12,832 Right-of-use assets obtained in exchange for operating lease obligations $ 3,234 $ 3,979 Weighted-average remaining lease term - operating leases 4 years Weighted-average discount rate - operating leases 4.83 % Maturities of lease liabilities as of June 30, 2019 were as follows: Operating leases Year ending December 31, 2019 $ 12,831 2020 18,053 2021 11,027 2022 7,573 2023 5,529 Thereafter 8,215 Total lease payments 63,228 Less imputed interest (6,257 ) Total $ 56,971 Premises rent expense were $2,754 and $5,375 for the three and six months ended June 30, 2018, respectively. As previously disclosed in the Company’s 2018 Annual Report on Form 10-K and under ASC-840, future minimum lease payments for operating leases having initial or remaining noncancelable lease terms in excess of one year as of December 31, 2018 would have been as follows: Operating leases 2019 $ 25,313 2020 17,535 2021 19,155 2022 21,581 2023 19,609 Thereafter 129,154 Total minimum lease payments $ 232,347

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Contingencies Contingencies Under the indemnification provisions of the Company’s customer agreements, the Company agrees to indemnify and defend and hold harmless its customers against, among other things, infringement of any patent, trademark or copyright under any country’s laws or the misappropriation of any trade secret arising from the customers’ legal use of the Company’s solutions. The exposure to the Company under these indemnification provisions is generally limited to the total amount paid by the customers under the applicable customer agreement. However, certain indemnification provisions potentially expose the Company to losses in excess of the aggregate amount paid to the Company by the customer under the applicable customer agreement. To date, there have been no claims against the Company or its customers pursuant to these indemnification provisions. Legal Contingencies From time to time, the Company may be involved in legal proceedings and subject to claims in the ordinary course of business. For lawsuits where the Company is the defendant, the Company is in the process of defending these litigation matters, and while there can be no assurances and the outcomes of these matters are currently not determinable, the Company currently believes that there are no existing claims or proceedings that are likely to have a material adverse effect on the Company’s financial position, results of operations or cash flows.

Convertible Senior Notes

Convertible Senior Notes	6 Months Ended
	Jun. 30, 2019
Senior Longterm Notes Current And Noncurrent [Abstract]
Convertible Senior Notes	8. Convertible Senior Notes 0.75% Convertible Senior Notes due June 2020 On June 17, 2015, the Company issued $200,000 principal amount of 0.75% Convertible Senior Notes (the “0.75% Notes”) due 2020 in a private offering to qualified institutional buyers (“Holders”) pursuant to Rule 144A under the Securities Act of 1934, as amended (the “Securities Act”). The initial Holders of the 0.75% Notes also had an option to purchase an additional $30,000 in principal amount which was exercised in full. The net proceeds after the agent’s discount and issuance costs of $6,581 from the 0.75% Notes offering were approximately $223,419. The Company used the net proceeds for working capital and general corporate purposes, which included funding the Company’s operations, capital expenditures, and acquisitions of businesses, products or technologies. The 0.75% Notes b ore interest at 0.75% per year, payable semi-annually in arrears every June 15 and December 15, beginning on December 15, 2015. During the quarter ended September 30, 2018, $229,869 of the principal amount of the 0.75% Notes was converted into 2,928 shares of common stock, with the remaining $142 repaid in cash. The shares of common stock had a fair value of $336,994 at the time of the conversion. This transaction resulted in a $7,207 loss on extinguishment that was included in interest expense in the Consolidated Statement of Operations. The loss on extinguishment was calculated as the difference between the fair value amount allocated to the liability component on the date of conversion and net carrying amount of the liability component. For the three and six months ended June 30, 2019 and 2018, the Company incurred the following expenses related to the convertible senior notes: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Interest expense related to contractual interest coupon $ — $ 431 $ — $ 862 Amortization of debt discount and issuance costs — 3,100 — 6,153 Total $ — $ 3,531 $ — $ 7,015

Equity Award Plans

Equity Award Plans	6 Months Ended
	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Award Plans	9. Equity Award Plans Stock-Based Compensation Plans On March 30, 2012, the Board of Directors and the Company’s stockholders approved the 2012 Equity Incentive Plan (the “2012 Plan”), which became effective in April 2012. The 2012 Plan was amended, effective June 2019, when the Company’s stockholders approved an Amended and Restated 2012 Equity Incentive Plan (the “Amended 2012 Plan”) at the annual meeting of the stockholders on June 6, 2019. The Company has seven equity incentive plans: the Company’s 2002 stock option plan (the “2002 Plan”), the Amended 2012 Plan and five plans assumed by the Company upon various business acquisitions. The assumed plans are the Cloudmark plan, the WebLife plan, the Meta Networks plan, and two FireLayers plans. Upon the Company’s initial public offering, all shares that were reserved under the 2002 Plan but not issued, and shares issued but subsequently returned to the plan through forfeitures, cancellations and repurchases became part of the 2012 Plan and no further shares will be granted pursuant to the 2002 Plan. No further shares will be granted pursuant to the assumed plans. All outstanding stock awards under the 2002 Plan, the assumed plans and Amended 2012 Plan will continue to be governed by their existing terms. Under the Amended 2012 Plan, the Company has the ability to issue incentive stock options (“ISOs”), nonstatutory stock options (“NSOs”), restricted stock awards, stock bonus awards, stock appreciation rights (“SARs”), restricted stock units (“RSUs”), and performance stock units (“PSUs”). The Amended 2012 Plan also allows direct issuance of common stock to employees, outside directors and consultants at prices equal to the fair market value at the date of grant of options or issuance of common stock. Additionally, the Amended 2012 Plan provides for the grant of performance cash awards to employees, directors and consultants. The Company has the right to repurchase any unvested shares (at the option exercise price) of common stock issued directly or under option exercises. The right of repurchase generally expires over the vesting period. Stock bonus and other liability awards are accounted for as liability-classified awards, because the obligations are based predominantly on fixed monetary amounts that are generally known at the inception of the obligation, to be settled with a variable number of shares of the Company’s common stock. Under the equity incentive plans, the term of an option grant shall not exceed ten years from the date of its grant and options generally vest over a three to four-year period, with vesting on a monthly or annual interval. As of June 30, 2019, 7,960 shares were available for future grant. Restricted stock awards generally vest over a four-year period. The Company net-share settles equity awards held by employees by withholding shares upon vesting to satisfy tax withholding obligations. The shares withheld to satisfy employee tax withholding obligations are returned to the Company’s Amended 2012 Plan and will be available for future issuance. Payments for employee’s tax obligations to the tax authorities are recognized as a reduction to additional paid-in capital and reflected as financing activities in the Company’s consolidated statements of cash flows. Stock Options There were no options granted during the three and six months ended June 30, 2019 and 2018. The Company realized no income tax benefit from stock option exercises in each of the periods presented due to recurring losses and the valuation allowances for deferred tax assets. Stock option activity under the Plan is as follows: Shares subject to Options Outstanding Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Balance at December 31, 2018 1,255 $ 28.67 4.77 $ 69,224 Options assumed per business acquisition 34 3.07 Options exercised (157 ) 18.17 Options forfeited and expired — — Balance at June 30, 2019 1,132 $ 29.36 4.49 $ 102,846 The total intrinsic value of options exercised was $16,078 and $27,181 for the six months ended June 30, 2019 and 2018, respectively. Total cash proceeds from such option exercises were $2,876 and $4,276 for the six months ended June 30, 2019 and 2018, respectively. The fair value of option grants that vested was $815 and $1,925 for the six months ended June 30, 2019 and 2018, respectively. As of June 30, 2019, the Company had unamortized stock-based compensation expense of $5,319 related to stock options that will be recognized over the average remaining vesting term of the options of 1.55 years. Restricted Stock and Performance Stock Units A following table summarized the activity of RSUs and PSUs: RSUs and PSUs Outstanding Number of Shares Granted Fair Value Per Unit Awarded and unvested at December 31, 2018 4,568 $ 89.88 Awards assumed per business acquisition 76 119.13 Awards granted 968 119.10 Awards vested (779 ) 92.86 Awards forfeited (244 ) 94.55 Awarded and unvested at June 30, 2019 4,589 $ 95.77 As of June 30, 2019, there was $316,606 of unamortized stock-based compensation expense related to unvested RSUs, which is expected to be recognized over a weighted average period of 3.48 years. The Company granted 161 and 166 shares of PSUs in the six months ended June 30, 2019 and 2018, respectively. The PSU vesting conditions were based on individual performance targets. Unamortized stock-based compensation expense was $23,518 as of June 30, 2019. Stock Bonus and Other Liability Awards The total accrued liability for the stock bonus and other liability awards was $6,484 and $12,741 as of June 30, 2019 and December 31, 2018, respectively. During the six months ended June 30, 2019 and 2018, 107 and 61 shares, respectively, of common stock earned under the stock bonus program were issued. Stock-based compensation expense related to stock bonus program was $6,484 and $6,022 for the six months ended June 30, 2019 and 2018, respectively. In March 2015, the Company issued liability awards with a fair value of $6,885, which vested annually over a three-year period and were subject to continuous service and other conditions. The liability was settled with a variable number of shares of the Company’s common stock. During the six months ended June 30, 2018, 20 shares were vested and issued. The Company recognized $408 of stock-based compensation expense related to these liability awards in the six months ended June 30, 2018. There were no outstanding liability awards as of December 31, 2018. Employee Stock Purchase Plan On March 30, 2012, the Board of Directors and the Company’s stockholders approved the 2012 Employee Stock Purchase Plan (the “ESPP”), which became effective in April 2012. A total of 745 shares of the Company’s common stock were initially reserved for future issuance under the ESPP. The number of shares reserved for issuance under the ESPP will increase automatically on January 1 of each of the first eight years commencing with 2013 by the number of shares equal to 1% of the Company’s shares outstanding on the immediately preceding December 31, but not to exceed 1,490 shares, unless the Board of Directors, in its discretion, determines to make a smaller increase. As of June 30, 2019, there were 2,277 shares of the Company’s common stock available for future issuance under the ESPP. As of June 30, 2019, the Company expects to recognize $2,664 of the total unamortized compensation cost related to employee purchases under the ESPP over a weighted average period of 0.4 years. Restricted Stock and Deferred Shares The Company granted 111 shares of restricted stock in 2016 to certain key employees with the total fair value of $8,669 with annual vesting term of three years. The Company recognized $1,432 of stock-based compensation expense in each of the six months ended June 30, 2019 and 2018. As of June 30, 2019, there was $917 of unamortized stock-based compensation expense related to the unvested shares of restricted stock. The shares of restricted stock are subject to forfeiture if employment terminates prior to the lapse of the restrictions, and are expensed over the vesting period. They are considered issued and outstanding shares of the Company at the grant date and have the same rights as other shares of common stock. As part of the WebLife acquisition in 2017, 107 shares were deferred for certain key employees with the total fair value of $9,652, and a vesting period between three and four years. The Company recognized $1,197 of stock-based compensation in each of the six months ended June 30, 2019 and 2018, respectively. As of June 30, 2019, there was $5,835 of unamortized stock-based compensation expense related to the unvested deferred shares. The deferred shares are subject to forfeiture if employment terminates prior to the lapse of the deferral date, and are expensed over the vesting period. As part of the Wombat acquisition in 2018, 51 shares were deferred for certain key employees with the total fair value of $5,458, and a vesting period of two years. The Company recognized $1,598 and $912 of stock-based compensation in the six months ended June 30, 2019 and 2018, respectively. As of June 30, 2019, there was $1,572 of unamortized stock-based compensation expense related to the unvested deferred shares. The deferred shares are subject to forfeiture if employment terminates prior to the lapse of the deferral date, and are expensed over the vesting period. As part of the Meta Networks acquisition in 2019, 72 shares were deferred for certain key employees with the total fair value of $8,338 allocated to post-combination expense, and a vesting period of three years. The Company recognized $350 of stock-based compensation in the three months ended June 30, 2019. As of June 30, 2019, there was $7,988 of unamortized stock-based compensation expense related to the unvested deferred shares. The deferred shares are subject to forfeiture if employment terminates prior to the lapse of the deferral date and are expensed over the vesting period. They are considered issued and outstanding shares of the Company at the acquisition date and have the same rights as other shares of common stock.

Net Loss per Share

Net Loss per Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Net Loss per Share	10. Net Loss per Share Basic net loss per share of common stock is calculated by dividing the net loss by the weighted‑average number of shares of common stock outstanding for the period. The weighted‑average number of shares of common stock used to calculate basic net loss per share of common stock excludes those shares subject to repurchase related to stock options or restricted stock that were exercised or issued prior to vesting as these shares are not deemed to be issued for accounting purposes until they vest. Diluted net loss per share of common stock is computed by dividing the net loss using the weighted‑average number of shares of common stock, excluding common stock subject to repurchase, and, if dilutive, potential shares of common stock outstanding during the period. Basic and diluted net loss per common share was the same for all periods presented as the impact of all potentially dilutive securities outstanding was anti-dilutive. The following table presents the potentially dilutive common shares outstanding that were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive: June 30, 2019 June 30, 2018 Stock options to purchase common stock 1,132 1,741 Restricted stock units 4,589 3,738 Employee stock purchase plan 244 97 Common stock subject to repurchase 54 181 Bonus and other liability awards 114 53 0.75% Convertible senior notes — 2,831 Total 6,133 8,641

Segment Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment Reporting	11. Segment Reporting Operating segments are reported in a manner consistent with the internal reporting supported and defined by the components of an enterprise about which separate financial information is available, provided and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The Company’s Chief Executive Officer reviews financial information presented on a consolidated basis. The Company has one business activity, and there are no segment managers who are held accountable for operations, operating results and plans for levels or components below the consolidated unit level. Accordingly, the Company determined that it has one operating and reportable segment. The following sets forth total revenue by solutions offered by the Company and by geographic area. Revenue by geographic area is based upon the billing address of the customer: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Total revenue by solution: Advanced Threat $ 156,569 $ 129,208 $ 307,894 $ 252,821 Compliance 57,870 42,667 109,482 81,515 Total revenue $ 214,439 $ 171,875 $ 417,376 $ 334,336 Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Total revenue: United States $ 172,682 $ 140,504 $ 336,101 $ 274,160 Rest of world 41,757 31,371 81,275 60,176 Total revenue $ 214,439 $ 171,875 $ 417,376 $ 334,336 Long-lived assets by geographic area are presented below: June 30, 2019 December 31, 2018 Long-lived assets: United States $ 57,841 $ 57,682 Rest of world 12,847 12,945 Total long-lived assets $ 70,688 $ 70,627

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes The Company’s quarterly provision for income taxes is based on an estimated effective annual income tax rate. The Company’s quarterly provision for income taxes also includes the tax impact of certain unusual or infrequently occurring items, if any, including changes in judgment about valuation allowances and effects of changes in tax laws or rates, in the interim period in which they occur. Income tax expense for the three and six months ended June 30, 2019 was $280 and $900 on pre-tax losses of $28,633 and $56,291, respectively. The Company recognized income tax expense of $114 and benefit of $13,958 on pre-tax losses of $34,184 and $60,412 for the three and six months ended June 30, 2018, respectively. The income tax rate for the three and six months ended June 30, 2019 varied from the United States statutory income tax rate primarily due to valuation allowances in the United States whereby pre-tax losses and income do not result in the recognition of corresponding income tax benefits and expenses. The income tax rate for the three and six months ended June 30, 2018 varied from the United States statutory income tax rate primarily due to valuation allowances in the United States whereby pre-tax losses and income do not result in the recognition of corresponding income tax benefits and expenses and also the recognition of a $14,725 deferred tax benefit in the U.S. related to changes in the Company’s valuation allowance resulting from the Wombat business acquisition. The Company’s effective tax rate for the six months ended June 30, 2019 and 2018 was negative 2% and 23%, respectively. The Company reviews the likelihood that it will realize the benefit of its deferred tax assets and, therefore, the need for valuation allowances, on a quarterly basis. There is no corresponding income tax benefit recognized with respect to losses incurred and no corresponding income tax expense recognized with respect to earnings generated in jurisdictions with a valuation allowance. This causes variability in the Company’s effective tax rate. The Company intends to maintain the valuation allowances until it is more likely than not that the net deferred tax assets will be realized. During the three months ended March 31, 2017, the Company transferred certain intellectual property rights from its wholly owned subsidiary in Israel to the United States. Although the transfer of intellectual property rights between consolidated entities did not result in any gain in the consolidated statements of operations, the transfer did result in a taxable gain in Israel. In the Company’s financial statements ending before January 1, 2018, taxes incurred related to the intercompany transaction have been treated as a prepaid tax asset in the Company’s consolidated balance sheet and were being amortized to income tax expense over the life of the intellectual property. Effective January 1, 2018, pursuant to the Company’s modified retrospective adoption of ASU 2016-16, the Company’s remaining prepaid tax asset of $3,216 was recorded as an increase to accumulated deficit. As of June 30, 2019, the Company’s gross uncertain tax benefits totaled $18,138, excluding related accrued interest and penalties of $405. As of June 30, 2019, $4,915 of the Company’s uncertain tax benefits, including related accrued interest and penalties, would impact the effective tax rate if recognized. During the six months ended June 30, 2019, the Company’s gross uncertain tax benefits increased $1,684. The increase is comprised of a $1,481 increase for tax positions taken in the current period, a $209 increase for tax positions taken in prior periods, offset by a $6 decrease related to statute of limitation expirations. The Company is currently under audit by the Israel Tax Authority for tax years 2013 through 2017. Related to the audit by the Israel Tax Authority it is reasonably possible that the Company’s uncertain tax positions could change within the next 12 months. An estimate of the range of any change cannot be made. The Company believes it has recorded all appropriate provisions for all jurisdictions and open years. However, the Company can give no assurance that taxing authorities will not propose adjustments that would increase its tax liabilities. The Company is not currently under audit by the IRS or any similar taxing authority in any other material jurisdiction.

Defined Contribution Plan

Defined Contribution Plan	6 Months Ended
	Jun. 30, 2019
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Defined Contribution Plan	13. Defined Contribution Plan The Company’s tax-deferred savings plan is qualified under Section 401(k) of the United States Internal Revenue Code. Employees may make voluntary, tax-deferred contributions to the 401(k) Plan up to the statutorily prescribed annual limit. The Company makes discretionary matching contributions to the 401(k) Plan on behalf of employees up to the limit determined by the Board of Directors. The Company contributed $589 and $1,420, respectively, to the 401(k) Plan during the three and six months ended June 30, 2019. The Company contributed $958 to the 401(k) Plan during both the three and six months ended June 30, 2018.

The Company and Summary of Si_2

The Company and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation These condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. These condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“GAAP”), pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and note disclosures have been condensed or omitted pursuant to such rules and regulations. The accompanying Condensed Consolidated Balance Sheet as of December 31, 2018 is derived from audited financial statements as of that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair statement of the periods presented. The results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or for other interim periods or for future years. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and accompanying notes for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC. The Company’s significant accounting policies are described in Note 1 to those audited consolidated financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with 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 expenses during the reporting period. Actual results could differ from those estimates and such difference may be material to the financial statements.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill represents the excess of the purchase price of the acquired enterprise over the fair value of identifiable assets acquired and liabilities assumed. The Company performs an annual goodwill impairment test during the fourth quarter of a calendar year and more frequently if an event or circumstances indicates that impairment may have occurred. For the purposes of impairment testing, the Company has determined that it has one operating segment and one reporting unit. The Company performs a two-step impairment test of goodwill whereby the fair value of the reporting unit is compared to its carrying value. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not considered impaired and further testing is not required. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, then the Company must perform the second step of the impairment test in order to determine the implied fair value of the reporting unit’s goodwill. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, then impairment loss equal to the difference is recorded. The identification and measurement of goodwill impairment involves the estimation of the fair value of the Company. The estimate of fair value of the Company, based on the best information available as of the date of the assessment, is subjective and requires judgment, including management assumptions about expected future revenue forecasts and discount rates, changes in the overall economy, trends in the stock price and other factors. No impairment indicators were identified by the Company as of June 30 , 201 9 . Intangible assets consist of developed technology, customer relationships, non-compete arrangements, trademarks and patents and order backlog. The values assigned to intangibles are based on estimates and judgments regarding expectations for success and life cycle of solutions and technologies acquired. Intangible assets are amortized on a straight-line basis over their estimated lives, which approximate the pattern in which the economic benefits of the intangible assets are consumed, as follows (in years): Low High Patents 4 5 Developed technology 3 7 Customer relationships 2 8 Order backlog 1 3 Trade names and trademarks 1 5
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes all changes in equity that are not the result of transactions with stockholders. The Company’s comprehensive loss consists of its net loss and changes in unrealized gains (losses) from its available-for-sale investments. The Company had no material reclassifications out of accumulated other comprehensive loss into net loss for the three and six months ended June 30, 2019 and 2018.
New Accounting Pronouncements	Accounting Pronouncements Adopted in 2019 In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) The Company adopted ASU 2016-02 in the first quarter of 2019, utilizing the modified retrospective transition approach through a cumulative-effect adjustment to the opening accumulated deficit balance as of January 1, 2019. Refer to Note 6 “Leases” for more information regarding the impact of the adoption of ASU 2016-02 on the Company's financial statements. Recent Accounting Pronouncements Not Yet Effective In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment purchase price allocation to measure goodwill impairment. A goodwill impairment charge will be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The update to the standard is effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted, and should be applied prospectively. The Company does not expect ASU 2017-04 to have a material impact on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments
Leases	ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments based on the lease contracts. Operating lease ROU assets and liabilities were recognized at adoption date or lease commencement date, if the commencement date was after January 1, 2019, based on the present value of lease payments over the remaining lease term. The Company’s lease contracts do not provide an implicit rate, as such the Company used its incremental borrowing rate based on the information available at adoption date or lease commencement date, if the commencement date was after January 1, 2019, in determining the present value of lease payments. The operating lease ROU assets also include any lease payments made to the lessors at or before the lease commencement date, and excludes lease incentives. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense is recognized on a straight-line basis over the lease term. The Company has operating leases for corporate offices, research and development facilities, sales and marketing offices, and data centers. The Company adopted ASC 842 in the first quarter of 2019, utilizing the modified retrospective transition approach through a cumulative-effect adjustment to the opening accumulated deficit as of January 1, 2019. Upon adoption of ASC 842, the Company elected: • The package of practical expedients which allows for not reassessing (1) whether existing contracts contain leases, (2) the lease classification for existing leases, and (3) whether existing initial direct costs meet the new definition. • The practical expedient in ASC Subtopic 842-10 to not separate non-lease components from lease components for its real estate and data center leases and instead account for each separate lease component and non-lease components associated with that lease component as a single lease component. • Not to recognize ROU assets and lease liabilities for short-term leases, which have a lease term of twelve months or less.

Revenue, Deferred Revenue and_2

Revenue, Deferred Revenue and Deferred Contract Costs (Policies)	6 Months Ended
	Jun. 30, 2019
Revenue From Contract With Customer [Abstract]
Revenue Recognition	Subscription service revenue Subscription service revenue is derived from a subscription-based enterprise licensing model with contract terms typically ranging from one to three years, and consists of (1) subscription fees from the licensing of the Company’s security-as-a-service platform and it’s various components, (2) subscription fees for software with support and related future updates where the software updates are critical to the customers’ ability to derive benefit from the software due to the fast changing nature of the technology. These function together as one performance obligation, and (3) subscription fees for the right to access the Company’s customer support services for software with significant standalone functionality and support services for hardware. The hosted on-demand service arrangements do not provide customers with the right to take possession of the software supporting the hosted services. Support revenue is derived from ongoing security updates, upgrades, bug fixes, and maintenance. A time-elapsed method is used to measure progress because the Company transfers control evenly over the contractual period. Accordingly, the fixed consideration related to subscription service revenue is generally recognized on a straight-line basis over the contract term beginning on the date access is provided, as long as other revenue recognition criteria have been met. Most of the company’s contracts are non-cancelable over the contract term. Customers typically have the right to terminate their contract for cause if the Company fails to perform in accordance with the contractual terms. Some of the Company’s customers have the option to purchase additional subscription services at a stated price. These options are evaluated on a case-by-case basis but generally do not provide a material right as they are priced at or above the Company’s SSP and, as such, would not result in a separate performance obligation. Subscription software revenue Subscription software revenue is primarily derived from term-based software that is deployed on the customers’ own servers and has significant standalone functionality, is recognized upon transfer of control to the customer. The control for subscription software is transferred at the later of delivery to the customer or the software license start date. Hardware and services Hardware revenue consists of amounts derived from the sale of the Company’s on-premise hardware appliance, which is recognized upon passage of control, which occurs upon shipment of the product. Professional services revenue consists of fees associated with consulting, implementation and training services for assisting customers in implementing and expanding the use of the Company’s services and products. These services are distinct from subscription, subscription software licenses and hardware. Professional services do not result in significant customization of the Company’s services and products. The Company recognizes revenue related to the professional services as they are performed.
Contracts With Multiple Performance Obligations	Contracts with multiple performance obligations Most of the Company’s contracts with customers contain multiple performance obligations that are distinct and accounted for separately. The transaction price allocated to subscription services and subscription software that does not have significant standalone functionality is determined by considering factors such as historical pricing practices, and the selling price of hardware and professional services is estimated using a cost plus model. The selling price for support of a functional subscription software license is calculated as a percentage of functional subscription software license value which is derived by analyzing internal pricing practice, customer expectations, and industry practice.
Variable Consideration	Variable Consideration Revenue from sales is recorded at the net sales price, which is the transaction price, and includes estimates of variable consideration. The amount of variable consideration that is included in the transaction price is constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue will not occur when the uncertainty is resolved. If the Company’s services or products do not meet certain service level commitments, the Company’s customers are entitled to receive service credits representing a form of variable consideration. The Company has not historically experienced any significant incidents affecting the defined levels of reliability and performance as required by the Company’s subscription contracts. Accordingly, any estimated refunds related to these contracts in the condensed consolidated financial statements are not material during the periods presented.
Unbilled Accounts Receivables	Unbilled accounts receivables Unbilled accounts receivable represents amounts for which the Company has recognized revenue, pursuant to its revenue recognition policy, for software licenses already delivered and professional services already performed, but billed in arrears and for which the Company believes it has an unconditional right to payment. The unbilled accounts receivable balance, included in accounts receivable in the condensed consolidated balance sheet, was $1,861
Deferred Commissions	Deferred commissions The Company capitalizes sales commissions and associated payroll taxes paid to internal sales personnel, and referral fees paid to independent third-parties, that are incremental to the acquisition of customer contracts. These costs are recorded as deferred commissions on the condensed consolidated balance sheets. The Company determines whether costs should be deferred based on its sales compensation plans, if the commissions are incremental and would not have occurred absent the customer contract. Sales commissions for renewal of a subscription contract are not considered commensurate with the commissions paid for the acquisition of the initial subscription contract given the substantive difference in commission rate between new and renewal contracts. Commissions paid upon the initial acquisition of a contract are amortized over an estimated period of benefit of five years while commissions paid related to renewal contracts are amortized over a contractual renewal period. Amortization is recognized based on the expected future revenue streams under the customer contracts. Amortization of deferred sales commissions is included in sales and marketing expense in the accompanying condensed consolidated statements of operations. The Company determines the period of benefit for commissions paid for the acquisition of the initial subscription contract by taking into consideration its initial estimated customer life and the technological life of the Company’s software and related significant features. The Company classifies deferred commissions as current or long-term based on the timing of when the Company expects to recognize the expense. The Company periodically reviews these deferred commission costs to determine whether events or changes in circumstances have occurred that could impact the period of benefit of these deferred contract acquisition costs. There were no material impairment losses recorded during the periods presented. For the three months ended June 30, 2019 and 2018, the Company capitalized $18,063 and $12,715 of commission costs, respectively, and amortized $12,400 and $8,334, respectively. For the six months ended June 30, 2019 and 2018, the Company capitalized $30,978 and $21,929 of commission costs, respectively, and amortized $23,671 and $16,708, respectively.
Deferred Product Costs	Deferred product costs Deferred product costs are the incremental costs to fulfill a contract that are directly associated with each non-cancellable customer contract and primarily consist of royalty payments made to third parties, from whom the Company has obtained licenses to integrate certain software into its products. The deferred product costs are recognized based on the contractual term, and included in cost of revenue in the accompanying condensed consolidated statements of operations. The Company classifies deferred product costs as current or long-term based on the timing of when the Company expects to recognize the expense. For the three months ended June 30, 2019 and 2018, the Company capitalized $889 and $758 of deferred product costs, respectively, and amortized $694 and $611, respectively. For the six months ended June 30, 2019 and 2018, the Company capitalized $1,576 and $1,436 of deferred product costs, respectively, and amortized $1,481and $1,183, respectively.
Deferred Revenue	Deferred revenue The Company records deferred revenue when cash payments are received, or invoices are issued in advance of the Company’s performance, and generally recognizes revenue over the contractual term. The Company recognized $187,447 and $149,817 of revenue during the three months ended June 30, 2019 and 2018, respectively, that was included in the deferred revenue balances at the beginning of the respective periods. The Company recognized $328,985 and $237,395 of revenue during the six months ended June 30, 2019 and 2018, respectively, that was included in the deferred revenue balances at the beginning of the respective periods. The Company recognized $1,639 and $2,091 of revenue during the three months ended June 30, 2019 and 2018, respectively, related to the performance obligations satisfied in prior periods. The Company recognized $1,811 and $2,584 of revenue during the six months ended June 30, 2019 and 2018, respectively, related to the performance obligations satisfied in prior periods.

The Company and Summary of Si_3

The Company and Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Summary of Estimated Useful Life of Intangible Assets	Intangible assets are amortized on a straight-line basis over their estimated lives, which approximate the pattern in which the economic benefits of the intangible assets are consumed, as follows (in years): Low High Patents 4 5 Developed technology 3 7 Customer relationships 2 8 Order backlog 1 3 Trade names and trademarks 1 5

Revenue, Deferred Revenue and_3

Revenue, Deferred Revenue and Deferred Contract Costs (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue From Contract With Customer [Abstract]
Disaggregation of Revenue	The following table presents the Company’s revenue disaggregation: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Subscription service revenue $ 207,074 $ 165,365 $ 401,476 $ 317,985 Subscription software revenue 3,706 3,654 8,888 9,821 Hardware and services 3,659 2,856 7,012 6,530 Total revenue $ 214,439 $ 171,875 $ 417,376 $ 334,336

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2019
Business Acquisition [Line Items]
Pro Forma Financial Information of Business Acquisitions	Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the acquisition had occurred at the beginning of the period presented, nor are they indicative of future results of operations: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Total revenue $ 214,477 $ 171,880 $ 417,484 $ 340,981 Net loss $ (30,440 ) $ (38,841 ) $ (62,894 ) $ (56,419 ) Basic and diluted net loss per share $ (0.55 ) $ (0.76 ) $ (1.14 ) $ (1.11 )
Meta Networks, Ltd
Business Acquisition [Line Items]
Summary of the Fair Values of Tangible Assets Acquired, Liabilities Assumed, Intangible Assets and Goodwill	The following table summarizes the fair values of tangible assets acquired, liabilities assumed, intangible assets and goodwill: Estimated Fair Value Estimated Useful Life (in years) Current assets $ 356 N/A Fixed assets 68 N/A Core/developed technology 21,000 3 Deferred tax liability, net (1,854 ) N/A Other liabilities (440 ) N/A Goodwill 85,869 Indefinite $ 104,999
Wombat
Business Acquisition [Line Items]
Summary of the Fair Values of Tangible Assets Acquired, Liabilities Assumed, Intangible Assets and Goodwill	The following table summarizes the fair values of tangible assets acquired, liabilities assumed, intangible assets and goodwill: Fair Value Estimated Useful Life (in years) Current assets $ 23,344 N/A Fixed assets 954 N/A Customer relationships 37,800 7 Order backlog 6,800 2 Core/developed technology 35,200 4 Trade name 2,400 4 Deferred revenue (14,700 ) N/A Deferred tax liability, net (14,725 ) N/A Other liabilities (1,120 ) N/A Goodwill 159,714 Indefinite $ 235,667

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill Activity and Balances	The goodwill activity and balances are presented below: Beginning balance as of December 31, 2018 $ 460,425 Acquisition during period 85,869 Purchase accounting adjustments (3,151 ) Closing balance as of June 30, 2019 $ 543,143
Components of Intangible Assets, Excluding Goodwill	Intangible assets, excluding goodwill, consisted of the following: June 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed technology $ 175,069 $ (93,792 ) $ 81,277 $ 154,069 $ (79,525 ) $ 74,544 Customer relationships 71,400 (20,237 ) 51,163 71,400 (15,166 ) 56,234 Trade names and patents 3,330 (1,830 ) 1,500 3,330 (1,430 ) 1,900 Order backlog 6,800 (4,533 ) 2,267 6,800 (2,833 ) 3,967 $ 256,599 $ (120,392 ) $ 136,207 $ 235,599 $ (98,954 ) $ 136,645
Future Estimated Amortization Cost of Intangible Assets	Future estimated amortization of intangible assets expense as of June 30, 2019 are presented below: Year ending December 31, 2019, remainder $ 22,896 2020 41,966 2021 38,098 2022 16,017 2023 7,312 Thereafter 9,918 $ 136,207

Fair Value Measurements and I_2

Fair Value Measurements and Investments (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Summary of Assets or Liabilities Carried at Fair Value	The following tables summarize, for each category of assets or liabilities carried at fair value, the respective fair value as of June 30, 2019 and December 31, 2018 and the classification by level of input within the fair value hierarchy: June 30, 2019 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 117,031 $ 117,031 $ — $ — Commercial paper 5,995 — 5,995 — Short-term investments: Commercial paper 25,901 — 25,901 — Corporate debt securities 5,108 — 5,108 — U.S. Treasury securities 1,999 — 1,999 — Total financial assets $ 156,034 $ 117,031 $ 39,003 $ — December 31, 2018 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 133,202 $ 133,202 $ — $ — Commercial paper 12,478 — 12,478 — Short-term investments: Corporate debt securities 13,470 — 13,470 — Commercial paper 30,838 — 30,838 — U.S. Treasury securities 1,999 — 1,999 — Total financial assets $ 191,987 $ 133,202 $ 58,785 $ —
Summary of Cost and Fair Value of Cash and Cash Equivalents and Available-for-Sale Investments	The cost and fair value of the Company’s cash and cash equivalents and available-for-sale investments as of June 30, 2019 and December 31, 2018 were as follows: June 30, 2019 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 26,671 $ — $ — $ 26,671 Money market funds 117,031 — — 117,031 Commercial paper 5,995 — — 5,995 Total $ 149,697 $ — $ — $ 149,697 Short-term investments: Commercial paper $ 25,901 $ — $ — $ 25,901 Corporate debt securities 5,106 2 — 5,108 U.S. Treasury securities 1,999 — — 1,999 Total $ 33,006 $ 2 $ — $ 33,008 December 31, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents: Cash $ 39,712 $ — $ — $ 39,712 Money market funds 133,202 — — 133,202 Commercial paper 12,478 — — 12,478 Total $ 185,392 $ — $ — $ 185,392 Short-term investments: Corporate debt securities $ 13,477 $ — $ (7 ) $ 13,470 Commercial paper 30,838 — — 30,838 U.S. Treasury securities 1,999 — — 1,999 Total $ 46,314 $ — $ (7 ) $ 46,307

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of Component of Lease Expense and Supplemental Information Related to Leases	The components of lease expense were as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Operating lease cost $ 6,391 $ 12,731 Short-term lease cost 709 1,347 Variable lease cost 853 1,708 Total lease cost $ 7,953 $ 15,786 Supplemental information related to leases was as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Cash paid for amounts included in the measurement of operating lease liabilities $ 5,938 $ 12,832 Right-of-use assets obtained in exchange for operating lease obligations $ 3,234 $ 3,979 Weighted-average remaining lease term - operating leases 4 years Weighted-average discount rate - operating leases 4.83 %
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities as of June 30, 2019 were as follows: Operating leases Year ending December 31, 2019 $ 12,831 2020 18,053 2021 11,027 2022 7,573 2023 5,529 Thereafter 8,215 Total lease payments 63,228 Less imputed interest (6,257 ) Total $ 56,971
Schedule of Future Annual Minimum Lease Payments under Non-cancellable Lease	As previously disclosed in the Company’s 2018 Annual Report on Form 10-K and under ASC-840, future minimum lease payments for operating leases having initial or remaining noncancelable lease terms in excess of one year as of December 31, 2018 would have been as follows: Operating leases 2019 $ 25,313 2020 17,535 2021 19,155 2022 21,581 2023 19,609 Thereafter 129,154 Total minimum lease payments $ 232,347
ASC 842
Summary of Effects of Adopting ASC 842	The following table summarizes the effects of adopting ASC 842: Ending Balance as of December 31, 2018 Adjustments Opening Balance as of January 1, 2019 Assets Prepaid expenses and other current assets $ 16,872 $ (81 ) $ 16,791 Operating lease right-of-use assets $ — $ 59,549 $ 59,549 Liabilities Accounts payable $ 20,237 $ (216 ) $ 20,021 Deferred rent $ 829 $ (829 ) $ — Operating lease liabilities $ — $ 24,820 $ 24,820 Long-term operating lease liabilities $ — $ 39,361 $ 39,361 Long-term deferred rent $ 3,757 $ (3,757 ) $ — Stockholders’ Equity Accumulated deficit $ (595,418 ) $ 89 $ (595,329 )

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	6 Months Ended
	Jun. 30, 2019
Senior Longterm Notes Current And Noncurrent [Abstract]
Summary of Expenses Related to Convertible Senior Notes	For the three and six months ended June 30, 2019 and 2018, the Company incurred the following expenses related to the convertible senior notes: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Interest expense related to contractual interest coupon $ — $ 431 $ — $ 862 Amortization of debt discount and issuance costs — 3,100 — 6,153 Total $ — $ 3,531 $ — $ 7,015

Equity Award Plans (Tables)

Equity Award Plans (Tables)	6 Months Ended
	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Option Activity under Stock Incentive Plan	Stock option activity under the Plan is as follows: Shares subject to Options Outstanding Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Balance at December 31, 2018 1,255 $ 28.67 4.77 $ 69,224 Options assumed per business acquisition 34 3.07 Options exercised (157 ) 18.17 Options forfeited and expired — — Balance at June 30, 2019 1,132 $ 29.36 4.49 $ 102,846
Summary of RSUs and PSUs under Stock Incentive Plan	A following table summarized the activity of RSUs and PSUs: RSUs and PSUs Outstanding Number of Shares Granted Fair Value Per Unit Awarded and unvested at December 31, 2018 4,568 $ 89.88 Awards assumed per business acquisition 76 119.13 Awards granted 968 119.10 Awards vested (779 ) 92.86 Awards forfeited (244 ) 94.55 Awarded and unvested at June 30, 2019 4,589 $ 95.77

Net Loss per Share (Tables)

Net Loss per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Schedule of Potentially Dilutive Common Shares Outstanding that were Excluded from the Computation of Diluted Net Loss per Share	The following table presents the potentially dilutive common shares outstanding that were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive: June 30, 2019 June 30, 2018 Stock options to purchase common stock 1,132 1,741 Restricted stock units 4,589 3,738 Employee stock purchase plan 244 97 Common stock subject to repurchase 54 181 Bonus and other liability awards 114 53 0.75% Convertible senior notes — 2,831 Total 6,133 8,641

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Summary of Total Revenue by Solutions Offered by the Company	The following sets forth total revenue by solutions offered by the Company and by geographic area. Revenue by geographic area is based upon the billing address of the customer: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Total revenue by solution: Advanced Threat $ 156,569 $ 129,208 $ 307,894 $ 252,821 Compliance 57,870 42,667 109,482 81,515 Total revenue $ 214,439 $ 171,875 $ 417,376 $ 334,336
Summary of Total Revenue and Long-lived Assets by Geographic Area	Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Total revenue: United States $ 172,682 $ 140,504 $ 336,101 $ 274,160 Rest of world 41,757 31,371 81,275 60,176 Total revenue $ 214,439 $ 171,875 $ 417,376 $ 334,336 Long-lived assets by geographic area are presented below: June 30, 2019 December 31, 2018 Long-lived assets: United States $ 57,841 $ 57,682 Rest of world 12,847 12,945 Total long-lived assets $ 70,688 $ 70,627

The Company and Summary of Si_4

The Company and Summary of Significant Accounting Policies - Additional Information (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)segmentreporting_unit	Dec. 31, 2018USD ($)
Accounting Policies [Abstract]
Overstatement in Deferred revenue		$ 2,446,000
Overstatement in deferred revenue, percentage		0.50%
Number of operating and reportable segments | segment	1
Number of reporting units | reporting_unit	1
Goodwill, impairment loss	$ 0

The Company and Summary of Si_5

The Company and Summary of Significant Accounting Policies - Summary of Estimated Lives of Intangible Assets (Details)	6 Months Ended
	Jun. 30, 2019
Minimum | Patents
Intangible assets:
Estimated life of intangible assets	4 years
Minimum | Developed Technology
Intangible assets:
Estimated life of intangible assets	3 years
Minimum | Customer Relationships
Intangible assets:
Estimated life of intangible assets	2 years
Minimum | Order Backlog
Intangible assets:
Estimated life of intangible assets	1 year
Minimum | Trade Names and Trademarks
Intangible assets:
Estimated life of intangible assets	1 year
Maximum | Patents
Intangible assets:
Estimated life of intangible assets	5 years
Maximum | Developed Technology
Intangible assets:
Estimated life of intangible assets	7 years
Maximum | Customer Relationships
Intangible assets:
Estimated life of intangible assets	8 years
Maximum | Order Backlog
Intangible assets:
Estimated life of intangible assets	3 years
Maximum | Trade Names and Trademarks
Intangible assets:
Estimated life of intangible assets	5 years

Revenue, Deferred Revenue and_4

Revenue, Deferred Revenue and Deferred Contract Costs - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenue, Deferred Revenue and Deferred Contract Costs[Line Items]
Unbilled receivable	$ 1,861		$ 1,861		$ 1,276
Deferred revenue, revenue recognized	187,447	$ 149,817	328,985	$ 237,395
Revenue recognized related to the performance obligations satisfied in prior periods	1,639	2,091	1,811	2,584
Long-term Contract with Customer
Revenue, Deferred Revenue and Deferred Contract Costs[Line Items]
Contracted revenue not yet recognized	499,452		499,452
Sales Commission
Revenue, Deferred Revenue and Deferred Contract Costs[Line Items]
Contract cost capitalized	18,063	12,715	30,978	21,929
Contract cost amortized	12,400	8,334	23,671	16,708
Product Cost
Revenue, Deferred Revenue and Deferred Contract Costs[Line Items]
Contract cost capitalized	889	758	1,576	1,436
Contract cost amortized	$ 694	$ 611	$ 1,481	$ 1,183
Minimum
Revenue, Deferred Revenue and Deferred Contract Costs[Line Items]
Period terms for payment			30 days
Maximum
Revenue, Deferred Revenue and Deferred Contract Costs[Line Items]
Period terms for payment			45 days

Revenue, Deferred Revenue and_5

Revenue, Deferred Revenue and Deferred Contract Costs - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Total revenue	$ 214,439	$ 171,875	$ 417,376	$ 334,336
Subscription
Disaggregation of Revenue [Line Items]
Total revenue	207,074	165,365	401,476	317,985
Software License
Disaggregation of Revenue [Line Items]
Total revenue	3,706	3,654	8,888	9,821
Hardware and Service
Disaggregation of Revenue [Line Items]
Total revenue	$ 3,659	$ 2,856	$ 7,012	$ 6,530

Revenue, Deferred Revenue and_6

Revenue, Deferred Revenue and Deferred Contract Costs - Additional Information (Details 1) - Long-term Contract with Customer	Jun. 30, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of contracted and not recognized revenue to be recognized	60.00%
Revenue to be recognized period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of contracted and not recognized revenue to be recognized	37.00%
Revenue to be recognized period	2 years

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) - USD ($) shares in Thousands, $ in Thousands	May 15, 2019	Feb. 28, 2018	Jun. 30, 2019	Jun. 30, 2018
Business Acquisition [Line Items]
Preliminary purchase price allocation estimated period from the acquisition date		1 year
Payments to acquire businesses, net of cash acquired			$ 104,503	$ 223,786
Meta Networks, Ltd
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash acquired	$ 104,895
Cash acquired from acquisitions	104
Escrow	12,500
Acquisition-related costs			$ 853
Fair value of unvested awards attributed to pre-acquisition service	185
Fair value of unvested awards attributed to post-acquisition service	12,918
Deferred cash consideration	$ 7,827
Number of shares deferred	72
Deferred stock allocated to post-combination expense	$ 8,338
Stock-based compensation expense vesting period	3 years
Meta Networks, Ltd | Restricted Stock
Business Acquisition [Line Items]
Number of shares deferred	72
Fair value of share-based deferred cash compensation issued	$ 8,599
Deferred cash consideration allocated to post-combination expense	7,596
Deferred stock allocated to post-combination expense	$ 8,338
Stock-based compensation expense vesting period	3 years
Wombat
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash acquired		$ 222,215
Cash acquired from acquisitions		13,452
Escrow		22,500
Fair value of unvested awards attributed to pre-acquisition service		1,580
Fair value of unvested awards attributed to post-acquisition service		$ 1,571
Wombat | Restricted Stock
Business Acquisition [Line Items]
Number of shares deferred		51
Fair value of share-based deferred cash compensation issued		$ 5,458
Stock-based compensation expense vesting period		2 years

Acquisitions - Summary of the F

Acquisitions - Summary of the Fair Values of Tangible Assets Acquired, Liabilities Assumed, Intangible Assets and Goodwill (Details) - USD ($) $ in Thousands	May 15, 2019	Feb. 28, 2018	Jun. 30, 2019	Dec. 31, 2018
Fair value of assets acquired and liabilities assumed
Goodwill			$ 543,143	$ 460,425
Meta Networks, Ltd
Fair value of assets acquired and liabilities assumed
Current assets	$ 356
Fixed assets	68
Deferred tax liability, net	(1,854)
Other liabilities	(440)
Goodwill	85,869
Recognized identifiable assets acquired and liabilities assumed, net	104,999
Meta Networks, Ltd | Developed Technology
Fair value of assets acquired and liabilities assumed
Finite lived intangible assets	$ 21,000
Acquired finite-lived intangible assets, weighted average useful life (in years)	3 years
Wombat
Fair value of assets acquired and liabilities assumed
Current assets		$ 23,344
Fixed assets		954
Deferred revenue		(14,700)
Deferred tax liability, net		(14,725)
Other liabilities		(1,120)
Goodwill		159,714
Recognized identifiable assets acquired and liabilities assumed, net		235,667
Wombat | Developed Technology
Fair value of assets acquired and liabilities assumed
Finite lived intangible assets		$ 35,200
Acquired finite-lived intangible assets, weighted average useful life (in years)		4 years
Wombat | Customer Relationships
Fair value of assets acquired and liabilities assumed
Finite lived intangible assets		$ 37,800
Acquired finite-lived intangible assets, weighted average useful life (in years)		7 years
Wombat | Order Backlog
Fair value of assets acquired and liabilities assumed
Finite lived intangible assets		$ 6,800
Acquired finite-lived intangible assets, weighted average useful life (in years)		2 years
Wombat | Trade Names
Fair value of assets acquired and liabilities assumed
Finite lived intangible assets		$ 2,400
Acquired finite-lived intangible assets, weighted average useful life (in years)		4 years

Acquisitions - Pro Forma Financ

Acquisitions - Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Business Combinations [Abstract]
Total revenue	$ 214,477	$ 171,880	$ 417,484	$ 340,981
Net loss	$ (30,440)	$ (38,841)	$ (62,894)	$ (56,419)
Basic and diluted net loss per share	$ (0.55)	$ (0.76)	$ (1.14)	$ (1.11)

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Goodwill Activity and Balances (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Goodwill activity and balances
Beginning balance as of December 31, 2018	$ 460,425
Acquisition during period	85,869
Purchase accounting adjustments	(3,151)
Closing balance as of June 30, 2019	$ 543,143

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Components of Intangible Assets, Excluding Goodwill (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Intangible assets excluding goodwill:
Gross Carrying Amount	$ 256,599	$ 235,599
Accumulated Amortization	(120,392)	(98,954)
Net Carrying Amount	136,207	136,645
Developed Technology
Intangible assets excluding goodwill:
Gross Carrying Amount	175,069	154,069
Accumulated Amortization	(93,792)	(79,525)
Net Carrying Amount	81,277	74,544
Customer Relationships
Intangible assets excluding goodwill:
Gross Carrying Amount	71,400	71,400
Accumulated Amortization	(20,237)	(15,166)
Net Carrying Amount	51,163	56,234
Trade Names and Patents
Intangible assets excluding goodwill:
Gross Carrying Amount	3,330	3,330
Accumulated Amortization	(1,830)	(1,430)
Net Carrying Amount	1,500	1,900
Order Backlog
Intangible assets excluding goodwill:
Gross Carrying Amount	6,800	6,800
Accumulated Amortization	(4,533)	(2,833)
Net Carrying Amount	$ 2,267	$ 3,967

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Intangible assets excluding goodwill:
Intangible amortization expense	$ 11,139	$ 11,241	$ 21,438	$ 19,447

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Future Estimated Amortization of Intangible Assets Expense (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Future estimated amortization costs of intangible assets:
2019, remainder	$ 22,896
2020	41,966
2021	38,098
2022	16,017
2023	7,312
Thereafter	9,918
Net Carrying Amount	$ 136,207	$ 136,645

Fair Value Measurements and I_3

Fair Value Measurements and Investments - Summary of Assets or Liabilities Carried at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets
Cash equivalents	$ 149,697	$ 185,392
Short-term investments	33,008	46,307
Total financial assets	156,034	191,987
Level 1
Assets
Total financial assets	117,031	133,202
Level 2
Assets
Total financial assets	39,003	58,785
Money market funds
Assets
Cash equivalents	117,031	133,202
Money market funds | Level 1
Assets
Cash equivalents	117,031	133,202
Commercial paper
Assets
Cash equivalents	5,995	12,478
Short-term investments	25,901	30,838
Commercial paper | Level 2
Assets
Cash equivalents	5,995	12,478
Short-term investments	25,901	30,838
Corporate debt securities
Assets
Short-term investments	5,108	13,470
Corporate debt securities | Level 2
Assets
Short-term investments	5,108	13,470
U.S. Treasury securities
Assets
Short-term investments	1,999	1,999
U.S. Treasury securities | Level 2
Assets
Short-term investments	$ 1,999	$ 1,999

Fair Value Measurements and I_4

Fair Value Measurements and Investments - Summary of Cost and Fair Value of Cash and Cash Equivalents and Available-for-Sale Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule Of Cash And Cash Equivalents And Investments [Line Items]
Cash and cash equivalents, amortized cost	$ 149,697	$ 185,392
Cash and cash equivalents, unrealized gains	0	0
Cash and cash equivalents, unrealized losses	0	0
Cash and cash equivalents, fair value	149,697	185,392
Short-term investments, amortized cost	33,006	46,314
Short-term investments, unrealized gains	2	0
Short-term investments, unrealized losses	0	(7)
Short-term investments, fair value	33,008	46,307
Cash
Schedule Of Cash And Cash Equivalents And Investments [Line Items]
Cash and cash equivalents, amortized cost	26,671	39,712
Cash and cash equivalents, unrealized gains	0	0
Cash and cash equivalents, unrealized losses	0	0
Cash and cash equivalents, fair value	26,671	39,712
Money market funds
Schedule Of Cash And Cash Equivalents And Investments [Line Items]
Cash and cash equivalents, amortized cost	117,031	133,202
Cash and cash equivalents, unrealized gains	0	0
Cash and cash equivalents, unrealized losses	0	0
Cash and cash equivalents, fair value	117,031	133,202
Commercial paper
Schedule Of Cash And Cash Equivalents And Investments [Line Items]
Cash and cash equivalents, amortized cost	5,995	12,478
Cash and cash equivalents, unrealized gains	0	0
Cash and cash equivalents, unrealized losses	0	0
Cash and cash equivalents, fair value	5,995	12,478
Short-term investments, amortized cost	25,901	30,838
Short-term investments, unrealized gains	0	0
Short-term investments, unrealized losses	0	0
Short-term investments, fair value	25,901	30,838
Corporate debt securities
Schedule Of Cash And Cash Equivalents And Investments [Line Items]
Short-term investments, amortized cost	5,106	13,477
Short-term investments, unrealized gains	2	0
Short-term investments, unrealized losses	0	(7)
Short-term investments, fair value	5,108	13,470
U.S. Treasury securities
Schedule Of Cash And Cash Equivalents And Investments [Line Items]
Short-term investments, amortized cost	1,999	1,999
Short-term investments, unrealized gains	0	0
Short-term investments, unrealized losses	0	0
Short-term investments, fair value	$ 1,999	$ 1,999

Fair Value Measurements and I_5

Fair Value Measurements and Investments - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Maximum investment maturity term			1 year		1 year
Other-than-temporary impairments	$ 0	$ 0	$ 0	$ 0

Leases - Summary of Effects of

Leases - Summary of Effects of Adopting ASC 842 (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets
Prepaid expenses and other current assets	$ 21,300		$ 16,872
Operating lease right-of-use assets	52,156
Liabilities
Accounts payable	18,567		20,237
Deferred rent			829
Operating lease liabilities	22,510
Long-term operating lease liabilities	34,461
Long-term deferred rent			3,757
Stockholders’ equity:
Accumulated deficit	$ (652,520)		(595,418)
ASC 842
Assets
Prepaid expenses and other current assets		$ 16,791	16,872
Operating lease right-of-use assets		59,549
Liabilities
Accounts payable		20,021	20,237
Deferred rent			829
Operating lease liabilities		24,820
Long-term operating lease liabilities		39,361
Long-term deferred rent			3,757
Stockholders’ equity:
Accumulated deficit		(595,329)	$ (595,418)
ASC 842 | Adjustments
Assets
Prepaid expenses and other current assets		(81)
Operating lease right-of-use assets		59,549
Liabilities
Accounts payable		(216)
Deferred rent		(829)
Operating lease liabilities		24,820
Long-term operating lease liabilities		39,361
Long-term deferred rent		(3,757)
Stockholders’ equity:
Accumulated deficit		$ 89

Leases - Additional Information

Leases - Additional Information (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)	Oct. 31, 2018USD ($)ft²
Lessee Lease Description [Line Items]
Operating lease right-of-use assets		$ 52,156,000
Lease liabilities		$ 56,971,000
Operating lease rental payments over the lease term				$ 232,347,000
Operating lease rent expense	$ 2,754,000		$ 5,375,000
California
Lessee Lease Description [Line Items]
Operating lease agreement term					127 months
Operating lease agreement renewal term extended					5 years
Lease agreement corporate office space | ft²					242,400
Lease agreement description		beginning in 2020. The property will be constructed by the landlord, with the completion date expected to occur between April and August 2020 which is when the lease is expected to commence, as such no ROU assets or related lease liabilities were recorded in the condensed financial statements for the three and six months ended June 30, 2019.
Operating lease right-of-use assets		$ 0
Lease liabilities		$ 0
California | Over Lease Term
Lessee Lease Description [Line Items]
Operating lease rental payments over the lease term					$ 161,300,000
Real Estate Leases
Lessee Lease Description [Line Items]
Operating lease existence of option to extend		true
Operating lease option to extend, description		The real estate leases have remaining lease terms for one to eight years, some of which include options to extend the lease period up to ten years.
Real Estate Leases | Minimum
Lessee Lease Description [Line Items]
Operating lease agreement term		1 year
Real Estate Leases | Maximum
Lessee Lease Description [Line Items]
Operating lease agreement term		8 years
Operating lease agreement renewal term extended		10 years
Datacenter Leases
Lessee Lease Description [Line Items]
Operating lease agreement renewal term extended		1 year
Datacenter Leases | Minimum
Lessee Lease Description [Line Items]
Operating lease agreement term		1 year
Datacenter Leases | Maximum
Lessee Lease Description [Line Items]
Operating lease agreement term		3 years

Leases - Schedule of Component

Leases - Schedule of Component of Lease Expense and Supplemental Information Related to Leases (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018
Leases [Abstract]
Operating lease cost	$ 6,391	$ 12,731
Short-term lease cost	709	1,347
Variable lease cost	853	1,708
Total lease cost	7,953	15,786
Cash paid for amounts included in the measurement of operating lease liabilities	5,938	12,832
Operating lease right-of-use assets exchanged for lease obligations	$ 3,234	$ 3,979	$ 0
Weighted-average remaining lease term - operating leases	4 years	4 years
Weighted-average discount rate - operating leases	4.83%	4.83%

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
2019	$ 12,831
2020	18,053
2021	11,027
2022	7,573
2023	5,529
Thereafter	8,215
Total lease payments	63,228
Less imputed interest	(6,257)
Total	$ 56,971

Leases - Schedule of Future Ann

Leases - Schedule of Future Annual Minimum Lease Payments under Non-cancellable Lease (Details) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 25,313
2020	17,535
2021	19,155
2022	21,581
2023	19,609
Thereafter	129,154
Total minimum lease payments	$ 232,347

Convertible Senior Notes - Addi

Convertible Senior Notes - Additional Information (Details) - USD ($) shares in Thousands	Jun. 17, 2015	Sep. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Debt Instrument [Line Items]
Fair value of common stock shares converted			$ 12,651,000	$ 8,870,000
Senior Notes | 0.75% Convertible senior notes
Debt Instrument [Line Items]
Face amount	$ 200,000,000
Debt interest rate	0.75%
Option to purchase additional principal amount	$ 30,000,000
Agent's discount and issuance costs	6,581,000
Proceeds from issuance of convertible senior notes, net of discount	$ 223,419,000
Convertible senior notes converted to equity		$ 229,869,000
Shares of commons stock issued for conversion of convertible notes		2,928
Repayment of convertible notes		$ 142,000
Fair value of common stock shares converted		336,994,000
Loss on conversion of convertible notes		$ 7,207,000

Convertible Senior Notes - Summ

Convertible Senior Notes - Summary of Expenses Related to Convertible Senior Notes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest Expense, Debt
Amortization of debt discount and issuance costs			$ 0	$ 6,153
Senior Notes
Interest Expense, Debt
Interest expense related to contractual interest coupon	$ 0	$ 431	0	862
Amortization of debt discount and issuance costs	0	3,100	0	6,153
Total	$ 0	$ 3,531	$ 0	$ 7,015

Equity Award Plans - Stock-Base

Equity Award Plans - Stock-Based Compensation Plans - Additional Information (Details) shares in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019planshares	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity incentive plans held by the company (number of plans)	7
Equity Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant under the stock plans (in shares) | shares	7,960
Stock options to purchase common stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term until award expiration	10 years
Award vesting period	4 years
Stock options to purchase common stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Restricted Stock | Equity Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Various Acquisitions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity incentive plans held by the company (number of plans)	5
FireLayers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity incentive plans held by the company (number of plans)	2
FireLayers | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years

Equity Award Plans - Stock Opti

Equity Award Plans - Stock Options - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	0	0	0	0
Stock options to purchase common stock
Stock option activity under the Plan, in weighted average exercise price:
Aggregate intrinsic value, exercised			$ 16,078	$ 27,181
Proceeds from stock options exercised			2,876	4,276
Fair value of options, vested in period			815	$ 1,925
Unrecognized stock options compensation expense	$ 5,319		$ 5,319
Average remaining vesting term			1 year 6 months 18 days

Equity Award Plans - Stock Op_2

Equity Award Plans - Stock Option Activity under Stock Incentive Plan (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Stock option activity under the Plan
Outstanding, beginning of period (in shares)	1,255
Options assumed per acquisitions (in shares)	34
Options exercised (in shares)	(157)
Outstanding, ending of period (in shares)	1,132	1,255
Stock option activity under the Plan, in weighted average exercise price:
Balance at beginning of period (USD per share)	$ 28.67
Options assumed per business acquisition (USD per share)	3.07
Options exercised (USD per share)	18.17
Balance at ending of period (USD per share)	$ 29.36	$ 28.67
Weighted average remaining contractual term	4 years 5 months 26 days	4 years 9 months 7 days
Aggregate intrinsic value, outstanding	$ 102,846	$ 69,224

Equity Award Plans - Summary of

Equity Award Plans - Summary of RSUs and PSUs under Stock Incentive Plan (Details) - Restricted Stock Units and Performance Stock Units shares in Thousands	6 Months Ended
	Jun. 30, 2019$ / sharesshares
RSU's outstanding, number of shares:
Awarded at beginning of period (in shares) | shares	4,568
Awards assumed per business acquisition (in shares) | shares	76
Award granted (in shares) | shares	968
Awards vested (in shares) | shares	(779)
Awards forfeited (in shares) | shares	(244)
Awarded at end of period (in shares) | shares	4,589
RSUs outstanding, granted fair value per unit
Awarded at beginning of period (USD per share) | $ / shares	$ 89.88
Awards assumed per business acquisitions (USD per share) | $ / shares	119.13
Awards granted (USD per share) | $ / shares	119.10
Awards vested (USD per share) | $ / shares	92.86
Awards forfeited (USD per share) | $ / shares	94.55
Awarded at end of period (USD per share) | $ / shares	$ 95.77

Equity Award Plans - Restricted

Equity Award Plans - Restricted Stock and Performance Stock Units - Additional Information (Details) - USD ($) shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
RSU
RSUs outstanding, granted fair value per unit
Unamortized stock-based compensation expense	$ 316,606
Average remaining vesting term	3 years 5 months 23 days
Performance Shares
RSUs outstanding, granted fair value per unit
Unamortized stock-based compensation expense	$ 23,518
RSU's outstanding, number of shares:
Award granted (in shares)	161	166

Equity Award Plans - Stock Bonu

Equity Award Plans - Stock Bonus and Other Liability Awards - Additional Information (Details) - USD ($) shares in Thousands, $ in Thousands	Mar. 06, 2015	Mar. 31, 2016	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Bonus and other liability awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accrued liability for the stock bonus and other liability awards			$ 6,484		$ 12,741
Common stock issued (shares)			107	61
Stock-based compensation expense			$ 6,484	$ 6,022
Liability Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued (shares)				20
Stock-based compensation expense				$ 408
Fair value of liability award issued	$ 6,885				$ 0
Award vesting period		3 years

Equity Award Plans - Employee S

Equity Award Plans - Employee Stock Purchase Plan - Additional Information (Details) - ESPP 2012 Plan - USD ($) shares in Thousands, $ in Thousands	Mar. 30, 2012	Jun. 30, 2019
Employee stock purchase plan
Number of shares authorized ESPP (in shares)	745
Annual increase period	8 years
Maximum number of shares to be available for grant ESPP (in shares)	1,490
Shares available for future grant under the stock plans (in shares)		2,277
Annual percentage increase of maximum number of shares reserved for issuance ESPP	1.00%
Unamortized stock-based compensation expense		$ 2,664
Average remaining vesting term		4 months 24 days

Equity Award Plans - Restrict_2

Equity Award Plans - Restricted Stock and Deferred Shares - Additional Information (Details) - USD ($) shares in Thousands, $ in Thousands	May 15, 2019	Feb. 28, 2018	Nov. 30, 2017	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2016
Weblife | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense					$ 1,197	$ 1,197
Unamortized stock-based compensation expense				$ 5,835	$ 5,835
Number of shares deferred			107
Fair value of share-based deferred compensation issued			$ 9,652
Weblife | Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					3 years
Weblife | Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred shares service term					4 years
Wombat | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		2 years
Stock-based compensation expense					$ 1,598	912
Unamortized stock-based compensation expense				1,572	1,572
Number of shares deferred		51
Fair value of share-based deferred compensation issued		$ 5,458
Meta Networks
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Number of shares deferred	72
Deferred stock allocated to post-combination expense	$ 8,338
Meta Networks | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Stock-based compensation expense				350
Unamortized stock-based compensation expense				7,988	7,988
Number of shares deferred	72
Fair value of share-based deferred compensation issued	$ 8,599
Deferred stock allocated to post-combination expense	$ 8,338
Restricted Stock | FireLayers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted in period							111
Fair value of shares granted							$ 8,669
Award vesting period							3 years
Stock-based compensation expense					1,432	$ 1,432
Unamortized stock-based compensation expense				$ 917	$ 917

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Potentially Dilutive Common Shares Outstanding that were Excluded from the Computation of Diluted Net Loss per Share (Details) - shares shares in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Antidilutive securities excluded from computation of earnings per share
Total antidilutive securities excluded from computation of earnings per share (in shares)	6,133	8,641
Stock options to purchase common stock
Antidilutive securities excluded from computation of earnings per share
Total antidilutive securities excluded from computation of earnings per share (in shares)	1,132	1,741
Restricted stock units
Antidilutive securities excluded from computation of earnings per share
Total antidilutive securities excluded from computation of earnings per share (in shares)	4,589	3,738
Employee stock purchase plan
Antidilutive securities excluded from computation of earnings per share
Total antidilutive securities excluded from computation of earnings per share (in shares)	244	97
Common stock subject to repurchase
Antidilutive securities excluded from computation of earnings per share
Total antidilutive securities excluded from computation of earnings per share (in shares)	54	181
Bonus and other liability awards
Antidilutive securities excluded from computation of earnings per share
Total antidilutive securities excluded from computation of earnings per share (in shares)	114	53
0.75% Convertible senior notes | Convertible debt
Antidilutive securities excluded from computation of earnings per share
Total antidilutive securities excluded from computation of earnings per share (in shares)		2,831

Segment Reporting - Additional

Segment Reporting - Additional Information (Details)	6 Months Ended
	Jun. 30, 2019segment
Segment Reporting [Abstract]
Number of operating and reportable segments	1
Number of reportable segments	1

Segment Reporting - Summary of

Segment Reporting - Summary of Total Revenue by Solutions Offered by the Company (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue from external customers
Total revenue	$ 214,439	$ 171,875	$ 417,376	$ 334,336
Advanced Threat
Revenue from external customers
Total revenue	156,569	129,208	307,894	252,821
Compliance
Revenue from external customers
Total revenue	$ 57,870	$ 42,667	$ 109,482	$ 81,515

Segment Reporting - Summary o_2

Segment Reporting - Summary of Total Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment reporting:
Total revenue	$ 214,439	$ 171,875	$ 417,376	$ 334,336
United States
Segment reporting:
Total revenue	172,682	140,504	336,101	274,160
Rest of world
Segment reporting:
Total revenue	$ 41,757	$ 31,371	$ 81,275	$ 60,176

Segment Reporting - Summary o_3

Segment Reporting - Summary of Long-lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Segment reporting:
Total long-lived assets	$ 70,688	$ 70,627
United States
Segment reporting:
Total long-lived assets	57,841	57,682
Rest of world
Segment reporting:
Total long-lived assets	$ 12,847	$ 12,945

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2018
Valuation allowance
Income tax expense (benefit)	$ 280,000	$ 114,000	$ 900,000	$ (13,958,000)
Pre-tax loss	(28,633,000)	(34,184,000)	(56,291,000)	(60,412,000)
Deferred income tax benefit			$ (610,000)	$ (14,896,000)
Effective income tax rate			(2.00%)	23.00%
Unrecognized tax benefits	18,138,000		$ 18,138,000
Accrued interest and penalties	405,000		405,000
Uncertain tax benefits that would affect effective tax rate if recognized	$ 4,915,000		4,915,000
Increase (decrease) in gross uncertain tax benefits			1,684,000
Increase for tax positions taken in the current period			1,481,000
Decrease for tax positions taken in prior periods			209,000
Unrecognized tax benefits decrease related to statute of limitation expirations			6,000
ASU 2016-16
Valuation allowance
Increase in accumulated deficit due to ASU 2016-16 adoption					$ 3,216,000
Valuation Allowance
Valuation allowance
Income tax expense (benefit)			0
Operating Loss
Valuation allowance
Income tax expense (benefit)			$ 0
Wombat
Valuation allowance
Deferred income tax benefit		$ (14,725,000)		$ (14,725,000)

Defined Contribution Plan - Add

Defined Contribution Plan - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Defined contribution plan, employer discretionary matching contributions	$ 589	$ 958	$ 1,420	$ 958
Defined Contribution Plan, Tax Status [Extensible List]	us-gaap:QualifiedPlanMember	us-gaap:QualifiedPlanMember	us-gaap:QualifiedPlanMember	us-gaap:QualifiedPlanMember
Defined Contribution Plan, Sponsor Location [Extensible List]	country:US	country:US	country:US	country:US